Patent Application
20240336464
The present disclosure relates to automated object handling technology, and more particularly, to container lifting devices and methods for lifting containers.
Cardboard boxes and other containers are extensively employed for transporting various types of goods. These boxes are tightly packed and stacked in the back of trucks or box holders. Unloading such stacked boxes is a labor-intensive process that is common in many supply chains. This involves workers climbing into the trucks or the box holders in a warehouse and manually picking up each box and placing them on a conveyance mechanism. Therefore, there is a need for a container-lifting device that can rapidly, accurately, and efficiently unload high-stacking boxes.
Embodiments disclosed herein are directed to methods and devices for picking up containers, such as boxes. In accordance with one embodiment of the present disclosure, a container-lifting device may include a lifting fork having a front end and a back end, a friction contact surface, and a passive lifting mechanism having a first end and a second end. The first end of the passive lifting mechanism may engage the lifting fork between the front end and the back end, and the second end of the passive lifting mechanism may be coupled to the friction contact surface. The friction contact surface may be configured to lift a target container. The lifting fork may be configured to slide underneath the target container when the container is lifted. The passive lifting mechanism may transfer a fraction of a forward momentum of the container-lifting device into an upward momentum at the second end, and the friction contact surface lifts the target container by applying an upward friction force to one or more sides of the target container as a result of the upward momentum.
In accordance with another embodiment of the present disclosure, a method may include approaching a target container at a forward momentum of the container-lifting device including a lifting fork having a front end and a back end, a friction contact surface, and a passive lifting mechanism having a first end and a second end, wherein the first end of the passive lifting mechanism engages the lifting fork between the front end and the back end, and the second end of the passive lifting mechanism is coupled to the friction contact surface; contacting, using the friction contact surface, a front side of the target container; transferring, using the passive lifting mechanism, a fraction of the forward momentum into an upward momentum at the second end such that the friction contact surface applies an upward friction force to the front side of the target container and lifts the front side of the target container; sliding the lifting fork underneath the front side of the target container; and extracting the target container on the lifting fork.
These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings.
The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
The embodiments disclosed herein include devices and methods for unloading stacked containers using a mechanical container-lifting device. A container-lifting device is a device that is used to extract containers or other objects from a storage area. The specific type of container-lifting device used will depend on the size and weight of the containers being lifted, as well as the location and layout of the storage area. In an environment of a warehouse or on the back of trucks, containers are tightly packed, therefore presenting challenges such as being hard to reach, limited space to move around, being time-consuming, and having difficulty in grasping a wide variety of containers. A common approach to dealing with these challenges is to use an array of suction cups, paired with one or more strong vacuum pumps to pick up the containers and move them around. However, a container-lifting system using suction technologies is limited by several drawbacks. For example, the vacuum pumps and the required hoses add complexity and cost to the system. In order to keep the system operating smoothly, it is recommended to regularly maintain and replace vacuum pumps. Battery life becomes an issue considering the high demands of sucking power such as in a forklift.
The embodiments described herein are directed to container-lifting devices that are passive, driven only by their relative motion with respect to the container it is lifting. The container-lifting devices described herein do not require a vacuum pump or any other additional power source. Further, the container-lifting device is compatible with different systems and may be mounted to a robot arm as a mechanical end-effector, a human-operated push-cart, a forklift, or a palletizer.
When the container-lifting device is used in a robot arm system, it can be used in a depalletization process. Depalletization involves unloading containers from container holders or pallets one by one, using artificial intelligence to recognize and handle individual containers. This differs from classic delayerization, in which a robot gripper lifts the entire pallet, risking missing some containers. Robotic depalletization offers several advantages over delayerization, including the need for a smaller placement area and a lighter payload, which allows for the use of a smaller robot arm and gripper. These factors can result in significant cost savings. A robot system equipped with the mechanical container-lifting device may place each container individually onto a conveyor belt or other predetermined location, providing a higher level of precision in the unloading process.
Referring initially to
The first ends 106, 108 of the first and second passive lifting mechanisms 116, 118 are configured to move along the first and second lifting fork 102, 104 toward the front ends 112, 114 or the back ends 122, 124 on tracks 132, 134. The first end 106 of the first passive lifting mechanism 116 may be pivotally coupled to the first lifting fork 102 between the front end 112 and the back end 122 of the first lifting fork 102. Similarly, the first end 108 of the second passive lifting mechanism 118 may be pivotally coupled to the second lifting fork 104 between the front end 114 and the back end 124 of the second lifting fork 104. Particularly, the first and second passive lifting mechanisms 116, 118 may transfer a fraction of a forward momentum of the container-lifting device 100, when the container-lifting device 100 moves toward a target container 202, into an upward momentum at the second ends 126, 128. The friction contact surface 127 may lift the target container 202 by applying an upward friction force on the front side of the target container 202 as a result of the upward momentum.
A forward momentum presents a forward velocity indicating the container-lifting device 100 is moving toward a target container 202 as in
The first end, such as the first end 106 of the first passive lifting mechanism 116 and the first end 108 of the second passive lifting mechanism 118 are coupled to the first and second lifting forks 102, 104. In embodiments, the first lifting fork 102 and the second lifting fork 104 may be coupled to a sliding bar 107, which is configured to slide back and forth along the length of the first and second lifting forks 102, 104. As shown in
In embodiments, the second ends 126, 128 of the first and second passive lifting mechanisms 116, 118 engage with the friction contact surface 127. The friction contact surface 127 may be in the shape of a bar or clamp that may contract one or more sides of the target container 202 (or other containers). A selected shape of the friction contact surface 127 may achieve a high contact area between the friction contact surface 127 and the target container 202. The friction contact surface 127 may be configured to lift a front side of a target container during the process of lifting and extracting the target container 202. When the friction contact surface 127 lifts the target container 202, the first and second lifting forks 102, 104 are operable to slide underneath the target container 202.
