US2792967A - Container denesting and feeding mechanism - Google Patents

Description

May 21, 1957 c. H. DIXON 2,792,967

CONTAINER DENESTING AND FEEDING MECHANISM Filed Feb. 27, 1952 9 Sheets-Sheet 1 STAPLER UNIT FILLING UNIT 5 BREAKER 4 FEEDING H (II-{IT 30 JNVENTOR.

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CONTAINER DENESTING AND FEEDING MECHANISM Filed Feb. 27. 1952 9 Sheets-Sheet 5 INVENTOR. .Charle; H- uran BY 3 a M-1Q lf alga.

May 21, 1957 c. H. DIXON CONTAINER DENESTING AND FEEDING MECHANISM 9 Sheets-Sheet 6 Filed Feb. 27; 1952 7. I9 I80 I82 IN V EN T OR. Charles H. D

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CONTAINER DENESTING AND FEEDING MECHANISM Filed Feb. 27, 1952 9 Sheets-Sheet 7 INVENTOIIR. Charles H. DLxon May 21, 1957 c. H. DIXON CONTAINER 'DENESTING AND FEEDING MECHANISM Filed Feb. 27, 1952 9 Sheets-Sheet 8 INVENTQR Charles H. Dlxon BY Mi MM l w.

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CONTAINER DENESTING AND FEEDING MECHANISM Filed Feb. 27, 1952 9 Sheets-Sheet 9 INVENTOR Charles H. 012mm United States Patent CONTAINER DENESTING AND FEEDING MECHANISM Charles H. Dixon, Detroit, Mich., assigpor to E x-Cell-Ct Corporation, Detroit, Mich., a corporation of Michigan Application February 27, 1952, Serial No. 273,719

Claims. (Cl. 221-210) The present invention relates to a machine for filling expendable containers made of waxed paper or the like, and more particularly to a mechanism in such a machine for feeding containers from a stack into the machine.

The general object of the invention is to provide a mechanism for withdrawing longitudinally tapered paper containers one by one from a stack of nested or partially telescoped containers, orienting the withdrawn containers, and feeding the oriented containers into a machine for performing further operations with and on the containers.

A further object is to provide a container denesting and feeding mechanism of the above described character which makes provision for utilizing compressed air to separate the individual containers from the stack.

Another object is to provide a container feeding mechanism which is positive in operation and entirely automatic.

Further objects and advantages of the invention will appear from the following description of an illustrative embodiment of the invention, taken with the accompanying drawings, in which:

Figure 1 is a general side or longitudinal elevational view of a container filling machine including a container denesting and feeding mechanism constructed in accordance with the invention.

Fig. 2 is a front elevational view of the filling machine showing further details of the mechanism for unstacking and feeding the containers.

Fig. 3 is a fragmentary front view of the feeding mechanism drawn on a larger scale than Fig. 2.

Fig. 4 is a sectional plan view of the feeding mechanism taken along the line 44 in Fig. 3.

Fig. 5 is a fragmentary bottom view taken along the line 5-5 in Fig. 3.

Fig. 6 is a sectional View taken along the line 6-6 in Fig. 3 transversely of a magazine for holding a stack of containers.

Fig. 7 is a fragmentary plan sectional view taken along the line 7-7 in Fig. 6 showing details of a dog adjusting arrangement.

Fig. 8 is a fragmentary sectional view taken along the line 88 in Fig. 3 and showing details of container gripping means and a container transporting slide.

Fig. 9 is a transverse sectional view taken along the line 9-9 in Fig. 3.

Fig. 10 is an elevational view of the container transporting slide taken as indicated by the line 1010 in Fig. 9.

Figs. 11 to 16 are fragmentary diagrammatic views showing successive stages in the operation of the container gripping means. In Fig. 11 the container is being grasped. In Fig. 12 the container is being withdrawn from the stack. In Fig. 13 the container has been withdrawn and is about to be released. Figs. 14, 15 and 16 show successive stages of the container releasing operation, and Fig. 16 also shows a container ejecting action.

Fig. 17 is an enlarged sectional view of the container gripping means taken generally along the line 17--17 in Fig. 8. y

Z79|2,96'7, Fatented May 21, 1957 Figs. 18 to 21 are a series of fragmentary diagrammatic views showing successive stages in the cooperation of the container gripping means with hook means for sup porting the stack of nested containers. In Fig. 18 the container stack has been lifted away from the hook means and the hook means are about to be swung outwardly. In Fig. 19 the hook means are being swung outwardly and in Fig. 20 the hook means are swung to their outermost position, wherein they are latched. In Fig. 21 the hook means are about to be unlatched for engagement with the next container in the stack.

