A damper assembly has a longitudinal axis and includes a damper housing with a side wall portion and an end wall portion defining a damping chamber containing a quantity of damping fluid. A photon source and a photon receptor are operatively disposed in optical communication with the non-gaseous damping fluid in the damping chamber. The photon source is operable to direct a photon through the non-gaseous damping fluid toward an associated target surface. The photon receptor is operable to receive the photon reflected off the associated target surface through the non-gaseous damping fluid. A sensor suitable for such use as well as spring and damper assemblies and suspension systems are also included.

An end member assembly is dimensioned for securement to an associated flexible spring member. End member assembly includes first, second and third end member sections. First end member section includes a first outer peripheral wall portion. Second end member section includes a second outer peripheral wall portion. Second end member section is positioned in abutting engagement with the first end member section such that a groove extends peripherally around first and second end member sections between first and second outer peripheral wall portions. Third end member section is injection molded in situ with first and second end member sections such that third end member section extends peripherally around first and second end member sections within groove. Gas spring assemblies and vehicle suspension systems are also included.

A combination gas spring and shock absorber apparatus includes a vented gas spring housing and a vented shock absorber housing slidably mounted within the gas spring housing. A shock absorber piston is concentrically mounted within a gas spring piston. A base housing is slidably mounted in the gas spring housing. A shaft extends through the base housing and into the shock absorber housing. The shock absorber piston is mounted in the shock absorber housing on the free end of the shaft. The gas spring piston is mounted in the gas spring housing on the distal end of the base housing. The shock absorber piston is fluidically sealed and slides within the shock absorber housing. The gas spring piston is fluidically sealed and slides along the gas spring housing and the shock absorber housing. The base housing telescopically translates relative to the gas spring housing.

A combination gas spring and shock absorber apparatus includes a vented gas spring housing and a vented shock absorber housing slidably mounted within the gas spring housing. A shock absorber piston is concentrically mounted within a gas spring piston. A base housing is slidably mounted in the gas spring housing. A shaft extends through the base housing and into the shock absorber housing. The shock absorber piston is mounted in the shock absorber housing on the free end of the shaft. The gas spring piston is mounted in the gas spring housing on the distal end of the base housing. The shock absorber piston is fluidically sealed and slides within the shock absorber housing. The gas spring piston is fluidically sealed and slides along the gas spring housing and the shock absorber housing. The base housing telescopically translates relative to the gas spring housing.

A damping air spring for heavy-duty vehicle axle/suspension systems. The damping air spring includes a piston chamber and a bellows chamber and at least one opening between the chambers to provide restricted fluid communication between the chambers. A relationship between a cross-sectional area of the at least one opening in square inches to a volume of the piston chamber in cubic inches to a volume of the bellows chamber in cubic inches to a mean effective area of the air spring in square inches or of the at least one opening in square inches to a volume of the piston chamber in cubic inches to a volume of the bellows chamber in cubic inches to a unitless ratio of the volume of the bellows chamber to the volume of the piston chamber provides damping characteristics to the air spring over a first and second critical range of frequencies.

A damping air spring for heavy-duty vehicle axle/suspension systems. The damping air spring includes a piston chamber and a bellows chamber and at least one opening between the chambers to provide restricted fluid communication between the chambers. A relationship between a cross-sectional area of the at least one opening in square inches to a volume of the piston chamber in cubic inches to a volume of the bellows chamber in cubic inches to a mean effective area of the air spring in square inches or of the at least one opening in square inches to a volume of the piston chamber in cubic inches to a volume of the bellows chamber in cubic inches to a unitless ratio of the volume of the bellows chamber to the volume of the piston chamber provides damping characteristics to the air spring over a first and second critical range of frequencies.

A damping air spring for heavy-duty vehicle axle/suspension systems. The damping air spring includes a first chamber and a second chamber and at least one opening between the first chamber and second chamber to provide restricted fluid communication between the first chamber and the second chamber. An adsorptive material is disposed within the first chamber or the second chamber and works in conjunction with the at least one opening to provide damping characteristics to the air spring over a first and second critical range of frequencies.

A damping air spring for heavy-duty vehicle axle/suspension systems. The damping air spring includes a first chamber and a second chamber and at least one opening between the first chamber and second chamber to provide restricted fluid communication between the first chamber and the second chamber. An adsorptive material is disposed within the first chamber or the second chamber and works in conjunction with the at least one opening to provide damping characteristics to the air spring over a first and second critical range of frequencies.

A hydraulic shock absorber includes a piston, a damper tube, a suspension spring, a plunger, a jack chamber, a pump case, a pump piston, a screw shaft, and a drive unit. Both end surfaces of the pump piston in a reciprocating direction are a first end surface demarcating the pump chamber, and a second end surface demarcating the gas chamber, the second end surface having a screw hole into which the screw shaft is screwed. The pump piston includes a space portion between a bottom plate defining the first end surface and the screw hole. The screw shaft has a through-hole connecting the gas chamber with the space portion.

A hydraulic shock absorber includes a piston, a damper tube, a suspension spring, a plunger, a jack chamber, a pump case, a pump piston, a screw shaft, and a drive unit. Both end surfaces of the pump piston in a reciprocating direction are a first end surface demarcating the pump chamber, and a second end surface demarcating the gas chamber, the second end surface having a screw hole into which the screw shaft is screwed. The pump piston includes a space portion between a bottom plate defining the first end surface and the screw hole. The screw shaft has a through-hole connecting the gas chamber with the space portion.