Method and apparatus for boxing bag stacks

Abstract

A method of boxing bag stacks supported on U-shaped wickets having the wicket cross-member on one side of the bag stack, including supporting a bag stack by grasping both the cross-member and the bag stack other end from the other side of the bag stack, moving the supported bag stack into a container, and releasing the bag stack in the container. An axially extending carrier includes a grasper on one axial end and is selectively extendable in a generally radial direction for selective engagement with the wicket cross-member from the other side of the bag stack. A grasping mechanism on the other axial end of the carrier extends in the generally radial direction to selectively grasp the bag stack other end.

Description

TECHNICAL FIELD

[0001] The present invention is directed toward transporting bags, and particularly toward moving bags between a production line and transportation containers.

BACKGROUND OF THE INVENTION

[0002] Bags such as plastic bags are, of course, widely used in virtually every segment of the marketplace today. In many instances (e.g., plastic bags used for packaging bread and other products), the bags are typically manufactured on special equipment and then placed in stacks upon wickets for delivery to the producer of the product, who may have their own equipment which will handle the bags stacked upon wickets.

[0003] A wicket is a generally U-shaped wire device having a cross-member secured at opposite ends to two spaced apart arms or legs that are arranged to be received in holes formed in the top section of the bags. The legs and cross-member of the wickets may in one configuration generally lie in a plane. Alternatively, “Hartmann” type wickets are sometimes used, which wickets include offsetting legs between the legs and the cross-members, whereby the cross-member does not lie in the same plane as the legs. Back and front boards may also optionally be secured over the wicket legs on opposite sides of the stack of bags to provide a front and back support for the bags disposed on the wicket. When a desired number of bags have been loaded upon the legs, rubber grommets are placed over the legs to hold the stack in place.

[0004] Apparatus for automatically loading bags on wickets are disclosed, for example, in U.S. Pat. Nos. 5,522,690, 5,738,478, 5,911,553 and 6,273,663 B2. Each wicket may support, for example, 250 or 500 bags in a stack, which stacks are typically conveyed between stations for various types of quality inspections. U.S. Pat. No. 6,149,377, the disclosure of which is hereby fully incorporated by reference, discloses an apparatus which may be used to convey such stacks.

[0005] After inspections are completed at the manufacturing plant, it is desirable to move the stacks of bags into containers in which they may be stored and transported to the ultimate user (e.g., a bakery making bread). Moreover, when placed in the containers, it is desirable to orient the wicket legs so that they will lie relatively flat within the container. If they are pointed in a generally vertical direction when in the container, they may damage bags in the adjacent stacks and also will prevent the bag stacks from being compactly positioned against one another for efficient use of the container. Further, even if the legs are oriented at an angle from the vertical direction when placed in the container, if the legs are oriented in a direction which projects beyond the top end of the bags, they may abut the container end, in which case they may ultimately damage the container end and/or may be prevented from laying as flat as desired and therefore even in that orientation prevent the bag stacks from being compactly positioned against one another for efficient use of the container.

[0006] Of course, one method which may be used to ensure that the wicket legs are properly oriented in the containers is to have a worker manually place the bags in the container and, when doing so, ensure that the wicket is properly oriented. Even if the bag stacks are transported from the final inspection stations to the containers mechanically, a worker may be assigned to watch over the process and manually adjust any wickets which do not end up in the proper orientation when placed in a container. However, it will be appreciated that assigning a worker to such a task can be extremely cost inefficient.

[0007] Therefore, one process which has been used which does not require oversight by a worker has been to mechanically place the bag stacks in the container (e.g., using an automatic mechanical carrier which grasps both ends of the bag stacks) and, after releasing the bag stack in the carrier, sweeping a tool over the bag stack from its top end to its bottom end to tend to pull the upper bags of the stack away from the top end of the bag stack. This can cause the bag stack to move so that, when viewed from the side, it changes from a generally rectangularly shaped stack to a parallelogram shape with the ends of the stack tilted toward the bottom end of the bag stack (e.g., leaning to the right with the wicket on the left end). Such a shape correspondingly causes the wicket to lean along with the bag stack, with the wicket legs thereby oriented in the desired direction for compact stacking of multiple bag stacks in a container. Unfortunately, it has been found that this operation will not always reliably orient the wicket in the desired direction. For example, it will not reliably orient “Hartmann” type wickets. Further, where the bags do not have gussets in their bottom ends (i.e., where the bags are no thicker on the bottom ends than the rest of the bags), sweeping the tool over the bags does not reliably cause the stack to move to a parallelogram shape as is necessary to orient the wicket legs as desired.

[0008] The present invention is directed toward overcoming one or more of the problems set forth above.

SUMMARY OF THE INVENTION

[0009] An apparatus for, and method of, boxing bag stacks are provided, in which the cross-member of the wicket supporting the bags is on one side of the bag stack and is engaged from the opposite side whereby both ends of the bag stacks may be grasped from the opposite side and then placed in a container with the wicket reliably positioned to provide compact stacking of multiple bag stacks in the container.

[0010] In one aspect of the present invention, a method of boxing a bag stack supported on one end by wicket legs connected by a cross-member on one side of the plurality of bags is provided, including the steps of supporting the bag stack by grasping both the cross-member and the bag stack other end from the other side of the bag stack, moving the supported bag stack into a container, and releasing the bag stack in the container.

[0011] In one form of this aspect of the invention, the step of supporting the bag stack by grasping the cross-member from the other side of the bag stack comprises extending a grasper from the other side of the bag stack to grasp the cross-member.

[0012] In another form of this aspect of the invention, prior to supporting the bag stack by grasping the cross-member, the wicket may be supported on a support whereby the wicket legs tilt upwardly and at least a portion of the wicket cross-member is clear of blockages therearound, with the cross-member portion supported on the support grasped, and the wicket then removed from the support. In a further form, the wicket may pivot down about the wicket cross-member when removed from the support, with the wicket legs blocked to retain the plurality of bags on the legs after downward pivoting of the wicket resulting from the removing step. In still further forms, the blocking step may include locating stops beneath the wicker legs during the removing step, and the stops may be located to be engaged by the wicket legs to temporarily support the legs in a non-vertical position after the removing step.

[0013] In still another form of this aspect of the invention, the step of moving the supported bag stack into the container comprises moving the bag stack whereby the bag stack one side faces the bottom of the container.

