Patent ID: 7048662

Claim:
A cartridge tensioner for transmission belts or chains comprising: a) a cylinder comprising a cylinder bore; b) a piston slidably received in the cylinder bore and provided with a piston bore; c) a vent device slidable in the piston bore, comprising an end part and a stem, wherein the stem extends from the end part; d) a pressure spring acting between a shoulder of the cylinder and the end part of the vent device; and e) a retaining device for the vent device, accessible from the outside of the cylinder; wherein the retaining device is in an engagement position with the stem of the vent device to prevent the pressure spring from acting on the piston; and wherein the retaining device is in a disengagement position with the stem of the vent device to allow the pressure spring to bias the vent device against the piston and to act consequently on the piston.