GB1579797A - Wheeled vehicles - Google Patents

Description

(54) IMPROVEMENTS IN WHEELED VEHICLES (71) I, LESLIE BASIL THWAITES, a British Subject, of Thwaites Engineering Company Limited, Cubbington, Leamington Spa, Warwickshire, CV32 7NQ, hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to wheeled vehicles such as load handling vehicles as used, for example, on building sites. In particular the invention is concerned with a vehicle having a chassis supporting a crane jib for raising and lowering loads. Many vehicles of this kind have been proposed hitherto, one type including a crane jib comprising a telescopically adjustable boom which is pivotally connected to a chassis having a single set of steerable wheels. This particular type of vehicle has been found advantageous in that the boom can conveniently carry lifting forks as well as other load handling attachments. An object of the invention is to provide an improved vehicle having a chassis supporting a crane jib which is particularly, but not exclusively, of the telescopically adjustable boom type.

According to the invention there is provided a vehicle which includes a chassis supported by first and second axles provided with ground wheels, each axle being mounted for pivoting relatively to the chassis frame about a vertical axis intersecting the longitudinal axis of the chassis, steering means for slewing the axles in opposite senses about their respective vertical axes relatively to the chassis, an engine for driving the ground wheels of at least one of the axle assemblies, and a crane jib mounted on the chassis.

Such a chassis provides increased manoeuvrability together with a steering arrangement simpler and more robust than the Ackerman type steering of known crane jib carrying vehicles.

Preferably the jib is of the telescopically adjustable boom type, the longitudinal axis of which is contained in a vertical plane passing through the longitudinal axis of the chassis.

The boom will normally be extendable beyond one end of the chassis and will create a turning moment about the axle nearest the loaded end. Such turning moment obviously reduces the loading on the other axle, the load reduction becoming increasingly noticeable as the boom is loaded. Such load reduction can affect the manoeuvrability of the vehicle and, where the vehicle is driven by the wheels on that axle alone as in known vehicles, loss of traction can result. In order to maintain adequate loading of the axle remote from the load-bearing of the boom, I propose to mount the engine over that axle or beyond the axle in a direction away from the load-bearing end of the boom.

The boom is preferably pivotally connected to the chassis and can be raised or lowered by hydraulic rams.

In order to provide improved traction, I prefer to drive the ground wheels on each axle.

A vehicle in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is an elevation of a preferred form of vehicle in accordance with the invention, Figure 2 is a diagrammatic underplan view of the vehicle shown in Figure 1, and Figure 3 is a diagrammatic end view of the vehicle shown in Figures 1 and 2 looking in the direction of arrow III in Figure 1.

The vehicle has a chassis including two longitudinal members 10 which support turntables 11, 11' carrying respective front and rear axles 12, 13. The axles carry ground wheels 14. The front or rear turntable may support its axle by means defining an axis of pivoting extending longitudinally of the vehicle.

Such an arrangement allows the wheels of that axle to rise and fall relatively to the wheels of the other axle when the vehicle is being driven over uneven ground.

The axles 12, 13 are steered by means of a hydraulic ram 16 extending between one of the chassis members 10 and a mounting plate 17 on the turntable 11. The mounting plate 17 is pivotally connected to a further mounting p ate 18 on the turntable 11' by means of a link 19. It will be understood that turning movement of the turntable 11 will be transmitted to the turntable 11' so that the axles 12, 13 will be slewed simultaneously in opo- site senses. The vertical axes of pivoting V) of the turntables 11, 11' intersect the longitudinal axis (L) of the vehicle as shown in Figure 2.

The rear end of the chassis (the left hand end as viewed in Figures 1 and 2) supports an engine 20, the engine being arranged behind the axle 13 for reasons to be explained hereinafter. The engine drives all four wheels of the vehicle through a twin shaft drive arrangement indicated generally at 21.

Two trunnions 22 project upwardly from the chassis members 10 adjacent the engine 20 and pivotally support one end of a telescopically adjustable boom 23. The boom can be raised or lowered bv means of hydraulic rams 24 carried by the chassis members 10. In its fully elevated and fully extended position, the free end of the boom 23 will preferably lift a load to a position approximately twently one feet above the surface on which the vehicle rests. The maximum reach of the boom can, of course, be varied to suit requirements. When the boom is loaded, a turning moment is created about the axle 12 which reduces the load on the wheels 14 of axle 13. However by positioning the engine 20 over or to the rear of the axle 13 sufficient load on the rear wheels 14 can be maintained so that there is no loss of traction even when the boom is fully laden.

The right hand chassis member 10 (when looking forwardly of the vehicle) supports a cab 30 for a driver. The cab is positioned so that the driver will have all round vision when the boom is lowered which is advantageous when travelling along highways.

The free end of the boom may carry and suitable load carrier such as forks 25. In this case the forks are mounted by means of pivot 26 on a plate 27 which is carried by the boom, thus enabling the forks to be tipped sideways.

Alternatively, of course, the forks could be rigidly mounted on the plate 27.

Instead of forks, the boom could be adapted to carry a hook to be raised or lowered by a cable wound around a drum mounted on the chassis.

