Bag retrieval assembly and bag for pressed bales

A bag retrieval assembly and bag, which facilitates the covering of a bale of cotton or other fibrous material, are discussed. The bag is configured to be used with the bag retrieval assembly, which is configured to manipulate the bag from a stacked or stored configuration to an open configuration that may be raised and held into a position for further processing.

BACKGROUND

Conventionally, manual labor has been used to cover a bale of cotton or other fibrous material with a bag to protect the bale from damage or contamination during transport, and some instances to comply with trade requirements. To bag a bale using prior art methods, one or, more commonly, two or more workers must extend an open end of a bag over a bale chute in preparation for the bale to be inserted through the bale chute and into the bag, preventing the workers from accomplishing other tasks during this time. Conventional bale bagging devices also contain numerous moving parts, on which workers may catch themselves or clothing, causing serious injuries, death, and/or property damage.

SUMMARY

The present invention provides a bag retrieval assembly and bag, which facilitate the covering of a bale of cotton or other fibrous material. The bag is configured to be used with the bag retrieval assembly, which is configured to manipulate the bag from a stacked or stored configuration to an open configuration that may be raised and held into a position for further processing. The present invention may reduce manual labor requirements, protect the bale from damage or contamination during transport, and in some instances, help to comply with trade requirements.

In one aspect, a bag is provided which includes a body portion having a bottom end, opposed first and second panels extending from the bottom end, and opposed first and second side panels extending from the bottom end and connecting the first and second panels. The bottom end, the first and second panels and the first and second side panels are assembled together to define a receptacle space. The receptacle space has an open end located opposite the bottom end. The bag also includes a cutout portion defined on the first panel. The cutout portion is positioned at a location on the first panel more proximate to the open end than to the bottom end. The bag may also include a mark positioned proximate to the cutout portion, such that the mark provides an indication of the location of the cutout portion, for example, to a visualization system.

Also provided herein is a bag for bagging a pressed bale comprising a body portion having a bottom end, opposed first and second panels each comprising an exterior surface and an interior surface extending from the bottom end, and opposed first and second side panels extending from the bottom end and connecting the first and second panels; the bottom end, the first and second panels and the first and second side panels defining a receptacle space with an open end located opposite the bottom end. A cutout portion is formed through the exterior surface and the interior surface of the first panel, the cutout portion positioned at a location on the first panel nearer the open end than the bottom end; and wherein when the open end is closed, the cutout is covered on the interior surface side by the interior surface of the second panel.

In another aspect, a bagging system is provided including a bag retrieval assembly for retrieving a bag, a bag positioning assembly for opening the bag retrieved by the bag retrieval assembly and preparing the bag to receive a bale, and a bag stuffing assembly for inserting the bale into the bag. The bag retrieval assembly includes a robotic device configured to move along variable paths to variable positions; and an end effector coupled to the robotic device. The end effector includes a beak assembly, and a visualization system configured to detect and isolate features of a digitized image. The beak assembly and the visualization system are each mounted generally in-line along a central axis of end effector.

In yet another aspect, a method for retrieving a bag for use in a bagging system is provided. The method includes detecting a cutout defined on a first side of a bag; moving a beak assembly having a first arm and a second arm into a position proximate to the cutout; inserting at least a tip of the first and second arms into the cutout; and expanding the beak assembly until the distance between the tips of the first and second arms is greater than the diameter of the cutout.

In still yet another embodiment, a method for retrieving a bag for use in a bagging system is disclosed. The method comprising detecting an indicium defined on an exterior surface of a first side of a bag; moving an end effector towards the indicium; deploying an attachment device mounted on the end effector to grab the bag; and wherein the attachment device comprises a vacuum source.

In yet another embodiment, a method for retrieving a bag and placing a pressed bale into the bag is provided. Said method comprising the steps: moving a pressed bale into a bale bagging assembly; inserting a probe into a cut section of a bag, said bag sized for bagging a pressed bale; opening an open end of the bag; moving the bag and the probe relative to one another to separate the bag from the probe; and moving the pressed bale into the bag through the open end of the bag.

