Triple action damper for hydraulic clutch actuator

A damper (36) for use in a hydraulic actuator system between a master cylinder (10) and a slave cylinder (12) of the system. The damper includes a housing (44), an elastomeric diaphragm (46) and a spring steel diaphragm (48). The upper face (46c) of the elastomeric diaphragm (46) is in fluid communication with hydraulic fluid in the system via a port (52c) so that the elastomeric diaphragm may deflect in response to low frequency vibrations transmitted through hydraulic fluid in the system to effect damping of the low frequency vibrations. The spring steel diaphragm (48) is positioned in the system generally parallel to and proximate the lower face (46d) of the elastomeric diaphragm (46) so as to form a back up for the elastomeric diaphragm so that the elastomeric diaphragm may deform against the spring steel diaphragm in response to intermediate frequency vibrations transmitted through the hydraulic fluid to cause deflection of the spring steel diaphragm to effect damping of the intermediate frequency vibrations. A thin annular sidewall (52a) of the damper housing (44) coacts with the upper face (46c) of the elastomeric diaphragm (46) which provides further high frequency system damping by virtue of vibratory volumetric expansion of the thin housing sidewall (52a).