GB2253831A

GB2253831A - Load handling vehicle

Info

Publication number: GB2253831A
Application number: GB9105882A
Authority: GB
Inventors: David Richard Krayem
Original assignee: GCM 600 Ltd
Current assignee: GCM 600 Ltd
Priority date: 1991-03-20
Filing date: 1991-03-20
Publication date: 1992-09-23
Also published as: JPH05124798A; IE914571A1; GB9105882D0; NO914866L; PT100105A; FI915665A0; KR920017882A; FI915665A; NO914866D0; EP0504527A1

Description

I- 2253831

TITLE "A load handling vehicle" TECHNICAL FIELD & BACKGROUND ART

The present invention relates -to a load handling vehicle having a load handling assembly which, usually, will comprise forks or a platform.

In known vehicles of the kind mentioned, the forks or platform extend generally horizontally and forwardly of the vehicle for load carrying purposes. Usually the forks or platform can be raised or lowered on the vehicle to facilitate load handling. The forwardly pr63ecting load carrying part of the vehicle, such as the forks or platform, can add considerably to the overall length of the vehicle and when not in use this projection can be hazardous and inconvenient during manoeuvring or storage of the vehicle. It has hitherto been proposed for the load carrying part to be pivotally mounted on the vehicle so that when such part is not required f or use, it can be pivotted manually to a stored position in which it is accommodated and retained adjacent to the vehicle to reduce the overall vehicle length. However, with heavy duty load handling vehicles, the weight of the pivotally mounted load carrying part may be too great for safe. or acceptable adjustment to its stored position by manual effort and it is an object of the present invention to provide a load handling vehicle which alleviates this difficulty whereby a platform, forks or other load carrying or handling part of the vehicle can be adjusted to a relatively unobtrusive stored position in a convenient and relatively simple manner with negligible manual effort.

STATEMENT OF INVENTION & ADVANTAGES

According to the present in vention there is provided a vehicle having a load handling assembly which assembly comprises a-pivotally mounted carriage; carriage control means for pivotting the carriage between a first condition in which the carriage extends upwardly and a second condition in which the carriage extends forwardly/rearwardly of the vehicle; load carrying means 2 pivotally mounted on the carriage to be pivotal between an operative position in which, with the carriage in its first condition, the load carrying means extends forwardly of the carriage for load carrying purposes and a stored position in which the load carrying means is accommodated unobtrusively on the vehicle, and wherein the assembly is arranged so that pivotal displacement of the load carrying means from its operative to its stored position can be accomplished by abutment of the load carrying means with a ground surface and controlled pivotal movement of the carriage from its first condition to its.second condition so that the load carrying means is caused to be pivotted from its operative position to its stored position in which position it can be secured relative to the carriage and following which securing the carriage can be pivotted to its f irst condition carrying with it the load carrying means in its stored position.

By the present invention the load carrying means of a heavy duty vehicle such as the forks of a fork lift vehicle, the platform of an elevator on a vehicle, or a similarly projecting load carrying part when not in use can be pivotted to a relatively unobtrusive stored position, usually adjacent to the carriage, thereby facilitating vehicle manoeuvring, vehicle storage or removal of a hazard which may otherwise be presented by the load carrying part in its operative position, by power operated and controlled displacement of the carriage. This displacement of the carriage can achieve the required pivotal movement of the load carrying means from its operative position to its stored position during abutment of the load carrying means with the grqund surface on which the vehicle may stand-or with other appropriate surface against which the load carrying means can abut during its relative pivotal displacement with the carriage. This pivotal movement of the load carrying means to its stored condition may be is 3 achieved solely by use of the carriage control means which is conveniently in the f orm of a f luid pressure operated ram. The aforementioned pivotal movement can also be facilitated by appropriate manoeuvring of the vehicle and/or, where the load handling assembly is carried at the front end of a telescopic boom, by appropriate adjustment in the length of the boom.

Usually the carriage will include releasable securing means such as a latch mechanism by which the load carrying means, when in its stored condition, can be temporarily secured relative to the carriage.

