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US 4,793,378 AGranted
Interlock valve and control
AssigneeDana Corporation
InventorsJohn M. Loeffler, Rick D. Watson, George F. Schetter
Life of this patent
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AssigneeDana Corporation
InventorsJohn M. Loeffler, Rick D. Watson, George F. Schetter
Estimating the term…
A four way two position interlock air valve adapted to selectively provide air pressure to a servomotor to shift the range section of a transmission. The valve spool is moved by applying pressure to one end thereof while exhausting pressure from the other. The upper side of the spool has a recessed portion within which a valve slide is positioned. The slide is operative to provide communication between a pressurized inlet port and the one of two outlet ports connected to the servomotor depending on the position of the valve spool. The slide is urged upwardly against the inner surface of the valve body by a wave spring. The area of the upper side of the slide is smaller than the area of the lower side thereof and an aperture connects the two sides such that air pressure controlled thereby also urges the slide upwardly against the valve body. The bottom side of the spool has four shoulders formed thereon to interlock with transmission shift rail actuated locking pins at such time as any of said rails is out of its neutral position. When so interlocked, the valve spool cannot be moved.
In a transmission having a fluid pressure actuated means for shifting a range shift section of the transmission and having a plurality of movable shift rails, a valve for selectively connecting an input line communicating with a source of pressurized fluid to one of two output lines communicating with the shifting means for shifting the range shift section comprising:
Dependencies are inferred from the claim text.