Vehicle Suspension With Rigid Torque Beam

In the construction heretofore built of this type, the Raidel U.S. Pat. No. 3,801,086 represents one in which a special hanger mounting is provided for attachment to the vehicle frame, to accommodate the bushing attaching the end of the torque beam to the vehicle. It is an object of the present invention to design the torque beam so that it can be attached directly to a frame of the vehicle, such as could be found in a drop frame trailer.

In the prior art there has been a resilient bushing connecting the torque beam to the hanger and that bushing had its outer cylinder connected to or forming a part of the torque beam itself. In the present invention, that outer cylinder of the resilient bushing is permanently welded to the frame of the vehicle. In the former structure, the hanger bracket came down in two sections on the opposite ends of the bushing. In the present arrangement, there is a single primary connection in the form of the attachment of the outer cylindrical sleeve of the bushing to the web of the frame of the vehicle, and two arms of the torque beam are connected to the pivot of the bushing at opposite ends of the pivot and are non-rotatably secured thereto. These two ends of the torque beam in the present disclosure thus are separated so as to straddle the flange on the frame of the vehicle, but they are then tapered toward each other so that they can fit between the two side arms of the lower or buffer beam. An object of the invention is a suspension of the foregoing type that can accommodate differences in elevation between opposite ends of the axle. Another object is a suspension having the foregoing advantages, wherein there is a fore-and-aft adjustment of each suspension to insure wheel alignment and to provide a suspension of this type wherein the torque beam and its attachment to the frame may have the foregoing features enabling this type of suspension to be mounted directly on the vehicle frame. A further object of the present invention is to design the foregoing parts so that they can be largely pre-assembled readily and then mounted onto the vehicle.

Thus, the objects of the present invention are to provide a suspension assembly of this type that can be used with drop frame vehicles and that is strong, that is easy to assemble, and yet that achieves the comfortable ride and the accommodation of the different movements of the axle relative to the frame.

In the drawings:

FIG. 1 is a side elevation of a portion of the vehicle frame to which the present invention is mounted;

FIG. 2 is a top view of the construction of FIG. 1;

FIG. 3 is an end view taken from the left end on the line 3--3 of FIG. 1;

FIG. 4 is a rear view taken from the right end on the line 4--4 of FIG. 1;

FIG. 5 is a section on the line 5--5 of FIG. 1; and

FIG. 6 is an enlarged transverse section through the torque beam bushing taken on the line 6--6 of FIG. 1.

FIG. 1 shows a drop frame 20 in the form of an I-beam with a web 21 and flanges 22 and 23. As shown at the left of FIG. 1, it drops down between the axles by way of a downwardly-sloping portion 231 to a lower level.

It will be understood that the present mechanism, while illustrated for the left rear wheel, is representative of the other three similar assemblies that may be applied to the other wheels, both on the left and right sides. The right side assemblies are in certain portions, mirror images of the left side, and the forward axle assemblies are in part mirror images of the rear ones. It will be understood that each axle supports a wheel at each end. Also, the assembly as illustrated, uses an underslung arrangement, but it can readily be adapted to an overslung construction.

The overall assembly to suspend the frame 20 onto an axle housing 28 comprises a torque beam 32 here attached at its forward end to the frame by a resilient bushing assembly 35 and connected at its rear end to a lower or buffer beam 37 by two such bushings 38 and 39. The lower beam 37 is in turn welded to the axle housing 28 by means to be described. It also supports at its rear portion an air spring 40 that is attached to the frame. A shock absorber 43 is swiveled to the lower beam 37, at 44, and is also swiveled to the frame of the vehicle at 45. Thus, the frame is connected to the opposite ends of the torque beam 32 and the lower beam 37, respectively, which beams are secured together through the bushings 38 and 39, and the whole structure is connected to the axle housing 28 by having the lower beam 37 welded to that housing.

The mounting of the bushing assembly 35 to the frame 20 is as follows. A hole 48 is cut in the web 21 to receive the bushing assembly 35 (FIG. 6). This assembly 35 includes a cylindrical sleeve 50 passing through the hole 48, and welded to the web 21. The bushing assembly comprises another cylindrical sleeve 52 concentrically fitted into the sleeve 50, within which is mounted a cylindrical rubber or other elastomeric member 54; and inside that is an additional cylindrical sleeve 55. The sleeve 55 is mounted over an eccentric bolt 56 that has an eccentric portion 57 that appears in FIG. 6. This eccentric portion of the bolt 56 may have the form shown in FIG. 14 of U.S. Pat. No. 3,510,149, secured to the surface of the otherwise cylindrical bolt.

