Patent ID: 8146552

Claim:
A switchable cam follower with a coupling device for a valve train of an internal combustion engine, the cam follower comprises an outer lever with an inner lever extending between arms of the outer lever and also, on a bottom side, a single-end contact for a gas-exchange valve, wherein, on the single-end contact, the levers are pivotable about an axis with a pivoting motion relative to each other, a dome-shaped contact for a support element is located in the outer lever on a crosspiece on the other end and at least one of the levers has a cam run-on surface, and the coupling device comprises a borehole in the outer lever located above the dome-shaped contact, wherein the borehole has a first section of large diameter that starts directly from an outer side of the crosspiece on the other end that extends to a second section of accordingly smaller diameter up to directly before an inner side of the crosspiece, wherein a non-stepped, smooth-cylindrical coupling slide is guided in a sealing manner directly through the second section, the coupling slide projects with a sub-region into the first section, the sub-region is encompassed by at least one compression spring that acts, on one end, against an annular end formed between the first and second sections and, on the other end, against a separate catch element arranged on a lateral surface of the sub-region of the coupling slide, wherein the catch element is a thin-walled sheet-metal cylinder that has, on a pressure space side, a radially outwardly bent collar against which another end of the compression spring acts, wherein the first section of the borehole is closed close to the outer side of the crosspiece by a thin-walled plug, such that a pressure space for hydraulic medium is provided axially between the annular end of the borehole and an inner side of the plug, and, for a coupled case adapted to provide a large valve stroke, the coupling slide can be brought into contact by hydraulic medium that can be guided section by section into the pressure space from the contact before the outer end with a sub-section running close to an inner end with a catch surface of an adjacent cross region of the inner lever and wherein, for a decoupled case to provide a small or 0 valve stroke, the coupling slide is displaceable in a direction toward the plug such that it is out of contact from the catch surface for a switched-off/reduced hydraulic medium pressure by a force of the compression spring.