A load centering device including a drive assembly that adjusts the force.

Abstract

Various embodiments of the present disclosure provide a load centering device and a method for centering a load, including a drive assembly that adjusts forces. The load centering device includes a drive assembly comprising a first drive shaft, a second drive shaft, and a torque-absorbing coupler that connects the second drive shaft to the first drive shaft. A controller is configured to determine, based on data received from a position sensor, the offset of the rotational position of the second drive shaft relative to the rotational position of the first drive shaft. In response to determining that the offset exceeds a threshold offset, the controller is configured to control the drive assembly to move the load engagers of the load centering device away from each other.

Description

Technical Field

[0001] Priority This application claims the priority and benefit of U.S. Provisional Patent Application No. 63 / 459,594, filed on April 14, 2023, the entire content of which is incorporated herein by reference.

[0002] The present disclosure relates to a luggage centering device for centering luggage on a conveyor, and more particularly, to a luggage centering device including a drive assembly for adjusting force.

Background Art

[0003] Luggage centering devices are used to center luggage on a conveyor. Generally, a luggage centering device includes two opposing centering arms and a motor that controls the centering arms to move the centering arms toward each other (in the lateral inner direction with respect to the moving direction of the luggage of the article) at the same speed so that the luggage of the article engages with the opposing side portions and centers the luggage of the article on the conveyor. Some of these conveyors are feeding conveyors that send the luggage of the article to a packaging machine, such as a stretch hood machine that packages the luggage of the article with a tubular plastic stretch film. Centering the luggage of the article on the feeding conveyor before sending the luggage of the article to the packaging machine ensures that the luggage of the article is properly positioned for packaging.

[0004] Certain types of luggage centering devices use an electric motor to control two centering arms. In these luggage centering devices, during the luggage centering process, the motor attempts to move the centering arms in the lateral inner direction until the motor stalls, at which point the luggage of the article is centered and the motor moves the centering arms outward to release the luggage of the article. The problem with this setup is that the motor stalls after the load of goods is centered and after the centering arm continues to apply force to the opposite side of the load (essentially after compressing the load). This stall occurs because the load prevents the motor from continuing to move the centering arm. This compressive action, performed after centering and before the motor stalls, could damage or even destroy the load of goods and / or the motor. [Overview of the project] [Problems that the invention aims to solve]

[0005] Various embodiments of this disclosure provide a luggage centering device that includes a drive assembly for adjusting a force that limits the force applied to the luggage by a luggage engager. [Means for solving the problem]

[0006] In one embodiment, the cargo centering device comprises a frame, a first cargo engagement arm assembly supported by the frame and comprising a first cargo engagementr, a second cargo engagement arm assembly supported by the frame and comprising a second cargo engagementr, and a drive assembly operably connected to the first and second cargo engagement arm assemblies and configured to move the first and second cargo engagementrs toward and away from each other. The drive assembly comprises a first drive shaft, a second drive shaft operably coupled to first and second load-engaging arm assemblies, a torque absorption coupler that couples the second drive shaft to the first drive shaft and includes a compressible torque absorber, and a motor operably connected to the first drive shaft to apply drive torque to the first drive shaft. The load centering device also includes a first position sensor operable to monitor the rotation of a first drive shaft and a second position sensor operable to monitor the rotation of a second drive shaft. A controller is connectable to the motor and to communicate with the first and second position sensors. The controller is configured to determine the offset at the rotational position of the second drive shaft relative to the rotational position of the first drive shaft based on first data received from the first position sensor and second data received from the second position sensor. In response to a determination that the offset exceeds a threshold offset, the controller is configured to control the drive assembly to move the first and second load engagers away from each other.

[0007] In one embodiment, a method for centering a load on a conveyor includes the step of controlling a drive assembly to move first and second load engagers toward the load, the first load engager being on the first side of the load and the second load engager being on the second side of the load. The drive assembly comprises a motor, a first drive shaft operably coupled to the motor, a second drive shaft, and a torque-absorbing coupler connecting the second drive shaft to the first drive shaft. This method includes the steps of: receiving first data from a first position sensor that monitors the rotation of a first drive shaft; receiving second data from a second position sensor that monitors the rotation of a second drive shaft; and identifying an offset at the rotational position of the second drive shaft relative to the rotational position of the first drive shaft based on the first data from the first position sensor and the second data from the second position sensor. The method also includes the steps of determining that the offset exceeds a threshold offset, and, in response to determining that the offset exceeds a threshold offset, controlling the drive assembly to move the first and second load engagers away from the load. [Brief explanation of the drawing]

[0008] [Figure 1]Figure 2 is a top plan view of one exemplary embodiment of a stretch hood machine, a feed and discharge conveyor for the stretch hood machine, and a cargo centering device of the present disclosure. [Figure 2] This is a perspective view of one embodiment of a stretch hood machine. [Figure 3] Figure 1 is a top perspective view of the cargo centering device. [Figure 4] Figure 1 is a bottom perspective view of the cargo centering device. [Figure 5] Figure 1 is a top view of the cargo centering device. [Figure 6] Figure 1 is a bottom plan view of the cargo centering device. [Figure 7] Figure 1 is a perspective view of a key part of the drive assembly of the cargo centering device. [Figure 8] Figure 1 is an exploded perspective view of a portion of the drive assembly of the cargo centering device. [Figure 9A] This is a simplified plan view showing the load of goods on the feed conveyor shown in Figure 1, and the centering arm of the load centering device shown in Figure 1 that centers the load of goods on the feed conveyor. [Figure 9B] This is a simplified plan view showing the load of goods on the feed conveyor shown in Figure 1, and the centering arm of the load centering device shown in Figure 1 that centers the load of goods on the feed conveyor. [Figure 9C] This is a simplified plan view showing the load of goods on the feed conveyor shown in Figure 1, and the centering arm of the load centering device shown in Figure 1 that centers the load of goods on the feed conveyor. [Modes for carrying out the invention]

[0009] The systems, devices, and methods described herein may be implemented in various forms, but the drawings illustrate specific exemplary and non-limiting embodiments. Not all components shown in the drawings and described in the specification are required, and a particular implementation may include additional, different, or fewer components. Modifications to the arrangement and type of components, the shape, size, and material of components, and the manner in which components are connected may be made without departing from the spirit or scope of the claims. Unless otherwise indicated, any orientation referred to herein reflects the orientation of components shown in the corresponding drawings and does not limit the scope of this disclosure. Furthermore, terms referring to mounting methods, such as mounting and connection, should be interpreted broadly to include indirect and operable mounting, connection, and similar mounting methods, not limited to direct mounting methods. This specification is intended to be interpreted as a whole and understood by those skilled in the art in accordance with the principles of this disclosure.

