초록 ▼

In the case of pump failure a spool valve instantly connects a pressurized fluid accumulator with the servo motor which assistingly activates the master cylinder and isolates a power steering mechanism fluidly connected to the servo motor so that only the power brake is temporarily operable but with

In the case of pump failure a spool valve instantly connects a pressurized fluid accumulator with the servo motor which assistingly activates the master cylinder and isolates a power steering mechanism fluidly connected to the servo motor so that only the power brake is temporarily operable but with stepwise decreasing effectiveness.

대표청구항 ▼

In a hydraulic system; a first source of hydraulic fluid under pressure; a second source of hydraulic fluid under pressure; a hydraulically operable device; a valve body formed with first passage means extending between a first inlet port and a first outlet port, second passage means extending betwe

In a hydraulic system; a first source of hydraulic fluid under pressure; a second source of hydraulic fluid under pressure; a hydraulically operable device; a valve body formed with first passage means extending between a first inlet port and a first outlet port, second passage means extending betweeN a second inlet port and said first outlet port, said first outlet port communicating with said hydraulically operable device, said first inlet port communicating with said first source and said second inlet port communicating with said second source, and a bore arranged to intersect said first passage means and said second passage means; a spool valve reciprocally received in said bore and axially movable between first and second positions, said spool valve being so constructed and arranged that, in said first position thereof said first passage means is open to permit fluid communication between said first inlet port and said first outlet port and said second passage means is closed to fluidly isolate said second inlet port and said first outlet port, while in said second position of said spool valve said first passage means is closed and said second passage means is open; spring means for biasing said spool valve toward said second position; and chamber means communicating with said first source for biasing said spool valve against the bias of said spring means toward said first position thereof in response to the supply of fluid under pressure from said first source into said chamber means.