Abstract: An actual pressure of a fluid having an ambient pressure as part thereof is sensed by a sensor. When the actual pressure decreases below a predetermined pressure, a signal is produced. If desired, the sensor may cause production of the signal when the actual pressure of the fluid exceeds a predetermined pressure.

Abstract: A vehicle suspension system is provided which reduces longitudinal roll tendency in vehicles having a frame, an axle and a suspension system. An auxiliary spring is provided to act against upward bias of the suspension system on the side of the vehicle where the frame is diverging from the axle and is ineffective on the converging side. The normal suspension components resist the roll on the converging side. Collars are also provided to prevent displacement of the torque arm of the suspension system.

Abstract: A flexible joint for use in suspension systems and the like has a rigid cylindrical member, a resilient bushing encompassing the inner member, a split casing having opposed semi-cylindrical surfaces holding the bushing under compression toward the inner member and secured together in bushing-compressing relation, and rigid extrusion barriers preventing compression induced extrusion of the bushing into partings between the casing parts. Configuration of the extrusion barriers complements the compression loading of the resilient bushing by the surfaces of the casing parts.

Abstract: A tandem axle suspension has a bracket supporting a trunnion on which a pair of beams is journaled rockably in side-by-side relation, each beam having first and second arms extending to opposite sides of the trunnion, the first beam arms projecting in opposite directions and having their distal end portions extending along a common axis and each arranged to receive an axle for a wheel located at one side of the common axis, the first beam arms having respective upwardly facing spring supports which are offset toward the opposite side of the common axis, compression springs carried upon the supports being engaged by downwardly facing thrust structure on the second beam arms. Torsional equilibrium is attained in a vertical plane through the axis of the trunnion and about the common axis of the first arms.