Patent ID: 6994644
Filing Date: 2006-02-07
Classification: F16H

Abstract:
1. A tensioner comprising: a housing having a front end, and a plunger-receiving hole formed in said housing, said hole having an opening at said front end of the housing, and said hole having a plunger-receiving part having a first diameter spaced from said front end of the housing and a widened part adjacent said front end of the housing, said widened part having a diameter wider than said first diameter and a shoulder recessed from said front end and facing toward said front end; a plunger having a longitudinal axis and slidably fitting into said plunger-receiving hole and protruding axially from the opening thereof in a protruding direction, said plunger having an external surface with longitudinally extending, toothed racks formed thereon; a protrusion biasing spring, biasing said plunger in said protruding direction; a cam-receiving ring, through which the plunger extends, the cam-receiving ring being located in said widened part of the hole, and having an oblique cam-guiding surface, said guiding surface sloping in the direction of protrusion of the plunger and outward from the axis of the plunger; a ring-biasing spring, biasing said cam-receiving ring in the direction of protrusion of the plunger; a plurality of wedge-shaped cams, which slide on the oblique cam-guiding surface of the cam-receiving ring, and engageable with the racks on said plunger; a cam-biasing spring, biasing said wedge-shaped cams in the direction opposite to said direction of protrusion of the plunger; and a seal cap on said housing, the seal cap having a cap opening through which the plunger extends axially, and cooperating with said widened portion of said hole to provide an enclosure containing said ring-biasing spring, said cam-receiving ring, said wedge-shaped cams, and said cam biasing spring, said seal cap having an inside end surface surrounding said cap opening; wherein said cam-receiving ring is disposed between said inside end surface of said seal cap and said shoulder, and movable axially therebetween.