Vehicle Chassis Clamp

The present invention relates to a vehicle chassis clamp for clamping against a selected chassis part that exhibits a throughpassing bolt connection or joint.

The work, for example, of determining the measurements of damaged vehicle chassis and of straightening (aligning) such chassis is normally carried out with the chassis secured to an alignment bench with the aid of chassis clamps attached, for instance, to the pinch weld connecting the doorsill assembly and the vehicle floor to the chassis. The pinch weld of vans and like light trucks or lorries is not strong enough for this purpose, and consequently it is necessary to support the chassis of such vehicles at other attachment locations, with the aid of separate clamps of particular construction. Hitherto, however, no such clamp has been proposed which is totally reliable in operation and which can be secured to the chassis with sufficient precision and with sufficient clamping effect.

Consequently it is the object of this invention to provide a vehicle chassis clamp which can be positioned accurately on and clamped securely to the vehicle chassis at locations other than the aforesaid pinch weld in a manner to hold the chassis with rigid firmness. Accordingly, the invention is based on the understanding that the chassis clamp shall be attached to parts of the chassis that are strong and robust and which present a throughpassing bolt connection or joint. One example of chassis parts which are both strong and present a bolt joint is the suspension (spring) attachments of the vehicle, these attachments normally being fitted to those parts of the chassis that are expected to take-up particularly large forces.

A clamp constructed in accordance with the invention and comprising a stirrup-like section having associated therewith apertured clamping means which each embrace a respective end of the bolt joint is extremely powerful and positionally stable. A certain amount of play can be tolerated therewith between the defining walls of the apertures of the clamping means and the components of the bolt joint.

The invention will now be described in more detail with reference to the accompanying drawings, which illustrate a preferred embodiment of a chassis clamp according to the invention.

FIG. 1 illustrates in perspective a conventional vehicle chassis a vehicle chassis clamp according to the invention, with the clamps firmly clamped to a vehicle chassis.

FIG. 2 is an enlarged view in perspective of the chassis clamp of the invention illustrated in FIG. 1, and shows this clamp from a different angle.

FIG. 3 is a perspective view of the components of the chassis clamp according to the invention, and is drawn to the same scale as FIG. 2.

FIGS. 4a-d illustrate four different stages of fitting a chassis clamp according to the invention to part of a vehicle chassis.

In FIG. 1 there is shown a conventional clamp 3 which comprises two clamping jaw plates 1 and 2 and which is intended for clamping engagements with a pinch weld 4 on a vehicle chassis 5. Also shown in FIG. 1 is a chassis clamp 6 according to the invention clamped onto a spring attachment 7 on the chassis 5. Both clamps 3 and 6 have attachment means 8 and 9, for securing the clamp to a respective guide beam 11 and 12 mounted on an alignment bench 10.

The chassis clamp 6 according to the illustrated embodiment of the invention includes a substantially U-shaped stirrup bracket 6a which is attached securely (e.g. welded) to a carrier plate 6b (or alternatively is made in one piece therewith). The two limbs 6c and 6d of the stirrup bracket are straight and parallel with one another, and each presents a respective screw threaded hole or bore 6e and 6f which face one another and are preferably mutually co-axial. The limbs 6c and 6d are intended to straddle the spring attachment 7, (see FIGS. 1, 2 and 4c) which has a throughpassing bolt connection or joint 13 (see FIG. 4c). To this end each of the limbs 6c and 6d is provided with respective clamping devices for clamping against respective outer surfaces of the attachment 7. In the illustrated embodiment these clamping devices have the form of two externally screw threaded sleeve bushes 14 and 15, each of which can be screwed into a respective hole 6e and 6f. The bush 14 comprises an externally screw threaded part 14a which can be screwed into the hole 6e and which has an axially throughpassing hole 14b (shown inter alia in FIGS. 4a and 4c), the dimensions of which are at least equal to the free end 13a of the bolt in the bolt joint 13 (see FIG. 4a), and further comprises a plain sleeve part 14c with a radial dimension which is larger than that of the hole 6e, whereby the sleeve part 14c of the bush forms a stop against the limb 6c when tightening the bush 14. The hole, or bore, 14b extends a short distance into the sleeve part 14c, to merge with an axial hole 14d (see FIG. 4a) which has the same radial dimension as the nut 13b of the bolt joint 13 (FIG. 4c). At those instances when less stringent requirements are placed on the accuracy to which measurements are taken, a certain amount of play can be tolerated between the walls of the hole, or bore, 14b and the nut 13b. In order to fit the bolt joints of different vehicle models, the hole 14b of the bush 14 may be given varying dimensions, as illustrated in FIG. 3 by the four examples 14, 14', 14", and 14"'.

When fitting the clamp 6 in confined, awkward spaces, it is not always possible to tighten the bush 14 hard to the bottom, but must be left loosely screwed into its respective hole. Consequently, in order to enable the bush 14 to be positioned accurately in a given position, the clamp incorporates an insert element in the form of a split ring 16 (FIG. 3) which is placed over the bush 14, between the limb 6c and the sleeve part 14c, thereby enabling the bush 14 to be tightened until the sleeve part 14c bears against a bevelled surface 16a on the ring 16.

The bush 15 comprises an externally screw threaded bolt part 15a (FIG. 3) which can be screwed into the hole 6f and the threaded portion of which terminates short of the free end of the bolt part of said bush and adjoins in this region of the bush a section 15b of hexagonal cross-section, by means of which the bush 15 can be turned and therewith be moved axially towards the first mentioned bush 14.

The other end of the bolt part 15a has provided therein a bore 15c (see for example FIG. 4b) such that the bolt part forms a sleeve bush in this region thereof, and merges with a plain sleeve part 15d of larger radial dimension than the hole 6f, whereby the sleeve part 15d forms a stop against the limb 6d when tightening the bush 15 thereagainst. The bore 15c extends slightly into the sleeve part 15d and there merges with an axial hole or bore 15e (e.g. FIG. 4b) having the same radial dimensions as the bolt head 13c of the bolt joint 13 (FIG. 4c). A certain amount of play can be tolerated between the defining surfaces of the hole 15e and the bolt head 13c, when requirements on measuring accuracy are less stringent. To enable the clamp to be used with different models of vehicle, the hole 15e of the bush 15 is given varying dimensions, analogous with that described with reference to the bush 14.

The carrier plate 6b of the clamp has provided therein a plurality of throughpassing, screwthreaded holes 17 which accommodate bolts 18 for screwing the clamp firmly to the beam 12 with the aid of clamping plates 19, as shown in FIG. 2.

FIG. 4a-4d illustrates the various stages of fitting the chassis clamp. Fitting of the clamp is preferably commenced by inserting a bush 14 into the hole 6e, FIG. 4a, and tightening the bush until it bottoms in the hole, provided that the insert 16 is not required for the reasons mentioned above. The bush 15 is then screwed into the hole 6f, FIG. 4b, and fully tightened to the bottom of the hole, so as to obtain the widest possible gap between the bushes 14 and 15. The clamp is then hung over the free end of the bolt joint 13a-b, FIG. 4c, and the clamp lifted until it registers with the head 13c of the bolt joint, see FIG. 4d. The bush 15 is then screwed in against the spring attachment 7, so as to tighten the clamp firmly thereto. The clamp can then be secured to the guide beam 12 by means of the bolts 18 and the clamp plates 19, as described in the aforegoing (see e.g. FIG. 2).