[0010] Various embodiments of this disclosure provide load centering devices that include a force-restricting drive assembly that limits the force applied to the load by a load engager. While load centering devices for use with feed conveyors for stretch hood machinery are shown herein, load centering devices of this disclosure can be used in other ways, for other purposes, and for other machines or systems.

[0011] Figure 1 shows a portion of an integrated packaging line, including a stretch hood machine 10, a driven feed conveyor IC, a driven delivery conveyor OC, and an example of one embodiment of the cargo centering device 100 of the present disclosure.

[0012] The stretch hood machine 10, best shown in FIG. 2, is configured to wrap a load with a segment of tubular plastic stretch film. The stretch hood machine 10 includes a machine frame 12, a film supply assembly 20 supported by the machine frame 12, a film opening assembly 30 supported by the machine frame 12, a take-up and packaging assembly 40 supported by the machine frame 12, an operator interface (not shown), and a controller (not shown).

[0013] The machine frame 12 is formed from a plurality of tubular and / or solid members and other elements (not individually labeled) and is configured to support the other assemblies and components of the stretch hood machine 10. The machine frame 12 defines a packaging area therein and has a loading area (not labeled) into which palletized loads (such as load L including the articles on pallet P) are conveyed for packaging, and an unloading area (not labeled) from which the palletized loads are conveyed after packaging. The illustrated machine frame 12 is merely one configuration example, and any suitable configuration can be adopted.

[0014] The film supply assembly 20 includes suitable components configured to form a segment of the tubular film F. These components are used by the stretch hood machine 10 to package the load L. More specifically, the film supply assembly 20 withdraws a length of the tubular film from a roll R of the tubular film rotatably attached to the machine frame 12, cuts a length of the tubular film from the roll R to form a segment of the tubular film F, and includes components suitable for closing (via a heat seal mechanism) the upper end of the segment of the tubular film. The controller determines the length of the segment of the tubular film F (partially) based on the height of the load L.

[0015] The film opening assembly 30 includes suitable components configured to open the bottom of a segment of the tubular film F and form generally rectangular perimeters in preparation for winding by the winding and packaging assembly 40. More specifically, the film opening assembly 30 includes four suction boxes (without labels) and four corresponding holding devices (without labels) that are movable inwardly and outwardly in a lateral direction relative to a segment of the tubular film F. To open the bottom of the segment of the tubular film F, the suction boxes move inwardly in the lateral direction such that they are disposed adjacent to the outer surface of the bottom of the segment of the tubular film F. A vacuum is generated to draw the bottom of the segment of the tubular film F onto the suction boxes, thereby partially opening the bottom. The holding devices then clamp the segment of the tubular film, and the suction boxes and the holding devices move outwardly in the lateral direction in preparation for winding to open the bottom of the segment of the tubular film F. At this point, the perimeter of the bottom of the segment of the tubular film F forms a generally rectangular shape in preparation for winding. This is merely an example of the film opening assembly 30, and other embodiments of the film opening assembly 30 can include any other suitable components.

[0016] The winding and packaging assembly 40 includes a packaging carriage (not shown for clarity), a packaging carriage actuator (not shown), first, second, third, and fourth winding devices (not shown), and first and second sets of winding device actuators (not shown). The packaging carriage includes a suitable frame and is movable vertically relative to the machine frame 12 between an upper position and a lower position. The packaging carriage actuator may include any suitable actuator (such as an electric or hydraulic motor) and is operably connected to the packaging carriage to move the packaging carriage between its upper and lower positions. The winding device is mounted on the frame of the packaging carriage in a substantially rectangular arrangement, and the actuator of the winding device is operably connected to the winding device to move the winding device laterally inward and outward during the winding and packaging process. The winding device includes a winding finger and an actuator, the actuator configured to wind a tubular film onto the winding finger and then remove the tubular film from the winding finger.

[0017] In certain embodiments, the worker interface (not shown) is configured to receive input from the worker and output information to the worker. The worker interface includes one or more input devices configured to receive input from the worker. In various embodiments, one or more input devices include one or more buttons (such as hard or soft keys), one or more switches, and / or a touch panel. In various embodiments, the worker interface includes a display device configured to show the worker information such as the load on the pallet, the status of the packaging operation, or parameters of the stretch hood machine 10. The worker interface may include other output devices, such as one or more speakers and / or one or more lights, instead of, or in addition to, the display device. In certain embodiments, the worker interface is formed as part of the stretch hood machine 10 and is mounted, for example, on the machine frame 12. In other embodiments, the worker interface is separate from the stretch hood machine 10.