[0014] In yet another form of this aspect of the invention, the step of supporting the bag stack by grasping both the cross-member from the other side of the bag stack comprises supporting the bag stack by supporting the leg ends, carrying the leg ends to a support, releasing the leg ends to support the cross-member on the support with the cross-member spaced from the plurality of bags, and extending a grasper from the other side of the bag stack and engaging the grasper with a side of the cross-member facing the plurality of bags. In this form, the cross-member of the wicket may be spaced from the bags on the wicket legs whereby the weight of the bag stack causes the wicket legs to be oriented downwardly after the step of releasing the leg other ends. Also, grasping the cross-member during the step of supporting the bag stack may include engaging the cross-member with a grasper on a side facing the other end of the bag stack. Further, the step of supporting the bag stack may generally direct the other ends of the wicket legs toward the bag stack other end. Still further, the plurality of bags may be supported in a non-vertical orientation when releasing the leg ends.

[0015] In another aspect of the invention, a method of boxing a bag stack is provided. The bag stack has a first thickness and a plurality of bags each having a pair of holes at one end receiving legs of a U-shaped member. The U-shaped member legs are connected at one end by a cross-member and have a length greater than the first thickness with a retainer on the other ends of the legs adapted to maintain the bags on the legs. The method includes the steps of supporting the bag stack by supporting the leg other ends of the U-shaped member, carrying the leg other ends of the U-shaped member to a support, releasing the leg other ends to support the cross-member of the U-shaped member on the support, supporting the bag stack by grasping the bag stack other end and grasping the cross-member, moving the supported bag stack into a container, and releasing the bag stack in the container.

[0016] In one form of this aspect of the invention, the step of releasing the leg other ends causes the cross member of the U-shaped member to be positioned beyond the one ends of the plurality of bags. In this form, the step of releasing the leg other ends may cause the U-shaped member to pivot about the cross-member, and may further comprise pulling the other end of the plurality of bags.

[0017] In another form of this aspect of the invention, the cross-member of the U-shaped member is spaced from the bags on the U-shaped member legs whereby the weight of the bag stack causes the U-shaped member legs to be oriented downwardly after the step of releasing the leg other ends.

[0018] In still another form of this aspect of the present invention, grasping the cross-member during the step of supporting the bag stack comprises engaging the cross-member with a grasper on a side facing the other end of the bag stack. In this form, the step of releasing the bag stack may comprise moving the grasper toward the other end of the bag stack.

[0019] In yet another form of this aspect of the present invention, the step of supporting the bag stack generally directs the other ends of the U-shaped member legs toward the bag stack other end.

[0020] In another form of the invention, the cross-member is on one side of the bag stack and the leg other ends project from the other side of the bag stack, and the supporting the bag stack is performed by grasping the bag stack other end and grasping the cross-member from the other side of the bag stack.

[0021] In still another form, the plurality of bags are supported in a non-vertical orientation when performing the step of releasing the other leg ends. In this form, the step of carrying the leg other ends of the U-shaped member to a support may include sweeping the bag stack upwardly over a surface, and the step of supporting the bag stack in a non-vertical orientation supports the plurality of bags at an angle of 40 to 50 degrees relative to vertical.

[0022] In yet another form, the retainer comprises grommets on the other ends of the legs.

[0023] In still another aspect of the present invention, a method of boxing a plurality of bag stacks such as described above is provided, including the steps of (a) grasping the leg other ends of the U-shaped member of a bag stack, (b) carrying the leg other ends of the U-shaped member of the first bag stack to a support, (c) releasing the grasped leg other ends to support the cross-member of the U-shaped member and allow pivoting of the U-shaped member about the supported cross-member, (d) grasping both the bag stack other end and the cross-member from one side of the bag stack, (e) moving the grasped bag stack into a container, (f) sensing when said grasped bag stack may be released, (g) releasing the bag stack into the container, and (h) repeating steps (a) through (g) with additional bag stacks for the container until it is determined that no more bag stacks should be placed in said container.

[0024] In one form of this aspect of the invention, additional bag stacks are released into the container in alternating orientations with one end of a subsequent bag stack adjacent the other end of the underlying bag stack.

[0025] In another form of this aspect of the invention, step (c) causes the cross member of the U-shaped member to be positioned beyond the one ends of the plurality of bags. In this form, step (c) may cause the U-shaped member to pivot about the cross-member, and may also include pulling the other end of the plurality of bags.

[0026] In still other forms of this aspect of the invention, the cross-member of the U-shaped member may be spaced from the bags on the U-shaped member legs whereby the weight of the bag stack causes the U-shaped member legs to be oriented downwardly after the step of releasing the leg other ends, and/or step (c) causes the other ends of the U-shaped member legs to be generally directed toward the bag stack other end. Further, the cross-member may be on one side of the bag stack with the leg other ends projecting from the other side of the bag stack, with step (d) performed by grasping the bag stack other end and grasping the cross-member from the other side of the bag stack.

[0027] In yet another form of this aspect of the invention, step (d) includes engaging the cross-member with a grasper on a side facing the other end of the bag stack. In further forms, step (g) may include moving the grasper toward the other end of the bag stack.

[0028] In still other forms of the invention, step (c) includes supporting the plurality of bags in a non-vertical orientation. In further forms, step (b) may include sweeping the bag stack upwardly over a surface, and/or step (c) may include supporting the plurality of bags at an angle of 40 to 50 degrees relative to vertical. Further, where a removable retainer retains the plurality of bags on the U-shaped member legs, the non-vertical orientation of the plurality of bags may leave a gravity pulling force of Z in the direction of the U-shaped member legs, where Z is less than the force required to remove the retainer from the U-shaped member legs.

[0029] In yet another aspect of the present invention, a carrier is provided for a bag stack supported on one end by wicket legs connected by a cross-member on one side of the plurality of bags. The carrier extends along a generally axial direction, is adapted to selectively carry the bag stack oriented in the generally axial direction, and includes a grasping mechanism on one axial end and a grasper on the other axial end. The grasping mechanism extends a generally radial direction from the axial direction for selectively grasping the bag stack other end, and the grasper is selectively extendable in the generally radial direction for selective engagement with the cross-member in an extended position.

[0030] In one form of this aspect of the invention, the grasper has a surface facing axially away from the grasping mechanism and adapted to selectively mate with the cross-member.

[0031] In another form of this aspect of the invention, a drive selectively moves the grasping mechanism and the grasper axially relative to one another.

[0032] In still another form of this aspect of the invention, a robot is secured to the carrier to selectively move the carrier.

[0033] In yet another form of this aspect of the invention, the grasping mechanism is radially movable to grasp a bag stack other end and pivotally movable away from the bag stack other end to release the bag stack other end from the grasping mechanism.

[0034] In another form of this aspect of the invention, the cross-member is on one side of the bags, and stops are selectively positionable beneath the U-shaped member legs on the other side of said plurality of bags.

