Abstract: A pilot valve is provided with internal conduits that eliminate the need for all but one exhaust or vent opening in the outer surface of the valve. The pilot vent is directed through a gap between inner and outer tubes so that the fluid flowing through the upper end of the pilot cavity can be directed to the single exhaust port of the valve. The piston cavity vent is similarly connected to the exhaust port through the use of a counterbore cavity formed between a portion of the cavity in which the driving end of the spool member is disposed and a conduit connecting the counterbore cavity to the exhaust port of the valve. In addition, a second exhaust port, if needed for the valve application, is provided completely internal to the surfaces of the valve body and connected via a conduit to the first exhaust port which extends through an outer surface of the valve body.

Abstract: A valve is provided with a throttle member that is capable of metering the flow between a bore channel of the valve and a port extending between the channel and an external location. The throttle member, or metering device, is a partial cylinder formed to include a plurality of deformations in its surface. The deformations can be slots that are shaped to receive a thread of a rotatable threaded member also attached to the valve body of the valve. Rotation of the threaded member can be arranged to cause the throttle member to rotation about the central axis of the channel and edges of the partial cylinder, which are circumferentially spaced apart from each other, can move into interfering relation between the port and the channel to partially block and meter flow therebetween.

Abstract: A valve is provided with a means for determining the operability of the valve without causing it to change fluid conduction state. A spool member is axially moveable within a valve housing in response to pressure changes caused by the plunger of a pilot valve. The plunger is moved in response to an electromagnetic field induced by a solenoid coil. The coil is sequentially actuated at ever increasing intervals of time while the movement of the spool member is monitored by observing an output from a magnetically sensitive device which can be affected by the presence of a permanent magnet within its zone of detection. The permanent magnet is attached for movement with the spool member and the magnetically sensitive device, such as a Hall effect element, is attached to a stationary portion of the valve at a predetermined location.

Abstract: An actuator is provided with a position sensing system which comprises a permanent magnet, a saddle plate, a sole plate and the magnetically sensitive component. The magnet and the magnetically sensitive component are disposed between the saddle plate and the sole plate which are spaced apart for these purposes. A moveable plunger is arranged to move along an axis relative to a stationary stop member. A first magnetic circuit is provide which comprises the permanent magnet, the saddle plate, the sole plate, the stop member and the moveable plunger. A second magnetic circuit is provided which comprises the magnet, the saddle plate, the sole plate and a magnetically sensitive component such as a Hall effect element. In addition, an adjustment means can be provided within the second magnetic circuit to change the reluctance of that circuit for adjustment purposes.

Abstract: A two-stage solenoid valve uses a pair of stacked coaxial armatures separated by a predetermined gap which is maintained by a first spring therebetween. A coaxial connecting rod extends between a first armature and the second armature and is attached to the first armature. A head on the unattached end of the rod bears against a bottom surface of a recess in the second armature to limit the expansion of the first spring. A second spring is arranged to contact the head of the rod and to extend therefrom to a fixed plug in the end of a cylindrical housing surrounding the first and second armatures. The first armature is provided with a fluid sealing surface on a first end for sealing an adjacent fluid port in the valve in response to the spring force exerted by the second spring. A first and a second solenoid coil assembly are coaxially stacked to surround the cylindrical sleeve housing adjacent to respective ones of the first and second armatures.

Abstract: Mounting apparatus for retaining a cylindrical member with respect to a first member by providing a circumferential groove only part way around the cylindrical member to extend through the aperture in the first member and providing an externally threaded clip member having an internal cavity to fit over the end of the cylindrical member with circumferential convex inwardly extending ridges on the clip member fitting within the grooves on the cylindrical member preventing rotation of the clip member and a nut member internally threaded to cooperate with the clip member in holding the cylindrical member within the aperture of the first member.