US3329286A

US3329286A - Stabilizer arm arrangement for a case palletizer

Info

Publication number: US3329286A
Application number: US404843A
Authority: US
Inventors: Wladyslaw F Kurczak
Original assignee: Mojonnier Bros Co
Current assignee: FMC Corp
Priority date: 1964-10-19
Filing date: 1964-10-19
Publication date: 1967-07-04
Anticipated expiration: 1984-07-04

Description

STABILIZER ARM ARRANGEMENT FOR A CASE PALLETIZER Filed Oct. 19, 1964 W. F. KURCZAK July 4, 1967 2 Sheets5hee t .1

y 4, 1967 w. F. KURCZAK 3,329,285

STABILIZER ARM ARRANGEMENT FOR A CASE PALLETIZER Filed Oct. 19, 1964 as M 66 95 3 2 Sheets-Sheet z} 74 72 75 I 70 4 73; f 55 g4 In 5 92 v l I 76 90 64 90 76m 84 74 fig 8EiPf+614MZ/ I 64 J f Q0 E J30 1 1% J33 w i ii 935M lllllgl United States Patent 3,329,286 STABILIZER ARM ARRANGEMENT FOR A CASE PALLETIZER Wladyslaw F. Kurczak, Chicago, Ill., assignor to Mojonnier Bros. Co., Chicago, Ill., a corporation of Illinois Filed Oct. 19, 1964, Ser. No. 404,843 Claims. (Cl. 214-1) This invention relates generally to the materials handling art and more particularly to the loading of pallets with stacked cases of bottled beverage.

Efficient handling of cased merchandise has been advanced appreciably by the procedure of stacking the cases on pallets. Corrugated paper cartons, being rectangular parallelepipeds, are readily stacked and grouped in this fashion; and dairy product cases have been equipped with interlocking stacking lugs at the corners to promote stack stability. However, cases for bottled beverage are conventionally of only half-depth construction whereby to expose the necks of the bottles. Accordingly, a superposed case must rest on the crowns of the bottles in the directly underlying case rather than on the walls of the case itself. Wobbly stacks result, and the instability of stacked cases of bottled beverage has heretofore posed a substantial obstacle to palletizing such units. Considerable spilling of the stacks and bottle breakage has been experienced when palletizing has been attempted.

Therefore, an important object of the present invention is to provide apparatus for stabilizing stacked cases during their handling in a palletizing operation.

A more general object of the invention is to provide a new and improved palletizer arrangement for stacked cases.

Another object of the invention is to provide stabilizer apparatus for use in palletizing stacked cases of bottled beverage.

These and other objects and features of the invention will become more apparent from a consideration of the following descriptions.

Apparatus in accord with the invention includes an accumulating plate for receiving a number of vertically stacked cases. An upright frame is mounted for reciprocably slidable movement in a path across the accumulating plate and for stationary disposition adjacent one side thereof. In addition, a structure is provided on the upright frame having horizontally spaced attachment sites; and a pairof gripper arms are mounted respectively at these sites for movement toward and away from each other whereby to grip and release cases stacked therebetween. Drive means are provided for repositioning the gripper arms between a converged position gripping stacked cases for stabilizing the same and a retracted position releasing the cases and freeing the position generally between the gripper arms for transfer of succeeding, stacked case onto the accumulating plate.

The invention, both to its structure and its mode of operation, will be better understood by reference to the following disclosure and drawings forming a part thereof, wherein:

FIG. 1 is a top plan view of a palletizing arrangement incorporating case-stabilizing apparatus in compliance with the invention;

FIG. 2 is an elevational view of the apparatus of FIG.

-1 taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is an enlarged, top plan view of the case-stabilizer apparatus of FIGS. 1 and 2;

FIG. 4 is an elevational view of the apparatus of FIG. 3 taken substantially along the line 44 of FIG. 3 with the stacked cases removed;

FIG. 5 is an enlarged, partially schematic view of the control system and drive units for the case-stabilizer apparatus of FIGS. 3 and 4; and

3,329,286 Patented July 4, 1967 FIG. 6 is an enlarged and more detailed view of one of the position-responsive switches utilized in the control system of FIG. 5, taken substantially along the line 6-6 of FIG. 4.

