US2403394A - Combined folding and stacking machine - Google Patents

Description

y 1946. J. E. PRESTON 2,403,394

COMBINED FOLDING AND STACKING MACHINE Original Filed March 27, '1942 6 Sheets-Sheet 1 3 N :2: o- 8 a C l a N 8 -W*"" a 2" I l l 52$ 0 52. 5; I [f 8 I L, I o I O 'Q/ 0 9 /a e T d C 5 v |l O L.

'8 N N a 3 INVENTOR h JoH/v E. PRES 7'0N o m 'BY N ATTORNEYS July 2, 1946. J. E. PRESTON 2,403,394

COMBINED FOLDING AND STACKING MACHINE Original Filed March 27, 1942 6 Sheets-Sheet 2 INVENTOR JZIHN E. P ii TON ATTORNEYS y 2, 1946- J. E. PRESTON 2,403,394

COMBINED FOLDING AND STACKING MACHINE Original Filed March 27, 1942 6 Sheets-Sheet 3 INVENTOR J'amv f. Pea" 701V BY ga 4% ATTORNEY y 1946. J. E. PRESTON 2,403,394

COMBINED FOLDING AND STACKING MACHINE Original Filed March 27, 1942 6 Sheets-Sheet 4 FIG-9 INVENTOR JBH/v :7 P/iE'S TO/V ATTORNEY- y 1946. J. E. PRESTON 2,403,394

COMBINED FOLDING AND STACKING MACHINE Original Filed March 27, 1942 6 Sheets-Sheet 5 o o no /A on NB '2 J 70 D FIG-ll r 5 I06 5 l 5%; --I n I I III n2 INVENTOR J'a/IW 5. Pass ro/v ATTORNEYS July 2, 1946. J. E. PRESTON 2,403,394

COMBINED FOLDING AND STACKING MACHINE Original Filed March 27, 1942 6 Sheets-Sheet 6 FIG-I4 INVENTOR JOHN 5. Pass TON BY ad'wljtf ATTORNEYS Patented July 2, 1946 7 COMBINED FOLDING AND STACKING MACHINE John E. Preston, Northport, N. Y., assignor to The American Laundry Machinery Company, Cincinnati, Ohio, a corporation of Ohio Original application March 27, 1942, Serial No. 436,466. Divided and this application December a, 1943, Serial No. 513,332.

This invention relates to combined foldingand stacking machines and to the control apparatus or devices therefor. It has more particular, relation to machines for folding and stacking small flat articles made of any material, such as paper sheets, or more or less limp articles made of textile fabrics, for example, sheets, towels, pillow slips or the like.

In folding and stacking flat articles it has been customary to operate the combined machine in cycles, one cycle beginning with the folding operation or operations and terminating with the completion of the stacking operation upon the same article, whereuponthe cycle was repeated upon the next succeeding article, and so on. In such machines, especially when adapted for folding and stacking articles of various lengths, it has frequently happened that the length of the article taken with the established time delay in stacking, or other causes, has prevented the article from fully entering the stacking position before operation of the stacker, with the result of an improper or faulty stacking operation or the jamming of the stacking mechanism.

One object of the present invention is to overcome this objection to prior machines for the purpose, and to insure proper stacking and prevent jamming at all times.

Another object is to provide an improved combined folding and stacking machine in which the folding and stacking operations are initiated and 3 Claims. (Cl. 27082) omitted to expose interior operating mechanism; Fig. 2 is a plan view of the machineshown in Fig. 1; Fig. 3 is an end elevation, illustrating the upper longitudinal folding mechanism shown in Fig. 1; Fig. 4 is a detail longitudinal section on the line 4-4, Fig. 3; Fig. 5 is a sectional elevation on the line 5-5, Fig. 2; Fig. 6 is a cross section on the line 68, Fig. 2; Fig. '7 is an enlarged longitudinal sectional elevation, on the line 1-1, Fig. 2; Fig. 8is a detail sectional elevation of the cross folding blade mechanism, on the line 88, Fig. 7; Fig. 9 is a sectional elevation on the line 99, Fig, 1; Fig. 10 is an enlarged detail fragmental view of the stacker counting mechanism, looking in the direction of the arrows lll-l0, Fig. 9; Fig. 11 is an enlarged side elevation, corresponding to Fig. 1, of the clutch mechanism: Fig. 12 is a detail section on the line 12-42, Fig. 11; Fig. 13 is a detail section on ,the line l3-I3, Fig. 12; Fig. 14 is a diagram, illustrating the circuits for the timing and measuring control devices; and Fig. 15 is a detail diagrammatic view of certain switch mechanism.

In some respects, the folding machine of the present invention is capable of wide use and for a variety of purposes. Generally speaking, it embodies means for performing an operation with go on simultaneously, but upon different articles 1 in the line.

Still another object is toprovide improved that they operate simultaneously and not in sequence, thus insuring full delivery of the work to the stacker before it begins to operate.

A further object is to provide improved combined folding and stacking mechanism of the character described, in which the stacking machine may be manually operated at any time, such as to clear the machine of the last article at the end of a series.

Further objects of the invention in part are obvious and in part will appear more in detail hereinafter.

This application is a division of my prior application for Folding machine and control therefor, filed March 27, 1942, Serial No. 436,466.

