The present invention relates to the general field of lifting devices and, more particularly, to a mobile and modular lifting device particularly adapted for raising at least a portion of at least one vehicle sufficiently above ground for allowing maintenance personnel to substantially freely access the underside thereof with a mechanics' wheeled creeper board.
There is often a need to lift a car or other vehicle for maintenance. Devices used to that effect are either relatively expensive or difficult to use in confined spaces. They are therefore not well suited to use in a home garage or in small shop, which very often provide very little space around a vehicle on which work is required.
Thus, there is a need on the market for an improved device that avoids the aforementioned disadvantages. An object of the present invention is therefore to provides such an improved device.
In a broad aspect, there is provided a lift for lifting a vehicle above a ground surface, the lift comprising: an elongated front module insertable under the vehicle and a rear module extending longitudinally from the front module; the front module defining longitudinally opposed front module front and rear ends, the front module including a truck supporting four support arms usable for supporting the vehicle, the front module also including a pair of front wheels assemblies mounted to the truck laterally spaced apart from each other and provided adjacent the front module front end; the rear module including a head frame, an actuator assembly mounted to the head frame and a rear wheels assembly; wherein the front and rear wheel assemblies include respectively front and rear wheels; and wherein the actuator assembly is operatively coupled to the front and rear wheel assemblies to selectively move the front and rear wheel assemblies between a lowered configuration and a raised configuration, wherein the front and rear wheels are moved away from the head frame and truck when the front and rear wheels assemblies are moved from the lowered to the raised configuration so that head frame and truck are supported further above the ground by the front and rear wheels in the raised configuration than in the lowered configuration.
There may also be provided a lift wherein the front module further includes a pair of intermediate wheel assemblies laterally spaced apart from each other and provided adjacent the front module rear end, the intermediate wheel assemblies each including an intermediate wheel; and the actuator assembly is further operatively coupled to the intermediate wheel assemblies to selectively move the intermediate wheels substantially coplanarly with the front and rear wheels so that the intermediate wheels also support the front module in the raised configuration.
There may also be provided a lift wherein the front and rear modules are selectively detachable from each other.
There may also be provided a lift further comprising a height lock for selectively locking the intermediate and front wheel assemblies relative to the truck so that the intermediate and front wheels remain fixed relative to the truck when the rear module is detached from the front module.
There may also be provided a lift, wherein the front and intermediate wheel assemblies each include a leg and a pivot for mounting the leg to the truck, the leg defining leg actuating and supporting segments extending away from each other at the pivot, the front and intermediate wheels being mounted to the leg supporting segment opposed to the pivot; the front module including a pair of push rods movable longitudinally therealong and engaging the actuating segment of the front and intermediate wheel assemblies so that moving the push rods along the truck pivots the front and intermediate wheel assemblies about their respective pivots to move between the lowered and raised configurations.
There may also be provided a lift wherein the height lock includes a pin for selectively engaging the push rods and the truck for maintaining the push rods static relative to the truck when the intermediate and front wheel assemblies are in the raised configuration.
There may also be provided a lift wherein the height lock includes a ratchet mechanism operatively coupled to the push rods for preventing the push rods from moving in a direction leading the front and intermediate wheel assemblies to move towards the lowered configuration while allowing the push rods to move in a direction leading the front and intermediate wheel assemblies to move towards the raised configuration, the height lock also including a release mechanism operative for selectively releasing the ratchet mechanism from the push rods to allow the push rods to move both frontwardly and rearwardly.
There may also be provided a lift wherein the rear module further includes a pair of auxiliary wheel assemblies laterally spaced apart from each other and provided between the rear and intermediate wheel assemblies, the auxiliary wheel assemblies each including an auxiliary wheel; the actuator assembly is further operatively coupled to the auxiliary wheel assemblies to selectively move the auxiliary wheels substantially coplanarly with the front and rear wheels.
There may also be provided a lift further comprising a vehicle support mounted to the rear module and configured and sized for supporting part of the vehicle when the front and rear modules are detached from each other.
