Tensioner

1. A tensioner comprising:

a base having a toothed portion;

a pivot arm pivotally engaged with the base;

a pulley journalled to the pivot arm;

a spring disposed between the base and the pivot arm for biasing the pivot arm in a first direction;

a mechanism disposed on the pivot arm and engaged with the base, the mechanism comprising a rotatable geared member and a second spring engaged between the rotatable geared member and the pivot arm, the second spring biasing the pivot arm in the first direction; and

the rotatable geared member having a non-toothed portion such that the non-toothed portion can engage with the toothed portion to prevent rotation of the pivot arm in a reverse direction from the first direction.

2. The tensioner as in claim 1 , wherein the toothed portion further comprises an arcuate shape.

3. The tensioner as in claim 1 further comprising a removable member for temporarily fixing a rotatable geared member position with respect to the toothed portion.

4. The tensioner as in claim 3 , wherein the removable member temporarily fixes a pivot arm position with respect to the base.

5. The tensioner as in claim 1 wherein the rotatable geared member comprises teeth on a circumferential portion having an angular span of approximately 90°.

6. The tensioner as in claim 1 further comprising a means to prevent debris from entering the tensioner.

7. The tensioner as in claim 1 , wherein the rotatable geared member is rotatable by a tool engageable therewith.