[0035] In still another aspect of the present invention, a bag stack carrier is provided which extends along a generally axial direction and is adapted to selectively carry the bag stack oriented in the generally axial direction. The carrier includes a supporting mechanism on one axial end of the carrier and adapted to selectively support the other leg ends of the U-shaped member in a generally radial direction from the axial direction. A grasping mechanism on the other axial end of the carrier and extending in the generally radial direction is adapted to selectively grasp the bag stack other end. A grasper has a surface adapted to selectively mate with the cross-member of the U-shaped member, where the mating surface faces axially away from the grasping mechanism.

[0036] In one form of this aspect of the invention, a robot is secured to the carrier to selectively move the carrier.

[0037] In another form of this aspect of the invention, the grasping mechanism is radially movable to grasp a bag stack other end and pivotally movable away from the bag stack other end to release the bag stack other end from the grasping mechanism.

[0038] In still another form of this aspect of the invention, a support is adapted to hang the bag stack from the cross-member of the U-shaped member. In this form, the support may support the cross-member of the U-shaped member for pivoting about its longitudinal axis, and/or the support may be aligned with the plurality of bags.

[0039] In yet another form of this aspect of the invention, a supporting table may be provided at an angle to vertical for supporting the bag stack hanging from the support in a non-vertical orientation. In this form, the supporting table may define a plane of a supporting surface, with the support supporting the cross-member of the U-shaped member above the plane of the supporting surface. Further, the supporting table may be selectively adjustable to different orientations relative to vertical, including (1) at an angle of 40 to 50 degrees relative to vertical and/or (2) at an angle which supports Y weight of the bag stack hanging from the support, where the removable retainer requires a force of X to remove it from the U-shaped member legs and the plurality of bags weigh less than X+Y.

[0040] In another form of the invention, the grasping mechanism includes a plurality of spaced fingers extending in a generally axial direction and the supporting table includes a plurality of matching slots in its lower end whereby the grasping mechanism fingers are adapted for radial movement between the supporting table slots to grasp a bag stack other end supported on the supporting table.

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 is a side view of a carrier usable with and embodying the present invention;

[0042] FIG. 1a is a partial view of the carrier taken along line 1a-1a of FIG. 1;

[0043] FIG. 2 is a front view of the carrier of FIG. 1;

[0044] FIG. 3 is a top view of a bag stack which may be carried by the carrier of FIGS. 1-2;

[0045] FIGS. 4-11 are side views of a carrier, guide rail and support table showing a sequence of operation according to the present invention, where:

[0046] FIG. 4 illustrates the carrier picking up a bag stack from a guide rail;

[0047] FIG. 5 illustrates the carrier moving the bag stack to the support table;

[0048] FIG. 6 illustrates the carrier grasping the lower end of the bag stack;

[0049] FIG. 7 illustrates the bag stack when placed on the support of the support table;

[0050] FIG. 8 illustrates the carrier moving away from the bag stack after releasing the wicket legs;

[0051] FIG. 9 illustrates the bag stack supported on the wicket cross-member engaged by the carrier top grasper;

[0052] FIG. 9a is a detailed cross-sectional view showing the carrier top grasper engaging the wicket cross-member;

[0053] FIG. 10 illustrates the carrier fully supporting the bag stack for movement to a container; and

[0054] FIG. 11 illustrates the carrier after placing a bag stack in a container, with the container shown in cross-section;

[0055] FIG. 12 illustrates a wagon supporting the wicket of a bag stack, which wagon may be used in conjunction with an alternative embodiment of the present invention;

[0056] FIG. 13 is a top view of the wagon and supported wicket of FIG. 12;

[0057] FIG. 14 is a side cross-sectional partial view of an carrier of the alternative embodiment used with the wagon and supported wicket and bag stack of FIGS. 12-13;

[0058] FIG. 15 is a side cross-sectional view similar to FIG. 14 but showing the wicket after it has been removed from the wagon; and

[0059] FIG. 16 is a front view (taken from the left side of FIG. 14) of the grasper of the carrier illustrated in FIG. 14, grasping a wicket with the bags omitted for clarity.

DETAILED DESCRIPTION OF THE INVENTION

[0060] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.

[0061] FIGS. 1, 1a and 2 illustrate a carrier 20 which may be used within the scope of the present invention. Specifically, the carrier 20 includes a carrier body 22 which is suitably supported for controlled motion as described herein, for example, by a 6-axis robot 26 shown schematically in FIG. 1.

[0062] The carrier body 22 is generally longitudinal along an axial direction 30 with a bag stack bottom end grasping mechanism 34 at one end, and with an upper end 40 for selectively securing to the upper end of the bag stack 42 (see FIGS. 4-11 as described in more detail hereafter). As will be appreciated once a full understanding of the present invention is had, however, the shape of the carrier body 22 is not important to the invention, and the references to it being longitudinal in an axial direction 30 are made herein merely to give a reference to the relative orientation of the of the components thereon (e.g., bottom end grasping mechanism 34 vs. components described hereafter on the upper end 40). As such, the carrier body 22 could be of virtually any shape suitable to support the components so as to be longitudinally spaced in the referenced axial direction 30.

[0063] FIG. 3 illustrates a bag stack 42 such as may typically be found at the end of a manufacturing process. The bag stack 42 includes a plurality of bags 44 (e.g., 250 to 500 bags 44) having aligned holes through which the spaced legs 46 of a wicket 48 extend. A cross-member 50 extends between the legs 46 so that the wicket 48 is generally in a U-shape. The legs 46 are longer than the bag stack 42 is thick, so that the legs 46 may extend a distance beyond the front bag 44 of the stack and the cross-member 50 may be spaced from the rear bag 44 of the stack. Back and front boards 52, 54, which may be optionally provided to assist in securing the bags 44 to the wicket 48, are shown in the FIG. 3 structure. Suitable retainers 56 such as rubber grommets are secured over the front end of the legs 44 to further assist in ensuring that the bags 44 are retained on the wicket 48.

[0064] The bottom end grasping mechanism 34 illustrated in FIGS. 1-2 is adjustably supported on the carrier body by a set of legs 60 which may be suitably adjusted in the axial direction (e.g., by suitable pneumatic or hydraulic pistons in the carrier body 22, or by electric drives, none of which are specifically shown in the Figs.). A first grasping member 62 is secured to the lower ends of the legs 60 and faces forward, and a second grasping member 64 is adjustably mounted to the lower ends of the legs 60 so that it may be selectively moved toward the first grasping member 62 to grasp the lower end of a bag stack 42 therebetween. Specifically, a suitable drive 66 between the grasping members 62, 64, such as a cylinder is provided to selectively move the ends of the second grasping member 64 to the left in the FIG. 1 orientation. Further, a suitable pivot 68 may be provided to allow the second grasping member 64 to be pivoted down clear of the first grasping member 62 as described hereafter. As illustrated in FIG. 2, the second grasping member 64 may include spaced apart fingers 69 for a purpose to be described below. Still further, a suitable cam and slot connection of the second grasping member 64 may be provided whereby the drive 66 will move the fingers 69 through a selected axial and pivoting motion both for grasping (axial motion) and to provide clearance beyond the bottom of the bag stack 42 (pivoting motion) both when grasping and releasing the plurality of bags 44 as will be apparent once a full understanding of the invention described herein is obtained.

