CA1080659A - Opening and emptying of bags filled with bulk materials - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A method and apparatus for opening, emptying and disposing of 100 lb. paper, cloth or plastic bags of asbestos or other powdered or granular products by cutting longitudinally and transversely through one large bag face and perforating one or more remaining edges to produce a "U" or "H" shaped hinged flap through which the contents are emptied. Appro-priately located and sequentially actuated cutters, heated to from about 800°F. to about 1000°F., utilize heat and dropable to quickly and cleanly cut each bag on a hinged and dropable table while bag is held by arrangement of spikes which form a gripping head. Gripping head moves to discharge the empty bag from the apparatus. Air spikes on gripping head ensure complete emptying of bag contents, which flow down a discharge chute below the hinged table.

Description

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BACKGROUND OF TIIE INVENTION
Field of the Invention This invention relates to the opening and emptying of containers and more particularly to a method and apparatus for opening a~d emptying powdery or granular materials from large paper, cloth or plastic bags in which the material has been packaged, shipped or stored.
Description of the Prior Art The packaging, shipment and storage of bulk materials in bags and sacks has long been a common practice and numerous methods and mechanisms for rapidly opening and emptying various kinds of bags have been proposed. In most prior art systems some kind of sharp knife has been employed to cut the bag wall.
Among the problems encountered in previous systems for opening bags rapidly for emptying their contents, hazards to the safety of machine operators have been an important concern.
Workmen should, of course, be protected from being cut by rapidly moving knives, and the elimination of airborne dust and the prevention of fire are also necessary for safe working conditions. Certain materials often contained in the bags, such as asbestos, are themselves dangerous because of their toxic nature. As another example of the problems involved, a rapidly moving knife can cause sparks and fire by forcefully striking compacted particles when bags filled with cement powder are opened and emptied. Using present bag opening and emptying techniques, fine particles and paper shreds are often released into the air, causing fire and explosion hazards, as well as the danger of particle inhalation.

~k lO~V~;~9 Prior industri~l s~ste~s for op~ning and e~pt~ring bags have not provided efficie~cy and speed accoP?anied by optimum safety provisions.
~side from safety considerations, ~ag opening and ! emptying mechanisms of the prior art have often been specialized ~ for use in particular appli_ations and have not heen flexible j eno~yh for general use in the wide variety of industrial ¦ situations which require rapid emptying of bags of various sizes and shapes.
lo U.S.Patent ~o. 3,664,530 relates to apparatus in ¦ whic~. a bag of granular material is moved on a conveyor belt ¦ to a point at which a rotat ng circular cutter is moved across j the front end of the bag to slit open that end. Ther. the ¦ bag proceeds between~a pair of driven cutting wheels to slit open the sides of the bag, so that a U-shaped flap s formed.
As the bag moves over the end of the conveyor belt the weight of~ the bag contents causes the flap to open, discharging the contents into a hopper while pinch rolls grab the upper part I of the bag and push the emptied bag through an outlet. The ¦ 20 bag end cutter is returned to its original position and the - bag opening cycle~ is repeated. ~-Some prior art systems, such as that of U.S.Patent ¦ No. 2,930,501, have employed straight, rather than rotary, knives.
In U.S.Patent No. 3,415,147, heated means are sug-gested for severing textile fabric in making bags so as to separate the fabric along a line while heat sealing to prevent ravelling in the manufacture of bags. Another patent related to using a hot cutting device in making bags is U.S.Patent No. 3,406,612, but instead of employiny v~s~

temperatures suit;lble for mclting thermoplastic material as in the prcvious-ly mcntioned patent U.S. I'atent No. 3,406,612 suggests using a hot wire at a temperature of about 1300F. to char paper by brief contact.
Some of the aforementioned patents refer to associated apparatus for aiding in emptying and disposal of bags after they have been opened.
In U.S. Patent No. 3,467,267 air is blown into a sack after the sack has been cut through its middle, to push or pump out the contents.
SUM~ARY OF THE INVENTION
According to a first broad aspect of the present invention, there is provided a method of opening and emptying a bag substantially filled with substantially non-combustible particulate material comprising momentarily contacting a wall of the bag at each of the elemental areas continuously along a proposed line of cut therethrough using a dull cutting edge heated to a temperature above the kindling or melting temperature of the material of which said bag wall is made, said cutting edge being pressed against said elemental areas of the bag wall using said particulate material therein as a backing and minimal relative horizontal motion between said cutting edge and each of said elemental areas during said momentary contact, thereby to form a cut through only said bag wall by a combination of heat and pressure, and emptying said cut open bag of said particulate material.
According to another broad aspect of the present invention, there is provided a bag opening and empyting machine comprising table means for receiving a full bag to be opened and emptied, squaring means for rendering side and end walls of said bag substantially perpendicular to a lower bag wall when on said table means, cutting means having means for heating the same for cutting a bag by a combination of heat and pressure, said cutting means being mounted adjacent to said table means, means providing relative movement between said bag and said cutting means whereby at least one of said bag walls is contacted and pressed momentarily by said heated cutting means for producing a line of cut through the bag wall, and means for empty-ing said bag.

The bag opening and emptying arrangement of the present invention - A _4_ 10~ 59 climinates safety and llealtllll.lzards presentcd by prior art machincs whilc assuring quick ancl effective slitting ancl opening, and subsequent discharge of the bag contents in a closed, automatically controlled, yet flexible system. The system of the invention is complete in that it takes bags as they are conveyed sequentially into the apparatus, opens and empties them, provides for deposit of the emptied product into a hopper or chute, and disposes of each bag as it is emptied.
A wide variety of raw materials and products are currently stored and shipped in bags ranging in size from about 3" x 14" x 20" to about 12" x 28" x 48". Such bags may be of cloth, jute, burlap, multiwall paper, paper-plastic laminates, film plastic or woven-film laminates, or other suitably strong and flexible materials; are variously stitched or heat sealed; and may be provided with a valve or be of folded and glued con-struction. Machines in accordance with the invention automatically adjust to the size of the bags being handled, and the weight of material per bag ~-does not affect operation.

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Among the materials ordinarily packaged in non-porous bags are loose particulate substances such as sand, cement, asbestos, plastic powders and pellets, flour, etc., and solid caked material such as pressure packed asbestos.
~he system of the invention is capable of handling bags of any of these materials, typically emptying several bags per minute regardless of the weight of the bags.
Since the system is closed there is no danger of dust contamination from the emptying operation and safety devices prevent operator injury by moving parts.
The use of heated cutters to open a bag by means of a combination of heat and~pressure is an important feature of the invention. Polyethylene, often used for bags, melts at about 250F. Another popular bag material, kraft paper, has a kindling point of about 450F., but must be exposed to such a temperature for about 4 seconds for ignition to occur. In accordance with the present invention, a straight or circular cutting edge heated to a temperature over 800F.
and preferably between 850-900F. is briefly pressed against 20 a bag wall to form a cut. The pressure is provided either by the weight of the bag resting momentarily against the ~`
heated cutter, or by movement of the heated cutter into contact with the bag. Only ~.omentary contact is required, so there is no danger of ignition of paper bag material. It has been found that a dull cutting edge heated to a temperature of 850-g00F. and firmly pressed against a bag wall for a period of less than 1 second will cut the bag wall safely. A
period of contact of a heated cutting wheel edge with a bag wall of about 0.4 seconds has been found to be effective.
30 Thus a heated wheel of appropriate size passing along a bag at about 1 to 1.5 feet per second can be effectively employed.
A similar momentary contact of a heated, dull, straight blade edge is als~ effective.

'f In accordance with on~ ~mbodiment of th~ present inv~nticn, full b~g~ are fed on~ at a ti~e through a nor~ally closed door do~m an inclined infeed conveyor to a vibrating table at the end of which the hag impacts a retractable stop-~ate. This impact squares and flattens the for~ar~ end of the bag to ensure alignment ~ith, and backup for, subsequen.
cutting action. After impact and sauaring of the ~ag, the stopgate will retract. On the vibrating table, the bag is sguared between longitudinal squaring guides and a top plate flattens and compacts the bag and its contents. This action is aided by the vibration of the vibrating table After squaring and flattening of the bag are completed, a ~02lg I piston with a thrust plate at its for-7ard end pushes:~he bag ¦ foxward into a bas cutting station. As the bag travels throu~h--this cutting siation it passes beneath a rotating pincn xoll which, together with the longitudinal squaring guides, controls ! the bag shape. The pinch xoll also provides backup prëssure while guiding the bag against a pair of longitudinal cut~ers ¦ to a crosscut area. The pinch roll is preferably free rolling;:
but in some applications can be power driven.
The longitudinal cutters i2~ 021e embodiment of the ~^
invention are two freely rotating heated w~eels each aisposed at a substantially 45~ angle to the horizontal on OppOsite sides and facing inwardly of the bag to open cuts along the lower edges of the bag by a combination of heat and pxessure without burning of the bag or its contents. The free rolling cutter ~Jheel move~ent ~inimizes relative ~otion between the cutting edge and bag ~all, thereby ensuring steady, well -controlled, con,act time for the cuttin~ action. After two parallel cuts have been made by the longitudinal cutters at a subsequent cross-cut area, a heatea transverse cutter, which can also be in the form of a heated wheel, ~ut is preferably - an ~ongatea dull blade, connects the two lon~ituainal cuts to make an "~" or U" sh~ped arrangement of cuts in thc bottom side of the bag. The table on which the bag is resting when the transverse cut has been co~pleted has a hinged door arr-angement, so that upon ope~ing of the door or doors, the bag contents can fall into a hop?er or other container beneath the table.
~ ile the bag co- ents are dropping out, the bag itself is supported ~ro~ abol.-e by means of a bag engaging head which holds the upper side in place by mechanical engasement of 10 spikes that pierce the upper wall of the bag. Some of these spikes are hollo~ air spikes that aid in discharge of the con-tents by blowing air into t~e bag. After emptying, the open -bag is removed fro~ the cutting area, preferably by means of a cooperating arrangem.ent o- rolls and a reaction plate, for disposal, as by ba7ing, ~nd to make room for the next bag to be emptied. An air logic circuit can automatically control operation of the cooperating pistons, aates, doors and cutters for coordination of the movement of bags through the systemr An emergency override arransement is provided for such con- -tingencies as ~uick clearing of a "bad" bag from the apparatus~
- In an alternctive em~odiment of the invention par-ticularly suited to handlinc unusually heat sensitive materialsr the lor.gitudinal and transverse cuts are made by a pair of scissor-like cutters.
As a ,uriher alternative, the transverse cut ~an be - made by a heated roller which is moved upwardly into contact with the bag at or.e of i~s sices, and then moved swiftly - across the width o' the bag.
In a presently pre erred embodiment of the appa-ratus, each bag to be em?tied is conveyed into the machine by an intermittently operated belt conveyor, which projects -7.

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through an opening at an end of the machine and drops the bags one at a time, as they lie on one of their larger faces on the conveyor, on to a hinged and dropable vibrator table on which the bag is centered and its contents compacted by vibration. Centering of the bag on the table is effected first in the longitudinal direc~ion by laterally inward movement of a parallel pair of oppositely disposed, transversely extending heated straight edge cutters between which the bag is sltùated and which ~Jill produce the transversely extending 10 cuts on the forward and rearward end edges of the bag, about 1" or 1 1/2" above the downwardly facing bag face. As this longitudinal centering of the bag is completed, and momentarily before the transverse cuts are made, a flat clamping plate .
engages the upwardly facing wall of the bag, pressing the bag and its c~ntents against the vibrator table, thus squaring and holding the ~ag to ensure that "clean" cuts are made by the -'ransverse cutte~s which then press into the bag mo~entarily from opposite directions.
After the pair of oppositely disposed transverse 20 cuts are made the trarsverse cut.ers are backed away, the gripping plate is raised, and a heated, longitudinally extending straight edge cutter and a parallel, oppositely disposed longitudinal perforator are ~.oved concurrently and laterally in opposite directions into contact with the respective longi-tudinal side edges of the bag, first to center it in the transverse direction whereupon a spiked gripping head now pierces and grips the upwardly facing bag face, and tken to simultaneously cut one longitudinal edge between the previous transverse cuts and perforate the other longitudinal edge - 30 to form a line of perforations between the previous transver~
cuts, thus forming a hinged, U-shaped flap of the downwardly facing bag wall.

