Temperature responsive fan clutch for vehicle engine

Claim 1

A temperature responsive clutch for the radiator cooling fan of a motor vehicle engine, comprising: a shaft to be attached to the fan mounting of said engine, a housing rotatably mounted on said shaft by bearing means, said housing having means for mounting a fan, said housing comprising a front housing plate and a rear housing plate attached together to form an enclosed chamber for holding a viscous fluid, a rear inner plate fixedly attached to said shaft within said chamber, a front inner plate located in said chamber and coupled to said front housing plate for rotation there with and for axial movement relative to said front housing plate and said rear inner plate, said front inner plate having spaced apart apertures formed therethrough at positions spaced from the axis thereof, a spring mounting member having legs extending through said apertures and connected to said front housing plate, and further having inside structure between said legs, spring means located between the legs of said spring mounting member and having one end in engagement with the inside structure of said spring mounting member and the other end in engagement with the rear side of the center portion of said front inner plate betwen said apertures for urging said front inner plate away from said rear inner plate, and temperature responsive means supported by said front housing plate and having a moveable element located within said chamber for engaging and moving said front inner plate toward said rear inner plate when the temperature increases to a high level whereby said front inner plate and, hence, said housing are rotated due to the shear force of said viscous fluid between said rear and front inner plates.