Central hydraulic system for a vehicle

Claim 2

In a fluid supply system for a vehicle having an automatic transmission and also power steering, the combination of a power steering system; a transmission control system; a pump for delivering fluid under pressure; fluid passage means for operatively connecTing said power steering system and said transmission control system in series, and alternatively in parallel, to receive the fluid from said pump, switching valve means in said passage means for preventing fluid flow from one of said systems to said pump when said systems are connected in series and for permitting fluid flow from said one system to said pump when said systems are connected in parallel; and check valve means in said passage means for permitting fluid flow from said one system to the other when said switching valve means prevents fluid flow from said one system to said pump and for preventing flow in the opposite direction when said switching valve means permits fluid flow from said one system to said pump.

Claim 3

In a fluid supply system for a vehicle having an automatic transmission and power steering, the combination of a pump for supplying fluid under pressure; a transmission control system that returns fluid to said pump; a power steering system; flow control valve means for providing a controlled amount of fluid delivery from said pump to said power steering system and delivering any excess fluid to said transmission control system; check valve means for permitting fluid flow from said power steering system to said transmission control system while preventing flow in the opposite direction; and switching valve means for selectively permitting and preventing fluid flow from said power steering system to said pump.

Claim 4

In a fluid supply system for a vehicle having an automatic transmission and power steering, the combination of a pump for supplying fluid under pressure; a transmission control system that returns fluid to said pump; a power steering system; flow control valve means for providing a controlled amount of fluid delivery from said pump to said power steering system and delivering any excess fluid to said transmission control system; check valve means for permitting fluid flow from said power steering system to said transmission control system while preventing flow in the opposite direction; and switching valve means for selectively permitting and preventing fluid flow from said power steering system to said pump.

Claim 5

In a fluid supply system for a vehicle having an automatic transmission and power steering, the combination of a pump for supplying fluid under pressure; a transmission control system that returns fluid to said pump; a power steering system; flow control valve means for providing a controlled amount of fluid delivery from said pump to said power steering system and delivering any excess fluid to said transmission control system; check valve means for permitting fluid flow from said power steering system to said transmission control system while preventing flow in the opposite direction, switching valve means for selectively permitting and preventing fluid flow from said power steering system to said pump; and pressure balance valve means for maintaining the pressure of the fluid from said pump at a value higher than the pressure in said transmission control system.

Claim 6

In a fluid supply system for a vehicle having an automatic transmission and power steering, the combination of a pump for supplying fluid under pressure; a transmission control system that returns fluid to said pump; a power steering system; flow control valve means for providing a controlled amount of fluid delivery from said pump to said power steering system and delivering any excess fluid to said transmission control system; check valve means for permitting fluid flow from said power steering system to said transmission control system while preventing flow in the opposite direction, switching valve means for selectively permitting and preventing fluid flow from said power steering system to said pump; and pressure balance valve means for maintaining the pressure of the fluid from said pump at a value higher than the pressure in said transmission control system.

Claim 7

In a fluid supply system for a vehicle having an automatic transmission and power steering, the combination of a pump for supplying fluid under pressure; a transmission control system including first passage means for delivering fluid pressure for transmission control, second passage means for returning fluid to said pump, and pressure regulator valve means for regulating fluid pressure in said first passage means and delivering any excess fluid to said second passage means; a power steering system; third passage means for delivering fluid from said pump to said power steering system; flow control valve means in said third passage means for controlling the amount of fluid delivered from said pump to said power steering system and delivering any excess fluid to said first passage means; fourth passage means for delivering fluid from said power steering system; check valve means for permitting fluid flow from said fourth passage means to said first passage means while preventing flow in the opposite direction; and switching valve means for blocking said fourth passage means from said second passage means whereby said power steering system and said transmission control system are connected in series to said pump with said transmission control system receiving excess fluid from said flow control valve means and also for connecting said fourth passage means to said second passage means whereby said power steering system and said transmission control system are connected in parallel to said pump.

Claim 8

In a fluid supply system for a vehicle having an automatic transmission and power steering, the combination of a pump for supplying fluid under pressure; a transmission control system including first passage means for delivering fluid pressure for transmission control, second passage means for returning fluid to said pump, and pressure regulator valve means for regulating fluid pressure in said first passage means and delivering any excess fluid to said second passage means; a power steering system; third passage means for delivering fluid from said pump to said power steering system; flow control valve means in said third passage means for controlling the amount of fluid delivered from said pump to said power steering system and delivering any excess fluid to said first passage means; fourth passage means for delivering fluid from said power steering system; check valve means for permitting fluid flow from said fourth passage means to said first passage means while preventing flow in the opposite direction; and switching valve means for blocking said fourth passage means from said second passage means whereby said power steering system and said transmission control system are connected in series to said pump with said transmission control system receiving excess fluid from said flow control valve means and also for connecting said fourth passage means to said second passage means whereby said power steering system and said transmission control system are connected in parallel to said pump.

Claim 9

In a fluid supply system for a vehicle having an automatic transmission and power steering, the combination of a pump for supplying fluid under pressure; a transmission conTrol system including first passage means for delivering fluid pressure for transmission control, second passage means for returning fluid to said pump, and pressure regulator valve means for regulating fluid pressure in said first passage means and delivering any excess fluid to said second passage means; a power steering system; third passage means for delivering fluid from said pump to said power steering system; flow control valve means in said third passage means for controlling the amount of fluid delivered from said pump to said power steering system and delivering any excess fluid to said first passage means; fourth passage means for delivering fluid from said power steering system; check valve means for permitting fluid flow from said fourth passage means to said first passage means while preventing flow in the opposite direction; switching valve means for blocking said fourth passage means form said second passage means whereby said power steering system and said transmission control system are connected in series to said pump with said transmission control system receiving excess fluid from said flow control valve means and also for connecting said fourth passage means to said second passage means whereby said power steering system and said transmission control system are connected in parallel to said pump; and pressure balance valve means responsive to both the regulated pressure in said first passage means and the pressure in said third passage means for maintaining the pressure of the fluid delivered by said pump above that of the regulated pressure in said first passage means when said power steering system and said transmission control set are connected in parallel to said pump.

Claim 10

In a fluid supply system for a vehicle having an automatic transmission and power steering, the combination of a pump for supplying fluid under pressure; a transmission conTrol system including first passage means for delivering fluid pressure for transmission control, second passage means for returning fluid to said pump, and pressure regulator valve means for regulating fluid pressure in said first passage means and delivering any excess fluid to said second passage means; a power steering system; third passage means for delivering fluid from said pump to said power steering system; flow control valve means in said third passage means for controlling the amount of fluid delivered from said pump to said power steering system and delivering any excess fluid to said first passage means; fourth passage means for delivering fluid from said power steering system; check valve means for permitting fluid flow from said fourth passage means to said first passage means while preventing flow in the opposite direction; switching valve means for blocking said fourth passage means form said second passage means whereby said power steering system and said transmission control system are connected in series to said pump with said transmission control system receiving excess fluid from said flow control valve means and also for connecting said fourth passage means to said second passage means whereby said power steering system and said transmission control system are connected in parallel to said pump; and pressure balance valve means responsive to both the regulated pressure in said first passage means and the pressure in said third passage means for maintaining the pressure of the fluid delivered by said pump above that of the regulated pressure in said first passage means when said power steering system and said transmission control set are connected in parallel to said pump.