10~0~55 ~ ile th~ ba~ continues to be gripped by the si~iked gripping head, t11e vibrator table is pivoted 90 down~lardly to permit the bay flap to ope~ and the bag contents to fall into a discharge chute or hopper therebelow. A short burst of compressed air through a plurality of air nozzles, inter-spersed with the gripping head s~ikes, ensures complete emptying of the bag contents.
Return of the pivoted table to its horizontal posi-tion preceded by further down~-ard movement of the gripping head sandwiches and compacts the bag between the two and readies the empty bag for discharge.
Discharge of the bag is effected laterally to the side of the machine by first raising and then tilting the gripping head which holds th~ empty bag. A "stripping" move-ment of the gripping head, by which the aforementioned clamping plate is again moved to a position below and thus concealing the bag gripping spikes, strips the empty bag from the tiltéd head and into a bag discharge chute for gravity removal from the machine.
The gripping head is then returned to its vertical position with its clamping plate properly disposed for pressure-clamping of the next filled bag during the transverse cutting - thereof, as previously described.
These and other objects, features and adYantages of the invention will be more fully understood from the follo~ing detailed description, when read in conjunction with the several figures of the accompanying drawings.
- Figure 1 is a side view of bag opening and emptying apparatus according to one embodiment of the invention, with 30 certain parts cut away and with bag positions shown in dashed lines;

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Figure 2 is a view in perspective of a typic~l full bag which will be opened and emptied using the apparatus;
Figure 3 is a somewhat schematic side view of the apparatus of Figure l;
Figure 4 is a v~ew in section taken along line 4-4 of Pigure 3 and looking in the direction of the arrows;
Figure 5 is a vie~ si~ilar to Figure 4 but with the means for squaring and-flattening a bag in operation;
Figure 6 is a view sLmilar to a portion of Pigure 3 in the co~dition of Figure 5;
Pigure 7 shows the apparatus of Figure 3 at a step of the bag opening operation following that of Figure 6;
Figure 8 is a view in section taken along line 8-8 of Figure 7 and showing the action of longitudinal cutting wheels in the apparatus of Figure l;
Figure 9 is a view similar to that of Figure 3 at a stage at which longitudinal cutting has been completed but the crcss cut has not been made:
- - Figure 10 is a side view of the bag emptying station 20 of the apparatus of Figure 1 at a condition immediately after that of Figure 9;
Figure 11 is a view toward the front end of a bag in .the condtiion of Figure 9;
Figure 12 is a view similar to that of Figure 11, but in the condition of Figure 10;
~ Figure 13 is a view similar to that of Figure 10 bu.
at a subsequent step of operation of the apparatus of Figure 1 at which the bag has been picked up for emptying;
Figure la shows the condition of the apparatus o ` 30 Figures 10 and 13 after a bag has been emptied;
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~o~o~j~.'3 ~ i~ure 15 shows the manncr in ~Jhich a bag opens for e~ptying in accord~.ncc with the embodiment of the invention sho~n in Figure l;
Figure 16 is a vie~ similar to that of Figure 11 ~lit~
the bag discharging mechanis~ in operation;.
Pigure 17 is an overall view from above of the appa-ratus of Figure l;
Figure 18 is an erlarged additional side elevation, partially broken away, sno-Y~ins the infeed end of the apparatus 10 of Figure 17;
Figure 19 is a view in section taken along line 19-19 of Figure 18 and looking in the direction of the arrows;
Figure 20 is a view in section taken aiong line 20-20 of Figure l and looking in the direction of the arrows;
Figure 21 is a sectional view taken along line 21-21 .
of Figure 20 and looking in .he direction of the arrows;
- Figure 22 is a detail view of the area encircled in Figure 17 with shadow lines indicating two positions of movable parts;
Figure 23 is a sectional view of longitudinal cutters - according to one embodiment of the invention, showing their relation to a bag being cut;
Figure 24 is a side view of a rotary transverse cut-ting arrangement according to one em~odiment of the invention;
Figure 25 is a plan view of the cutting arranger.~ent o~ Figure 24;
Figure 26 is a de.ail vie~J of a baffle arrangen~ent used in the arrangement of Figures 24 and 25;
Figure 27 is a sectional view along line 27-2~ of 30 Figure 24 and looking in the direction of the arrows;
Figure 28 is a view in section taken along line 2~-28 of Figure 27 and looking in the direction of the arrows;

Figure 29 is a detail view in perspective of a lin'~.
element shown in Figures 27 and 28;
Figure 30 is a view from the side, partially in section, of an empty bag discharge mechanism of the apparatus of Figure l;
Figure 31 is a view in section taken along line 31-31 of Figure 30 and looking in the direction of the arrows;
Figure 32 is a detail view of a locking device of the bag lifing head of the P.igure 1 appara.us; :
-10 Figure 33 is an end view in section of the bag lifting head incorporated in the apparatus of Figure l;
Figure 34 is a vie~ similar to that of Figure 33 . but with a bag engaged by spikes of the lifting head;
Figure 35 is a view in section taken along line 35-35 of Figure 34 but with the bag not shown for the sake of clarity;
Figure 36 is a top view, partially in section, of an - end-stop sensing mechanism incorporated in the Figure 1 apparatus;
- Figure 37 is a side view, with parts removed for .
clarity, of the end-stop sensing mechanism of Figure 36;
Figure 38 is a view in section taken along line 38-38 of Figure 37 and looking in the direction of the arrows;
Figure 39 is a view in section taken along line 39-39 of ~igure 37 and looking in the direction of the arrows;
~ Figure 40 is a view in section taken along line 40-40 .. ~ of Figure-37 and looking in the direction of the arrows;
Figure 41 is a view in section taken along lines 41-41 of Figure 37 and looking in the direction of the arrows;
Figure 42 is a side view, with portions broken away, of a transverse bag cutting device according to the invention, showing the operative portion of a blade in dashed lines;
Figure 43 is an end view in elevation of the cutting device of Fiqure 42, partially broken away;

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Figure ~.~ is a de ~2il vie~ OL an alternative form of cutter of the invention;
Figure 45 is a frag~en'ed side vie~ of a bag opening and emptying apparatus acco~dir.g to ano.her, preferred embodi-ment of the invention, with cer,ain parts cut awa~ and with bag positions sho-~m in dashe~ lires;
Figure 46 is ar. end elevational vie~l taken along line 46-46 of Figure 45, and illustrating certain features of the operation of the apparatus;
~igure 47 is a perspecti~e view from the underside of a typical full bag which will be opened and emptied using the apparatus of Figure 45;
Figure 48 is a fragmented side view of a portion of the apparatus as shotm in Figure ~5, but in a different posi-tion during operation;
~igures 49-52, inclusive, are fragmentary end views of the paxts emphasized in Fisure 48 which, together with ` Figure 48, show their sequence of operation;
Figu~es 53-and 54 are additional end view sho~7ings 20 of the apparatus ol Figures 45-~8, sho~Jing further sequences of operation;
Figure 55 is an enlarged perspective view of a segmented-blade type cutter ~roYding a straight cutting edge;
Figure 56 is a fragm.en.ea perspective view similar ; to Figure 55 showing an alternative, preferred segmen.ed type straight edge cutter, in which eacn blade segment has scalloped configuration;
Figure 57 is a further enlarged cross-sectional end view as seen from line 57-57 in Fisure 55;
Figure 58 is an enlarged perspective showing ol a hinge line perforator bar as is a feature of the apparatus of Figure 45;
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Figure 59 is a furthcr enlarged cross-sectional end view of the pe_for~tor bar as seen from line 59-59 in ¦ ~igure 58 DETI~ILED l)E:SCE~IPTIO~ O~ E~130DI~ iTS OF THE INVE~TION:

` The some~ha. sim~liCied overall view of Figure 1 illustrates apparatus in accordznce with one embodiment of the invention. In Figures 1-~4 the bags whose contents are being removed are generally designa~ed by the reference char-acter "B". Such bags B are sho~m in three stages of the bag 10 opening process at B1, B2, B3 in Figure 1. The bag at Bl has - just entered the apparatus-of the invention from a supply of full bags. The bag B2 is at a stage where the bag and its contents are sha~en and "squared" so that it is uniformly presented for opening and emptying as is necessary for best opera~ion. The bag at B3 has been cut in one direction and is at a second cutting posi.ion, where, after thé second cut-ting, its contents are removed. From its position at B3, after emptying, the bag B will be discharged from the apparatus and collected with other empty bags.
As shown in Figure 1, the various bag processing mechanisms of ~he invention are supported by a sturdy struc-tural frame including overhead frame structure 11, vertical beams 12, lower transverse fr~me structure 13, and a plurality of supporting posts 1~. The particular structural frame construction shown in Figure 1 is merely illustrative of a typical installation of the apparatus and can be varied to suit the requirements of the building wherein the apparatus is to ~e installed. It will be noted, however, that the frame structure shown lends itself to enclosure of the apparatus to 30 isolate the apparatus from the environment as a closed system.

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~lt~nou~Jh not illustrclt~l, it will be unclcrstood that appro-priate, dustproo~ p~nelins is mount~d on tne frame structures 11, 12 and 13 for the purpose.
The bags enter from the left in Figure 1 through a normally closed door lS sno~,~ in its open position with i-ts ertical actuating cylinder 16 in retracted condition. After a bag has passed through the door~Jay of the door 15 ihe cylinder 16 pushes the door up to a closed position. After passing through the door 15 the ba~ at Bl travels forward and down a roller conveyor generally designated 17 and falls off the con-10 veyor 17, landing on a table at 18 and impacting a cushionedstop gate 24, thus flattening and squaring the front of the 1 bag for cutting. Additional preparation for cutting will be I described hereinafter.
Located beneath the conveyor 17 is a long cylinder 20, the piston 21 of which se~ves to push each successive bag B forward along the table 18. A top plate 22 flattens the upper side o~ the bag at B2. A piston and cylinder assembly 23 raises and lowers the top plate 22 for entry of the bags B
and is later raised after the bag has been moved from table 20 18. The leading end of the bag at B~ can be seen to be ini-tially restrained from forward motion by the retractable stop gate mechanism 24, which functions immediately after impact by the bag. While the bag rests at B2, vibrating means shake down the bag contents and other squaring means to be described hereinafter cooperate with the top plate 22 to form the suc-cessive bags into uniform sguarea shape for opening, the bag front ends having been squared by the stop gate 24.
After shaping and squaring, each bag is urged for-ward by the piston 21 to the position sho~n at B3, while passing 30 under a free rolling or powered pinch roll 25 and between longitudinal free rolling heated cutters 28.