Other aspects and variations of the bag and bag retrieval assembly summarized above are also contemplated and are more fully understood when considered with respect to the following disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of a bag and a bag retrieval assembly provided in accordance with aspects of the present invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the features and the steps for constructing and using the bag and bag retrieval of the present invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and structures may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. As denoted elsewhere herein, like element numbers are intended to indicate like or similar elements or features.

To facilitate an understanding of the embodiments of the bag and bag retrieval assembly of the present invention, the general architecture and operation of a preferred bagging assembly is described, which is disclosed in Ser. No. 61/033,376 and previously incorporated herein by reference.FIG. 1is a simplified illustration of a bagging assembly100, which provides a means to efficiently and effectively insert an uncovered pressed and strapped bale of fibrous material into a bag, seal the bag, and transport the sealed bag away from the bagging assembly.

In an exemplary embodiment, bagging assembly100includes a system area102, which houses various bale bagging components generally referred to herein as a housing, having abase104, that may be a floor or a slab or a metal frame or foundation, side walls106, that may be metal, plastic, wood or steel frames or steel beams, and a top wall108, that may be a roof of a building or an upper frame or beam.

Bagging assembly100includes, within housing102, a bag retrieval assembly110for retrieving bags from a stack of bags118, a bag positioning assembly112for opening the bag and preparing the bag over a chute to receive a bale, and a bag stuffing assembly114for stuffing or inserting the strapped bale into the bag. Generally speaking, bagging assembly100operates continuously to retrieve a bag116from a stack of bags118, position bag116to receive a bale120having at least two straps120a,120b, insert bale120into bag116, seal bag116, and push the sealed bag off of the assembly to then bag a next bale. The foregoing description is described in detail in provisional application No. 61/033,376.

FIG. 2Ais a simplified perspective view of bag116for use with bag retrieval assembly110in accordance with an embodiment of the present invention. With continued reference toFIG. 1and now with reference toFIG. 2A, in one embodiment, bag116includes a body having a first panel, side, or layer202and a second panel, side, or layer204, which extend from a bottom end or closed end208. Bag116also includes first side panel209and second side panel211, which also extend from bottom end208and connect first panel202to second panel204. Bottom end208, first and second panels202and204and first an second side panels209and211together define a generally elongated receptacle space213with an open end206located opposite bottom end208. In one embodiment, bag116may be provided with a substantially flat bottom end208, folded gussets formed in the first and second side panels209and211, and one or more horizontal folds or creases215so that bag116may be folded and unfolded, into two or more folds, between the use and storage configurations.

Bag116may be formed by folding and assembling a length of material, using adhesives, heat or pressure welding, sewing or other well known bag assembling techniques. The length of material may include, but is not limited to plastic, burlap, cotton, nylon, polypropylene, polyethylene, polyester, paper, or similar bag making materials. Bag116may be adapted so that the body of the bag is convertible between an expanded use configuration (FIG. 2A), which shows the first and second side panels209and211partially expanded, and a collapsed storage (folded) configuration (stack118,FIG. 1), which shows wherein the first and second side panels209,211each folded when the open end is closed.

A hole or cutout210is formed on and extends through first panel202of bag116. It should be understood that the position of cutout210on first panel202is governed, at least in part, by movement and operation of the bag retrieval assembly110for “picking-up” bag116, as described in detail below. Generally, however, cutout210may be positioned on first panel202in relative proximity to open end206of bag116. In one embodiment, cutout210is positioned closer to open end206than to bottom end208. Most preferably, the cutout210is located on only one of two panels, such as the first panel202and not also the second panel204. Also, when the bag is in a closed configuration and laid flat, the cutout210is superimposed against a solid surface layer of the second panel204. Although other cutouts may be incorporated elsewhere on bag116, the main cutout210on the first panel should not have a corresponding cutout located on the second panel. This allows a pickup to grab the bag116by only one of its side panels, as further discussed below. In a broadest aspect of the present invention, an indicium is provided on an exterior surface of the first panel202for use by a detection system to move towards the bag to then enable a retrieving device to grab the bag. The indicium can be a cutout, several cutouts, a mark, a combination mark and cutout, a logo, a hook, a notch, a metal insert, a sensor, a radio frequency identification (RFID) member, combinations thereof and similar devices to enable detection by a detection system. In one example, a support grommet is added to a bag having a cutout to facilitate pickup by allowing additional detection mechanism to key in on the grommet. The grommet can also add strength or texture to a less sturdy bag. As used herein, a cutout or a slit can be used interchangeable. More generically, a “cut section” may include a cutout or a slit or other cut features, such as a stamped section, a ripped section, a punched section, etc.

