Transport trolley having pivotable roller housings
A transport trolley is disclosed and which includes at least two spaced forks, each having at least two load supports; a roller housing pivotally connected to each of the load supports; and rollers mounted within each of the roller housings.
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This invention relates to a trolley for transporting palletised cargo. In particular, the invention concerns a trolley having pivotable roller housings for transporting palletised cargo over uneven ground.
BACKGROUND ARTTrolleys for transporting palletised cargo are known. A problem with some of the known trolleys is that they are unsuitable for transporting cargo over uneven ground, such as a factory floor, a worn floor of a shipping container or a loading ramp. This is particularly true of trolleys that transport heavy loads, such as 25 tonne loads.
It is therefore an object of the present invention to provide a transport trolley that overcomes or at least minimises the problem referred to above.
DISCLOSURE OF INVENTIONAccording to the present invention there is provided a transport trolley having:
at least two interconnected, parallel, spaced forks each having at least two load supports;
a roller housing pivotally connected to each said load support; and
rollers mounted within each said roller housing,
and when the trolley moves over uneven ground, the or each roller housing pivots the rollers to maintain contact with the ground.
The forks may be of any suitable shape, size and construction. Preferably, the forks are shaped for insertion between the blocks of a single-decked pallet. The trolley may have any suitable number of forks. Preferably, the trolley has two forks.
Each fork may have any suitable number of load supports. The number of load supports may depend on the length of the forks and the nature of the palletised cargo that the trolley is to transport. Typically, a trolley for transporting loads about 12 m in length will have two load supports per fork, whereas trolleys for transporting 18 m loads will have three load supports per fork.
Preferably, each fork has a first load support and a second load support. The first and second load supports may be located immediately adjacent one another or they may be spaced from one another. Preferably, the first load support is located at a forward region of each said fork and the second load support is located at a central or rearward region of each said fork. If the second load support is located at the central region, then the trolley may further have one or more ground-contacting wheels mounted to a rear end of the trolley.
Each fork may have a first spacer arm for spacing the first load support from the second load support. The first spacer arm may be of any suitable size, length and construction, it may be adjustable in length, and it may be detachably attachable to the first and/or second load supports. The first spacer arm may have a top wall, a bottom wall and sidewalls. The first spacer arm may, for instance, consist of box steel.
If necessary, a stiffening member may extend through each first spacer arm from the first load support to the second load support.
Each fork may include a second spacer arm extending from the second load support to the rear end of the trolley. This arm may be of any suitable size, length and construction, it may be adjustable in length, and it may be detachably attachable to the second load support. Preferably, the second spacer arm is of similar construction to the first spacer arm and has a top wall, a bottom wall and sidewalls. The second spacer arm may, for instance, consist of box steel. If necessary, a stiffening member may extend through each such arm.
Each fork may have additional spacer arms for spacing additional load supports.
The first and second load supports may be of any suitable shape, size and construction. Preferably, the first and second load supports are of similar construction, and the first and second load supports of one fork are substantially mirror images of the first and second load supports of the other fork.
Preferably, each said load support includes a top wall, a bottom wall having an opening through which a said roller housing extends, and sidewalls and end walls surrounding the roller housing. The top wall, when viewed from above, is preferably octagonal in shape.
Each load support may further have strengthening walls intermediate the top and bottom walls. The top walls of the first and second load supports may be situated above the first and second spacer arms so that the arms are not under load.
Preferably, each said load support further includes a peripheral skirt extending between the top and bottom walls. The skirt may partly or fully surround the sidewalls, end walls and intermediate walls. One or more sections of the skirt may be detachable from the top and bottom walls so that an interior of the load support may be accessed.
The trolley may have a control tower having one or more compartments for containing, for example, controls, displays, a motor or engine, hydraulic components, electronic components, a battery.
The forks may be interconnected in any suitable way. The forks are preferably interconnected at the rear end of the trolley by a connecting frame. The connecting frame may be of any suitable construction. The connecting frame may have frame members extending between the forks and extending parallel to the forks. The frame members may, for example, consist of metal beams screwed and/or welded to one another and to the forks. The connecting frame may further include plates for connecting the control tower to the frame members.