While the invention is susceptible of various modifications and alternative constructions, there is shown in the drawings and will herein be described in detail the preferred embodiment, but it is to be understood that it is not thereby intended to limit the invention to the form disclosed, but it is intended to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

A feeding mechanism in accordance with this invention is shown in Figs. 1 and 2, embodied as a feeding unit 30 of a machine 31 for filling downwardly tapered waxed paper containers 32 with milk or the like. In this instance, the, containers 32 are of a known type (see Fig. 3), having a scored upper or mouth portion 34 adapted to form a gable type closure. The scored portion 34 includes a pair of scored sides or panels 35 adapted to be folded inwardly, as well as two other opposite walls or panels 36 provided with tabs or flaps 37 protruding upwardly beyond the scored panels 35. The containers are tapered downwardly to facilitate nesting them in compact stacks for shipment.

The feeding unit 30 is operative to withdraw the coutainers 32 one by one from a stack of nested containers. The stack may be formed by means of the mechanism disclosed and claimed in my copending application Serial No. 338,404, filed February 24, 1953, for Container Nesting Method and Mechanism or by means of the mechanism disclosed and claimed in the copending application of James F. Earp, Serial No. 250,170, filed October 6, 1951 for Container Nesting Mechanism, and now Patent No. 2,736,149.

The feeding unit 30 is operable to deposit the containers on a conveyor 40 which may be of the type described in Patent No. 2,368,483, issued January 30, 1945, to Charles Z. Monroe, to which reference may be had for a more complete understanding. Briefly, the conveyor 40 in this instance includes a pair of rails 41 along which the containers 32 are slid in upright position by means of three parallel synchronously operated conveyor chains 42, 44 and 45. Appropriate means (not shown) may be provided for adjusting the elevation of the rails to accommodate various sizes of containers, such as halfpints, pints, and quarts. Spaced paddles 46 are secured to the conveyor chain for confining and guiding the containers during their movement along the conveyor. The containers are introduced into the conveyor chain by means of a vertical pusher 48 which is reciprocated periodically along the rails by means of an appropriate mechanism (not shown).

By means of the conveyor 40, the containers are carried into a breaker unit 50 which performs an initial closing operation by breaking the scores in the scored upper portions 34 of the individual containers. Further move ment along the conveyor brings the containers into a filling unit 51 wherein they are filled with the desired contents, such for example as fluid milk. The scored upper portions 34 of the containers are then formed into gable type closures by a closing unit 52, and the closures are stapled by a stapler unit 54. At the end of the conveyor 40, a sealing unit 55 seals the containers and applies a date stamp.

support for the various units' of the machine. The filling unit 38 is supported on a heavy bridge member'62 which is connected between the upright members at and 61.

The bridge 62 has an arm or projection 64 which is inclined upwardly to the left as viewed in Fig. 2. The arm 64 is of boxlike construction to form an elongated recess 65 open toward the front. An elongated slide bar 66 is bolted to the inclined arm so as to span the recess 65 from end to end, the bar being parallel with the arm and thus being inclined at about 60 to the vertical. The slide bar 66 is rectangular in crosssection and is positioned with one of its flat faces directed forwardly. A container receiving magazine or guide 68 is clamped to the upper end of the slide bar so as to be longitudinally adjustable'thereon. In this instance, the magazine includes a pair of lower angle members or rails 69 and7tl, extending the full length of the magazine to provide a lower support for a stack of the containers 32. At the right hand end of the magazine, as viewed in Fig. 2, is a pair of upper angle guides 71 and 72 having outwardly flared flange portions 74 attheir left hand ends to facilitate the insertion of the containers into the magazine.

' The lower angle members 69 and are supported by a lower clamping bracket 75 having a horizontal arm 76 to which the angles are bolted. In similar fashion, the upper angle guides 71 and 72 are supported by an upper clamping bracket 78 having a horizontal arm 79 to which the angles are bolted. The lower and upper brackets 75 and 78 are fastened together by bolts 80 and 81, and together the brackets define a rectangular recess '82 which fits over the front surface and the top and bottom edges of the slide bar 66. The brackets 75 and 78 are retained on the bar by means of a pair of clamping bars 84 and 85 secured to the brackets respectively by means of bolts 86 and 87 and clamped against the rear surface of the bar. The front angles 70 and 72 are spaced by a pair of connecting bars 89. A suitably formed splash guard 96 is bolted to the upper supporting bracket 78 to protect the containers in the magazine from contaminatron.