[0018] The controller includes a processing device that is communicatively connected to the memory device. The processing device may include, but is not limited to, any suitable processing device such as a general-purpose processor, a dedicated processor, a digital signal processor, one or more microprocessors, one or more microprocessors associated with a digital signal processor core, one or more application-specific integrated circuits, one or more field-programmable gate array circuits, one or more integrated circuits, and / or a state machine. The memory device may include, but is not limited to, any suitable memory device such as read-only memory, random access memory, one or more digital registers, cache memory, one or more semiconductor memory devices, magnetic media, magneto-optical media, and / or optical media, such as integrated hard disks and / or removable memory. The memory device stores instructions that can be executed by the processing device and controls the operation of the stretch food machine 10 (for example, to perform the packaging process described below). The controller is communicatively and operably connected to the film supply assembly 20, the film opening assembly 30, and the winding and packaging assembly 40, and controls the operation of these components to perform the winding process. The controller is communicatively connected to the operator interface and (1) receives signals from the operator interface representing inputs received by the operator interface, and (2) sends signals to the operator interface to cause the operator interface to output information (e.g., display). In this exemplary embodiment, the controller is also communicatively and operably connected to the load centering device 100, in particular its motor 510, to control the operation of the load centering device 100, as will be further described below. In other embodiments, the operation of the load centering device is controlled by a controller other than the controller of the stretch hood machine.

[0019] Generally, in order to wrap a load of goods with the stretch hood machine 10, the controller controls the film supply assembly 20 to pull tubular film from the film roll R, cut the film to a certain length to form segments of tubular film F, and close the upper end of the segments of tubular film F. The controller also controls the film opening assembly 30 to open the bottom of the segments of tubular film F. The controller controls the actuators of the winding device to move the winding device laterally to each insertion position. The controller controls the actuators of the packaging carriage to raise the packaging carriage, thereby allowing the winding fingers of the winding device to receive the open bottom of the tubular film F segments. The controller then controls the actuators of the winding device to move the winding device laterally outward to each winding position. The controller controls the actuators of the winding device to wind the segments of the tubular film F onto the winding fingers. Next, the controller controls the actuators of the winding device to move the winding device laterally outward to its respective extended position, thereby extending the segments of the tubular film F so that they surround the load of goods. The controller controls the winding carriage to lower the winding carriage while controlling the actuators of the winding device, releasing the segments of the tubular film F from the winding fingers. Since the segments of the tubular film F are no longer wound up, the tubular film F returns to its unstretched size and shape, contracting laterally over the load to integrate the load and / or secure the load to the pallet.

[0020] The feed conveyor IC is a driven conveyor located upstream of the stretch hood machine 10 and is configured to transport loads of goods to the feed area of ​​the stretch hood machine 10 for packaging. The discharge conveyor OC is a driven conveyor located downstream of the stretch hood machine 10 and is configured to receive loads of goods from the discharge area of ​​the stretch hood machine 10 after packaging and move them downstream of the stretch hood machine 10. As used herein, “downstream” means direction D (Figure 1) and “upstream” means the direction opposite to direction D.

[0021] The load centering device 100, best shown in Figures 3 to 8, is configured to center the load of articles on the feed conveyor IC before the feed conveyor IC sends the load to the feed area of ​​the stretch hood machine 10. The load centering device 100 includes a frame 200, a first load engagement arm assembly 300, a second load engagement arm assembly 400, a drive assembly 500, and position sensors 630 and 640 that monitor a portion of the drive assembly 500.

[0022] The frame 200, best shown in Figures 3 to 8, is configured to support a first load-engaging arm assembly 300, a second load-engaging arm assembly 400, and a drive assembly 500. The frame 200 includes a first end member 210, a second end member 220, a first side member 230, a second side member 240, a first central member 250, a second central member 260, spaced-apart support rods 270 and 280 for the first and second arm assemblies, and a plurality of rod supports including rod supports 290 and 292. The support rods 270 and 280 of the first and second arm assemblies are connected and extend between the first end member 210 and the second end member 220, and are configured to support the first load-engaging arm assembly 300 and the second load-engaging arm assembly 400 as they move back and forth along the support rods 270 and 280 of the first and second arm assemblies (as described later). These members 210, 220, 230, 240, 250, and 260, these rods 270 and 280, and these rod supports 290 and 292 are made from any suitable material (such as metal) and are attached to one another in any suitable manner (such as by welding and / or fasteners). The frame 200 can be configured alternatively in other embodiments.

[0023] The first load engagement arm assembly 300, best shown in Figures 3 to 6, is driven by a drive assembly 500, movably mounted on a frame 200, and configured to engage with a first side of a load L (together with a second load engagement arm assembly 400) to center the load L on a feed conveyor IC. The first load engagement arm assembly 300 includes a first support arm 310, a second support arm 320, a load engager 330, and a connector 340. Support arms 310 and 320 are identical in this embodiment, but may be different in other embodiments. The first support arm 310 includes a rod holder mounting portion 312, an upward extending member 314 connected to the rod holder mounting portion 312, and an inward extending member 316 connected to the upward extending member 314. Similarly, the second support arm 320 includes a rod holder mounting portion 322, an upward extending member 324 connected to the rod holder mounting portion 322, and an inward extending member 326 connected to the upward extending member 324. The rod holder mounting portion 312 is slidably mounted and supported on the support rod 270. The rod holder mounting portion 322 is slidably mounted and supported on the support rod 280. Accordingly, the support rods 270 and 280 support the first load-engaging arm assembly 300. The load-engaging device 330 is connected to the inner ends of the support arms 310 and 320 (more specifically, to the inner ends of the inwardly extending members 316 and 326 of the support arms 310 and 320) and extends laterally relative to the support arms 310 and 320. The connector 340 is connected to the rod holder mounting portion 312, the rod holder mounting portion 322, and the respective bottom extensions (not individually labeled) of the belts 582 and 592 of the drive assembly 500, thereby enabling the drive assembly 500 to drive the first load-engaging arm assembly 300 (as described later).

