CHAIN TENSIONER PLASTIC BLADE WITH IMPROVED STRUCTURAL RIGIDITY AT THE SPRING-END REACTION SURFACES OF THE BLADE

摘要

A chain tensioner includes a blade assembly operatively connected to a bracket. The blade assembly includes a plastic blade and a spring, with a first spring end located in a first slot and a second spring end located in a second slot. The first spring end contacts a first lower wall at a first contact location and the second spring end contacts a second lower wall at a second contact location. A pivot end spring force vector SFP acts on the first lower wall at the first contact location and a free end spring force vector SFR acts on the second lower wall at the second contact location. A chain is in contact with the outer surface of the blade. The blade assembly is mounted on the bracket with a bracket pin located in the pivot bore and with the foot of the blade supported on a bracket ramp. A pivot pin force vector FP acts on an inside diameter of the pivot bore through the pivot axis. A ramp force vector FR acts on the blade foot at a ramp contact location. The ramp force vector FR and the free end spring force vector SFR are aligned and coincident with each other.

主权项

1. A chain tensioner comprising:
a bracket including a main wall, a ramp that projects outwardly from said main wall, and a pin connected to and projecting outwardly from the main wall; a blade assembly operatively connected to said bracket, said blade assembly comprising: a polymeric blade comprising a first end, a second end, and a central portion that extends between the first end and the second end, said central portion comprising: (i) an outer surface adapted for being slidably engaged by an associated chain; and, (ii) an inner surface located on an opposite side of said central portion relative to said outer surface; a pivot bore defined about a pivot axis in the first end of the blade; a foot located at the second end of the blade; a first spring-receiving slot located in said first end of said blade, said first spring-receiving slot located between said inner surface and a first lower wall that is spaced from said inner surface; a second spring-receiving slot located in said second end of said blade, said second spring-receiving slot located between said inner surface and a second lower wall that is spaced from said inner surface; a spring comprising a first end located in said first spring-receiving slot, a second end located in said second spring-receiving slot, and a central portion located between the first and second spring ends and in contact with said inner surface of said blade central portion; said first end of said spring in contact with said first lower wall at a first contact location and said second end of said spring in contact with said second lower wall at a second contact location such that a pivot end spring force vector SFP acts on said first lower wall at said first contact location and a free end spring force vector SFR acts on said second lower wall at said second contact location; wherein: said tensioner blade assembly is mounted on said bracket with said pin located in the pivot bore and with said foot of said blade supported on said ramp; a pivot pin force vector FP acts on an inside diameter of said pivot bore through said pivot axis; a ramp force vector FR acts on said blade foot at a ramp contact location where said blade foot contacts said ramp; said ramp force vector FR and said free end spring force vector SFR are aligned and coincident with each other.