In one embodiment, an indicator or mark may be placed on bag116to help locate or pinpoint the cutout210so that it is more “visible,” especially to a camera system. OCR system, machine vision system or similar visualization systems, which uses the cutout and/or the indicator to locate a grabbing mechanism relative to the cutout to pick up the bag. For example, in one embodiment, cutout210may be encircled with a contrasting color band or other contrasting feature212a, such as reflective coating or paint. In other embodiments, cutout210may be formed of varying geometrical shapes, features or combinations thereof. For example, with no intent to be limiting but only exemplary.FIGS. 2B(a)-(c) illustrate cutout210as a polygon, an ellipse, and a star. In yet another alternative embodiment, a specific mark212b, such as a word or a logo may be positioned proximate to cutout210, or may incorporate all or a part of cutout210into the mark212b, to indicate the location of cutout210. A mark212cmay be placed on first panel202, such that when mark212cis detected by the visualization system, the location of cutout210may be determined relative thereto. However, other schemes and devices or sensors for detecting edges, visual contrasts, marks, etc. may readily be used without deviating from the spirit and scope of the present embodiment.

Bag116is stacked on stack of bags118, such that first panel202and cutout210are exposed at the top of stack118to be accessed by bag retrieval assembly110(FIG. 1). In some embodiments, bag116and other bags in the stack of bags118may be folded when stacked and aligned in uniform fashion, e.g., with the open end of each bag oriented in the some direction. Alternatively, the first panel202and cutout210may alternate along two different ends of the stack of bags so that the bag retrieval assembly110has to traverse back and forth to pick up the next succeeding top bag on the stack of bags. Other possibilities include random stacking so that the indicia of each bag varies, stacking the bags in organized manner but in multiple stacks, stacking the bags in smaller folds, similar to stacked shirts found at department stores, etc. Where appropriate, nesting between two adjacent stacks as shown inFIGS. 3A and 3B, or grid stacking as shown inFIGS. 3C and 3Dmay be used. Still in other embodiments, the plurality of bags are provided in a roll format and mounted on a, tube, spindle or shaft for individually removing a bag from the roll of bags. In yet another embodiment, the stack of bags may be stacked in any order and fashion provided the cutout or210is exposed a sufficient amount to be accessed by a pickup probe.

FIG. 3is a perspective view of bag retrieval assembly110configured for use to “pick-up” a bag116from a stack of bags located on a support119, such as a palette, and lift the bag into place for further processing by the bagging assembly (FIG. 1) in accordance with an embodiment of the present invention. With continued reference toFIGS. 1 and 2Aand also now with reference toFIG. 3, bag retrieval assembly110includes a robotic device300, including an end effector302, disposed at the end of a robotic arm304, and adapted to locate and pickup bag116as described below. With reference toFIG. 1, the robotic device300is understood to be located in the vicinity of the stack of bags118. As further discussed below, the robotic device300may move along multiple axes, just one axis, or is stationary when retrieving the bag. Alternatively or in addition to movement by the robotic device300, the pallet or stack of bags118may be configured to move in the X, Y, and/or Z directions to effect the same results, such as moving to the fixed robotic device to then permit the end effector to pick up the bag.

End effector302may be manipulated with robotic arm304using well-known robotic motion techniques controlled by a computer, vector drives, servo drives, electro mechanical sensors and/or other common control devices known in the art. These controllers may be closely placed, producing a master control center, or each device may have its own controller, wherein signals coordinate functions between systems. Alternatively, a Cartesian coordinate robot may be used to move the end effector to perform the bag pickup function, as further discussed below.