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At B3, a bag cngaging head assembly generally desig-nated 26 is lowercd into bag holding position, where the head 26 holds up the bag by ~echanical engagement with the bag's upwardly facing side surface. A piston and cylinder activating mechanism for raising and lowering the head 26 is shown at 27.
Under the bag at B3 is a hopper H for receiving the bag contents when the bag has been opened by cuts at its lower side edges, join.ed by a transverse cut. A longitudinal cutter 28 and one form of transverse cutter 29 are shown in Figure 1 10 and will be described in greater detail in conjunction with more detailed figures of the drawing. It will only be noted here that in several embodiments of the invention sho~m, these cutters are heated to open cuts through the bag walls by a combination of heat and pressure. The hot cutting edges of the bag cutters are heated to a temperature of from about 800F.
to about 1000F., preferably to a temperature within the range of 850-900F., for cutting the bag without igniting the bag or its contents.
During cutting, a table 30 supports the bag at B3.
20 This table 30 comprises a pair of hinged door parts 31, 32, mounted for pivotal movement to the positions shown by dashed lines in Figure 1 so that the bag contents can drop into the hopper H after cuts have opened the lower side of the bag B.
Cylinder and piston mechanisms generally designated 33 and 34 operate the trap doors 31, 32. Full 90 movement of the door parts 31, 32 assure complete emptying of the bag contents.
Means not sho~m in Fisure 1 then remove the emptied bag from the position at B3 and the next bag is pushed into position for opening.
Figure 2 shows a t~pical bag B of the kind that can - be very effectively handled by the method and apparatus of the 10~
invention. I~ will be seen that the full bag B of Figure 2 has general form of a parallelipiped of so~ewhat rounded contours with a generally rec,angular down-;lardly facing side face 40 and,lo-er longitudinal edges 41. Industrial and com-mercial bacs of this type used for storage and shipment of bulk goods c3enerally range in size from about 3" by 14" by 20" to about 12" by 28" by 48", and the various parts of the apparatus described are suitably proportioned to accommodate bays of this rane of sizes, though of course the apparatus 10 could be of greater or smaller dimensions for particular applications.
Before discussing the details of the various mechan-isms and devices employed in the apparatus of the invention, reference is made to the schematic illustrations of Figures 3-16 which illustrate the process of the invention in the step-by-step handling of a single bag B. --? In F~gure 3, the bag at B2 has arrived at the tabie 18 after entering through the door 15 and passing dot~n the roller conveyor 17 as indicated by the bag Bl shown in dashed 20 lines. It will be seen that the door 15 has been returned to its upper, closed, position under actuation by the piston . . .
16 and-that another bag Bo is waiting at the door 15 for admission when the door 15 opens again. The long piston 21 is retracted within its cylinder 20 and the bag at B2 has its forward end abutting the gate 24, which is in its raised posi-tion. A vibrator is mounted on the underside of the tube 18 as indicated to vibrzte the table for shaking down the contents of the bag at B2. Above the bag at B2, at its elevated posi-tion, a bDp plate 22 is shot;n with a pinch roll 25 mounted 30 for movement with the top plate 22 upon extension of the piston 23.

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~ hca~ of the position of the bag B2 the table 30, with its hinged doors 31 ~Ird 32, ~waits the entry of a bag.
The bag engaging head 26 is in its raised inoperative position.
Tt can be seen that the head 26 has a plurality (five are sho,m as typical) of trans~Jersely oriented elongated modules 45 interconnected Vi2 a lonsitudinally extending me~ber 46 and carrying spiXe means for supporting a baa by engaging its upper side face. Dot~mwarcl~r poin~ing hollow spikes 47, communicating ~ith an air line as indicated, are provided for forcing air 10 under pressure into a bag to aid in removal of the bag contents when the bag has been cut open.
- ~igures e ar.d 5 show the action of the flattening and squaring device at the vibrating table 18. In Figure 4 the bag is shown in the condition it has in Figure 3 before the s~uaring operation. Side squaring guides 50 are elongated ~embers aligned parallel to the direction of travel of the bag B. As shown in Figure 5, these s~uaring guides 50 move trans-versely inward to squeeze in against the vertical sides of the bag, after which the top plate 22 descends and flattens the - 20 top of bag B and the vibrator shakes the bag contents to fill the bag corners and settle the contents fully.
Figure 6 illustrates the bag B in the squared con-dition that results from the action of the side sauaring guides 50 and top plate 22. It will be noted that in Figure 6 the stop gate 24 has been lowered by the retraction of a vertically disposed piston 52 into its cylinder 53, this piston 52 being shown extended in Figure 3. The pinch roll 25 is now in position to engage the bag B when piston 21 pushes the bag forward, since the lo~;ermost position of the surface of the 30 roll 25 is slightly below the level of the top plate 22 that carries the roll 25.

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l`he succeeding stage of the process is shown in ~igure 7, wherein the ~iston has begun to push the bag for-ward to the cutting table 30. The longitudinal cutting devices 28 have begun to cut leng,hwise along the side edges of the bag B as it passes be,ween the~, restrained agains~ upward ~otion by the spring loaded pinch roll 25. The final forward position of the bag is shown by dashe~ lines in Figure 7. ~hen the bag has reached the location indicated in dashed lines it contacts a back stop sensor device senerally designated 55 and the head 26 moves down and engages the bag.
Figure 8 shows the longitudinal cutters 28 in action, I cutting open the bag along Its lower side edges. Piston and ¦ cylinder means 56 restraining the cutters 28 so that they exert I cutting pressure against the bag appear in Figure 8.
! It will be understood that by the time the bag has ¦ reached the position indicated in Figure 9, the whole length of the bag has passed .he position of the longitudinal cutters, the bag having been pushed forward by the eY.tension of the , piston 21, w~ich is then re.racted as shown by the arrow.

! 20 ~t this stage, the transverse bag cutter 29 is ready to produce a cross cut joining the two longitudinal cuts.
i ~he head 26 is in its lowered position in Figure 9, to impale - the bag on its spikes and ready to support the bag when the table doors 31, 32 open to spill the contents of the bag into the hopper Y.. It will also be seen that the piston 21 has been withdrawn at the stage shown in Figure 9, ready to engage and push forward a next bag for squaring, opening and emptying of the contents. The top plate 22 has been raised to allow a following bag to enter on to the table 18 30 and the stop gate 24 has been raised.

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The hacJ emptying operatic)n can be ~xplain~d ~ith re.erence to Pic;ures 10-12,in ~hich Figure 10 sho~s a cut bag B ready to discharye its co~tents upon lotlering of the trap doors 31, 32. The viet~s o~ Figures 11 and 12, taken at a right angle to that of Figure 10 ar!d rear~Jard along the direction of travel of a bag to the c~t~ing table 30, show ho.7 one form o.
transverse cutter 29 rollo-~s a segmented "garage door" middle section 60 of the table 30 across the 7idth of the bag whe.
the "garage door" is activa,ed by a cylinder and piston 61.
10 In Fisure 11 the cross cutter 29 has not yet begun to traverse the bag and in Figure 12 the cut has been com21etea.
In a pxeferred e~bodiment of the invention, the garage door and xotary cutter arrangement is replaced by an elongated heated knife to be described hereinafter in con-junction with certain fisures of the drawin~, but for so~e applications the rotary transverse cutter 29 may be advan-` tageously ~ployed.
The emptyins of the bag r upon pivotal opening ofthe trap doors 31, 32, is sho-~m in Fiyure 13. The bag B, now 20 cut open, is supported by mear.s carried by the head 26 while horizontally directed air blo-~m through holes in the sides of the air spikes 47 gently loosens contents adhering to the bag ir.terior surfaces and fills tne vo~d left as the contents move downward into the hopper H by gravity. After emptying the bag the space bet~leen the doors 31, 32 is closed again.
At the stage sho~m in ~igure 14, the head 26 has been lifted up from its position during emptying of the bag, prep-aratory to the discharge o' the empty bag. This occurs simultaneously ~Jith the start of door closing and shutoff o' 30 the flo~J of air through the air spi~es 47.

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~ igur~ 15 illustrates a prcf~rr~d manncr of cutting open a bag using an ~I-shaped pattern of cuts, two longitudinal cuts L produced by the cutters 28 and one transverse cut C
produced by the cross cutter 29, allowing the bag's lower face to open out downwardly as a pair of flaps shown in dashed lines.
In a modified form of the invention, the transverse cut C could be made at one end of the bag B, joining ~he cuts L to form a U-shaped array and allowing the bottom of a bag B to open as one large flap. Full opening of the bag prevents any obstruc-10 tion to the downward fall of the contents. In either case, thebags can be efficiently removed by means of the mechanism schematically shown in Figure 16.
As shown in Figure 16, after a bag has been emptied and the head 26 has been raised to its elevated position, the empty bag is fed to a disposal chute 65. Bag holding means to be described in greater detail in conjunction with other figures of the drawing are associated with the head 26 to engage the empty bag. A hingedly mounted plate 66, operated by a piston 67, swings up under the side of the bag and holds 20 the empty bag against a large roller device 68. This roller device 68 pushes the bag between cooperating rollers 69, 70 to flatten and feed the bag down the chute 65 upon disengage-ment of the bag holding means of the head 26. The plate 66 is then lowered and the cycle is ended.
Although the foregoing discussion has generally described apparatus in conjunction with the steps of the bag -~ opening and emptying process of the invention, a more detailed description of various cooperating systems and mechanisms of embodiments of apparatus according to the invention will now 30 be presented, with particular reference to figures 1 and 17-44.

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l`h~ ov~ra]l n~c~n Vi~t~ of ~i~ULC 17, in which cert~in parts have been cut at~y and in which som~ hidd~n parts are sho~n in dashed lines, can b~ consid~r~d in conjunction ~ith the side view of Figure 1 to sho~ the relative positions of the various mechanisms depicted in Figures 18-44. Thus the entrance door 15 is sho,n at the far left in Figures 1 and 17, and the bag engagir.g hea 26 at the right hand side of the drawing.
The rela,iorship of the entrance door 15, its actua-ting cylinder 16, the conveyor 17 and the long cylinder 20 is illustrated in greater detail in Figure 18. The door 15 has the form of a generally rectangular, vertically disposed panel 75 with an upper end portion 76 bent at a substantially right - angle in the direction of entry of a bag. This upper portion 76 of the door 15, and/or the upper frame member of the doorway ~not shown) can be sultably padded to prevent possible injury to wor~men's hands when the door closes. The generally verti-cally mounted door actua,ing cylinder 16 has its piston 77 pivotally secured at its upper end to the door panel 75 below the bent portion 76, for pushing the door upward to its closed position. A bracket 78 having a slot 79 for sliding adjustment of the position of the conveyor 17 holds 2 pin 80 secured beneath the rear erd of the conveyor 17. Although only one side is seen in Figure i8, it will be understood that a like moun~ing arrangement is provided at the other side of the conveyor 17.
The conveyor 17 has elongated side rails 83, in which are journalled the shafts 8k of a plurality of equally spaced - rollers 85 for conveying the bag down after it passes the door 15. At its forward end the conveyor 17 is mounted on the 30 structural frame by bracket means ~6. The arrangement shown is a yravity rollir.g arrangement, although any gravity chute having low friction could be used.