The roller housings may be of any suitable shape, size and construction. If necessary, additional roller housings may be mounted to parts of the forks other than to the load supports.
Preferably, each roller housing has a pitched roof with sidewalls and end walls extending from the roof. The pitched roof provides the roller housing with additional space for rocking.
The roller housings may be pivotally connected to the load supports in any suitable way. Preferably, each said roller housing includes a pin extending through said sidewalls of said roller housing and said sidewalls of the respective load support, and the roof may pivot relative to the pin. In this way, the roller housing may pivot in a rocking motion beneath the top wall of the load support.
Any suitable number of rollers may be mounted within each roller housing. Any suitable type of roller may be used. (The term “roller” as used herein is to be understood as being synonymous with the term “wheel”). The rollers may be mounted in any suitable way. Preferably, each roller housing includes forked roller frames and pins for connecting the rollers to the forked roller frames and for connecting the forked roller frames to the sidewalls of the roller housing.
In one embodiment, forward-, mid- and rearward-pairs of rollers are mounted within each roller housing. In another embodiment, the forward- and rearward-pairs of rollers of each roller housing are substituted for single, more elongate rollers. Such rollers may reduce the amount of damage to the ground over which the trolley travels. In yet another embodiment, each roll housing has one or more additional rollers (idlers) for load sharing purposes. In a preferred embodiment, each roller housing has a single forward roller, a single rearward roller, and a mid-pair of rollers.
The height of the load supports may be adjustable and this may be achieved in any suitable way. Preferably, the load supports are height adjustable by extending and retracting the rollers relative to the roller housings. To this end, each roller housing preferably includes forked roller frames that are pivotally connected to the sidewalls of the roller housing.
The rollers may be extended and retracted by any suitable mechanism. Preferably, each said roller housing includes a hydraulic lifting cylinder for moving the rollers between extended and retracted positions. A housing of the lifting cylinder may be pivotally connected to the roof and a piston of the cylinder may be pivotally connected to a said pin connecting the mid-pair of rollers to their respective forked roller frames.
Preferably, the rollers of a roller housing are pivoted in unison. To this end, each said roller housing may have tie members interconnecting the rollers such that when the mid-pair of rollers pivots, all of the rollers of the roller housing pivot. Each roller housing may further include a pivotable tie support member extending between each said tie member and a sidewall or roof of the roller housing. The tie support members may help prevent the tie members from buckling when under load. Preferably, for load sharing purposes, each roller housing further includes three idlers connected to the tie members.
The trolley may have pressure sensors for confirming that a load has been fully lifted or fully lowered. Such sensors are well known in the art.
In order to load the trolley with cargo, the forks may be positioned between blocks of a pallet carrying cargo with the rollers in the retracted position, and in order to lift the palletised cargo, the rollers may be moved to the extended position, at which time the load supports bear against deckboards of the pallet.
The trolley may have a motor such that the trolley is self-propelling. The motor may be located at the rear end of the trolley. The motor may power the hydraulic lifting cylinders. Alternatively, the trolley may be propelled manually or by any vehicle having sufficient tractive effort and braking capacity. The trolley may be propelled by, for example, a forklift truck or by a hydraulic arm of a crane. The rear end of the trolley may be coupled to the forklift truck or to the hydraulic arm of a crane in any suitable way. For instance, the second spacer arms may have pockets for tynes of a forklift truck at the rear end of the trolley, and/or the trolley may be coupled to a forklift truck with a chain. The forklift truck or crane may power the hydraulic and electrical systems of the trolley.
The trolley may have a steering system that enables the trolley to be steered manually and/or automatically. The steering system may be any suitable type of system known to persons skilled in the art. A preferred steering system is described in the applicant's co-pending application, the entire contents of which are herein incorporated by reference.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings like reference numerals refer to like parts.
FIGS. 1 to 3 show a trolley 1 for transporting palletised cargo. The trolley 1 has two parallel spaced forks 2 each having two load supports 4, 5, a roller housing 6 pivotally connected to each load support 4, 5, and rollers 7, 8, 9, 10, 11, 12, 13 mounted within each roller housing 6. A connecting frame 15 interconnects the forks 2 at a rear end of the trolley 1. A control tower 16, having multiple storage compartments, is connected to the frame 15.
