Pallet moving device

Abstract

A pallet moving device (1) for moving a pallet (18), the pallet (18) having a top deck formed from one or more planks and a lower deck formed from one or more planks, the lower deck being spaced apart from the top deck, the pallet moving device comprising: a body (2) having a lifting mechanism and a drive assembly for moving the pallet moving device; and a plurality of forks (4) for lifting and handling the pallet, wherein the plurality of forks (4) extend outward from the body (2) and are lifted by the lifting mechanism. a first set of wheels (10) and a second set of wheels (12), each of the first and second sets of wheels being independently movable relative to the plurality of forks (4), and the first set of wheels (10) being configured to be vertically movable between a stowed position in which it disengages from the floor and a deployed position in which it engages the floor, in use, such that the first set of wheels (10) clears one or more planks of the pallet (18) when the plurality of forks are inserted into the pallet (18).

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to vehicles, and more particularly to pallet moving devices that may be operated in storage facilities such as warehouses or fulfillment centers. [Background technology]

[0002] Many goods are transported and / or stored on pallets. Pallets come in a variety of types, generally comprising a top deck, typically formed from a series of planks, otherwise known in the art as runners, and a lower deck separated from the top deck by wooden blocks. Like the top or upper deck, the lower deck is typically formed from a series of planks nailed to the wooden blocks to improve the pallet's rigidity. Such pallets are commonly referred to as block or deckboard pallets. Instead of using blocks to separate the top and lower decks, planks disposed perpendicular to the planks on the top deck may be used to separate the top deck from the lower deck. The spacing between the top and lower decks may be arranged to allow forklift truck or pallet truck forks to enter the pallet in two or four directions, whereby a four-way pallet allows the pallet truck forks to enter the pallet through all four sides, while a two-way pallet only allows the pallet truck forks to enter the pallet through two sides. For obvious reasons, a four-way pallet is the most common type of pallet. There are two main styles of pallets that allow fork entry in four directions. These are commonly known as open pallets and full perimeter pallets. Open pallets usually have three planks or runners that run longitudinally through the lower deck of the pallet, while in full perimeter pallets, the runners or planks in the lower deck are connected at their respective ends to spacers.

[0003] There are various types of pallet trucks known in the art for moving pallets, which are generally classified as either manual or powered. Manual pallet trucks typically have a frame or body from which forks extend, a truck supported on a pair of rear wheels, and a hydraulic jack connected to the truck and frame or body. The jack, typically a hydraulic bottle jack, is operated by pivotally pumping the steering handle of the pallet truck up and down, which causes the hydraulic bottle jack to raise the frame and thus the forks off the ground. Once the pallet is raised by pumping the handle, the operator can steer the pallet truck by turning the handle relative to the truck. To maneuver the pallet truck over the ground, the hydraulic jack typically has one or more steering wheels, and each fork usually has either a single wheel or two wheels at the front of the pallet truck. The front wheels are usually inside the forks and are mounted on a lever attached to a linkage that leads to a lever attached to the hydraulic jack. When the hydraulic jack is raised (as a result of pumping the handle), the linkage pushes down the front wheels, which in turn raises the forks vertically above the wheels and the load in the forks upward until it no longer touches the floor. Mounting the front wheels on the lever prevents the pallet truck from tipping over when the pallet truck frame connected to the forks is lifted by the hydraulic jack. Compared to manual pallet trucks, the hydraulic jack and / or steering wheels are motorized in powered pallet trucks to enable heavier stacked pallets to be lifted and moved. Powered pallet jacks are generally operated by a throttle on the handle to move forward or backward and are steered by swinging the handle in the intended direction. As with manual pallet trucks, wheels are mounted on the front of the forks to prevent the powered pallet truck from tipping, especially when the pallets are carrying heavy loads.

[0004] Instead of mounting wheels on the front of the forks, the weight of the power pallet truck's body can be made large enough to counterbalance any load lifted by the forks to prevent the power pallet truck from tipping. Such power pallet trucks have J-shaped forks configured to fit into the gap between the upper and lower decks of the pallet. Without additional weight on the power pallet truck's body, there is a risk that the powered pallet truck may tip over when lifting heavy loads. In some cases, the power pallet truck's body is intentionally made heavy, for example, using cast iron weights, to counterbalance any weight lifted by the forks. Alternatively, an arrangement similar to that of a manual pallet truck can be employed, in which each wheel is mounted on the front of the forks via a lever that extends the wheels vertically when the forks are raised to prevent the pallet truck from tipping over.

[0005] However, installing wheels inside the forks via levers connected to a hydraulic jack has drawbacks when attempting to insert the forks into a pallet. This is because the wheels must climb over planks in the lower deck of the pallet so that the forks can be inserted into the space between the top and bottom decks of the pallet. In some cases, the pallet truck operator must forcefully push the pallet forks with enough force to force the front wheels over one or more planks in the lower deck of the pallet. Once the forks are inserted into the pallet gap, the operator can then lift the pallet off the ground by pumping the hydraulic jack as discussed above. Depending on the thickness of the planks in the lower deck of the pallet, this force can be great enough to require the operator to take a running start to climb over the planks in the lower deck of the pallet. Movement of the forks during insertion into the pallet can also cause damage to the pallet, the extent of which depends on the speed of the forks as they are inserted into the pallet.

[0006] A well-run warehouse is well-organized and maintains an accurate inventory of goods. Goods may frequently enter and leave a warehouse throughout the day. Some large, highly congested warehouses operate three shifts, continuously moving goods throughout the warehouse as orders are received or needed to fulfill them. The trend toward automation and unmanned production systems in the transportation industry has led to the increased use of automated guided vehicles (AGVs) responsible for transporting products within warehouses. AGVs are mobile robots that follow markers or wires on the floor, or use vision or lasers to navigate without direct or remote control by an operator. The body of an autonomous forklift truck includes a drive mechanism and a lift mechanism for autonomously lifting a pallet and any items supported thereon and moving the forklift truck throughout the warehouse. Similar to manual and powered pallet trucks, autonomous forklift trucks include forks with wheels inside the forks configured to be inserted into a pallet.

[0007] The force required by the inner wheels of the forks is variable and highly dependent on the thickness of the planks in the lower deck of the pallet. Providing sufficient force for the inner wheels of the forks to overcome one or more planks in the lower deck of the pallet not only requires a drive mechanism that provides sufficient torque for the wheels to overcome one or more planks, but also introduces more complexity into the drive mechanism of the autonomous pallet truck. To overcome the need for the inner wheels of the forks to overcome one or more planks in the lower deck of the pallet, the forks of the autonomous forklift truck are counterbalanced by the weight of the frame or main body that supports the forks. As a result, the maximum weight of any load lifted by the autonomous pallet truck is very limited by the weight of the body of the autonomous pallet truck. As a result, the body of the autonomous pallet truck is intentionally made heavy to counterbalance any load lifted by the forks. The increased weight of the body of the autonomous pallet truck introduces other problems, including the need to provide sufficient power to drive the autonomous pallet truck across the floor, which in turn may require a larger motor to provide sufficient power to drive the autonomous pallet truck.

[0008] What is needed is a pallet moving device that does not suffer from the problems discussed above. Summary of the Invention

[0009] The present invention alleviates the above-mentioned problems by providing a pallet moving device in which wheels mounted on a plurality of forks are configured to step over one or more planks or runners in the lower deck of the pallet. This allows the plurality of forks to be inserted into the pallet without having to physically climb over or bump into one or more planks. To allow the plurality of forks of the pallet moving device to be inserted into the pallet, more specifically into the space between the upper and lower decks of the pallet, the plurality of forks include a first set of wheels and a second set of wheels, the first set of wheels being spaced apart from the second set of wheels such that the first set of wheels can be configured to step over one or more planks in the lower deck of the pallet.

[0010] More specifically, the present disclosure relates to a pallet moving device for moving a pallet, the pallet comprising a top deck formed from one or more planks and a bottom deck formed from one or more planks, the bottom deck being spaced apart from the top deck, the pallet moving device comprising: a body including a lift mechanism and a drive assembly for moving the pallet mover; a plurality of forks for lifting and handling pallets, wherein the plurality of forks extend outwardly from the body and are configured to be lifted by a lift mechanism; a first set of wheels and a second set of wheels, each of the first and second sets of wheels independently movable relative to the plurality of forks, the first set of wheels configured to be vertically movable, in use, between a stowed position in which it disengages from the floor and a deployed position in which it engages the floor, such that when the plurality of forks are inserted into the pallet, the first set of wheels clear one or more planks in the lower deck of the pallet; A pallet moving device is provided.

