GB2253830A - Material handling vehicle - Google Patents

Abstract

A vehicle for materials handling has a telescopic boom 60 pivotally mounted on transversely spaced supports 71, 72 for elevation by rams 73, 74. The supports 71, 72 and rams 73, 74 are disposed behind a driver location 41 as is the vehicle engine 52. The boom 60 extends fore/aft centrally of the vehicle and to its front end is attached a pair of transversely spaced arms 80, 81 on which is pivotally mounted at 84 a carriage 85 for forks 90, 91 (or other materials handling attachment). The forks 90, 91 can be raised or lowered on the carriage 85 by rams 86 without simultaneous movement of the boom 60. Rams 87, 88 control pivotal movement of the carriage relative to the arms 80, 81 dependent upon the elevation of the boom. The disposition of the supports 71, 72, engine 52, boom 60 and arms 80, 81 permits efficient driver visibility from the location 41. <IMAGE>

Description

TITLE "Improvements in or relating to vehicles for materials handling" TECHNICAL FIELD & BACKGROUND ART This invention concerns vehicles for materials handling and in particular vehicles having a telescopic boom pivotally attached to the vehicle and provided with a material handling attachment for movement between a lowermost position adjacent the ground and an elevated position which is a multiple of the height of the vehicle above the vehicle.

Such vehicles are used for materials handling to provide a versatile machine capable of moving materials to great heights compared with that of the vehicle and for moving materials around a site.

In designing such vehicles it is necessary to provide a stable and manageable machine of limited height to facilitate access under low structures, beams and doorways and yet be extendible to considerable heights for handling materials to such heights. Such vehicles must also be provided with a sturdy boom, not subject to distortion and yet not unduly large to avoid unnecessary weight and obscuring the vision of the driver.

Typical vehicles of the type set forth all suffer from one or more disadvantages, and all from that of serious obstruction of the driver's view in one or more directions.

It is an object of the present invention to alleviate the disadvantages of the prior designs whilst preserving or increasing the benefits of such vehicles.

STATEMENT OF INVENTION & ADVANTAGES According to the present invention there is provided a vehicle for materials handling having a telescopic boom pivotally mounted on a support disposed towards the rear of the vehicle for elevation by ram means, said boom extending forwardly of the pivot and provided with a materials handling attachment at its forward end adapted to move between a lowermost position located at or below ground level and an uppermost position which is a multiple of the height of the vehicle above the vehicle, a driver location on the vehicle, and below the lowermost position of the boom whereby the boom does not impede the driver's view, an engine disposed to the rear of the vehicle so as not to impede the driver's view forwardly and to the side of the vehicle characterised in that the materials handling attachment is connected to the boom by a pair of arms disposed on either side of the vehicle and providing space therebetween for rendering the attachmednt visible from the driver's location.

The driver location is preferably substantially central of the vehicle and directly beneath the boom in the lowermost position thereof although it may of course be disposed fore, aft or to either side of the central location.

Preferably the boom support is provided by a pair of spaced supports disposed behind the driver location, the space between said supports providing rearward visibility from the driver location.

In a preferred embodiment the engine is mounted below and close to the driver location to enhance rearward visibility over the engine.

Preferably the boom in its lowermost position extends fore and aft centrally of the vehicle and comprises a plurality of telescopically co-operating members. The boom may be provided at the forward end with a transverse bar to which said materials handling attachment is connected by said pair of arms.

Preferably the materials handling attachment is movable relative to the boom without attendant movement of the boom itself.

Further according to the present invention there is provided a vehicle for materials handling having a boom pivotally mounted on a support disposed towards the rear of the vehicle for elevation by ram means, said boom extending forwardly of the pivot and provided with a materials handling attachment at its forward end adapted to move between a lowermost position located at or below ground level and an uppermost position which is a multiple of the height of the vehicle above the vehicle, a driver location disposed on the vehicle, an engine disposed to the rear of the vehicle so as not to impede the driver's view forwardly and to the side of the vehicle characterised in that the materials handling attachment is connected to the boom by a connecting device being sufficiently large to cause the boom to be disposed above the driver's location when the materials handling attachment is at or adjacent ground level whereby the boom does not impede the driver's view, and wherein the connecting device incorporates a movable carriage on which the materials handling attachment is located whereby the attachment can be moved without simultaneous movement of the boom.