A first pair of load supports 4 is located at a front end of the trolley 1 and a second pair of load supports 5 is located between the first pair 4 and the rear end of the trolley 1. The first 4 and second 5 pairs of load supports are of similar construction, and the load supports 4, 5 of one fork 2 are substantially mirror images of the load supports 4, 5 of the other fork 2. When viewed in plan, each load support 4, 5 is of octagonal appearance.
Referring now chiefly to FIGS. 5 to 9, each second load support 5 has a top wall 20, a bottom wall 21 having an opening 22 through which the roller housing 6 extends, as well as a pair of sidewalls 23, 25 and a pair of end walls 24, 26 that surround the roller housing 6. Further structural walls 27, 28, 29, 30 intermediate the top 20 and bottom walls 21 extend from end walls 24 and 26. The bottom wall 21 has a flat central portion 380, ramp portions 381, 382 extending upwardly from portion 380, and flat portions 383, 384 extending from ramp portions 381 and 382.
The first load supports 4 are shown in detail in
Casings 49, 50 containing spherical bearings 60, 61 are located within openings of sidewalls 23 and 25. Identical casings and spherical bearings are located in sidewalls 23 and 25 of each second load support 5. The openings are clearly shown for load support 5 in
As seen in
Referring now to FIGS. 1 to 3 and 14, a first spacer arm 70 spaces the first load support 4 from the second load support 5. The first spacer arms 70 of each fork 2 are of similar construction, each having a top wall 71, a bottom wall 72 and a pair of sidewalls 73, 74. As seen in
As seen in
A second spacer arm 80 extends from each second load support 5 to the rear end of the trolley 1. This is shown in FIGS. 1 to 3. The second spacer arms 80 are of similar construction to one another and to the first spacer arms 70 in that they each have a top wall 81, a bottom wall 82 and a pair of sidewalls 83, 84. An end portion of each sidewall 83, 84 flares outwardly and locks behind inwardly directed portions of the skirt 31, 32 (not shown), as described earlier for load support 4. As seen in
The top walls 20 of the load supports 4, 5 are slightly raised relative to the top walls 71, 81 of the spacer arms 70, 80 as the load supports 4, 5 bear the load.
The load supports 4, 5 and spacer arms 70, 80 consist of steel plates fitted and welded together. Stainless steel can be used for those parts of the trolley 1 exposed to corrosive agents. The stiffening members 33, 85 each consist of a metal plate welded on its bottom edge to the bottom walls 21, 72, 82.
As seen in
A pair of ground-contacting wheels 100 are connected to forked frames 102 with pins 101, and the forked frames 102 are connected to frame members 92, 96 and 97.
Referring now to
Each roller housing 6 has carbon-steel rollers 7, 8, 9, 10, 11, 12, 13 that may be extended from the housing 6 and partly retracted into the housing 6. Four forked roller frames 120, 121, 122, 123 are pivotally connected to the sidewalls 113, 114 with pins 125, 126, 127 that extend through sleeves 130, 131, 132, 133 of the forked roller frames 120, 121, 122, 123 and further through openings of the sidewalls 113, 114. A forward roller 7 is pinned to forked roller frame 120, a mid-pair of rollers 9, 10 is pinned to forked roller frames 121 and 122 with a single pin 144, and a single rearward roller 13 is pinned to forked roller frame 123.
A pair of tie rods 180, 181 is pinned to each of the forked roller frames 120, 121, 122, 123 so that the rollers 7, 8, 9, 10, 11, 12, 13 pivot in unison. Idler rollers 8, 11 and 12 are pinned to the tie rods 180, 181 and help distribute the load. A pair of pivotable tie rod support members 135, 136 prevent the tie rods 180, 181 from buckling when the rollers 7, 8, 9, 10, 11, 12, 13 have been extended and the trolley 1 is under load. An upper end of each tie rod support member 135, 136 is pinned to a roller housing sidewall 113, 114 and a lower end of each tie rod support member 135, 136 is pinned to a tie rod 180, 181.
