Patent ID: 8348791

Claim:
A tensioner comprising: a base having a first recess portion, a second recess portion, a third recess portion, and a fourth recess portion on surfaces of the base, wherein the fourth recess portion vertically connects the third recess portion with the second recess portion, and a central axis of the first recess portion, a central axis of the second recess portion, and a central axis of the third recess portion are parallel to one another; a first flexible device disposed in the first recess portion; a piston disposed in the first recess portion and contacting the first flexible device, wherein the piston has a first ending protruding outside the first recess portion; a rack disposed in the second recess portion and having a second ending protruding outside the second recess portion, wherein the second ending extends and connects to the first ending of the piston so that the piston can drive the rack; a stopping device axially disposed in the fourth recess portion, and having a third ending and a fourth ending, wherein a work surface is disposed on one side of the third ending, a first connecting surface is disposed on one side of the fourth ending, a first sticking portion and a second sticking portion are disposed on two opposite edges of the first connecting surface, and a turning mechanism for turning the stopping device is disposed on the fourth ending; and a second flexible device disposed in the third recess portion and contacting the third ending of the stopping device; wherein as the first sticking portion meshes to the teeth of the rack, the second flexible device contacts the work surface of the third ending, and the first flexible device pushes the piston away from the first recess portion; wherein as the second sticking portion meshes with the teeth of the rack, the first flexible device cannot push the piston away from the first recess portion.