~ en~ath the conveyor 17, and firmly secur~d to an upright structur~l fr~m~ ~e~ber 12 by me~ns of an angle me~er 91, is the long cylinder 20 of the bag pushiny piston 21. Since the piston 21 serves to push ~ bag B through the apparatus to the positions where the bag is opened it will be understood th2t the cylinder 20 is o~ consicerable length. The for~7ard end 92 of the cylinder 20 is also fir~ly secured to structural main fr~e mem~ers. The piston 21 is sho-Jn in its retracted pOSition in Figure 18, with a thrust plate 94 mounted on the forward end of the piston 21 just beneath the forward end of the roller con-veyor 17. The thrust plate 94 has a generally rectangular front surface 95 extending across the width of the apparatus suffi-ciently to engage the rear end face of a bag ana thrust the bag forward. Because of the considerable length of its stroke, the piston 21 is provided with support by rollers 96 mounted for rotation at the bottom of the thrust plate 94.
The table 18 shown at the right in Figure 18 is mounted for vibratory motion with respect to the frame structure so that the contents of a bag resting on the table can be shaken 20 and settled into the squared shape most suitable for the cutting -- operation to follow. Above the table 18 is seen the rearw~rdly and upwardly directed edge portion 97 of-the top plate 22.
The slanted surface 98 of this slanted part 97 effectively assures that the bag slides under the top plate 22 on its way to the table 18 and stopgate 24. Reference numeral 50 generally indicates one of a pair of side sguaring suides, which guides 50 are positioned at opposite side of the path of travel of a bas along the surface of the table 18. The side squaring guides 50 and the top plate 22 cooperate sequentially to square the - 30 bag and its contents on the table 18 before the bag is cut open.
Ber.eath the table 18 a vibratir,g mechanism, such as an eccen-trically driven device, causes the table to vibrate while the bag ~ 3 I

is being squaL~(I to settle the ~a~f con~ents in all thc bottom volume ~ COLners and edges of th~ b~g.
i The structure and o~eration of the side squaring guidos 50 can be understood more fully by considering Figure 19, ~herein the sq~aring guides 50 are seen to be mounted for la~eral movement to-a~d and a~.ay fro~ each other through an x-like arransement of crossed levers 101 and 102 eY.tending beneath the table. The le~ers 101 ard 102 are pivotally interconnected at their point of intersection 103 and the ends of the levers 101 and 102 have elongated slots 10~, 105 respectively below the in~eed end of the table 18 for sliding engagement with vertically extending rollers 106 maunte~ for movement perpendicular to the direction OL movement of a bag toward the table 18. Both ends of each squaring guide 50 are mounted for movement ~7ith the crossed levers 101, 102 so the sguaring guides 50 are kept mutually parallel as the angle 'or~ed between the levers 101, 102 is decreased to bring the guides 50 closer together, or increased to move the guides apart. When a bag reaches the table 18 the side s~uaring gui~es 50 are activated, move inward and confine the sides of the bag as the bag contents are shaken.
As will appear ~ore fully in connection with drawing figures showing the longitudinal cutting arrangement, cutting devices are mounted for movement with the squaring guides 50 to-insure accurate cutting of bags along their lower side edges.
The top view of ~isure 20 and the side view of Figure 21 illustrate the preferred structure for the bag handling apparatus associated with the squaring operation. In these figures, the top plate assembly 22 is shown to be mounted for - vertical movement into and out of engagement with the upper surface of a bag by means of the piston and cylinder assembly 23. As shown in ~igure 20, the top-plate 110 is a generally - flat sheet. ~he assembly 22 includes a sturdy fra~e of lon~itudinal m~mbers 111, side fr~me el~ents 112 and a cro;s be~ 113 above the top plat~ 110 and resilient material such as rubber is interposed bet-.;een this frame structure and the plate 110. The lower end 114 of the piston 115 of the actua-ting cylinder assembly 23 iS secured to the cross beam 112 by a clevis fittins 116. ~or s~ooth up and do~n movement, a roller guide arranaement i 5 provided. Four vertically disposed cylindrical roller suides 117 are provided adjacen, the four corners of the top plate 22. These roller guides -10 117 can be secured to the frame structure of the machine as shown in Figure 21. At the bag entry end of the top plato 22 the roller guides 117 cooperate with pairs of spool-shaped rollers 118 carried by upright members 121 secured to the side frame members 112 of the top plate 22, and spring-loaded by spring ~eans 122 to keep the rollers 118 in contact with the guides 117.- Generally, no such spring means are needed for - - the rollers 123 carried by uprights 124 at the downstream era of the top plate 22.
~ igures 20 and 21 also show the pinch roll, generally 20 designated b~; ~eference n~meral 25 in Figure 1 and elsewhere.
In the preferred embodiment of the invention, the pinch roll 25 is not a simple cylinder, but has a more advantageous -structure for best xesults in its action of backing up bags during longitudinal cutting while aiding in feeding bags through the cpparatus. The roll 25 is preferably free roiling but may be driven by a motor (not shown in Figures 20 and 21) to ~ge the bag along.
As shown in Figure 20, the pinch roll 25 has a central - horizontally ~isposed shaft 130 journalled at its ends 131 in 30 housings 132 with appropriate bearings for smooth rotation.
Spr~ng loading means 133 are provided as sho~m in ~igure 21.
- The housings 132 are supported by frame means 134 firmly secured to structural me,~bers of tne top plate asse~bly 22.

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cylindrical dr~m 135 mounted on the ;haft: for ro~.ltion thercwith ~ls a larger dia~eter at its end portions 136 than at its middle section 137. It h~s been found that by providing a so~ewhat resilient surface at the middle of the roll 25, pressure at the center of the bag can be advantageously reduced, and for this purpose, rings 138, preferably of foa~
rubber, extending around the roll 25 at its middle section 137 are employed.
- Figure 21 shows the top plate 110 and the pinch xoll 25 in lowered condition with a bag B emerging from beneath the roll 25. The stop gate 24 is shown in dashed lines in its open, or lowered position. It will also be noted that the pinch roll 25 is positioned just ahead of the longitudinal cut.er 28, whereby the bag B is pressed between the roll 25 and the cutter 28 for effective cutting action as the bag is pushea past the cutter 28.
In the description of the cross levers 101, 102 and side souaring guides 50 shown in Figure 19 it was explained that ~ i at their rorwaxd ends the squaring guides S0 are also mounted 20 for move~ent with the cross levers 101, 102. This is shown in Figure 22 which also illustrates how the longitudinal cutters 28 are moved with the squaring guides 50. Figure 22 is a vie~7 in detail as in~icated by the circled area in Pigure 17. The squaring guide 50 is shown to be secured to a carriage 141 mounted to move horizontally and perpendicular to the length -of the squaring guide 50. The carriage 141 is shown to be generally box-like and to have four spool-like rollers 142 arranged at its corners to roll along a pair of txansversely extending cylindrical tracks 143, 144, which tracks are secured 30 to the machine fra~e structure. Cooperating lower rollers 145, 146 can be best seen in Figure 23. The carriage 141 also carries a vertically disposed roll~r 150, simil.lr to the rollers 1~6 of Fi~ure 19, riding in a slot 151 at the ~or~Jaru end of the cross lever 102. Lateral movement of the carriage 141 carries the cross lever 102 along as indicated by the dashed line showing of two positions of the cross lever 102 in Figure 22. A symmetrical arrangement is provided at the opposite side of the machine from that shown in Figure

2~, so that when the side squaring guide 50 and lever 102 are moved to the left and clockwise respectively, in Figure 22, the other cross lever 101 moves toward the right and counter-clockwise because of the scissor-like pivoted connection of the cross levers 101, 102. A pneumatically operated piston 152 of the piston and cylinder assembly 56 secured to the carriage 141 serves to move the carriage 141. The stop gate 24 and its vertically oriented actuating piston 153 as well as a sturdy hinge 156 of the door 31 are also seen in Figure 22.
The longitudinal cutters 28 are shown in greater detail in Figure 23, wherein a bag B is seen in the process of having cuts made at its lower side edges 41 as the bag passes 20 benezth the pinch roll 25. Both cutters 28 are mounted for move~ent in carriages 141 as shown in Figure 22, and are oriented a~ essentially 45 degree angles with respect to vertical to best engage the bag B for longitudinal cutting.
This cutting is done by heated cutting wheels 159. Each wheel lS9 has a cylindrical body 160 with a protruding central annular cutting edge 161. The wheels 159 are mounted on axles 162 journalled in a block 163 that is generally U-shaped in cross section as shown. The block 163 is itself slidably mounted in a mating recess 164 of the carriage 141 and the 30 bloc~s 163 carrying the cutting wheels 159 are urged to~lard the bag by positive bias spring assemblies 165 and 166. The cutting wheel 159 is heated by electrical resistance heating coils within the cutter body 160 and not illustrated. A
flexible line 167 carries electrical wires to provide power for heating and another ~lexible line 168 carries cooling air to channels provided within the block 163. The cutting wheels 159 are not driven ~ut roll freely against the bag B as the bag is pushed past by the piston 21. A combination of heat and pressure neatly and cleanly cuts the bag. Free rotation and spring loading of the cutters ensures continual contact 10 with uneven bag surfaces for a complete, unbroken cutting action.
As prevlously indicated the cutting edges are heated to a temperature between 800F. and 1000F. and preferably about 850-900F. to cut the bag wall material without ignition of the bag contents. To achieve most effective cutting it ha~
been found that the cutting edge needs to contact the bag at any given area for less than one second and that contact for about 0.4 seconds is very effective. This can be accom-plished by moving the bag for~rard at about 1 to 1.5 feet per second. --The cross cut that joins the longitudinal cuts to open the b~g B can be made by a transverse cutting whe~l device 29 as shown in Figure 24. The transverse cutter 29 has a heated cutting wheel 169 mounted to rotate freely in a housing block 169a A pneumatic piston and cylinder assembly 171 is provided for raising the cutting wheel 169 into cutting position as shown in Figure 24 and lowering the cutting wheel into a retracted position out of contact ~tith the bag when not cutting. This piston ard cylinder assembly 171 is mounted for movement with the housing block 169a of the cutter 29 to move across beneath the bag during cutting. The tran~verse cutter housing block 169a has rollers 172 at its four corr.ers riding on rails 173. ~hen the doors 31 and 32 that su~port 28.

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the bag during cutting ~re in the horizontal position shown in Figures 24 and 25, fur.~er rails 174 mounted beneath the leading edges of the doors 31, 32 meet end-to-end with the rails 173 to provide a continuous track, and as sho m in Figure 27, rails 175 on the opposite side of the machine provide a further extenslor of tho trac~ for the transverse cutter 29.
The doors 31 and 32 have hinges 156 for pivoting downward through a full 90 cegrees. To lock the doors 31 and - 32 in their closed, horizontal position, pistons 176 are moun.ed 10 in pneumatic cylinders 177 for extension as bolts into fittings 178 provided beneath the doors 31 and 32 as shown in Figure 25. When these bolts~ 176 are extended and the doors 31, 32 are locked in place, the ~racks 173 and 174 are aligned.
Four cylinders 177 are preferably employed, one cylinder 177 at each side of each of the doors 31 and 32.
As shown in ~igure 26, the wheel 167 has a cutting edge 182 protruding from a generally cylindrical body 183, and can be raised or lowered as indicated to bring the edge 182 into and out of bag cutting position. The lower, retracted 20 position of the outting wheel body 183 is shown in dashed lines and the extended position in solid lines in Figure 26.
Pivotally mounted baffles 184 rest on the surface of the wheel body 183 and these baffles are linked by levers 185 to the housing block 169a so that they follow the movement of tne cutting wheel 169. The bafLles 184 close the space around the cutter body 183 except at the edge 182 and thus prevent catching of a cut or damaged bag in the cutter housing or frame.

lV~;5g Reference is now rade to Figures 27-29, sho~ing a "garage door" arr~ngement for closing the space between the hinged doors 31 and 32 ~t the line of passage of the trans-verse cutter 29. Figure 27 is a view in section taken at the line of passage of the cutter 29 and looking back~ard down the path of travel of a bas ~ to the cutting table 30. The transverse cutter 29 is sho-~ in dashed lines at its starting position at the right of the table 30 in Figure 27 with its roller wheels 172 on the rail 175. In the starting position 10 the transverse cutter 29 is guarded by a housing 186. It will be understood that the-transverse cutter 29 is brought to this starting position with its cutting ~Iheel 169 retracted by traversing the rail section 174 beneath the closed doors 31, 32.
At the left in Figure 27 there is a generally ver.i-cally disposed cylinder 187, pivotally mounted at its lower end 188 to permit some tilting motion. The piston 189 of the - cylinder 187 can move from the retracted to the extended posi-tions shown in Figure 27 to draw the transverse cutter 29 ~rom 20 right to left and, upon retraction, push the transverse cutter back to the left side of the table 30. The means connecting the piston 189 with the cutters 29 also serves to close the space between the doors 31, 32. In the preferred embodiment - of the in~ention shown, a large n~mber of seal plates i92, one of which is shown in Figure 29, are pivotally connected ena to end by means of pins 193 passing through aligned inner an~
outer ears 194, 195 projecting perpendicularly from the body 196 of each plate. The pins 193 carry small roller wheels lg7 to ride on the rails 173, 174,and the belt-like assembly of 30 interconnected seal plates can roll like a garage door. The seal plate 192 farthest from the trans~erse cutter 29 is 30.

hing~clly conl~ec~ed to thc upper end of the piston 1~9 by means 198 best shown in Fi~. 28.
Returning to Fig. 27, it can be seen that the track formed by the rails 173, 174, 175 has a curved and then upwardly directed extension 201 formed by rails 202 at the same side of the table 30 as the piston 189. Extending motion of the piston 189 thus pulls the whole row of hingedly connected seal plates 192, with the wheels 197 guided by the rails 202, up the track section 201. The seal plate 192 that is last in line from the top is hingedly secured to the transverse cutter 29 so the cutter follows the plates 192 a,cross the table 30 when the piston 189 is extended. Of course, when the cutter 29 is at the right in Fig. 27, with the doors 31 and 32 closed, the seal plates 192 close the gap between the doors 31 and 32.
If there is ample space, a simple sliding panel can - be used in place of the flexible arrangement of plates 192, and a piston and cylinder oriented in the horizontal place can be used in place of the cylinder and piston 187, 189, but the use of the "garage door" arrangement conserves horizontal or ~floor"
space very effectively.
, In one form of the invention employing a different kind of transverse cutter, the "garage door" arrangement is not necessary. This modified embodiment will be discussed hereafter.
Fig. 30 shows the apparatus for lif~ing a bag and re-moving empty bags from the area of the cuttting table 30. More detailed views in Figs. 31-35 serve to show the various co-operating parts. The bag lifting head 26 and its elevating piston are shown at the left in Fig. 30, and the opposed empty bag disposal rolls 69, 70 and bag disposal chute 65 èarlier referred to with reference to Fig. 16 are seen at the r1ght side of Fig. 30.

