An improved double-acting fluid cylinder with primary and secondary chambers of tandem construction, wherein the primary chamber is utilized to provide ram motion in a first direction and wherein the tandemly arranged secondary chamber is provided with a single biasing spring means to resiliently bias the secondary piston and to buffer and control the rate of motion induced in the ram, and also to drive the ram in a direction opposite the stroke of the first direction and at a time subsequent to the stroke so as to temper the ultimate amplitude or extent of motion induced in the ram in response to forces applied within the primary chamber.