[0024] The second load engagement arm assembly 400 is generally a mirror image of the first load engagement arm assembly 300, except for the connector 440. More specifically, the second load engagement arm assembly 400, best shown in Figures 3 to 6, is driven by a drive assembly 500, movably mounted on a frame 200, and configured to engage with a second side of a load L (together with the first load engagement arm assembly 300) to center the load L on the feed conveyor IC. The second load-engaging arm assembly 400 includes a first support arm 410, a second support arm 420, a load-engaging device 430, and a connector 440. The support arms 410 and 420 are identical in this embodiment, but may be different in other embodiments. The first support arm 410 includes a rod holder mounting portion 412, an upward-extending member 414 connected to the rod holder mounting portion 412, and an inward-extending member 416 connected to the upward-extending member 414. Similarly, the second support arm 420 includes a rod holder mounting portion 422, an upwardly extending member 424 connected to the rod holder mounting portion 422, and an inwardly extending member 426 connected to the upwardly extending member 424. The rod holder mounting portion 412 is slidably mounted and supported on the support rod 270. The rod holder mounting portion 422 is slidably mounted and supported on the support rod 280. Thus, the support rods 270 and 280 support the second load engagement arm assembly 400. The load engager 430 is connected to the inner ends of the support arms 410 and 420 (more specifically, to the inner ends of the inwardly extending members 416 and 426 of the support arms 410 and 420) and extends laterally relative to the support arms 410 and 420. Connectors 440 of the second load engage arm assembly 400 are connected to the respective upwardly extending portions (not separately labeled) of the belts 582 and 592 of the drive assembly 500, so that rotation of the belts 582 and 592 in a first direction (clockwise when viewed from the motor side) causes the second load engage arm assembly 400 to move inward, and rotation of the belts 582 and 592 in the opposite second direction (counterclockwise when viewed from the motor side) causes the second load engage arm assembly 400 to move outward.

[0025] The drive assembly 500, best shown in Figures 7 and 8, is operably connected to first and second load engagement arm assemblies 300 and 400, which move toward each other to center the load of articles on the feed conveyor IC. The drive assembly 500 includes a motor 510, a motor support 520, a first drive shaft 530, a second drive shaft 540, a torque-absorbing coupler 550, a first drive gear 580, a second drive gear 590, a first belt 582, and a second belt 592. In some embodiments, the drive assembly uses one or more chains instead of, or in addition to, the belts.

[0026] As best shown in Figure 8, the torque absorber coupler 550 includes a first torque absorber holder 552, a second torque absorber holder 558, and four separate but simultaneously compressible torque absorbers 556a, 556b, 556c, and 556d mounted on the first and second torque absorber holders 552 and 558. The first torque absorber holder 552 comprises a disc-shaped first base 553 and first brackets 554a, 554b, 554c, and 554d connected to and extending laterally from the first base 553. Similarly, the second torque absorber holder 558 comprises a disc-shaped second base 559 and second brackets 560a, 560b, 560c, and 560d connected to the second base 559 and extending laterally from the second base 55.

[0027] Torque absorbers 556a, 556b, 556c, and 556d are each attached by appropriate fasteners (unlabeled) to the first brackets 554a, 554b, 554c, and 554d, and to the second brackets 560a, 560b, 560c, and 560d. Specifically, (1) Torque absorber 556a is attached and extends between bracket 554a and bracket 560a. (2) Torque absorber 556b is attached and extends between bracket 554b and bracket 560b. (3) Torque absorber 556c is mounted and extends between bracket 554c and bracket 560c. (4) Torque absorber 556d is mounted and extends between bracket 554d and bracket 560d. Torque absorbers 556a, 556b, 556c, and 556d are members that can be compressed in the longitudinal direction. In this exemplary embodiment, the torque absorber is a compressible rubber cylinder, but in other embodiments, it may be any other suitable component (such as a spring). Each of the torque absorbers 556a, 556b, 556c, and 556d defines a central, longitudinally extending hole (unlabeled) sized to receive the respective fastener (unlabeled). The torque absorbers 556a, 556b, 556c, and 556d each extend along an axis lateral to the axis of rotation of the first drive shaft 530 and the second drive shaft 540.

[0028] Motor 510 is an electric motor in this exemplary embodiment, but may be any other suitable motor, which is appropriately supported by the motor support 520. Motor 510 is operably connected to the first drive shaft 530 (e.g., via a suitable gear mechanism) and configured to rotate the first drive shaft 530. Coupler 534 connects the first drive shaft 530 to the first torque absorber holder 552 of the torque absorber coupler 550, so that the first drive shaft 530, coupler 534, and first torque absorber holder 552 rotate together. The coupling 544 connects the second drive shaft 540 to the second torque absorber holder 558 of the torque absorber coupling 550, so that the second torque absorber holder 558, the coupling 544, and the second drive shaft 540 rotate together. The first drive gear 580 is fixedly connected to the second drive shaft 540 so that the first drive gear 580 rotates with the rotation of the second drive shaft 540. Similarly, the second drive gear 590 is fixedly connected to the second drive shaft 540 so that the second drive gear 590 rotates with the rotation of the second drive shaft 540.

[0029] The first belt 582 extends around the first drive gear 580 and has a freely rotatable gear, pulley, or other suitable component (not labeled) supported by the frame 200 adjacent to the second load engagement arm assembly 400, and is driven by the first drive gear 580. Similarly, the second belt 592 extends around the second drive gear 590 and has a freely rotatable gear, pulley, or other suitable component (unlabeled) supported by the frame 200 adjacent to the second load-engaging arm assembly 400 and driven by the second drive gear 590. As described above, the connector 340 of the first load-engaging arm assembly 300 is connected to the bottom extensions of the belts 582 and 592, and the connector 440 of the second load-engaging arm assembly 400 is connected to the upper extensions of the belts 582 and 592. In this configuration, the second load-engaging arm assembly moves at the same speed to each other when (1) the second drive shaft 540 (and therefore the drive gears 580, 590 and belts 582, 592) rotates in a first rotational direction (here, clockwise from the perspective view shown in Figure 3), and (2) the second drive shaft 540 (and therefore the drive gears 580, 590 and belts 582, 592) rotates in a second counter-rotational direction (here, counter-clockwise from the perspective view shown in Figure 3).

