Hydraulic control system for transmission and the like

Claim 1

A HYDRAULIC CONTROL SYSTEM, COMPRISING: A PUMP; AN ACCUMULATOR; A PAIR OF ALTERNATELY PRESSURIZIBLE MOTORS; SELECTOR VALVE MEANS INCLUDING A HOUSING HAVING INLET MEANS, A PAIR OF MOTOR PORTS CONNECTED RESPECTIVELY TO THE MOTORS A DRAIN PORT, AND A SELECTOR VALVE SHIFTABLE IN A FIRST RANGE INCLUDING FIRST AND SECOND ACTIVE POSITIONS FLANKING A FIRST NEUTRAL POSITION AND IN A SQUENTIALLY RELATED SECOND RANGE INCLUDING THIRD AND FOURTH ACTIVE POSITIONS FLANKING A SECOND NEUTRAL POSITION, SAID SELECTOR VALVE IN ANY ACTIVE POSITION CONNECTING THE MOTOR PARTS ALTERNATELY TO THE INLET MEANS AND TO THE DRAIN PORT AND IN BOTH NEUTRAL POSITIONS DISCONNECTING THE MOTOR PORTS FROM THE INLET MEANS AND CONNECTING THEM TO THE DRAIN PORT; AN ACCUMULATOR LINE CONNECTING THE PUMP TO THE INLET MEANS; A METERING VALVE IN THE PUMP LINE UPSTREAM OF THE CONNECTION OF THE ACCUMULATOR LINE TO THE INLET MEANS AND OPERATIVE IN A FIRST CONDITION TO RESTRICT FLUID FLOW THROUGH THE PUMP LINE AND IN A SECOND CONDITION TO PROVIDE FOR RELATIVELY FREE FLOW THROUGH SAID PUMP LINE; MEANS BIASING THE METERING VALVE TO ITS FIRST CONDITION; HYDRAULIC MEANS RESPONSIVE TO PUMP LINE PRESSURE UPSTREAM OF THE METERING VALVE AND ACTING ON THE METERING VALVE TO INCUR THE SECOND CONDITION THEREOF, SAID HYDRAULIC MEANS INCLUDING A FLUID-PRESSURE-RECEIVABLE CHAMBER HAVING AN OUTLET; A REGULATING VALVE BIASED TO A CLOSED POSITION FOR CLOSING THE OUTLET SO AS TO CAPACITATE SAID HYDRAULIC MEANS TO INCUR SAID SECOND CONDITION OF THE METERING VALVE WHEN THE PUMP LINE IS PRESSURIZED, AND SAID REGULATING VALVE BEING MOVABLE TO A BLEED POSITION AND TO A DUMP POSITION RELATIVE TO SAID OUTLET TO PROVIDE RESPECTIVELY SLOW AND FAST ESCAPE OF FLUID FROM THE CHAMBER AND THUS TO REGULATE THE RATE OF BIASED RETURN OF THE METERING VALVE TO ITS FIRST CONDITION; AND ACTUATING MEANS OPERATIVE BETWEEN THE SELECTOR VALVE AND THE REGULATING VALVE FOR INCURRING THE CLOSED, BLEED AND DUMP POSITIONS OF THE REGULATING VALVE RESPECTIVELY ACCORDING TO THE ACTIVE, FIRST NEUTRAL AND SECOND NEUTRAL POSITIONS OF THE SELECTOR VALVE.