[0011] Another method of claiming the present disclosure is a pallet moving device, wherein a pallet comprises a top deck formed from one or more planks and a bottom deck formed from one or more planks, the bottom deck being spaced apart from the top deck, the pallet moving device comprising: a body including a lift mechanism and a drive assembly for moving the pallet mover; a plurality of forks for lifting and handling pallets, wherein the plurality of forks extend outwardly from the body and are configured to be lifted by a lift mechanism; a first set of wheels and a second set of wheels, wherein each of the first and second sets of wheels is configured to be independently movable relative to the plurality of forks; a control system operable to independently move the first set of wheels between a deployed position in engagement with the floor and a retracted position in disengagement from the floor, such that, in use, the first set of wheels clears one or more planks of the pallet when the plurality of forks are inserted into the pallet; The object of the present invention is to provide a pallet moving device comprising:

[0012] In a first aspect of the present disclosure, the plurality of forks include first and second sets of wheels configured to step over one or more planks in the lower deck of the pallet. To allow the first and second sets of wheels to step over one or more planks in the lower deck of the pallet, each of the first and second sets of wheels is configured to be independently movable vertically between a deployed position that engages the floor and a retracted position that disengages from the floor during use, such that either the first or second set of wheels contacts the floor at any time. The first set of wheels is spaced apart from the second set of wheels such that the first set of wheels is proximal to the distal end of the plurality of forks and the second set of wheels is proximal to the body of the pallet moving device. The second set of wheels functions as a balance wheel so that the first set of wheels is retracted. Optionally, the first and second sets of wheels are configured not to contact one or more planks of the pallet when stepping over them. Optionally, each wheel of the first and / or second sets of wheels is pivotally mounted to a plurality of forks to enable each set of the first and second sets of wheels to move independently in the vertical direction.

[0013] A first set of wheels proximal to the distal ends of the plurality of forks function as load-bearing wheels because they may be configured to withstand the weight of the pallet and any load supported by the pallet when the plurality of forks are raised. A second set of wheels spaced further from the distal ends of the plurality of forks may be configured to function as balance wheels to stabilize the pallet mover and prevent the pallet mover from tipping when the first set of wheels is retracted. To raise or lower the plurality of forks, optionally, the first or second set of wheels cooperate with a lift mechanism such that vertical movement of the first or second set of wheels raises or lowers the plurality of forks. Optionally, the lift mechanism is configured to lift the plurality of forks by vertically extending the first set of wheels relative to the plurality of forks when in the extended position. For example, the lift mechanism may include a hydraulic pump and / or an electric motor coupled to the first and / or second set of wheels by one or more levers to raise or lower the plurality of forks.

[0014] Each of the first and second sets of wheels does not need to be independently movable vertically to allow the forks to be inserted into the pallet. In a second aspect of the present disclosure, the second set of wheels is configured to engage the floor and be retractable longitudinally along the forks between a forward position and a storage or rearward position, the forward position being closer to the first set of wheels than the storage position. As in the first aspect of the present disclosure, the second set of wheels is configured as a balance wheel for stabilizing the pallet moving apparatus to prevent the pallet moving apparatus from tipping when the first set of wheels is in the storage configuration. To allow the forks to be fully inserted into the pallet when the first set of wheels is in the storage position, the second set of wheels is configured to be retractable longitudinally (in a substantially horizontal direction) along the forks between a forward position and a storage position, the forward position being closer to the first set of wheels than the storage position. For this purpose, the storage position may be referred to as a "rearward" position. The second set of wheels is retracted in a substantially horizontal direction relative to the forks when the forks are inserted into the pallet. The second set of wheels maintains stability of the pallet moving device as the forks are inserted into the pallet. Once fully inserted into the pallet, the first set of wheels can be deployed to an extended position to raise the forks. Optionally, the second set of wheels is biased to a forward position such that when the forks are inserted into the pallet, the second set of wheels is retracted by abutting against the lower deck of the pallet.

[0015] To configure the first and second sets of wheels to be independently movable relative to the multiple forks, optionally, the pallet moving apparatus further comprises an actuation mechanism operable to independently move the first set of wheels and / or the second set of wheels relative to the multiple forks. To actuate the actuation mechanism, the pallet moving apparatus further comprises a control system configured to operate the actuation mechanism to independently move the first set of wheels and / or the second set of wheels relative to the multiple forks. Preferably, the actuation mechanism may be configured to operate the lift mechanism to independently move the first and / or second sets of wheels in a vertical direction. Preferably, the pallet moving apparatus is an AGV. Preferably, the pallet moving apparatus is an autonomous pallet moving apparatus comprising a location awareness sensor for detecting a location of the pallet moving apparatus in a movement direction, and the control system is configured to move the pallet moving apparatus (defined herein as a pallet moving apparatus) in response to one or more signals from the location awareness sensor. Optionally, the location awareness sensor comprises a LiDAR sensor comprising a laser beam source, an optical receiver, and a scanning system for deflecting a laser beam generated by the laser beam source in at least two scanning directions.

[0016] To insert the forks of the pallet mover according to the first aspect of the present disclosure into a pallet, the control system is configured to retract the first or second set of wheels when the second or first set of wheels are in the extended position. Thus, when the first set of wheels is retracted, the second set of wheels remains in the extended position to balance the forks, and vice versa. This allows the first and / or second sets of wheels to step over one or more planks in the lower deck of the pallet. Similarly, to insert the forks of the pallet mover according to the second aspect of the present disclosure into a pallet, the control system is configured to vertically extend the first set of wheels when the first set of wheels is in the extended position to elevate the forks. Optionally, the control system is configured to retract the second set of wheels longitudinally along the forks to allow the forks to be inserted into the pallet. Preferably, the first set of wheels is proximal to the distal ends of the forks, and the second set of wheels is proximal to the body of the pallet mover. For example, in a first aspect of the present disclosure, when the second set of wheels is proximal to the body of the pallet mover and the first set of wheels is proximal to the distal ends of the multiple forks, retracting the first set of wheels while the second set of wheels remains in the deployed position allows the first set of wheels to step over one or more planks in the lower deck of the pallet. This process is followed by deploying the first set of wheels to balance the multiple forks when the second set of wheels is retracted, allowing the second set of wheels to step over one or more planks in the lower deck of the pallet. This allows both the first and second sets of wheels to step over one or more planks in the lower deck of the pallet when the multiple forks are inserted into the pallet.

[0017] In a second aspect of the present disclosure, when the forks are inserted into the pallet, the second set of wheels remain engaged with the floor to balance or stabilize the pallet moving device, while the first set of wheels remains in a retracted position. The first set of wheels is then deployed when the forks are fully inserted into the pallet. In either case, the first set of wheels bears the load of the pallet and any items installed on the pallet when the pallet is lifted, and the second set of wheels maintains the balance of the forks in a substantially horizontal orientation when the first set of wheels is retracted as it steps over one or more planks in the lower deck of the pallet. The second set of wheels can function as balance wheels when the first set of wheels is retracted.

[0018] Thus, to insert a plurality of forks into a pallet in accordance with the first aspect of the present disclosure, optionally a control system cooperating with the drive assembly includes: a) moving the pallet mover a first distance when the first set of wheels is retracted and the second set of wheels is deployed; d) moving the pallet moving device a second distance when the second set of wheels is retracted and the first set of wheels is deployed. The pallet mover is configured to move in a predetermined sequence of

[0019] The control system is configured to move the pallet mover a first distance when the first set of wheels is retracted and the second set of wheels is deployed to insert at least a portion of the plurality of forks into the pallet. The first set of wheels can then be deployed to engage the floor, and the second set of wheels can be retracted to allow the plurality of forks to be inserted the second distance into the pallet. The first and / or second distances can correspond to the width of one or more planks in the lower deck of the pallet. The first and / or second distances can be predetermined in a storage device, and the control system can be configured to execute instructions stored in the storage device to independently move the first and second sets of wheels in response to a separation between the first and second sets of wheels. A larger separation between the first and second sets of wheels reduces the number of operations required to independently retract and deploy the first and second wheel sets when stepping over one or more planks in the lower deck of the pallet compared to a smaller separation. Optionally, the first distance may be substantially equal to or different from the second distance to step over one or more planks in the lower deck of the pallet.

[0020] Optionally, the actuation mechanism comprises at least one linear actuator for deploying and retracting the first and second sets of wheels, the first and second sets of wheels being independently movable in their respective vertical directions by the at least one linear actuator.

[0021] The pallet moving device further comprises a proximity sensor for detecting the presence of an obstacle, for sensing the presence of one or more planks in the lower deck of the pallet and engaging the actuation mechanism to independently move the first and second sets of wheels in a vertical direction, the proximity sensor cooperating with the actuation mechanism such that, in use, the actuation mechanism is configured to actuate the vertical movement of the first or second sets of wheels in response to a signal from the proximity sensor. Examples of proximity sensors include, but are not limited to, LiDAR, or even a vision system comprising one or more cameras for visualizing the presence of an obstacle. Optionally, the proximity sensor is disposed at a distal end of at least one of the plurality of forks relative to the body.

[0022] For moving the pallet mover, preferably the drive assembly comprises a drive wheel rotatable about a drive axis and a drive mechanism for driving the drive wheel about the drive axis. For maneuvering the pallet mover within a warehouse, preferably the pallet mover further comprises a steering mechanism for changing the direction of the pallet mover. Optionally, the steering mechanism is coupled to the drive wheel and configured to rotate the drive wheel about a steering axis that is substantially perpendicular to the drive axis of the drive wheel.