By this latter aspect of the invention the materials handling attachment can for example be raised and lowered without moving the boom. This will enable the driver to raise loads off the ground and move the vehicle without moving the boom. It also facilitates handling of materials and permits easy placing of loads onto locations without the accompanying momentum of the whole boom. This is particularly important when the boom is extended.

The use of a carriage for the attachment also enables the structure of the connecting device by which the attachment is coupled to the boom to be correspondingly shorter. Thus the connecting device can have a fixed length portion which is shorter than corresponding designs available until now. The movable carriage effectively enables the operator to extend the length of the connecting device to that corresponding to other designs, but again without movement of the boom.

DRAWINGS One embodiment of a vehicle constructed in accordance with the present invention will now be described, by way of example only, with reference to the accompanying illustrative drawings in which: Figure 1 is a side elevation of the vehicle; Figure 2 is a plan view of the vehicle of Figure 1; Figure 3 is a front elevation of the vehicle; Figure 4 is a rear elevation of the vehicle; Figure 5 is a perspective view of the vehicle; Figure 6 is a diagrammatic side elevation of the vehicle of illustrating the range of movement of its materials handling attachment; Figures 7 to 10 are diagrammatic views of four prior known designs of material handling vehicles, and Figures Ila to llc are diagrammatic views of the vehicle of Figures 1 to 6 for comparison with Figures 7 to 10.

DETAILED DESCRIPTION OF DRAWINGS Referring to Figures 1 to 5, a vehicle according to the present invention comprises a rear set of wheels 20, 21 which are pivotally mounted on axles 24, 25 whereby the wheels can be both driven and pivoted for steering.

The vehicle is also provided with a front pair of wheels 30, 31 pivotally mounted on axles 34, 35 whereby these wheels are also both driven and available for steering.

A driver location is indicated by numeral 40 indicating the eye level of a typical driver, the location being provided by a seat 41 mounted within a cab 42. It will be seen that the driver location is disposed centrally of the vehicle with the driver seat 41 essentially on the centre line both in the fore and aft direction and in the side-to-side direction of the vehicle being the optimum location for all-round visibility and control. However, the driver location may of course be disposed fore or aft or on either side of the centre of the vehicle.

Disposed behind the driver location is an engine disposed within an engine cover 51, the cooling system being shown generally in the region 52 and the transmission being shown generally in the region 53. The cooling system could be located elsewhere on the vehicle thus enabling a yet shorter and lower engine cover to be used.

Disposed above the driver's cab 42 centrally of the vehicle and extending from end to end in its lowermost position as shown in the drawings is a three piece telescopic boom 60 comprising a substantially rectangular cross section outer boom 61 having telescopically disposed therein two inner booms 62 and 62a (the innermost of which is shown at 62).

The boom 60 is pivotally mounted for elevating on a tower 70 provided by a pair of spaced supports 71, 72 fixed to the chassis of the vehicle and extending upwardly behind the driver's location and terminating at a position above the driver's cab and substantially over the axis of the axles 24, 25 (see Figure 2). Rams 73, 74 disposed on either side of the outer boom 61 have upper ends which are pivotally attached at axis 75 to the outer boom 61 and lower ends which are pivotally attached to the vehicle chassis at the base of the support tower 70. Operation of the rams 73, 74 will act to elevate the boom 60 from the lowermost position shown in Figures 1 to 5 (where typically the boom is generally horizontal) to an elevated position in which the boom pivots on the tower 70 in the manner shown diagrammatically in Figure 6.

Mounted on the projecting end of inner boom 62 are support plates 80, 81 the plates 80, 81 being rigidly connected to the boom 62 by cross member 83.

The supports 80, 81 extend downwardly from the inner boom 62 (generally at right angles to the boom 60) and at their lower ends are provided with a pivot 84 to which a fork carriage 85 is pivotally mounted. Slidably mounted within the fork carriage 85 is a pair of forks 90, 91 extending outwardly from the fork carriage 85 and adapted to slide within the carriage from the retracted position shown in full lines and denoted by 90a in Figure 1 to the extended position shown in broken lines at 90b in that Figure. Rams indicated at 86 on either side of the fork carriage 85 effect unified movement of the forks 90, 91 within the carriage.