In the drawings, Fig. 1 is a side elevation of one form of folding machine embodying the invention, certain of the panels and guards being respect to each of a series of articles differing in length, means for producing relative movement between such performing means and the article, and time delay means operating over a period of time while such relative motion is going on for delaying and determining the time and place of performance of such operation with respect to the articles. I

My copending application for Sequence timer and measuring control, Serial No. 436,465, filed March 27, 1942, illustrates, describes and claims various embodiments of such a machine. Ac-

cording to that disclosure, each of a series of articles may be measured and after a preselected time delay period its length may be indicated or recorded. 01', each of a series of articles varyingin length may be out or punched or indented at one or more points in proportion according to its total length, such as at its middle point, or at a point one-third from its end, orat several points. Or, sheets of paper of varying length may be imprinted, or some other operation may be performed upon them, at one or more points proportioned according to their length.

For convenience, and in no sense of limitation, I have here illustrated as one suitable embodiment, a machine for folding relatively small more or less limp fabric articles, such as pillow slips,

' ribbons Ii.

derstood not to be so limited but to include all mechanism within the scope of the claims appended hereto. The machine illustrated first will be described in detail, following which its various attributes will be set forth in amplified form as the description proceeds.

The machine shown in the drawings is designed to accomplish two kinds of fold in the article, i

to-wit, a longitudinal'fold or folds, and a, transverse fold or folds. Thus the machine includes in order elements which may be generally referred to as follows:

Afeeding device E upon which the articles are delivered or laid out and which accomplishes their introduction to the conveying and longitudinal folding mechanism;

- Longitudinal folding mechanism F which produces one or more folds extending longitudinally of the articles;

One or more transverse folding devices G which produce cross folds in the article; and

A collecting or stacking device H where .the product of the machine is collected in orderly piles ready to be removed.

All of the foregoing instrumentalities are more or less automatically controlled in manner and by means tobe described.

The machine shown embodies a frame it, at

' one end of which (the left hand end in Fig. l) is supported the feeding device E, and which also supports the longitudinal folding apparatus F, the cross folding mechanism G, and the stacking mechanism H.

The feeding device The feeding device E includes gonveying ribbons Ii traveling over front and rear rolls l2, l3, Figs. 1 and 7, with the top run moving toward the rear end of the machine or away from the operator. These ribbons are driven by a sprocket ll on the shaft II of one of the rolls connected by a chain I. with a sprocket on a shaft i1 provided with a pulley i3 connected by belt i3 to a pulley on the shaft of a suitable driving motor 20.

Roll shaft 2| has fixed thereto a-pair of smaller rolls 22 which drive a set of ribbons 23 running over another roll 23 supported in suitable bearing brackets at the feeding end of the machine, and roll 24 drives another pair of ribbons 25 running over an idle roller 23. The idlers 21 and 23, suitably mounted, provide belt tightening means. On account of thelarger size of rolls I2 with respect to the rolls 22, the ribbons 33, 23 travel at a slower speed than the ribbons H, thereby producing spaces or gaps between successive articles when the feeding device formed by the belts 23, 25 delivers the articles successively to the conveying articles to and through the longitudinal folding mechanism, and'thence to the cross folder, as will later appear.

. Longitudinal folding mechanism The longitudinal folding mechanism F includes two side wings 33, 3!. Figs. 3 and 5 illustrate how these wings consist of metal sheets rolled or bent upwardly and inwardly progressively, as illustrated at 33a and 31a. As the article advances with the conveying ribbons ii the outer edge portion of itsright hand part (looking forward) is rolled over by the right wing 3ia to lie upon the middle part of the article and later its left part is rolled over by the left wing 33a to be superposed upon the already folded right part. To hold These conveying ribbons carry the it is held down by a riding plate 32, which rides upon the moving article and upon the upper surface of which the right edge of the article is folded. This plate, in the present machine, is made thin and it is also yieldable so as to offer light downward pressure and yet enable the plate to rise slightly and accommodate itself to any multiple or extra thickness of the article, as at hems. It also is electrically conductive, forming part of the circuits, as will later appear. For this purpose the riding plate 32 is carried by a support consisting of a thin flexible metal plate 32a mounted on support brackets 33 but insulated from other parts by washers 32b (Figs. 3 and 4). The folding line for the right hand part of the article is determined by the right hand edge of the riding plate 32. The outer edge portion of the left hand part is rolled over by the wing 30 upon a second riding plate 34, the forward edge of which is supported by the upper face of the folding wing 3|. The folding line for the left part of the article is determined by the left band edge of the plate 32 and as the folding operation proceeds the respective right and left folded parts are separated from'each other and from the middle part of the article by the riding plates 32, 34. 1

The earlier portions 30b, 3"), of the folding wings, where they are first engaged by the article, are progressively more and more inclined to the horizontal plane, as shown in Fig. 3. This simrple elevation of these folding plates, out of the horizontal to an inclined position, accomplishes the two folds with more certainty. The inclination is in favor of the turning over or rolling movement produced by the folding wings along the outer edge portions of the right and left parts of the article and materially assists their operation.

Usually a portion of the folding plates is enclosed by a cover plate 35 hinged at 33 to enable it to be readily lifted up when desired.

shaft 43 is one end of a 'coil spring 53, the oppo-' site end of which engages with bracket 33. Thus the disks are biased downwardly in a clockwisedirection, Fig. 4, to cause them to press the work into engagement with V-grooved lower rolls 4i, Figs. 1 and 6, lying beneath the work. The rollers ll are supported on a shaft 42 carried by the frame, said shaft also being provided with suitable driving means, such as a sprocket 43 connected by chain 44 to a sprocket 45 or roll shaft l2.

With the foregoing arrangement, the grooved rollers are driven along with the receiving belts 23, 25 and the conveyer belts ii, and intimed relation with the travelling work. The disks lie close to and in line with the edges of the riding plate 32 and with it determine the fold lines. Their purpose is to pre-crease each article, along the proper fold lines, just as it reaches the riding plate and begins to be turned up by the inclined ortions 30b, Nb of the folding wings. The

rollers also assist, of course, in causing feeding advance of the article.

