Abstract

A cartridge type hydraulic tensioner for a chain or belt is described comprising a cylinder (11) with an inner bore (13) and a hollow piston (12) sliding in the cylinder and biased outward by an elastic elements and by pressurized fluid fed into said bore (13), at least one rack (20) being formed on the skirt of the piston (12) and engaged by a toothed pad (21) passing through a corresponding aperture (22) formed in the wall of the cylinder and biased against the rack by an annular spring (25) housed in an annular seat (24) formed in the skirt of the cylinder (11) without protruding from the bulk of the cylinder.