Rams 87, 88 disposed on either side of the support arms 80, 81 and pivotally connected between the support arms 80, 81 and the fork carriage 85 effect pivotal movement of the fork carriage 85 and thus of the forks 90, 91 about the pivot 84.

In operation the vehicle can be driven by either or both pairs of wheels and can be steered by either or both pairs of wheels. Extreme manoeuvrability and traction is provided.

With the boom 60 in its lowermost position as shown in Figures 1 to 5 and as shown in full lines in Figure 6 the boom can be extended by operation of internal rams (not shown) in known manner to extend the telescopic members 61, 62 and 62a from the retracted position shown in Figures 1 to 5 and in full lines in Figure 6 to extended positions, for example shown at (i) and (ii) in Figure 6.

Additionally, by operation of the rams 73, 74 the boom 60 can be pivoted on the tower 70 to elevate the boom from the lowermost position shown in full lines in Figures 1 to 6 to elevated positions, for example shown at (iii), (iv) and (v) in Figure 6. The elevation shown at (iii) is achieved without extension of the telescopic booms but the additional height shown at (iv) and (v) is achieved by both pivoting the boom about pivot 63 and by operating the internal rams (not shown).

As the boom 60 is elevated and pivoted on the tower 70, the forks 90, 91 are maintained in a horizontal position by operation of the rams 87, 88 which cause the fork carriage 85 to tilt about pivot 84 and thus maintain a horizontal disposition for forks 90, 91 at every elevation of the boom 60. The horizontal positioning of the forks 90, 91 may be controlled automatically by use of a set of slave rams 78 and 79 coupled between the rear of the boom 61 and the tower 70. The slave rams 78, 79 extend or retract in response to pivotal displacement of the boom.

These rams are hydraulically linked to the set of rams 87 and 88 so that fluid flow between the two sets of rams causes the rams 87 and 88 to extend or retract as appropriate to maintain the forks horizontal during pivotal movement of the boom.

It will be seen from Figure 6 that the vehicle is provided with good "outreach" being the distance ahead of the front wheels that the forks can be extended and has a good lift height, that is the height to which the forks can be elevated above the ground.

Despite the good outreach and lift height available with this vehicle, the overall height of the vehicle with the boom 60 in its lowermost position is still remarkably low and may be such as to permit the vehicle to operate below low structures and through doorways on typical operating sites.

By disposing the boom 60 above the operators cab there is no obstruction of the driver's view either side of the cab as there would be in such vehicles where the boom 60 is disposed beside the cab and the cab is disposed to one side of the vehicle. Furthermore, with the cab 42 being centrally located both fore and aft of the vehicle and side to side of the vehicle the best visibility is provided for the driver in all directions.

By mounting the forks on support arms 80, 81 which are spaced apart across the support bar 83 the driver is able to see between those support arms 80 and thus able to see the forks 90, 91 without difficulty. In previous vehicles of this nature a single support structure depending from the boom 60 causes problems with visibility for the driver who is unable to see the forks and thus unable to load the vehicle or manoeuvre it with safety.

By mounting the boom 60 on the spaced supports providing the tower 70, the driver is able to see to either side of and between the tower support members 71, 72 and thus adequate vision is provided to the rear of the vehicle.

By mounting the driver's location relatively high in the vehicle and ensuring that there is no engine ahead of the driver to obscure his vision he is able to see to the ground immediately in front of the vehicle and able to see the forks 90, 91 even in their lowermost position.

By mounting the engine 50 low on the vehicle the driver is able to see over the engine cover at the centre point of the vehicle and is in any event able to see on either side of the engine cover to give adequate visibility to the rear of the vehicle.

With the vehicle according to the present invention, far superior visibility is provided for the driver compared with any similar vehicle presently available or previously proposed. Visibility in all directions is excellent providing increased safety during motion of the vehicle and facilitating use of the forks when the driver is loading and moving materials. Safer and faster handling is thus facilitated.