[0030] Position sensors 630 and 640 are coupled to the opposite ends of the first drive shaft 530 and the second drive shaft 540. For example, the first position sensor 630 is located at the end of the first drive shaft 530 that extends outward from the motor support 520 on the opposite side of the torque absorption coupler 550, and the second position sensor 640 is located at the end of the second drive shaft 540 that extends through the drive gear 590. Position sensors 630 and 640 each monitor the rotation of the drive shafts and provide feedback to the controller. Using signals from the position sensors, the controller determines when the load is centered and controls the drive assembly 500 to stop the inward movement of the load engagement arm assemblies 300 and 400. The controller then acts the drive assembly 500 to reverse the direction of the drive shafts 530 and 540 and to separate the load engagement arm assemblies 300 and 400 from each other. For example, the controller can rotate the motor 510 in the reverse direction or shift the gear configuration between the motor and the drive shaft in the reverse direction.

[0031] In the illustrated embodiment, position sensors 630 and 640 are configured as encoders, such as optical encoders, attached to the first drive shaft 530 and the second drive shaft 540, respectively. As the drive assembly moves forward, encoders 630 and 640 supply signals that identify changes in the rotational position of shafts 530 and 540 as the shafts rotate. For example, the encoders can generate pulses corresponding to changes in the angle of the shafts, for example, 1024 pulses per revolution. The controller monitors the pulses from encoders 630 and 640 and identifies the rotation of shafts 530 and 540 based on these pulses.

[0032] When sufficient force is applied to the load-engaging arm assemblies 300 and 400 to use the torque-absorbing coupler 550, the rotational positions of the two drive shafts 530 and 540 will shift relative to each other as the torque absorbers 556a-556d are compressed, as will be further described below. As a result, signals from the two encoders 630 and 640 identify further rotation of the first drive shaft 530 coupled to the motor 510 compared to the rotation of the second drive shaft 540 coupled to the load-engaging arm assemblies 300 and 400 encountering the resistive force formed by the load. Based on the offset in the rotational position of the second drive shaft 540 relative to the first drive shaft 530, the controller determines that the load is centered and reverses the movement of the drive assembly.

[0033] During operation, generally, when a load of articles on the feed conveyor IC is positioned between the first and second load engagement arm assemblies 300 and 400, the drive assembly 500 moves the load engagement arm assemblies 300 and 400 laterally and inward until they engage with the load of articles and are centered on the feed conveyor. Once the load of goods reaches the center, rather than moving the load toward the center of the feed conveyor IC, the load begins to compress, applying a resistive force to the load engagement assemblies 300 and 400. As will be described in more detail below, the resistive force applied by the load L to the engagers 330 and 430 of the first and second load engagement arm assemblies 300 and 400 compresses the torque absorbers 556a-556d of the torque absorber coupler 550, resulting in an offset (shift) in the rotational position of the second drive shaft 540 relative to the rotational position of the first drive shaft 530. Based on data from position sensors 630 and 640, which monitor the rotational positions of the first and second drive shafts 530 and 640 respectively, the controller identifies the offset of the drive shafts and controls the drive assembly 500 to move the load engagers 330 and 430 laterally outward to release the load of articles (located in the center) to be transported to the stretch hood machine.

[0034] Figures 9A and 9C show a load centering device 100 that centers a load L of articles on a feed conveyor IC. Initially, as shown in Figure 9A, the load engagers 330 and 430 of the first and second load engaging arm assemblies 300 and 400 are in their respective home positions, and the load L is not placed in the center of the feed conveyor IC. As shown in Figure 9B, the motor 510 begins to drive belts 582 and 592 in a first rotational direction (via the first drive shaft 530, the torque absorption coupler 550, and the second drive shaft 540), and as a result, the load engagers 330 and 430 begin to move toward each other and toward the load of articles L. Finally, load engager 330 makes contact with the load of articles L and moves toward the center of the load engager 430 and the feed conveyor IC. As shown in Figure 9C, the load engager 330 eventually moves the load L of articles into contact with the load engager 430, thereby centering the load L of articles on the feed conveyor IC. At this point, the sensors detect that the load engagers are no longer moving (either through direct detection of one or both of the load engagers 330 and 430, or through indirect detection of the second drive shaft 540), and the motor 510 begins to drive the belts 582 and 592 in a second rotational direction, thereby causing the load engagers 330 and 430 to move away from each other and return towards their home positions.

[0035] The torque-absorbing coupler 550 is configured to absorb a portion of the torque that the motor 510 applies to the first drive shaft 530 after the load engagers 330 and 430 have contacted the load L of articles and centered it on the feed conveyor IC, thereby minimizing the possibility that the load engagers 330 and 430 may damage the load L of articles after centering it but before releasing it.

[0036] As described above, the plate 553 and brackets 556a-556d of the first torque absorber holder 552 of the torque absorber coupler 550 rotate together with the first drive shaft 530, and the brackets 556a-556d apply driving torque to the torque absorbers 556a-556d of the torque absorber coupler 550. The torque absorbers 556a-556d transmit this driving torque to the brackets 560a-560d, the plate 560, and the second drive shaft 540. Torque absorbers 556a-556d (1) do not compress when motor 510 is driving the first drive shaft 530 and the resistance force applied to the first and second load engagement arm assemblies 300 and 400 is below a threshold resistance force, and (2) when motor 510 is driving the first drive shaft 530 and the resistance force applied to the first and second load engagement arm assemblies 300 and 400 reaches a threshold resistance force, the torque absorbers 556a-556d compress against brackets 560a-560d, thereby absorbing excess torque without transmitting the entire drive torque (including its excess torque) to the second drive shaft 540.

[0037] Therefore, as shown in Figure 9A, when neither of the engagers 330 and 430 of the first and second load engagement arm assemblies 300 and 400 engages with the load L, the resistance force on the engagers 330 and 340 is negligible (limited to the weight of the components and friction between the components) and is below the threshold resistance force. In this scenario, the torque absorbers 556a-556d transmit the drive torque of the first drive shaft 530 to the second torque absorber holder 558 without compression. This causes the second torque absorber holder 558, the second drive shaft 540, the drive gears 580 and 590, and the drive belts 582 and 592 to rotate, causing the inward movement of the first and second load engagement arm assemblies 300 and 400 (and thus the inward movement of the load engagementrs 330 and 430 of the first and second load engagement arm assemblies 300 and 400).

