Temperature responsive fan drive coupling

Claim 1

A temperature controlled fluid coupling adapted to couple a radiator cooling fan of an internal combustion engine to the engine to thereby rotate the fan, the fluid coupling being of the type including a housing having a drive chamber into which a rotor both extends and is positioned, a shear liquid reservoir chamber in the housing, the reservoir chamber communicating with the drive chamber through a temperature controlled valve, the amount of valve opening determining the degree of rotary coupling between the engine and the fan, the valve in one position establishing maximum rotary coupling, a bi-metal laminate mounted on the housing and actuating the valve, bowing of the bi-metal laminate in one direction due to changes in its ambient temperature causing the valve to open and bowing of the laminate in the opposite manner causing the valve to close, the improvement comprising, means for mounting the bi-metal laminate on the housing in a desired, predetermined orientation relative to the valve, whereby mounting of the bi-metal laminate on the housing is possible only when the bi-metal is oriented with respect to the housing in the predetermined manner.