[0023] While the maneuverability of the pallet moving device can be controlled autonomously, there are times when the movement of the pallet moving device needs to be manually driven by an operator. Examples of when the autonomous control of the pallet moving device needs to be manually overridden include, but are not limited to, when the pallet moving device attempts to maneuver around a tight corner or an obstacle, when attempting to release the pallet moving device, or simply when manually controlling the maneuverability of the pallet moving device. To manually override the movement of the pallet moving device when in autonomous mode, the pallet moving device further includes a user manual interface configured to manually override the autonomous control of the pallet moving device in order to move the pallet moving device, the user manual interface having an interface portion configured to couple with the steering mechanism and drive assembly such that the user manual interface controls the direction and movement of the pallet moving device. Optionally, the interface portion is electrically coupled to the steering mechanism and drive assembly. For example, when the control system detects that the user manual interface is coupled to the main body of the pallet moving device, the control system can switch the pallet moving device from autonomous mode to manual mode. When in manual operation mode, the user manual interface can be manually operated to control the steering mechanism and drive assembly of the pallet moving device.

[0024] To eliminate the burden of supporting the extra weight of the user manual interface when in autonomous mode and / or to switch to another pallet moving apparatus, the user manual interface is optionally detachable from the body of the pallet moving apparatus. For example, the user manual interface may be decoupled from the body of the pallet moving apparatus when in autonomous mode. To enable the user manual interface to be detached from the body of the pallet moving apparatus, optionally the user manual interface comprises a body and a wheel assembly for moving the body. Optionally, the user manual device comprises a manual steering mechanism coupled to the wheel assembly for steering the body of the user manual device. To enable the user manual interface to be driven independently of the pallet moving apparatus, optionally the user manual device comprises an independent drive mechanism coupled to the wheel assembly. This allows the user manual device to be detached from the pallet moving apparatus and coupled to another pallet moving apparatus to control its movement.

[0025] Optionally, the pallet mover further comprises a coupling sensor for switching the pallet mover between an autonomous mode of operation and a manual mode of operation in response to one or more signals from the coupling sensor, for example, the user manual interface and / or the body of the pallet mover comprises a coupling sensor configured to switch operation of the pallet mover between the autonomous mode and the manual mode via the control system in response to one or more signals from the coupling sensor.

[0026] Optionally, the manual steering mechanism comprises a tiller arm or a steering wheel. Optionally, the tiller arm is movable along an arc between a substantially horizontal position and a substantially vertical position. For example, the tiller is rotatable left and right to steer the pallet moving apparatus. The present disclosure further provides a method of moving / handling a pallet by a pallet moving apparatus according to a first aspect of the present disclosure, comprising the step of independently moving first and second sets of wheels vertically so as to clear one or more planks in a lower deck of the pallet when the multiple forks are inserted into the pallet.

[0027] Preferably, the first and second sets of wheels comprise: a) retracting the first set of wheels to disengage the first set of wheels from the floor; b) moving the pallet moving device toward the pallet such that at least a portion of the plurality of forks enter the pallet; c) deploying the first set of wheels to engage the first set of wheels with the floor; d) retracting the second set of wheels to disengage the second set of wheels from the floor; e) moving the pallet moving device toward the pallet so that an increased portion of the plurality of forks enters the pallet than in step (b); step over one or more planks in the lower deck of the pallet.

[0028] The present disclosure provides: a) moving a pallet mover a first distance toward a pallet such that first portions of a plurality of forks enter the pallet; b) storing a second set of wheels longitudinally along the plurality of forks relative to the plurality of forks; c) moving the pallet mover a second distance toward the pallet such that a second portion of the plurality of forks enters the pallet; There is further provided a method for moving / handling pallets by a pallet moving apparatus according to the second aspect of the present disclosure.

[0029] Once inserted into the pallet, the method further comprises elevating the plurality of forks by extending the first set of wheels in a substantially vertical direction.

[0030] Thus, instead of moving the first and second sets of wheels of the pallet mover in a substantially vertical direction to clear one or more planks in the lower deck of the pallet, the first set of wheels proximal to the distal or free ends of the plurality of forks remains in a retracted position to allow the plurality of forks to be inserted a first distance into the pallet (i.e., between the upper and lower decks of the pallet). The second set of wheels remains engaged with the floor to stabilize the pallet mover as the plurality of forks are inserted into the pallet. The second set of wheels retracts longitudinally along the plurality of forks when the plurality of forks are inserted a further second distance into the pallet. The second distance allows the plurality of forks to be fully inserted into the pallet. Preferably, the method further comprises the step of elevating the plurality of forks by extending the first set of wheels in a substantially vertical direction.

[0031] Further features and aspects of the present disclosure will become apparent from the following detailed description of illustrative examples which proceeds with reference to the drawings. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a schematic diagram of a pallet moving device according to a first example of the present disclosure approaching a pallet. FIG. [Figure 2a] 2 is a schematic diagram of the pallet mover shown in FIG. 1 engaging a pallet, where a first set of wheels is retracted and a second set of wheels is deployed. [Figure 2b]2 is a schematic diagram of the pallet moving device shown in FIG. 1 engaging a pallet, wherein at least a portion of the multiple forks are inserted into an opening in the pallet so as to step over a first plank in the lower deck of the pallet. [Figure 2c] FIG. 2 is a schematic diagram of the pallet moving device shown in FIG. 1 engaging a pallet, where a first set of wheels is deployed and a second set of wheels is retracted to allow the multiple forks to be inserted further into the pallet. [Figure 2d] FIG. 2 is a schematic diagram of the pallet moving device shown in FIG. 1 engaging a pallet, where the forks are further inserted into the pallet to step over a first plank in the lower deck of the pallet. [Figure 2e] FIG. 2 is a schematic diagram of the pallet moving device shown in FIG. 1 engaging a pallet, where a first set of wheels is retracted to allow the multiple forks to step over a second plank in the lower deck of the pallet. [Figure 2f] FIG. 2 is a schematic diagram of the pallet mover shown in FIG. 1 engaging a pallet, where a first set of wheels is deployed and a second set of wheels is retracted to complete the operation of the pallet mover engaging the pallet. [Figure 2g] 2 is a schematic diagram of the pallet moving device shown in FIG. 1 engaging a pallet, where multiple forks rise to lift the pallet. [Figure 3] FIG. 10 is a schematic diagram of a pallet mover according to a second example of the present disclosure approaching a pallet. [Figure 4a] FIG. 4 is a schematic diagram of the pallet mover shown in FIG. 3 engaging a pallet, where the first set of wheels is retracted and the second set of wheels is deployed. [Figure 4b] FIG. 4 is a schematic diagram of the pallet moving device shown in FIG. 3 engaging a pallet, where a first set of wheels is deployed and a second set of wheels is retracted to allow the multiple forks to be inserted further into the pallet. [Figure 4c]FIG. 4 is a schematic diagram of the pallet mover shown in FIG. 3 engaging a pallet, where a first set of wheels is deployed and a second set of wheels is retracted to complete the operation of the pallet mover engaging the pallet. [Figure 5] FIG. 1 is a block diagram showing the main components of a pallet mover for engaging a pallet. [Figure 6] FIG. 10 is a flow diagram illustrating example steps taken when a pallet mover engages a pallet. [Figure 7(a)-(e)] 10 is a schematic diagram illustrating the steps performed by a pallet mover according to a second example of the present disclosure when engaging a pallet. [Figure 8] FIG. 10 is a perspective view of a pallet mover incorporating a user manual interface according to a third example of the present disclosure. [Figure 9] FIG. 10 is a perspective view of a pallet mover with a removable user manual interface according to a third example of the present disclosure. [Figure 10] FIG. 10 is a perspective view of a warehouse receiving area showing the unloading of pallets from a trailer using a pallet moving apparatus according to a third example of the present disclosure. [Figure 11] FIG. 10 is a perspective view of a pallet mover with an integrated user manual interface, showing the pallet mover in a manual mode of operation, according to a third example of the present disclosure. [Figure 12] FIG. 12 is a perspective view of the pallet mover shown in FIG. 11, showing the pallet mover in an autonomous mode of operation. [Figure 13] 10 is another example of a perspective view of a pallet mover with a removable user manual interface according to a third example of the present disclosure. [Figure 14] FIG. 14 is a perspective view of a warehouse receiving area showing the unloading of pallets from a trailer using the pallet mover shown in FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0033] With the trend toward automation and unmanned production systems within warehouses or distribution centers, the present disclosure provides a pallet mover that improves the flexibility with which the forks of the pallet mover can engage with pallets. With the movement toward using autonomous guided vehicles (AGVs) to transport items within warehouses, there is an increasing need for AGVs to have the ability to autonomously create precise and safe work capabilities in any work environment. In various forms of examples of the present disclosure, the pallet mover can be or take the form of an automated guided vehicle (AGV), such as, for example, a vision-guided vehicle. In some examples of the present disclosure, the pallet mover can be an AGV / VGV pallet mover configured with object sensing technology known in the art.