Hydraulic lifting cylinders 140 extend and retract the rollers 7, 8, 9, 10, 11, 12, 13 in unison relative to the roller housing 6 such that the trolley 1 may be raised and lowered. A bracket 141 extends from the roof 110 of the roller housing 6 and an end of the lifting cylinder 140 is pivotally mounted thereto with a pin 142. A piston 143 of the lifting cylinder 140 is pivotally connected to pin 144 by way of pin 144 extending through an end ring of the piston 143. When the piston 143 of the lifting cylinder extends 140, the rollers 7, 8, 9, 10, 11, 12, 13 extend some 35 mm (as seen in
The forks 2 are shaped for insertion between the blocks of a single-decked pallet and the load supports 4, 5 can raise the deckboards of the pallet.
The trolley 1 may be propelled by a forklift truck. Tynes of a forklift truck (not shown) may engage openings provided by spacer arms 80 at the rear end of the trolley 1. The forklift truck may be further chained or otherwise secured to the trolley 1 so that the trolley 1 may be pulled in reverse.
The trolley 1 has a steering system for steering both the front and rear roller housings 6, and for steering the front roller housings 6 independently of the rear roller housings 6. The steering system includes: a drive system for actually turning the roller housings 6; distance monitors for monitoring the distance between the trolley 1 and a nearby object, such as a container sidewall; an incremental rotary encoder for monitoring the traveling direction of the trolley 1, the distance traveled by the trolley 1 and the speed of the trolley 1; and, an electronic control system for coordinating and controlling the said components of the steering system.
The drive system is illustrated in
The piston 151 is movable between three positions. In a mid (neutral) position the roller housing 6 is steered straight, as see in
FIGS. 17 to 21 show details of the hydraulic steering cylinder 150. The steering cylinder 150 has a body 160 containing a large bore 161 and a small bore 162 (best seen in
A first port 175 extends to the distal end 165 of large bore 161, a second port 177 extends to the proximal end 166 of small bore 162, and a third port 176 extends to the proximal end 164 of large bore 161. That is, ports 176 and 177 can direct hydraulic fluid to opposite sides of small piston 171, and ports 176 and 175 can direct hydraulic fluid to opposite sides of large floating piston 168.
In order to place the piston 151 in the mid neutral position, hydraulic fluid is directed to the distal end 165 of large bore 161 via port 175. Hydraulic fluid from the proximal end 164 of large bore 161 is directed to reservoir assembly 304 (as shown in
To extend the piston 151 and to steer the trolley 1 to the left, hydraulic fluid within the distal end 165 of bore 161 is directed via port 175 to the reservoir assembly 304, and as the distal end 165 is vacated of hydraulic fluid, the shaft 169 extends 8 mm from within the body 160. In order to return the piston 151 to the mid neutral position, hydraulic fluid is directed to the distal end 165 via port 175, and large floating piston 168 is again forced against shoulder 163.
In order to retract the piston 151 and to steer the trolley 1 to the right, hydraulic fluid is directed to the proximal end 164 of bore 161 via port 176, and hydraulic fluid within the proximal end 166 of small bore 162 is directed to reservoir assembly 304 via port 177. The shaft 169 slides through large floating piston 168 and the piston 151 retracts 8 mm. To return the piston 151 to the mid neutral position, hydraulic fluid is redirected to the proximal end 166 of bore 162 via port 177, hydraulic fluid within the proximal end 164 of bore 161 is directed to reservoir assembly 304 via port 176, and small piston 171 slides against large piston 168.
The wheel 202 may be raised up off the ground when not in use. This may help prevent the encoder 201 from being damaged when the trolley 1 is being moved between locations and not for container loading purposes. A tow bar 205 is pivotally connected to a bracket 206 of rear plate 99 with a pin 207. A pivot arm 208 is connected to the encoder 201 and an end of the pivot arm 208 is pivotally connected to a bracket 209 of frame member 92 with a pin 210. A cable 211 extends through an opening of the rear plate 99 and over frame member 92, and has ends secured to both the tow bar 205 and an upper end of the pivot arm 208. When the tow bar 205 is raised, the pivot arm 208 raises the wheel 202 up off the ground.
