Pallet truck

A pallet truck includes a front frame having at least one fork and being connected to a drive unit through a lift cylinder, a plug-in battery assembly, a hydraulic supply system and a plug-in controller assembly connected to the front frame, and an operator handle connected to the drive unit. The pallet truck may include a rear frame having caster wheel assemblies that are mounted from above, and where the rear frame is connected to the drive unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Chinese Patent Application No. 201820566739.2, filed Apr. 19, 2018, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The invention relates to a material handling equipment, and more particularly to pallet trucks having a plug-in controller assembly and/or plug-in battery assembly.

BACKGROUND

Pallet trucks are used as logistics equipment to carry goods. The forks of a manual pallet truck are inserted into holes of a pallet when used in a pallet handling station. A hydraulic system of a manual pallet truck is driven by manpower to cause the lifting and descending of cargo on a pallet, and the pallet handling operation is completed by manpower of the user pulling the pallet truck. A pallet truck is the most simple, effective and common loading and unloading material handling tool in pallet conveyance of a pallet handling station.

The introduction of powered pallet trucks reduced the extent of manpower required. But at present, there still are some problems with existing pallet trucks. First, the structure of a typical existing pallet truck is basically divided into front and rear frames connected by a lift cylinder. A battery box typically is located in front of the lift cylinder, and a controller and hydraulic supply system are located behind the battery box. The size of the whole vehicle is relatively large, the turning radius is large, the width of an aisle required for passage is large, and as such, the use is limited.

Second, in the existing technology, lithium batteries with small size and light weight bring more convenience to material handling trucks. However, most batteries require some disassembly of the pallet truck to be removed from the pallet truck, which is inconvenient and can be time consuming with respect to operations and charging.

Third, the controller of an existing pallet truck is fixedly connected to the equipment, typically covered by a body panel and the equipment needs to be disassembled to be repaired and/or replaced when a failure occurs. At that time, the vehicle cannot be used, which greatly affects the timely and efficient use of the equipment.

Fourth, most existing material handling vehicles are equipped with two auxiliary caster wheels, and the caster wheels are accessed from below the vehicle, so they may be installed and disassembled only after lifting the entire vehicle, which results in the process of replacement of caster wheels being somewhat cumbersome and unsafe.

SUMMARY

The purpose of this disclosure is to provide a pallet truck that may be smaller and more convenient for installation and maintenance of service related items.

In order to achieve the above purpose, the disclosure provides a pallet truck having a front frame connected to a drive unit through a hydraulic lift cylinder. A hydraulic supply system, a controller assembly and a battery assembly are installed side by side on the front frame, and the battery assembly is located on one side of the lift cylinder. The hydraulic supply system and the controller assembly are located on the other side of the lift cylinder. The battery assembly and the controller assembly are connected to the front frame and configured to be of a plug-in and pull-out type. An operation handle is arranged on the drive unit, and the front frame also is provided with front forks.

In a preferred configuration, the battery assembly includes a battery box that encloses a power source such as a lithium battery, and has a battery cable female plug-in header and a battery signal line female plug-in header, which plugs into a battery base that includes a battery cable male plug-in header and a battery signal line male plug-in header. The lithium battery is fixed in the battery box. The bottom of the battery box is provided with an upward raised hollow guide column, and the upper end of the hollow guide column is provided with the battery cable female plug-in header and the battery signal line female plug-in header. The position of the hollow guide column corresponds to an upward raised guide block on the battery base. Fixed to the upper end of the guide block are the battery cable male plug-in header and the battery signal line male plug-in header. When the battery box is plugged into the battery base, the hollow guide column of the battery box receives the guide block of the battery base and the battery cable female plug-in header and the battery signal line female plug-in header receive and are connected to the battery cable male plug-in header and a battery signal line male plug-in header, respectively.

In a preferred embodiment, the battery box may be formed by fixing a battery top and battery bottom to a battery sidewall, such as by at least one screw respectively. The lithium battery is fixed on the battery bottom, and the hollow guide column is located at a corner of the battery bottom.