[0038] When one (but not both) of the engagers 330 and 430 of the first and second load engagement arm assemblies 300 and 400 engages with the load L, but is not yet centered, as shown in Figure 9B, the resisting force against the engagers 330 and 430 is still below the threshold resisting force. In this scenario, the torque absorbers 556s-556d still transmit the drive torque of the first drive shaft 530 to the second torque absorber holder 558 without compression. This causes the second torque absorber holder 558, the second drive shaft 540, the drive gears 580 and 590, and the drive belts 582 and 592 to rotate, resulting in further inward movement of the first and second load engagement arm assemblies 300 and 400 (and thus further inward movement of the engagers 330 and 430 of the first and second load engagement arm assemblies 300 and 400).

[0039] Both the engagers 330 and 430 of the first and second load engagement arm assemblies 300 and 400 engage with the load L, as shown in Figure 9C, and once the load L is centered, the resisting force against the engagers 330 and 430 increases rapidly until it reaches or exceeds a threshold resisting force. Once the resisting force reaches the threshold resisting force, the rotation of the first drive shaft 530 does not cause the rotation of the second drive shaft 540, but rather causes the first torque absorber holder 552 to simultaneously compress the torque absorbers 556a-556d against the second torque absorber holder 558. During compression, the torque absorber absorbs excess torque applied by the first drive shaft 530 and prevents that excess torque from being transmitted to the second drive shaft 540. As the torque absorbers 556a-556d are compressed, the first drive shaft 530 rotates while the second drive shaft 540 remains fixed, resulting in a difference in the rotational position of the second drive shaft 540 relative to the first drive shaft 530. The controller can identify the offset in the rotational position of the second drive shaft 540 relative to the first drive shaft 530 and actuate the drive assembly to reverse and push the load engagement arm assemblies 300 and 400 outward.

[0040] In particular, the controller operates to reverse the drive assembly 500 when the offset in rotational position between the drive shafts exceeds a threshold offset. The amount of compression received by the torque absorbers 556a-556d correlates with the resistance force exerted by the load on the load engagement arm assemblies 300 and 400. As the resistance force increases, the torque absorbers 556a-556d are compressed further. Similarly, as the torque absorbers 556a-556d are further compressed, the rotational offset between the two drive shafts 530 and 540 increases accordingly. Therefore, exceeding the threshold resistance force that causes the compression of the torque absorbers 556a-556d, the rotational offset between the drive shafts 540 and 530 correlates with the resistance force exerted by the load on the load engagement arm assemblies 300 and 400. Thus, by setting a limit on the rotational offset between the drive shafts 530 and 540, the controller can limit the force exerted on the load by the drive assemblies and load engagement arm assemblies 300 and 400.

[0041] The torque absorption coupler can be (a) different quantities of torque absorbers, torque absorber holders, brackets, and / or plates, (b) different configurations and / or sizes of torque absorbers, torque absorber holders, brackets, and / or plates, and / or (c) different arrangements of torque absorbers, torque absorber holders, brackets, and / or plates, or other suitably configured.

[0042] Furthermore, the illustrated embodiment includes a torque absorption coupler with a torque absorber that compresses once it exceeds a threshold resistance force, but in other embodiments, the load centering device includes a torque absorption coupler with a torque absorber that deforms over a wider range of applied forces. For example, in some embodiments, the torque absorber compresses a first amount when a force is applied that is used to move the load toward the center of the feed conveyor, resulting in a first offset in the rotational position of the second drive shaft relative to the first drive shaft. However, if this first offset is below the threshold offset, the controller continues to apply this force, thereby moving the load toward the center of the feed conveyor. Once the load reaches the center of the feed conveyor, the resistance force against the load engagement arm assembly increases, as described above, further compressing the torque absorber in response to the increased force. As the torque absorber is further compressed, the offset of the rotational position of the second drive shaft relative to the first drive shaft also increases in response to the increased force. If the threshold offset based on the desired force threshold is exceeded, the controller can operate the drive assembly to reverse the direction of the load engagement.

[0043] Furthermore, while the torque-absorbing coupler described uses a compressible torque absorber, in other embodiments the torque-absorbing coupler uses a torque absorber configured to absorb torque when placed under tension or deformed under torsion.

[0044] In some embodiments, the controller recognizes the initial positions of the load-engaging arm assemblies 300 and 400, as well as the relationship between the rotation of the drive shafts 530 and 540 and the movement of the load-engaging arm assemblies 300 and 400. Thus, by calculating the pulses received from at least one of the encoders 630 / 640, the controller identifies the position of the load-engaging arm assemblies 300 and 400 when the drive assembly 500 is actuated. For example, the rotation of the second drive shaft 540 directly moves the drive belts 582 and 592 via the drive gears 580 and 592. Furthermore, the load-engaging arm assemblies 300 and 400 are connected to the drive belts 582 and 592, and therefore the position of the load-engaging arm assemblies 300 and 400 can be determined based on the rotation of the second drive shaft 540. For example, the controller can recognize each rotation of the second drive shaft 540 as corresponding to a constant length of linear movement of the load-engaging arm assemblies 300 and 400.

[0045] Alternatively, in some embodiments, the controller tracks the positions of the load-engaging arm assemblies 300 and 400 using the rotation of a first drive shaft 530, which also rotates along with the movement of the load-engaging arm assemblies. To improve the accuracy of this position tracking, in some embodiments, the controller takes into account an offset identified between a second drive shaft 540 and the first drive shaft 530. Taking into account the first drive shaft 530, which is connected to the second drive shaft 540 via the torque absorption coupler 550, when the torque absorbers 556a-556d are compressed, the first drive shaft 530 is offset from the second drive shaft 540. Therefore, by adding the offset between the drive shafts to the rotational position of the first drive shaft 530, any fluctuations caused by the compression of the torque absorbers can be taken into account.