[0034] One of the complications of making a pallet mover autonomous (referred to herein as an "autonomous pallet mover or robotic pallet mover") is the ability of the forks of the pallet mover to insert into the space between the top and bottom decks of the pallet to engage the pallet. Traditionally, with a manual pallet mover, engaging the pallet would require the forks to be forced into the space between the top and bottom decks of the pallet so that the wheels stabilizing the pallet mover can enter the space. In the case of open or full-perimeter pallets, which may have two-way or four-way entry to the pallet, the bottom deck of the pallet has at least planks or runners thereon (see FIG. 1) to improve the rigidity of the pallet. To engage the pallet, the wheels proximal to the distal ends of the forks must physically climb over or bump against one or more of the planks in the bottom deck of the pallet. When making the pallet mover autonomous, a complication arises because the pallet mover needs to measure the number and / or thickness of each of the planks in the lower deck of the pallet to determine the force required to allow the stabilizing wheels proximal to the distal ends of the forks to physically overcome the planks in the lower deck of the pallet.

[0035] According to the present disclosure, the multiple forks of the pallet moving device include first and second sets of wheels, each configured to move independently vertically relative to the multiple forks between a deployed position that engages the floor and a retracted position that disengages from the floor. The first and second sets of wheels are spaced apart to allow the first and second sets of wheels to clear one or more planks in the lower deck of the pallet. To clear one or more planks in the lower deck of the pallet, the spacing between the first and second sets of wheels corresponds to or is greater than the width of one or more planks in the lower deck of the pallet to allow the first and second sets of wheels to clear the one or more planks when engaging the pallet. The spacing between the first and second sets of wheels may be defined as the distance S between the centers of the wheels of the first set of wheels and the centers of the wheels of the second set of wheels (see FIG. 1 ).

[0036] The first set of wheels proximal to the distal ends of the forks function as load-bearing wheels because they bear the weight of the pallet and any load supported by the pallet when the forks are raised. The second set of wheels, spaced further from the distal ends of the forks, function as balance wheels to stabilize the pallet mover against tipping when the first set of wheels is retracted. Similarly, the first set of wheels stabilize the pallet mover against tipping when the second set of wheels is retracted. Thus, each of the first and second sets of wheels independently deploys and retracts when stepping over one or more planks in the lower deck of the pallet. The first and second sets of wheels may be defined as the front and rear sets of wheels, respectively.

[0037] An example of a pallet moving apparatus 1 according to the present disclosure is shown in FIG. 1 and includes a body 2 including a drive assembly (not shown) for moving the pallet moving apparatus across a floor, a steering mechanism (not shown) for steering the pallet moving apparatus 1, and a lift mechanism (not shown) for raising and lowering a plurality of forks 4 extending from the body 2. In the particular example of the present disclosure shown in FIG. 1, the pallet moving apparatus 1 includes two forks defining a left fork 6 and a right fork 8. A first set of wheels 10 and a second set of wheels 12 are mounted to the left fork 6 and the right fork 8, in the sense that half of the wheels of the first set of wheels 10 and the second set of wheels 12 are mounted to the left fork 6, and the other half of the wheels of the first set of wheels 10 and the second set of wheels 12 are mounted to the right fork 8. For ease of explanation of the present disclosure, each of the first and second sets of wheels 10, 12 includes a first wheel 14 and a second wheel 16. A first wheel 14 and a second wheel 16 of each of the first and second sets of wheels 10 , 12 are shown mounted to respective left and right forks 6 , 8 of the pallet moving device 1 .

[0038] Although the first and second sets of wheels 10, 12 are shown rotatably mounted inside the forks 4, other means for rotatably mounting the first and second sets of wheels 10, 12 to the forks 4 to allow the forks 4 to move across a floor are acceptable within the present disclosure. The number of forks is not limited to two and can include any number of forks, for example, a pallet moving device having three forks. Each wheel of the first and second sets of wheels 10, 12 can be pivotally mounted to the forks 4 to allow vertical movement. For example, each wheel of the first and second sets of wheels 10, 12 can be mounted to a lever (not shown) pivotally mounted to the forks 4 that retracts vertically to retract each wheel toward the inside of its respective fork, thereby disengaging from the floor, and extends outward from its respective fork to engage the floor in the deployed position. However, other means for mounting each set of wheels of the first and second sets 10, 12 to allow vertical movement relative to the forks 4 are acceptable within the present disclosure. An actuation mechanism (not shown) coupled to the first and second sets of wheels 10, 12 is configured to move each of the first and second sets of wheels independently in a vertical direction, further details of the actuation mechanism are discussed below.

[0039] A lift mechanism (not shown) is connected to the multiple forks for raising and lowering the multiple forks. Various lift mechanisms commonly known in the art can be used to raise and lower the multiple forks. These include, but are not limited to, hydraulic pumps, electric motors, etc. Typically, the multiple forks are connected to a frame forming the body of the pallet mover, and a lift mechanism is connected to the multiple forks and the frame such that the lift mechanism is configured to raise and lower the frame and the multiple forks. The lift mechanism can cooperate with the first or second set of wheels to raise or lower the multiple forks. For example, the multiple forks can be raised by lowering the first or second set of wheels. The first set of wheels can be mounted on a lever attached to a linkage that leads to a lever attached to a hydraulic pump in the body of the pallet mover that lowers the first or second set of wheels to raise the multiple forks. Because the first set of wheels can be primarily load-bearing wheels, the first set of wheels can be lowered to raise the multiple forks. The lower the first set of wheels relative to the multiple forks, the higher the multiple forks can be raised. Alternatively, the lift mechanism for raising the forks may be separate from the first and second sets of wheels, but the first or second sets of wheels lower as the forks are raised. The locking mechanism locks the first or second sets of wheels in a lowered position when the forks are in the raised position so as to raise a pallet engaged with the forks from the ground.

[0040] A drive assembly (not shown) including one or more drive wheels propels the pallet truck across the floor. In the case of a powered pallet mover, the drive assembly includes a drive mechanism, e.g., a drive motor, for driving the rotation of the one or more drive wheels about a drive axis. The drive assembly is located at the rear of the pallet mover within the body. The drive wheels for propelling the pallet mover across the floor may be connected to a steering mechanism (not shown) for steering the pallet mover across the floor. The steering mechanism may be configured to rotate one or more of the drive wheels around a steering axis substantially perpendicular to the drive axis to change the direction of the pallet mover across the floor. Various steering mechanisms known in the art may be used to change the direction of the pallet mover. These include, but are not limited to, a steering drive unit coupled to one or more drive wheels configured to rotate one or more of the drive wheels around a steering axis. For example, the body of the pallet mover may include swivel casters located at the four corners of the body of the pallet mover. The drive wheels and steering wheels propel and change the direction of the body of the pallet mover, respectively. The steering mechanism may be separate from the drive assembly in the sense that a separate steering wheel may be used to change the direction of the pallet mover independent of the propulsion of the pallet mover by the drive assembly.

[0041] In the case of an AGV (Automated Guided Vehicle), the pallet mover may include a guidance system (not shown) coupled to the drive assembly and steering mechanism to control movement of the pallet mover on the work site. The guidance system may include, but is not limited to, wire guidance, laser guidance, magnetic tape guidance, odometry guidance, inertial guidance, or optional guidance. For example, a laser guidance system uses special markers that the AGV pallet mover senses and uses to control its movement. The guidance system is controlled by a control system including a controller, such as a processor, and a memory storage device for storing instructions executed by the controller to control the operation of the pallet mover. The control system may be a central controller separate from the AGV and communicate with the AGV via wireless means, or alternatively, the control system may be internal to the AGV receiving instructions stored in the memory storage device. The memory storage device may be any storage device commonly known in the art, including, but not limited to, RAM, computer-readable media, magnetic storage media, optical storage media, or other electronic storage media used to store data and accessible by the controller. Controlling the operation of the pallet moving apparatus includes, but is not limited to, controlling a drive assembly and steering mechanism in response to signals from a guidance system to control movement of the pallet moving apparatus, controlling vertical movement of first and second sets of wheels mounted on the plurality of forks to engage the pallet, and controlling a lift mechanism to raise and lower the pallet. The pallet moving apparatus may further comprise a battery (or some other power source) for powering the different components discussed above. The pallet moving apparatus may comprise an interface by which the battery can be recharged or by which the battery can be hot-swapped to allow continued pallet moving apparatus operation. The pallet moving apparatus may further comprise a wireless interface by which it can receive data from a central controller and send data, e.g., status messages, data logs, etc., back to the central controller.

[0042] While known systems can be used in this disclosure to control the movement of the pallet moving apparatus, this disclosure focuses more on the engagement of the plurality of forks 4 with the pallet 18. To engage the plurality of forks 4 with the pallet 18, a control system, cooperating with the actuation mechanism and drive mechanism, is configured to move the pallet moving apparatus to fully engage the pallet. The term "fully" engage the plurality of forks with the pallet is used to describe a condition in which the plurality of forks are inserted into the pallet so that the pallet can be lifted off the floor. The actuation mechanism can include linear actuators for vertically moving each of the first and second sets of wheels via one or more linkages. The control system can be configured to operate the actuation mechanism to independently move the first and second sets of wheels vertically. For example, the actuation mechanism can include a first linear actuator for raising and lowering the first set of wheels and a second linear actuator for raising and lowering the second set of wheels. To independently move the first set of wheels and the second set of wheels vertically, the control system may be configured to independently actuate a first linear actuator to deploy or retract the first set of wheels and a second linear actuator to deploy or retract the second set of wheels. Alternatively, or in combination with the linear actuators, the actuation mechanism may include a cam mechanism including one or more cams and a cam follower movable along the one or more cams to move the cam follower from a raised position to retract the first and / or second sets of wheels and a lowered position to deploy the first and / or second sets of wheels.

