Axle suspension systems

• US 5,366,237 A
• Filed: 04/20/1994
• Issued: 11/22/1994
• Est. Priority Date: 10/19/1992
• Status: Expired due to Term

• Current Assignee: The Boler Company
• Original Assignee: The Boler Company
• Inventors: Dilling, Scott, Ramsey, John, Ross, Joseph M., Keeler, Michael J.
• Primary Examiner(s): Johnson, Brian L.
• Assistant Examiner(s): Dickson, Paul N.
• Application Number:
  US08/230,136
• Time in Patent Office: 216 Days
• Field of Search: 280/711, 280/712, 280/713, 280/725, 280/683
• US Class Current: 280/124.116
• CPC Class Codes: B60G 11/27 wherein the fluid is a gas
• CPC Class Codes: B60G 21/051 Trailing arm twist beam axles
• CPC Class Codes: B60G 2200/21 Trailing arms connected by a torsional beam, i.e. twist-beam axles
• CPC Class Codes: B60G 2200/31 with two trailing arms rigidly connected to the axle
• CPC Class Codes: B60G 2202/135 Stabiliser bar and/or tube
• CPC Class Codes: B60G 2202/142 subjected to shear, e.g. Neidhart type
• CPC Class Codes: B60G 2202/1424 Torsional
• CPC Class Codes: B60G 2202/152 Pneumatic spring
• CPC Class Codes: B60G 2204/128 Damper mount on vehicle body or chassis
• CPC Class Codes: B60G 2204/129 Damper mount on wheel suspension or knuckle
• CPC Class Codes: B60G 2204/14 Mounting of suspension arms
• CPC Class Codes: B60G 2204/143 on the vehicle body or chassis
• CPC Class Codes: B60G 2204/41 Elastic mounts, e.g. bushings
• CPC Class Codes: B60G 2204/4104 Bushings having modified rigidity in particular directions
• CPC Class Codes: B60G 2204/4306 Bracket or knuckle for rigid axles, e.g. for clamping
• CPC Class Codes: B60G 2206/11 the arm being a radius or track or torque or steering rod or stabiliser end link
• CPC Class Codes: B60G 2206/601 Hanger bracket
• CPC Class Codes: B60G 2206/8201 by welding
• CPC Class Codes: B60G 7/001 Suspension arms, e.g. constructional features B60G7/006 takes precedence
• CPC Class Codes: B60G 7/02 Attaching arms to sprung part of vehicle B60G7/006 takes precedence
• CPC Class Codes: B60G 9/003 : the axle being rigidly connected to a trailing guiding device

Abstract

A beam-type axle suspension system particularly applicable to trailers and which is subject to torsional forces includes an elongated beam, a pneumatic bellows located on the beam, a hanger bracket located at one end of the beam, a connection for rigidly connecting the beam to the axle and a resilient pivot connection for resiliently connecting the beam to the hanger bracket wherein the beam includes an orifice through which the axle is slid or pressed and rigidly attached thereto, thereby preventing the axle from assuming a cross-sectional shape substantially different from its unstressed shape due to the torsional forces imposed on the axle. This beam-type axle suspension system also includes a resilient pivot connection for connecting the hanger bracket to the beam, thereby allowing the brake components to be attached to the beam instead of to the axle, and having the effect of eliminating stress risers on the axle due to welding the brake components to the axle. This is achieved by the combination of a pivot connection having a resilient bushing with different deflection in the beamwise and hangerwise directions and the rigid axle-to-beam connection which maintains a constant distance between the axle and the brake components.

Claims

1. In an axle bearing suspension system of the leading or trailing beam type for a wheeled vehicle wherein external forces imposed on the vehicle to which said suspension system is attached, result in torsional forces being imposed on said axle such that a portion of said axle is placed in compression and a portion of said axle is placed in tension to alter the cross-sectional configuration of said axle, said suspension system including a pair of elongated beams, one of said beams being located adjacent each side of said vehicle and each spaced from the other, each said beam including a pair of side walls extending in substantially the vertical direction with respect to said vehicle, said axle being of a hollow cross-sectional configuration and extending across substantially the entire width of the vehicle and having at least one wheel located on each end thereof, a pneumatic bellows located on each said beam, a hanger bracket located on one end of each said beam for connecting said beam to a frame member of said vehicle, means for rigidly connecting said axle to each said beam, and a pivot connection for resiliently connecting said beam to said hanger bracket, the improvement comprising:

wherein said means for rigidly connecting said axle to said beam includes means for preventing said alteration of the cross-sectional configuration of said axle, comprising an orifice in each said side wall of each said beam through which said axle extends and which substantially surrounds said axle and is rigidly attached thereto, said axle extending completely through and beyond each of said orifices, whereby said axle cross-sectional configuration is prevented from assuming a cross-sectional configuration substantially different from an unaltered configuration when said torsional forces are imposed upon said axle.