First cross folding mechanism Each article, when it leaves the longitudinal folding mechanism, is subjected to one or more cross folding operations. The flrstcross fold is produced'by cross folding mechanism shown in detail in Figs. 7 and 8. It includes a folding blade I 51, lying in a vertical plane above the work andarranged to engage each article at a preselected point along the length thereof and move it downwardly and tuck it into engagement in the bite between a pair of pinch rolls, one of which, I3, supports the feeding belts II, and the other of which, 56, is supported in floating bearings 56,

Fig. 1, one at each end. Springs 60 bias roll 50 .a suitable frame 6|. Springs 62 bias it upwardly,

and it is moved downwardly by the armature 63 of a solenoid 61, said armature being connected by links 65 to levers 60 pivoted at 64a to the frame and connected respectively to opposite portions of the folding blade by links 66, 10. Downward motion of the folding blade is limited by engagement of a shoulder 63a on'the solenoid armature with the solenoid housing, and a housing 1| is provided to enclose the mechanism.

When but a single cross fold in the article is desired, the article, when it leaves the folding rollers I3, 58, drops down to a curved conveying port pivotally, at 65, left and right stack supporting plates 06, 01 provided with inwardly extending fingers 66a, 01a, which extend into notches in the side edges of the lifting plate 02, as shown in Fig. 2. 7

Side brackets 64 also support shafts 00, 00, Fig. 7, carrying pulleys' I60, III over which travel round belts I02, the upper run of each of which extends slightly above the upper surface of the lifting plate 03, when the latter is in its lower p sition, said lifting plate being slotted for the purpose, as shown at I02, Fig. 2. I

Any article delivered by the belts 12 to the.

: stacking device moves forward -on top of the plate 12 along which it slides to ribbons 13 which toward theend of the curved plate extend above it and beyond its end and which deliver the article to the belts of the stacking mechanism H, as will later appear.

Second cross folding mechanism While in some cases the articles may be sufficiently finished if cross folded but once, nevertheless the present machine is-arranged to provide a second cross fold when such is desired.

The mechanism for this purpose includes a second folding blade 15 mounted on one arm 16 of a lever pivoted at 11, the other arm 18 of which is provided with a head 19 actuated by the armature 80 of a solenoid BI. Sail folding blade is normally biased to retire by a spring 82. At the appropriate preselected time, said folding blade 15 moves forward, engages the article depending beneath the rolls I3, 58 and held 'in the bite thereof, and advances the article into the bite between the roll 58 and another roll 83 supported in the frame and lying beneath it. The floating bearings 59, as shown in Fig. l, are angularly disposed, so that the bias of spring 60 upon roll 58 provides yielding pressure of said roll-against both of the rolls I3, 83. As shown in Fig. 1, the shaft of roll 63 is provided at one end with a sprocket 04, enabling it to be driven by the same belt I6 which drives roll I3. Articles subjected to a second cross folding operation between rolls 58, 63 are delivered to a curved plate 85 along which they slide to the same belt 13 before referred to, which carry them into the stacking mechanism now to be described.

Stacking mechanism stacking plate 96, in its lowermost'poeition, and into contact with the belts I02 which advance the article into the stacking device with it leading edge engages a movable stop device I00, Figs. 7 and 10. The stack of finished articles is built up by additions to one of its ends, here to its bottom, and the rising pile is guided and supported by upstanding posts I05.

Suitable intermittently operating mechanism is provided for operating the stacking mechanism, preferably in timed or synchronized relation with the cross foldingdevices before described. As illustrated, the operating mechanism includes a shaft I06 provided with a" two-lobed cam I01 adapted to actuate one arm I100 of a lever pivoted at I09, the other arm IIO of which lies beneath the lower endof, and elevates, the post 92 and the pusher plate 63 carried thereby.

On shaft I06 are mounted, for rotation together or as a unit, a ratchet wheel III and a sprocket II2, the latter connected by a driving chain Hi to a small sprocket II4 on the main driving shaft I1, so that the unit I I I, II2 rotates continuously. On the same shaft I06, and pinned thereto, is an operating member II5 having two arms diametrically opposed, one of which carries a T- shaped latch lever H6, while the other carries an L-shaped lever II1, arms of the two levers .being cross connected by a link H0, and the link and lever system being biased by a tension spring II9 to engage a tooth I20 of lever II6 with the teeth of ratchet III, such operation normally being prevented by an abutment I2I on a lever I22 pivoted at one end at I23, and at its opposite end connected to the armature I24 of an electromagnet I25. One end of a latch lever I26 normally lies behind a pin I21 on the arm II5, holding it in position with the upper The stacking mechanism is illustrated more or arm of lever II6 against'the abutment lug I2I, as shown in Fig. 11. Latch lever I26 is biased by a spring I20, which holds'it against a stop I29. When the arm II5 rotates (turning clockwise in Fig. 11) the pin I21 rides beneath the lower edge of lever I26, lifts its right hand end and passes beyond it, the lever dropping into place into the position shown, ready for another operation.