[0043] 2(a-g) are schematic diagrams illustrating the stages of engagement of the forks 4 with a pallet 18. The engagement operation involves independently retracting and deploying the first and second sets of wheels 10, 12 in a predetermined sequence in conjunction with driving the pallet mover 1 toward the pallet 18. This operation begins with retracting the first set of wheels 10 (i.e., the front set of wheels) proximal to the distal ends of the forks 4 to allow the fronts of the forks 4 to be inserted into openings provided by the space between the upper deck 20 and lower deck 22 of the pallet 18. In FIG. 2b, the pallet mover 1 moves a first distance L1 toward the pallet 18 so that the fronts of the forks 4 clear planks or runners 24 in the lower deck 22 of the pallet 18. The first distance depends on the spacing between the first set of wheels 10 and the second set of wheels 12. In a specific example of the present disclosure, the first distance L1 is sufficient for the second set of wheels 12 proximal to the body 2 of the pallet mover 1 to step over a single plank 24 in the lower deck 22 of the pallet 18 without physically climbing over or bumping over the single plank, as shown in FIG. 2b. The first distance L1 may be a predetermined distance applicable to the type of pallet stored in a memory storage device and may depend on the width of the one or more planks 24 in the lower deck 22 of the pallet 18. Once the pallet mover 1 has moved the first distance L1 toward the pallet 18 so that the front ends of the multiple forks 4 enter the pallet 18, the engagement operation proceeds to deploy the first set of wheels 10 to engage the floor and then retract the second set of wheels 12, as shown in FIG. 2c. Deploying the first set of wheels 10 before retracting the second set of wheels 12 maintains the stability of the pallet mover 1 and prevents the pallet mover 1 from tipping when the second set of wheels 12 is retracted. This allows the pallet mover 1 to move a second distance L2 towards the pallet 18 to further insert the forks 4 into the pallet 18, as shown in Figure 2d. Like the first distance, the second distance may be a predetermined distance applicable to the type of pallet stored in the memory storage device.The predetermined sequence of operations—(i) retracting the first set of wheels, (ii) moving the pallet mover a first distance toward the pallet, (iii) deploying the first set of wheels and retracting the second set of wheels, and (iv) moving the pallet mover a second distance toward the pallet—is repeated when the second plank in the lower deck of the pallet is cleared, as shown in FIGS. 2e and 2f. Because there are typically three planks or runners 24 in the lower deck of the pallet, once the first and second sets of wheels clear the first and second planks, the forks are considered fully engaged with the pallet, as shown in FIG. 2f. Once the forks are fully engaged with the pallet, the next operation would be to lift the pallet 18 off the floor, as shown in FIG. 2g, so that the pallet 18 can be moved across the floor. Lifting the pallet 18 involves lowering or deploying the first set of wheels 10 relative to the forks by the actuation mechanism, such that the forks 4 are raised. Alternatively, the forks are separately raised and lower the first set of wheels 10 to engage the floor. A locking mechanism (not shown) locks the first set of wheels in a lowered or extended position to lift the pallet engaged with the forks from the floor.

[0044] The first set of wheels 10 proximal to the distal ends of the plurality of forks 4 are load-bearing wheels because they bear the weight of the pallet 18 and any load placed on the pallet when it is lifted off the ground. The second set of wheels 12 proximal to the body 2 of the pallet moving device 1 act as balance wheels to prevent the pallet moving device 1 from tipping when the first set of wheels 10 is retracted. This allows the first and second sets of wheels 10, 12 to clear one or more planks 24 in the lower deck 22 of the pallet 18, as shown in FIGS. 2(a-g). The spacing between the first set of wheels 10 and the second set of wheels 12 depends on the number of planks 24 in the lower deck of the pallet 18 and the number of movements required for the first and second sets of wheels 10, 12 to clear one or more planks 24 in the lower deck of the pallet when fully engaging the pallet.

[0045] In the second example of the present disclosure shown in Figure 3, the spacing S between the first set of wheels 110 and the second set of wheels 112 is such that the multiple forks 104 fully engage with the pallet 18 in fewer movements than in the first example shown in Figure 1. Compared to the first example of the present disclosure shown in Figures 2(a-g), which requires multiple movements of the first and second sets of wheels 10, 12 to fully engage with the pallet 18, in the second example of the present disclosure shown in Figure 3, a single movement is required for the pallet moving device 101 to move toward the pallet 18 a first distance L1 corresponding to the distance the first set of wheels 110 clears two planks 24 in the lower deck 22 of the pallet 18, i.e., the first distance L1 corresponds to the spacing between the two planks 24 in the lower deck of the pallet including the width of the two planks. 4(a-c) begins with retracting the first set of wheels 110 so that they clear a first plank on the periphery of the pallet 18 and inserting the forks into the pallet. Because the spacing between the first set of wheels and the second set of wheels is large enough to clear or step over two spaced apart planks in the lower deck of the pallet, the forks 104 can be further inserted into the pallet to step over two planks in the lower deck of the pallet in a single moving motion.

[0046] To fully engage the pallet 18, the first set of wheels 110 are deployed, as shown in FIG. 4b, and the second set of wheels 112 are retracted, allowing the pallet mover to move closer a second distance L2 toward the pallet 18, as shown in FIG. 4c. Once the forks are fully engaged with the pallet, the forks 104 may be raised to lift the pallet off the floor. Raising the forks can be accompanied by lowering or deploying the first set of wheels 110. Alternatively, the forks are independently raised and lowered to engage the first set of wheels 110. A locking mechanism (not shown) locks the first set of wheels in the lowered position to lift the pallet engaged with the forks off the floor.

[0047] The spacing S between the first set of wheels and the second set of wheels can be changed by changing the position of the first set of wheels 10, 110 relative to the second set of wheels 12, 112. The closer the second set of wheels 12, 112 can be to the body 2, 102 of the pallet mover 1, 101 without tilting the pallet mover when the first set of wheels 10, 110 is retracted, the greater the spacing between the first set of wheels and the second set of wheels. Typically, the spacing S between the first set of wheels and the second set of wheels must be greater than 100 cm in order for the first set of wheels 110 to step over two planks in the lower deck of the pallet in a single movement.

[0048] To automate the independent movement of the first and second sets of wheels when engaging a pallet as shown in FIGS. 1 and 3 , the pallet mover 1, 101 includes one or more proximity sensors for detecting the presence of a nearby obstacle or object, in this case, one or more planks in the lower deck of the pallet. Examples of proximity sensors for detecting the presence of an object include, but are not limited to, a LiDAR sensor with a laser beam source and an optical receiver, and an ultrasonic sensor. Another example of detecting the presence of a nearby object is the use of one or more cameras or depth cameras to visualize the presence of a nearby object or obstacle. The proximity sensor or camera may be mounted on the forks, particularly on the distal end of one or more of the forks. Alternatively, the proximity sensor or camera may be mounted on the body of the pallet mover. A control system is coupled to the proximity sensor and / or camera and configured to independently retract or deploy the first and second sets of wheels in response to one or more signals from the proximity sensor and / or camera.

[0049] FIG. 5 is a simplified block diagram 30 illustrating the major components of a pallet moving apparatus for engaging a pallet, and FIG. 6 is a flow diagram 50 illustrating example steps performed by the pallet moving apparatus when engaging a pallet. The major components of the pallet moving apparatus for engaging a pallet may be summarized in FIG. 5 to include an actuation mechanism 38 configured to vertically move the first and second sets of wheels, a proximity sensor 44 for sensing nearby objects, a drive assembly 40 for steering the pallet moving apparatus, and a forklift mechanism 42 for raising and lowering the plurality of forks. Each of the components for engaging a pallet is controlled by a control system 32 including a controller 34, e.g., a processor, and a memory storage device 36 for storing instructions to be executed by the controller 34. For example, the instructions include actuating the actuation mechanism 38 to independently move the first and second sets of wheels vertically in response to one or more signals from the proximity sensor 44. The steps in engaging the plurality of forks with a pallet may be summarized in a flow chart 50 shown in FIG. 6 in conjunction with FIG. 5. The process begins with the proximity sensor detecting 54 the presence of a plank in the lower deck of the pallet 52. In response to detecting the presence of the plank, the controller 34 actuates the actuation mechanism 38 to retract a first set of wheels and deploy a second set of wheels 56. This allows the pallet mover to move a first distance toward the pallet as the first set of wheels clear the plank 58. However, if the pallet mover does not detect the presence of the pallet, the pallet mover is commanded 66 to continue moving until the pallet is detected. To fully engage the pallet, the controller 34 actuates the actuation mechanism 38 to deploy the first set of wheels and retract the second set of wheels, allowing the second set of wheels to clear the plank as the pallet mover moves a second distance 62 toward the pallet.