Although specific reference has been made to a boom-type jib (which is normally extended by hydraulic means) the chassis may carry any other suitable kind of jib for load-lifting purposes. Also, whilst a fourwheel drive is preferred, a two-wheel drive arrangement may be adequate where the vehicle will not be used on boggy terrain.

WHAT I CLAIM IS: 1. A vehicle which includes a chassis supported by first and second axles provided with ground wheels, each axle being mounted for pivoting relatively to the chassis frame about a vertical axis intersecting the longitudinal axis of the chassis, steering means for slewing the axles in opposite senses about their respective vertical axes relatively to the chassis, an engine for driving the ground wheels of at least one of the axle assemblies, and a crane jib mounted on the chassis.

2. A vehicle according to Claim 1, wherein the jib is of the telescopically add used able boom type, the longitudinal axis of which is contained in a vertical plane passing through the longitudinal axis of the chassis.

3. A vehicle according to Claim 2, wherein the engine is mounted either over the axle which is remote from the loadbearing end of the boom, or beyond that axle in a direction away from the load-bearing end of the boom.

4. A vehicle according to Claim 2 or 3, wherein the boom is pivotally connected to the chassis and can be raised or lowered by hydraulic rams.

5. A vehicle according to any preceding claim, wherein the ground wheels on each axle are driven.

6. A vehicle substantially as herein described, with reference to the accompanying drawings.

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

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. pivoting extending longitudinally of the vehicle. Such an arrangement allows the wheels of that axle to rise and fall relatively to the wheels of the other axle when the vehicle is being driven over uneven ground. The axles 12, 13 are steered by means of a hydraulic ram 16 extending between one of the chassis members 10 and a mounting plate 17 on the turntable 11. The mounting plate 17 is pivotally connected to a further mounting p ate 18 on the turntable 11' by means of a link 19. It will be understood that turning movement of the turntable 11 will be transmitted to the turntable 11' so that the axles 12, 13 will be slewed simultaneously in opo- site senses. The vertical axes of pivoting V) of the turntables 11, 11' intersect the longitudinal axis (L) of the vehicle as shown in Figure 2. The rear end of the chassis (the left hand end as viewed in Figures 1 and 2) supports an engine 20, the engine being arranged behind the axle 13 for reasons to be explained hereinafter. The engine drives all four wheels of the vehicle through a twin shaft drive arrangement indicated generally at 21. Two trunnions 22 project upwardly from the chassis members 10 adjacent the engine 20 and pivotally support one end of a telescopically adjustable boom 23. The boom can be raised or lowered bv means of hydraulic rams 24 carried by the chassis members 10. In its fully elevated and fully extended position, the free end of the boom 23 will preferably lift a load to a position approximately twently one feet above the surface on which the vehicle rests. The maximum reach of the boom can, of course, be varied to suit requirements. When the boom is loaded, a turning moment is created about the axle 12 which reduces the load on the wheels 14 of axle 13. However by positioning the engine 20 over or to the rear of the axle 13 sufficient load on the rear wheels 14 can be maintained so that there is no loss of traction even when the boom is fully laden. The right hand chassis member 10 (when looking forwardly of the vehicle) supports a cab 30 for a driver. The cab is positioned so that the driver will have all round vision when the boom is lowered which is advantageous when travelling along highways. The free end of the boom may carry and suitable load carrier such as forks 25. In this case the forks are mounted by means of pivot 26 on a plate 27 which is carried by the boom, thus enabling the forks to be tipped sideways. Alternatively, of course, the forks could be rigidly mounted on the plate 27. Instead of forks, the boom could be adapted to carry a hook to be raised or lowered by a cable wound around a drum mounted on the chassis. Although specific reference has been made to a boom-type jib (which is normally extended by hydraulic means) the chassis may carry any other suitable kind of jib for load-lifting purposes. Also, whilst a fourwheel drive is preferred, a two-wheel drive arrangement may be adequate where the vehicle will not be used on boggy terrain. WHAT I CLAIM IS:

1. A vehicle which includes a chassis supported by first and second axles provided with ground wheels, each axle being mounted for pivoting relatively to the chassis frame about a vertical axis intersecting the longitudinal axis of the chassis, steering means for slewing the axles in opposite senses about their respective vertical axes relatively to the chassis, an engine for driving the ground wheels of at least one of the axle assemblies, and a crane jib mounted on the chassis.

2. A vehicle according to Claim 1, wherein the jib is of the telescopically add used able boom type, the longitudinal axis of which is contained in a vertical plane passing through the longitudinal axis of the chassis.

3. A vehicle according to Claim 2, wherein the engine is mounted either over the axle which is remote from the loadbearing end of the boom, or beyond that axle in a direction away from the load-bearing end of the boom.

4. A vehicle according to Claim 2 or 3, wherein the boom is pivotally connected to the chassis and can be raised or lowered by hydraulic rams.

5. A vehicle according to any preceding claim, wherein the ground wheels on each axle are driven.

6. A vehicle substantially as herein described, with reference to the accompanying drawings.