A further particularly beneficial aspect of the present vehicle is the provision of the carriage 85 by which the forks 90, 91 can be moved without accompanying movement of the boom 60. By moving the forks 90, 91 from the position 90a shown in Figure 1 to the broken line position shown at 90b in Figure 1, considerable benefits are achieved. For example and typically, 500 mm of upward movement from ground level to travelling height can be achieved for the forks without lifting the boom. Thus the boom height can be maintained in its lowermost position (typically below 3 metres) thus facilitating movement under low structures and through doorways.

Overall height between the forks and the top of the boom can be reduced compared with those structures in which the forks are fixed and unable to move on a carriage.

The provision of the fork carriage enables the driver to move the load when placed on those forks upwardly and downwardly without consequential movement of the boom, thus facilitating movement with less inertia providing greater control and stability particularly when those manoeuvres are being conducted with the telescopic boom at its extended position when the vehicle will be at its most unstable. Heavy contact and impact between the load and any receiving surface can be minimised by using the fork carriage rather than movement of the boom in the final movement of any material handling.

Thus, the fork carriage can be used to lower the load the last 500 mm or so under controlled vertical movement thus avoiding the movement of the full boom and avoiding the heavy impact that may otherwise result from the inertia or momentum of the moving boom. With the fork carriage, lift height is also increased by the amount of the fork lift provided by the carriage.

The benefits of the fork carriage are achieved at relatively low cost and low weight being provided simply by the rams 86 mounted on the carriage and appropriate slideways or tracks for the forks to be displaceable relative to the carriage 85.

Referring to Figures 7 to 11 there is shown in Figures 7 to 10 diagrammatic views of prior designs of materials handling vehicles and in Figures ll(a) - (c) diagrammatic views of the vehicle of the present invention for the purposes of comparison of the degree of visibility available to the driver of each vehicle. To facilitate comparison like reference numerals have been used for like parts with the prefix distinguishing the various embodiments.

Referring to Figure 7, there is shown a prior design of material handling vehicle 110 having a pair of rear wheels 120, 121, a pair of front wheels 130, 131, a driver location with eye level denoted at 140, an engine 150 situated forward of the driver, a telescopic boom 160 pivoted to supports 170, 171 and provided with a material handling attachment 190 connected to the boom 160 by an arm 180.

"Blind spots" or spaces where driver visibility is seriously impaired are illustrated by shaded areas. Views forward of the driver location are seriously impaired by the engine 150, the whole of the space immediately in front of the vehicle is out of sight of the driver. This presents particular difficulties for loading the attachment 190 and for travelling with the attachment in the lower positions.

The single boom 160 also presents a serious obstruction to the driver since in its lowered position it extends below the horizontal and below the level of the driver's eyes so that forward vision is seriously restricted.

Referring to Figure 8 there is shown another vehicle 210 having a boom 260 mounted low on the vehicle to pass alongside the driver's location 240 which is offset from the centre line of the vehicle and not centrally located.

This design enables the driver to see the lowered attachment 290 even in its lowermost positions but only part of that attachment is visible.

Serious obstruction of the driver's visibility arises because the boom 260 passes beside the driver's location, level with the driver's eyes. Thus, all visibility to the side of the vehicle on which the boom is disposed is virtually blocked. Good visibility is available to the other side, and forwardly and rearwardly but only down one side of the vehicle. For loading and for travelling with the boom in a low position there is serious obstruction for the driver to cope with. The design facilitates the provision of a vehicle of very low overall height but with serious visibility problems.

In Figure 9 there is shown a vehicle in which a pair of booms 360, 361 pass either side of the driver's location 340. Again, this design facilitates low overall height and the attachment 390 can be seen between the arms 380, 381. However, serious obstruction arises either side of the driver since the booms 360, 361 obscure visibility in both directions. Compared with the design of Figure 7 more of the attachment 390 can be seen, the driver has a larger and more comfortable cab, the visibility from a central location is better than the offset location of Figure 8 when the boom is elevated, but the visibility with the boom in the lower positions is far worse.

