Abstract: An active suspension system for a vehicle employing fluid powered force exertion units between the wheels and the vehicle body. The vehicle's engine operates a pump which provides pressurized fluid to operate the force exertion units under the control of a processing unit which monitors the rate of change of the power being consumed by the force exerting units and stores demand data indicative of the prior history of power demands placed on the engine by the suspension system. The processor calculates an autoregression moving average of the stored past demand values to form a prediction of future demand, thereby controlling the amount of power delivered by the engine in anticipation of the predicted needs of the force exertion units.

Abstract: An active suspension system for a vehicle having sprung and unsprung masses including a powered source of pressurized fluid coupled to a processor. The processor calculates the rate of change of the power being consumed by the source and controls that rate of change whenever the calculated rate exceeds a predetermined value.

Abstract: A vehicle suspension system having active and passive modes, comprising fluid providing means for providing a pressurized fluid, a cylinder, having at least two chambers, protection valve means having first and second states, for coupling the fluid providing means to the cylinder in the first state and uncoupling the fluid providing means from the cylinder in the second state, and by-pass valve means, having at least first and second states, being fluidly coupled to the cylinder and the protection valve means, for providing fluid communication therethrough between the chambers in the second state and not providing fluid communication therethrough between the chambers in the first state, and wherein the protection valve means is in the first state when the suspension system is in the active mode and the protection valve means and the by-pass valve means are in the second state when in the passive mode.

Abstract: A die for use in extruding helical gears includes a die orifice at the upper end of the die teeth where the extrusion blank first enters the die. Each tooth is formed with a land directed parallel to the helix on the drive and trail side of the tooth and an end face perpendicular to the helix that intersects either a transition surface, directed perpendicular to the die axis, or a land. Alternatively, the end face can extend entirely across the tooth width from one land to the other without the use of the transition surface. Relief surfaces slope inwardly from the land and provide spaces within which the extrusion blank may expand without undue frictional contact with the die.

Abstract: A method and tool for making an extrusion die wherein the extrusion has a lobed helical outer contour. An electrical discharge machining electrode has an identical outer contour. Mounted integrally with the electrode is a lead bar having a guide recess that makes a second helix angle with respect to the axis of the electrode. A guide pin fixedly mounted with respect to the moving assembly is located within the recess. Axial movement and rotation of the electrode through the die blank is controlled by the pin and recess.

Abstract: A sleeve having a tapered outer surface is shrink or interference fitted over the outer surface of a die blank in which is formed a central bore, a larger diameter bore and a transition bore therebetween. The diametrical interference between the sleeve and the die blank is effective in producing an elastic deformation of the smaller diameter bore causing it to assume a conical shape. The die blank and sleeve are restrained within a casing and the inner surface of the die is formed by electrical discharge machining, electrical chemical machining or by other known methods. The die casing and sleeve are removed from the die, allowing the release of the stored strain energy of deformation which causes the smaller bore of the die to assume a conical shape tapering radially outwardly from its inner extremity. The sharp corner that results at the innermost end of the smaller bore is removed by lapping a straight-sided tool through the central opening of the die.