The stack of containers is supported at its lower end by movable means, comprising in this instance a pair of hooks 94 and 95 mounted on the lower magazine bracket 75, one hook 94 being disposed forwardly and the other hook 95 being disposed rearwardly of the magazine. The hooks are rotatably mounted by means of pivots 96 and 98-extending generallyat right angles to 'the magazine rails 69 and 70 and journaled in upwardly pro ecting bosses 99 and 100 formed on the lower magazine bracket75. 'The hook pivots are located adjacent the lower ends of the magazine railsv 69 and .76, and the hooks extend downwardly of the magazine and beyond the lower end thereof. The hooks terminate with inturned end portions 101 and 102 which are adapted to hook over the edge of the scored mouth portion 35 of the lowermost container in the stack. As clearly shown in Fig. 5, the hooks% and 95 and the pivots 96 and 98 are hollow or tubular to provide air passages 104.

The hooks are operable in unison between inward or stack engaging positions and outward or stack disengaging positions. Concerted operation of the hooks is effected in this instance by means of inwardly extending arms 105 and 106 secured to the hook pivots 96 and 98 and connected for joint movement by means of a pin 108 on the arm 1115 and a longitudinal slot 189 in the arm 106. The hooks are biased toward their inward or stack engaging positions by means of a tension coil spring 110 connected between the pin 108 and an anchoring screw 111 on the lower magazine bracket 75.

A rearwardly extending hook operating arm 112 is 7 formed integrally with the arm 106. Provision ismade for latching the stock supporting hooks 94 and 95 in their outward or stack disengaging position by means of a latch 114 mounted on a pivot 115 journaled in the lower magazine bracket 75 and extending generally parallel to the hook pivots 96 and 98. The latch pivot 115 is positioned upwardly of the magazine from the hook pivots, and the latch 114 extends downwardly of the magazine. The latch is provided with a latching shoulder or ledge 116 facing toward the latch pivot 115 and extending generally at right angles to the radial axis of the latch, the ledge being engageable with the end of the arm 112 When'the hooks are in their outward positions. Spaced farther out from the latch pivot 115 than the ledge is alateral cam lobe 118 having oppositely inclined inner and outer camming surfaces 119 and 120. The latch is biased toward the arm 112 by means of a contractile spring 121 connected between the latch and the arm.

The feeding unit 30 includes means for. periodically moving the stack supporting hooks 94 and 95 outwardly away from the container stack preliminary to withdrawing the lowermost container from the stack. in this instance, the hooks are operated by a movable container transporting member, preferably taking the form of a slider or crosshead 132 which is reciprocable along the slide bar 66 toward and away from the container magazine 68. A pin is mounted on the slider for periodically moving the hook-operating arm 112 leftwardly and deflecting thelatch 114 outwardly by engaging the cam lobe 118. The pin 130 is secured to the slider 132 for adjustment longitudinally thereof by means of a supporting member or'bar 134 extending leftwardly from the slider and fastened theretoby means of a pair of bolts 135 extending through longitudinally disposed slots 136 in thebar. A longitudinally adjustable stop screw 137 is provided to facilitate the adjustment of the pin support 134.

Compressed air is supplied to the air passages 104 in the hooks'94 and 95 under the control of an air valve 138, for the purpose of separating the lowermost container from the container stack despite any adhesions which may have formed therebetween. The air valve is operable by a roller 139 mounted on the slider-reciprocating chain. The roller is positioned on the chain to: open the air valve near the beginning of the down stroke of the slider just as the pin 130 is unlatching the latch 114 to release the stack engaging hooks 94 and 95.

.The slider 132 is preferably of two-piece construction to facilitate removal of the slider from the slide bar 66. In this instance the slider 132 includes a front member or body 140 slidable along the front surface of the bar 66 and a rear'shell 141 extendingaround the rear surface I and the edges;of the'bar, the rearrshell 141 and the body 140 being bolted together. An adjustable gib 142 is interposed between the rear shell and the top edge of the bar to provide an adjustment of the playbetween the slider and the bar.