[0046] In other embodiments, the controller only determines the rotational offset in the drive shafts 530 and 540 using encoders 630 and 640, and does not track the positions of the load-engaging arm assemblies 300 and 400. In such embodiments, the controller does not recognize the positions of the load-engaging arm assemblies 300 and 400, and regardless of the positions of the load-engaging arm assemblies 300 and 400, reverses the direction of the drive shafts 530 and 540 when the rotational offset between the drive shafts exceeds a threshold.

[0047] In some embodiments, the controller is configured to stop the inward movement of the load engager based on a relative offset in the rotational positions of the drive shafts 530 and 540, independently of the position of the load engager. In other words, in some embodiments, regardless of the size of the load placed in the center, the drive assembly will act to reverse the load engager whenever a consistent threshold offset in the rotational position of the drive shafts is exceeded. In other embodiments, the controller dynamically changes the threshold offset at the rotational position of the drive shaft based on the tracked position of the load engager. For example, if a load centering device centers loads of two different sizes, in which case some of the loads are of a first larger size and relatively heavy, and others are of a second smaller size and fragile, the controller can be configured to change the threshold offset at the rotational position of the drive shaft as the load engager moves inward. Therefore, if the load engagers are far apart and there is no risk of crushing smaller loads, the offset threshold used by the controller can be set relatively high to accommodate sufficient force to move larger, heavier loads. Once the distance between the load engagers falls below the size of the larger load (indicating that the current load is one of the smaller loads), the offset threshold can be reduced, and as a result, the force applied to smaller, more vulnerable loads is limited when they come to the center.

[0048] Accordingly, in various embodiments, the present disclosure provides a luggage centering device comprising a frame, a first luggage engaging arm assembly supported by the frame and comprising a first luggage engaging device, and a second luggage engaging arm assembly supported by the frame and comprising a second luggage engaging device. The load centering device also includes a drive assembly operably connected to first and second load engagement arm assemblies and configured to move the first and second load engagementrs toward and toward each other. The drive assembly includes a first drive shaft, a second drive shaft operably connected to first and second load engagement arm assemblies, a torque absorption coupler that connects the second drive shaft to the first drive shaft and includes a compressible torque absorber, and a motor operably connected to the first drive shaft to apply drive torque to the first drive shaft. The cargo centering device further includes a first position sensor operable to monitor the rotation of a first drive shaft, a second position sensor operable to monitor the rotation of a second drive shaft, a motor, and a controller communicatively connectable to the first and second position sensors. The controller is configured to determine an offset of the rotational position of the second drive shaft relative to the rotational position of the first drive shaft based on first data received from the first position sensor and second data received from the second position sensor, and to control the drive assembly to move the first and second cargo engagers apart from each other in response to a determination that the offset exceeds a threshold offset.

[0049] In these various embodiments of the load centering device, the offset in the rotational position of the second drive shaft relative to the rotational position of the first drive shaft correlates to the resistance force applied to at least one of the first and second load engagers.

[0050] In various such embodiments of this luggage centering device, the controller determines the positions of the first and second luggage engagers based on at least one of the first data and the second data.

[0051] In these various embodiments of the cargo centering device, the threshold offset is based on the positions of the first and second cargo engagers.

[0052] In these various embodiments of the cargo centering device, the threshold offset has a first value when the first and second cargo engagers are in a first range of positions, and a second value when the first and second cargo engagers are in a second range of positions.

[0053] In these various embodiments of the cargo centering device, the first position sensor includes an encoder coupled to a first drive shaft.

[0054] In these various embodiments of the cargo centering device, the second position sensor includes an encoder coupled to a second drive shaft.

[0055] In these various embodiments of the cargo centering device, the torque absorber is a compressible torque absorber.

[0056] In these various embodiments of the load centering device, the compressible torque absorber has such rigidity that it compresses when the resistance force applied to at least one of the first and second load engagers reaches a threshold resistance force.

[0057] In various embodiments, the Disclosure provides a method for centering a load on a conveyor. The method includes the step of controlling a drive assembly to move first and second load engagers toward a load, the first load engager being on the first side of the load and the second load engager being on the second side of the load. The drive assembly comprises a motor, a first drive shaft operably connected to the motor, a second drive shaft, and a torque-absorbing coupler connecting the second drive shaft to the first drive shaft. Furthermore, this method includes the steps of receiving first data from a first position sensor that monitors the rotation of a first drive shaft, receiving second data from a second position sensor that monitors the rotation of a second drive shaft, and identifying the offset at the rotational position of the second drive shaft with respect to the rotational position of the first drive shaft based on the first data from the first position sensor and the second data from the second position sensor. The method also includes the steps of determining that the offset exceeds a threshold offset, and, in response to determining that the offset exceeds a threshold offset, controlling the drive assembly to move the first and second load engagers away from the load.

[0058] In various such embodiments of this method, the offset in the rotational position of the second drive shaft relative to the rotational position of the first drive shaft correlates to the resistive force applied to at least one of the first and second load engagers.

[0059] In various such embodiments of this method, the method further includes the step of determining the positions of first and second load engagers based on at least one of first data and second data.

[0060] In various such embodiments of this method, the method further includes the steps of: controlling a drive assembly to move first and second load engagers toward a second load; identifying a second offset in the rotational position of the second drive shaft relative to the rotational position of the first drive shaft based on first data from a first position sensor and second data from a second position sensor; determining that the second offset exceeds a second threshold offset; and controlling the drive assembly to move the first and second load engagers toward the second in response to the determination that the second offset exceeds a second threshold offset.

[0061] In various such embodiments of this method, the method further includes the steps of determining that the offset exceeds a threshold offset when the load engager is in a first position, and determining that the second offset exceeds a second threshold offset when the load engager is in a different position.

[0062] In various such embodiments of this method, the value of the threshold offset is different from the value of the second threshold offset.