In Figure 10 there is shown a vehicle having a central boom 460 on a single central support 470 and having a single arm 480 supporting the attachment 490. The engine 450 is located behind the driver location 440 but is high.

Visibility for the driver is impaired in both the forward and rearward directions by the central arm 480 and the central support 470 respectively. Furthermore, visibility below the level of the driver to the rear of the vehicle is impaired by the high engine.

Figure 11 is a diagrammatic illustration of the vehicle of the present invention in which the blind spots are seen to be reduced drastically compared with the prior proposals of Figures 7 to 10. By supporting the forks 90 and 91 on a pair of spaced arms 80, 81, forward vision is facilitated. The driver can see virtually the whole of the fork attachment in all positions. By placing the boom 60 above the driver's eye level 40 there is no impairment of his vision to either side. By avoiding an inclination of the boom substantially below the horizontal even in its lowermost position, the diver 'S view forwardly is not impaired, even with a single boom.

By mounting the boom on a pair of supports 70, 71 the driver's visibility rearwardly is improved. He can see between the supports as well as to either side of them.

The only blind spots are indicated by references A B C D E.

With the vehicle structure according to the present invention, a vehicle is provided having the benefits of good reach, a relatively low overall height and yet excellent visibility for the driver in every direction, a facility not known or available in any existing design of such vehicles.

The benefits of the present invention can be achieved without using the vehicle specifically as described above with reference to Figures 1 to 5. For example, the vehicle could be provided with only two wheel drive rather than the four wheel drive described. Similarly, the vehicle could have two wheel steer rather than four wheel steer.

The gearbox of the vehicle could be replaced by hydraulic pump transmission and hydraulic motor driving axles through transverse gear casing.

The axles could be replaced by hydraulic hub motors driven by hydraulic pumps.

The telescopic boom, although described as having a three piece structure could be provided with further telescopic members or even be of a two piece structure.

Although described as a single boom structure extending down the centre line of the vehicle, the boom 60 could be replaced by a pair of such booms extending parallel one to the other and spaced across the vehicle.

The actual location of the pivot between the boom 60 and the tower 70 may be in line with the boom or may be above or below general line of the boom 60.

The support arms 80 and 81 could be attached directly to the inner boom 62 and need not be connected via the transverse member 83.

Instead of rams 86 to operate the fork carriage 85, such movement could be achieved by a chain or wire rope drive or by a hydraulic motor. Furthermore, the location and disposition of the drive need not be as illustrated.

The boom support tower 70 need not be disposed and located as illustrated in drawings 1 to 5 but could of course be provided by members differently shaped and differently positioned, e.g. in a more vertical disposition or mounted from a point more closely adjacent the rear wheel or even behind those wheels.

The front axle of the machine may have "sway control" or "frame levelling" by which the front axle may oscillate by means of cylinders attached to the chassis to allow the cab to be set vertically even if the tyres are on uneven or unlevel ground.

Stabiliser legs (69 in Figures 1, 2 and 5) may be fitted on the corners of the vehicle and these can be used to stabilise the vehicle by contact with the ground when in static use.

Other obvious variations may be employed such as different sized tyres, use of twin wheels rather than single wheels on each axle, the use of different shaped cabs, seats, engine covers and the like, none of which are critical to the operation of the vehicle.

In place of the forks described above, any appropriate materials heandling attachment could be used such, for example, as a loading platform, a bucket, a crane hoist or hook, cage or any known device.

With vehicles according to the present invention, far superior visibility is provided in every direction and thus greater safety and easier operation is provided giving a greatly improved vehicle compared with anything yet proposed or in use.

Claims (21)

1. A vehicle for materials handling having a telescopic boom pivotally mounted on a support disposed towards the rear of the vehicle for elevation by ram means, said boom extending forwardly of the pivot and provided with a materials handling attachment at its forward end adapted to move between a lowermost position located at or below ground level and an uppermost position which is a multiple of the height of the vehicle above the vehicle, a driver location on the vehicle, and below the lowermost position of the boom whereby the boom does not impede the driver's view, an engine disposed to the rear of the vehicle so as not to impede the driver's view forwardly and to the side of the vehicle characterised in that the materials handling attachment is connected to the boom by a pair of arms disposed on either side of the vehicle and providing space therebetween for rendering the attachment visible from the driver's location.