Referring now to
The electronic control system enables the steering of the trolley 1 to be carried out automatically or manually. The electronic control system automatically activates the steering cylinders 150 to correct the direction of travel of the trolley 1 when a fork 2 has moved from a pre-set distance from, say, a container sidewall. The pre-set distance is defined by a maximum distance allowable from the container sidewall and a minimum distance allowable from the container sidewall. Since containers are usually of constant width, only one container sidewall need be monitored. For simplicity and cost, the monitors 220, 221 may only be mounted to a single fork 2.
As seen in
The display 260 has a top row 261 of coloured lights (“R” for red, “A” for amber, “G” for green) that illuminate to indicate the position of monitor 220 in relation to the container sidewall. The display 260 has a bottom row 262 of coloured lights which illuminate to indicate the position of monitor 221 in relation to the container sidewall. Buttons 263 illuminate to indicate the direction of manual or automatic steering. A red light will illuminate when a monitor 220, 221 is either at the maximum or minimum distance allowable from a sidewall (and a collision with either sidewall is imminent), and a green light will illuminate when a monitor 220, 221 is at an optimal distance from the sidewall. An amber light will illuminate when a monitor 220, 221 is between the optimal distance and the maximum/minimum distance allowable.
The control panel 500 has press buttons 502 that enable the trolley 1 to be steered manually, as well as press buttons 501 that activate the lifting cylinders 140 to either extend or retract the rollers 7, 8, 9, 10, 11, 12, 13. A selector switch 503 is used to select between manual and automatic steering. A selector switch 504 overrides the rotary encoder 201 and is used to select forward or reverse steering.
Referring now to FIGS. 1 to 3, the control tower 16 has an upper compartment 290 for housing the display 260 and lower compartments 291 for housing a battery, a DC motor driven pump unit powered by the battery, hydraulic equipment (as per
When power is applied to the trolley 1, the pump unit 301 starts under no pressure by directional control 303g freely circulating hydraulic fluid back to the reservoir assembly 304 until directional control 303g is closed by its solenoid. Pressure switches 307, 313 and 317 automatically activate the pump unit 301 to pressurise the accumulator 312 to a preset pressure. When the pressure within the accumulator 312 falls to a predetermined value, then the pump unit 301 is again activated. Hydraulic fluid is stored in the accumulator 312 under pressure in order to eliminate frequent stopping and starting of the pump unit 301 whilst the steering cylinders 150 are in operation.
In order to steer the trolley 1, hydraulic fluid is stored in the accumulator 312 and check valve 316 must be under pressure. Hydraulic fluid is then directed to and drained from select ports 175, 176, 177 of select steering cylinders 150 by way of directional controls 303c, 303d, 303e and 303f using control panel 500, as described earlier. Should fluid pressure fall below the predetermined pressure of pressure switch 313, then the accumulator 312 is re-pressurised as described earlier. The accumulator dump valve 318 must be open for service to release stored fluid pressure.
In order to raise a load, the pump unit 301 starts under no pressure, directional controls 303a and 303g are closed using control panel 500, hydraulic fluid then travels to the lifting cylinders 140 and the rollers 7, 8, 9, 10, 11, 12, 13 extend from the housing 16. The pump unit 301 continues to run until a predetermined pressure is reached (as determined by pressure switch 317), ensuring that the heaviest load is completely raised. In order to lower the load, the pump unit 301 operates until a medium pressure is achieved and directional controls 303g and 303b are opened.
