Abstract: An adjustable dashpot mechanism for controlling the rate of return of a spring-biased axially-displaceable shaft, comprising: a tubular housing having portions of unequal diameters therein with rims thereabout a shaft slidably mounted within the housing and extending beyond the ends of the housing, a dashpot piston fixedly mounted to the shaft within the housing and having an adjustable orifice therethrough, a flexible flange disposed between the periphery of the dashpot piston and the housing for effecting fluid sealing engagement therebetween when the dashpot piston is moved away from the smaller diametered portion in the housing and for effecting nonfluid sealing engagement when the dashpot piston is moved towards the smaller diametered portion in the housing, a reservoir piston slidably mounted on the shaft within the housing between the larger diametered portion of the housing and the dashpot piston and a spring disposed between the housing and the reservoir piston for urging the reservoir piston towards