The stacking mechanism operates as follows:

In the normal position of rest of the parts, shown in full lines Fig. 7, in Fig. 9 and in Fig. 11, the tack of previously folded articles rests upon the left and right fingers 96a, 91a and the lifting plate 93 is at a lower level with the belts I02 extending slightly above it. A previously folded article may be lying upon plate 62 if the machine has been in continuous operation. The parts are so timed, as will later appear, that when the folding blade .51 is again depressed to fold the next article, by energizing solenoid 61, solenoid I25 is also momentarily energized, thus raising lever 922 and releasing the lever!" to the effect of its biasing spring II3. Dog I20 thereupon enters a recess of the ratchet wheel III, coupling the member H to rotate with the ratchet wheel and thus turn shaft I06 and the two-lobed cam I31. Immediately upon release of lever Ili solenoid I23 is deenergired, lever I22 drops and the lug I2I assumes it original position, ready to engage a trip arm of either trip IIS or III, when it next comes around, thus disengaging the dog I23 from the ratchet wheel and terminating the operation of the half revolution mechanism. During the one-half revolution of shaft I06, one of its cam lobesswings lever I08, III! and elevates post 32 and the lifting plate 33. Plate 33 carries up with it any article previously deposited upon it, adding it to the pile, and lifting the pile so that the lowermost fresh article reaches a position above the lifting fingers. The lifting plate then moves down again to its original position, and immediately receives the next article, which by the simultaneous energization of solenoid 61 has just been folded by blade 51 and has then been delivered to the stacker by one of the chutes I2 or 35. Pivotal mounting of members 36, 91 permits free upward movement of the articles, as will be readily understood. When the two solenoids 31, I25 are again energized simultaneously the same folding and stacking operations are repeated. Thus, operation of both the stacker and the folding mechanism is initiated and goes on Counting mechanism While not essential, the stacking mechanism may be provided with counting mechanism constructed and arranged to operate as follows:

The counting mechanism is best illustrated in Figs. 9 and 10. It includes an arm I33 mounted to rotate freely on a stub shaft I3I. This arm carries a pawl I32 yieldingly held in engagement with the teeth of a ratchet I33. An auxiliary finger I34 is pivotally mounted on the pivot shaft 33 on which the right-hand stack supporting plate member 31 is pivoted. This finger has connected thereto a depending rod I35 sliding in a guide I36 and biased to the position shown in Fig. by a compression spring I31. The lower end of rod I35 lies Just above an end of the arm I33. Auxiliary finger I34 extends into the path of vertical article movement in the same manner as fingers 31a. Therefore, when the newly arrived article and plate 33 move upwardly and turn plates 33, 31 about their pivots, auxiliary finger I34 is also tilted, causing rod I35 to move downwardly and actuate arm I33, turning ratchet I33 and shaft I3I the distance of one tooth, to a new position, where it is held against return by a detent pawl I33.

Ratchet wheel I33 has aiiixed thereto a bar member I43, opposite ends of which extend slightly beyond the wheel periphery. During each half revolution of the wheel one end of this bar engages one arm I of a latch member pivoted on the shaft I42, rotating it counterclockwise in Fig. 10, and causing the upper end of its other arm I43 to move away from its position beneath 9. lug I44 on the back of the stop plate I44. Then the leading edge of the next towel or other article fed into the stacking mechanism moves beyond the lowered stop plate I04 until it engages a fixed stop plate III4a. Therefore, one towel in each group of articles, corresponding to the number of ratchet teeth in one-half the circumference of ratchet I33, extends beyond the face of the stack. If the ratchet wheel has fifty teeth, for example, a short piece of every twenty-fifth towel projects beyond the face of the stack, so that the towels readily may be taken off in multiples of twentyflve. The next time the stacking mechanism operates, an extension I43 on the lever arm Ill engages the lower end of stop I34, restoring it to its original position with its lug I44 bove the lever arm I43.

Of course, this arrangement always leaves the last towel, folded, in the stacking device below the stack supporting plates, when the machine is stopped. Accordingly I provide the mechanism with a rod I46, Fig. 1, connected at one end to lever I22 and the other end extending to a convenient upper position. By pulling up on this rod the trip 'lever H6 or I" may be released and the stacking mechanism caused to operate once to clear it of the last folded article.

Usually the mechanism is also provided with a totalizing counter. In the arrangement shown I provide such a counter of conventional form, indicated at I", Fig. 10, the operating arm I43 thereof being connected by a link I43 to a lug on the auxiliary finger I34, so that this totalizing counter will be actuated once for each actuation of the stacking device and indicate and record the number of towels folded, to check production of the mechanism.

General operation Summarizing the operation of the mechanism as a whole, described thus far, articles to be folded are delivered in succession to the feeding belts 23, 25', either manually by an operator, or they may be discharged upon the feeding belts from a previous mechanism, such as the delivery belts of a flatwork ironer. ries each article forward and delivers it to the traveling belts II of the longitudinal folding mechanism, the side wings of which fold the side edges inwardly around the riding plates as the article moves alon with the belts. When the article reaches the cross folding mechanism, including folding blades 51 and 15, it is engaged by oneof said blades, if one cross fold is desired, or in turn by both of said blades, when two cross folds are desired, and is thus introduced to and passes through the folding rollers, which deliver it to one or the other of the plates I2, 33 along which it slides to the belts 13 which deliver it into the stacking mechanism. There it is added to the bottom of the pile being formed, is counted with others, and the record of the count is in-' dicated and recorded in the totalizer.

Control mechanism 3 Since, in the specific machine illustrated in the drawings, the folding blades are actuated by electromagnets or solenoids and the operation of the stacking mechanism is controlled by another electromagnet, the control system obviously is of electric form. The circuits therefor are illustrated in Fig. 14. together with conventional illus- The feeding device cartrations of the machine par This n l SY tem is arranged and operates as follows:

The control system shown permits several distinct folding operations, which may be individually selectively chosen by operation of the ganged switch 200 shown in Fig. 15. The said switch 200 in the wiring diagram of Fig. 14 for convenience has been shown with its several elements 20 I, 202 and 203 distributed in their proper places in the various circuits but it should be understood that in actual construction and operation all three of said elements "I, 202 and 203 are most conveniently arranged for operation from a single knob or control member.