Referring now in detail to the drawings, specifically to FIGS. 1 and 2, a palletizing arrangement is seen indicate-d generally by the numeral 20. In this arrangement, unstacked cases of bottled beverage are delivered in a train to a stacker unit 22 by a conveyor 24. The stacker unit 22 incorpoates mechanisms for elevating cases either one or two abreast to permit other cases to pass directly therebeneath to form a stack two high, subsequently lifting this stack to permit other cases to pass into alignment therebeneath forming a threehigh stack and continuing in like manner until a stack of the desired height is reached. The construction of the stacker unit 22 may be substantially such as that described in US. Patent No. 2,966,018 granted Dec. 27, 1960, to H. W. Currie; or alternatively, the construction may be of any other well known type.

The palletizing'arrangement 20 additionally includes a stack pusher or transfer unit 26 which is aligned with the conveyer 24 above the cases carried thereon. Pusher unit 26 is operative to deliver the stacked cases, illustrated in broken outline and indicated by the numeral 28, to a stationary accumulating plate 30 disposed in a horizontal position fiow-pathwise downstream from the stacker unit 22. The stack pusher unit 26 includes a pusher plate 32 which is carried on a shaft 34, the pusher unit 26 additionally including a power unit 36 which drivingly reciprocates the shaft 34 as for example by being gearingly, hydraulically or pneumatically coupled therewith. Operation of the pusher unit 26 is, of course, coordinated with the operation of stacker unit 22 using any suitable means such as for example position responsive switches and cooperative control circuitry.

The transportation of the cases of bottled beverage along the conveyer 24, through the stacker unit 22 and to the accu'mulating plate 30 defines a first path of case movement, and this path is terminated at the rest position of the stacked cases which is indicated in FIG. 1 by the numeral 38. A second path of case movement is defined transverse this first path by the alignment of a pallet magazine 40 and an exit conveyor 42 which are spaced to situate the accumulating plate 30 therebetween. The exit conveyer 42 is provided with a suitable number of freely rotatable cylinders or rollers 44 which are arranged to define a substantially horizontal bed. The conveyer unit 42 also includes a base frame 46, and the accumulating plate 30 is mounted on the base frame 46 by a pair of spaced brackets 48 which situate the accumulating plate above the bed defined by the cylinders 44, as is indicated in FIG. 2. The distance that the accumulating plate 30 is spaced above the bed which is defined by the cylinders 44 is selected to be sufficiently greater than the height of a pallet 50 to pass the same freely therebeneath.

A gantry 52 is slidably disposed between the pallet magazine 40 and the accumulating plate 30 to cooperate in moving the-stacked cases from the accumulating plate onto an underlying pallet. The gantry 52 includes spaced, pendent legs 54, each of which carries a pair of suitably journaled wheels 56. As is well shown in FIG. 2, the base frame 46 of the exit conveyer 42 is fashioned with horizontally extending, upper and lower guidetracks 58 which open laterally to receive a pair of the wheels 56. The gantry 52 also includes a horizontally disposed top plate 60, and an upright frame 62 is securely mounted and braced at the end of the plate 60 which is closest the stacks of cases on the accumulating plate 30. At its upper end, the frame 62 includes a transverse bar or structural element 64 which, in compliance with the invention, is provided with

spaced attachment sites

66 and 68 as is best shown in FIG. 1. In further compliance with the invention, a pair of

gripper arms

70 and 72 are mounted respectively at the

sites

66 and 68 for movement toward and away from each other for gripping and releasing cases stacked therebetween. Specifically, the

attachment sites

66 and 68 comprise pivots having vertical axes, and the

arms

70 and 72 are swingably mounted thereto.

The

gripper arms

70 and 72 together with their associated elements comprise a case-stabilizing apparatus; and turning to FIGS. 3 and 4 for a more detailed description in this regard, the

gripper arms

70 and 72 are seen to be fabricated as bifurcated members, each of which is provided with verticallyspaced knuckles 74. cooperatively, each of the

pivots

66 and 68 Comprises a vertical pin 76 which is received in the central bore of the associated knuckles 74 and in a sleeve bearing 78 which is situated interjacent the knuckles 74 to surround the pin 76. Furthermore, a gripper bar 80 is securely fastened to the outer ends of each of the

gripper arms

70 and 72, the bars 80 being disposed vertically and having a length sufficient to contact at least two vertically adjacent cases in a stack of the same. In accordance with a feature of the invention, resilient surface means are provided on the bars 80 at least in the areas in which they contact the cases. In the specific embodiment illustrated in the drawings, these surface means comprise tubular elements 82 of a resilient polymeric substance. One suitable substance for the elements 82 is a copolymer of vinyl chloride and vinyl acetate. Elastomeric compositions may also be employed.

