Abstract: The invention is a trailing arm suspension with a steerable axle assembly having a caster angle controlling the direction at which the axle steers. A lift axle suspension or a lockout device is provided to lift the wheels from a ground engaging position or to lock the position of the wheels, respectively, permitting the operation of the vehicle in a direction opposite the direction for which the caster angle is designed. Advantageously, the lift axle suspension is of a simplified design and the trailing arm configuration is V-shaped to better absorb lateral forces.

Abstract: A spring brake actuator (14) includes a housing having first (51) and second (52) housing sections defining a housing interior (53). A support plate (70) is movable between retracted and extended positions relative to the housing and a spring (72) is disposed between the second housing section and a first surface of the support plate for biasing the support plate to the extended position. An actuator rod (60) is operably connected to the support plate (70) at a first end for reciprocal movement with the support plate. Another end of the actuator rod extends through an aperture (64) in the first housing section (51). A flexible diaphragm (358) abuts a second surface of the support plate opposite the first surface and divides the interior of the housing into a first chamber and a second chamber. A surface of the diaphragm is exposed to fluid pressure to thereby force the support plate (70) to the retracted position against the bias of the spring (72).

Abstract: A fluid-operated brake actuator having a housing with one or more vent openings in communication with an interior chamber is provided with a filter assembly mounted to the housing over the vent openings.

Abstract: A vehicle suspension comprising first and second arms mountable to a vehicle frame for vertical swinging movement adjacent opposite sides of the vehicle frame, each of which mounts an axle for rotatably supporting at least one ground-engaging wheel thereon. Air springs are mounted between the arms and the frame in load-transmitting relation therebetween. An improved axle lift mechanism for lifting the axles and the at least one wheel responsive to relief of air pressure in the air springs is provided which comprises first and second telescoping guide members mountable to the frame, each of which have a distal end adapted to be positioned adjacent opposing sides of the frame and being movable between a retracted position and an extended position. A first lever mechanism is adapted to be mounted to the frame, and is mounted to the distal end of the first telescoping guide member and to the first arm.

Abstract: Brake actuator housings (120) are provided with mounting studs (105, 125) which are spaced from each other a standard predetermined distance so that smaller brake actuators can be mounted to a bracket (5) on a vehicle by way of the same apertures (108) as larger brake actuators.

Abstract: A variable geometry linkage configuration for use between a support structure and suspended body comprises a link member having first and second ends, a first pivotal interconnection for pivotally interconnecting the first end of the link member with a support plate for rotation about a support pivot axis of rotation. A lever member is provided which has a longitudinal axis and first and second ends. A second pivotal interconnection for pivotally interconnecting the first end of the lever member with an impact plate for rotation about a main pivot axis of rotation. A shock pivot is mounted to the lever member and is adapted to connect an end of a shock absorber to the lever member for rotation about a shock pivot axis of rotation. A third pivotal interconnection is provided for pivotally interconnecting the lever member to the link member for rotation about a lever pivot axis of rotation.

Abstract: A suspension system for a vehicle includes a longitudinally extending frame, an axle connected to the frame for relative movement with respect thereto, an air spring mounted between the frame and the axle to yieldably support the axle with respect to the frame, and upper and lower trailing arms attached to each side of the frame. A first torsion bar extends between and is rigidly attached to the upper trailing arms and a second torsion bar extends between and is rigidly attached to the lower trailing arms. The torsion bar cooperates with the springs during deflection of the suspension system with respect to the frame to thereby yieldably resist relative movement between the trailing arms and the frame. In one embodiment, the upper and lower trailing arms are parallel to each other. This arrangement results in load equalization between the suspension assemblies. Any relative torque caused by deflection of the trailing arms is equally distributed between both torque bars.

Abstract: An anti-creep device for use with an air spring of a tractor-trailer is shown. The anti-creep device includes a support member which is mounted inside the air spring for movement between a blocking position and an articulating position. In the articulating position, the full range of compression between the top plate and piston of the air spring can be exercised. In the blocking position, the support member limits the downward movement of the top plate relative to the piston. Therefore, the support member limits downward movement of the frame rail of the trailer with respect to the axle and trailing arm. The support member can comprise a pivotable plate, a bladder filled with an incompressible fluid, a vertically telescoping arm or upper and lower bumpers rotatable into and out of vertical alignment.

Abstract: A fluid-operated brake actuator having a check valve in the spring chamber to equalize the pressure on opposite sides of an operating movable diaphragm. The check valve being double redundant and tamper resistant and comprising a tubular body having a first one-way valve disposed and one end of the tubular body and a second one-way valve disposed at an opposite end of the tubular body. A support plate is mounted to the tubular body to support the second valve and prevents the easy removal of the check valve from the brake actuator.