When the foregoing bushing assembly 35 is properly positioned, four welds are placed around each end, joining the sleeve 50 and the cylinder 52.

The attachment of the torque beam and the bushing is made as follows. A bolt 56 is inserted (from the left in FIG. 6) through a non-circular, here rectangular, frame 64a that is an extension fixed to the end of one sidearm 68a of the torque beam, as will appear. A non-circular plate 65a, shaped to fit inside the frame 64a, is located on the bolt before the eccentric portion is mounted thereon.

Passing them through an opening 67 in the plate 65a, and a similar opening in the torque bar arm 68a, the bolt 56 is pushed through the sleeve 55 that has a diameter equal to the larger diameter of the eccentric mounting on the bolt. At its other end, the reduced portion of the bolt 56 passes through the opening 69 in the other side arm 68b of the torque bar 32 and the opening in the plate 65b in the frame 64b, and projecting thus it receives the nut 70.

As will be evident, turning of the bolt 56 about its axis displaces the eccentric portion 57. Since the bushing assembly 35 is welded to the frame, the displacement caused by the turning of the eccentric displaces the arms 68a and 68b, and hence the entire torque bar 32, in a generally-forward or rearward direction, depending on the direction of rotation of the bolt.

The side arms 68a and 68b of the torque beam have side reinforcing plates 71a and 71b welded to them and to their end frames 64a and 64b. The beams 68a and 68b, after reaching beyond the frame flange 23, converge (FIG. 2) until they reach parallel sections, 68c and 68d, respectively, that extend rearwardly to the bonded rubber bushing assembly 38, that extends across through both. They are also connected by a bottom plate 75 and a bottom plate 76. They are also connected by an upper plate 77 and other upper plates 78 that are continuations of 77. The overall purpose is to create a sturdy box-like beam structure that can straddle the frame 20, and yet fit between the side arms of the lower beam 37.

The lower beam 37, which is swiveled by bonded rubber bushing assembly 38 (U.S. Pat. No. 3,801,086) to the torque beam 32, extends approximately midway forwardly adjacent the torque beam 32. At its forward end it is connected by a bonded rubber bushing 39 (see U.S. Pat. No. 3,801,086) to the torque beam 32, that is notched to receive the bonded bushing 39. The busing 39 is welded to the torque beam between the bottom plates 75 and 76. The bonded bushing 38 and 39 secure the two beams 32 and 37 together.

Lower beam 37 consists of two U-channelled side arms 85a and 85b that are joined together by the two bushings 38 and 39. The arms 85a and 85a have angular plates 87a and 87b welded to them and projecting upwardly above them. The plates 87a and 87jb are recessed to fit approximately halfway around, and are welded to, the axle casing 28. There are also plates 90a and 90b forward of the housing that are welded to and outside of the plates 87a and 87b. Between the plates 90a and 90b and inside the plates 87a and 87b, an intermediate vertical plate 91 is welded. There is also a plate 92 welded between the plates 87a and 87b to add to the rigidity of the construction.

The structure at the rear side of the axle is similar with outer plates 95a and 95b, and intermediate a vertical plate 96, all welded to the angular vertical plates 87a and 87b and to the axle housing 28. There is also a reinforcing plate 98 between the two angular plates 87a and 87b. Thus, the axle housing 28 is adapted to be welded into the semi-circular cut-out in the plates 87a and 87b, and to be welded to the plates 90a and 90b, 95a and 95b, 91 and 96.

To the rear of the foregoing, a mounting to hold the air spring 40 onto the lower beam 37 includes a base plate 102 supported across the U-members 85a and 85b as shown particularly in FIGS. 1 and 4. A gusset 103 is welded to the parts to give support to the lateral extension of the base plate 102. Cap screws or the like 105 hold the bottom of the air spring onto the plate 102. At the top the air spring is secured by bolts 106 and 107 to a plate 108 and to the bottom flange 23 of the frame 21. Another gusset 109 aids in supporting the plate 108.

One end of the conventional shock absorber 43 is secured by a pivot bracket 110 to a base plate 111 that is welded across the bottom of the channels 85a and 85b as shown particularly in FIG. 4. A plate 112 is welded to the channel 85b and the bracket 111 to support the latter. The other end of this shock absorber is rockably mounted on a cross beam member 113 of the vehicle frame by a bracket 114 that extends outwardly and forwardly from the cross beam. Gussets 116 support the bracket 114. The attachment of the shock absorber is made by a bushing assembly that can be tightened to alter the torque resistance of any rocking action of the shock absorber, which of course will occur when the air spring is compressed or elongated vertically.