The

gripper arms

70 and 72 are intended to be powered in their swinging movement through respective horizontal arcs, and

pneumatic jacks

84 and 86 are provided for this purpose. Each of the

jacks

84 and 86 includes a cylinder 88 which is swingably mounted to the horizontal bar 64 by means of a bracket 90. Each of the

jacks

84 and 86 also includes an extensible and retractable piston rod 92 which is pivotally mounted to the inner end of the corresponding gripper arms by means of a clevis arrangement 94, as is best shown in FIG. 3. The

pneumatic jacks

84 and 86 are regulated by control means for repositioning the

gripper arms

70 and 72 between a converged position gripping stacked cases whereby to stabilize the same and a retracted position releasing the cases and freeing the path along the edge of the upright frame 62, as will be described more fully hereinafter.

It was stated earlier herein that the stacked cases 28, once they have been deposited on the accumulating plate 30, are subsequently shifted laterally in the direction of exit conveyor 42 and onto and underlying pallet 50. Returning to FIGS. 1 and 2, a transfer mechanism indicated generally by the numeral 96 is seen aligned generally with the path in which the pallets 50 move from the magazine 40 to the exit conveyor 42. Numerous types of transfer mechanisms may be employed in this regard; and in the illustrated embodiment, a long-stroke pneumatic jack having an extensible and retractable piston rod 98 is employed. The pallet magazine 40 includes a rollable underbed comprising one or more parallel disposed sequences of rotatably journaled cylinders or rolls 100; and the piston rod 98 has a head or bumper plate 102 afiixed to its free end for driving the lowermost pallet 50 from the magazine 40, along the rollable underbed thereof and to a position partially underlying the accumulating plate 30. With particular reference to FIG. 1, the bumper plate 102 is seen to extend laterally of the piston rod 98 to terminate at its opposite ends in drive fingers 104 which are joined to the bumper plate by means, such as overriding clutches 106, which serve to keep the fingers in laterally extended position for contacting the legs 54 of gantry 52 whereby to transport the same. However, clutches 106 are of a type that declutches upon encountering a selected resistance whereby to permit folding of the fingers to a retracted position wherein they may pass the legs 54 in a direction generally toward the exit conveyer 42.

While the pallets 50 are arranged to be transported toward the exit conveyer 42 in a number of steps corresponding to the number of rows of stacks of cases which the pallet is to carry, the gantry 52 is only intended to be reciprocated in a horizontal path corresponding in length to the distance required for delivering a stack of cases from the accumulating plate and onto a pallet disposed adjacent the accumulating plate on the exit conveyer 42. Therefore, a stop plate 108 is mounted on the exit conveyer frame at a suitable position to abut and limit moyement of the gantry in the exit direction. A cooperating return jack 110 is mounted on the exit conveyor frame for use in returning the gantry to a position freeing the accumulating plate in front of the stacker unit 22. Advantageously, a stop 108 and a return jack 110 are provided on each lateral side of the exit conveyer frame for balanced action.

It is recognized that many other arrangements for transferring the pallets and the stacked cases in the direction of the exit conveyor may be employed.

The pneumatic circuit for controlling the operation of the gripper arm drive jacks 84 and 86 will now be described with principal reference to FIG. 5. There, a pneumatic control circuit indicated generally by the numeral 112 is seen to include a pilot valve 114 of the double-bleed type. The pilot valve 114 receives inlet air from a supply conduit 116 and passes exhaust air through an exit conduit 118, a silencer unit 120 being advantageously incorporated in the exhaust line. A branched conduit 122 connects the pilot valve 114 with the rod-ends of the

jacks

84 and 86, and a similar branched conduit 124 connects the blind ends of the

jacks

84 and 86 with the pilot valve 114. As will be appreciated from an inspection of FIG. 5, the

jacks

84 and 86 are thus connected in parallel fluid circuit. A T fitting 126 is connected between branched conduit 124 and the pilot valve 114 to establish a circuit through a conduit 128 between the conduit 124 and an auxiliary pilot valve 130 which is advantageously spring-biased into a normally open condition. A second connection between the

pilot valves

114 and 130 is established by a stub conduit 132.