[0065] The carrier body upper end 40 includes a wicket leg supporting mechanism 70, with two suitable supporting mechanisms 70 spaced apart suitably to be able to receive both legs 46 of a wicket 48 when the carrier 20 is moved so as to receive the legs 46 in a radial direction therein relative to the axial direction 30. As illustrated, each of the supporting mechanisms 70 include two spaced clamps or grippers 72, with at least one of the grippers 72 of each mechanism 70 suitably supported so as to be selectively movable (e.g., pneumatically, hydraulically, and/or electrically) toward the other gripper so as to selectively grasp a wicket leg 46 therebetween. The grippers 72 may be any suitable construction for supporting the wicket legs 46 such as described herein, with parallel V-shaped grippers being particularly well suited to accommodate different leg sizes (diameters).

[0066] The carrier body upper end 40 also includes a grasper or pick up device 76 which extends radially outwardly from the carrier body 22. In the illustrated embodiment of FIGS. 4-11, the grasper 76 includes a transverse recess 78 whereby the grasper 76 is in the form of an elongated hook. The recess 78 may be a semi-cylindrical recess shaped to mate with a cylindrical wicket cross-member 50, for a purpose to be described hereafter.

[0067] The grasper 76 may, like the supporting mechanism grippers 72, also be suitably supported on the carrier body 22 so that it may be selectively moved in the axial direction 30, though for grasping the wicket 48 in a different manner, as described hereafter. Alternatively, it has been found that the grasper 76 may also suitably operate without any axial movement as discussed hereafter.

[0068] FIGS. 4-11 illustrate the sequence of operation of the present invention, including the carrier 20 described above.

[0069] Initially, a bag stack 42 which has been manufactured, assembled with a plurality of bags 44 on a wicket 48, and inspected is supported on a conveyor or guide rail 80 is therefore ready to be boxed for transport to a user/purchaser. As shown, the wicket 48 is supported with its legs 46 tilted upwardly so that the bags 44 are tilted at their upper end, below which they tend to hang straight down. This orientation is advantageous at the end of the inspection processes in that gravity maintains the bags 44 on the legs 46, allowing the front board 54 and retainers 56 to be added at the end of such handling. However, it should be understood that a different initial orientation could well be used within the scope of the present invention. It should also be understood that the details of the guide rail 80 are not important to the present invention, inasmuch as the present invention relates to the conveyance of bag stacks, wherever supported, to a container.

[0070] The carrier 20 is suitably moved (e.g., by a six-axis robot 26 such as schematically shown in FIG. 1 but not shown in FIGS. 4-12) into position as shown in FIG. 4 where the spaced grippers 72 of the supporting mechanisms 70 are suitably brought together to grasp the ends of the wicket legs 46 therebetween.

[0071] The carrier 20 is then moved away from the guide rail 80 to remove the bag stack 42 therefrom and carry it to an intermediate supporting table 84 (see FIG. 5).

[0072] As illustrated in FIG. 5, the supporting table 84 may be pivoted upwardly to present a supporting surface 86 which is angled relative to vertical such as is further described below. It should be understood, however, that the pivoting of the supporting table 84 may be used to prevent interference between the bag stack 42 hanging from the guide rail 80 and the supporting surface 86 when the table 84 is positioned directly beneath the guide rail 80 such as shown in FIGS. 4-12. However, it should be appreciated that the table 84 may also be positioned elsewhere, clear of the bag stacks 42 hanging on the guide rail 80, in which case it need not be pivoted between transporting of each bag stack 42.

[0073] As the bag stack 42 is moved to the table 84, the lower end of the bag stack 42 may be advantageously swept up over the table 84 to smooth out the bags 44, and also to generally align the lower ends of the bags 44. At this point, the bottom end grasping mechanism 34 may be engaged, whereby the second grasping member 64 is moved toward the first grasping member 62 by the drive 66 in order to grasp the bottom ends of the bags 44 therebetween (see FIG. 6). The lower end 88 of the table 84 may advantageously include slots through which the fingers 69 of the second grasping member 64 may pass to grasp the bags 44 supported on the table 84. This process not only grasps the bags 44 as desired but also causes air to be squeezed from the bags 44 to provide an advantageously compact stack of bags 44. Further, while the bottom end grasping mechanism 34 may readily grasp the bottom ends of bags 44 having gussets providing for expansion or reinforcement of the bags 44, it should be understood that the present invention may also be advantageously used with bags 44 which do not have gussets. It should further be understood that references herein to the bottom end grasping mechanism 34 and to grasping the bottom ends of the bags 44 are not limited to grasping the absolute bottom ends of the bags 44, but are intended to incorporate, for example, grasp the bags 44 adjacent to but above the gussets (e.g., from the sides of the bags 44) or in still higher locations beneath the wicket supported ends of the bags 44. In fact, until the below described step of placing the bag stack 42 in a container, the invention may be advantageously used without grasping the bottom ends of the bags 44 at all.

[0074] The carrier 20 is then moved to carry the bag stack 42, which is supported on both ends by the grasping mechanism 34 and supporting mechanism, 70 so that the cross-member 50 of the wicket 48 is supported by a support 90 on the table 84 (see FIG. 7), at which point the supporting mechanism 70 releases and is moved clear of the wicket legs 46 (see FIG. 8). While the illustrated support 90 consists of a pair of spaced members having upwardly open V-notches therein, many different configurations could also be suitably used within the scope of the invention, including spaced members capable of supporting the wicket cross-member 50 for pivotal movement along its longitudinal axis.

[0075] Movement of the wicket 48 onto the support 90 may also be used to push the wicket 48 through the bags 44 to provide a desired spacing between the back of the plurality of bags 44 and the wicket cross-member 50. That is, a stop for the bags 44 may be provided (e.g., the top of the table supporting surface 86) which prevents the bags 44 from moving beyond a given position, whereby further pushing of the supported wicket legs 46 will move the legs 46 through the openings at the top of the bags 44.