There may also be provided a lift, wherein the support arms are movable between a retracted configuration wherein the vehicle supports are in register with the truck and an extended configuration wherein the vehicle supports protrude laterally from the truck.
There may also be provided a lift further comprising a caster wheel mounted to the truck at the front module front end and protruding downwardly from the truck to a greater extent than the front wheel assemblies when the front wheel assemblies are in the lowered configuration so that the front module is supported by the caster wheel in the lowered configuration.
There may also be provided a lift wherein the truck includes two longitudinally extending lift forks and at least two lift fork cross members extending transversally and in a longitudinally spaced apart relationship between the lift forks.
There may also be provided a lift wherein the head frame defines head frame upper and lower ends; the rear wheel assembly includes a leg pivotally mounted to the head frame through a pivot provided at the head frame lower end, the rear wheel being mounted to the leg opposed to the head frame; the actuator assembly includes an actuator extending between the leg and the head frame at the head frame upper end; wherein the actuator is movable between retracted and extended configurations to pivot the leg relative to the head frame to move the rear wheel between the raised and lowered configurations.
There may also be provided a lift wherein the actuator is a hydraulic cylinder.
There may also be provided a lift wherein the actuator is mounted to the leg through a pin located inside an elongated slot defined in the leg so that the pin can both move along the slot and pivot relative thereto.
There may also be provided a lift wherein the elongated slot is provided adjacent and substantially vertically in register with the rear wheel.
There may also be provided a lift wherein the rear module further includes a pair of auxiliary wheel assemblies laterally spaced apart from each other and provided between the rear and intermediate wheel assemblies, the auxiliary wheel assemblies each including an auxiliary wheel; the leg includes an auxiliary wheel actuating segment extending away from the pivot with the pivot provided between the auxiliary wheel actuating segment and the wheel the rear module further includes a pair of push rods movable longitudinally along the head frame to move the auxiliary wheel assemblies between the raised and lowered configurations; the push rods are each mounted to the auxiliary wheel actuating segment through a pin located inside an elongated slot defined in the leg so that the pin can both move along the slot and pivot relative thereto; wherein pivoting the leg relative to the head frame moves the push rods longitudinally along the head frame.
There may also be provided a lift wherein the leg is mounted to the head frame through a pin located inside an elongated slot defined in the head frame hat the pin can both move along the slot and pivot relative thereto.
There may also be provided a lift wherein the rear wheel is mounted to the rear wheel assembly so as to be pivotable about a substantially vertical pivot axis relative to the head frame.
There may also be provided a lift wherein the support arms are length adjustable.
There may also be provided a lift wherein the device front module is provided with an auxiliary actuating system for selectively moving the intermediate and front wheel assemblies to change a height of the truck when the device front module is detached from the device rear module.
Advantageously, the combination of the detachable front and rear modules, and the locking elements, allows maintenance personnel to use the device rear module only when raising or lowering the vehicle is necessary. Thus, there is no cumbersome lifting actuator near or around the vehicle when the device rear module is not in use.
In some embodiments, the lift includes a plurality of caster wheels mounted along selected underside portions of the truck and suitably sized and configured so as to maintain the front and intermediate wheel assemblies at least slightly above ground when the lift is in the lowered configuration. Thus, advantageously, the lift can be freely moved around in any user selected position using the draw handle, rear wheels and the 360 degree caster wheels.
In some embodiments, the proposed lift can lower and raise the truck over a relatively large range of motion, so that the lift is adapted for raising above ground a vehicle, such as a performance car or the like, which typically have low clearance underneath.
Further advantageously, the proposed lift raises the vehicle without the use of long and cumbersome support members extending horizontally along the support surface. Thus a mechanics' wheeled creeper board can be freely moved around the relatively small footprint occupied by the individually spaced apart wheel assemblies of the device.
Further advantageously, in some embodiments, the proposed lift can be used in private garages and small maintenance shops having very limited floor space. Accordingly, when not in use, the lift can have its rear module stowed away in a corner of the shop, and the front module conveniently stowed away on a side edge and leaning parallel against a wall.