Operation of the circuit 112 is desirably controlled by position responsive switch means. Therefore, a position responsive switch 134 is connected to pilot valve 114 by a conduit 136, and a position responsive switch 138 is connected to auxiliary pilot valve 130 by a conduit 140. Turning for the moment to FIG. 2, the position responsive switch 134 is seen to be mounted to a leg 54 of the gantry 52 for coaction with a trip device 142, trip device 142 being mounted in stationary position relative to the frame of exit conveyer 42 as for example by being secured to the stop plate 108. Similarly and with reference to FIGS. 4 and 6, the position responsive switch 138 is mounted on the top plate 60 of gantry 52, switch member 138 being arranged with a depending, swingable actuator arm 144. Actuator arm 144 is positioned to contact the lowermost case in the stack of cases on the accumulating plate in order to actuate the switch 138. Returning to a consideration of FIGS. 4 and 6, the actuator arm 144 is seen to be mounted for rotation about a horizontal shaft 146, shaft 146 being secured betwen a pair of upright brackets 148 and arm 144 being welded to an annular collar 150 which receives the shaft 146.

The position responsive switch 138 also includes a valve member 152 which is mounted to the top plate 60 by a bracket 154. The valve member 152 includes a balltype valve element 156, element 156 being disposed for contact by the actuator arm 144. In accordance with well known practices, the valve member 152 includes a compression spring, not shown, which biases the valve element 156 in an outward direction for closing the valve. Correspondingly, contact of the element 156 by the arm 144, in a pressuring manner .so as to overcome this biasing spring, permits the escape of control fluid from the valve member 152. If desired, the position responsive switch 138 may also include a compression spring 158 operatively disposed between the top plate 60 and the actuator arm 144 for biasing the actuator arm generally away from the valve member 152.

Similarly, the position responsive switch 134 includes, as is shown in FIG. 5, a valve member 160 which is mounted to the leg 54 of gantry 52 by a bracket arrangement 162. The valve member 160 includes a ball-type element 164 which is adapted to be abutted by a spring biased plunger 166 of the trip device 142.

Having thus described one construction of the invention, it will be advantageous now to describe how the illustrated embodiment operates.

Assuming that the gantry 52 is in its retracted position clearing the accumulating plate 30 and assuming that the

gripper arms

70 and 72 are also retracted so as to clear the space above the accumulating plate, the accumulating plate being empty of stacked cases, actuation of the transfer unit 26 so as to extend the shaft 34 wil initiate the cycle. As the shaft 34 advances, pusher plate 32 will contact two previously assembled stacks of cases in the stacker unit 22. Further advance of the shaft 34 will deliver these two stacks of cases onto the accumulating plate and into the position shown in solid outline in FIG. 1. Next, the transfer device 96 will be actuated to extend the piston rod 98 and advance the bumper plate 102 toward the lowermost pallet 50 in the magazine 40. Continued advance of the bumper plate will cause this lowermost pallet 50 to pass beneath the upper plate 60 of gantry 52 and beneath the accumulating plate 30; and as this pallet emerges from beneath the accumulating plate, moving in the general direction of exit conveyer 42, the drive fingers 104 will engage the legs 54 of the gantry to begin the advance of the gantry with the simultaneous emergence of the pallet from beneath the accumulating plate.

As the gantry 52 advances toward the stacked cases 28, the actuator arm 144 will eventually contact the lowermost case in the stack to actuate the control circuit 112. In its rest condition, the circuit 112 is arranged to deliver control air to the rod ends of the

jacks

84 and 86 so as to position the

gripper arms

70 and 72 in their retracted or diverged condition where they free the space above the accumulating plate permitting delivery of the stacked cases thereon from the stacker unit 22. In this rest condition of the circuit 112, the pilot valve 130 is in its normally open condition delivering control air to the position responsive switch 138 which is correspondingly in its normally closed condition. When the actuator arm 144 is urged into contact with the stacked cases that are positioned on the accumulating plate, this arm is pivoted about the shaft 146 and into engagement with the element 156 of valve 152. The resultant movement of the element 156 opens the valve 152 to permit the control air to escape. This exhausting of control air through the valve of the position responsive switch 138 releases the back pressure on pilot valve 114 so as to produce a shift in the position of the operator element of that valve whereby to redirect control air from the rod ends to the blind ends of the

jacks

84 and 86, correspondingly exhausting the rod ends of these jacks. Resultant movement of the piston rods 92 urges the

gripper arms

70 and 72 into converged relationship clamping the stacked cases therebetween. At the same time, the operator element of pilot valve 114 shifts so as to deliver control air through the conduit 132 repositioning the operator of pilot valve 130 closing that valve, terminating flow to the position responsive switch 138 and permitting subsequent realignment of the operator of pilot valve 114 even through the actuator arm 144 is not released.

