×

Vehicle suspension

  • US 4,993,729 A
  • Filed: 09/14/1989
  • Issued: 02/19/1991
  • Est. Priority Date: 09/14/1989
  • Status: Expired due to Term
First Claim
Patent Images

1. In an over the highway truck or tractor vehicle having tandem rear axles one of which is a driven axle and the other is a tag axle the improvement comprising:

  • a. at least one driven axle fluid spring and at least one tag axle fluid spring, the springs respectively being interposed between the driven and tag axles and a vehicle frame;

    b. a supply of fluid under pressure;

    c. conduits connecting the supply to the springs;

    d. pressure control means connected to at least one of the conduits for normally maintaining a predetermined pressure ratio between the pressure in the at least one driven axle spring and the at least one tag axle spring; and

    ,e. an operator actuatable traction enhancement control for selectively altering said predetermined ratio to provide a relative increase of the pressure in the at least one driven axle spring relative to the pressure in the at least one tag axle spring.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×