Furthermore, when the front and rear modules are detachable from each other, each of the front and rear module may be used to raise at least part of a respective vehicle, so that a single lift is usable to work on two vehicles simultaneously.
The present application incorporates by reference the foreign priority document GB2114143.7 filed Oct. 1, 2021.
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of some embodiments thereof, given by way of example only with reference to the accompanying drawings.
The terms “substantially” and “about” are used throughout this document to indicate variations in the thus qualified terms. These variations are variations that do not materially affect the manner in which the invention works and can be due, for example, to uncertainty in manufacturing processes or to small deviations from a nominal value or ideal shape that do not cause significant changes to the invention. Also, directional terminology, such as “above”, is used with reference to a typical use of the proposed device on a level ground surface. This terminology is used for convenience and should not be used to unduly restrict the scope of the present invention.
The modular lifting device 100 comprises a truck 101. Referring to
The modular lifting device 100 further includes a lifting actuator, or actuator assembly, 110 mounted centrally on the rear wheel axle 106, extending substantially vertically upwardly therefrom, and terminated with an actuator 112 at an upper end thereof, wherein the lifting actuator 110 and actuator 112 cooperatively form a steering axis 114 extending vertically centrally there through.
The modular lifting device 100 further includes a handle bar 116 having an elongated configuration and defining a handle bar lower end 118, an opposed handle bar upper end 120 and an extension bar 117 extending there between. The handle bar lower end 118 is pivotably connected to a lower rearward portion of the lifting actuator 110 that is located substantially adjacently relative to an upper circumferential portion of the pair of rear wheels 108. The handle bar 116 further includes a control actuator 124 (seen for example in
The modular lifting device 100 further includes a draw crossbar 126 having a draw crossbar intermediate portion 128 rotably coaxially mounted about a lower portion of the lifting actuator 110, and a pair of draw crossbar pivot pins 130 extending diametrically distally away relative to one another on each side of the draw crossbar intermediate portion 128.
The modular lifting device 100 further includes a head frame 138 including a head frame upper portion 134, lower portion 136, rearward portion 132, forward portion 140 and opposed lateral sides 142 respectively.
The head frame upper portion 134 is adapted for engaging an upper end portion of the actuator 112 so as to be vertically supported thereby and rotatable about the steering axis 114 relative to the assembly represented by the lifting actuator 110, handle bar 116 and rear wheels 108.
The truck 101 includes at least two lift forks 144, each one in the at least two lift forks 144 having a substantially elongated configuration extending forwardly relative to the head frame 138. The at least two lift forks 144 each have a lift fork rearward end connected adjacent a lower edge of the head frame forward portion 140, and adjacently a respective one of the head frame lateral sides 142. Furthermore, the at least two lift forks 144 extend in a parallelly spaced apart relationship relative to one another, and horizontally forwardly therefrom.
The modular lifting device 100 further includes a pair of push rods 150. Each one in the pair of push rods 150 having an elongated configuration and including a push rod rearward end 152, a push rod forward end 154 and a push rod intermediate portion extending therebetween. Each push rod 150 is furthermore extending substantially longitudinally and parallelly along an underside portion of a respective one of the two laterally outer most lift forks 144 of the modular lifting device 100. The push rod rearward end 152 includes a transversally extending push rod actuating pin 156.
As illustrated for example collectively in
Each front wheel assembly 160 further includes at least one wheel 168 rotably mounted on a wheel axle extending transversally between the pair of L-shaped wheel lever legs 162 and proximally the wheel lever leg forward end 164. Each front wheel assembly 160 further includes a wheel assembly pivot axle 170 extending transversally between the pair of L-shaped wheel lever legs 162 and substantially at the junction of the wheel lever leg forward end 164 with the wheel lever leg rearward end 166.
Each front wheel assembly 160 further includes a wheel assembly actuating pin 172 extending transversally between the pair of L-shaped wheel lever legs 162 and proximally the wheel lever leg rearward end 166.
Each opposed ends of the wheel assembly pivot axle 170 is rotably mounted to the truck 101 through oppositely facing walls of the respective lift fork 144, and the wheel assembly actuating pin 172 is pivotally transversally engaged through a respective push rod forward end 154.
