Valve mechanism for an air operated reciprocating engine

Claim 1

For use in a reciprocating engine, a valve mechanism comprising body means having two inlets, two outlets and two exhaust passages therein, a cylindrical cavity in said body means intersected by said passages, said inlets and outlets being on different sides of said cavity, a cylindrical sleeve valve rotatably slidably fitted into said cavity and having a first series of ports in the wall thereof, a cylindrical spool valve rotatably mounted coaxially inside said sleeve valve and having a plurality of passages therethrough extending generally transversely with respect to the axis thereof, said sleeve and spool valves each having two angularly related operative positions, in one of said positions first and second ones of said ports registers with opposite ends, respectively, of a first one of said spool passages and first ones, respectively of said inlet and outlet passages, none of the other ports register with any other passages for said first position; with said sleeve valve in said first position and said spool valve in said second position a second passage in said spool valve registers at opposite ends with said second port and a third port in said sleeve valve and said second and third ports in turn register with said first outlet passage and a first exhaust passage, none of the other ports and passages being in registry; with said sleeve and spool valves in said second position said first spool passage registers at opposite ends with said first and second sleeve ports which registers in turn with second ones of said inlets and outlets and none of the other ports and passages being in registry; with said sleeve in said second position and said spool in said first position a third passage in said spool registers at opposite ends with said second sleeve port and a fourth sleeve port, said second and fourth sleeve ports also registering, respectively, with said second outlet and the second exhaust passage; with said sleeve in said second position and said spool in said second position said first spool passage registers at opposite ends with said first and second sleeve ports and these in turn register, respectively, with said second inlet and outlet while none of the other spool passages register with any other sleeve port; the first position of said sleeve valve being for forward operation of said engine and the second position for reverse; means for moving each of said sleeve and spool valves individually to the first and second positions thereof; a first engine cylinder having a piston defining a chamber therein, said outlets communicating with the chamber above said piston.