GB2134482A - Apparatus for self-elevation of vehicles - Google Patents

Abstract

An apparatus for the self-elevation of vehicles comprising a pair of ramps (1) connected together in parallel with each ramp mounted on similar substantially semi-circular support means (3), said means including at least one substantially flat circumferential portion (7, 8), in contact with the ground so that the ramps may pivot from an inclined position to a horizontal position and back in a controlled manner. The apparatus may be readily adapted to form a vehicle trailer. <IMAGE>

Description

SPECIFICATION Apparatus for self-elevation of vehicles The present invention relates to apparatus for the self-elevation of vehicles, for example, for under-body inspection purposes, and in particular to a ramp arrangement constructed so as to pivot from an inclined position to a horizontal position when a vehicle is driven thereon.

Hitherto, various ramp arrangements have been proposed for similar purposes, but in all such examples known to the applicant, pivoting or rolling from an inlined position to a horizontal position and back has, in practice, been difficult to control and thereby potentially hazardous. Curved ramp supports have invariably been curved about the same radius, which in the case of too small a radius of curvature, has resulted in uncontrolled overbalancing of the ramp when the centre of gravity of a vehicle moves too quickly over the pivotal axis of the ramp; and for too large a radius of curvature, has led to uncontrolled rocking, sometimes violently, of the ramp should a vehicle be driven on to the ramp either jerkily or in stops and starts.

The apparatus of the present invention effectively overcomes the disadvantages of the prior art and provides a ramp arrangement which may smoothly and controllably pivot from an inclined position to a horizontal position when a vehicle is driven thereon.

Thus, the present invention provides an apparatus for the self-elevation of vehicles comprising a pair of ramps connected together in parallel in which each ramp is mounted on similar, substantially semi-circular support means, said means including at least one substantially flat circumferential portion in contact with the ground, so that the ramps may pivot from an inclined position to a horizontal position in a smooth, step-like manner.

The apparatus of the invention is primarily designed for the elevation of conventional four or more wheeled vehicles, but may be readily adapted by the provision of a third intermediate ramp (which may or may not be mounted on support means) to accommodate threewheeled vehicles.

Preferably, the ramps comprise narrow, metal lattice runways of sufficient dimensions and strength to accommodate and support the vast majority of motor vehicles.

Desirably, each runway has a low retaining wall along each longitudinal edge to prevent the wheels of a vehicle from slipping off the runway, and similar end stop means, which conveniently may comprise part of the runway, which are capable of folding to provide support legs for the ramps when in the horizontal position.

The ramps are suitably connected together so as to maintain their parallelism, but such connections are adjustable so that the distance between the ramps can be altered to accommodate vehicles of differing wheel base widths.

The ramp support means preferably comprise a substantially semi-circular cylindrical tube of circular cross-section. Each support tube contains at least one flat portion, and desirably 2 to 4 such portions, so that the supports when rolling on a flat surface do so in a number of positive progressive steps as the ramps pivot either from the inclined to the horizontal position or from the horizontal to the inclined position.

The number and length of each flat portion, and the angle of each portion with respect to adjacent portions, is determined by the need for a smooth, progressive step-like pivoting action by the ramps when a vehicle is driven on to and off the apparatus, and may be radily found by simple trial and error.

Advantageously, the ramp support means are mounted slightly to one side of the centre of gravity of the ramps so that when at rest the ramps are in the inclined position. In these circumstances, it is clearly preferable for a vehicle to leave the ramps in the opposite direction to that from which it was driven on to the ramps, i.e. on and off the ramps from the same side. However, if the ramp support means are monted symmetrically about the centre of gravity of the ramps (which may require additional flat portions in the ramp support means), then a vehicle may, optionally, be driven off the ramps in the same direction as it was driven on to them.

The invention may be further described, but not limited, by reference to the accompanying drawings in which: Figure 1 depicts the apparatus of the invention in the inclined position with a vehicle approaching the centre of gravity thereof, Figure 2 depicts the apparatus in the final horizontal position, Figure 3 depicts the apparatus after modification to form a vehicle trailer, and Figure 4 depicts various parts of the apparatus before their assembly.

