GB1580796A

GB1580796A - Vehicle weight transfer mechanism

Info

Publication number: GB1580796A
Application number: GB525476A
Authority: GB
Original assignee: McConnel Ltd
Current assignee: McConnel Ltd
Priority date: 1976-02-11
Filing date: 1976-02-11
Publication date: 1980-12-03

Description

(54) VEHICLE WEIGHT TRANSFER MECHANISM (71) We, F. W. McCONNEL LItMI- TED, a British Company Of Temeside Works, Ludlow, Salop, SY8 1JL, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it lis to be performed, to be yicularly desbribed in and by the following statement:- This invention relates to a weight transfer mechanism for use with a combination of a machine such as a digger, and a towing vehicle, such as a tractor. The invention is particularly applicable to such an arrangement in which lifting means on rhe machine or vehicle are operated to lift the machine relative to the vehicle.

With such an arrangement of towing vehicle and raacin'e, a danger has been found to exist due to the possibility of an operative on the machine, who usually has his back to the vehicle, raising the machine relative to the vehicle and being crushed against an adjacent part of the vehicle, such as a cab.

An object of the invention is to provide a weight transfer mechanism in which the aforesaid danger is minimised or avoided.

According to the invention, there is provided a weight transfer mechanism comprising a lifting device, a weight transfer member adapted to Ibe operatively assoaiated with the lifting device and to be supported for generally vertical pivotal movement with respect to the vehicle, first abutment means on said member, and second abutment means on the vehicle, the arrangement being such that with the machine connected to the member and said abutments in engagement to prevent relative lifting between the machine and vehicle, operation of the lifting means causes the machine and vehicle to be lifted together as a unit through the intermediary od said member.

When the invention is applied to a vehicle having a three-point linkage, it is very con- venient to use at least one, and usually both, of the lower generally horizontal links of this linkage as the abutment means so that the lifting force is applied to the vehicle through the link or links.

The weight transfer member is preferably supported on an axle of the vehicle, usually at the front thereof, and extends to a location adjacent to and conveniently beyond an axle of the opposite end of the vehicle for coupling to the lifting device. This arrangement enables a tlifiing means associated with the machine to be used as the lifting device, which means usually compasses one or more rams.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic side view of one form of weight transfer mechanism of the invention installed in a vehicle; Figure 2 is a plan view of the mechanism ofFigure 1 Figure 3 is a side view of an alternative form of the mechanism of the invention, and Figure 4 is a diagrammatic plan view of a further alternative form of the mechanism of the invention.

Referring to Figure 1 of the drawings, this shows the mechanism of rhe invention applied to a vehicle in the form of a tractor, of which the front and rear pairs of wheels are represented respectively at 1 and 2 and the front and rear axles respectively at 3 and 4.

The weight transfer mechanism includes a pair of lifting devices shown as hydraulic rams 5 secured at either end of a cross-member 6 of a machine (not shown) to be towed by the tractor. A pair of weight transfer members are provided in the form of beams 7 extending longitudinally of the tractor and converging towards their forward ends where they are supported by chain loops 8 slung over the front axle 3 so as to afford a degree of pivotal movement to the beams lin a generally vertical plane. This arrangement is simple and readily adaptable to a variety of different shapes and sizes of vehicle, such adaptability being further increased Iby making each beam 7 in two tele scopically interengaged parts 7a and 7b so that their lengths may readily be varied and locked in desired positions by inserting a pin 9 through a selected pair of a number of pairs of holes in known manner.

The beams 7 are secured to the cross-mem ber 6 by means of brackets 6a. Each bracket has an outwardly projecting portion 6b secured as Iby welding, to an end of one of the beams 7, and a bifurcated depending portion 6c with which forms a connection by means of a bell joint 6d a lug 6e on the crossrnenaber 6. A bi f;urcated upper portion of each bracket receives a further ball joint lila forming a pivotal con neciion with a respective one of a pair of lower links lii of a standard three-point linkage of the tractor, the upper link of which is re,presented at 12. The forward ends of the links 11 are pivoly connected to the tractor by bell joints 13 in knnnnt manner.