In one embodiment, with reference toFIG. 4, end effector302includes a beak assembly306, at least one nozzle308formed at a tip of beak assembly306, a conduit318(shown in phantom) and visualization system310, each mounted generally in-line along a central axis312of end effector302. An exemplary visualization system310is a DVT Smartimage System, which is a division of Cognex Corporation of Natick, Mass. It should be understood that some components necessary to support the mechanical or electrical operations of beak assembly306, such as various linear drive mechanisms, gears, servos, motors and the like and visualization system308, such as electronic support equipment, may also be co-located on end effector302, although they are not shown inFIG. 3for clarity.

As shown inFIG. 4, beak assembly306and visualization system310are positioned to operate at opposite ends420and422of the end effector, and in opposite directions relative to each other. The “working end” of end effector302is considered end420or end422that is “facing” or directed at the target to be retrieved, for example, bag116. Depending on the operation, either end420or end422will face the target. To place beak assembly306and visualization system310at the working end of end effector302, the end effector may be rotated at least 180 degrees as indicated by arrow424, or along some other a pivot point or axis located on the end effector.

A bag attachment mechanism314may also be coupled to end effector302and used to secure bag116to end effector302. In one exemplary embodiment, bag attachment mechanism314may include a vacuum device capable of generating an effective amount of vacuum so that as end effector302is raised, bag116is held by a vacuum force and rises with the end effector. For example, bag attachment mechanism314may include a plurality of vacuum cups316used to ensure that bag116is secured to end effector302. Alternatively, a perforated vacuum plate, or any other device suitable to enable end effector302to “grab” bag116to be removably attached to end effector302may also be used as an alternative to, or in addition to, vacuum device314. In one embodiment, a sensor (not shown) may be incorporated into end effector302so that as it contacts bag116, a signal is sent to a controller to activate vacuum device314.

Referring now toFIGS. 3 and 4, in one embodiment, end effector302may be lowered such that visualization system310at the working end of end effector302is made to face first panel202of bag116. Visualization system310may include for example a camera, an OCR device, a machine vision device or the equivalent, capable of detecting and isolating desired portions, shapes, or features of a digitized image or video stream of first panel202. In one embodiment, robotic arm304is configured to position end effector302, with visualization system310facing first panel202of bag116, along variable paths to variable positions relative to cutout210, such that visualization system310may detect and isolate desired portions or features of cutout210and mark212. For example, in one embodiment, visualization system310detects a contrasting color band212encircling cutout210. A signal is sent to the robotic controllers and in response, the robotic controllers cause robotic arm304to move end effector302into a desired position relative to cutout210. For example, end effector302is moved to align its central axis312with the geometric center of cutout210. Once in position, the position of end effector302in the x, y plane is fixed or locked.

Alternatively, visualization system310may be used to detect other features of bag116, other than cutout210. For example, visualization system310may detect a logo or word, a geometric feature, a plurality of geometric features, a tag and the like, located away from cutout210. Detection of one of these alternative features may cause a signal to be sent to the robotic controllers, which in turn, causes the controllers to manipulate end effector302into a desired position relative to cutout210. Generally, the desired position is where central axis312of end effector302and visualization system310are substantially in direct alignment with the geometric center of cutout210.

With reference now toFIG. 5A, once in its fixed position above cutout210, end effector302is made to rotate180degrees (arrow424,FIG. 4), to cause beak assembly306and nozzle308to rotate toward bag116, which then becomes the working end. After this rotation of end effector302, beak assembly306and nozzle308are now directed at first panel202of bag116. In this position, central axis312of beak assembly306is substantially in direct alignment with the geometric center of cutout210.

As shown inFIG. 5B, once beak assembly306is positioned above cutout210, end effector302may be lowered along the z-axis to grip the bag. End effector302is lowered until at least a portion of beak assembly306protrudes through cutout210. Generally, the portion of beak assembly306that enters cutout210protrudes through cutout210to a depth necessary to ensure that nozzle308passes through cutout210and into the interior of bag116. The end of beak assembly306is usually moved until it contacts second panel204of bag116and uses the contact on the second panel as a leverage to open the open end of the bag, as further discussed below.