The various folding operations which may be performed with this control system are as follows, it being understood that in all cases the article may vary in length between a preselected maximum and a preselected minimum:

1. A single transverse fold may be made at the mid-point of the length of the article.

2. A' single transverse fold may be made at any other point spaced from' the mid-point of the article, the one-third point being hereinafter selected for illustration and description.

3. The article may be folded first at its midpoint, and then again at the mid-point of the new half length, thus accomplishing what we will term the half and quarter type of multiple fold.

4. The article may be folded first on a line spaced one-third of its length from the trailing edge, and finally on a line spaced one-third of its length from the original leading edge, thus accomplishing what we will term the one-third-twothird type of transverse fold.

The general type of electronic control here illustrated, in its essential features, is similar to that illustrated and described in my said copending application, Serial No. 436,465, hereinbefore referred to,.to which reference may be had if desirable or necessary. Its essential features will be here described only to an extent necessary for an understanding of the operation of the apparatus here shown.

Of the three elements of switch 200, each has three positions, left, middle and right, designated in the diagram by the reference letters L. M. and R. In element 202 the L and M contacts are connected by a bridge 202a.

The parts of the folding machine, including the operating solenoids, shown in Fig. 14. require no special description, because they correspond to or'are the same parts illustrated in Fig. 1, although it should be noted that the two views are reversed, with the work moving from left to right in Fig. l and from right to left in Fig. 14. In Fig. 14 the work travelling with the conveyor belts II engages in succession two trip fingers, marked I, 2, and while in contact therewith interrupts a circuit from thetrip finger to an insulated conducting riding plate 32 to be referred to.

As in my copending application, the electric control system includes four electronic discharge valves marked respectively A, B, C, D. These valves are used as control devices by variation of the potential in the grid circuit to adjust it to or beyond the critical control value, thereby making the plate circuit conductive or nonconductive, as the case may be, and thus producing a delayed controlling effect in or by the plate circuit. v

Electronic tubes or valves A and B are respectively in operative conjunction with the trip flngers l and 2. Each constitutes a sensitive electric relay responsive to passage of an article past said contacts. As to these tubes, when their plate circuits become conductive, tube A energizes a relay 20!, moving its armatures 205, 206 to their a positions, and tube B energizes a relay 201, moving its armatures 208, 208, 2I0 to their a positions. The effect of such movements and their corelation with the entire control operation will soon appear.

As in my copending application referred to, control of the operating solenoids 81 for the folding blade 51, and 8| for the folding blade I5, is dependent upon the total time for discharge of one or more of capacitances 2II, 2I2, associated with time delay relay valve C, and M3, associated with time delay relay valve D.

Current for charging the capacitances and operating the electronic tubes and associated relays is supplied from the secondaries 2H, 2I5, 2I6 of a transformer generally designated 2II, which derives its power from a conventional voltage control transformer 2I8. Secondary 2 is provided with a conventional voltage divider 2I9, secondary 2I5 with a conventional voltage divider 220 and secondary 2I6 energizes the heater filaments of all four electronic tubes, intermediate portions of the heating circuits being omitted for simplicity.

Time delay relay C, when its plate circuit is conductive, energizes a relay 2III, moving its armature 220 to position a, while time delay relay valve D, when its plate circuit becomes conductive, energizes a relay 2', moving its armature 222 to its a position.

In the arrangement shown in said copending application referred to, when it is desired to produce a single cross fold in an article at any point located upon it proportionately to its length, a charged capacitance, such as the capacitance 2 in the cathode-grid circuit of discharge valve C, is permitted to discharge at one rate when the leading edge of the article engages trip 2 and until its trailing edge engages trip I whereupon its discharge is continued, but at an increased rate, until the discharge is complete, whereupon the operating solenoid 61 is energized and the cross fold is produced. In such case tube D, controlling the production of a second fold, is made inoperative or ineffective by opening a manually operated normally closed switch 8Ia. The present control system is arranged to perform a one fold operation here precisely in the same manner as in said copending application. Again, in said copending application, the one-half-one-quarter type fold is produced by the use of time, delay relays C, D and associated capacitances, such as 2| I, 2I3, with the rates of discharge of the capacitances 2| I, 2I3 varied during the time delay period in such maner that tube 0 energizes solenoid 61 to produce a fold at the mid-point and tube D energizes the solenoid 8| to produce a fold at the quarter point. The completely folded article, as it is delivered to the curved 'plate lies upon it with the leading and trailing edges of the article superposed upon each other and lying above the cross fold at the mid-point. Again, the present control system performs that operation in exactly the same manner and by the same means as in said copending application.

As to the production of two cross folds at the one-third and two-thirds points, however, the present control system is arranged to operate differently from that of the said copending application, in that the time delay which deter! mines the location of the second fold, controlled by the discharge of capacitance 2I2, is completed at a single unvarying rate and is not variable by increments during different portions of the discharge, and therefore depends entirely upon the total initial charge given to capacitance H3 instead of the manner in which that charge is dissipated at two different rates.

One-third-twO-thirds multiple fold For convenience the operation will first be described with' reference to the production in an article already folded longitudinally in the longitudinal folding device F of two cross folds, the first produced by blade 51 at a point located onethird of the total length of the article from its trailing edge and the second, produced by blade 15 at a point located one-third of the length of.

the article from its leading edge or two-thirds of its length from its trailing edge.