[0050] Depending on the spacing between the first set of wheels and the second set of wheels, the next step would be to determine whether the forks have fully engaged with the pallet 64. If the spacing between the first set of wheels and the second set of wheels is relatively small (see FIG. 1), the first and second sets of wheels may need to step over two planks in two sets of movements or steps (e.g., four movements) to fully engage the pallet. After stepping over the first plank of the pallet, the controller 34, responsive to one or more signals from the proximity sensor 44, is configured to actuate the actuation mechanism 38 to independently move the first and second sets of wheels to step over a second plank in the lower deck of the pallet. One set of movements or steps for stepping over one or more planks in the lower deck of the pallet may involve: i) retracting a first set of wheels and deploying a second set of wheels; ii) moving the pallet moving device a first distance to insert a portion of the plurality of forks into the pallet and overstep a first plank in the lower deck of the pallet; iii) deploying a first set of wheels and retracting a second set of wheels to stabilize the plurality of forks; iv) moving the pallet moving device a second distance to insert an increased portion of the plurality of forks into the pallet;

[0051] Because the spacing between the first set of wheels and the second set of wheels is relatively small, the above operations (i) through (iv) are repeated to clear the second plank in the lower deck of the pallet. As shown in FIG. 3 , when the spacing between the first set of wheels and the second set of wheels is relatively large, the forks fully engage with the pallet after clearing two planks in the lower deck of the pallet in one set of operations (i) through (iv), i.e., the movement of the forks along the first and second distances. When approaching the pallet 52, the first and second sets of wheels may already be deployed, in which case step (i) may involve storing the first set of wheels when the second set of wheels is already deployed to clear the plank in the lower deck of the pallet. Data related to the type of the forks, including the spacing between the first and second sets of wheels, is stored in the memory storage device 36. A controller in cooperation with the memory storage device is capable of determining the type of the forks when engaging the pallet.

[0052] The frequency with which the first and second sets of wheels must step over one or more planks in the lower deck of the pallet in order for the plurality of forks to fully engage the pallet will depend on the separation S between the first set of wheels and the second set of wheels along the plurality of forks. The closer the separation S between the first set of wheels and the second set of wheels, the more times the first and second sets of wheels will need to step over one or more planks in the lower deck of the pallet. In the second example of a pallet moving device 201 shown in Figures 7(a-e), the second set of wheels 212 may be configured to be retractable longitudinally along the plurality of forks 204 to vary the separation between the first set of wheels 210 and the second set of wheels 212, rather than substantially vertically as in the first example of the present disclosure discussed above with reference to Figures 1-6. As shown in FIG. 7( a), the second set of wheels 212 moves along axis XX, eliminating the need for a predetermined separation between the first set of wheels and the second set of wheels, and therefore eliminating the need for the second set of wheels 212 to step over one or more planks in the lower deck 22 of the pallet 18.

[0053] To ensure stability of the pallet mover 201 when the first set of wheels 210 is retracted, the second set of wheels 212 remains engaged with the floor but retracts longitudinally along the plurality of forks 204 as the second set of wheels 212 approaches the lower deck 22 of the pallet 18. When inserted into the pallet 18, a lift mechanism (not shown) is configured to vertically extend or deploy the first set of wheels 210 relative to the plurality of forks 204 to engage the floor. Further extension of the first set of wheels 210 relative to the plurality of forks 204 elevates the plurality of forks 204 and the pallet supported by the plurality of forks. In the particular example shown in FIG. 7(e), the second set of wheels 212 separates from the plurality of forks to maintain stability of the body of the pallet mover 201 when the plurality of forks 204 are raised. As shown in FIGS. 7(a-e), the second set of wheels 212 is mounted on a plurality of runners 216 that allow the second set of wheels to be retracted longitudinally parallel to the plurality of forks. The runners 216 are mounted to the body 202 of the pallet mover such that when the forks are raised, the second set of wheels 212 separates from the forks, as shown in FIG. 7(e).

[0054] Similar to the first example of the present disclosure, the first and second sets of wheels 210, 212 may be independently movable relative to the plurality of forks 204. The independent movement of the first and second sets of wheels may be controlled by an actuation mechanism, as discussed above. As the second set of wheels 212 approaches the lower deck 22 of the pallet 18, longitudinal movement of the second set of wheels occurs from a forward position, as shown in FIG. 7(b), to a rearward position, as shown in FIG. 7(d). Various means may be used to move the second set of wheels 212 longitudinally (in a substantially horizontal direction) along the plurality of forks 204. In one example, the second set of wheels 212 may be resiliently biased forward by a resilient member (e.g., a spring) so that the second set of wheels 212 is closer to the first set of wheels 210 in the rest position, providing increased stability of the pallet moving device 201 when the first set of wheels is in a vertically stored configuration within the plurality of forks 204. The resilient member (not shown) is configured to longitudinally retract the second set of wheels 212 away from the first set of wheels when the bias of the resilient member is overcome. For example, the resilience of the resilient member can be selected such that the bias of the resilient member is overcome by a drive assembly (e.g., a motor) of the pallet mover. The second set of wheels 212 is positioned to abut against the lower deck 22 of the pallet 18 when the forks 204 are initially inserted into the pallet (see FIG. 7c). This bias is overcome by the drive assembly moving the pallet 18 and engaging the forks with the pallet. In the particular example shown in FIGS. 7(a-e), the drive assembly includes a drive wheel 214 rotatable about a drive shaft for driving movement of the pallet mover across the floor. The mere driving action of the pallet mover toward the pallet can be sufficient to overcome the bias of the second set of wheels and retract away from the first set of wheels as the forks progressively engage the pallet (see FIG. 7d).

[0055] Instead of the second set of wheels abutting the lower deck of the pallet, each wheel of the second set of wheels may be mounted on a cradle that is longitudinally movable along its respective fork and positioned to abut the lower deck as the forks enter the pallet. The use of a cradle to support each of the second set of wheels mitigates the risk of the second set of wheels climbing over one or more of the planks in the lower deck of the pallet as the forks enter the pallet. Alternatively, a drive mechanism responsive to signals from a suitable sensor (e.g., a proximity sensor) may be configured to progressively retract the second set of wheels as the forks progressively engage the pallet. In all cases, the first set of wheels remains retracted until the forks are fully engaged with the pallet.

[0056] The steps of engagement between the multiple forks of a pallet moving apparatus 201 and a pallet 18 according to a second example of the present disclosure may now be described with reference to FIGS. 7(a)-7(e). The positions of the first set of wheels 210 and the second set of wheels 212 relative to the multiple forks 204 in a normal configuration are shown in FIG. 7(a), which shows the first set of wheels 210 in a retracted position and the second set of wheels 212 in a forward position relative to the multiple forks to maintain stability of the pallet moving apparatus as it moves across the floor. The second set of wheels 212 is shown mounted on a cradle that is movable in the longitudinal or axial direction X. Also shown is a drive wheel 214 mounted on the body 202 of the pallet moving apparatus 201 for moving the pallet moving apparatus. The second set of wheels 212 approaches the lower deck 22 of the pallet 18 when the multiple forks 204 enter the pallet as shown in FIG. 7(b). Further movement of the pallet mover 201 toward the pallet not only increases the percentage of the forks entering the pallet, but also forces the second set of wheels 212 against the lower deck 22 of the pallet 18, more specifically, against a plank in the lower deck of the pallet, as shown in FIG. 7(c). This causes the second set of wheels 212 to retract rearward away from the first set of wheels 210 as the forks are driven into the pallet, as shown in FIG. 7(d). Once the forks are fully engaged with the pallet, as shown in FIG. 7(e), the lift mechanism is activated, extending the first set of wheels 210 vertically to engage the floor, stabilizing the pallet mover on the floor as the forks are raised. Further extension or lowering of the first set of wheels raises the forks, which in turn raises the pallet off the floor. As with the first example of the pallet mover, the lift mechanism can include a hydraulic pump and / or an electric motor coupled to the first set of wheels by one or more levers to raise or lower the forks.

[0057] While the move toward autonomously controlling the movement of pallet movers has increased the efficiency of moving pallets throughout a warehouse, there are still instances where manual intervention is required to move the pallet mover. Simply put, there may be instances where the control system that autonomously controls the movement of the pallet mover needs to be manually overridden in order to control the movement of the pallet mover. Instances where the control of the pallet mover needs to be manually overridden include, but are not limited to, getting around tight corners or obstacles, freeing a stuck pallet mover, or simply efficiently utilizing floor space within a warehouse when 100% autonomous control does not provide an effective way to move pallets throughout the warehouse. Typically, AGV pallet movers may require specialized surfaces or flooring, including built-in sensors or markings on the floor, to navigate around and through obstacles. However, such specialized surfaces are not always present, for example, in the receiving area of ​​a warehouse where stock or goods arriving on pallets on the back of a trailer or truck need to be transported into the warehouse and then transported to their final destination. Typically, such trailers are tightly spaced areas that require the pallet moving device to maneuver through tight spaces in order to properly engage the multiple forks with the pallets in the trailer. Second, the trailer may not have the appropriate markings or sensors to autonomously control the movement of the pallet moving device, i.e., the pallet moving device may lose signals carrying instructions from a central controller to autonomously control the movement of the pallet moving device.