Also, in the preferred embodiment, a first battery plug-in bracket is fixed to the upper end of the hollow guide column, and the battery cable female plug-in header and the battery signal line female plug-in header are fixed in the first battery plug-in bracket, such as by at least one screw, respectively. In addition, a battery cable pin assembly and a battery signal line pin assembly are respectively fixed, such as by a least one screw, to the battery cable female plug-in header and the battery signal line female plug-in header.

In the preferred embodiment, fixed to an upper end of the guide block is a second battery plug-in bracket. A battery cable male plug-in header and a battery signal line male plug-in header are fixed in the second battery plug-in bracket at the upper end of the guide block, such as by at least one screw, respectively. Also, a battery cable plug-in pin assembly and a battery signal line plug-in pin assembly are respectively fixed, such as by at least one screw, to the battery cable male plug-in header and the battery signal line male plug-in header.

Also, in the preferred embodiment, the hollow guide column has a height and the guide block has a height that is substantially the same as the height of the hollow guide column, and the battery sidewall has a height and the height of the hollow guide column is greater than two-thirds of the height of the battery sidewall. The use of a tall hollow guide column and guide block help to stabilize and prevent the plug-in battery assembly from loosening due to encountering bumps or vibrations during the use or transportation of the pallet truck.

In the preferred embodiment, the battery assembly includes a handle, a switch and a light emitting diode (LED) lamp respectively mounted on the battery top, with the lamp providing temporary lighting. A battery management system (BMS) module is fixed on the battery bottom. The second plug-in battery bracket also is provided with a clamp having two prongs that engage and releasably retain the first plug-in bracket for the plug-and-pull function of the battery box relative to the battery base.

Additionally, in the preferred embodiment, the controller assembly includes a controller box that encloses a control unit and plugs into a controller base. The control unit is fixed in the controller box, such as by at least one screw, and the lower end of the controller box is provided with a receptacle. The internal top of the receptacle is provided with a controller plug-in bracket, to which is connected a controller cable female plug-in header and a controller signal line female plug-in header. An upper part of the controller base includes a raised socket. The controller box and the controller base are connected when the receptacle of the controller box receives the raised socket of the controller base, which causes the connection of the controller cable female plug-in header to a controller cable male plug-in header and connection of the controller signal line female plug-in header with a controller signal line male plug-in header. When there is a fault in the control unit, the maintenance of the equipment can be completed by simply pulling out and replacing the controller box, which improves the maintenance efficiency and the use efficiency of the equipment.

In the preferred embodiment, the controller box is formed by fixing a back cover to a front cover, such as by at least one screw, and the control unit is fixed on the back cover, such as by at least one screw.

Also, in the preferred embodiment, the internal top of the receptacle is provided with a controller plug-in bracket, which is fixed to the back cover and to the front cover of the controller box, such as by at least one screw, respectively.

In the preferred embodiment, the controller base is provided with a clamp having two prongs that engage and releasably retain the controller plug-in bracket on the controller base, and a controller cable plug-in pin assembly is fixed, such as by at least one screw, to a controller cable male plug-in header and a controller signal line plug-in pin assembly is fixed, such as by at least one screw, to a controller signal line male plug-in header.

Also, in the preferred embodiment, the rear frame includes a pair of caster wheel assemblies. Inner sides of both ends of the rear frame are fixed to mounting brackets, which are connected to the drive unit, respectively. Each mounting bracket is provided with an opening. A lower face of a fixing plate at the top of a caster wheel assembly is fixed to an upper face of the mounting bracket, such as by at least one screw. By adjusting the installation direction of the caster wheel, the caster wheel can be removed from above, so that the pallet truck does not need to be hoisted to disassemble and install a new caster wheel assembly. The structure makes the assembly and disassembly of caster wheel assemblies simpler and safer, and can be completed without other auxiliary work, thus making the maintenance more simple and convenient.

In the preferred embodiment, an outer side of the mounting bracket is vertically fixed to the rear frame, the inner side of the mounting bracket is folded upward to form a connecting side plate, the two sides of the drive unit are fixed to the respective two connecting side plates, such as by at least one screw, respectively, and the opening in the mounting plate extends to the connecting side plate.