The slider 132 isreciprocable along the bar 66 by suit able means,- preferably including a driving chain 14-5 running on a'pair of'sprockets 146 and 148 spaced longitudinally of the slide bar 66. The sprockets are rotatable on stub shafts 149 and 150 mounted on the inclined arm 64 ofithe. bridge 62 and extending generally at right angles to the bar 66 so that to chain runs in a plane generally parallel with the bar. The chain 145 is connected; to the slider 132 by means of a laterally projecting pin 151 carried by the chain and journaled in a block 152 which is slidable transversely of the slide bar in the slider132. The'block 152 is slidably received in a rearwardly. facing groove 155 formed in the rear shell 141, the block being retained in'the groove 155 by means of retaining plates 156.

. Thechairi-145 is driven-in suitable fashion, preferably by'meansof drive "chains: and 161. The chain 169 instance by a pin or dowel rod 215 secured to the sprocket 162 and on a sprocket I66 mounted on a main drive shaft 168. In this instance, the main shaft 168 is driven by a motor 169 (Fig. 1) which is connected to the shaft by means of reduction gears 170 and a drive chain 171.

The feeding unit includes container gripping means which in this instance takes the form of a gripper head 175 carried by the container transporting slider 132. As shown in Fig. 8, the gripper head is connected to the slider by means of a rockshaft 176 which is secured to the gripper head and rotatably mounted in a cylindrical projection or boss 178 oriented on the slider generally at right angles to the slide bar 66, the boss being provided with a suitable bearing sleeve 179 in which the rockshaft is journaled. In the course of the cyclical movement of the slider or movable member 132, the gripper head is oscillated between container withdrawing and discharging positions by means which preferably includes a crank arm 180 secured to the inner end of the rockshaft. A cam following roller 181 is mounted on the outer end of the crank arm by means of a crank pin 182. The roller is confined in a groove or cam track 184 formed in the slide bar 66. The slider is provided with a recess 183 to house the crank. For the greater part of its length,

the groove extends parallel to the longitudinal axis of the slide bar, but at its right hand or lower end, the groove curves upwardly, generally at right angles to the slide bar and thus terminates in an upturned portion 185. The

groove is operative to rock the gripper head between its normal position, with the roller 181 in the longitudinal portion of the groove and with the head oriented to withdraw the lowermost container axially of the container stack, and a rotated position with the roller in the upturned portion 185 of the groove and the container carried by the gripper head oriented in a generally upright position.

In the illustrated embodiment, the gripper head 175 includes a gripper body 190 which provides support for a mechanism to carry out a cycle of alternately gripping and ejecting individual containers. For this purpose, a pair of stationary jaws 191 and 192 is mounted on the gripper body 198. The jaws are provided with planar inwardly facing gripping surfaces 194 and 195 which are normally oriented parallel to the slide bar 66. Inwardly facing beveled surfaces 196 and 197 on the jaws provide means for alining the containers with the gripping surfaces 194 and 195. Positioned in cooperative relationship to the stationary jaws 191 and 192 is a pair of movable jaws 199 and 280 carried on pivots 281 and 282 mounted on the gripper body 190 inwardly of the gripping surfaces 194 and 195 and extending parallel thereto. Situated on the jaws, outwardly of the pivots and adjacent the gripping surfaces, are respective curved camming surfaces 204 and 205 which recede radially in a leftward direction as seen in Fig. 17. Torsional springs 206 and 207 are provided to bias the jaws 199 and 200 in a direction to carry the camming surfaces 204 and 205 leftwardly so that the highest portions of the cam surfaces are normally immediately adjacent the stationary gripping surfaces 194 and 195. The movable jaws 199 and 200 have respective pairs of overlapping tails or arms 209 and 210 which extend inwardly of the pivots 201 and 282. The jaws 199 and 200 are preferably of identical construction, but one jaw is turned end for end with respect to the other.

The movable jaws 199 and 200 are operated in this which is engageable with the tails 209 and 210 of the jaws. The jaw operating rod 215 is oriented generally parallel to the gripping surfaces 194 and 195 and is guided at its ends for movement longitudinally of the gripper head 175 by longitudinal grooves 217 and 218 inthe gripper body 190.