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Before discussing th~ ba~ tinc~ head 26, the e-npty bag re~oval arrangem2nt, which can be ~ffectively used with bag lifting heads of other ~inds, should be considered.
Empty bags are removed in a direction substantially perpi~ndicular to the ~ath cf tr~vel of full bags through the s~uaring and cutting apparatus. Comparison of Fig. 30 with Fig. 17 shows that th2 main drive roller 68 of the bag removal apparatus is in driving contact with a plurality (four shown) - of cushiored take out rolls 206 coaxially mounted for rotation 10 with a shaft 207. A motor 208 is located at one ena of the drive roller 68 for driving the roller 68. The drive roller 68 is mounted rotatably on the machine frame with conventional bearings 210 at its ends.
As shown in ~ig.- 31, the bag engaging head assembly has a plurality of transverse trough-like modules 45 extending like ribs from a backbone formed by a longitudinal member 46.
The modules 45 are so spaced that the takeout rolls 206 fit between adjacent ones of the modules 45 as best seen in Fig. 1 and 31, when the bag lifting head 26 is in elevated position, 20 for engagement of the empty bas.
The bag B is so held tkat it can be pulled to the right as indicated by the arrows in Fig. 30 by the rolls 206 which contact the bag when the bag is lifted by the head assembly 26 to the position indicated by the dashed lines. The pivotally mounted reaction plate device generally designated by reference numeral 66 cooperates with the rolls 206.
The reaction plate device 66, as shown in Fig. 30, comprises a metal sheet 221 having a downwardly curved lip 222 at its outer edge and a curved central area 223 matching the 30 curvature of the takeout rolls 2Q6 for engaging a bag between the sheet 221 and the rolls 206. The sheet 221 is mounted on

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a sturay frame 224 that is pivotally secured at 225 to the mac~line frame structure. A rod 226 actuated by the piston 67 (shot.~n in Fig. 16) serves to mo~e the reaction plate 66 into position against the rolls 206 when a bag is to be pulled out by the rotation of .he rolls 206. An upper guide plate 227 spaced ~rom the sheet 221 defines a passage for the empty bag to a pair of rolls consisting of an upp_r roll 69 and a lower roll 70, between which rolls 69, 70 the bag is fed to a dis-posal chute 65. The upper roll 69 of the pair 69, 70 is driven 10 by friction contact with the main drive roller 68 as shown.
The lower roll 70 is an idler roll.
To secure a good grip on the empty bags, the rolls 206 and 69 are preferably coated with a somewhat resilient material such as neoprene. The idler roll 70 has, as shot~ at ; 229 in Fig. 30, a fluted surface of foam rubber or other soft material to accom~odate unevenness of the bags. --The array of rolls 206 on the common shaft 207 is supported from the machine frame structure, as generally in-dicated by thedashed lines in Pig. 30. Support and guidance 20 for the bag lifting head 26 is provided by means of guide posts 248 attached to the head 26 and shotm in greater detail in Figs.
31-35.
~ iss. 31~35, when considered in conjunction with Fig. 30, show the preferred structure of the bag lifting head 26. The elongated members 45 carry a large number of spaced, ; downwardly extending spikes 2~7 at positions shot~ in Fig. 31 by small circles. Such spikes, some of which are the hollow air spikes shown in earlier figures with the general reference numeral 47, pierce the upper large wall of a bag and support 30 the bag by mechanical engagemer:t when the bag is lifted upon elevation of the head 26.

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~ `igs. 33--~5 sho-~ th~ spikes 247 to be fir~ly secured to and exte~ding d~n::ard from the members 45 of the head 26.
The members 45 and their generally horizontal frame structure 244 as sho~;n best in Fig. 35 can be called an upper or "gripping"
plate. The spi~es 247 can adv~ntageously be roughened, ridged or knurled to enhance engagement with th2 bag wall.
Beneath the gripping plate assembly 24~, and mounted for limited vertical movem2nt with respect thereto is a lower "stripping" plate asse~bly 245 having channular or trough-like 10 members 245a sized to fit around and beneath the trough-like members 45 of the gripping plate 244 as best shown in Fig. 35.
Apertures 2~6 in the members 245 are located below all of the spikes 247, so that when the plates 244 and 245 are brought together as in Fig. 34, the spikes protrude through the aper-tures 246 to engage a bag as sho~im.
The condition of the head 26 illustrated in Fig. 34 and 35 is produced when the head 26 has descended on to the top of a bag on the table 30 and obtains until the empty bag is stripped from the head as described hereinafter.
After the crosscut has been made and the doors 31 and 32 are opened, the bag contents are emptied into the hopper ~, - aided by horizontally directed blasts of air through air spikes -- 47, which constitute only some of the spikes 247, the others of said spikes serving only as gripping elements.
- The head assembly 26 is then lifted, carrying the empty bag upward totiard the position at which the bag is to be removed as discussed in conjunction with Fig. 30. To effect this removal, the spikes 247 are withdrawn, that is, the bag is stripped off of the spikes 247.

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This stripping is accomplished by li~iting the up~ard movement of the strippingplate 245 while the gripping plate 244 continues to move up~ard. It has been found that the spikes 247 should enter about 1 to 1-1/2 inches into the bag, so the upper plate 244 is allowed to move correspondingly, and equally about 1 to 1-1/2 inches farther up than the lo-Jer plate 245, as shotm in Fiy. 33.
A stop arrangement limits the extent of ~pward movement of the stripping plate. As shown in Yigs. 31-35, there are four 10 ~uide rods 248 passing through fixed guide bushings in a frame attached to the main overhead frame structure. These rods 248 extend upward from the plate 245 through holes 24~a in the upper plate 2~4. An adjustable collar 249 on each rod 248 stops further upward motion upon contact with a stop block 250.
Cooperating with this stop arrangement, there is a latch mechanism 251, shown in detail in Fig. 32, for keeping the plates 244, 245 together during upward movement until the position is reached at which the bag is to be stripped off, and then unlatching to allow t~e upper plate 244 to move up while the lower plate 245 stays in place. Although some other kind of latch could be employed, a very effective type of latch as shown in the drawing comprises a downwardly direc.ed U-shaped me~ber 252 secured to the lower plate 245 to move within a question-mark-shaped element 253 mounted for horizontal motion on the upper plate 244. The element 253 has a step 254 on which the U-shaped member 252 is received when springs 255 urge the question-mark-shaped element 253 horizontally. The horizontal movement of the element 253 under the action of the springs 255 is con-trolled by the interaction of a cam surface 257 with a roller 30 258 mounted on the stop bloc~ 250. Comparison of the positions of these elements in Pigs. 33 and 34 illustrates the action of ¦ the latch mechanism 251.

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Whe~ the spi~es 2~7 ha~e been withdr~;n at the upper limit o~ travel of the bag, the previously described bag removal mechanism of Fig. 30 pulls the e~?ty bag away for disposal.
The construction and function of the side squaring guides 50 has been discussed tYi-;~ reference to ~igs. 1~ and 19 and 22 and 23~ The squaring guides 50 are mounted for inward a~d outt;ard movement t~itn the carriages 141 of the longitudinal cutters 28. On the opposite side of the cutters 28 from the squaring guides 50, there are provided cutting table squaring 10 guides 260 which are also secured to the cutter carriages 141 for inward and outward movement therewith and ~7hich extend as parallel continuations of the guides 50. Fig. 36 illustrates,one of the squaring guides 260 secured by bolts 261 to the carriage 141 (which is not fully sho~in in Fig. 36). The squaring guide 260 shot~n in Fig. 36 houses a back stop sensing mechanism S~
' ~ shown in Figs. 36-41. The other cutting table squaring guide ' 260, which is not illustrated in detail, can be a hollow rail - without internal working parts, since its primary functions are ! to restrain the bag B during .he transverse cutting operation to 20 assure optimum alignment of the back during the cross cutting and to minimize spillage from the longitudinal cuts until the trans-verse cut is completed.
The back stop sensing device generally designated 55 ' serves to indicate that a bag ~ is centered wi~h respect to the transverse cutter 29 so that the cross cut will be maae at the " maddle of the bag.
- The sensor arransement of Figs. 36-41 enables the appa-- ratus to handle bags of varyins sizes by assuring ,that each bag advances to a centered position. For this purpose a paddle-like 30 plate 262 is ~ounted to be pushed by the leading end of the bag while a spring switch 286 is held depressed by the side of the bag. As the plate 262 is pushed forward, the spring switch 286 ~0~ '3 mov~s ~c~ward in the opposite dir~ction until it passes the following end of the bag and is thereby released, ~hereupon the bas is indicated to be in centered position.
A bag is shown in centered position in ~ig. 36, .~herein it can be seen that the pla'e 262 extends inwardly from the guide 260. The plate 262 is mounted on a carriage 263 arranged to roll forward or back along rails 26~, 265 secured lengthwise within the squaring guide 260. Fig. 41 shows one oS the bearings 266 on the carriage 263 for rolling motion along the rail 265.
10 The carriage 263 is secured to both ends of a roller chain 267, and this roller chain passes ovër sprockets 270 and 271 as shown in Figs. 36, 37 and 40. The sprockets 270 and 271 are journalled to roll freely as the roller chain 267 is pulled along by the ; carriage 263. A spring biased intermediate sproc~et 272 is em-ployed to keep the roller chain 267 tight. As shown in ~ig. 40 the sproc~-et 271 is mounted coaxially with a gear 273 ~nich ro-tates with the sprocket 271. The teeth of gear 273 m~sh with the teeth of a similar gear 274 carried on the sa~e shaft as a sprocket 2i5 which is engaged by a roller chain 276. The roller chain 276 20 is similar to the chain 267. The roller chain 276 has both of its ends secured to a carriage 277 mounted for reciprocating motion on rails 278, 279 as shown in Fig. 38. A spring biased chain tensioning sprocket 284, as shown in Pig. 32, similar to sprocket 272, is provided between the sprocket 275 and a further sprocket 285 over which the chain 276 passes. The carriage 277 is thus arranged to move in response to the movement of the plate 262 and carriage 263, but always in the opposite direction.
The carriage 277 carries the spring switch 286 which extends through a slot 287 in the squaring guide 260 towards the 30 bag B. ~en the carriage 277 nas moved bacX to the position shown in Fig. 36, the switch 286 is no longer held inside the guide 260 by the bag, but can pop out at therear of the bag and ooen a Vt~5~
relay g~nerally d~si~nated 288, which, as sho~;n in Pigs. 36 an~l 3~, controls thc ~lot of air through conduits 2~9, 290 This air flow actuates the gripping head 26 to lo~er and engage the bag. The same effect cculd be achieved ~ith this mechanism by employing electrical signals rather than air pressure at the relay switch 288.
Fig. 37 sho~s how, the squaring guide 260 is related to the other parts of the mechanism at the bag cutting area. It will be seen that a V-shaped notch 291 is provided to permit 10 passage of the cutting wheel 169. Notches, no shown, are also provided in the tops of the squaring guides to clear the rows of spil;es 247 of the lifting heàd 26. The hinges 156 of the doors 31 and 32 and the roller wheels 172 and rails 173 are also seen in Fig. 37. It will be noted that a roller wheel 294 is provided at the end of the squaring guide 260 for support as the guide 260 moves in and out.
In applications where the exact position of a bag on the table 30 is not critical, or where all bags to be cut are the same size, the sensing mechanism of Figs. 36-42 can be re-20 placed by a simpler and more economical, yet effective, deviceas shown in Fig. 7. This simpler mechanism consists of a trigger - finger switch 55 mounted on the door 32 at the position which is to be the limit of forward travel of the front end of the bag.
Depression of the switch 55 by the bag end can actuate the other devices as indicated above. The switch 55 could be adjustable to forward or rear positions for handling runs of bags of different sizes.
It has been found that cutting bags open by a combination of heat and pressure, ~.hether by means of freely rotating hot 30 cutting wheels or a dull heated blade avoids the difficulties en-countered when driven circular cutters are used to cut bag ~alls.

