Abstract: A solenoid valve which includes a valve body having a central bore from which fluid passages radially extend. A valve spool is axially slidably captured within the valve body bore to control passage of fluid among the valve body passages. An electromagnetic variable force motor is mounted on the valve body and includes a housing of ferromagnetic construction with a pole piece of ferromagnetic construction coaxial with the valve spool and surrounded by an electrical coil. An armature comprising a ball of ferromagnetic construction is positioned coaxially with the pole piece in abutting engagement with the valve spool. A coil spring is positioned to engage the ball-armature and to urge the same axially away from the pole piece. The characteristic of magnetic attraction between the ball-armature and the opposing face of the pole piece as a function of separation therebetween is substantially identical with spring rate, both preferably being a linear function of ball-armature displacement.

Abstract: A solenoid valve which includes a valve body having a central bore from which fluid passages radially extend. A valve spool is axially slidably captured within the valve body bore to control passage of fluid among the valve body passages. An electromagnetic variable force motor is mounted on the valve body and includes a housing of ferromagnetic construction with a pole piece of ferromagnetic construction coaxial with the valve spool and surrounded by an electrical coil. An armature comprising a ball of ferromagnetic construction is positioned coaxially with the pole piece in abutting engagement with the valve spool. A coil spring is positioned to engage the ball-armature and to urge the same axially away from the pole piece. The characteristic of magnetic attraction between the ball-armature and the opposing face of the pole piece as a function of separation therebetween is substantially identical with spring rate, both preferably being a linear function of ball-armature displacement.

Abstract: A solenoid valve which includes a valve body having a central bore from which fluid passages radially extend. A valve spool is axially slidably captured within the valve body bore to control passage of fluid among the valve body passages. An electromagnetic variable force motor is mounted on the valve body and includes a housing of ferromagnetic construction with a pole piece of ferromagnetic construction coaxial with the valve spool and surrounded by an electrical coil. An armature comprising a ball of ferromagnetic construction is positioned coaxially with the pole piece in abutting engagement with the valve spool. A coil spring is positioned to engage the ball-armature and to urge the same axially away from the pole piece. The characteristic of magnetic attraction between the ball-armature and the opposing face of the pole piece as a function of separation therebetween is substantially identical with spring rate, both preferably being a linear function of ball-armature displacement.

Abstract: A solenoid valve which includes a valve body having a central bore from which fluid passages radially extend. A valve spool is axially slidably captured within the valve body bore to control passage of fluid among the valve body passages. An electromagnetic variable force motor is mounted on the valve body and includes a housing of ferromagnetic construction with a pole piece of ferromagnetic construction coaxial with the valve spool and surrounded by an electrical coil. An armature comprising a ball of ferromagnetic construction is positioned coaxially with the pole piece in abutting engagement with the valve spool. A coil spring is positioned to engage the ball-armature and to urge the same axially away from the pole piece. The characteristic of magnetic attraction between the ball-armature and the opposing face of the pole piece as a function of separation therebetween is substantially identical with spring rate, both preferably being a linear function of ball-armature displacement.

Abstract: A parted annular piston sealing ring and a method for manufacture thereof wherein an inwardly facing ring surface adapted to be engaged by an expander-spring for expanding the ring into sealing engagement with a cylinder wall is hardened in a zone immediately adjacent the parted ring tips. Hardening of the spring-engaging surface at the ring tips reduces wear and embedment between the ring and spring in the region of the ring gap while permitting resilient flexure of the ring in regions removed from the ring gap to follow surface variations in a cylinder wall.

Abstract: A parted annular piston sealing ring and a method for manufacture thereof wherein an inwardly facing ring surface adapted to be engaged by an expander-spring for expanding the ring into sealing engagement with a cylinder wall is hardened in a zone immediately adjacent the parted ring tips. Hardening of the spring-engaging surface at the ring tips reduces wear and embedment between the ring and spring in the region of the ring gap while permitting resilient flexure of the ring in regions removed from the ring gap to follow surface variations in a cylinder wall.