The friction contact surface 127 may have a friction coefficient factor of at least 0.1. In some embodiments, the friction coefficient factor of the friction contact surface 127 may be at least 0.2, or at least 0.3, or at least 0.4, or at least 0.5, or at least 0.6, or at least 0.7, or at least 0.8, or at least 0.9, or at least 1.0, or at least 1.1, or at least 1.2, or at least 1.3. The friction coefficient factor may be a static friction coefficient factor or a kinetic friction coefficient factor. A static friction coefficient factor depicts static friction that keeps an object up to the point that the object just starts moving. A kinetic friction coefficient factor is the ratio of the friction force to the normal force, depicting the friction force that resists the motion of an object.
The friction contact surface 127 may include, without limitation, rubber, thermoplastic elastomer (TPE), and/or neoprene fabric. In some embodiments, the friction contact surface 127 may have a friction coating. The friction coating may comprise two-dimensional materials, such as, without limitation, MoS2, graphite, and boron nitride.
In embodiments, as illustrated in
In embodiments, the first and second rollers 136, 138 may further comprise a bearing that allows the wheel to rotate smoothly and efficiently by reducing friction and wear between the moving parts of the first and second rollers 136, 138. The bearing may consist of two rings with small metal balls or rollers between them. The first and second rollers 136, 138 may also comprise a shaft, which may be a long, cylindrical component that connects the wheel and bearing to the first and second passive lifting mechanisms 116, 118. The shaft may be, without limits, made of metal. The shaft may be designed to transmit torque from the first and second passive lifting mechanisms 116, 118 to the wheel, causing it to rotate.
The first and second rollers 136, 138 may transfer the forward momentum in X direction into the upward movement by moving onto the first and second lifting forks 102, 104. The first and second rollers 136, 138 may provide an efficient means of transferring the motion of the first and second rollers 136, 138 to the first and second passive lifting mechanisms 116, 118 in accordance with the surface being rolled on. By coupling the shaft to the first and second passive lifting mechanisms 116, 118, the first and second rollers 136, 138 may be lifted when the first and second rollers 136, 138 moves onto the first and second lifting forks 102, 104, causing the momentum transition from forward momentum to upward momentum. In embodiments, the forward momentum may be transferred into the upward movement using a lever mechanism. As illustrated in
The container-lifting device 100 may employ different types of passive lifting mechanism to transfer the forward momentum into the upward movement. For example, the container-lifting device 100 may comprise a passive lifting mechanism using a rubber drum system or a hydraulic system.
Referring to
In embodiments, the lifting fork 102 or 104 may be, without limitation, a standard fork, a block fork, a telescopic fork, a scale fork, a bolt-on fork, a tire fork, a corrugated fork, a peek-a-boo (PAB) fork, or a pallet fork. The container-lifting device 100 may include a tray in replace of the first and second lifting forks 102, 104. The tray may include a left plane, right plane and a bottom plane. The left plane and the right plane may have comparable structures as the first and second lifting forks 102, 104 as described herein.
The container-lifting device 100 may further include a mount flange 123 coupled to the back ends 122, 124 of the first and second lifting forks 102, 104. The mount flange 123 may be configured to be coupled to a robot arm, a forklift, or a palletizer.
It is noted that it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. It is also noted that it will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the scope of the claimed subject matter.
In embodiments, a stack of containers 201 (or other containers), including a target container 202 and one or more additional containers 212, may be closely packed and stored on a container stack holder 204. The container stack holder 204 may be located in a warehouse or on the back of a truck. During the process, the lifting fork 102 may be adjusted to match the width of the target container 202.
Referring to
Referring to
In embodiments, the roller 136 may provide an efficient means of transferring the motion of the roller 136 to the passive lifting mechanism 116 in accordance with the surface being rolled on. The roller 136 may be lifted when the roller 136 moves from the ground surface onto the inclined plane at the front end 112 of the lifting fork 102, causing the momentum transition from forward momentum to upward momentum. The passive lifting mechanism 116 may function as a lever with the first end 106 as a fulcrum, which cannot freely move in the vertical direction. When the roller 136 moves onto the lifting fork 102, an effort is provided on the passive lifting mechanism 116, causing an upward motion such that the friction contact surface 127, which is attached to the second end 126, moves upward.
Referring to
Referring to
It is also noted that recitations herein of “at least one” component, element, etc., should not be used to create an inference that the alternative use of the articles “a” or “an” should be limited to a single component, element, etc.
It is noted that recitations herein of a component of the present disclosure being “configured” or “programmed” in a particular way, to embody a particular property, or to function in a particular manner, are structural recitations, as opposed to recitations of intended use. More specifically, the references herein to the manner in which a component is “configured” or “programmed” denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural characteristics of the component.
Having described the subject matter of the present disclosure in detail and by reference to specific embodiments thereof, it is noted that the various details disclosed herein should not be taken to imply that these details relate to elements that are essential components of the various embodiments described herein, even in cases where a particular element is illustrated in each of the drawings that accompany the present description. Further, it will be apparent that modifications and variations are possible without departing from the scope of the present disclosure, including, but not limited to, embodiments defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.