iO~0~5'~

¦ ~ut in certain applications of the invention, the longitudinal cutters 28 and transverse cutter 29 can advantageously be re-placed by the self-sharpening scissor type cutter 295 of Fig. 44.
The cutter 295 takes advantage of the relative motion of the bag as tne bag is thrust fort~ard. The same mounting arrangement, i.e. a 45 angle with respect to the bag's lower side edges, can be used for the cutter 29;, and cutters 295 can be positioned at the same location as the longitudinal rotary wheels 28 hereto-fore described. The cutter 295 has a generally horizontally extending 1~ spike 296 with a bag piercing point 297 for impaling the bag as the bag moves forward. This spike 296 is held stationary while a blade 298, hinged to the spike 296 at 299, is rapidly actuated toward and away from the spike 296 by means of a pneumatically or hydraulically actuated piston and cylinder assembly 300, or alternatively, by a suitable electric motion and cam drive. As shown in ~ig. 44, both the spike 296 and the moving blade 298 have sharp edges for cut.ing the bag wall therebetween. In this embo-diment, the cutter 295 is not heated. A similar mechanism for scissor type trans~erse cutting can be substituted for the 20 roller cutter 2g.
A modified form of transverse bag cutter is shown in Figs. 42 and 43. Since the cutter shown in Figs. 42 and 43 is - simpler and less expensive than the rotary cutter 29 that has been - described, this embodiment is preferable in most applications.
This simpler cutting arrangement eli~linates the need for the "garage door" mechanism shown in Figs. 27-29, but in most other structural respects the apparatus is as described above. When the cutter of Figs. 42 and 43 is employed there is no need for engagement of the bag at its sides by the squaring guides during 30 cutting, so these guides can move outwardly before transverse-cutting with the simpler embodiment.

108~ 5~

I~l the embodi~l~n~ of Figs. 42 and 43 a pivotably mounted blade 302 comorising a plurality of blade segments 303 is hinged ben~ath the door 31 so that the cutting edges 304 of the blade segments 303 can he rotated through the space between the doors 31 and 32 to engage and cut the bag by a combination ofheat and pressure at the te~perature stated above for the rotary cutters.
The segmented structure of the blade 302 as best shown in ~ig. 43 allows for ther~al expansion and for self-alignment of the blade segments 303, each of the blade segments being mounted by means of a single retaining screw 314. A plurality of lever arms 305, one for each blade segment 303, are pivotally secured at one end to an elongated rod 306 carried by untins members 307. The members 307 are secured beneath the leading edge of the door 31 as shown a~ 308 in Fig. 42.
~' - At the opposite ends from the rod 306 the lever arms 305 are secured to a rod 309 extending parallel to the rod 306.
The rod 309 is ~.ounted on a piston 310 housed in a cylinder 311 ; and the cylinder 311 is pivotally secured at its rear end to a 20 bracket 312 carried by the door 31. Upon actuation of the piston 310 to forward movement, the blade 302 moves from the retracted - ~ position shown in solid lines in Fig. 42 to the extended, cuttinq -~ position shown in dashed lines in that figure~
; The blade segmRnts 303 are heated by an elongated xod-like heat cartridge 313 that extends through aligned holes in the segments 303. The straight blade edge 304 gives a rapid, - clean cut through the tense, flat bottom of the bag. Bac~up 'orce for the transverse cut is provided by a long crossmember at 245b in Fig. 31 extending across the lifting head stripping 30 frame.

iO~ 5~

The most effective temperature for heated blades as described, whether the blades be rotary or straight, has been found to be about 850 to 900 degrees. The blade members may be of some good heat conducting material such as nickel or a nic~el alloy, and blade cutting edges are preferably chrome coated or plated. To minimize heat loss, particularly radiant, through surfaces of the blade members other than the edges, it has been found that a coating of the refractory material zirconia should be applied to such surfaces. Similar material, like alumina 10 which also has excellent characteristics of low radiant heat emission, can be used. ~
Figures 45-59 illustrate a presently preferred apparatus in accordance with the invention, the apparatus being generally indicated by reference numeral 410. In Figure 45 and other sub-sequent figures the bags or sacks, to be opened in the apparatus 410 are indicated by reference character S. The bags or sacks S
are shown in three positions during the handling process through the apparatus, these positions being indicated at Sl, S2 and S3, respectively.
Generally describing the bag opening procedure at position Sl the bas is positicned on a conveyor 415 for movement - into the apparatus 410. At position S2 the bag is inside the apparatus, having entered through an entrance opening 412a, in the totally enclosed and dustproof panelled enclosure (not sho~m), and is temporarily in a stationary position waiting to be opened and emptied, the conveyor 415 being stopped at the time. Further movement of the convevor deposits the bag at positioII S3 on a horizontal table 416 ready to be shaken or vibrated to settle its contents, during o~ after which it will be centered on the 30 table 416 and opened by cuttins along three of its underside corner edges to form a U-shaped flap by which it will be emptied.

lO~V~59 The bag is first cel-tered longitudincllly on the table 416 and cut transversely across its fo~ard and rean/ard ends, and is thereafter centered transversely and cut lonqitudinally alony one side, and perforated longitudinally to form a perforated hinge line alon~ its other side. Preferably, the shaking action Or the I vibrator table 416 continues during the centering and cutting steps~
after which the shaking action is terminated and the bag contents emptied as will be described. After emptying, the bag S will be automatically removed from its position at S3 and discharged from the apparatus 410 ~7hereupon the conveyor 415 is again actuated to deposit the next full bag at position S3 on the table 416.
Referring to Figures 4~ and 46, the apparatus 410 includes an overhead horizontal frame structure 411, four corner-located ~-vertical members 412, ~nd a lower horizontal frame structure 413, which are joined together to define an enclosure frame within which the various bag processing mechanisms of the apparatus will function.
This surrounding frame structure lends itself to dust-proof en-closure of the apparatus, as by attached panelling ~not shown), to isolate the mechanisms and the bag being opened from the en-20 vironment, thus providing an enclosed bag-opening system. This frame enclosure is supported by four corner-located supporting posts 414. Of course, the structural frame construction shown in Figure 45 i5 merely illustrative, and might be differently arranged to suit particular spacial or other requirements.
¦ ~?ith reference to Pigure 45 it will be understood that ~ the bags S enter the apparatlls from the left hand side on the - belt conveyor 415, only the discharge end of which is sho~. The conveyor 415 automatically and sequentially advances and stops, moving successive bags from position Sl to position S2, and thence 30 from position S2 to position S3 on the table 416. When a bag is in position S3, a plurality of vibrators 417, of a conventional 10~0~

type, vibrate th~ b~ cutting tabl~ 416 to causc th~ granular or powdery material ~ithin the ~ag S to settle into the lo~ler volume and recesses of the bag, thus assuring back up for the cutting action of the apparatus, as will be described.
Located at either end of the table 416 are respective and oppositely disposed air cylinders 418a and 418b 7hich are operated simultaneously to move their respective driven mem~ers or piston rods 419a and 419b forwardly at the same rate to center the bag beneath the gripping and clamping head 421 of the 10 apparatus. During this centering operation, the bag S is actually contacted and pushed into position by the respective heated cutter blades 420a and 420b mounted on the respective piston 419a, 419b.
As the centering of the bag at position S3 is being completed the gripping and clamping head 421, in its "clamping mode" by reason of its clamping plate 422 being in its extended or depending position relative to the stationary plate element 422a of the clamping head, is moved downwardly by the piston rod 424 of a vertical air cylinder 423 located thereabove. Upon contact by the clamping plate 422, the bag is clamped in its position S3 on to the table 416, thus holding the bag against buckling or arching as might occur as the heated cutter blades 420a and 420b continue to be forced against the bag to make respec$ive transverse cuts extending across the bag near its lower edge at each end.
The movement o~ the clamping and stationary plate elements 422, 422a of the gripping and clamping head 421 is guided by a pair of telescoping guides 425 which are respectively ¦ aligned with but spaced away in longitudinal direction from the ! air cylinder 423 at either side thereof as shown in Figure 45.
30 These tele~coping guides prevent the plate elements 422, 422a, and the piston rod 424 on which the stationary plate 422a is mounted, from pivoting with respect to the air cylinder 423, as might otherwise occur during operation.

- ~3-~Lo~ s~
t~hen cut~ing o~ th~ forward and rear~rard bag ~nds is complct~d, thc hcatcd cutter blad~s 420a, 420b are retracted b~
r~traction movement of the respective air cylinders 418a, 418b, and the clamping plate 422 is then lifted off the bag by retrac-tion movement of the vertical air cylinder 423. As the clampin~
and stationary plate elements ~22, 422a arrive at their retracted positions, the clamping plate 422 moves upwardly relative to the stationary plate 422a to expose the gripping spikes 426 below the clamping plate 422 as will be described, and to thus convert the 10 head 421 from its aforementioned "clamping mode" to its "gripping mode n, For this purpose, the clamping plate 422 is moved ver-tically relative to the stationary plate 422a by a pair of small air cylinders 428 mounted on the stationary plate 422a and whose respective movable piston rods 429 extend through appropriate apertures ~not numbered) in the plate 422a and are attached to the clamping plate 422. The clamping plate 422 is also appro-priately apertured to permit downward extension of each of the plurality of gripping spikes 426 therethrough, the length of the 20 spikes 426 being greater than the thickness of the clamping plate 422 so that they will pierce and extend about one inch or so into, and thus grip a bag positioned on the table 416 therebelow. The "gripping mode" of the gripping and clamping head 421 is illus-trated in Figure 49. Thus, when the air cylinders 428 are actuated to retract their respective piston rods 429, the spikes 426 are exposed below the gripping plate 422, and when the air cylinders 428 are actuated to extend t~eir pistons 42~ the clamping plate 422 is positioned and firmly held at an elevation below the pointed ends of the spi~es 426 so that it will function as a flat 30 surface gripping plate. It ~lill also be noted that the movement of the plate 422 from its retracted position to its extendçd position provides a "stripping" action by which a bag may be