In the illustratedembodiment, the jaw operating rod 215 is reciprocable by means of a curved two-armed actuating lever or bell crank 220 oscillably mounted on the gripper body 190 by means of a pivot shaft 221 oriented generally at right angles to the slide barr66. The lever 220 is connected to the jaw operating rod 215 by suitable means, preferably including a link or yoke 222 having a stem portion 224 at one end and a pair of forked arm portions 225 at the other end. The jaw operating rod 215 extends through a. suitable aperture 226 in the stem portion, and the forked arm portions are connected to the lever 220 by means of an elongated dowel rod 228 extending through an aperture 229 in the lever and journaled in suitable bushings 230 mounted in the forked arms 225, the lever being positioned between the arms. The dowel rod 228 is oriented generally parallel to the lever pivot 221. At both ends, the rod 228 extends outwardly of the gripper body 190 through suitable longitudinal slots 232 therein, the slots being dimensioned to provide clearance for arcuate movement of the dowel rod 228. A tension coil spring 234 is con nected between one end of the rod 228 and an anchor post 235 on the gripper body 190, in order to bias the lever 220 and the link or yoke 222 in a direction to move the jaw operating rod 215 away from the tails 209 and 210 of the jaws. The rockshaft 176 serves as a stop for the yoke 222.

In addition to the container gripping means, the gripper head preferably includes container ejecting means which in this instance comprises a pair of U-shaped ejecting levers 248 and 241 operable by the bell crank 220. Each of the ejecting levers 240 and 241 has a pair of arms 245 which normally extend upwardly of the slide bar 66 toward the container magazine 68. The arms 245 on each lever are interconnected by a base portion 246. The ejecting levers are oscillable on pivots 243 and 244 connected to the ejecting levers near opposite ends of the respective base portions 246 thereof. The pivots are mounted generally parallel to the crank rod 228 on either side of the gripper head. The ejecting levers 240 and 241 are biased into retracted positions by torsional springs 249 which tend to swing the base portions of the levers downwardly of the slide bar 66. The retracting movement of the ejecting levers is limited by a pair of stop pins 258 and 251 mounted on the gripper body for engagement by the base portions 246 of the levers.

In order to provide for operation of the ejecting levers 240 and 241 by the bell crank or operating lever 220, the dowel rod 228 carried by the bell crank extends outwardly thereof far enough in both directions to engage the respective ejecting levers. However, the ejecting levers are positioned a substantial distance forwardly of the dowel rod 228 when the rod is in its retracted position. This spacing provides lost motion between the dowel rod and the ejecting levers to permit the movable gripping jaws 199 and 208 to be opened by the bell crank 220 before the ejecting levers are engaged by the rods 228.

As the slider approaches the end of its upstroke the gripper head 175 is operated by means which preferably includes a dog or pawl 260, dependingly pivoted by means of a pivot bolt 261 to an adjustable support 262 secured to he inclined arm 64 of the bridge 62. The dog is positioned to operate the bell crank 220, which in this instance includes an upper arm 265 carrying a roller 266 and a lower arm 268 carrying a flat, generally radial abutment or pad 269. The dog is positioned in the path which the roller traverses as the slider is reciprocated. The dog has a nose portion 270 including an inclined camming edge 271 which deflects the roller on the upstroke of the slider, the roller being deflected in a direction to open the gripping jaws 199 and 280. A torsional spring 275 is provided for biasing the dog in a direction to carry the nose portion of the dog upwardly of the slide bar 66. The movement of the dog under the influence of the biasing spring is limited by a stop pin 276 mounted on the adjustable support.

Provision is made for adjusting the timing of the operation of the gripper head on the upstroke of the slider. For this purpose the feeding unit is provided in this inarena-oer stance with. adjustingmeans 280 for shiftinggthe position for-securing the adjustable support 262 to the inclined Forwardly of the rear pivot bolt 281 armof the bridge. is an eccentric 282 mounted on a pivot stud 284 and positionedin a longitudinalslot 285 in the adjustable support. The eccentric is. provided with a wrench head 286 for rotatingthe eccentric in order to swing the adjustable support;longitudinally of the slide bar on the rear pivot belt 281. A lock nut 287. is threaded on the stud 284 for the purpose oflocking the eccentric in an adjusted position. The gripper head 175 is operable near the end of the downstroke of the slider by means of an adjustable stop 290 which isthreadedthrough a boss or pillar 291 on the slider. ...The stopis positioned for engagement by the padon the bell crank 22% after the gripper head 175 has been rotated approximately 90by the entry of the crank 180 into the upturned portion 185 of the groove 184 in the slide bar 66.

The feeding unit is provided with a plurality of arcuate rails 295 for guiding the containers as they are being rotated into upright positions by the gripper head 175. An

' inclined bracket or ramp 296 is provided for guiding the ..bottoms of the containers on to the conveyor rails. A

- paddle 298 is mounted on one side of the gripper head 175 to steady the ejected container.