FIG. 6Ais a simplified view of open end206of bag116after at least a portion of beak assembly306enters into cutout210. As show inFIG. 6A, nozzle308, positioned at the end or tip of beak assembly306, enters into the interior of bag116. In one embodiment, a gas, such as air, is introduced into an inner cavity (not shown) of beak assembly306through, for example, conduit318(FIG. 4) until the air reaches nozzle308.

As shown inFIG. 6B, gas A exits nozzle308to cause bag116to open or inflate. The inflation causes the otherwise touching interior surfaces205aand205b(FIG. 2) of first and second panels202and204to separate causing bag116to open. In addition, the inflation causes first panel202to rise relative to end effector302until an exterior surface207aof first panel202contacts vacuum device314, in this embodiment, vacuum cups316. In one embodiment, vacuum is supplied to the cups316at the same time air is forced through the exit nozzle308so that as the first panel202flails from the purged air and touches the vacuum cups, it is grabbed by the cups. Alternatively, vacuum may be sequenced to open slightly before or slightly after the air flow to produce vacuum at the cups. Vacuum pressure may be supplied using a compressor, educator pump, generator, or any other well known vacuum producing apparatus or method. Accordingly, exterior surface207aof first panel202of bag116adheres to vacuum cups316and is thus removably secured to end effector302.

FIG. 7Ashows a cutaway side view of bag116showing beak assembly306in its inserted position through cutout210and into the interior of bag116. Gas A may continue to flow until desired but at least until exterior surface207aof first panel202has made contact with vacuum cups316. As shown inFIG. 7A, beak assembly306includes two separate arms708and710. Each arm may include a nozzle308for expelling gas introduced into beak assembly, such as through conduit318. As also shown inFIG. 7A, end effector302includes a driving mechanism702coupled to beak assembly306, which is used to cause beak assembly306to “open” or expand. Driving mechanism702may be any known combination of mechanical linkages, rods, motors, servos, gears or any pneumatic, hydraulic or other conventional method for opening or expanding the two arms708,710of the beak assembly306.

In one embodiment, driving mechanism702may include hydraulic or pneumatic cylinders704coupled to cylinder rods706. In operation, when cylinders704are energized, rods706are made to retract, or expand depending on the mechanical configuration. As shown inFIG. 7B, the retraction causes tips712of first arm708and second arm710of beak assembly306to pivot away from center axis312and each other, about base714of each arm. Tips712of each arm may be separated a distance D during expansion.

In one operational embodiment, to aid in securing bag116to end effector302, while beak assembly306is inserted into cutout210, arms708and710may be expanded a distance D, which is greater than the diameter C of cutout210. As arms708and710expand to distance D, an outer surface716of each arm708and710is made to contact an inner surface of cutout210. The continuing expansion of arms708and710to distance D causes a portion of bag116proximate to cutout210to migrate up along arms708and710. Because distance D is greater than diameter C of cutout210, tips712and at least a portion of arms708and710are positioned securely within the interior of bag116. The expanded tips712and arms708and710secure bag116to end effector302.

As shown inFIGS. 1 and 8A, once bag116has been secured to end effector302, the end effector retreats up to its initial position, thereby lifting bag116from bag stack118. As shown inFIG. 8B, in one embodiment, beak assembly306includes a pusher mechanism802. For example, pusher mechanism802may reside within beak assembly306between arms708and710. As end effector302ascends to its initial position, pusher mechanism802may be deployed by being extended in the opposite direction and made to contact interior surface207bof second panel204. Since end effector302is pulling substantially on first panel202of bag116, the extension of pusher mechanism802against the interior surface207bof second panel204causes pusher mechanism802to separate the two sides202and204and further force open bag116. In one embodiment, pusher mechanism802may be a hollow rod, which can serve the dual purpose of pusher mechanism802and conduit318for providing the gas fed into beak assembly306as previously described.

FIG. 8Cis a schematic side view of the end effector302and bag116ofFIG. 8B. In a further aspect, a support feature500is incorporated proximate the open end206of the bag116. The support feature500may be programmed to cooperate with the end effector302to further support the bag. For example, with reference toFIG. 8D, the support feature may be an actuator configured for pushing a rod or shaft502into the opening206of the bag116to support the bag at a location spaced from the opening. To minimize catching the rod502against the bag116, a smooth end tip504may be incorporated.