In use, a shipping container is positioned at an end of a loading platform. The container and loading platform are aligned straight by a suitable positioning system. A reflector guard, having a substantially identical profile as an internal sidewall of the container, is positioned on the loading platform in the plane of the internal sidewall. As depicted in
A 2 m single-decked pallet 250 laden with cargo, such as the pallet 250 shown in
The trolley 1 is then driven into the container. If the trolley 1 travels over uneven ground, one or more roller housing 6 will pivot the rollers 7, 8, 9, 10, 11, 12, 13 to maintain contact with the ground and in this way evenly distribute the weight of the cargo. The monitors 220, 221 signal the electronic control system and the electronic control system activates the steering cylinders 150 to steer the roller housings 6 so that each monitor 220, 221 is kept at the pre-set distance from the container sidewall. The position of each monitor 220, 221 relative to the container sidewall is monitored by way of the display 260. Should the monitors 220, 221 have moved too far away from the sidewall, then one or more amber or red lights will appear on the display 260 and the electronic control system will select appropriate directional controls 303 to actuate the steering cylinders 150 and to steer the roller housings 6 towards the container sidewall until the monitors 220, 221 sense that the fork 2 is once again at the pre-set distance. Should a fork 2 have moved too close to the sidewall, then the electronic control system will select appropriate directional controls 303 to actuate the steering cylinders 150 and to steer the roller housings 6 away from the container sidewall until the monitors 220, 221 sense that the fork 2 is once again at the pre-set distance. A red light on the display 260 would indicate to the operator to stop the trolley 1 immediately and to reverse out as a collision with the sidewall is imminent.
With the cargo loaded within the container, the rollers 7, 8, 9, 10, 11, 12, 13 are retracted and the forks 2 are withdrawn from the palletised cargo. The rotary encoder 201 differentiates between forward and reverse directions, and when reversing the trolley 1 out of the container, the roller housings 6 are steered in an opposite direction to that when the trolley 1 is being driven forwards.
The steering system enables a cargo-laden trolley to be accurately and automatically steered within the confines of a cargo container, within about 15 mm of the container sidewalls. The invention is particularly suitable for loads up to about 30 tonnes and 12 m in length. Hence, the present invention overcomes the difficulties with steering a cargo-laden trolley manually within the confines of a shipping container and minimizes the problem of inefficient utilisation of the container.
The pivotable roller housings 6 ensure that the rollers 7, 8, 9, 10, 11, 12, 13 maintain contact with the ground at all times and in this way overcomes the problem of uneven weight distribution of cargo when traveling over uneven ground.
FIGS. 33 to 40 illustrate part of a roller housing 600 and rollers 601, 602, 603, 604, 605, 606 for trolley 1 according to another embodiment of the invention. Each roller housing 600 has a slightly pitched roof 610, a pair of end walls 611, 612 and a pair of sidewalls 613, 614. A pin 616 extends through the sidewalls 613, 614 and into spherical bearings 60, 61 as described earlier such that the roller housing 600 may pivot beneath the top plate 20 of the load support.
Six carbon-steel rollers 601, 602, 603, 604, 605, 606 may be extended from the housing 600 and partly retracted into the housing 600. The rollers 601, 602, 603, 604, 605, 606 extend between opposing sidewalls 701, 702 of a rectangular roller carriage 620.
Two hydraulic rams 630 extend and retract the carriage 620 relative to the housing 600 such that the trolley 1 may be raised and lowered. Rams 630 provide greater clearance between the ground and the housing 600 as compared with lifting cylinder 140 illustrated in FIGS. 10 to 13. A housing of each ram 630 is connected to roof 610 and a piston 632 of each ram 630 is connected to a crosspiece 634 of carriage 620.
Details of the hydraulic rams 630 are shown in
First 670 and second 671 ports for hydraulic fluid extend to bore 661. When the piston 632 is fully retracted, a third port 672 extends between bore 661 and bore 663, and a fourth port 673 extends between bore 663 and bore 665. In order to fully extend piston 632, hydraulic fluid is delivered to bore 661 via port 670, and each of bores 661, 663 and 665 fills with hydraulic fluid. In order to fully retract piston 632, hydraulic fluid is withdrawn from bores 661, 663 and 665 via port 670, after which hydraulic fluid is introduced to bores 661, 663 and 665 via ports 671, 672 and 673.
Due to the low bearing areas of the rams 630 (ie. their inability to withstand high side loads), four sets of vertically extending guides 640, 641, 642 are used for guiding the carriage 620 between the extended and retracted positions. The guides 640, 641, 642 are shown in part in
A hydraulic suspension cylinder 720 is located within each opening 700 above rollers 601, 602, 603, 604, 605 and 606. A piston 721 of cylinder 720 is connected to block 710. Hydraulic lines 722 interconnect all cylinders 720 of the roller housing 600 together in a static condition. When a roller 601, 602, 603, 604, 605, 606 (or rollers) is placed under load, then the respective pistons 721 retract and hydraulic fluid is transferred to cylinders 720 of the other rollers 601, 602, 603, 604, 605, 606 via lines 722 until the pressure is transferred evenly between the rollers 601, 602, 603, 604, 605, 606. Each piston 721 has a maximum stroke of 10 mm. The load-sharing suspension arrangement improves load sharing on all rollers 601, 602, 603, 604, 605, 606 and together with the rocking motion of the roller housing 600 enables the trolley 1 to negotiated greater variations in loading ramp and container floor angles and ground irregularities.