[0076] Thereafter, releasing of the wicket legs 46 will result in the wicket 48 being only pivotally supported at the cross-member 50, and the weight of the bags 44 will tend to pull down on the legs 46 whereby the wicket 48 will pivot to a position in which the wicket legs 46 are not substantially perpendicular to the stack of supported bags 44. The movement of the carrier 20 may also, if desired, be used to facilitate such pivoting by pulling on the bottom end of the bag stack 42 (through the connection at the bottom end grasping mechanism 34).

[0077] Advantageously, the table orientation may allow the weight of the bags 44 to pull down on the wicket legs 46 to provide the desired orientation of the wicket 48 while at the same time supporting enough of the bag weight through its engagement with the table supporting surface 86 so as to ensure that the unsupported weight bearing against the retainers 56 is not sufficient to push the retainers 56 off the wicket legs 46. Of course, where a front board 54 is also used, it too may serve a retaining function in this orientation, and such retaining force could therefore also be taken into account when determining the acceptable weight which can be supported without causing the bags 44 to push themselves off the wicket legs 46. The same is true of static friction forces between the bag holes and the wicket legs 46.

[0078] Therefore, it has been found in some applications that the illustrated 40 to 50 degree (e.g., 45 degree) slope from vertical allows the weight of the bags 44 to pull down on the wicket legs 46 to provide the desired orientation of the wicket 48 while at the same time supporting enough of the bag weight through its engagement with the table supporting surface 86 so as to ensure that the unsupported weight bearing against the retainers 56 is not sufficient to push the retainers 56 off the wicket legs 46. However, still other sloped orientations of the table supporting surface 86 could be used within the scope of the invention, where advantageously the retainer 56 requires a force of X to remove it from the wicket legs 46, with the table supporting surface 86 at an angle which supports Y weight bags 44, where the bags 44 on the bag stack 42 weigh less than X+Y. Consistent with this, it should be appreciated that if the retaining force of the retainer 56 (including related friction forces) is strong enough relative to the weight of the supported bags 44 (i.e., X is greater than the weight of the bags), the table supporting surface 88 may be oriented vertically without any weight support, or no table whatsoever may be provided within the scope of the invention (though if no table is provided, some support for the lower ends of the bags 44 may be advantageously provided to enable those bag ends to be gathered together to facilitate grasping by the bottom end grasping mechanism 34).

[0079] Moreover, in this position the cross-member 50 of the wicket 48 will be supported beyond the end of the bags 44 so that the carrier 20 may be moved back toward the bag stack 42 with the grasper 76 positioned between the upper end 92 of the bags 44 and the wicket cross member 50 (see FIGS. 9 and 9a). Specifically, the grasper 76 as illustrated in FIG. 9a has been moved between the bag upper ends 92 and the wicket cross-member 50 (e.g., by movement of the carrier 20 by the robot 26) and then moved upward (i.e., generally in the axial direction 30) to engage the cross-member 50 in the grasper recess 78.

[0080] At this point, maintaining a sufficient distance between the supported portions on opposite ends of the bag stack 42 allows the entire stack 42 to be carried and moved with the carrier 20. Thus, as shown in FIG. 10, the carrier 20 may be pivoted and moved up clear of the support table 84, with the bag stack 42 supported in a generally horizontal orientation. The carrier 20 may then be moved by the robot 26 to carry the bag stack 42 to a container 96 (e.g., a storage carton or shipping box) and moved down to position the bag stack 42 in the container 96.

[0081] A suitable sensor 98 may be provided to detect when the bag stack 42 is ready to be released (i.e., it is positioned at the bottom of the container 96, whether the bottom surface of the container 96 for the first bag stack 42 put in the container 96 or the top surface of the last bag stack 42 placed in the container 96). For example, an air cylinder can be provided oriented in the radial direction of the bag stack 42 from the carrier 20, with compression of the air cylinder serving to sense (via, e.g., a reed switch sensing displacement of the air cylinder) that the supported bag stack 42 is positioned against the bottom of the open space in the container 96. To adapt for possible lag in sensing and/or stopping the robot 26, the carrier 20 may be retracted up to a slightly higher position before proceeding after the bottom is suitably sensed.

[0082] Feedback from the sensor 98 may also be used to detect faulty boxing. For example, a controller may be used which keeps track of the position in which the last bag stack 42 was placed in a container 96, and then determine from the position at which the sensor 98 indicates that the next bag stack 42 should be released whether some problem occurred with the previous bag stack 42 (e.g., if the spacing is too great, that may indicate that the lower bag stacks 42 are not properly laying flat, and a spacing of too little could similarly indicate some problem in placement of the previous bag stacks 42 in the container 96).

[0083] It should be appreciated that every bag stack 42 placed in the container 96 as described above will necessarily have its wicket 48 oriented with its legs 46 pointing toward the other end of the bags 44 as is most advantageous to ensure compact storage as previously described.

[0084] When properly positioned in the container 96 as described above, the carrier 20 may then be advantageously operated to release the bag stack 42. That is, the grasper 76 may be moved slightly away from the wicket cross-member 50 (whether by pivoting of the carrier 20 or axial movement of the grasper 76) to disengage the cross-member 50 from the recess 78 in the grasper 76, and thereby release the top end of the bag stack 42 (the left end as horizontally oriented and shown in FIG. 11) from the carrier 20.

[0085] Alternatively, as previously noted, releasing the grasper 76 may be caused to occur automatically without any specific axial movement of the grasper 76. That is, it should be appreciated that the wicket cross-member 50 is in significant part maintained in the grasper recess 78 by the sag between the supported ends of the bags 44 pulling the cross-member 50 laterally into the recess 78. Therefore, when the bag stack 42 is placed in the container 96, the bags 44 will stop sagging in the middle as they are supported on their bottom by the bottom of the container 96 or previously loaded bag stacks 42. As a result, the force tending to hold the cross-member 50 in the recess 78 will be eliminated.

[0086] With the bag stack 42 in the container 96, the bottom end grasping mechanism 34 is also disengaged (from the bottom ends of the bags 44), for example by moving the second grasping member 64 away from the first grasping member 62 to release the bags 44. The second grasping member 64 may also be pivoted as previously described to assist in clearing its fingers 69 from the bags 44. The carrier 20 may then be retracted up out of the container 96, leaving the bag stack 42 properly positioned therein such as illustrated in FIG. 11.

[0087] Prior to leaving the container 96, the carrier 20 or other suitable component may also be swept over the bag stack 42 from top to bottom (i.e., left to right in the Figures), if desired, to ensure proper orientation of the wicket legs 46 and to also ensure that the bottom of the bags 44 have not folded over while retracting the bottom end grasping mechanism 34 from the container 96.