In setting the equipment into place, the torque beam 32, the lower beam 37, the air spring 40, with their associated parts, are pre-assembled together. Then measurements are made to locate the bolt holes for the air spring 40, and the hole for the bushing assembly 35. The sleeve 50 of the bushing 35 is then welded in place to the flange 21, as shown in FIG. 6. The bushing assembly including the sleeve 52, the rubber member 54 and the sleeve 55 are then put in place, aligned, and the sleeve 52 is welded to the sleeve 50 at four points around each end.

The bolt 56 with the plate 65a already in place on it, is then passed through the frame 64a and the member 68a of the torque beam, thence through the sleeve 55 and through the other plate 68b of the torque beam, the plate 65b and the frame 64b, and finally the nut 70 which is tightened. This disposes the square plates 65a and 65b within the square frames 64a and 64b and these parts are held non-rotatably together. The bracing frames 117a and 117b may be added to the assembly within the frame to stabilize the assembly.

The bracket 114 having been welded onto the cross frame 113, the air spring 40 is attached to the flange 23 of the frame by the bolts 106 and 107, and a shock absorber 43, already usually attached to its lower end, is attached by the pivot bolt 45 to the bracket 114 on the frame.

The plates 87a and 87b then embrace the axle housing 28 and are welded to it, as shown. Also, the plates 90a, 90b and 92, as well as the plates 95a, 96b and 98 are all welded to the axle housing, as shown.

The order in which the foregoing parts are assembled onto the vehicle is not necessarily critical. It will be understood that there will be one such assembly at each end of each axle.

The next stage of assembly is to tighten the nut 70 of the bushing 35 and the corresponding nuts of the bushings 38 and 39 to a torque of 1100 foot pounds, and to tighten the shock absorber nut on connection 44, and the one at the connection 45, each to a torque of 150 foot pounds.

At this time, the arrow appearing on the end of the bolt 56 of the bushing 35 must be at the twelve o'clock position. Then to align the axle, the nut 70 is loosened and the bolt head 59 is turned counterclockwise or clockwise in the direction the axle has to be moved to obtain perfect alignment. It will be understood that the adjustment on the opposite end of the axle housing can be adjusted cooperatively to obtain the appropriate alignment of the axle. The maximum movement forward or backward is to the nine o'clock or the three o'clock position. When the appropriate final alignment is obtained, the nuts 70 are retightened to set the torque at 1100 pounds. Then the clamping plates 65a and 65b are welded to the torque beam assembly 64a, 68a and 64b and 68b.

With the adjustments completed, and these parts thus secured, the U-shaped locking plates are fitted over the bolt head 59 and the nut 70 of the bolt 56, and are welded to the adjacent plates 65a and 65b.

As the vehicle is loaded, or as the wheels pass over a hump, the frame and the axle housing 28 are compressed toward each other. Considering it as if the wheel rides onto a hump, the lower, or buffer, beam 37 is raised to compress the air spring 40, as well as to pivot the torque beam 32 to pivot about the bushing 35. This applies compression or torque about all three bushings 35, 38 and 39, and they all apply resilient resistance thereto.

When only one side of the vehicle rides over a hump, the resilient bushings 38 and 39 can flex angularly, or transversely to their axes, accommodating the angular effect on the axle housing 28 without severe strain on the torque beam that is mounted onto the frame, the bushings 38 and 39 permitting such action. The narrow shape of the lower beam disposed between the arms 85a and 85b provides this action. The torque beam is essentially not permitted to rock longitudinally about its resilient bushing, owing to the close fit of its sleeve between the arms 68a and 68b. Hence the displacement vertically of only one wheel can rock the lower beam without rocking the torque beam. As a result, the axle 28 may rock about a fore-and-aft axis without rocking the vehicle frame and body. The shock absorber is mounted to the frame 20 by a resilient bushing, so that it may accommodate the foregoing movements.

The parts of this equipment not otherwise indicated are usually made of steel.

There are various changes and modifications which may be made to applicant's invention as would be apparent to those skilled in the art. However, any of these changes or modifications are included in the teaching of the applicant's disclosure and he intends that his invention be limited only by the scope of the claims as appended hereto.