Preferably the pivotal mounting of the load carrying means is displaceable relative to the carriage and second control means can be provided by which, when the carriage is in its first condition, the load carrying means can be raised or lowered relative to the carriage for convenience of load handling. The second control means conveniently comprises a fluid pressure operated ram which reacts between the carriage and a displaceable frame part on which the load carrying means is pivotally mounted on the carriage. It will be appreciated that other second control means can be utilised such as a motor driven chain as is conventional f or controlling f ork height in f ork lif t trucks. Desirably with the carriage in its first condition and the load carrying means in its operative position, the second control means is adjustable to displace the load carrying means so that a load carrying part thereof (such as the tines of a fork lift or the load carrying surface of a platform) can be located at a position lower than that of the carriage to facilitate load handling. - h Preferably the load carrying means has a substantially L-shape, one limb of which presents a load carrying part and the other limb providing a shank part which is pivotally connected to the carriage. With the carriage in 4 is its f irst condition and the load carrying means in its operative condition, the load carrying part can extend f orwardly of the vehicle f or load carrying purposes and the shank part can extend upwardly adjacent to the carriage and be pivotally mounted at an upper end thereof to the carriage; when the load carrying means is in its stored condition with the carriage in its first position, the shank part can again extend upwardly adjacent to the carriage while the load carrying part extends rearwardly of the vehicle to remove the hazard presented by the projection of that part forwardly of the vehicle. The aforementioned L- shape of the load carrying means is particularly useful when such means is displaceable relative to the carriage to permit the load carrying part to be lowered to a position lower than that of the carriage when the latter is in its first condition.

DRAWINGS One embodiment of a fork lift 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 whith:- Figure 1 is a perspectve view of the vehicle; Figure 2 is a side elevation of the vehicle, and Figures 3 to 5 each show a side elevation of the load handling assembly of the vehicle and sequentially illustrate the adjustment of its load carrying forks from an operative position to a stored position in which the forks are unobtrusively accommodated on the vehicle.

DETAILED DESCRIPTION OF DRAWINGS

The fork lift vehicle illustrated is for heavy duty load handling and has a body 1 with a-driver cab 2 andis manoeuvrable on driven wheels 3. Extending upwardly from the body 1 and to the rear of the cab 2 are struts 4 on which is pivotally mounted at 5 a telescopic boom 6. The boom 6 extends in the forelaft direction of the vehicle and centrally thereof to overlie the cab 2 and carries at its front end a load handling assembly 7. The boom can be rotated about its pivot 5 f or adjusting the elevation of the assembly 7 by hydraulic rams 8. The extension and contraction of the telescopic sections in the boom 6 to vary the positioning of the assembly 7 inwardly or outwardly relative to the body 1 may be effected by fluid pressure operated rams in a manner well known in the art.

The f ront end of the boom 6 on which the load handling assembly 7 is mounted includes a pair of arms 9 which are spaced widthwise of the vehicle and are usually welded at 10 to the front end telescopic section 6a of the boom to f orm a rigid extension of that section and so that the arms 9 project at right angles to the main length of the boom 6 as shown generally in Figure 2. It is to be appreciated that the structure of the vehicle so f ar described is by way of example only and that many variations are possible in mounting the assembly 7 at the f ront end of a vehicle body on appropriate supports similar to those presented by the arms 9.

The load handling assembly 7 includes'a' carriage 20 in the form of a generally upstanding rectangular frame having opposed sides 21 the lower ends of which are pivotted at 22, one to each of the arms 9 to pivotally mount the carriage 20 on the front end of the boom 6. Pivotal movement of the carriage 20 relative to the arms 9 is controlled by a pair of hydraulic rams 23 which connect one between each arm 9 and the adjacent carriage frame side 21.

With the vehicle standing on a horizontal ground surface 24, the rams 23 will normally retain the carriage 20 at a pivotted position in which the frame of the carriage -is located in a generally vertical plane as shown in Figure 2.

