Patent ID: 7189175

Claim:
An improved hydraulic tensioner ( 1 ) including of a cylinder ( 2 ) having a bore and a pawl hole; a hollow piston ( 3 ) slidably received by the bore and defining a fluid chamber ( 4 ) with the bore having an inner end and an outer end; a spring ( 8 ) biasing the piston ( 3 ) in a protruding direction from the bore, the improvement comprising: a no-return device ( 5 , 7 ) comprising a pawl ( 7 ) received by the pawl hole and rack teeth ( 5 ) along a length of the hollow piston ( 3 ), allowing movement of the piston ( 3 ) in a protruding direction and preventing movement in a retracting direction; and an anti-rotation device ( 6 , 11 , 12 ) comprising a first longitudinal slot ( 6 ) connected to a second slot ( 11 ) at an angle for receiving a pin ( 12 ); wherein when the piston ( 3 ) is fully protruding from the cylinder ( 2 ), the anti-rotation device is disabled and the piston ( 3 ) is disengaged from the no-return device.