Belt tensioner and method of making the same

In the combination of a vehicle having a bracket means and a tensioner for a power transmission belt of said vehicle that is adapted to be operated in an endless path and drive a plurality of accessories of said vehicle, said tensioner comprising a support means secured to said bracket means so as to be fixed relative to said belt, a belt engaging means carried by said support means and being movable relative thereto, mechanical spring means operatively associated with said support means and said belt engaging means for urging said belt engaging means relative to said support means and against said belt with a force to tension said belt, and fluid dampening means operatively associated with said support means and said belt engaging means to dampen the movement of said belt engaging means relative to said support means in at least one direction of movement thereof, said fluid dampening means comprising a rotary dampening means, said rotary dampening means and said spring means being coaxially aligned, said rotary dampening means comprising an outer ring member and an inner ring member disposed in said outer ring member, said members being arranged for relative rotational movement therebetween, said outer ring member being operatively interconnected to said support means, said inner ring member being operatively interconnected to said belt engaging means, said support means comprising a cup-shaped housing means containing said spring means therein and having a closed end means and an open end means, said housing means being operatively interconnected to said outer ring member, the improvement wherein part of said open end means of said housing means extends over said outer ring member and is secured thereto.

In a method of making a tensioner for a power transmission belt that is adapted to be operated in an endless path, said method comprising the steps of providing a support means for being fixed relative to said belt, providing a belt engaging means to be carried by said support means and be movable relative thereto, operatively associating mechanical spring means with said support means and said belt engaging means for urging said belt engaging means relative to said support means and against said belt with a force to tension said belt, and operatively associating fluid dampening means with said support means and said belt engaging means to dampen the movement of said belt engaging means relative to said support means in at least one direction of movement thereof, forming said fluid dampening means to comprise a rotary dampening means, disposing said rotary dampening means and said spring means to be coaxially aligned, forming said rotary dampening means to comprise an outer ring member and an inner ring member disposed in said outer ring member, arranging said members for relative rotational movement therebetween, operatively interconnecting said outer ring member to said support means, operatively interconnecting said inner ring member to said belt engaging means, forming said support means to comprise a cup-shaped housing means containing said spring means therein and having a closed end means and an open end means, and operatively interconnecting said housing means to said outer ring member, the improvement comprising the steps of extending part of said open end means of said housing means over said outer ring member, and securing said part to said outer ring member.