The feeding unit 30 is prepared for operation by inserting astack of nested containers into the upper end of the magazine 68. The containers are positioned in the magazine mouth downwardly, and they slide by gravity down the magazinerails 69 and 70 until the edges of the scored closure panels 35 engage the stack supporting hooks 94 and 95, which arrest further downward movement of the stack.

Inoperation, the slider operating chain 145 is driven continuously at a constant speed. The laterally projecting pin 151 carried by the chain 145 reciprocates the slider 132 back and forth along the slide bar 66. While the slider operating pin is passing around the sprockets 146 and 143, the block 152 moves in the transverse groove 155 in the slider.

As the slider 132 approaches the end of its upstroke, the gripper head 175 is operated so as to grasp the lowermost container. in the stack. The container grasping operation is initiated when the roller 266 engages the inclined camming edge 271 on the dog 260. The dog deflects the roller downwardly as shown in Fig. 11 so that the bell crank or control lever 220 is oscillated clockwise on its pivot. Arcuate movement is thereby imparted to the dowel rod 22% carried by the lower arm of the bell crank. By means of the connecting link or yoke 222 the dowel 228 moves the jaw operating dowel rod 215 in the guiding slots 217 and 218. The dowel 215 engages the tails 299 and .210 of the jaws 199 and 200 'and thereby rotates the jaws in a direction to bring the receding portions of the camming surfaces 204 and 205 of the jaws opposite the gripping surfaces 194 and 195 on the stationary jaws 191 and 192. Thus the effect of the deflection of the lever 2211 by the dog is to open the movable jaws 199 and 200. Clearance is thereby afforded for the entry of the protruding flaps 37 on the paper container into the spaces between the stationary jaws 196 and 197 Y and the movable jaws 199 and 200. i

The dog deflects the lever 220 a sufficient distance to open the jaws 199 and 200, but not sufficiently to move the ejecting levers 24d and 241 to any appreciable extent. The wide spacing between the ejecting levers and the dowel 228 permits the jaws to open before the dowel engages the ejecting levers.

As the upstroke of the slider continues, the roller 266 1 passes over the dog, and the jaw operating lever 220 returns to its initial position (Fig. 11) under the impetus of the lever return spring 234. The jaws, thus released, are closed upon the container flapsby the jaw. return tsprings206and-207.

When the container'flaps enter the'spacessbetweenthe stationary-jaws 191v and 192 and the movable jaws .199

and 200, the edges of the scoredclosure panels35 onithe lowermost containerengage the projecting legs 245 of the ejecting levers 240 and 241. During the remaining portion of the .upstrokeofthe slider 132' the ejecting levers lift the entire stack of containers positioned in the magazine 68. This has the effect of disengaging the mouth of the lowermost container from the stack supporting hooks 9d and (Fig. 18). 'The hooks are then swung outwardly away from the container stack by the pin carried by the slider 132. The pin operates the hooks by engaging and oscillating the arm 112 as shown in Figs. 5 and 19. When the hooks have been swung out a suflicient distance to clear the container stack, the latch operating spring 121 moves thelatch 114 so as to hook the latching shoulder 116 overthe end of the arm 112 (Fig. 20). The hooks arethus latchedin their outward position to permit descent of the stack when theslider commences its downstroke.

On the downstroke of the slider 132, the gripper head 175 pulls the lowermost container downwardly of the slide bar 66. After the mouth of the lowermost container has passed the points of the hooks 94 and 95, the hook operating pin 131) on the slider engages the camming surface 119 on the latch (Fig. 21). The pin 130 thereby deflects the latch out of engagement with the arm 112 so that the hooks 94 and 95 are released for inward movement under the impetus of the hook return spring 110. The points of the hooks 94 and 95 compress the scored closure panels 35 of the lowermost container andhook over the mouth of the next or second container. The stack is thus arrested by the hooks while the lowermost container is being withdrawn from the stack by the continuing downward stroke of the slider 132.

The feeding unit provides means whereby an air blast may optionally be employed to aid in the separation of the lowermost container from the stack.