The modular lifting device 100 further includes a pivoting lever 180. The pivoting lever 180 includes a pivoting lever axle 182 rotably mounted horizontally transversally along the head frame rearward portion 132. The pivoting lever acts as a rear wheel assembly leg.
The pivoting lever 180 further includes a pair of pivoting lever upper arms 184 extending substantially radially distally and in a parallelly spaced apart relationship from a peripheral surface portion of the pivoting lever axle 182 towards the draw crossbar 126. A distally extending end portion of each pivoting lever upper arm 184 is pivotally mounted on a respective pivot pin in the pair of draw crossbar pivot pins 130. The pivoting lever 180 further includes a pair of pivoting lever lower arms 186 extending substantially radially distally downwardly and in a parallelly spaced apart relationship from a peripheral surface portion of the pivoting lever axle 182.
Each pivoting lever lower arm 186 is pivotally mounted on a push rod actuating pin 156 of a respective push rod rearward end 152.
The truck 101 further comprises at least two lift fork cross members 190 extending transversally and in a longitudinally spaced apart relationship between the at east two parallelly extending lift forks 144, so as to provide transversal structural rigidity there between.
The modular lifting device 100 further comprises at least a forward and a rearward load support arm arrangement 192, or support arms, mounted on a respective one of the lift fork cross members 190. Each one of the forward and rearward load support arm arrangements 192 are suitably sized and configured for engaging at least two spaced apart underside portions of a vehicle 500.
The modular lifting device 100 further comprises a pair of auxiliary wheel assemblies 194, each one in the pair of auxiliary wheel assemblies 194 having a same size, configuration and mounting arrangement as the front wheel assemblies 160 but is located substantially adjacently the head frame 138.
Each rear wheel assembly 194 is provided with at least one pair of laterally spaced apart wheels 169 for contacting the support surface 520. The pair of wheels 169 are sufficiently spaced apart for allowing the respective push rod 150 to be freely inserted there between when the modular lifting device 100 is in the device lowered position. This aspect allows the assembly represented by the front and auxiliary wheel assemblies 160 and 194, the lift forks 144 and load support arm arrangement 192 to have a substantially low height profile, which is useful for insertion under a vehicle having limited height clearance underneath.
Referring to
Furthermore, each one in the pair of pivoting lever lower arms 186 has its distally extending end defining a lower arm elongated slot 202 extending longitudinally and transversally there through. The lower arms elongated slot is pivotally mounted on a respective one of the push rod actuating pin 156, so as to allow an extended and substantially vertical and forward movement of the push rod rearward end 152 relative to the pivoting lever axle 182 when the modular lifting device 100 is moved from the device lowered position to the device raised position since the push rod actuating pin 156 can both slide along the elongated slot 202 and pivot relative thereto.
Typically, a high-load bearing 204 is mounted on each one of the draw crossbar pivot pins 130 and push rod actuating pin 156 respectively. Furthermore, the upper and lower arm elongated slots 200 and 202 define a slot width that is sufficiently greater than the diameter of the respective high-load bearing 204 so as to allow the latter to freely roll along one or the opposed elongated edge of the respective elongated slot 200 and 202.
Referring now to
Furthermore, each lever axle engaging elongated slot 206 define a slot width that is sufficiently greater than the diameter of the respective high-load bearing 208 mounted on the pivoting lever axle 182, to allow the high-load bearing 208 to freely roll along one or the opposed elongated edge of the respective lever axle engaging elongated slot 206.
The lifting actuator 110 is user selectively movable from a lifting actuator retracted position to a lifting actuator extended position. This operation can vary depending on the type of lifting actuator involved. For example, the lifting actuator is a hydraulic cylinder. As seen for example from
In some embodiments, each wheel lever leg forward end 164 has a length dimension suitably sized for allowing the head frame 138, lift forks 144 and load support arm arrangements 192 to be raised up to between 10 and 20 inches (25.4 cm and 50.8 cm) above the support surface 520, when the lifting actuator 110 is user selectively moved from the lifting actuator retracted position to the lifting actuator extended position.
