Abstract: A pump-motor apparatus comprising: a pump having an input shaft for receiving motive force to operate the pump, wherein during rotation of the input shaft, the pump exhibits repeating cyclical first torque variations on the input shaft, said first torque variations including cyclical torque peaks and torque dips and occurring in substantially evenly spaced increments in angular position of the input shaft; and an electric drive motor having an output shaft coupled to and driving the input shaft, wherein the electric drive motor exhibits on the output shaft repeating cyclical second torque variations, said second torque variations including cyclical torque peaks and torque dips and occurring in substantially evenly spaced increments in angular position of the output shaft, wherein the substantially evenly spaced increments in angular position of the output shaft are equal to the substantially evenly spaced angular increments in position of the input shaft, wherein torque peaks and dips of the output shaft seco

Abstract: A variable force windshield wiper system for an automobile has a rod which is slidably received within a bore of the drive shaft of the wiper system. The end of the rod contacts a lever arm when the rod extends out from the drive shaft. The lever arm is connected to a spring. The other end of the spring is connected to the windshield wiper arm. As the distance of the rod outside the drive shaft increases, the lever arm rotates about a fulcrum and extends the spring thereby increasing the downward force of the wiper arm toward the windshield. To move the rod, a cam having a threaded exterior surface is mounted on the drive shaft and is attached to the rod. A nut having a threaded interior surface engages the threads of the cam. The nut and cam rotate together if no wiper force change is desired The exterior surface of the nut has ratchet teeth. A pawl is used to selectively engage the ratchet teeth of the nut.

Abstract: A damper includes a piston that carries a relatively compact control valve for controlling fluid flow through the piston. The control valve provides a variable amount of damping by regulating damper fluid flow between the extension chamber and the compression chamber of the damper during extension and compression strokes. Pressure regulation across the piston is controlled through two alternate flow paths as determined by the control valve. Damping through the first flow path is relatively soft and is determined according to the deflective characteristics of a single bi-directional annular disc valve. Damping through the second flow path is relatively firm and is determined by the first bi-directional single annular disc and a second bi-directional single annular disc in series.

Abstract: A damper includes a piston that carries a relatively compact control valve for controlling fluid flow through the piston. The control valve provides a variable amount of damping by regulating damper fluid flow between the extension chamber and the compression chamber of the damper during extension and compression strokes. Pressure regulation across the piston is controlled through two alternate flow paths as determined by the control valve. Damping through the first flow path is relatively soft and is determined according to the deflective characteristics of first and second single bi-directional annular disc valves in parallel. Damping through the second flow path is relatively firm and is determined solely by the second bi-directional single annular disc.