A arossWbar 14 underlying and spaced from the links 111 extends transvetsely of and interconnects the beam 7, and in this embodiment constitutes the abutment means of the beams, although lit will be appreciated that, in a differ- ent arrangement, the upper surface of the beams may be the abutment means, as in Figure 4 bor example. Abutment pads or other adjustment means such as screws may be interposed between the intersecting portions of the beams and cross-bar, enabling the spacing between the cross-bar and links 11 to be adjusted for different thicknesses of link, depending upon the type of tractor to which the mechanism is fitted. The crossbar itself may also be adjustable in length.

When it is desired to transfer the weight supported by the wheels 2 to the rams 5, which form supporting legs when extended, the rams are pressurised to exert a lift against the groond. The initial effect of this is to take up the spacing between the cross-bar 14 and links 11, whereupon the links and beams 7 are effectively locked together so that further lift exerted Iby the rams is applied via the links to the rear axle 4 of the tractor to raise the rear wheels Off the ground and thus transfer a portion of the tractor weight to the rams 5.

This locking effect provides an important safety aspect in 'that once the beams 14 and links lii come into engagement during lifting, the tractor and towed machine are effectively locked together and lifted as a unit and there is therefore no possibility of the machine tilting rearwardly towards the tractor with possible danger to the driver of the machine, as is the case with some conventional arrangements.

Figure 3 illustrates an alternative embodiment of the weight transfer mechanism of the invention in which the basic arrangement of beams 7 and links 11 is similar to that of Fig- ure 11, but in which the rams 5 are replaced by legs 50 of adjustable length. In this arrangement, lifting of the implement is effected by means of the tractor three-point linkage, which raises the legs, the length of which is adjusted as nearly as possible to bring them to nest on the ground. The leg adjustment means may conveniently be a pin and slot arrangement indicated at 51.

lowering the implement by way of rhe threepoint linkage to bring the legs onto the ground increases the clearance between the arosswbar 114 and links 11, and in order to enable this clearance to be taken up, means 52 are disposed between each of the beams 7 and the cross-bar 14. Such means may be of any convenient form, either mechanically or fluid-pressure operated, but as shown it con silts of a bolt 53 screwed into a threaded bore in the crossbar and rotatable in a sleeve 54 in the associated beam 7. When clearance has been taken up between the links 11 and cross- bar '14 by operation of the means 52, the crossbar and beams are effectively locked together as before, providing the aforesaid safety feature.

A further alternative form of the mechanism of the invention is shown in Figure 4, in which the crossbar 14 is dispensed with and the beams 7 extend parallel to each other beneath the links 111 enabling lift to be exerted directly by the beams on 'the links. The rams 5 extend obliquely and generally transversely of the vehicle and are connected to the beams 7 by a rigid V-shaped bracket 15 and pivoted legs 116. The rear ends of the beams 7 are rigidly connected together for stability by a crossmember 17 and this assembly is also connected by pivot pins 10 and lugs 6a to the cross-beam 6 of a machine as ibefore so that the machine is raised with the tractor when the rams 5 are extended. The actor is raised when the beams 7 engage the links 11, as before, upon extension of the rams, the upper surfaces of the beams constituting abutment means in this embodiment. The forward ends of the beams may be rigidly interconnected by a further cross-member 17a wlich, together with the beams 7 and member 17 form a rigid frame which may be fitted in one piece to a tractor implement combination.

Means may also be provided for lifting the front end of the tractor and Figure 4 shows one possible arrangemene for this. The front crossnember 17a is connected by a bracket arrangement 18 to a single hydraulic ramW operated leg 19. It would alternatively be possible to use a pair of wed rams aaing on the ends of the beams 7, either dircctly or via cross-member 17a when present. When the forward ends of the beams are interconnected, the beam assembly may ibe slung from the front axle of the tractor by means of a single chain passing over the axle and attached to the respective beams.

It will Ibe appreciated that, although it is prefelsed to use Ibeams 7 af substantial length as shown, because this miniinises the stroke of ram required to initiate lifting, it would nevertheless be possible to pivot the beams at a location on the tractor nearer to the rams.

Instead of using twin Ibeams 7, it may be possible to use a single preferably generally central beam with a transverse portion at its rear end for engagement with the cross links or one cm more other abutments. It will be understood that means for lifting the forward end d the vehicle can be used with any form of the mechanism of the invention.

The lifting device may be constituted by a fluid operated implement, such as the arm or bracket of a machine carried by the vehicle, the implement being arranged to contact the ground when desired in order to react the force derived from the fluid operation and thus lift the vehicle and machine. The aforesaid safety aspect becomes particularly advantageous in this case in preventing a vehicle operator from raising the machine independently of the vehicle and thus obviating possible danger to the machine operative.