Located within the frame of the carriage 20 and extending between its sides 21 is a crossbar 25. The bar 25 is accommodated within longitudinally extending slots 26 6 of the carriage so that it can be displaced vertically relative to the carriage -frame when that frame is disposed vertically as shown in Figure 2. The crossbar 25 is controlled by hydraulic rams 27 which react between that bar 25 and a base 28 of the frame 20.

The crossbar 25 carries a pair of L-shaped forks 30, one limb of said shape providing a shank 31 and the other limb providing a tine 32. The free end of the shank 31 is mounted by a pivot 33 to a bracket 34 which is carried by the crossbar 35 in the carriage 20 (see Figure 3). In normal use of the load handling assembly as shown in Figure 2, the forks 30 hang from their respective brackets 34 with their shanks 31 vertical and adjacent to the carriage 20 while the tines 32 are presented to extend forwardly of the vehicle for load handling purposes in a manner conventional for fork lifts. The brackets 34 may be slidably mounted on the crossbar 25 so that the spacing between the forks 30 can be adjusted as appropriate for load lifting.

By extension and contraction of the rams 27 it will be appreciated that the consequential displacement of the crossbar 25 relative to the carriage fraifte will raise or lower the tines 32 (as indiqated by the arrow 40 in Figure 3) for convenience of load handling. Preferably when the rams 27 are fully retracted and with the carriage 20 disposed vertically, the tines 32 are disposed at a lower level than the base 28 of the carriage 20 as shown in Figure 3 - again for convenience of load handling.

During normal use of the fork lift and when the boom 6 is elevated, the rams 23 which control pivotal movement of the carriage 20 will be actuated to maintain the carriage 20 yertical - this may, conveniently, be achieved by appropriate displacement of hydraulic fluid between the cylinders 23 and slave cylinders 41 (see Figures 1 and 2) which react between the boom 6 and struts 4 to extend or retract as appropriate in response to changes in elevation 7 of the boom.

The tines 32 when projected for normal fork lift use add considerably to the overall length of the vehicle which may be inconvenient for vehicle storage or manoeuvring and they can also present a hazard. To alleviate these difficulties the load handling assembly 7 is arranged so that the forks 30 can be adjusted to an unobtrusive stored condition and in a manner which will now be described with reference to Figures 3 to 5.

With the tines 32 presented for normal load handling and the carriage 20 disposed vertically,.the forks 30 are lowered to abut the ground surf ace 24 (by either or both actuation of the rams 27 or lowering the boom 6) as shown in Figure 3. The carriage control rams 23 are now extended as the vehicle is moved rearwardly (in the direction of arrow 50 - Figure 3) causing the carriage 20 to rotate about its pivots 22 on the arms 9 and in the direction of arrow 42 (Figure 3) while the forks 30 simultaneously rotate in the direction of arrow 43 about their pivots 33. These pivotal movements in the load handling assembly continue until the carriacje 20 is located substantially horizontally -o extend forwardly/rearwardly of the vehicle and the forks 30 have rotated through approximately 180' so that their shanks 31 are again disposed to lie adjacent to the frame of the carriage 20 as shown in Figure 4. With the forks 30 positioned on the carriage 20 as shown in Figure 4, those f orks may be secured relative to the carriage 20 by a latch mechanism or catch 44 which mechanism is conveniently a fitting carried by the carriage. Following attachment of the latch 44 to the forks, the rams 23 are retracted to, rotate the carriage about its pivots 22 and in the direction of arrow 45 in Figure 4 so that the carriage is again raised into its vertical position and carries with it the forks 30 as shown in Figure 5.As will be seen from Figure 5, the tines 32 8 is are now directed rearwardly of the vehicle to be unobtrusive and in a manner which reduces the overall length of the vehicle and alleviates the hazardous presentation of the tines.

As an alternative or in addition to the vehicle being driven rearwardly to effect pivotal movement of the forks from the position shown in Figure 3 to that shown in Figure 4, such pivotal movement can be achieved (posE. bly without movement of the vehicle) by lowering the forks onto the ground surface 24 as shown in Figure 3 with the telescopic boom 6 in an extended condition and subsequently retracting the boom to provide the same effect as rearward movement of the vehicle.

