Abstract: The present invention is directed to an actuator piston assembly for use in a rocker arm system. The actuator piston assembly is capable of actuating at least one engine valve during for example engine braking. The actuator piston assembly includes a piston body having a hollow interior, a screw assembly received within the hollow interior of the screw assembly, a biasing assembly for biasing the piston body with respect to the screw assembly, a cap assembly located within the hollow interior, wherein the biasing assembly interacts with the cap assembly and the screw assembly, and a securing assembly for movably securing the piston body to the screw assembly.

Abstract: The present invention is directed to a control value 20 which incorporates the functions of both a shuttle valve and a check valve into a single structure for use in a lost motion engine brake system. In response to a supply of hydraulic fluid from switched low pressure supply circuit 320, control valve body 200 of control value 20 may index within control valve bore 204, such that hydraulic fluid flows through upper annulus 260, first horizontal bore 270, first vertical bore 280, middle annulus 261 and out through lashless fluid supply circuit 340 and accumulator control circuit 350 to acuate engine valve 100. In an embodiment for clipping/rest of the valve actuating piston 130, clipping/reset spool 450 provided in rocker shaft 405. In response to rotational or linear motion, spool annuluses 451 on clipping/reset spool 450 move to open and close clipping reset/passageway 455 and accumulator control circuit 350, thereby providing clipping of piston 130.