The invention also embraces a machine or implement incorporating the weight transfer mechanism of the invention intended for ating to a towing vehicle, as well as a combination of towing vehicle and machine to be towed incorporating a weight transfer mechanism.

WHAT WE CLAIM IS:- 1. A weight transfer mechanism for a towing vehicle and a machine to be towed, com- prising a lifting device, a weight transfer member adapted to be operatively associated with the lifting device and to be supported for generally vertical pivotal movement with respect to the vehicle, hirst abutment means on said member, and second abutment means on the vehicle, the arrangement being such that with the machine connected to the member and said abutments in engagement to prevent relative lifting between the machine and vehicle, operation of the lifting means causes the machine and vehicle to be lifted together as a unit through the inte & nediary of said member.

2. A mechanism according to Claim 1 wherein the vehicle is equipped with a threepoint linkage and at least one of the lower generally hofizentai links thereof constitutes the abutment means.

3. A mechanism according to Claim 1 or Claim 2 wherein a pair of said members is provided and the members converge towards the front of the vehicle.

4. A mechanism according to any one of the preceding claims wherein the length of each member is adjustable.

5. A mechanism according to any one of Clairns 2 to 4 wherein the members are spaced so as to be outside the lower links and are joined by a csossar which engages the tower links to prevent relative lifting between the vehicle and machine.

6. A mechanism according to any one of Claims 2 to 5, wherein the members carry means for forming pivotal connections both with the lower links and with the machine.

7. A mechanism according to any one of the preceding claims wherein adjustable means are provided for taking up clearance between each member and abutment means.

8. A mechanism according to claim 5, wherein the crossbar is adjustable lin length.

9. A mechanism according to Claim 1 wherein a pair d substantially parallel members is provided, the members being inter connected by a pair of crossbars to form a rigid frame.

10. A mechanism according to Claim 9 wherein the forward cross-bar is provided with a ram for lifting the front wheels of the vehlicle of the gnund.

11. A mechanism according to Claim 9 or Claim 10 wherein respective rams extend obliquely and generally transversely of the vehicle and are aonnected respectively to the members by arms forming pivotal connections with the rams.

12. A weight transfer mechanism s\tstan- tially as hereinbefore described with reference to Figures 1 and 2, Figure 3 or Figure 4 of the accompanying drawings.

~3. A combination of towing vehicles and machine to be towed, the combination incor poraring a weight transfer mechanism accord- ing to any one of the preceding claims, the front ends d the members Ibeing connected to the vehicle and the rear ends of the members being connected to the machine.

14. A combination according to Claim 13 wherein the machine has one or more rams arranged to lift the machine and, via the members, the vehicle.

'15. A combination aoding bo claim 13 wherein the machine has supporting legs adjustable in length and the machine is lifted by means of a three point linkage of the vehicle.

16. A combination of towing vehicle and towed machine substantially as hereinbefore described with reference to Figures 1 and 2, Figure 3 or Figure 4 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. understood that means for lifting the forward end d the vehicle can be used with any form of the mechanism of the invention. The lifting device may be constituted by a fluid operated implement, such as the arm or bracket of a machine carried by the vehicle, the implement being arranged to contact the ground when desired in order to react the force derived from the fluid operation and thus lift the vehicle and machine. The aforesaid safety aspect becomes particularly advantageous in this case in preventing a vehicle operator from raising the machine independently of the vehicle and thus obviating possible danger to the machine operative. The invention also embraces a machine or implement incorporating the weight transfer mechanism of the invention intended for ating to a towing vehicle, as well as a combination of towing vehicle and machine to be towed incorporating a weight transfer mechanism. WHAT WE CLAIM IS:-

1. A weight transfer mechanism for a towing vehicle and a machine to be towed, com- prising a lifting device, a weight transfer member adapted to be operatively associated with the lifting device and to be supported for generally vertical pivotal movement with respect to the vehicle, hirst abutment means on said member, and second abutment means on the vehicle, the arrangement being such that with the machine connected to the member and said abutments in engagement to prevent relative lifting between the machine and vehicle, operation of the lifting means causes the machine and vehicle to be lifted together as a unit through the inte & nediary of said member.

'

15. A combination aoding bo claim 13 wherein the machine has supporting legs adjustable in length and the machine is lifted by means of a three point linkage of the vehicle.