- 4~ -10~

removed from the spi}~es 426.
Continuing with a description of the bag cutting and opening operation, ancl referrina to Figure 50, a longitudinal heated cutter blade 445, for forming a longitudinal cut extending between the previously described transverse cuts at the fortlard and rean~ard end edges of the bag S, is carried by the piston 442 of a transversely oriented air cylinder 441 ~rhich is mounted on a stationary angle-iron frame 416a. The frame 416a surrounds the vibrating table 416 as will be understood from a comparison of 10 .~igure 50 with Figure 48, and also mounts the longitudinally extending cylinders 418a, 418b..~ On the opposite side of the . vibrating table 416 atransversely extending air cylinder 443 is . - similarly mounted on the surrounding table frame 416a, its ex-tensible piston rod 44~ carrying a longitudinally extending per-forator bar 446. As illustrated in detail in Figure 58, the perforator bar 446 carries an aligned and spaced apart plurality of laterally projecting pointed spikes 447 which will perforate the bag S to form a perforated hinse line along the longitudinal edge of the bag which is opposite the aforementioned longitudinal 20 line of cut, thus to complete the forming of a U-shaped flap at the bottom of the bag during the cutting operation.
Referring again to Figure 50 ~,.hich shows the apparatus as it appears during the forming of the referred to longitu~inal.
.cut and oppositely disposed perforated hinge line, the air cy-. linders 441 and 443 are actuated simultaneously to extend their respective piston rods 442 and 4~'4 toward each other at the same rate so that the longitudinal cutter 445 and perforator bar 446 contact and first center the bag S in the transverse direction.
Promptly as the bag is centered, the gripping head 421, now in 30 its gripping r~oae, is lowered so that the gripping spikes 426perforate the upper wall of the bag as seen in Figure 50, and tne heated longitudinal cutter 445 and the unheated perforator bar 446 ~o~o~

continue their in~dr~ m~ ment to r~sp~ctively cut and perforate the opposite sides of the bag, thus to form the U-shaped flap at t~e underside of the bag. Contact of the clamping plate 422 against the upper wall of the bag prevents buckling or arching of the bag as the longitudinal cutting and hinge-forminy perforating operations are performed. ~lith the head 421 remaining in its downward position as shot~n in Figure 50, the longitudinal cutter 445 and perforator 426 are retracted by actuating the respective air cylinders 441 and 443, and the vibrator 417 is deactivated at 10 this time. The thus cut and opened bag S is now ready to be emptied.
Figure 47 diagramatically shows the underside of the bag S
after it has been cut as aforesaid in a U-shaped pattern of cut along cut lines 437, 438 and 438a, and having i~s fourth side per-~ forated, as at 440, to form a hinge line. The filled bag itself - has the general form of a paralelepiped of somewhat rounded con-tours with a generally rectangular lower face or wall 436.
Industrial and commercial bags of this type used for packaging bulk goods generally range in size from 3" x 14" x 20" to about 12" x 28" x 48" and the va~ious parts of the apparatus described 20 are suitable proportioned to accom~odate bags having this range of size although, of course, the apparatus could have greater or smaller dimensions for particular applications. The actual plane of the lines of cut 437, 438 and 438a and perforation 440 is about 1" to 1-1/2" above the planeof the bottom wall 436 so that there will be no "shelf" structure remaining on the main body of the bag as might otherwise be formed by inwardly turned edges at its underside and as would hold material to prevent its fall by gravity from the bag after the bottom wall 436 is cut. The cut bag is opened by dropping the flap 436 in the direction of the arrows to the dotted line position indicated at 43~ in Fig. 47.

- 4~ -.

The manner in which the thus cut and o~en~d bag S is emptied of its contents and therearter removed from the apparatus 10 will now be described with reference to Figures 51-54 and ~'igure 46.
¦ As seen in Figure 46 the gripping and clamping head 421 has an "A-frame" appearance formed by diagonal structural members ~30 at either end thereof ~hich are joined together to form an ¦ apex by which the head is pivotally mounted at its upper end.
j The pairs of diagonal members 430 are in spaced apart relation at ¦ 10 their lower ends. As seen in Pigure 45, the respective A-frames formed by members 430 lie within the same plane as the respective -telescoping guide rods 425.
As will be understood from Fig. 46, the gripping and clamping head 421 is mounted for pivotal movement on a longitu-dinally extending pivot rod 421a mounted on the upper frame 411.
The head 421 is maintained in its upright position as shown in full lines in E`igure 46 by the retracted lateral air cylinder 431 whose piston rod 432 is pivotably connected to a collar 432a on - -the vertical air cylinder 423, as shown. The opposite end of 20 the air cylinder 431 is pivotably connected to a fixed structural member 433 of the apparatus. ~hen the air cylinder 431 is actuated to extend its piston rod 432, it is seen from the dotted line showing in Figure 46 that the gripping and clamping head 421 will be pivoted in counterclockwise direction to bring its gripping and stationary plate elements 422, 422a to a position above a fixed, empty bag discharge chute 434. A flexible bafflie 435, mounted on the top of the Aischarge chute 434 as shown, guides each ~mpty bag on to the discharge chute as it is stripped ^ from the gripping head ~21 in manner to be described.

Figure 46 ~lso sho~Js the hinged mo~inting of the vibrator table 416, by which each opened bag is emptied of its contents. The vibrator table ur.it actually comprises the vibrator table 416, vibrators 417 and a hinged table element 416b, only the latter being hinged along the longitudinal hinge 448 to pivot from its horizontal posi.ion sho~,n in Figure 46 to the ver-tical, or bag-emptying position of the table as shown in Pigure 51. The movement is effected by an air cylinder 451 whose movable piston rod 450 is pivotably connected, as at 449, to the underside 10 of the hinged table element 416b. The opposite end of the air cylinder 451 is pivotably connected, as at 451_, to a fixed frame element 452 of the appara.us 410. In Figure 46 the piston rod 450 is shown in its extended position, by which the vibrating table 416 is retained in its horizontal position. Actuation of the air cylinder 451 to retract the rod 450 causes the table to drop to its vert~ cal position as shown in Figure 51.
Returning now to a description of the manner in which the open bag S is emptied and removed from the apparatus 410, reference is first made to Figure 51 which shows the longitudinal 20 cutter 445 and longitudinal perforator bar 446 in their retracte~
positions after the previously described longitudinal cutting and perforatins operations. The upper wall of the bag S is retained by the gripping spikes 426 against the gripping head 421, the pointed spikes 426 having roughened, knurled or threaded outer cylindrical surfaces to frictionally grip the jagged edges of the pierced bag walI at each spike. Of course, the transverse cutters 420~ 420b~ are also in their retracted positions.
;~ Air cylinder 451 (Figure 46) is actuated to retract its piston rod 450, thus dro~ping the vibrator table 416 to the 30 position shown in Figure 51, whereupon the bag contents (not -- ~8 --~v~is~

sho~n) drop by gravity into th~ product discharg~ chute 453 which is directly belo~ the table frame 416a. Simultaneously, the vertical air cylinder 423 is actuated to move the gripping head 421 further in the down~Jard direction until its gripping plate 422 lies essentially within, or slightly above, the plane formerly occupied by the top surface of the vibrating table 416 ~her; in its horizontal position as shown in Figure 46. Of course, as shown in Figure 51, as the contents of the bag S fall ~y gravity, the bag flap 436 formed by cutting as previously des-10 cribed, swings do-mwardly following the similar movement of the table 416, free movement of the rlap being facilitated by the perforated hing line 440 (Figure 47). Thus, the bag contents are emptied completely and rapidly into the product discharge chute 453. Discharge of the contents from the bag is also aided by compressed air which is momentarily supplied to selectively located hollow air spikes 427 (Fig. 51) which are also mounted on the stationary plate 422a and project through appropriate apertures in the clamping plate 422. Such air burst fills the void being created by the emptying of the contents of the bag ~hus 20 eliminating any forming of vacuum as might cause "hang up" of the discharging material. The air also removes wrinkles and purses the bag of its contents, and is discontinued as soon as emptying of the bag has been completed.
After emptying the bag S has been completed, the air cylinder 451 (Figure 46) is actuated to extend its piston rod 450, -i thereby causing the vibrator table 416 to swing upward to its horizontal position as seen in Figure 52. Such movement of the - table 416 carries with it the emptied bag flap 436 (Figure 51), and it will be noted that the flap 436 can be forced on to the 30 gripping spikes 426 of the rod 421 as the flap is sandwiched between the top surfàce of the table 416 and the bottom surface of the clamping plate ~-~2 ~hich has rem~ine~ in the pOSition shot~.~n in Figure 51. The table 416 is provided ~tith properly located comating holes or slots (Fig. 51) to clear the spikes 426 and compressed air nozzles ~27 during the referred to impaling of the bag flap 436 and the co~current bag-flattening action as seen in Figure 52.
Figure 53 shows that all of the empty bag S, including its underside flap 436, is impaled on the gripping spikes 426 after the gripping and clamping head 421 has been retracted from 10 its position as shown in Figure 51 to its start position as sho~n in Figure 53 by actuating the cylinder 423 to raise its piston rod-: 424. The flattened empty bag is now ready for discharge from the apparatus.
Figure 54 shows the gripping and clamping head 421 rotated approximately 65 in the counterclockwise direction, which is caused upon actuation of the air cylinder 431 to extend its piston rod 432, to which the head 421 is connected. As the head 421 carries the bag S to the position sho~m in Figure 54 it . deflects the flexible rubber or plastic baffle 435, which there-20 upon springs back into its vertical condition as shown. This action of the baffle 435 prevents the empty bag S from falling . . back into the region of the table 416, and also guides the flattened empty bag.S on to the discharge chute 434. The bag is stipped.from the gripping spikes 426 by movement of the clamping plate 422 away from the stationary plate 422a by actuation of cylinders 428 and the consequent extending movement of their piston rods 429 ~see Figures 45 and 48). The bag S discharges from the apparatus by gravity along the chute 434, and is there-upon collected with other empty bags for later compacting and disposal. The gripping and clamping head 421 is then pivoted from its position as shown in Figure 54 back to its upright positio~

, - 50 -10~

as sho~n in Fi~ 4~. h~ retraction movem~nt of air cylinder ~31.
It should be noted that the opening of a succeediny bag can b~
initiated as soon as the previous empty bag S has been fully raised by the head 421 from the table 416 to the position sho~n in Figure 53. This per~its o~erlapping of operating cycles, thus increasing the handling capacity of the apparatus 410.
Figure 55 illustrates in perspective the preferred con-struction of any of the heated cutter blades 420a, 420_ or 445.
The straight blade is formed by a plurality of blade segments 10 454, an electric heater cartridge 456 being passed through all of the laterally aligned blade segments as indicated. The blade segments 454 are respectively attached to a support bar 457 which, in turn, is mounted on the end of one of the air cylinder piston rods 419a, 419_ or 442.
Figure 56 shows a modified form of cutter blade in which the blade segments 455 have scalloped cutting edge configuration as shown, rather than straight configuration as are the blade -segments 454 shown in Figure 55. The use of such scalloped blade segments 455 are preferred w`nere unusually stiff or wrinkled 20 heavy walled bags require initial local penetration by the points : 461 of the scalloped blade edge to weaken the bag material for the subsequent cutting action of the middle length of the blade.
Figure 57 is an enlarged cross-sectional showing of the cutter blade shown in Pigure 55, and shows that the air cylinder piston rod 419a, 419 or 442 is conveniently attached to the cutter blade support bar 457 by a threaded connection 458 and a locking nut 458a. The individual cutter blade segments 454 (or 455) are each retained on the lower edge of the support bar 457 by a single shoulder screw 460, the mounting aperture 460a of 30 each blade segment being of larger diameter than the screw 460 to permit self-alignment of the blade segment as thermal expansion takes place when the blade is heated by the heater element 456.

.
.' ~' .

hcat resistant g~ et 462 of as~estos or like material insulates the support bar 457 from direct contact with the hot blade seg-ments 454 (or 455).
In Figure 59, a typical assembly of the perforator bar 446 o Figure 58 is sho-.n. Each perforator spi~e 447 is threadDdly attached as by threaded connection 447a to a support bar 446 ad-jacent to the lower edge thereof. The support bar 4~6 is threadedly attached, as at 458, to the piston rod 444, and a lock nut 459 secures the connection.