As end effector302ascends to its initial position with bag116attached, bag116is ready for further processing by bagging assembly100(FIG. 1). An exemplary operation of a bagging assembly in which bag116and bag retrieval assembly110may be incorporated is fully described in U.S. Provisional Application Ser. No. 61/033,376, which is incorporated herein by reference for all purposes.

Referring now toFIG. 9, a schematic view of an alternative bag retrieval assembly110utilizing a Cartesian coordinate robot400is shown. As is well known in the art, the robot400is programmed to be movable along an X-Y plane and up and down along a Z axis to reach a specified coordinate. The robot may, in combination with a visualization system404(FIG. 13), be used to locate and detect a mark, a blemish, a target, or more generically an indicium212, and movable to the specified coordinate identified by the visualization system upon detection of said mark, blemish, or indicium. In another embodiment, two or more indicia are incorporated on the surface of the bag. In one exemplary embodiment, a circle212is used as a mark on a first panel202of a bag116to be detected by the visualization system404, which may be a vision sensor provided by DVT Vision System, a division of Cognex Corporation. The bag116further incorporates a cut section406for use by an end effector402to pick up the bag116for further processing by the bag positioning assembly112, as further discussed below. In another embodiment, the indicium212is a reflective or darkened/colored line drawn next to the cut section. Optionally, the reflective or darkened/colored line is drawn parallel to the out section.

In one embodiment, the cut section406is a slit formed on only the first panel202of the bag116. The cut section406may be about 2 to about 12 inches in length and about 1 to 10 inches from an edge of the indicium212. Other dimensions may be incorporated without deviating from the spirit and scope of the present embodiment. However, it is understood that the cut section may represent other cut shape, such as a circle, an oval, a rectangle, etc. with a slit being more preferred. Thus, once the indica212is detected by the visualization system404, the location of the slit406relative to the indica may be computed and the robot400be programmed to move to and interact with the slit to pick up the bag, as further discussed below. Like previously described bags, the current bag embodiment has an open end206to which the indicium212and the slit406are aligned. Most preferably, the slit and the indicium are centered relative to the two side edges212dand212eof the bag116and are positioned closer to the open end206than the closed end208. In one embodiment, the slit is located about 4 to 8 inches from the open edge of the bag.

With reference now toFIGS. 10 and 11, a preferred end effector402for use with the Cartesian coordinate robot400of the present embodiment is shown. In particular,FIG. 10is a front perspective view of the end effector402whileFIG. 11is an angled isometric view of the same end effector402with a top mounting bracket408aincluded for a more complete view of the end effector.FIG. 10is shown without the top mounting bracket408ato show a pair of actuator cylinders450for manipulating an optional upper pair of spreader prongs410a,410band a pair of pickup probes412a,412b, as further discussed below. The cylinders450are configured to move the probes and the prongs between an open position (FIG. 11) and a closed position (FIG. 10). Thus, the end effector402provided in accordance with aspects of the present invention is understood to include both upper and lower mounting brackets408a.408bbut, depending on a particular application, may or may not include the optional upper pair of spreader prongs410a,410b. The probes412a,412bare more clearly shown in plan or top view inFIG. 12. The purpose and function of the optional upper pair of spreader prongs410a,410band the pickup probes412a,412bare further discussed below. In another embodiment, the end effector402uses a single pickup probe or more than two pickup probes.

Referring again toFIG. 10, in one embodiment the end effector402is a pickup head adapted to support a visualization system, for example, e.g., system404inFIG. 13. The pickup head402is also configured to grab a bag and pickup the bag for further processing by a bag positioning assembly112(FIG. 1). The pickup head402incorporates an upper and a lower mounting bracket408a,408b(lower mounting bracket shown only) having a pair of mounting blocks414a,414bdisposed therebetween. Each mounting block414incorporates a dowel or pin416upon which the pickup head pivots. The two dowels or pins416are configured to mount to an end of a Cartesian coordinate robot400(FIG. 9) or alternatively to a coupling (not shown) that is in turn coupled to the robot. One or more air cylinders (not shown) may be used to pivot the pickup head402about the two pins416to raise or lower the probe end of the pickup head, as further discussed below with reference toFIG. 16. In an alternative embodiment, the two mounting blocks414a,414bare formed as a single block or more than two blocks.