Thus, with the lift forks 144 suitably positioned under a vehicle 500, and the load support arm arrangements 192 suitably adjusted so as to contact predetermined support portions underneath the vehicle 500, the latter may be sufficiently raised such that the wheels 502 thereof are no more in contact with the support surface 520, as illustrated in
Advantageously, the modular lifting device 100 of the present invention raises the vehicle 500 without the use of long and cumbersome support members extending horizontally along the support surface 520. Thus a mechanics' wheeled creeper board can be freely moved around the relatively small footprint occupied by the wheel assemblies 160 and 194 of the device in their fully deployed position.
The modular lifting device 100 may further comprise additional lift forks 144, push rods 150 and wheel assemblies 160, 194 assemblies located in a spaced apart relationship between the two outermost lift forks 144.
As illustrated collectively in
In some embodiments, the lifting actuator 110 is a conventional hydraulic cylinder and pump arrangement with the handle bar 116 suitably configured and sized for actuating the pump of the hydraulic cylinder when raised and lowered about its pivoting connection with the lifting actuator 110. For example, the hydraulic cylinder is a multi-stage telescopic cylinder. Thus, as would be familiar to someone versed in hydraulic systems, the overall vertical dimension of the head frame 138 may be relatively smaller than if a single stage hydraulic cylinder was used. Other types and configurations of known lifting actuators are also possible such as, for example, an electrically powered lifting actuator or a pneumatic lifting actuator. Furthermore, in some embodiments of the modular lifting device 100 (not shown in the figures), the rear wheels 108 may be electrically powered through an electrical motor, battery, brakes and control actuator arrangement.
Referring collectively to
The pair of user releasable connector arrangements 250 is located along a longitudinal portion of each lift fork so as to be laterally in register relative to one another, and typically located adjacent the head frame 138. Furthermore, the pair of user releasable connector arrangements 250 is at a sufficient forward distance away from the head frame 138 to allow a lift fork cross member 190 and load support arm arrangement 192 located between the head frame 138 and the pair of releasable connector arrangements 250, as seen for example in
The addition of an extra pair of intermediate wheel assemblies 195, in cooperation with the user releasable connector arrangements 250, allows the modular lifting device 100 to lift a complete vehicle 500 off the ground using the device front module 258 (as illustrated in
Referring more particularly to
Each paired fork male and female tubular connectors 253 and 255 are user selectively rigidly engaged with one another through at least one, but typically at least two fork locking fasteners 257 such as threaded bolts or equivalent, engaged through suitably corresponding threaded bores extending downwardly through both fork male and female tubular connectors 253 and 255.
Each one in the pair of releasable connector arrangements 250 further includes paired and compatibly shaped and sized push rod male and female connectors 262 and 264 longitudinally distally extending from the corresponding free ends of the push rod rearward and forward portions 256 and 261. Each paired push rod male and female connectors 262 and 264 are user selectively rigidly engaged with one another through at least one push rod locking fastener 270, such as a threaded bolt or equivalent provided with an extension segment 271 between the threaded portion and the bolt head.
The push rod locking fastener 270 is first engaged through a connector elongated slot 272, then fastened through the engaged push rod male and female connectors 262 and 264.
As can be observed in
As can be observed in sequential views in
As exemplified in the drawing, the male tubular connector 253 and male push rod connector 262 are mounted on the device rear module 252, while the female tubular connector 255 and female push rod connector 264 are mounted on the device front module 258. Other equivalent male and female corresponding assemblies are also possible, including selected fasteners engaged laterally instead of vertically.
Typically, the device front module 258 further includes at least one additional pair of wheel assemblies 195 and caster wheels 197 mounted adjacently the rear ends of the lift fork forward portions 260. Thus, as exemplified in sequential views in
Thus, the modular lifting device 100 of the present invention can be advantageously used in private garages and small maintenance shops having very limited floor space. As exemplified in
In some embodiments of the invention, the modular lifting device 100 further comprises a user selectively releasable locking element 300, or height lock. The releasable locking element 300 is suitably sized and configured for allowing a user to selectively and releasably lock the modular lifting device 100 in a raised position above the ground.