As the pallet transfer device 96 completes its stroke toward exit conveyor 42, the position responsive switch 134 will engage the trip device 142 whereby to open the valve member 160 permitting control air to escape therefrom and releasing the back pressure on the pilot valve 114. This release of the back pressure produces a shift in the operator of the pilot valve, reconnecting the air inlet with the rod ends of the

jacks

84 and 86 and exhausting the blind ends of these jacks. As a consequence, the piston rods 92 are withdrawn to retract the

gripper arms

70 and 72 into their diverged condition releasing the stacked cases and clearing the space in front of the gantry 52. This repositioning of the operator in pilot valve 114 closes the conduit 132 permitting pilot valve 130' to return to its normally open position. The transfer unit 96 will also initiate its return stroke at this time to relieve the actuator arm 144 from the pressure of the stacked cases as the return jack drives the gantry back toward the pallet magazine. When the pallet transfer device 96 is retracted and when the return jack 110 reaches the end of its stroke, the cycle is completed and the accumulating plate 30 is cleared for receipt of a second group of stacked cases from the stacker unit 22.

As will be recognized from the foregoing descriptions, the present invention provides apparatus for stabilizing stacked cases during their handling in a palletizing operation. Operation of the

gripper arms

70 and 72 holds the stacked cases in clamped relationship while they are being transferred from the accumulating plate to the pallet emerging from beneath that plate. Moreover, the resilient tubular elements 82 on the gripper arms; produce a firm, resilient clamping action on the stacked cases. While the invention is useful for various types of stacked cases, it will be recognized that it is of particular value when stacked cases of bottled beverage are to be palletized, the action of the gripper arms serving to stabilize the naturally wobbly stacks of cases of that type.

The specific example herein shown and described is to be considered as being primarily illustrative. Various changes beyond those described will, no doubt, occur to those skilled in the art; and such changes are to be understood as forming a part of this invention insofar as they fall within the spirit and scope of the appended claims.

The invention is claimed as follows:

1. For use in a palletizing arrangement, case-stabilizing apparatus comprising: first transfer means for moving stacks of cases in a selected path; structure means disposed at the end of said path and having horizontally spaced attachment sites and straight bar means between said sites; a pair of gripper arm means mounted respectively at said sites for movement toward and away from each other for gripping and releasing cases stacked therebetween in alignment with said straight bar means; drive means for powered repositioning said arm means between a converged position gripping stacked cases for stabiliz ing the same and a retracted position releasing said cases and freeing said selected path for transfer of succeeding, stacked cases along said selected path; second transfer means contacting said structure means for moving the same in a path transverse said selected path; and control means for operating said drive means to hold said arm means in converged position during the forward stroke of said second transfer means for stabilizing the gripped cases and to retract said arm means upon initiation of the return stroke of said second transfer means for releasing said gripped cases.

2. In apparatus for palletizing cases, the combination comprising: platform means disposed horizontally for receiving a plurality of vertically stacked cases; first transfer means aligned with said platform means for moving stacks of cases thereon in a selected path; upright frame means mounted for reciprocably slidable movement in a path across said platform means transverse said selected path and for stationary disposition adjacent one side of said platform means; structure means on said frame means having horizontally spaced attachment site; a pair of gripper arm means mounted respectively at said sites for movement toward and away from each other for gripping and releasing cases stacked therebetween; drive means for repositioning said arm means between a converged position gripping the stacked cases for stabilizing the same and a retracted position releasing said cases and freeing said selected path for transfer of succeeding, stacked cases onto said platform means; and second transfer means contacting said upright frame means for moving the same in said transverse path, said drive means operating to hold said arm means in converged position during the forward stroke of said second transfer means for stabilizing the gripped cases and said drive means acting to retract said arm means upon initiation of the return stroke of said sec-nd transfer means for releasing said gripped cases.

3. In apparatus for palletizing cases, the combination comprising: platform means disposed horizontally for receiving a plurality of vertically stacked cases; first transfer means aligned with said platform means for moving stacks of cases thereon in a selected path; upright frame means mounted for reciprocably slidable movement in a path across said platform means transverse said selected path and for stationary disposition adjacent one side of said platform means; structure means on said frame means having horizontally spaced attachment sites; a pair of gripper arm means mounted respectively at said sites for movement toward and away from each other for gripping and releasing cases stacked therebetween; drive means for repositioning said arm means between a converged position gripping the stacked cases for stabilizing the same and a retracted position releasing said cases and freeing said selected path for transfer of succeeding, stacked cases onto said platform means; second transfer means contacting said upright frame means for moving the same in said transverse path; and control means for operating said drive means to hold said arm means in converged position during the forward stroke of said second transfer means for stabilizing the gripped cases and to retract said arm means upon initiation of the return stroke of said second transfer means for releasing said gripped cases.