2. A vehicle as claimed in claim 1 in which the driver location is substantially central of the vehicle.

3. A vehicle as claimed in either claim 1 or claim 2 in which the boom comprises a single telescopic boom structure which in its lowermost position extends fore and aft substantially centrally of the vehicle.

4. A vehicle as claimed in any one of the preceding claims in which the boom support is disposed behind the driver's location.

5. A vehicle as claimed in claim 4 in which the boom support comprises a pair of supports spaced transversely of the vehicle, the space between said supports providing rearward visibility from the driver's location.

6. A vehicle as claimed in any one of the preceding claims in which the engine is mounted behind, adjacent to, and substantially below the driver location to enhance rearward visibility from the driver location over the engine.

7. A vehicle as claimed in any one of the preceding claims in which the ram means is disposed behind the driver location.

8. A vehicle as claimed in claim 7 in which the ram means comprises a pair of rams spaced transversely of the vehicle, the space between said rams providing rearward visibility from the driver location.

9. A vehicle as claimed in any one of the preceding claims in which the boom is provided at its forward end with a transverse bar to which said materials handling attachment is connected by said pair of arms.

10. A vehicle as claimed in any one of the preceding claims in which the materials handling attachment is movable relative to the boom without attendant movement of the boom itself.

11. A vehicle as claimed in claim 10 in which the materials handling attachment is located on a carriage which is pivotally connected to said pair of arms and wherein the materials handling attachment is movable relative to the carriage.

12. A vehicle as claimed in claim 11 in which means is provided for controlling the pivotal movement of the carriage relative to the pair of arms dependent upon the elevation of the boom.

13. A vehicle as claimed in either claim 11 or claim 12 and comprising means reacting between the materials handling attachment and the carriage for raising and lowering the said attachment relative to the carriage.

14. A vehicle as claimed in any one of claims 11 to 13 in which the carriage is pivotally connected to bottom ends of said pair of arms.

15. A vehicle as claimed in any one of claims 11 to 14 in which the carriage comprises a frame having two transversely spaced and upstanding frame members located, one each, adjacent to the pair of arms and pivotally connected thereto at bottom ends of those frame members.

16. A vehicle as claimed in any one of the preceding claims in which the materials handling attachment comprises forks, a loading platform, a bucket, a crane hoist, a hook or a cage.

17. A vehicle for materials handling having a boom pivotally mounted on a support disposed towards the rear of the vehicle for elevation by ram means, said boom extending forwardly of the pivot and provided with a materials handling attachment at its forward end adapted to move between a lowermost position located at or below ground level and an uppermost position which is a multiple of the height of the vehicle above the vehicle, a driver location disposed on the vehicle, an engine disposed to the rear of the vehicle so as not to impede the driver 1 view forwardly and to the side of the vehicle characterised in that the materials handling attachment is connected to the boom by a connecting device being sufficiently large to cause the boom to be disposed above the driver's location when the materials handling attachment is at or adjacent ground level whereby the boom does not impede the driver's view, and wherein the connecting device incorporates a movable carriage on which the materials handling attachment is located whereby the attachment can be moved without simultaneous movement of the boom.

18. A vehicle as claimed in claim 17 in which the connecting device comprises a pair of transversely spaced arms connected to the forward end of the boom and extending downwardly therefrom with the boom in its lowermost position; the carriage is pivotally connected to said pair of arms, and means is provided which reacts between the materials handling attachment and the carriage for raising and lowering the said attachment relative to the carriage.

19. A vehicle as claimed in claim 18 and comprising means for controlling the pivotal movement of the carriage relative to the pair of arms dependent upon the elevation of the boom.

20. A vehicle as claimed in either claim 18 or claim 19 in which the carriage comprises a frame having two transversely spaced and upstanding frame members located, one each adjacent to the pair of arms and pivotally connected thereto at bottom ends of those frame members.

21. A vehicle for materials handling substantially as herein described with reference to Figures 1 to 6 and lla to llc of the accompanying illustrative drawings.