Abstract: In a fluid displacement-type shock absorber, a piston responding to an impacting load moves within a cylinder, forcing hydraulic fluid therein out of one or more orifices into a reservoir. The resistive force of the piston depends upon its velocity, and the area of the orifice or orifices which control the rate at which the fluid can be displaced. The total available orifice are a for discharging fluid from the cylinder is progressively reduced as the piston is displaced from its initial position upon impact. The fixed orifice structure defines successive control regions, each of which is designed to provide a predetermined resistance profile and related deceleration control for a respective load system or mass system. The lightest mass system, traveling at its maximum velocity within the design range, reaches its limiting deceleration rate in the first control region.

Abstract: A spool valve is positioned within the reservoir of a hydraulic shock absorber. The valve body is secured to the pressure tube of the hydraulic cylinder and has openings aligned with ports therein. The spool has threads engaging threads on the valve body so that as the spool is rotated the spool is moved axially to cause the lands on the spool to cover more or less of the openings in the valve body. A rotatable shaft device extends radially through the external housing and into the reservoir. At its inner end the shaft device has a gear which engages a gear on the spool so that as the shaft device is rotated the spool also is rotated.

Abstract: A sleeve is rotatably mounted on the main body and the two define a reservoir cavity therebetween. Projections integral with the body extend radially through the reservoir cavity to contact the inner wall of the sleeve. Spaced axially along the cylinder are a plurality of openings which extend through the projections from the cylinder cavity to the outer end of the projections. On the inner wall of the sleeve in juxtaposition to the outer end of the openings are a plurality of generally annular grooves. The oil path or duct for release of oil from the cylinder cavity to the reservoir cavity when the piston moves inwardly is through the openings and those parts of the grooves at the distal ends of the projections. In one embodiment these grooves vary in cross-sectional size throughout their length. In another embodiment they are helical, at a slight angle to the axis of rotation.

Abstract: A shock absorber having a pressure tube with metering bores defining metering orifices through which fluid is metered upon application of impact forces to a piston assembly slidable in the pressure tube, and an adjustable metering sleeve with ports adjacent the metering orifices for regulating the flow of fluid through the orifices.

Abstract: A shock absorber having passageways through which fluid is metered from a primary chamber upon application of an impact force to a piston assembly slidable in the chamber, and an adjustable flow control member for regulating the flow of fluid through the passageways to an accumulator chamber within the flow control member.

Abstract: A hydraulic dashpot having a pressure tube with a port defining a metering orifice through which fluid is metered upon application of impact forces to a piston assembly slidable in the pressure tube, and wherein the pressure tube is rotatable for adjusting the position of the orifice relative to a spiral valve edge for varying the effective area of the orifice.