Patent ID: 8037857

Claim:
A hydraulic support element for a switchable cam follower of a valve drive of an internal combustion engine, comprising: an elongated housing having an elongated blind bore therein, forming a base at one end of the housing and an opening at another end of the housing; a pressure piston arranged in the bore of the housing and extending longitudinally from the opening of the housing, the piston having an underside at one end which opposes the base of the housing and a head at another end of the piston, which projects beyond the opening of the housing; a first reservoir space in the pressure piston, located adjacent the underside of the piston; a second reservoir space formed in the pressure piston axially above the first reservoir space and extending to the head of the pressure piston; a high pressure space located between the base of the housing and the underside of the pressure piston; a non-return valve arranged on the underside of the pressure piston providing fluid communication between the first reservoir and the high pressure space; a first fluid passage in the housing extending from outside the housing into the bore; a first fluid passage in the pressure piston, the first passage in the piston in fluid communication with the first passage in the housing and the first reservoir space in the piston; a second passage in the housing extending from outside the housing into the bore; a second passage in the pressure piston, the second passage in the piston in fluid communication with the second passage in the housing and the second reservoir space in the piston; and a ball partially surrounded and supported by an internal wall of the pressure piston and separating the first reservoir space from the second reservoir space.