Double acting fluid cylinder

Claim 1

A double acting fluid cylinder comprising an elongated cylinder housing having opposite ends, a plug fitted snugly in each end of said housing having an outer end edge and a central recess, a cap disposed at each end of said housing, an end flange on said caps abutted against respective ends of said housing, screw means extending through said flange and engageable with said housing to secure said caps on the housing, a reduced end portion on said caps extending into the recesses of respective plugs, said reduced end portions forming an inwardly directed shoulder on said caps, a resilient sealing ring between the shoulders of said caps and the outer edges of respective plugs, screw means extending through said caps and engageable with respective plugs for securing the caps and plugs together and also to compress said sealing rings for accomplishing a positive seal between said cap and said housing, a pair of ports located at opposite ends of said housing respectively to serve alternately as inlet and outlet ports, a piston assembly slidably mounted in said cylinder housing, means defining a slot extending longitudinally along one side of said housing, an arm on said piston assembly projecting through said slot and arranged to be connected to means to be driven, a flexible strip extending longitudinally of said housing interiorly thereof covering said slot from the inside and sealing the latter on opposite sides of said piston assembly by internal fluid pressure, means defining a groove in said piston assembly slidably engaging said strip, means anchoring one end of said strip to one of said caps, said strip at its end opposite from the anchored end having an aperture therein, and a leaf spring lever secured at one of its ends to the adjacent cap and having its other end engaged in said aperture, said other end extending toward said strip but normally positioned outwardly from said aperture longitudinally of the housing when not engaged in said aperture whereby said spring is flexed when engaged with said aperture and a tensioning force is exerted and maintained on said strip for positive sealing by said strip.