Adjustable tensioner
An adjustable tensioner with a base, a pivot-arm that oscillates about a pivot secured to the base, a pulley attached to the pivot-arm, a compression spring with a first end operatively connected to the pivot-arm and a second end operatively connected to a shoe that presses a convex surface of the shoe against a concave arcuate surface of the pivot-arm, to the shoe held in place against a protuberance secured to the base by a balance of forces. An adjustment feature allows setting a base position with respect to an indicated predetermined belt spring force.
1. An adjustable tensioner comprising:
a base;
a pivot-arm that oscillates about a pivot secured to the base;
a pulley attached to the pivot-arm and for engaging the belt;
a compression spring with a first and operatively connected to the pivot-arm at an operative radius in relation to the pivot;
and a damping mechanism that inhibits oscillatory movements of the pivot-arm;
the pivot-arm comprising a concave arcuate surface that moves with the pivot-arm and is spaced a distance from the pivot, the concave arcuate surface oriented to generally face the pivot and a second end of the compression spring;
the damping mechanism comprising a moveable shoe with a convex arcuate friction surface complimentary to and engaging the concave arcuate surface of the pivot-arm, a spring receiving portion that faces and attaches to a second end of the spring, and a surface portion that engages a protuberance secured to the base, the spring applying a spring force against the shoe pressing the convex arcuate surface against the concave surface generating a reactionary force to the shoe, the spring force and reactionary force combining to press the shoe against the protuberance, the improvement comprising;
an adjustment portion extending from the base comprising a tool receiving portion;
an indicator portion on the pivot-arm;
an indicator portion disposed on the base to cooperate with the indicator portion on the pivot-arm for indicating a predetermined compression spring force.
2. The tensioner as claimed in claim 1 wherein the surface portion of the damping shoe and the protuberance are in the form of complimentary ramp surfaces oriented in the direction of a divergent angle in relation to a longitudinal axis of the compression spring.
3. The tensioner as claimed in claim 1 where the concave arcuate surface of the, pivot-arm is substantially concentric with the pivot.
4. The tensioner as in claim 1 wherein the tool receiving portion further describes a hole.
5. The tensioner as in claim 1 wherein the tool receiving portion radially extends beyond the damping mechanism with respect to the pivot.