To that end switch 200 is turned to its R position and manual switch Ila is closed, as illustrated in Fig. 14.

It is assumed that lead wires L1, L: are connected to a source of current and that the circuits are all energized.

The plate circuit of valve A is nonconductive; relay 2 is deenergiz e and its armatures 205, 206 are in their b positions, because the grid circuit of said valve is subjected to overbia and the grid potential is above the critical control value. The biasing circuit is as follows: from the grid of valve A, through resistance 31, conductor 302, trip finger Linsulated conducting riding plate 32, conductor 303, resistance "4 at the voltage divider 220, conductor "6 and through the cathode back to the grid of valve A.

Likewise, the plate circuit of valve B is nonconductive; relay 2'" is deenergized and its armatures 208, 209, 2III are in their b positions, because the grid circuit of this tube is overbiased and its potential is above the critical control value. The circuit is as follows: from the grid of valve B by way of resistance 201, conductor 398, trip finger 2, insulated conducting riding plate 32, and by way of conductors 203, resistance 3M, conductor 305 and conductor 30! and through the cathode back to the grid of valve B.

At valve C the switch element 203 is in its R position and the two capacitances 2II, 2I2 are included in the circuits in parallel, so that they act as one. These capacitances have been selected or chosen of such size that the total charge they will accept, when dissipated in the manner to be described, will produce such time delay as will cause the first folding blade 51 to be operated when a point located on the article one-third of its total length from its trailing edge registers with the folding blade, regardless of the actual length of the article, within reasonable limits, as will appear.

These two condensers are charged by a circuit as follows: from the lower plates of said condensers by way of conductor 3", armature 2.8 in its b position, conductor 3| I, voltage divider 220, secondary 2I5 to the point 2I2, conductor 305, conductor 3I2, and by way of the cathode and grid circuit of valve C and conductor 321 to the upper plates of the condensers. As the result of the inclusion ,of said capacitances in the cathode-grid circuit the grid potential of this valve also is above the critical control value, its plate circuit is nonconductive; relay 2|! is de- 12 energized; its armature 220 is in its b position and the circuit by way of conductors 3, 2|! to and through the operating solenoid 61, I2! is open.

At valve D, the capacitance 213 alone is in circult, but it is not charged, and its chargin circult is open, to be closed later, as will appear. Its plate circuit is conductive, relay MI is energiled and armature 222 is in its a position, so that the circuit to operating solenoid 8| by way of conductors 3I6. 3I5 is closed and the folding blade I! is in its advanced position. But this is immaterial, as will also later appear.

Let us assume, now, that an article to be carried by the belt conveyor II, advances in the machine until its leading edge engages trip finger I. This opens the biasing circuit before described for valve A, its relay 204 is deenergized, and armatures 205, 208 move to their b position. Nothing else happens.

The leading edge of the article next engages trip finger 2, and because in this apparatus the two tripflngers I, 2 are space apart the length of the minimum length article to be folded in the machine, both trip fingers will be engaged by the article simultaneously. When the trip finger 2 is engaged, the overbiasing circuit for the grid of valve B, before described, is also opened, its plate circuit becomes conductive, relay 201 is energized, and its armatures 208, 209, 2! move to their a positions. Two effects are produced, as follows:

A charging circuit is established for the capacitance 2I3 of valve D, as follows: from the lower plate of said capacitance by way of conductor III, the arm of switch 2M in its R position, conductor SIB, armature 2I0 in its a position,

conductor IIO, voltage divider 2| 9 to the point 2I2, conductor 305, conductor 320, and by way of the cathode-grid circuit of valve D back to the upper plate of capacitance 2I3. Said capa itance charges instantaneously and imposes overbias on the grid circuit, raising its potential above the critical control value. Consequently, the plate circuit of valve D becomes nonconductive, relay 22I is deenergized, armature 222 moves to its b position, and the circuit to the operating solenoid ll opens and folding blade 15 retires ready for operating advance.

Also, a discharging circuit is completed for the capacitances 2 I I, 2I2 of valve C, as follows: from the lowerplates of capacitance 2I2 by way of the arm of switch 202, and from the lower plates of capacitance 2 by way of conductors 32I to thepoint I22, thence by way of conductor III), armature 208 in its a position, conductor I23, resistance 324, resistance 325, resistance 226, armature 205 in its a position, and conductor 321 to the upper plates of said capacitances. Discharge of said capacitances continues at a rate dependent upon the total value of resistances 224, I2! and 12!, all of which arein circuit with the capacitances. The rateof discharge is consequently low. As discharge continues the potential of the grid circuit of valve C approaches the critical control value. This effect continues until the trailing edge of the article passes trip finger I, a period of time obviously dependent upon the total length of the article (whatever that may be between the preselected minimum and maximum) reduced by the constant distance separating the trip fingers I and 2. When the trailing edge of the article passes trip finger I, the latter again engages the conducting riding plate 32, reestablishing the overbiasing circuit for valve A.

13 whose plate circuit again becomes nonconduc; tive, deenergizing relay 2, so that armatures 2.3, 203 move to their b positions. The movementv of armature 205 shorts out the two resistances 323, 326 by way of conductor 328 and the arm of switch 202 in its R position. As the result, discharge of the capacitances 2! I, 2l2 proceeds, but at a higher rate, the value of resistances 324, 323, 326 being so selected that when the capacitances 2, 2|: have been completely discharged by increments, first at a low rate and second at a higher rate, the appropriate point on the article, one-third of its length from the trailing edge, registers with folding blade 51. At this instant the potential of the grid circuit of valve C reaches the critical control value, its plate circuit becomes conductive, relay 2 l 9 is energized, armature 220 moved to its a position and the circuit through wires 3, 3|! to operating solenoid I1 is closed, producing advance of the folding blade 31 to tuck the article between the first folding rolls I3, 53, for the production of the first cross fold.