The two spreader prongs410a,410bare generally similar in configuration with one of the prongs incorporating an overhang section for covering the tip of the other prong, as further discussed below. Thus, the discussion hereinbelow regarding the spreader prongs410a,410are with reference to only one of the prongs with the understanding that it applies equally to the other. The spreader prong410acomprises two or more wing sections, which in the current embodiment includes a proximal wing section418and a distal wing section420. The two sections418,420are joined together along a corner422, which has a bore or opening424for receiving a rotatable pin426. The proximal wing section418further incorporates a second bore or opening425for receiving a second pin428. The first rotatable pin426is thus in pivoting communication with the corner opening424of the spreader prong and the corresponding opening of the pickup probe412awhile the second rotatable pin428is in pivoting communication with the outer opening425of the spreader prong410aand the corresponding opening of the pickup probe412a. The second rotable pin428is also in pivotable with both the upper and the lower mounting brackets408a,408b. Hence, when the actuator cylinder450is actuated, the piston rod on the cylinder450pushes on the inner pin426, which causes the spreader prong410aand the pickup probe412ato pivot about the outer pin428, as shown inFIG. 11. Conversely, when the actuator is de-energized and the piston rod retracts inside its cylinder, the prong410aand the probe412apivot about the outer pin428to a closed position (FIG. 10).

The distal wing section420incorporates a cutout430, which in one embodiment is a half-circle configuration that can alternatively embody other shapes, such as a half square, a half rectangle, etc. When the pickup head402is in a closed or probing position as shown inFIG. 10, the two cutouts430form a viewing window432for looking through and viewing the pickup probes412a,412b. With reference toFIG. 13, the visualization system404can therefore view through the viewing window432to determine whether the probes412a,412bare present or not to then generate a corresponding signal to a controller to perform other steps, as further discussed below.

Referring again toFIG. 12in addition toFIGS. 10 and 11, the pickup probes412a,412beach incorporates a proximal probe section434aor434band a distal probe section436aor436b. Like the spreader prong, each proximal probe section incorporates a corner opening424and an outer opening425for pivoting communication with corresponding pins426,428(FIG. 10). In one embodiment, the probe embodies a V shape configuration and has an angular proximal edge438to provide added clearance when moving to an open or pickup position (FIG. 11). A catch area440is formed along an outer edge of the proximal and distal probe sections434a,434bfor catching the bag116, as further discussed below. In one embodiment, the catch area440includes a guide edge442and a retention hook444.

Along the distal direction, the distal probe section436incorporates an enlarged catch portion446, which has an apex448and optional frictional features such as bumps, fingers, brillo pad type fabric, etc. to facilitate gripping the bag116when moving to an open bag grabbing position, as further discussed below. In one particular embodiment, one of the distal probe sections incorporate an overhang452having an undercut area454to accommodate the enlarged catch section446of an adjacent probe. The overhang452, which functions like a cap, covers a seam456that is located between the two probes412a,412b. Thus, when the pickup head402moves in the direction of the arrow458to penetrate and catch the slit406on the bag116, the chance of just one probe entering the slit or catching an object in the seam456is minimized. The various components of the preferred pickup head402may be made from metal, such as steel or stainless steel, a composite material, or a hard plastic with steel being most preferred.

The pickup process will now be discussed with reference toFIGS. 13-18. During bagging operation using the bagging assembly100as provided herein, the pickup head402is first move to an open position (FIG. 14) by activating the two actuator cylinders450(FIG. 10). The visualization system404then takes a snap shot of the bag116through the opened spreader prongs410a,410band pickup probes412a,412bto locate the position of the indica212relative to the pickup head402. A controller then uses the information captured by the visualization system402to compute the x, y, and z coordinate to then command the robot400to move to the computed coordinate.

