GB2224265A

GB2224265A - Wheel assembly for a beam jack

Info

Publication number: GB2224265A
Application number: GB8911246A
Authority: GB
Inventors: Derek William Rowswell
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-05-19
Filing date: 1989-05-17
Publication date: 1990-05-02
Anticipated expiration: 2009-05-17
Also published as: GB2218686A; GB2224265B; GB8911246D0; GB8811897D0

Abstract

A wheel assembly for a beam jack has a bar (1) for connection at each lateral side of the jack. Each bar has a horizontal flange (1a) for overlying the edge of an inspection pit. It also has wheel carriers (3) that carry vertically displaceable wheel means (4) urged downwardly for contacting the pit edge. When the jack is unloaded, the urging lifts the flanges up so the jack is displaceable. Loading moves the flanges down onto the pit edge. The wheel carrier may be telescopically mounted (as shown), or pivotably mounted (Fig. 2A, not shown). <IMAGE>

Description

1 222426j 1 WHEEL ASSEMBLY FOR A BEAM JACK The present invention relates

to a wheel assembly for a beam jack.

The new standard M.0.T. 1.5 tonne hydraulic beam jack is much heavier than the 1.00 tonne hydraulic beam j ack which it replaces for use in M. 0. T. vehicle testing stations. This means that the new generation beam jacks are very difficult for operators to push along the ramps or vehicle inspection pits to position under vehicles.

The present invention provides a wheel assembly for connection to a beam jack for operation over an inspection pit having parallel longitudinal edges, the assembly comprising a pair of like sub- assemblies each of which comprises an elongate support member having means for connection to a beam jack and a horizontally extending portion having a downwardly facing abutment surface; wheel means carried by a wheel carrier which is mounted to said member so as to be vertically displaceable so that the wheel means are displaceable between configurations in which they do and do not project beneath said abutment surface; and resilient means urging said projection; the arrangement being such that said sub-assemblies are connectable at respective sides of a beam jack so that the wheel means can run on the longitudinal edges of a pit, the spring means 2 maintaining said projection when the jack is unloaded; but loading of the jack can urge the abutment surfaces into contact with the pit edges.

Such an assembly may be fitted under a beam jack's existing angled steel arms to facilitate easy movement along the full length of ramp or pit. Thus in another aspect the invention provides beam jack assembly comprising a beam jack and a wheel assembly of the above type connected to it, one sub-assembly at each of two opposite sides of the jack.

Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Fig. 1 is a perspective view of one sub-assembly of a first embodiment; and Figs. 2A and 2B are front and rear perspective views of a sub-assembly of a second embodiment.

Fig. 1 shows an angled steel arm 1 having apertures for bolts for connection to a jack. At each end the horizontal arm la is cut away so as not to interfere with a wheel assembly 2,3,4 mounted to the downwardly extending arm lb. Each wheel assembly includes a -box section housing 2 welded vertically to the arm lb, a square section steel bar slider 3 that passes through the housing 2 and a sheathed bearing wheel 4 journalled on a shaft by a bolt spindle which extends from an upper t 1 X 3 portion of the slider 3. Load bearing compression springs 5 are held by retaining bolts to the base of the slider assemblies.

For use, two like sub-assemblies are connected beaneath a beamjack so that the wheels 4 and horizontal arms la can overlie the edges of an inspection pit. When the beam Jack is unloaded it runs freely on the wheels 4 along the full length of the pit and any adjoining ramp. This is facilitated by the weight of the beam jack being supported by the compression springs 5 which allow the angled steel arms 1 to remain clear of the sliding surfaces.

When the jack is loaded i.e. when jacking a vehicle, the springs compress as the square section bar steel sliders 3 move up vertically relative to their housings 2. This allows the horizontal arms la to seat upon the lips of the ramp or pit and permit stable jacking.

The jack returns to its free running position immediately it is unloaded i.e. immediately the vehicle is lowered to the ramp.

Fig. 2 shows another embodiment. This has many elements in common with the first, and these are given the same reference numerals. The mounting of the wheels 4 to the upright arms lb is different. At each end of each arm lb a lever 11 is pivoted via a pivot pin 12. A bearing spindle bolt 14 spaced from the pin 12 carries 4 the wheel 4 and also engages a tension spring 16, which extends to a lower pin 18 on the arm lb and acts to pull the lever 10 downwardly. Its downward travel is limited by abutment with the upper surface of the arm lb to which 5 it is pivoted.

Both embodiments employ coil springs. Other types, e.g. torsion springs, could be used but are not at present preferred.

1 A

Claims

1. A wheel assembly for connection to a beam jack f or operation over an inspection pit having parallel longitudinal edges, the assembly comprising a pair of like sub-assemblies each of which comprises an elongate support member having means for connection to a beam jack and a horizontally extending portion having a downwardly facing abutment surface; wheel means carried by a wheel carrier which is mounted to said member so as to be vertically displaceable so that the wheel means are displaceable between configurations in which they do and. do not project beneath said abutment surface; and resilient means urging said projection; the arrangement being such that said sub-assemblies are connectable at respective sides of a beam jack so that the wheel means can run on the longitudinal edges of a pit, the spring means maintaining said projection when the jack is unloaded; but loading of the jack can urge the abutment surfaces into contact with the pit edges.

2. A wheel assembly according to claim 1 wherein each wheel carrier is an upright rod which is mounted to guide means on its support member so as to be linearly displaceable.

3. A wheel assembly according to claim 1 wherein each 25 wheel carrier Is a rod which is pivoted to its support member.

6

4. A wheel assembly according to any preceding claim wherein the spring means are coil springs.

5. A wheel assembly according to any preceding claim wherein each subassembly has a longitudinally spaced 5 pair of wheel carriers mounted to it.

6. A wheel assembly substantially as herein described with reference to and as illustrated in the accompanying drawings.

7. A beam jack assembly comprising a beam jack and a 10 wheel assembly according to any preceding claim connected to it, one sub-assembly at each of two opposite sides of the jack.

Published 1990 at The Patent OVIce, State House,66171 High Holborn. London WCIR 4TP. Further copies maybe obtained from The Patent Office. Sales Branch, St Mary Cray, Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1/87