The trailing one-third of the length of the article never moves horizontally beyond the first folding blade 31, but follows a path horizontally to the left in Fig. 14 to the folding blade and thence down through the bite between the folding rolls i3, 53. Consequently, no matter what is the actual length of the article (variable as it is between the preselected minimum and maximum),

the trailing edge always moves exactly the same distance from trip finger 2 to a position in registry "edge passes any predetermined point along the path of motion, such as either at the trip finger l or the trip finger 2 or any other point, and end when the trailing edge reaches the second folding point. That time delay readily may be determined by the amount of charge initially given to the capacitance 213, as determined by the voltage divider in its charging circuit, and the value of the resistance through which that charge is permitted to be dissipated. 4

No actual time delay is really necessary for the production of the second fold at the proper place according to the method now being described, because the trip device may be located in registry with the second folding device, so as to cause the production of the second fold simultaneously with actuation of the trip device which controls it. For example, if the first fold is produced at a point located one-third of the length of the article from its trailing edge, that part of the article which passes down through rolls I3, 58, is of double thickness and the second fold is produced as the original leading edge of the article registers with folding blade 15. So, if the trip device for the second fold is located in registry with folding blade 15, it may be sensitive to the thickness of the article, instead of to its mere presence, being actuated as the original leading edge (now the trailing edge of the double thickness portion of the 'article) passes the trip device.

Also, by appropriate adjustment, the second fold may be produced at a point located approximately one-third of the length of the articl from its trailing edge, and also a short distance, say an inch or a fraction thereof, short of its original 14 leading edge. In that case the second fold is produced while both parts of the double thick ness portion of the article moving into position for the second fold are still supported by rolls I3, 58, and the original first third of the article will not drop down for lack of support.

All of the foregoing is merely a matter of predetermination of the exact point where folds are desired and the selection of appropriate values of capacity and resistance, and the determination of whether time delay is necessary or not in the production of the second fold, according to the preselected location of the trip device for controlling it.

In the present arrangement initiation of discharge of capacity 2l3, which controls the second fold and which was charged instantaneously when both trip fingers I, 2 were interrupted by the article, begins when the trailing edge Passes trip finger 2. The discharging circuit for capacitance H3 is as follows: from the lower plates of capacitance 2i3 by way of conductor 3", arm of switch 20! in its 1' position, conductor 318, armature 2H) now in its b position, conductor 329, resistance 330, conductor 33l and conductor 332 to the upper plates of said capacitance. As soon as the capacitance H3 is fully discharged, the trailing edge of the article has registered with the folding blade 15, and at that moment the potential of the grid circuit of valve D reaches the critical control value, its plate circuit becomes conductive, relay 22l is energized, armature 222 moves to its a position, and the circuit through conductors 3 l5, M6 to the operating solenoid BI is energized, causing the folding blade 15 to advance and introduce the article between the second pair of folding rolls 58, 33 for the production of the second cross fold.

The folding blade 15 remains in its advanced position until the next article to be folded. engages trip 2 and recompletes the charging circuits for capacitance 2|3 before described.

In considering the circuits effective for producing the first and second folds in the one-thirdtwo-thirds typ of fold,- it will also be observed that simultaneously with energization of operating solenoid for producing the first fold, the operating solenoid I25 which trips the latch mechanism controlling the lifting plate 93 also is energized. The result is that each time a first cross folding operation is initiated at the folding rolls [3, 58 a complete cycle of operations of the lifting plate 93 i initiated andproceeds to completion, as before described.

One-half-one-quarter fold I The same control mechanism shown in Fig. 14 is usable for the production of the one-halfone-quarter type of fold, by leaving switch Ola in its closed position and moving switch 200 to its intermediate position M. Description of this variation may be simplified without the necessity of retracing all circuits completely, as follows:

In this case the arm of switch 203 is on a blank contact, so that capacitance 2l2 is entirely omitted from the circuits. Capacitance 2 is used for producing the half fold, and capacitance 2| 3 for producing the quarter fold. The arm of switch 202, also in its intermediate position M, by bridge 202a and conductor 333 shorts out the resistor 326, when that is necessary. The arm of switch 20 l in a similar position, includes armature 205 in the circuit by way of conductor 334.

The two condensers 2, H3, are charged when the trips I and 2 are in contact with the conduct- 15 ing plate 32. The charging circuit for condenser 2 is from its lower plate through conductors 32!, Ill, armature 200 in b position, conductor 3| I, potentiometer 220, secondary 2ll, point 312,

conductor 30!, conductor 3", cathode and grid of I tube C to the upper plate of condenser 2i I. The charging circuit for condenser 2" is from its lower plate through conductor 3H to the switch 20!, from the center point M of said switch through conductor 330, armature 200 in b position, conductor 3 l 3, potentiometer 2 I 3, secondary 2, point 312, conductor 300, conductor 320, cathode and grid of tube D to the upper plate of the condenser.

When the moving article intercepts both trips I and 2, both of the condensers 2, H3 begin to discharge. Condenser 2H discharges through conductors 32! and 3! 0, armature 203 in a position, conductor 323, resistors 324, 325 and 320, armature 200 in a position, conductor 32! back to the condenser. Condenser 2" begins to discharge through conductor 3", switch 20l, conductor 334, armature 203 in a position, resistors 330 and 331, conductor 330, armature 206 in a position, conductor 332 back to condenser 2l3.

