Abstract: A selective flow hydraulic gear pump has an integral unit with a front pump section and a rear pump section. The front pump section has a pumping gear set, gear plate, and bearing plate housing. The rear pump section has a pumping gear set, gear plate, and cover housing. The integral unit has an inlet port common to both the bearing plate housing and the cover housing. Check valves and solenoid operated control valves are contained within the bearing plate housing and the cover housing and are associated with a first fluid conduit. A second fluid conduit is in communication with and extends between the bearing plate housing an outlet port in the cover housing.

Abstract: A selective flow hydraulic gear pump has an integral unit with a front pump section and a rear pump section. The front pump section has a pumping gear set, gear plate, and bearing plate housing. The rear pump section has a pumping gear set, gear plate, and cover housing. The integral unit has an inlet port common to both the bearing plate housing and the cover housing. Check valves and solenoid operated control valves are contained within the bearing plate housing and the cover housing and are associated with a first fluid conduit. A second fluid conduit is in communication with and extends between the bearing plate housing an outlet port in the cover housing.

Abstract: A seal construction for a pneumatic valve (66) reduces resistance to movement of a stem (76) which directs flow through the valve. The seals (78) (108) are generally "v" shaped in cross section. The seals include heel portions (86) (110) which are supported on supporting surfaces (80) (112). The seals include first lip portions (92) (122) that extend from the heel portions to a surface that is moveable relative to the seal. Second lip portions (98) (128) extend from the heel portion to surfaces that are stationary relative to the seal. Spaces (104) (134) between radially extending projections (102) (132) and spaces (90) (120) between axially extending projections (88) (118) enable fluid entering pressure relief areas (106) (136) to escape to atmosphere. The seal construction avoids seal deformation that would otherwise increase resistance to stem movement.