Referring to
The releasable locking element 300 further includes at least one, but typically a plurality of longitudinally spaced apart and laterally extending push rod lock pin through-holes 304 located along a longitudinal portion of each push rod 150, and individually laterally in register with the fork lock pin through-hole 302 when the modular lifting device 100 is moved from the lifting device lowered position to the lifting device raised position. Typically, releasable locking element 300 may also selectively lock the intermediate and front wheel assemblies 195 and 160 relative to the truck so that the intermediate and front wheels 195 and 160 remain fixed relative to the truck when the rear module 252 is detached from the front module 258.
The releasable locking element 300 further includes a pair of elongated lock pins 306 suitably sized and configured for engaging in a snug fit relation laterally aligned fork lock-pin through-holes 302 and push rod lock-pin through-holes 304 extending through each lift fork 144 of the truck, so as to safely maintain the vehicle 500 at user selected raised position above ground. Thus, the lock pins 306 are usable to maintain the push rods static relative to the truck when the intermediate and front wheel assemblies 195 and 160 are in the raised configuration
It is contemplated that a single elongated lock pin (not shown in the figures), having a suitably extended length dimension, may be used to lockingly engage the laterally corresponding fork lock-pin through-holes 302 and push rod lock-pin through-holes 304 in one operation. Thus, for safety reasons, no single lock pin 306 may be forgotten engaged in, or left out, of the lock-pin through-holes, relative to the other one.
Referring more particularly to
Preferably, each releasable linear ratchet arrangement 310 includes a pair of toothed lock members 312 mounted within the lift fork 144 and spring-biased oppositely inwardly centrally towards a compatibly shaped toothed longitudinal portion 314 of the push rod 150. The spring-biased toothed lock members 312 and the toothed longitudinal portion 314 of the push rod 150 are suitably sized and configured for directionally lockingly engage one another as the push rod 150 is moved forwardly (e.g. as the modular lifting device 100 is moved towards the device 100 raised position).
Each releasable linear ratchet arrangement 310 further includes a ratchet release lever 316, or release mechanism, adapted for moving each paired toothed lock members 312 laterally distally away from one another, when moved from a locked to an unlocked lever position, so as to release their locking engagement with the toothed longitudinal portion 314 of the push rod 150.
It is contemplated that a single elongated ratchet release lever (not shown in the figures), having a suitably extended length dimension, may be used to simultaneously engage or release all laterally corresponding releasable linear ratchet arrangements 310 along the lift forks 144. Thus, for safety reasons, no single ratchet release lever 316 may be forgotten engaged or released relative to the other one.
In the figures, only the device front module 258 is provided with the releasable locking element 300, but it is to be understood that lift fork portions of each one of the device rear and front modules 252 and 258 respectively, may be provided with the releasable locking element 300.
Referring to
In some embodiments, the modular lifting device 100 further comprises a support arm auxiliary support member 326 mounted on the surface of each lift fork 144, and laterally in register with each lift fork cross member 190. Each support arm auxiliary support member 326 is suitably sized and configured for slidably engaging an underside portion of a respective support arm 320. Thus, when in the laterally deployed position, each rotatable support arm 320 may support a portion of the underside of the vehicle 500 in a substantially stable counter-lever configuration.
In some embodiment, each rotatable support arm 320 is suitably sized and configured so as to conveniently allow both support arm 320 to be retracted longitudinally parallelly in a stowed and compact position in register with the truck, which can be particularly advantageous for transport and usage in spaced limited private garages at home, as illustrated in
As exemplified in
Thus, when mounted on the lift fork cross member 190 of the device rear module 252 of the modular lifting device 100, as illustrated in
As exemplified in
In some embodiments of the invention, as best illustrated in
Advantageously, the modular lifting device 100, when in the device lowered position, can be freely moved around in any user selected position, either assembled or with the device rear and front modules detached from one another.
