Pump having a varying output

Claim 1

In a variable output displacement pump: a casing; a barrel rotatably mounted within said casing, and having a plurality of cylinders therein arranged generally parallel to the axis of rotation of said barrel; means for rotating said barrel; a piston reciprocally received within each of said cylinders, said pistons each having a bore therein extending inwardly from the rear end thereof and terminating in a conical bottom wall; a swash plate received within and journaled to said casing, said swash plate confronting the front ends of said pistons and being tiltable relative to the front face of said barrel; an axial rod received within the bore of each piston, and having a conical head seatable on said conical bore bottom wall; a return spring associated with each axial rod for urging the conical head thereof into engagement with its associated conical bore bottom wall; a generally spherical head on the front end of each of said pIstons; each of said pistons including a lubrication channel leading from the conical bottom of said piston bore to the surface of said spherical head; bearing means carried by said swash plate, said spherical heads being freely received by said bearing means; and an activating member connected with said swash plate and operable for tilting the same.