Whilst the above has been given by way of illustrative example of the invention, many modifications and variations may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth.
Claims
1. A transport trolley having:
- at least two interconnected, parallel, spaced forks each having at least two load supports;
- a roller housing pivotally connected to each said load support; and
- rollers mounted within each said roller housing,
- and when the trolley moves over uneven ground, the or each roller housing pivots the rollers to maintain contact with the ground.
2. The transport trolley of claim 1, wherein the trolley has two forks.
3. The transport trolley of claim 1, wherein each said fork has two said load supports.
4. The transport trolley of claim 1, wherein each said load support has a top wall, a bottom wall having an opening through which a said roller housing extends, and sidewalls and end walls surrounding the roller housing.
5. The transport trolley of claim 4, wherein each said load support further has a peripheral skirt extending between the top and bottom walls.
6. The transport trolley of claim 4, wherein each said roller housing has a pitched roof with sidewalls and end walls extending from the roof.
7. The transport trolley of claim 6, wherein each said roller housing includes a pin extending through said sidewalls of said roller housing and said sidewalls of the respective load support, and the roof may pivot relative to the pin.
8. The transport trolley of claim 7, wherein the load supports are height adjustable by extending and retracting the rollers relative to the roller housings.
9. The transport trolley of claim 8, wherein each said roller housing has a hydraulic lifting cylinder for moving the rollers between extended and retracted positions.
10. The transport trolley of claim 9, wherein each said roller housing has forked roller frames and pins for connecting the rollers to the forked roller frames and for pivotally connecting the forked roller frames to said pair of sidewalls of the roller housing.
11. The transport trolley of claim 10, wherein each said roller housing has a single forward roller, a single rearward roller, and a mid-pair of rollers.
12. The transport trolley of claim 11, wherein each said roller housing has tie members interconnecting the rollers such that when the mid-pair of rollers pivots, all of the rollers of the roller housing pivot.
13. The transport trolley of claim 12, wherein each said roller housing further has a pivotable tie support member extending between each said tie member and a sidewall or roof of the roller housing.
14. The transport trolley of claim 12, wherein a housing of the lifting cylinder is pivotally connected to the roof and a piston of the lifting cylinder is pivotally connected to a said pin connecting the mid-pair of rollers to their respective forked roller frames.
15. The transport trolley of claim 12, wherein each said roller housing further has three idlers connected to the tie members with pins.
16. The transport trolley of claim 1, wherein said forks are interconnected at a rear end of the trolley by a connecting frame.
17. The transport trolley of claim 6, wherein a first said load support is located at a forward region of each said fork and a second said load support is located at a central region of each said fork, and the trolley further has one or more wheels mounted to the rear end of the trolley.
18. The transport trolley of claim 17, wherein each said fork has a first spacer arm for spacing the first load support from the second load support.
19. The transport trolley of claim 18, wherein each said fork has a second spacer arm extending from each said second load support to the rear end of the trolley.
20. The transport trolley of claim 19, wherein each said fork has a stiffening member extending within each said spacer arm.
21. The transport trolley of claim 19, wherein said second spacer arms have pockets for tynes of a forklift truck at the rear end of the trolley.
22. The transport trolley of claim 2, wherein one said fork is substantially a mirror image of the other said fork.
Type: Application
Filed: Aug 11, 2004
Publication Date: Feb 24, 2005
Applicant: Tynecat Technologies Pty. Ltd. (Banyo)
Inventors: Bernd Raetze (Bridgeman Downs), Douglas Mayes (Bridgeman Downs), Robert Ellis (Potts Point), Norman Mathers (Bridgeman Downs)
Application Number: 10/916,816