The apparatus in Fig. 1 comprises two identical ramp sections 1 connected together in parallel by tubular sections 2 (by means of locking pins at positions 1 a - Fig. 4) with each ramp mounted on similar, substantially semicircular, tubular support means 3. Tubular parts 2 and 3 are joined by slotting together and locking by the insertion of the ramp locking pins. A number of slotting positions may be provided to accommodate differing wheel base widths.

The ramps comprise narrow, deep metal lattice runways 4 to give a high resistance to bending, shown more clearly in Fig. 4, each with a low guiding and retaining wall 5 along the longitudinal edges thereof.The flat, metal zigzag strip lattice structure of each runway provides a good grip, increased rigidity and minimum rolling resistance, and uses a minimum amount of material. Each runway includes folding end sections 6 (Fig. 2), which provide end stop means on the runway and support legs for the ramps when in the horizontal position. The end sections may be conveniently locked either in line with the ramp or at right angles thereto by a spring pin arrangement. The ramp support means 3 comprise substantially semi-circular cylindrical tubes of circular cross-section, each with two flat portions 7 and 8.The portions 7 and 8 are asymmetrically arranged so that when the apparatus is in the horizontal position (Fig. 2) portion 8 only rests on the ground.

The support means 3 is slightly offset with respect to the centre of gravity of the apparatus, so that the ramps lie in the inclined position when not in use.

In operation a vehicle may be driven on to the ramps as shown in Figs. 1 and 2. The end stop means and front legs 6a are placed in position before the vehicle mounts the ramps and once the apparatus is in the horizontal position,the rear legs 6b are also locked into position.

Due to the presence of flat portions 7 and 8 in the support means 3 the apparatus pivots from the inclined to the horizontal position in a smooth and progressive step-like manner, which is completely hazard free when compared with the mode of operation of previous apparatus in the art.

A winch can be used to load/unload disabled vehicles on to/from the ramps, if necessary.

Fig. 3 shows a further feature of the present invention in which the construction of the apparatus allows a simple adaptation to a vehicle recovery trailer. The trailer adaptation parts, principally, two sets of wheels 9, each mounted on a small frame 10, an "A-frame", 11, tailboard (not shown), and optionally, bracing bars 12, are bolted to the structural members of the ramps to form a trailer. The recovery trailer may then be fitted with a winch 1 3 (to the "A-frame") to aid the loading/unloading of disabled vehicles and to secure the vehicle on the trailer.

Claims (11)

1. An apparatus for the self-elevation of vehicles comprising a pair of ramps connected together in parallel in which each ramp is mounted on a similar, substantially semi-circular support means, said means including at least one substantially flat circumferential portion in contact with the ground, so that the ramps may pivot from an inclined position to a horizontal position in a smooth,step-like manner.

2. An apparatus according to Claim 1 in which there is a third intermediate ramp.

3. An apparatus according to Claim 1 or Claim 2 in which the ramps comprise metal lattice runways.

4. An apparatus according to Claim 3 in which the runways have a retaining wall along each longitudinal edge thereof.

5. An apparatus according to any one of Claims 1 to 4 in which each ramp includes end stop means.

6. An apparatus according to Claim 5 in which the end stop means acts as support legs for the ramps.

7. An apparatus according to any one of Claims 1-6 in which the ramps are adjustably connected together.

8. An apparatus according to any one of Claims 1-7 in which the semi-circular support means has two to four substantially flat circumferential portions.

9. An apparatus according to any one of the previous claims in which the ramp support means are mounted to one side of the centre of gravity of the ramps.

10. An apparatus for the self-elevation of vehicles substantially as hereinbefore described with reference to Figs. 1, 2 and 4 of the accompanying drawings.

11. A vehicle trailer when adapted from the apparatus according to Claim 1.

1 2. A vehicle trailer substantially as hereinbefore described with reference to Fig. 3 of the accompanying drawings.