Of eourse, actuation of the infeed belt conveyor 415, and of each of the various air eylinders described is controlled by conventional mechanisms and air logic circuits as will be apparent to those skilled in the art and which therefore need not be described.
Although certain preferred embodiments of the bag opening method and apparatus OI the invention have been described in detail, i it is obvious that numerous adaptations, modifications, substitu-tions of parts and ~aterials will suggest themselves to those familiar with the art, and sueh variations are considered to ~e 20 within the spirit and scope of the invention.
WHAT IS CLAIMED IS:
.
.

Claims (45)

1. A method of opening and emptying a bag substantially filled with substantially non-combustible particulate material comprising momentarily contacting a wall of the bag at each of the elemental areas continu-ously along a proposed line of cut therethrough using a dull cutting edge heated to a temperature above the kindling or melting temperature of the material of which said bag wall is made, said cutting edge being pressed against said elemental areas of the bag wall using said particulate material therein as a backing and minimal relative horizontal motion between said cutting edge and each of said elemental areas during said momentary contact, thereby to form a cut through only said bag wall by a combination of heat and pressure, and emptying said cut open bag of said particulate material.

2. The method of claim 1 wherein relative movement of the cutting edge with respect to the bag provides momentary contact.

3. The method of claim 1 wherein said cutting edge is an edge of a freely rotatable wheel and wherein momentary contact is produced by rolling engagement of said wheel with said bag wall.

4. The method of claim 1 wherein said cutting edge contacts said bag wall for a period not exceeding about one second.

5. The method of claim 1 wherein said cutting edge is the edge of an elongated blade mounted for pivotal movement about an axis parallel to a surface of a bag to be cut and wherein momentary contact between said edge and said bag surface is produced by pivoting said blade into such contact.

6. The method of claim 1 wherein said bag wall is substantially rectangular having respectively opposite pairs of parallel side edges, and which further comprises producing a pair of generally parallel, spaced apart cuts through said bag wall each located substant-ially adjacent to the respective of one of said pairs of side edges by a combination of heat and pressure, and joining said parallel cuts by producing at least one additional cut through said bag wall by a combination of heat and pressure.

7. The method of claim 6 wherein said additional cut is produced substantially adjacent to one of said second pair of side edges, whereby a U-shaped flap is formed from said bag wall.

8. The method of claim 6 which further comprises joining said parallel cuts by forming a foldable hinge line in spaced apart relation to said additional cut and substantially adjacent to one of said second pair of side edges of the bag wall.

9. The method of claim 8 wherein said foldable hinge line is formed by a line of perforations through a wall of said bag.

10. The method of claim 6 wherein said bag has respectively opposite pairs of side walls and end walls conjoined with said bag wall respectively at said respective opposite pairs of said side edges, and said cuts are produced in said side and end walls.

11. The method of claim 6 wherein said parallel cuts and said additional cut produce an H-shaped pattern whereby two flaps are formed from said bag wall.

12. The method of claim 6 wherein said parallel cuts are produced by rolling contact of said heated cutting edge with said first pair of bag edges.

13. The method of claim 6 wherein said parallel cuts are produced by contacting each of said first pair of side edges with a cutting edge disposed parallel to said side edges and at an oblique angle with respect to the plane of said bag wall.

14. The method of claim 6 which further comprises substantially squaring said pairs of side and end walls with respect to said bag wall and settling said material within said bag prior to producing any of said cuts.

15. The method according to claim 14 wherein, after producing said cuts, said bag is supported from above while opening a space beneath said bag wall and allowing said material contents of the bag to drop from the bag.

16. The method of claim 15 wherein said bag is supported from above by piercing the upwardly facing wall of the bag using spikes to support said bag by mechanical engagement.

17. The method of claim 15 which further comprises forcing air under pressure into said bag wall supporting the bag and opening said space beneath said bag to enhance emptying of its said contents.

18. The method of claim 14 wherein said squaring and settling is produced by vibrating said bag while pressing flat members against opposite bag faces.

19. The method of claim 1 wherein said cutting edge is heated to a temperature between about 800°F and 1000°F.

20. A bag opening and emptying machine comprising table means for receiving a full bag to be opened and emptied, squaring means for rendering side and end walls of said bag sub-stantially perpendicular to a lower bag wall when on said table means, cutting means having means for heating the same for cut-ing a bag by a combination of heat and pressure, said cutting means being mounted adjacent to said table means, means pro-viding relative movement between said bag and said cutting means whereby at least one of said bag walls is contacted and pressed momentarily by said heated cutting means for producing a line of cut through the bag wall, and means for emptying said bag.

21. The machine of claim 20 wherein said cutting means includes a plurality of cutting means arranged with res-pect to each other to form a substantially U-shaped continuous line of cut having a pair of end termini providing a foldable flap of said bag when cut, and which further comprises hinge-forming means for producing a line of fold extending between said end termini of said lines of cut and along which said flap is foldable.

22. The machine of claim 21 wherein said hinge-forming means comprises a perforator bar having a plurality of spikes for piercing a wall of said bag, said perforator bar being mounted for movement whereby its said spikes will pierce said bag wall.

23. The machine of claim 20 wherein said squaring means comprises means for vibrating said table means.

24. The machine of claim 20 which further comprises bag holding means comprising a clamping and gripping head mounted for movement above said table means for engaging an upper wall of said bag on said table means, said clamping and gripping head carrying a plurality of downwardly facing spikes for piercing an upper bag wall to mechanically engage and hold said bag thereon.

25. The machine of claim 24 wherein some of said spikes are air nozzles, and which further comprises means for blowing air through said nozzles.

26. The machine of claim 20 which further comprises means for holding said bag, means for moving said table means away from said lower bag wall after said cutting and while said bag is held to permit gravity discharge of bag contents, said moving means comprising hinge means permitting pivotal movement of said table means, and means for holding said table means in a horizontal position and for pivoting said table means downwardly on said hinge means.

27. The machine of claim 20 wherein said squaring means comprises means for pressing against an upper wall and said side and end walls of a bag on said table means, and vibrating means for settling bag contents during squaring.

28. The machine of claim 20 wherein said cutting means comprises a pair of transversely spaced apart longitu-dinal cutters mounted substantially adjacent to a pair of oppo-site edges of said table means, and at least one transverse cutter for cutting across said lower bag wall between the lines of cut formed by said longitudinal cutters.

29. The machine of claim 28 wherein said pair of longitudinal cutters comprises a pair of heated cutting wheels, each of said wheels being rotatable about an axis arranged at an angle of about 45° with respect to the horizontal.

30. The machine of claim 29 which further includes means for pushing a bag in longitudinal direction between said wheels for rolling contact therewith.

31. The machine of claim 30 wherein said longitudinal cutter wheels are mounted on respective opposite side of said table means and adjacent one end thereof whereby said wheels contact said bag as it is being pushed onto said table means, and which further comprises pinch roll means mounted above said longitudinal cutter wheels for engaging and pressing said bag downwardly from above as it is being pushed between said longi-tudinal cutter wheels.

32. The machine of claim 30 wherein said transverse cutting means comprises an elongated cutter blade mounted for pivotal movement on said table means from an inoperative posi-tion therebelow to an operative, bag engaging position project-ing above said table means, means for pivoting said elongated blade between its said positions, and means for heating said elongated blade.

33. The machine of claim 28 which further comprises conveyor means for sequential feeding of full bags on to said table means and retractable stop gate means for stopping feed-ing movement of a bag when it is on said table means and for squaring a front end of a bag upon impact, said squaring means comprising vibrating means for settling bag contents while a bag is on said table means, means for retracting said stop gate means, second table means, means for advancing a bag from said first table means to said second table means upon retraction of said stop gate means, means for engaging at least one of the walls of a bag to hold the bag comprising a bag supporting head above said second table means, said pair of longitudinal cutters being disposed between said first and said second table means for producing longitudinal cuts in a bag while the bag is being advanced from said first table means to said second table means, and said transverse cutter being mounted adjacent to said second table means, said second table means comprising movable door means for allowing bag contents to empty under the force of gravity when said door means are opened and said bag supporting head is holding a bag, and means for removing an empty bag from said bag supporting head.

34. The machine of claim 33 wherein said bag support-ing head has a plurality of spikes for engaging a bag and means for stripping a bag off said spikes, and said means for remov-ing an empty bag comprises bag engaging roll means for pulling a bag away from said bag supporting head after the bag has been stripped off said spikes.

35. The machine of claim 34 wherein said bag engaging roll means includes a cushioned roller, and reaction plate means comprising a hingedly mounted plate and means for pivoting said plate towards and away from said cushioned roller to grip a bag.

36. The machine of claim 20 which further comprises sensing means including a movable bag stop member for indicating that a bag is centered upon said table means, means for engaging at least one of the walls of said bag to hold the bag from above when the bag is on said table means, means responsive to and coordinated with said sensing means for actuating said bag hold-ing means to grip and hold the bag, means responsive to and coordinated with said bag holding means for actuating said cut-ting means to make a cut extending substantially across said bag when the bag is in its centered position on said table means, and means for elevating said bag holding means to dispose of an empty bag after said discharge of bag contents.

37. The machine of claim 36, wherein said bag stop member abuts and senses the position of a front end of a bag, and said sensing means further includes a switch mounted to sense the position of the rear end of said bag.

38. The machine of claim 20 wherein said cutting means comprises an elongated blade formed of aligned blade seg-ments in spaced apart relation with each other sufficient to accommodate thermal expansion thereof.

39. The bag machine of claim 20 wherein said squaring means comprises vibrator means for vibrating said table means, and which further comprises means for engaging at least one of the walls of said bag to hold the bag when the bag is on said table means comprising a clamping and gripping head having a vertically movable element for engaging the upwardly facing wall of a bag, a pair of parallel and spaced apart elongated movable cutters mounted adjacent to respective opposite sides of said table means whereby a bag is received on said table means therebetween, and means for moving said parallel cutters laterally toward and away from each other for contacting and pressing respective substantially vertical walls on opposite sides of said bag for cutting each of the same.

40. The machine of claim 39 which further comprises a horizontally disposed elongated cutter extending transversely with respect to and within substantially the same plane as said pair of parallel elongated cutters and adjacent to a third side of said table means, the last said cutter being mounted for lateral movement toward and away from the center of said table means for contacting and pressing a substantially vertical wall of said bag for cutting the same to form a line of cut connect-ing said lines of cut formed by said pair of parallel cutters.

41. The machine of claim 40 which further comprises a horizontally disposed elongated perforator bar disposed transversely with respect to said parallel elongated cutters and movably mounted adjacent to the fourth side of said table means, said perforator bar being movable toward and away from said table means to perforate a substantially vertical wall of said bag and thereby form a hinge line extending between said lines of cut formed by said pair of parallel cutters.

42. The machine of claim 41 wherein said movable element of said clamping and gripping head mounts a horizontally stationary plate and a vertically movable horizontal clamping plate below said stationary plate, said stationary plate having a plurality of downwardly projecting spikes attached thereto and said movable clamping plate having means defining respective apertures thereof for passage of said spikes therethrough, the thickness of said clamping plate being less than the lengths of said spikes, and means for moving said clamping plate toward and away from said stationary plate between respective positions thereof respectively concealing and exposing said spikes there-through.

43. The machine according to claim 42 wherein said clamping and gripping head is further movable between a vertical position thereof wherein a bag on said table means will be con-tacted by said clamping plate thereof and a laterally oriented position thereof wherein said stationary and clamping plates face substantially towards a side of said machine.

44. The machine of claim 43 which further comprises an empty bag discharge chute mounted on said side of the machine, said stationary and clamping plates of said head being disposed substantially above said discharge chute when said head is in its said second position.

45. The machine of claim 20, wherein said cutting means has means for heating the same to a temperature between 800° F. and 1000° F.