As previously indicated, the containers are ordinarily made of waxed paper, and adhesions occasionally develop between adpacent containers in the nested stack. This is likely to occur most frequently when the stacks of containers have been subjected to comparatively high temperatures during shipment. In accordance with this feature of the invention, the air valve 138 of the feeder unit 30 is operated by the roller 139 onthe chain at approximately the same time as the hooks are being unlatched by the pin 130 for movement back into their stack engaging position. Compressed air is thereby supplied to the air passages 104 in the hollow hooks 94 and 95 and the resulting air blast issuing out of the points of the hooks channels a path between the lowermost container and the next container in the stack. The air blast thereupon builds up pressure between the lowermost container and the remainder of the stack, and the pressure is effective to separate the lowermost container from the stack without tearing or otherwise damaging the separated container.

On the downstroke of the slider 32, the dog 260 ratchets over the roller 266 as shown in Fig. 12, the dog being deflected by the roller without moving the lever 220. The

gripper head withdraws the lowermost container axially of the stack for the greater part of the downstroke of the slider 132. During this portion of the downstroke, the crank roller 181 is riding in the longitudinal portion of the groove 184 in the slide bar 66. After the container has been withdrawn a sutiicient distance to clear the stack, the crank roller 181 is deflected upwardly into the upturned portion 185 of the groove (Fig. 13). The upward-deflection of the roller 181 rotates the crank and the rockshaft 176 which supports the gripper head 175. In this way the gripper head 175 and the container carried thereby are rotated from a position coaxial with the stack toward a position in which the container is upright.

t it is being rotated toward its upright position. In this instance, the releasing operation is initiated when the flat radial pad 269 on the jaw operating lever 2201engages with the adjustable stop 290 on the slider 132. The continuing rotation of the gripper head 175 provides relative rotation between the lever 120 and the gripper head. Releasing movement of the jaws 199 and 200 begins when the dowel rod 215 engages the tails 209 and 210 of the jaws as shown on Fig. 14. In Fig. 15 the jaws have been rotated a sufiicient distance so that their grip on the container has been released. However, the containers, being made of waxed paper, may adhere to the stationary jaws 191 and 192 or the movable jaws 199 and 200. Consequently the lever 220 is given a further relative movement with respect to the gripper head 175 so that the dowel rod 228 engages and rotates the ejecting levers as shown in Fig. 16. In this case, the ejecting levers act against the edges of the scored closure panels of the container so as to push the container downwardly away from the gripper head 175. The container thereupon falls by gravity clear of the gripper head and comes to rest in upright position upon the conveyor rails 41. The ramp or bracket 296 guides the bottom of the container on to the rails and the paddle 298 on the gripper head steadies the container to prevent its tipping.

During the initial portion of the upstroke of the slider 132 the gripper head 175 is rotated back to its normal position by the cooperative action of the crank roller 181 and the groove 184 in the slide bar 66. The container 32 which has been deposited on the conveyor rails 41 is introduced into the conveyor chains 42, 44, and 45 by the pusher 48 while the feeding unit 30 is completing another cycle of grasping, withdrawing, and feeding a container.

The distance which the container stack is lifted oil? the supporting hooks 94 and 95 is adjustable by loosening the clamping plates 84 and 85 and sliding the magazine supporting brackets 75 and 78 along the slide bar 66. Since the hooks 94 and 95 are mounted on the magazine this adjustment shifts the relative position of the hooks and the upper end of the stroke of the gripper head 175.

The point in the upstroke of the slider 132 at which the gripping jaws 199 and 200 are opened to receive the lowermost container may be adjusted by rotating the eccentric 282 to shift the position of the adjustable support 262 for the dog 260. The point in the upstroke at which the hooks 94 and 95 are swung outwardly away from the container stack may be adjusted by shifting the support 134 for the pin 130 longitudinally of the slider 132.

The ejecting action of the gripper head 175 is adjustable by shifting the position of the threaded stop 290 on the slider 132. The position of the stop determines the point in the downstroke of the slider at which the lower arm of the lever 220 is arrested by the stop.

I claim as my invention:

1. In a mechanism for feeding individual containers successively from a stack of containers, the combination comprising an inclined container magazine to receive the container stack with the containers oriented mouth downwardly, a slider supported for reciprocation toward and away from the lower end of the magazine and generally parallel thereto, means for reciprocating the slider, stack supporting means at the lower end of the magazine movable between a normal stack supporting position and a stack disengaging position, a gripper head pivoted on the slider for rotation between a container withdrawing position and a container discharging position, means operable by the slider to move the stack supporting means into stack disengaging position as the slider approaches the end of its upstroke, container grasping means on the gripper head for grasping the lowermost container of the stack, the stack supporting means thereupon being returned to normal position in supporting relationship to the remainder of the stack, means for rotating the gripper head from its container withdrawing position to its container discharging position as the slider approaches the lower end of its downstroke, and means for releasing the container grasping means at the end of the downstroke.