From the aforegoing it will be appreciated that the forks 30 can be adjusted from their operative position shown in Figure 3 to their stored position shown in Figure 5 solely by use of the power which is available in the vehicle thereby alleviating an operator from attempting to move the forks to their stored position manually.

Furthermore, if the latches 44 are biased to automatically engage with the fork shanks 31 during pivotal movement of the carriage to the position shown in Figure 4, it will be appreciated that the driver of the fork lift vehicle can control the load handling assembly to adopt the stored condition shown in Figure 5 without leaving the cab 2.

9

Claims

1. A vehicle having a load handling assembly which assembly comprises a pivotally mounted carriage; carriage control means for pivotting the carriage between a f irst condition in which the carriage extends upwardly and a second condition in which the carriage extends forwardly/rearwardly of the vehicle; load carrying means pivotally mounted on the carriage to be pivotal between an operative position in which, with the carriage in its first condition, the load carrying means extends forwardly of the carriage for load carrying purposes and a stored position in which the load carrying means is accommodated unobtrusively on the vehicle, and wherein the assembly is arranged so that pivotal displacement of the load carrying means from its operative to its stored position can be accomplished by abutment of the load carrying means with a ground surface and controlled pivotal movement of the carriage from its first condition to its second condition so that the load carrying means is caused to be pivotted from its operative position to its stored position in which position it can be secured relative to tke carriage and following which securing thp carriage can be pivotted to its first condition carrying with it the load carrying means in its stored position.

2. A vehicle as claimed in claim 1 in which the carriage is provided with releasable securing means by which the load carrying means can be temporarily secured relative to the carriage in its stored position.

3. A vehicle as claimed in either claim 1 or claim 2 in which the pivotal mounting of the load carrying means is displaceable, relative to the carriage. and second control means is provided by which, when the carriage is in its first condition, the load carrying means can be raised or lowered relative to the carriage.

4. A vehicle as claimed in claim 3 in which with the is carriage in its first condition, the second control means is adjustable to displace the load carrying means so that a load carrying part thereof can be located at a level lower than that of the carriage.

5. A vehicle as claimed in either claim 3 or claim 4 in which the second control means comprises a fluid pressure operated ram which reacts between the carriage and a relatively displaceable frame part on which the load at- carrying means is pivotted.

6. A vehicle as claimed in any one of the preceding claims in which the carriage is pivotaIly mounted on a pivotally mounted boom that is adjustable in elevation for raising and lowering the load handling assembly and wherein the carriage control means reacts between the boom and the carriage.

7. A vehicle as claimed in claim 6 in which the boom is telescopic and the load handling assembly is located at a front end of said boom.

8. A vehicle as claimed in any one of the preceding claims in which the carriage control means comprises a fluid pressure operated ram.

9. A vehicle as claimed in any one of the preceding claims in which with the carriage in its first condition, the pivotal mounting for the carriage is located at a bottom part thereof.

10. A vehicle as claimed in any one of the preceding claims in which the load carrying means has a substantially L-shape comprising a shank part and the or a load carrying part, and wherein with the carriage in its first condition and the load carrying means in its operative condition, said load carrying part extends forwardly of the vehicle for load carrying purposes and said shank part extends upwardly and is pivotally mounted at an upper end thereof to the carriage. and when the load carrying means is in its stored position with the carriage in its first condition, 11 said shank part extends upwardly and said load carrying part extends rearwardly of the vehicle.

11. A vehicle as claimed in any one of the preceding claims in which the load carrying means comprises forks which, in their operative position and with the carriage in its first condition, present tines for load handling.

12. A vehicle as claimed in any one of claims 1 to 10 in which the load carrying means comprises a platform which in its operative position and with the carriage in its first condition presents a surface for load carrying.

13. A vehicle having a load handling assembly substantially as herein described with reference to the accompanying illustrative drawings.