As illustrated in sequence in
In some embodiments, each caster wheel 197 includes a spring-biased suspension arrangement, as illustrated in
Typically, as best illustrated in
Also, as illustrated in
Typically, as best illustrated through
Referring to
The elements in the various structures and assemblies of the modular lifting device 100 are for example made of suitably rigid steel commonly found in vehicle lifting devices used for rising partially or completely a vehicle above a support surface.
Furthermore, the elements in the various structures and assemblies of the modular lifting device 100 are sized and configured for stably and safely raising off the support surface 520 at least the weight of a relatively large sedan automobile 500 or pickup truck.
It is important to note that, for the purpose of clarity of the drawings, the relative size and proportions of the elements in the various structures and assemblies shown in the figures of the modular lifting device 100, have been reduced relative to their respective sizes and proportions that would be required for raising the total weight of a vehicle 500 above ground.
A method of using the modular lifting device 100 will now be described.
In a first step, the modular lifting device 100 is used to lift above the ground a complete first vehicle 500 resting on the device front module 258 (as illustrated in
In a second step, engage the locking element 300, so as to lock the device front module 258 in a raised position.
In a third step, release the connector arrangements 250, so as to detach the device rear module 252 from the device front module 258.
In a fourth step, use the device rear module 252 to raise the front, side, or rear end of a second vehicle 500 (as illustrated in
Referring collectively to
For example, the auxiliary actuation system 600 includes a hydraulic actuator 602 operatively coupled to hydraulic cylinders 604 to selectively lengthen or shorten the hydraulic cylinders 604. Conventional hoses (not shown in the drawings) extend between the hydraulic actuator 602 and the hydraulic cylinders 604. The hydraulic cylinders 604 are operatively coupled to the intermediate and front wheel assemblies 195 and 160 to selectively move the intermediate and front wheel assemblies 195 and 160 between the raised and lowered configurations.
The hydraulic actuator 602 includes a conventional control valve 606 and a manual actuator 608, for example a lever coupled to a pump. When the control valve 606 is open, fluids within the hydraulic actuator and hydraulic cylinders 604 can move freely with very little resistance, allowing operation using the rear module 252 as described above. Once the control valve 606 is closed, one can use the manual actuator 608 to pump a hydraulic fluid towards the hydraulic cylinders 604 to lengthen them. Shortening of the hydraulic cylinders 604 occurs typically passively by opening the control valve 606 and letting gravity pull on the truck 101 and any load supported thereby.
For example, the hydraulic cylinders 604 each extend between the truck 101 and the push rods 150, and more specifically between the lift forks 144 and the push rods 150, so that lengthening and shortening the hydraulic cylinders 604 move the push rods 150, which results in actuation of the intermediate and front wheel assemblies 195 and 160 as described above. Typically, the hydraulic cylinders 604 are oriented such that when the truck 101 can be lowered passively by letting the hydraulic fluids circulate in the actuation system 602. Raising the truck 101 requires one to pump the hydraulic fluids, either manually using the manual actuator 608 or through a suitable motor.
Any suitable number of hydraulic cylinders 604 may be provided, depending on their lifting capacity. Typically, at least one hydraulic cylinder 604 is provided for each push rod 150. To better balance forces on the push rods 150, more hydraulic cylinder can be provided, for example 8 hydraulic cylinders 104 provided pairwise on each side of the push rods adjacent the intermediate and front wheel assemblies 195 and 160. If the base front module 258′ can be locked at a specific height, one needs to unlock the base front module 258′ before operating the auxiliary actuation system 600. In some embodiments, the auxiliary actuation system acts 600 as a locking element, allowing omission of the mechanical locking element 300 described hereinabove, as closing the valve 606 locks the height of the device front module 258′ if the manual actuator 608 is not operated.
Although the present invention has been described hereinabove by way of exemplary embodiments thereof, it will be readily appreciated that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, the scope of the claims should not be limited by the exemplary embodiments, but should be given the broadest interpretation consistent with the description as a whole. The present invention can thus be modified without departing from the spirit and nature of the subject invention as defined in the appended claims.
Number | Date | Country | Kind |
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2114143.7 | Oct 2021 | GB | national |