4. In apparatus for palletizing cases, the combination comprising: platform means disposed horizontally for receiving a plurality of vertically stacked cases; first transfer means aligned with said platform means for moving stacks of cases thereon in the selected path; upright frame means mounted for reciprocably slidable movement in a path across said platform means transverse said selected path and for stationary disposition adjacent one side of said platform means; structure means on said frame means having horizontally spaced pivots; a pair of gripper arm means mounted respectively at said pivots for swingable movement toward and away from each other for gripping and releasing cases stacked therebetween; a pair of fluid-actuated jack means connected to said structure means and individually to one of said arm means, for repositioning said arm means between a converged position gripping stacked cases for stabilizing the same and a retracted position releasing said cases and freeing said selected path for transfer of succeeding, stacked cases onto said platform means; second transfer means contacting said upright frame means for cyclicly moving the same in said transverse path; and control means for operating said jack means to hold said arm means in converged position during the forward stroke of said second transfer means for stabilizing the gripped cases and to retract said arm means upon initiation of the return stroke of said second transfer means for releasing said gripped cases, said control means including valve means, conduit means connecting said jacks in parallel fluid circuit with each other and in circuit with said valve means, and position responsive switch means connected in circuit with said valve means for sensing the cyclic position of said frame means and operating said valve means in accordance therewith.

5. Apparatus according to claim 1 which further comprises resilient surface means covering said arm means for firmly gripping the cases stacked therebetween.

References Cited UNITED STATES PATENTS 2,227,346 12/1940 Holrn 19824 2,776,742 1/ 1957 Langenberg 19824 2,821,317 1/1958 Locke 294-106 3,054,515 9/1962 Nawman 214-6 3,093,252 6/1963 Cahill 214-16 FOREIGN PATENTS 974,946 11/1964 Great Britain.

GERALD M. FORLENZA, Primary Examiner,

HUGO O. SCHULZ, Examiner.

J. E. OLDS, Assistant Examiner.

Claims

2. IN APPARATUS FOR PALLETIZING CASES, THE COMBINATION COMPRISING: PLATFORM MEANS DISPOSED HORIZONTALLY FOR RECEIVING A PLURALITY OF VERTICALLY STACKED CASES; FIRST TRANSFER MEANS ALIGNED WHITH SAID PLATFORM MEANS FOR MOVING STACKS OF CASES THEREON IN A SELECTED PATH; UPRIGHT FRAME MEANS MOUNTED FOR RECIPROCABLY SLIDABLE MOVEMENT IN A PATH ACROSS SAID PLATFORM MEANS TRANSVERSE SAID SELECTED PATH AND FOR STATIONARY DISPOSITION ADJACENT ONE SIDE OF SAID PLATFORM MEANS; STRUCTURE MEANS ON SAID FRAME MEANS HAVING HORIZONTALLY SPACED ATTACHMENT SITE; A PAIR OF GRIPPER ARM MEANS MOUNTED RESPECTIVELY AT SAID SITES FOR MOVEMENT TOWARD AND AWAY FROM EACH OTHER FOR GRIP PING AND RELEASING CASES STACKED THEREBETWEEN; DRIVE MEANS FOR REPOSITIONING SAID ARM MEANS BETWEEN A CONVERGED POSITION GRIPPING THE STACKED CASES FOR STABILIZING THE SAME AND A RETRACTED POSITION RELEASING SAID CASES AND FREEING SAID SELECTED PATH FOR TRANSFER OF SUCCEEDING, STACKED CASES ONTO SAID PLATFORM MEANS; AND SECOND TRANSFER MEANS CONTACTING SAID UPRIGHT FRAME MEANS FOR MOVING THE SAME IN SAID TRANSVERSE PATH, SAID DRIVE MEANS OPERATIG TO HOLD SAID ARM MEANS IN CONVERGED POSITION DURING THE FORWARD STROKE OF SAID SECOND TRANSFER MEANS FOR STABILIZING THE GRIPPED CASES AND SAID DRIVE MEANS ACTING TO RETRACT SAID ARM MEANS UPIN INITIATION OF THE RETURN STROKE OF SAID SECOND TRANSFER MEANS FOR RELEASING SAID GRIPPED CASES.