[0088] Additional bag stacks 42 may be placed in the container 96 until the container 96 is deemed full, as may be determined in any suitable manner, including a counter determining that the desired number of bag stacks 42 have been placed in that container 96. It should be understood that such additional bag stacks 42 may be alternated when placed in the container 96, so that the bottom end of each stack 42 is positioned on top of the top end of the bag stack 42 therebeneath. This may most advantageously permit compact boxing of bag stacks 42 having bags 44 with gussets on their bottom end, as such gussets will cause the bottom end to be thicker than the top end.

[0089] FIGS. 12-16 disclose an alternate embodiment for supporting bag stacks 42 in order to advantageously place the bag stacks 42 in a desired container. The bag stacks 42 may be substantially identical to the bag stacks 42 as previously described. Components such as grasper 76′ which are comparable to components in the first described embodiment (in FIGS. 1-11) have been given similar reference numerals in FIGS. 12-16 but with “prime” (′) added.

[0090] More specifically, FIGS. 12-16 disclose an alternative embodiment of the grasper 76′ used to secure to the wicket cross-member 50 so as to advantageously ensure that the that the wicket 48 will be properly oriented for compact piling of bag stacks 42 when placed in a container 98 such as already described herein.

[0091] As illustrated particularly in FIGS. 12-13, a suitable wagon 110 may be provided to secure a wicket 48 on which a plurality of bags 44 will be hung, which wagon 110 may be used to carry the wicket 48 on the conveyor during manufacture, assembly and inspection such as previously described. The wagon 110 includes a central recessed portion 112 with slots 114, 116 on opposite sides in which a wicket 48 can be supported with the cross-member 50 spaced from the back of the recessed portion 112 and with the wicket legs 46 supported to extend generally forwardly to receive a plurality of bags 44 thereon. The front of the wagon 110 will also secure the bags 44 forwardly of the cross-member 50 so that the center portion of the cross-member 50 is clear of blockages therearound.

[0092] Once an understanding of this embodiment is had, it should be appreciated that the illustrated wagon 110 is, however, merely one example of a suitable wicker support, and that any structure which supports the wicket 48 of a bag stack 42 which is ready for boxing so that the wicket legs 46 do not pivot down and so that access may be had around the cross-member 50 to grasp the cross-member 50 would be suitable.

[0093] FIGS. 14-16 illustrate a carrier 20′ including a grasper 76′ on its upper end. While not illustrated in FIGS. 14-16, a suitable bottom end grasping mechanism 34 is also provided with the carrier 20′ of this second embodiment. The bottom end grasping mechanism 34 may function as already described to grasp the bottom end of the plurality of bags 44 in conjunction with the grasping of the wicket 48 by the grasper 76′. This second embodiment uses a differently operating grasper 76′ at the upper end of the carrier 20′, which grasper 76′ functions so that the carrier need not first support the wicket 48 by its legs 46 as described with the first described embodiment, and therefore the below description of this second embodiment focuses on the gripper 76′ on the upper end of the carrier.

[0094] The carrier 20′ is suitably supported for movement such as previously described, as by a robot. In this embodiment, the grasper 76′ may consist of a set of grasping arms 120, 122 with oppositely facing longitudinal recesses 126, 128 adapted to engage opposite sides of the wicket cross-member 50. Specifically, in accordance with this embodiment, the carrier 20′ is suitably moved, as by a robot, so as to position the grasper arms 120 between the wagon 110 and the wicket cross-member 50 and the other grasper arm 122 between the wicket cross-member 50 and the supported bags 44. It should be appreciated that the recessed portion 112 of the wagon 110 functions to support the wicket 48 so that space is provided on both sides of the wicket cross-member 50 to enable the grasper arms 120, 122 to be so positioned.

[0095] As illustrated in FIGS. 14-16, the grasper 76′ includes a central grasper arm 122 with two laterally spaced grasper arms 120, with the recesses 126, 128 in each being V-notches. It will be appreciated that such a configuration will allow the grasper 76′ to grasp wicket cross-members 50 having a variety of diameters by moving the arms 120 toward arm 122 in the direction of arrow 130 once the arms 120, 122 have been positioned on opposite sides of the wicket cross-member 50 with their recesses 126, 128 aligned with the cross-member 50 as illustrated in FIG. 14. However, it should be understood that the illustrated grasper 76′ is merely one suitable grasper 76′ which may be used with the presently described embodiment, and that any grasper which will pick up the bag stack 42 by grasping the cross-member 50 would be suitable.

[0096] After grasping the cross-member 50, the grasper 76′ is suitably moved (e.g., by a robot) in the direction of arrow 134, which direction is substantially parallel to the orientation of the slots 114, 116 in the wagon 110. Once the wicket 48 has been moved out of the slots 114, 116 so that the wagon 110 no longer engages the wicket legs 46, the weight of the wicket 48 and the supported bags 44 will cause the wicket 48 to pivot down about the cross-member 50 in the direction of arrow 138 as illustrated in FIG. 15.

[0097] Stops 144 may be adjustably supported beneath the wagon 110, such as by a suitable cylinder and piston 150, 152 which permit the stops 144 to be either aligned beneath the wicket legs 46 (as in FIG. 15) or retracted away (in the direction of arrows 158) clear of the wicket legs 46 (as in FIG. 16).

[0098] When the grasper 76′ has grasped a wicket cross-member 50 and is moving it out of the wagon slots 114, 116 as illustrated in FIG. 15, the stops 144 are extended so as to be aligned with each of the wicket legs 46. As a result, when the wicket legs 46 clear the wagon slots 114, 116 and fall down under their own weight and the weight of the supported bags 44, the wicket legs 46 will be stopped by the stops 144 such as illustrated in FIG. 15. The stops will thus prevent back and forth free swinging of the wicket 48 and will also block the supported bags 44 from sliding off of the ends of the wicket legs 46. That is, while the retainers 56 on the wicket legs 46 (together with, e.g., the static friction forces between the bags 44 and the wicket legs 46) should be sufficient to retain the bags 44 on the wicket legs 46 thereafter, the forces existing when the wicket 48 is initially swinging down (e.g., the momentum down of the bags 44 as well as the lesser dynamic friction forces between the bags 44 and the legs 46) may result in a situation in which the bags 44 could force the retainers 56 off the legs, in which case at least some of the bags 44 would also fall of the legs 46. The stops 144 block the retainer 56 and bags 44 to prevent that from occurring. Once that initial swing down of the wicket 48 is stopped, the stops 144 may be retracted.