The preferred embodiment also includes a lock washer and a flat washer between the screw and the fixing plate at the top of the caster wheel assembly, and the rear frame forms an arc-shaped connection plate as a whole.

The disclosure adjusts the layout of the pallet truck, divides the battery assembly, to be located on one side of the lift cylinder, and the hydraulic supply system and controller assembly, to be located on the other side of the lift cylinder. This reduces the size of the vehicle, the turning radius and the width required for aisle passage, and facilitates use of such pallet trucks in more environments. The controller assembly and the battery assembly are configured for plug-in and pull-out connection to the pallet truck, which facilitates disassembly, assembly and maintenance.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of a pallet truck is described in detail below, and an example of the embodiment is shown in the drawings in which identical or similar labels throughout represent identical or similar elements, or elements with the same or similar functions. The following embodiments described with reference to the drawings are illustrative and are intended to be used to explain, rather than to limit the disclosure.

An example pallet truck P is shown inFIGS. 1-4, with some structure removed for convenience of viewing. The pallet truck P has a front frame1connected to a drive unit4through a hydraulic lift cylinder3. A hydraulic supply system5, a controller assembly6and a battery assembly2are installed side by side on the front frame1. The battery assembly2is located on one side of the lift cylinder3, and the hydraulic supply system5and the controller assembly6are located on the other side of the lift cylinder3. The battery assembly2and the controller assembly6are connected to the front frame1and configured to be of a plug-in and pull-out type. An operation handle7is arranged on the drive unit4, and the front frame1also is provided with front forks8, and the pallet truck P may include a rear frame9connected to an extending outward from the drive unit4.

As shown inFIG. 2, the battery assembly2includes a battery box that encloses a power source, such as a lithium battery206, and plugs into a battery base219, which is configured to be mounted to the front frame1of the pallet truck P. The battery box includes a battery cable female plug-in header210and a battery signal line female plug-in header211. The battery box is fixedly assembled, such as by screws that connect a battery top203and a battery bottom212to a battery sidewall205. The lithium battery206is fixed in the battery box on the battery bottom212, and the battery bottom212is provided with an upward raised hollow guide column212′. The hollow guide column212′ is located at one corner of the battery bottom212. The battery assembly2also may include a handle201, a switch202and a light emitting diode (LED) lamp204mounted on the top cover203of the battery assembly2, respectively. A battery management system (BMS) module220is fixed on the battery bottom212.

A first battery plug-in bracket207is fixed to the upper end of the hollow guide column212′, and the battery cable female plug-in header210and the battery signal line female plug-in header211are fixed in the first battery plug-in bracket207, such as by at least one screw, respectively. In addition, a battery cable pin assembly208and a battery signal line pin assembly209are respectively fixed, such as by a least one screw, to the battery cable female plug-in header210and the battery signal line female plug-in header211.

The position of the hollow guide column212′ corresponds to an upward raised guide block219′ on a battery base219. Fixed to an upper end of the guide block219′ is a second battery plug-in bracket217. A battery cable male plug-in header213and a battery signal line male plug-in header215are fixed in the second battery plug-in bracket217at the upper end of the guide block219′, such as by at least one screw, respectively. Also, a battery cable plug-in pin assembly214and a battery signal line plug-in pin assembly216are respectively fixed, such as by at least one screw, to the battery cable male plug-in header213and the battery signal line male plug-in header215.

The upper end of the raised guide block219′ is provided with the battery cable male plug-in header213and the battery signal line male plug-in header215. The battery box may be plugged into the battery base219, which makes the connection of the battery box with the guide block219′ via the hollow guide column212′. Thus, with the battery assembly2, a user may plug-in the battery box to the battery base219, which causes the battery cable female plug-in header210and its battery cable pin assembly208to receive and connect to the battery cable male plug-in header213and its battery cable plug-in pin assembly214, and causes the battery signal line female plug-in header211and its battery signal line pin assembly209to receive and connect to the battery signal line male plug-in header215and its battery signal line plug-in pin assembly216.