[0063] In these various embodiments of the method, the first position sensor includes an encoder coupled to a first drive shaft.

[0064] In these various embodiments of the method, the second position sensor includes an encoder coupled to a second drive shaft.

[0065] In these various embodiments of this method, the torque absorber is a compressible torque absorber.

[0066] In these various embodiments of the method, the compressible torque absorber has such rigidity that it compresses when the resistance force applied to at least one of the first and second load engagers reaches a threshold resistance force.

[0067] In various such embodiments of this method, the offset exceeds a threshold when both load engagers engage with the load.

[0068] Various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. These changes and modifications can be made without departing from the spirit and scope of the subject matter and without diminishing the intended benefits. Not all illustrated components described herein are required, and some implementations may include additional, different, or fewer components than those explicitly described herein. The arrangement and type of components, the shape, size, and material of components, and the methods of mounting and connecting components can be carried out without departing from the spirit or scope of the claims described herein. Furthermore, unless otherwise specified, any orientation referred to herein reflects the orientation of components shown in the corresponding drawings and does not limit the scope of this disclosure. This specification is intended to be interpreted in whole, as taught herein and understood by those skilled in the art, and to be interpreted in accordance with the principles of the present invention.

Claims

1. A luggage centering device, Frame and, A first load-engaging arm assembly supported by a frame and equipped with a first load-engaging device, A second load-engaging arm assembly, supported by the frame and equipped with a second load-engaging device, A drive assembly operably connected to first and second load-engaging arm assemblies and configured to move the first and second load-engaging arms toward and toward each other, wherein the drive assembly The first drive shaft and A second drive shaft operably coupled to the first and second load-engaging arm assemblies, A torque-absorbing coupler is provided, which connects the second drive shaft to the first drive shaft and includes a torque absorber. A drive assembly comprising: a motor operably connected to the first drive shaft to apply drive torque to the first drive shaft; A first position sensor that is operable to monitor the rotation of the first drive shaft, A second position sensor that can operate to monitor the rotation of the second drive shaft, A cargo centering device comprising: a motor, a first position sensor, and a second position sensor, a controller configured to communicate with the motor, determine an offset between the rotational position of the second drive shaft and the rotational position of the first drive shaft based on first data received from the first position sensor and second data received from the second position sensor, and to control the drive assembly to separate the first and second cargo engagers in response to the determination that the offset exceeds a threshold offset.

2. The cargo centering device according to claim 1, wherein the offset at the rotational position of the second drive shaft with respect to the rotational position of the first drive shaft is related to the resistance force applied to at least one of the first and second cargo engagers.

3. The luggage centering device according to claim 1, wherein the controller determines the positions of the first and second luggage engagers based on at least one of the first data and the second data.

4. The luggage centering device according to claim 3, wherein the threshold offset is based on the positions of the first and second luggage engagers.

5. The luggage centering device according to claim 4, wherein the threshold offset has a first value when the first and second luggage engagers are in a first range of positions, and has a second value when the first and second luggage engagers are in a second range of positions.

6. The cargo centering device according to claim 1, wherein the first position sensor includes an encoder coupled to the first drive shaft.

7. The luggage centering device according to claim 6, wherein the second position sensor includes an encoder coupled to the second drive shaft.

8. The load centering device according to claim 1, wherein the torque absorber is a compressible torque absorber.

9. The load centering device according to claim 8, wherein the compressible torque absorber has rigidity such that it compresses when the resistance force applied to at least one of the first and second load engagers reaches a threshold resistance force.

10. A method for centering cargo on a conveyor belt, A step of controlling a drive assembly to move first and second load engagers toward a load, wherein the first load engager is on the first side of the load and the second load engager is on the second side of the load, and the drive assembly includes a motor, a first drive shaft operably coupled to the motor, a second drive shaft, and a torque-absorbing coupler connecting the second drive shaft to the first drive shaft. A step of receiving first data from a first position sensor that monitors the rotation of the first drive shaft, A step of receiving second data from a second position sensor that monitors the rotation of the second drive shaft, A step of determining the offset of the rotational position of the second drive shaft relative to the rotational position of the first drive shaft based on first data from the first position sensor and second data from the second position sensor, A process to determine if the offset exceeds the threshold offset, A method comprising the step of controlling a drive assembly to move first and second load engagers away from a load in response to determining that the offset exceeds a threshold offset.

11. The method according to claim 10, wherein the offset at the rotational position of the second drive shaft with respect to the rotational position of the first drive shaft is related to the resistance force applied to at least one of the first and second load engagers.

12. The method according to claim 10, further comprising the step of determining the positions of the first and second load engagers based on at least one of the first and second data.

13. A step of controlling a drive assembly to move the first and second load engagers toward the second load, A step of identifying a second offset in the rotational position of the second drive shaft relative to the rotational position of the first drive shaft, based on first data from a first position sensor and second data from a second position sensor, A step of determining whether the second offset exceeds the second threshold offset, The method according to claim 12, further comprising the step of controlling the drive assembly to move the first load engager away from the second load engager in response to determining that the second offset exceeds a second threshold offset.

14. The method according to claim 13, wherein the step of determining that the offset exceeds the threshold offset is performed when the load engager is in a first position, and the step of determining that the second offset exceeds the second threshold offset is determined when the load engager is in a different position.

15. The method according to claim 14, wherein the value of the threshold offset is different from the value of the second threshold offset.

16. The method according to claim 10, wherein the first position sensor includes an encoder connected to the first drive shaft.

17. The method according to claim 16, wherein the second position sensor includes an encoder connected to the second drive shaft.

18. The method according to claim 10, wherein the torque absorber is a compressible torque absorber.

19. The method according to claim 18, wherein the compressible torque absorber has rigidity such that it compresses when the resistance force applied to at least one of the first and second load engagers reaches a threshold resistance force.

20. The method according to claim 10, wherein the offset exceeds the threshold when both load engagers engage with the load.

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