2. The axle suspension system of claim 1 wherein said pivot connection for resiliently connecting said beam to said hanger bracket comprises an elastic means having a different degree of deflection beamwise than hangerwise, said elastic means being located at a spaced distance from said axle connecting means in the path of articulation forces between the beam and hanger bracket and being sufficiently resilient to allow operative deflections in response to said articulation forces, and at the same time restrain longitudinal movement sufficiently to maintain substantially constant the distance between the hanger bracket and the axle connecting means.

3. The axle suspension system of claim 2 wherein the elastic means is contiguous to the hanger bracket.

4. The axle suspension system of claim 3 wherein the elastic means has a different spring rate in the vertical than in the horizontal.

5. The axle suspension system of claim 4 wherein the hangerwise deflection of the elastic means is greater than the beamwise deflection and the spring rate in the vertical is less than in the horizontal.

6. The axle suspension system of claim 5 wherein the pivot connection for resiliently connecting the hanger bracket and the beam includes a retaining pin transverse to the direction of the elongated beam and connected to said hanger bracket, a tubular metal cylinder in which said pin non-rotatably resides and wherein said elastic means comprises an elastic tubular element, the inner surface of which is securely held to said metal cylinder such that substantially all pivotal movement about said pin is within the elastic element.

7. The axle suspension system of claim 3 wherein the pivot connection for resiliently connecting the hanger and beam includes a pivot connection attached to the hanger and said elastic means comprises an element having a different degree of deflection beamwise than hangerwise.

8. The axle suspension system of claim 7 wherein the hanger bracket comprises two transversly spaced plates and said pivot connection for resiliently connecting the beam and the hanger bracket comprises a retaining pin extending between and connected to the plates, said elastomeric element extending around said pin and being of tubular shape, said element being held securely with respect to said pin such that substantially all pivotal movement about said pin is within the elastomeric element.

9. The axle suspension system of claim 8 wherein said tubular elastomeric element is thick walled, and the face of each wall at either end of said element is provided with at least one cavity capable of providing a lesser degree of deflection beamwise than hangerwise in said element.

10. The axle suspension system of claim 9 wherein there are two cavities in each face of said elastomeric element spaced at a vertical distance from said retaining pin thereby to provide a greater degree of deflection hangerwise than beamwise and a greater spring rate in the horizontal than in the vertical direction.

11. The axle suspension system of claim 1 wherein said orifice in said beam is substantially the same size and shape as said axle, and wherein said rigid attachment of said axle to said beam is by welding.

12. The axle suspension system of claim 1, wherein the rigid attachment of said axle to said beam is by welding continuously 360°

around the circumference of said axle.

13. In an axle bearing suspension system of the leading or trailing beam type for a wheeled vehicle wherein external forces imposed on the vehicle to which said suspension system is attached, result in torsional forces being imposed on said axle such that a portion of said axle is placed in compression and a portion of said axle is placed in tension thereby tending to alter the cross-sectional configuration of said axle, said suspension system including a pair of elongated beams, one of said beams being located adjacent each side of said vehicle and each spaced from the other, each said beam including a pair of side walls extending in substantially the vertical direction with respect to said vehicle, said axle extending across substantially the entire width of the vehicle and having at least one wheel located on each end thereof, a pneumatic bellows located on each said beam, a hanger bracket located on one end of each said beam for connecting said beam to a frame member of said vehicle, means for rigidly connecting said axle to each said beam, and a pivot connection for resiliently connecting said beam to said hanger bracket, the improvement comprising:

said means for rigidly connecting said axle to said beam comprising an orifice in each said side wall of each said beam through which said axle extends and which substantially surrounds said axle and is rigidly attached thereto, and further comprising sleeve means rigidly attached to and substantially surrounding said axle and wherein said orifice in said beam substantially surrounds said sleeve means and is rigidly attached thereto, said axle extending completely through and beyond each of said orifices and said sleeve means, whereby said axle cross-sectional configuration is prevented from assuming a cross-sectional configuration substantially different from an unaltered configuration when said torsional forces are imposed upon said axle.