2. In a mechanism for withdrawing containers from a stack, the combination comprising a downwardly inclined container magazine, a slide bar mounted generally parallel to the magazine and extending downwardly therefrom, a container transporting slider reciprocable on the slide bar, driving means to reciprocate the slider, a pair of stack supporting hooks mounted on the magazine for movement into and out of stack supporting position, a

gripper head pivoted on the slider for rotation between a container withdrawing position and a container delivering position, means on the gripper head operative to raise the container stack in the magazine clear of the stack supporting hooks on the upstroke of the slider, means operable by the slider to move the stack supporting hooks out of their stack engaging position after the stack has been raised, latching means to retain the stack supporting hooks in their stack disengaging position, a pair of gripping jaws on the gripper head to grasp the lowermost container in the stack, a lever on the gripper head to open the jaws, a pawl pivoted in fixed relationship to the slide bar for operating the jaw lever near the end of the upstroke of the slider, the pawl being arranged to ratchet over the lever on the downstroke of the slider, means operable by the slider for unlatching the stack supporting hooks near the beginning of the downstroke of the slider, the stack supporting hooks being thereby released for movement into stack supporting relationship with the second container in the stack, air passages in the stack supporting hooks for directing a blast of air between the lowermost and the second containers to separate the lowermost container from the stack, means operative near the end of the downstroke of the slider to rotate the gripper head into container discharging position, a stop on the slider engageable by the jaw lever upon rotation of the gripper head toward the container discharging position for releasing the container held by the gripper head, and a pair of container ejecting levers operable by the jaw lever for positively ejecting the container from the gripper head.

3. In a mechanism for Withdrawing tapered containers from a container stack, the combination comprising a guide for positioning the stack with the containers oriented mouth downwardly, movable stack supporting means engageable with the mouth of the lowermost container and mounted for movement between stack engaging and stack disengaging positions, yieldable means urging the stack supporting means into its stack engaging position, a container withdrawing member movable cyclically to ward and away from the lowermost container, a gripper on the withdrawing means for grasping the lowermost container, operating means on the container withdrawing means for operating the stack supporting means, means operable by the operating means for moving the stack supporting means into container disengaging position as the lowermost container is being grasped by the withdrawing means, a latch to retain the stack supporting means in stack disengaging position, and means on the latch operable by the operating means on the stack withdrawing means for releasing the stack supporting means for movement into supporting engagement with the second container in the stack.

4. In a mechanism for withdrawing tapered containers individually from a container stack, the combination comprising a guide for positioning the stack with the containers oriented mouth downwardly, a stack-supporting hook engageable with the mouth of the lowermost container and movable between stack engaging and stack disengaging positions, container withdrawing means for grasping the lowermost container, means operable by the container withdrawing means for moving the hook II means into stack disengaging position, means for subse- 1 quent1y-returning the hook ,1 means sinto stack-e engaging position in supporting relationship withzvtheiumouthtaof the. second containerinthe stack, and-air passagelmeans in the hook means for directingair between the'lowermost and second containers to separate the' lowermost container from the stack.

' the lower end of the stack, means for moving the hooks inwardly toward opposite sidesnof the lowermost .con-

tainer so that the hooks engage the mouth of the'second .container to arrest the stack as the'lowermost container is being withdrawn by the grasping means, air passages in the hooks to direct air between the lowermost containerand the second container to separate the lowermost 12 containe1 =:rom-;theiistack, andanairwalve to -admit air to the air-passages asthe hookssmove into engagement withthe stack.

References Cited in the file of. this patent UNITED'STA-TES PATENTS 1,330,639 Leumann Feb. 10,-,1920 1,722,048 Hill July 23, 1929 1,864,008 Wright et al. June 21, 1932 1,927,151 Blasco "Sept. 19, 1933 1,959,327 Adams May 22, 1934 1,979,089 Adams -Oct. 30, 1934 2,002,213 Adams, May 21, 1935 2,017,521 Whiting Oct. 15, 1935 2,301,892 Lewis Nov. 10, 1942 2,325,164 Goodwin July 27, 1943 2,413,446 1 Glassner -sDec. 31, 1946 2,551,476 Vantlander May 1, 1951

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