In this example, the hollow guide column212′ has a height and the guide block219′ has a height that is substantially the same as the height of the hollow guide column212′. Also, the battery sidewall205has a height and the height of the hollow guide column212′ is greater than two-thirds of the height of the battery sidewall205. This helps stabilize the connection, which also is aided by having the second battery plug-in bracket217be provided with a releasable clamp218having two prongs that engage and releasably retain the first plug in bracket207when the battery box is plugged into the battery base219. It will be appreciated that in light of the above structures, a user may quickly and conveniently pull-out the battery box from the battery base219, if for instance, the battery needs to be serviced or replaced, without having to disassemble any of the rest of the pallet truck P.

As shown inFIG. 3, the controller assembly6includes a controller box that encloses a control unit602and plugs into a controller base611. The controller box is formed by a back cover601and a front cover603being fixedly connected, such as by at least one screw, and the control unit602is enclosed in the controller box and may be fixed to the back cover601, such as by at least one screw. A lower end of the controller box is provided with a receptacle R that that receives the controller base611. The controller base611is configured to be mounted on the front frame1of the pallet truck P. The internal top of the receptacle R is provided with a controller plug-in bracket604, which is fixed to the back cover601and to the front cover603of the controller box, such as by at least one screw, respectively. A controller cable female plug-in header606is fixed, such as by at least one screw, to a controller cable pin assembly605, and a controller signal line female plug-in header607is fixed, such as by at least one screw, to a controller signal line pin assembly605′.

An upper part of the controller base611includes a raised socket611′. A controller cable male plug-in header608and a controller signal line male plug-in header609are arranged in the socket611′ of the controller base611. Also, a controller cable plug-in pin assembly610is fixed, such as by at least one screw, to the controller cable male plug-in header608, while the controller signal line plug-in pin assembly610′ is fixed, such as by at least one screw, to the controller signal line male plug-in header609. Thus, with the controller assembly6, a user may plug-in the controller box to the controller base611, which causes the socket611′ of the controller base on the front frame1of the pallet truck P to be received by the receptacle R in the bottom of the controller box, and causes the controller cable female plug-in header606and its controller cable pin assembly605to receive and connect to the controller cable male plug-in header608and its controller cable plug-in pin assembly610, and causes the controller signal line female plug-in header607and its controller signal line pin assembly605′ to receive and connect to the controller signal line male plug-in header609and its controller signal line plug-in pin assembly610′.

The controller base611also is provided with a clamp612having two prongs that engage and releasably retain the controller plug-in bracket604when the controller box is plugged-in and the receptacle R receives the raised socket611′ of the controller base611. It will be appreciated that in light of the above structures, a user also may quickly and conveniently pull-out the controller box from the controller base611, if for instance, the controller box needs to be serviced or replaced, without having to disassemble any of the rest of the pallet truck P.

FIG. 4shows a rear frame9of the pallet truck P, which includes a pair of caster wheels. The inner sides of both ends of the rear frame9are fixed to mounting brackets10which are connected to the drive unit4, respectively. Each mounting bracket10is provided with an opening12. A lower face of a fixing plate13at the top of a caster wheel assembly11is fixed to an upper face of the mounting bracket10proximate the respective opening12, such as by at least one screw14.

The outer side of the mounting bracket10is vertically fixed to the rear frame9, and the inner side of the mounting bracket10is folded upward to form a connecting side plate. The two sides of the drive unit4are fixed to the respective two connecting side plates, such as by at least one screw, and the opening12extends to the connecting side plate. A lock washer15and a flat washer16also are arranged between the screw14and the fixing plate13at the top of each caster wheel assembly11, and the rear frame9forms an arc-shaped connection plate as a whole. Having the fixing plates13of the caster wheel assemblies11mount downward against the upper surface of the mounting brackets10advantageously permits disassembly and installation of the caster wheels assemblies11without the cumbersome and potentially dangerous need to lift the pallet truck P.

It should be noted that the above embodiments are only representative examples of the pallet truck of the present disclosure which may have many different configurations. Any equivalent to or modification of the above embodiments according to the essence of the disclosure shall be considered to be within the scope of the disclosure.