[0058] To overcome this problem, the pallet moving apparatus 301 according to the present disclosure may be semi-autonomous, having an autonomous mode and a manual mode. In the autonomous mode, the control system 32 receives signals with instructions to control the movement of the pallet moving apparatus 301 within the warehouse. In the example shown in FIG. 10 , autonomous control of the pallet moving apparatus moving a pallet carrying incoming goods into the rear of a trailer 322 in the receiving area of ​​the warehouse 300 is shown. As shown in FIG. 10 , a manual operating mode of the pallet moving apparatus 301 may be required when unloading incoming goods onto multiple pallets on the rear of the trailer 322. For purposes of the definition of this disclosure, the "manual operating mode" of the pallet moving apparatus covers operations in which an operator manually controls the movement of the pallet moving apparatus 301. This includes, but is not limited to, controlling the drive assembly and steering mechanism to move and steer the pallet moving apparatus across the floor, manually controlling the first and second sets of wheels to step over one or more planks in the lower deck of the pallet 18, and / or manually controlling a lift mechanism to raise and lower multiple forks. Once unloaded from the trailer 322, the pallet moving device 301 transporting the pallet 18 can be switched from manual mode to autonomous mode so that the movement of the pallet moving device around the warehouse and then to its final destination can be controlled autonomously.

[0059] A warehouse may be divided into multiple zones or regions. The multiple zones or regions may include an autonomous zone for allowing a pallet moving apparatus to operate in autonomous mode and a manual zone for allowing the pallet moving apparatus to operate in manual mode. The autonomous zone may be demarcated from the manual zone by a barrier or any suitable partition. Examples of boundaries between the manual and autonomous zones include, but are not limited to, a physical barrier with one or more apertures 330 for the pallet moving apparatus to transition between the autonomous and manual zones, or an invisible barrier such as a light barrier. Another example includes a warehouse with a wireless region that covers the autonomous zone so that the pallet moving apparatus can receive signals from a central controller carrying instructions to operate in autonomous mode, i.e., the range of the wireless region extends to the edge of the autonomous zone. Beyond the autonomous region, the pallet moving apparatus is out of range of the wireless region and therefore cannot receive signals from the central controller, in which case the pallet moving apparatus switches to manual operating mode. In the particular example shown in FIGS. 10 and 14 , autonomous zone 324 is separated from manual zone 326 by a physical barrier 328 comprising one or more apertures 330. When in autonomous zone 324, the pallet moving device automatically switches or transitions to autonomous mode. Similarly, the pallet moving device switches to manual operating mode when in a manual zone. Transition to manual mode can occur automatically when the pallet moving device is in manual zone 326 of the warehouse. Dividing the warehouse into multiple zones and having the operation of the pallet moving device depend on whether the pallet moving device is in a manual zone or an autonomous zone prevents an operator from attempting to transition the pallet moving device to manual operating mode when in an autonomous zone of the warehouse, and vice versa. Alternatively, there may be overlap between manual zone 326 and autonomous zone 324. It should be understood that in an alternative configuration, the manual and autonomous zones may be contiguous.

[0060] To convert the pallet mover 301 from the autonomous mode to the manual mode, the pallet mover 301 according to the third example of the present disclosure includes a user manual interface 306 having an interface portion 308 configured to couple with a steering mechanism and drive assembly including drive wheels 314 of the pallet mover 301 to control the direction and movement of the pallet mover 301. The interface portion 308 may be configured to electrically couple with the steering mechanism and drive assembly to manually control the movement of the pallet mover 301. Signals generated by the user manual device 306 are supplied to the steering mechanism and drive assembly 314 via the interface portion 308 and the control system 32 to control the movement of the pallet mover 301. The interface portion 304 includes, but is not limited to, physical contact between the user manual interface 306, e.g., an electrical contact pad, and the main body 302 of the pallet mover 301, and may also include a short-range wireless link, e.g., Bluetooth®, between the user manual interface and the pallet mover. The wireless link is established when the user manual interface establishes contact with the main body of the pallet mover. The pallet mover 301 may include one or more sensors configured to sense the presence of the user manual interface 306 when coupled to the pallet mover body 302. Such sensors include various coupling sensors, including, but not limited to, proximity sensors, mechanical switches, etc. The coupling sensors are coupled to the pallet mover's control system, which processes signals from the coupling sensors and switches the operation of the pallet mover between an autonomous mode and a manual mode in response to one or more signals from the coupling sensors. For example, when the coupling sensors sense that the user manual interface 306 is coupled to the pallet mover body, a signal is sent to the control system 32, which processes the signal to switch the operation of the pallet mover from the autonomous mode to the manual mode, allowing the pallet mover to be controlled by the user manual interface 306.

[0061] During operation, an operator can move the pallet moving device 301 to the edge of an autonomous zone and disengage the user manual interface from the pallet moving device. The pallet moving device can then perform one or more autonomous actions. For example, a central controller may communicate a location in the autonomous zone to the pallet moving device. The pallet moving device will then autonomously move to this location. This location may be adjacent to one of multiple stations located within the autonomous zone. The station may be a decant station used to decant product items from the pallet so that they can be introduced into the automated storage and retrieval system. This decant function may be performed by a human operator, a robotic picking arm, or a combination of the two. Once all of the product items have been removed from the pallet, the pallet moving device may place the empty pallet in a pallet storage location. After the pallet moving device has processed the pallet, the pallet moving device may return to the manual zone so that the pallet moving device can be attached to an additional user manual interface to complete additional tasks.

[0062] 9 and 11, the user manual interface 306 includes a manual steering mechanism 310 coupled to the steering mechanism of the pallet mover such that the user manual interface can override the control system 32 and manually control the direction of movement of the pallet mover. Also valid in the present disclosure is for the user manual interface 306 to override the control system 32 and independently control the movement of the first and second sets of wheels to clear one or more planks in the lower deck of the pallet as discussed above. For example, the user manual interface can include a switching mechanism (e.g., one or more physical switches) for independently controlling the retraction and deployment of the first and second sets of wheels in a substantially vertical direction to clear one or more planks in the lower deck of the pallet. In addition to or as an alternative to manually controlling the steering mechanism via the control system 32 of the pallet mover, the user manual interface can have its own control system (not shown) that operates independently of the control system 32 of the pallet mover 301 to control the movement of the pallet mover. For example, the control system of the user manual interface can override the control system of the pallet mover and control operation of the drive assembly and / or steering mechanism and / or first and second sets of wheels. In other words, the user manual interface can be supported by the body of the pallet mover 301. In addition to or as an alternative to manually controlling the pallet mover via the drive assembly and / or steering mechanism of the pallet mover, the user manual interface can have its own independent manual steering mechanism and / or manual drive mechanism with drive wheels for moving the pallet mover. The manual steering mechanism and / or manual drive mechanism can simply be a push-and-pull system in which the operator physically pushes or pulls the user manual interface via the manual steering mechanism and / or manual drive mechanism to move the pallet mover.

[0063] The manual steering mechanism 310, shown in FIG. 8 , includes a tiller arm 315 to be manipulated by an operator to adjust the direction of movement of the pallet mover 301. The tiller arm 315 is coupled to the drive wheel 314 and steering mechanism of the pallet mover such that movement of the tiller arm 315 controls movement of the pallet mover across the floor. As an alternative to manually controlling the direction of movement of the pallet mover with the tiller arm 315, the manual steering mechanism 310 can include a steering wheel 316, as shown in FIG. 11 . Similar to the tiller arm, the direction of movement of the pallet mover is manually controlled by rotating the steering wheel 316. The user manual interface 306 can be a permanent fixture of the pallet mover body 302, or can be integrated into the pallet mover body 302, or can be removable from the pallet mover. In the example shown in FIG. 11 , the pallet mover 301 includes a platform 318 for the operator to stand on while manually steering the pallet mover via the built-in manual steering mechanism 316. The platform 318 is rotatably mounted to the body 302 of the pallet mover 301 and may be movable between an extended position for an operator to stand on and a stowed position in which the platform folds relative to the body 302 of the pallet mover, as shown in FIG. 12 . In the particular example shown in FIG. 12 , the platform 318 is pivotally mounted to the body of the pallet mover by a suitable hinge (not shown). The hinge may include a torsional biasing assembly, e.g., a coil spring, to bias the platform toward the stowed position. The body of the platform may include one or more sensors, e.g., a door sensor, that are activated when the platform is in the stowed position. In response to activation of the one or more door sensors, the control system switches the pallet mover from manual mode to autonomous mode. An advantage of integrating a user manual interface into the body 302 of the pallet mover 301 is the flexibility of the operator to switch operation of the pallet mover from autonomous mode to manual mode simply by moving the platform to the extended position and / or operating a user manual device.However, one of the major drawbacks of integrating a user manual interface with the pallet mover is the need to support the additional weight of the user manual interface when operating in autonomous mode.