[0099] As illustrated, the stops 144 temporarily will block the legs 46 in an initial non-vertical orientation. However, it should be appreciated that stops could also be positioned to prevent falling off of the retainer 56 and bags 44 even if pivoting of the legs 46 through vertical were permitted. It should also be appreciated that if the retainers 56 are secured on the wicket legs 46 sufficiently to support the bags 44 even under a free-fall pivoting condition of the wicket 48 when pulled off the wagon 110, then the stops 144 could be omitted.

[0100] As previously mentioned, in addition to the grasper 76′ grasping the wicket cross-member 50 as described above, a suitable bottom end grasping mechanism also grasps the bottom ends of the bags 44. As a result, the bag stack 42 is supported on opposite ends by a carrier 20′ positioned on one side of the bags 44, with the top end supported by the wicket wire cross-member 50 which is positioned on the opposite side of the bags 44 from the carrier 20′. The carrier 20′ may therefore be moved (as by a robot) to ultimately advantageously place the bag stack 42 in a container with the wicket 48 properly oriented as already described with the first embodiment.

[0101] It should therefore be appreciated now that the present invention will allow for reliable, compact and easy piling of stacks of wicket supported bags in a container in a predetermined pattern. Further, it should be appreciated that this may be accomplished using a mechanism which is substantially oriented on only one side of the bag stack as is necessary to permit the mechanism to be removed from the container after placing a bag stack therein.

[0102] Still other aspects, objects, and advantages of the present invention can be obtained from a study of the specification, the drawings, and the appended claims. It should be understood, however, that the present invention could be used in alternate forms where less than all of the objects and advantages of the present invention and preferred embodiment as described above would be obtained.

Claims

1. A method of boxing a bag stack having a first thickness and comprising a plurality of bags each having a pair of holes at one end receiving legs of a U-shaped wicket, said member legs being connected at one end by a cross-member on one side of said bag stack with the other ends of said legs projecting from the other side of said bag stack, comprising the steps of:

(a) supporting said bag stack by grasping both said cross-member and said bag stack other end from said other side of said bag stack;

(b) moving said supported bag stack into a container; and

(c) releasing said bag stack in said container.

2. The method of claim 1, wherein said step of supporting said bag stack by grasping said cross-member from said other side of said bag stack comprises extending a grasper from said other side of said bag stack to grasp said cross-member.

3. The method of claim 1, further comprising, prior to step (a), the steps of:

supporting said wicket on a support whereby said wicket legs tilt upwardly and at least a portion of said wicket cross-member is clear of blockages therearound;

grasping said cross-member portion of said wicket supported on said support; and

removing said wicket from said support.

4. The method of claim 3, wherein said wicket may pivot down about said wicket cross-member when removed from said support, and further comprising the step of blocking said wicket legs to retain said plurality of bags on said legs after downward pivoting of said wicket resulting from said removing step.

5. The method of claim 4, wherein said blocking step comprises locating stops beneath said wicker legs during said removing step.

6. The method of claim 5, wherein said locating step locates said stops to be engaged by said wicket legs to temporarily support said legs in a non-vertical position after said removing step.

7. The method of claim 1, wherein said step of moving said supported bag stack into said container comprises moving said bag stack whereby said bag stack one side faces the bottom of the container.

8. The method of claim 1, wherein said step of supporting said bag stack by grasping said cross-member from said other side of said bag stack comprises:

supporting said bag stack by supporting said leg other ends of said wicket;

carrying said leg other ends of said U-shaped member to a support;

releasing said leg other ends to support said cross-member of said wicket on said support with said cross-member spaced from said plurality of bags; and

extending a grasper from said other side of said bag stack and engaging said grasper with a side of said cross-member facing said plurality of bags.

9. The method of claim 8, wherein said cross-member of said wicket is spaced from said bags on said wicket legs whereby the weight of said bag stack causes said wicket legs to be oriented downwardly after said step of releasing said leg other ends.

10. The method of claim 8, wherein said grasping said cross-member during said step of supporting said bag stack comprises engaging said cross-member with a grasper on a side facing said other end of said bag stack.

11. The method of claim 8, wherein said step of supporting said bag stack generally directs said other ends of said wicket legs toward said bag stack other end.

12. The method of claim 8, further comprising supporting said plurality of bags in a non-vertical orientation when performing said step of releasing said other leg ends.

13. A method of boxing a bag stack having a first thickness and comprising a plurality of bags each having a pair of holes at one end receiving legs of a U-shaped member, said member legs being connected at one end by a cross-member and having a length greater than said first thickness with a retainer on the other ends of said legs adapted to maintain said bags on said legs, comprising the steps of:

supporting said bag stack by supporting said leg other ends of said U-shaped member;

carrying said leg other ends of said U-shaped member to a support;

releasing said leg other ends to support said cross-member of said U-shaped member on said support;

supporting said bag stack by grasping said bag stack other end and grasping said cross-member;

moving said supported bag stack into a container; and

releasing said bag stack in said container.

14. The method of claim 13, wherein said step of releasing said leg other ends causes said cross-member of said U-shaped member to be positioned beyond said one ends of said plurality of bags.

15. The method of claim 14, wherein said step of releasing said leg other ends causes said U-shaped member to pivot about the cross-member.

16. The method of claim 14, wherein said step of releasing said leg other ends further comprises pulling said other end of said plurality of bags.

17. The method of claim 13, wherein said cross-member of said U-shaped member is spaced from said bags on said U-shaped member legs whereby the weight of said bag stack causes said U-shaped member legs to be oriented downwardly after said step of releasing said leg other ends.

18. The method of claim 13, wherein said grasping said cross-member during said step of supporting said bag stack comprises engaging said cross-member with a grasper on a side facing said other end of said bag stack.

19. The method of claim 18, wherein said step of releasing said bag stack comprises moving said grasper toward said other end of said bag stack.

20. The method of claim 13, wherein said step of supporting said bag stack generally directs said other ends of said U-shaped member legs toward said bag stack other end.

21. The method of claim 13, wherein said cross-member is on one side of said bag stack and said leg other ends project from the other side of said bag stack, and said supporting said bag stack is performed by grasping said bag stack other end and grasping said cross-member from said other side of said bag stack.

22. The method of claim 13, further comprising supporting said plurality of bags in a non-vertical orientation when performing said step of releasing said other leg ends.

23. The method of claim 22, wherein said step of carrying said leg other ends of said U-shaped member to a support includes sweeping said bag stack upwardly over a surface.

24. The method of claim 22, wherein said step of supporting said bag stack in a non-vertical orientation supports said plurality of bags at an angle of 40 to 50 degrees relative to vertical.