When the trailing edge of the article passes trip 1, relay 200 is deenergized and the armatures 205 and 200 drop to b position. These respectively short out resistors 326 and 331. The balance of the charge in condenser 2 now dis charges through resistors 32! and 325, conductor 333, switch 202 and armature 205 in b position, completing the timing for the half fold, and that operation is performed. At the same time the balance of the charge in condenser 213 is being discharged through resistor 330, conductor 333, and armature 200 in 12 position. When this discharge is completed the quarter fold operation is performed.

When the trailing edge of the article passes trip 2 both condensers are again recharged for the next operation, which proceeds as before when another article engages the trips.

Single cross fold at mid-point The same circuits just described for use in producing the half-quarter type of fold may be made effective for producing a single cross fold at the mid-point by simply opening the switch am in the circuit to the second operating solenoid for folding blade 15, as a consequence of which it is impossible to produceoperation of the second folding blade. However, in the system shown in Fig. 14 the arm of switch 20l accomplishes the same purpose. If the switch 200 is moved to its extreme left position the switch elements 202, 203 are substantially unaffected, because th L and M contacts of switch 202 are bridged, and each of the L and M contacts ofswitch 203- is a blank contact. The arm of switch 201, however, is moved to its contact L and introduces a conductor 300, into the circuit, the operation of which is as follows: when the circuits are closed and the system made operative, a charging circuit is immediately set up for capacitance 2l3 as follows: .from'the lower plates of said capacitance by conductor 3" to the arm of switch 20!, by

conductor 30 to the voltage divider 2l3, thence 4 to the point "2 and by way of conductors 305 and 320 and the cathode-grid circuit of valve D to the upper plates of the capacitance. This charging circuit, it will be observed, does not include any of the armatures of the relays 204 or 201-, so that contact of an article with either or both of the trip fingers I, 2, produces no effect upon spective functions.

. l6 said charging circuit. The result is that. during all operations of the system with the switch 200 in its L position, the capacitance 2l3 remains Values of resistances and capacities Of course, it should be understood that the theory of operation underlying the controlling circuits described herein is the same as that in my copending application before referred to. Both resistances and capacities are chosen of appropriate sizes and values to perform their re- This is either a matter of mathematical calculation or, in the case of capacities, by adjusting the charge initially imposed upon each capacity, for later dissipation by increments at different rates or all at a single rate, by adjustment of one or the other of voltage dividers H3, 220 to the proper position. By such calculations and adjustments the system can be made not only to produce folds at the mid-point alone, or of the one-half-one-quarter type or of the one-third-two-thirds type, but at any intermediate points located upon articles varying in length between a preselected minimum length and a preselected maximum length in proportion according to the total length of each article. At the same time, the control mechanism not only times the production of the folds by variation in one or two time delay periods, but it also synchronizes with the production of folds in the several articles the operation of the lifting plate of the stacking mechanism, in such manner as to provide plenty of time for each advancing article to be entirely received in the stacking mechanism prior to the elevation of its lifting plate.

Other advantages of the invention will be apparent to those skilled in the art.

What I claim is:

1. A machine of the character described, including means for moving flat articles to be folded along a path, a reciprocating cross folding device located adjacent said path and having advance folding and retiring movements, stacking means arranged to stack the folded articles by additions to the bottom of the stack and including a reciprocating lifting plate having advance stacking and retiring movements, means. for delivering folded articles from the folding device into position resting upon the lifting plate, controlling means sensitive to movement of an article along said path, and operating means for the cross folding device and lifting plate having an operating connection to said controlling means controlled thereby and so timed with'reference to the folding device delivering means and lifting plate as to simultaneously initiate the advance folding movement of the folding device and the advance stacking movement of the lifting plate,

- 17 stacking and retiring movements, means for de-. livering folded articles from the folding device into position resting upon the lifting plate, controlling means sensitive to movement of an article along said path, and operating means for the cross. folding device and lifting plate having an operating connection to said controlling means controlled thereby and s0 timed with reference to the folding device, delivering means and lifting plate as to simultaneously initiate the advance folding movement of the folding device and the advance stacking movement of the lifting plate, whereby one folded article is lifted and added to the stack at the same time a following article is folded, said lifting plate operating means being also so constructed and timed with reference to the folding device and delivering means as to complete the retiring movement of the lifting plate before the succeeding folded article is delivered to it.

3. A machine of the character described, ineluding means for moving flat articles to be folded along a path, a reciprocating cross folding device located adjacent said path and having advance folding and retiring movements, stacking means arranged to stack the folded articles by additions to the bottom of the stack and including a reciprocating lifting plate having ad- 18 vance stacking and retiring movements, means for delivering folded articles from the folding device into position restin upon the lifting plate, controlling means sensitive to movement of an article along said path, operating means for the cross folding device controlled thereby, actuating mechanism for the lifting plate including a trigger device, means operatively connected to said controlling means for actuating said trigger device, said operating means and actuating mechanism being so constructed and so associated withsaid controlling means that when operated they simultaneously initiate advance folding movement of the folding device and advance stacking movement of the lifting plate, whereby one folded article is lifted and added to the stack at the same time a following article is folded, and manually operated means also connected to said trigger device and extending to the outside of the machine to a position convenient for access by the operator, whereby the operator at will can cause actuation of the lifting plate without operation of the folding device, for the purpose of advancing to stack position in the stacking means an article which otherwise might remain unstacked therein.

JOHN E. PRESTON.

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