[0064] In another aspect of the present disclosure, the user manual interface 306 is detachable from or removably coupled to the main body 302 of the pallet mover, as illustrated in FIGS. 9 and 13. In the example shown in FIGS. 9 and 13, the user manual interface 306 may be a separate, standalone device comprising a main body 312 and a wheel assembly 320 supporting the main body 312 for moving the user manual interface independently of the pallet mover 301, i.e., a system comprising the user manual interface 306 and the pallet mover 301 of the present disclosure. This allows the operator to separate the user manual interface from the main body of the pallet mover when converting the pallet mover to autonomous mode. When coupled to the main body of the pallet mover, the manual steering mechanism 310 can take over control of the drive assembly and / or steering mechanism of the pallet mover. This can be via the pallet mover control system 32 or a separate control system built into the user manual interface; i.e., the separate control system can override the pallet mover control system 32 and manually control the movement of the pallet mover via the manual steering mechanism. To enable the user manual interface to be detached from and reattached to the pallet mover, the user manual interface can include a manual drive mechanism coupled to wheel assemblies 320 of the user manual interface 306. As illustrated in Figures 9 and 13, the steering mechanism can be a tiller arm 315 or a steering wheel 316. One or more coupling sensors discussed above mounted on the body 312 of the user manual device 306 and / or the body 302 of the pallet mover 301 sense the presence of the user manual device 306 when coupled to the body 302 of the pallet mover 301. In the particular example shown in Figure 13, the detachable user manual device 306 includes an integrated or ride-on platform 318 for an operator to stand on and use the manual steering mechanism to maneuver the user manual interface.

[0065] During operation, for example, when unloading the trailer 322 as shown in FIGS. 10 and 14 , an operator can couple the user manual interface 306 to the main body 302 of the pallet moving device 301. The operator can then manually control the movement of the pallet moving device, including the movement of the first and second sets of wheels, through the user manual interface. Upon reaching the target pallet, the operator can manually operate the first and / or second sets of wheels to engage the forks with the target pallet by stepping over one or more planks in the lower deck of the pallet, as discussed above with respect to the first and second examples of this disclosure. Once engaged with the pallet, the operator can manually operate the lift mechanism to lift the pallet off the floor. The lift mechanism can involve extending the first set of wheels so that the forks are elevated above the floor. However, other means for manually lifting the forks are acceptable in this disclosure, such as a hydraulic pump and / or an electric motor coupled to the first and / or second sets of wheels by one or more levers to raise or lower the forks.

[0066] Once engaged with the pallet, the operator can manually steer the pallet mover, via the user manual interface, to a destination where the pallet mover can operate in autonomous mode. The operator can then uncouple the user manual interface from the body 302 of the pallet mover, allowing the pallet mover to operate in autonomous mode, as shown in Figures 10 and 14. Uncoupling the user manual device from the pallet mover involves removing the user manual device 306 from the body 302 of the pallet mover 301. The pallet mover switches to autonomous mode when one or more of the coupling sensors recognizes that the user manual interface is no longer coupled to the body of the pallet mover.

[0067] In all of the examples of pallet movers described with reference to Figures 8-14, the pallet mover may include an actuator for switching between manual and autonomous modes of operation in response to one or more signals from a coupled sensor. Examples of actuators include, but are not limited to, various switches. It will be understood that various changes, modifications, alterations, and combinations in the details, materials, and arrangements of parts and components described and illustrated to illustrate the pallet mover as described herein may be made by those skilled in the art within the principles and scope of the present disclosure.

Claims

1. 1. A pallet moving device for moving a pallet, the pallet comprising a top deck formed from one or more planks and a lower deck formed from one or more planks, the lower deck being spaced apart from the top deck, the pallet moving device comprising: a body including a lift mechanism and a drive assembly for moving the pallet mover; a plurality of forks for lifting and handling pallets, wherein the plurality of forks extend outwardly from the body and are configured to be lifted by the lift mechanism; a first set of wheels and a second set of wheels, each of the first and second sets of wheels independently movable relative to the plurality of forks, the first set of wheels configured to be vertically movable between a stowed position in which it disengages from the floor and a deployed position in which it engages the floor, in use, such that the first set of wheels clears one or more of the planks of the pallet when the plurality of forks are inserted into the pallet; A pallet moving device comprising:

2. 2. The pallet moving apparatus of claim 1, wherein the lifting mechanism is configured to lift the plurality of forks by extending the first set of wheels in the vertical direction relative to the plurality of forks when in the deployed position.

3. 3. The pallet moving device of claim 1, wherein the second set of wheels is configured to be vertically movable relative to the plurality of forks between a deployed position in which it engages the floor and a retracted position in which it disengages from the floor.

4. 4. A pallet moving device according to claim 3, wherein each wheel of the first and / or second sets of wheels is pivotally mounted to a plurality of the forks to allow movement in the vertical direction.

5. 5. A pallet mover according to claim 3 or 4, further comprising a locking mechanism configured to lock the first or second set of wheels in the stowed or deployed position.

6. 3. The pallet mover of claim 1, wherein the second set of wheels is configured to engage the floor and be retractable longitudinally along the plurality of forks between a forward position and a stowed position, the forward position being closer to the first set of wheels than the stowed position.

7. 7. The pallet mover of claim 6, wherein the second set of wheels is biased to the forward position.

8. 8. A pallet moving apparatus according to any preceding claim, further comprising an actuation mechanism operable to independently move the first set of wheels and / or the second set of wheels relative to the plurality of forks.

9. 9. The pallet moving apparatus of claim 8, further comprising a control system configured to operate the actuation mechanism to independently move the first set of wheels and / or the second set of wheels relative to a plurality of the forks.

10. 10. The pallet moving device of claim 9, wherein the pallet moving device is an autonomous pallet moving device comprising a location awareness sensor for detecting a location of the pallet moving device in a direction of movement, and the control system is configured to move the pallet moving device in response to one or more signals from the location awareness sensor.

11. 11. The pallet moving apparatus of claim 10, wherein the location awareness sensor comprises a LiDAR sensor comprising a laser beam source, an optical receiver, and a scanning system for deflecting a laser beam generated by the laser beam source in at least two scanning directions.

12. 12. A pallet moving apparatus according to any one of claims 9 to 11, further comprising a proximity sensor for detecting the presence of an obstacle, the proximity sensor cooperating with the actuation mechanism such that, in use, the actuation mechanism is configured to actuate movement of the first or second set of wheels relative to the plurality of forks in response to a signal from the proximity sensor.

13. The pallet mover of claim 12 , wherein the proximity sensor is disposed at a distal end of at least one of the plurality of forks relative to the body.

14. A pallet mover according to any one of claims 8 to 13, wherein the actuation mechanism comprises at least one linear actuator.

15. 15. A pallet mover according to any preceding claim, wherein a first set of wheels are proximal to distal ends of the plurality of forks and a second set of wheels are proximal to the body of the pallet mover.

16. A pallet mover according to any preceding claim, wherein the drive assembly comprises a drive wheel rotatable about a drive axis, and a drive mechanism for driving the drive wheel about the drive axis.

17. A pallet mover according to any preceding claim, further comprising a steering mechanism for changing the direction of the pallet mover.

18. 18. The pallet mover of claim 17, wherein the steering mechanism is coupled to the drive wheel and configured to rotate the drive wheel about a steering axis that is substantially perpendicular to the drive axis of the drive wheel.

19. 19. A pallet mover according to claim 17 or 18, further comprising a user manual device having an interface portion configured to couple with the steering mechanism and the drive assembly for manually controlling the direction and movement of the pallet mover.

20. 20. The pallet mover of claim 19, wherein the interface portion electrically couples with the steering mechanism and the drive assembly.

21. 21. The pallet mover of claim 20, wherein the user manual device is detachable from the main body of the pallet mover.

22. 22. The pallet mover of claim 21, further comprising a coupling sensor for switching the pallet mover between an autonomous mode of operation and a manual mode of operation in response to one or more signals from the coupling sensor.

23. 23. A pallet moving apparatus according to claim 21 or 22, wherein the user manual device comprises a body and a wheel assembly for moving the body.

24. 24. The pallet mover of claim 23, wherein the user manual device comprises a manual steering mechanism coupled to the wheel assembly for steering the body of the user manual device.

25. A pallet moving apparatus according to any one of claims 19 to 24, wherein the manual steering mechanism comprises a tiller arm or a steering wheel.

26. 26. A pallet moving apparatus according to claim 25, wherein the tiller arm is movable along an arc between a substantially horizontal position and a substantially vertical position.

27. 6. A method of moving / handling a pallet by a pallet moving device according to any one of claims 1 to 5, comprising the step of independently moving the first and second sets of wheels vertically so that a plurality of the forks clear one or more planks in the lower deck of the pallet when inserted into the pallet.

28. The first and second sets of wheels are: a) retracting the first set of wheels to disengage the first set of wheels from the floor; b) moving the pallet mover a first distance toward the pallet such that at least a portion of the plurality of forks enter the pallet; c) deploying the first set of wheels to engage the floor; d) retracting said second set of wheels to disengage said second set of wheels from said floor; e) moving the pallet mover a second distance toward the pallet than in step (b) so that a second portion of the plurality of forks enters the pallet; 28. The method of claim 27, wherein one or more of the planks in the lower deck of the pallet are stepped over by

29. 8. A method for moving / handling pallets by means of a pallet moving device according to claim 6 or 7, comprising the steps of: a) moving the pallet mover a first distance toward the pallet such that first portions of the plurality of forks enter the pallet; b) storing the second set of wheels longitudinally along the plurality of forks relative to the plurality of forks; c) moving the pallet mover a second distance toward the pallet so that a second portion of the plurality of forks enters the pallet; A method comprising:

30. 30. The method of any one of claims 27 to 29, further comprising the step of raising the plurality of forks by extending the first set of wheels in a substantially vertical direction.

Images