25. The method of claim 13, wherein said retainer comprises grommets on said other ends of said legs.

26. A method of boxing a plurality of bag stacks, said bag stacks having a first thickness and comprising a plurality of bags each having a pair of holes receiving legs of a U-shaped support, said legs being connected by a cross-member and having a length greater than said first thickness, comprising the steps of:

(a) grasping said leg other ends of said U-shaped member of a bag stack;

(b) carrying said leg other ends of said U-shaped member of said first bag stack to a support;

(c) releasing said grasped leg other ends to support said cross-member of said U-shaped member on said support and allow pivoting of said U-shaped member about said supported cross-member;

(d) grasping both said bag stack other end and said cross-member from one side of said bag stack;

(e) moving said grasped bag stack into a container;

(f) sensing when said grasped bag stack may be released;

(g) releasing said bag stack into said container;

(h) repeating steps (a) through (g) with additional bag stacks for said container until it is determined that no more bag stacks should be placed in said container.

27. The method of claim 26, wherein additional bag stacks are released into said container in alternating orientations with one end of a subsequent bag stack adjacent the other end of the underlying bag stack.

28. The method of claim 26, wherein said step of releasing said grasped leg other ends causes said cross-member of said U-shaped member to be positioned beyond said one ends of said plurality of bags.

29. The method of claim 28, wherein said step of releasing said grasped leg other ends causes said U-shaped member to pivot about the cross-member.

30. The method of claim 28, wherein said step of releasing said grasped leg other ends further comprises pulling said other end of said plurality of bags.

31. The method of claim 26, wherein said cross-member of said U-shaped member is spaced from said bags on said U-shaped member legs whereby the weight of said bag stack causes said U-shaped member legs to be oriented downwardly after said step of releasing said leg other ends.

32. The method of claim 26, wherein step (d) includes engaging said cross-member with a grasper on a side facing said other end of said bag stack.

33. The method of claim 32, wherein step (g) includes moving said grasper toward said other end of said bag stack.

34. The method of claim 26, wherein step (c) causes said other ends of said U-shaped member legs to be generally directed toward said bag stack other end.

35. The method of claim 26, wherein said cross-member is on one side of said bag stack and said leg other ends project from the other side of said bag stack, and step (d) is performed by grasping both said bag stack other end and said cross-member from said other side of said bag stack.

36. The method of claim 26, wherein said step of supporting said bag stack supports said plurality of bags in a non-vertical orientation.

37. The method of claim 36, wherein step (b) includes sweeping said bag stack upwardly over a surface.

38. The method of claim 36, wherein said step of supporting said bag stack in a non-vertical orientation supports said plurality of bags at an angle of 40 to 50 degrees relative to vertical.

39. The method of claim 36, wherein a removable retainer retains said plurality of bags on said U-shaped member legs, and said non-vertical orientation of said plurality of bags leaves a gravity pulling force of Z in the direction of said U-shaped member legs, where Z is less than the force required to remove the retainer from said U-shaped member legs.

40. A carrier for a bag stack having a first thickness and comprising a plurality of bags each having a pair of holes at one end receiving legs of a U-shaped member, said U-shaped member legs being connected at one end by a cross-member and having a length greater than said first thickness, said carrier extending along a generally axial direction and adapted to selectively carry said bag stack oriented in said generally axial direction and comprising:

a grasping mechanism on one axial end of said carrier and extending a generally radial direction from said axial direction for selectively grasping said bag stack other end;

a grasper on the other axial end of said carrier and selectively extendable in said generally radial direction, said grasper being selectively engageable with said cross-member of said U-shaped member when in an extended position.

41. The carrier of claim 40, wherein said grasper has a surface facing axially away from said grasping mechanism and adapted to selectively mate with said cross-member of said U-shaped member.

42. The carrier of claim 41, further comprising a drive for selectively moving said grasping mechanism and said grasper axially relative to one another.

43. The carrier of claim 40, further comprising a robot secured to said carrier to selectively move said carrier.

44. The carrier of claim 40, wherein said grasping mechanism is radially movable to grasp a bag stack other end and pivotally movable away from said bag stack other end to release said bag stack other end from said grasping mechanism.

45. The carrier of claim 40, wherein said cross-member is on one side of said plurality of bags, and further comprising stops selectively positionable beneath said U-shaped member legs on the other side of said plurality of bags.

46. A carrier for a bag stack having a first thickness and comprising a plurality of bags each having a pair of holes at one end receiving legs of a U-shaped member, said U-shaped member legs being connected at one end by a cross-member and having a length greater than said first thickness with a removable retainer on the other ends of said legs adapted to maintain said bags on said legs, said carrier extending along a generally axial direction and adapted to selectively carry said bag stack oriented in said generally axial direction and comprising:

a supporting mechanism on one axial end of said carrier and adapted to selectively support said other leg ends of said U-shaped member in a generally radial direction from said axial direction;

a grasping mechanism on the other axial end of said carrier and extending in said generally radial direction for selectively grasping said bag stack other end; and

a grasper having a surface adapted to selectively mate with said cross-member of said U-shaped member, said mating surface facing axially away from said grasping mechanism.

47. The carrier of claim 46, further comprising a robot secured to said carrier to selectively move said carrier.

48. The carrier of claim 46, wherein grasping mechanism is radially movable to grasp a bag stack other end and pivotally movable away from said bag stack other end to release said bag stack other end from said grasping mechanism.

49. The carrier of claim 46, further comprising a support adapted to hang said bag stack from said cross-member of said U-shaped member.

50. The carrier of claim 49, wherein said support supports said cross-member of said U-shaped member for pivoting about its longitudinal axis.

51. The carrier of claim 49, wherein said support is aligned with said plurality of bags.

52. The carrier of claim 49, further comprising a supporting table at an angle to vertical for supporting said bag stack hanging from said support in a non-vertical orientation.

53. The carrier of claim 52, wherein said supporting table defines a plane of a supporting surface, and said support supports said cross-member of said U-shaped member above said plane of said supporting surface.

54. The carrier of claim 52, wherein said supporting table is selectively adjustable to different orientations relative to vertical.

55. The carrier of claim 52, wherein said supporting table is at an angle of 40 to 50 degrees relative to vertical.

56. The carrier of claim 52, wherein:

said removable retainer requires a force of X to remove it from said U-shaped member legs;

said supporting table is at an angle which supports Y weight of said bag stack hanging from said support; and

said plurality of bags weigh less than X+Y.

57. The carrier of claim 52, wherein said grasping mechanism includes a plurality of spaced fingers extending in a generally axial direction and said supporting table includes a plurality of matching slots in its lower end whereby said grasping mechanism fingers are adapted for radial movement between said supporting table slots to grasp a bag stack other end supported on said supporting table.