The pickup head402is then moved to a closed position (FIG. 15) once the desired coordinate is reached by the robot. Next, one or more actuators (not shown, such as two) are actuated to tilt the pickup head402so that the tip460of the pickup probes412a,412band the tip462of the spreader prongs410a,410bstraddle the slit406on the bag116and the slit is located somewhere in between the two tips (FIG. 16). Further downward pressure and distal movement of the Cartesian coordinate robot400causes a portion of the bag on one side of the tip462to be agitated and lift open by the two spreader prongs410a,410b. With still further distal movement of the robot400, the tip460of the pickup probes412a,412benters the slit and causes a portion of the bag adjacent the slit to ride up the probes. In an alternative embodiment, the pickup head402is adjusted so that the approach angle is less steep when initiating entry of the probe into the slit.

In one embodiment, the pickup head402is configured to move a predetermined axial distance once the probe is inserted into the slit. For example, the robot may be programmed to move approximately the same distance as the distance of the distal probe section measured from the tip of the overhang452(FIG. 12) to the horizontal sections451of the proximal probe sections434a,434b. In an alternative and more preferred embodiment, the extent of movement of the robot to position the probe into the slit is controlled by the visualization system402. For example, with reference toFIG. 17, the robot400is caused to move until the probes412a,412bare no longer visible through the viewing window432by the visualization system402. This is caused by the bag riding up the probes and covering it from view, which confirms that the probe is now safely moved into the slit. At this point, the probes412a,412bare covered by the bag and no longer detectable by the visualization system, which may be programmed to interpret this information as a positive insertion of the probes into the slit. Due to the angle of the pickup head, the bag116begins to open along its open end206.

The pickup head402is now actuated to move to an open position as shown inFIG. 18. With reference also toFIG. 12, during this process, the two pickup probes410a,410bpivot about the outer pins at their respective outer opening425until stopped by the two actuator cylinders450(FIG. 10). At this point, the two edges464a,464bof the slit are captured by the retention hooks494on the two pickup probes410a,410band the bag is ready to be raised and moved away from the stack of bags.

When the bag116is raised and because it is only held on one side, the open end206of the bag opens further due to gravity. A blast of air from an appropriately placed nozzle could, if needed, assist in opening a bag made from a material that may not want to naturally separate, such as due to static elasticity or natural adhesion forces. The open end can now be entered by the positioning arms on the bag positioning assembly112(FIG. 1) to then place the bag around a chute, as discussed in application Ser. No. 61/033,376, which was previously incorporated by reference.

FIG. 19is a perspective view of a pickup head466provided in accordance with aspects of the present invention. The pickup head466is nearly identical to the pickup head402disclosed with reference toFIGS. 10-18with one exception, the spreader prongs410a,410bfor facilitating the lifting of the lip around the slit406of a bag116have been eliminated. Thus, in using the pickup head466of the present embodiment, the Cartesian coordinate robot can simply make a series of probing motion to insert the probes412a,412binto the slit without having to lift the lip of the slit406.FIGS. 19A-19Care schematic views of the alternative pickup head466moving into the slit406. In one example, a sensor (not shown) is incorporated to indicate successful entry by the pickup head466into the slit so that the next operation sequence may be initiated.

In still yet another embodiment, an end effector comprising a single probe (not shown) is used to engage a cut section of a bag to separate the bag from a roll of bags or a stack of bags. The single probe may have a barb end, a frictional tip, and/or a hook end so that once the probe enters the cut section, the probe engages the bag and may be lifted without a spreader device. Yet in another embodiment, an end effector comprising a plurality of spaced apart probes, similar to a fork, may be used to pick up a bag.

Although embodiments of the bag and bag retrieval assembly have been specifically described and illustrated, many modifications, combinations, and variations of the embodiments will be apparent to those skilled in the art. For example, the dimensions of the bag and the positioning of the robotic device within the housing may be modified to achieve their intended purpose. Furthermore, although specific features and aspects may be discussed for a particular embodiment, they are understood to be useable and may be incorporated in other embodiments provided to functions are compatible. For example, where the end effector ofFIG. 3is described as capable of moving along multiple axes or alternative is fixed for use with a movable stack of bags, the same concept may be used for end effectors ofFIGS. 9 and 19. Accordingly, it is to be understood that the bag and bag retrieval assembly constructed according to principles of this invention may be embodied other than as specifically described herein. The invention is also defined in the following claims.