14. The axle suspension system of claim 13 wherein said sleeve means further comprises window means, said window means having an edge for welding said sleeve means to said axle, such that when said axle is connected to said sleeve means by welding along said edge, and no other, there exists no weld at a location where said axle is placed in maximum tension by operative bending forces.

15. The axle suspension system of claim 13, wherein said weld is continuous.

16. In an axle bearing suspension system for a wheeled vehicle wherein external forces imposed on the vehicle to which said suspension system is attached result in torsional forces being imposed on said axle, said suspension system including a brake actuation mechanism comprised of a brake chamber, an S-cam assembly comprising an S-cam bearing, a slack adjuster, an elongated beam, a pneumatic bellows located on said beam, a hanger bracket located at one end of said beam, means for rigidly connecting said axle to said beam, and a pivot connection for resiliently connecting said beam to said hanger bracket, the improvement comprising:

means located on said beam for attaching said S-cam bearing directly to said beam, and means for directly attaching said brake chamber to said beam.

17. The suspension system of claim 16 wherein said means for rigidly connecting said axle to said beam comprises an orifice in said beam which substantially surrounds said axle and is rigidly attached thereto, thereby to prevent said axle from assuming a cross-sectional shape substantially different from its unstressed shape when said torsional forces are imposed upon it.

18. The axle suspension system of claim 17 further comprising sleeve means rigidly attached to and substantially surrounding said axle, and wherein said orifice in said beam substantially surrounds said sleeve means and is rigidly attached thereto.

19. The axle suspension system of claim 18 wherein said sleeve means further comprises window means, said window means having an edge for welding said sleeve means to said axle, such that when the axle is connected to said sleeve means by welding along said edge, and no other, there exists no weld at a location where said axle is placed in maximum tension by operative bending forces.

20. The axle suspension system of claim 18, wherein said rigid attachment of said beam to said sleeve means is by continuously welding 360°

about said sleeve means.

21. The axle suspension system of claim 16 wherein said pivot connection for resiliently connecting said beam to said hanger bracket comprises an elastic means having a different degree of deflection beamwise than hangerwise, said elastic means being located at a spaced distance from said axle connecting means in the path of articulation forces between the beam and hanger bracket and being sufficiently resilient to allow operative deflections in response to said articulation forces and at the same time restrain longitudinal movement sufficiently to maintain substantially constant the distance between the hanger bracket and the axle connecting means.

22. The axle suspension system of claim 21 wherein the elastic means is contiguous to the hanger bracket.

23. The axle suspension system of claim 22 wherein the elastic means has a different spring rate in the vertical than in the horizontal.

24. The axle suspension system of claim 23 wherein the hangerwise deflection of the elastic means is greater than the beamwise deflection and the spring rate in the vertical is less than in the horizontal.

25. The axle suspension system of claim 24 wherein the pivot connection for resiliently connecting the hanger bracket and the beam includes a retaining pin transverse to the direction of the elongated beam and connected to said hanger bracket, a tubular metal cylinder in which said pin non-rotatably resides and wherein said elastic means comprises an elastic tubular element, the inner surface of which is securely held to said metal cylinder such that substantially all pivotal movement about said pin is within the elastic element.

26. The axle suspension system of claim 22 wherein the pivot connection for resiliently connecting the hanger and beam includes a pivot connection attached to the hanger and said elastic means comprises an element having a different degree of deflection beamwise than hangerwise.

27. The axle suspension system of claim 26 wherein the hanger bracket comprises two transversely spaced plates and said pivot connection for resiliently connecting the beam and the hanger bracket comprises a retaining pin extending between and connected to the plates, said elastomeric element extending around said pin and being of tubular shape, said element being held securely with respect to said pin such that substantially all pivotal movement about said pin is within the elastomeric element.

28. The axle suspension system of claim 27 wherein said tubular elastomeric element is thick walled, and the face of each wall at either end of said element is provided with at least one cavity capable of providing a lesser degree of deflection beamwise than hangerwise in said element.

29. The axle suspension system of claim 28 wherein there are two cavities in each face of said elastomeric element spaced at a vertical distance from said retaining pin thereby to provide a greater degree of deflection hangerwise than beamwise and a greater spring rate in the horizontal than in the vertical direction.