Automatically reversing, double acting fluid cylinder mechanism

Claim 1

Automatically reversing, double acting cylinder and piston mechanism comprising, a cylinder, a piston reciprocable in said cylinder, a housing attached to said cylinder, a first bore in said housing, a hollow tubular pilot spool slideable in said bore in said housing, a bushing in each end of said bore of said housing, the ends of said pilot spool being positioned to slide through said bushings, sealing means carried by said bushings for slideable and sealing engagement with the outwardly extending ends of said pilot spool, a threaded rod extending through said pilot spool for slideable movement therein and being connected with said piston for movement therewith, an adjustable locking collar located on said rod on each side of said valve housing for abutment with said pilot spool exteriorally of said housing to cause shifting of said spool in said housing in one direction or the other, a second bore in said housing, a directional spool slideably mounted in said second bore in said housing, a pressure fluid supply passage in said housing and in communication with each of said housing bores, pilot passages in said housing and placing said pilot spool bore in communication with opposite ends of said directional valve bore, passageway means in said housing and communicable (1) with opposite ends of said cylinder, (2) with said directional spool bore and (3) with said supply passage when said directional valve is shifted in opposite positions, and return passageway means in said housing in fluid communication with each end of said pilot spool bore, whereby when said piston moves to one extreme position or the other, said collars shift said pilot spool and consequently shift said directional spool to cause pressure fluid to reverse movement of the piston.