Automatic chain tensioner
AssigneeOntario Drive & Gear Limited
InventorsBrian Mark Cressman, Kevin Donald Buschert
Life of this patent
Estimating the term…
Abstract
The drive-chain tensioner is automatically self-adjusting. A chain-slipper is guided to follow wear-movement of the chain. A cam is mounted on the follower. If slack in the chain increases, the cam is rotated by a cam spring to a position in which a larger radius of the cam lies under the follower. The cam provides a solid abutment that prevents the chain from compressing the tensioning springs and becoming slack when drive is reversed. For compactness and good load distribution, the chain is supported on a saddle between two cams. The cams have ratchet teeth.
Claims27
An automatically self-adjusting drive tensioner apparatus, in combination, with a tensile drive-means wherein:
- the tensile drive-means undergoes occasional drive-direction reversal, of a drive-direction in that a first run of the drive-means, the drive-run, is under drive-tension, and an other run of the drive-means;
- termed the return-run, is under return-tension, and when the drive-direction is reversed, the second run becomes the drive-run, the first run hereby becoming the return-run;
- the apparatus includes a follower, which is arranged for direct contact with a tensile-drive-component of the tensile-drive means;
- the tensile-drive means includes a frame component;
- the apparatus includes an adjustable-length strut-assembly;
- the configuration of the apparatus is such that, during the drive-direction reversal, a component of the tension force in the tensile-drive-component is transmitted to the follower, and is transmitted therefrom to the frame component, in a load-line which includes the strut-assembly;
- the apparatus includes a follower-guide-means, for guiding the follower for. movement in a direction to take up slack in the tensile-drive-component due to wear thereof;
- the strut-assembly engages the follower at a strut/follower point, and engages the frame component at a strut/frame point, and lies in position between the two points;
- the strut-assembly includes an operable adjuster-means, which is effective, when operated, to elongate the strut-adjuster, responsive to a net force on the strut-assembly, between the two points, being in a direction to urge the points apart;
- the strut-assembly is so structured that the strut-assembly becomes solid, in that the points are held apart by the strut-assembly in a fixed-distance relationship, responsive to the net force on the strut-assembly, between the two points, being in the direction to urge the points together.
Dependencies are inferred from the claim text.