Apparatus for controlling hydraulically operated clutch in vehicle transmission system, including two valves for engaging and disengaging the clutch

A hydraulic control apparatus for controlling a hydraulically operated clutch in a power transmitting system for an automotive vehicle, wherein the clutch is placed in an engaged position by feeding a pressurized fluid supplied from a hydraulic power source into an engaging chamber of the clutch while discharging the fluid from a releasing chamber of the clutch into a drain, and the clutch is placed in a released position by feeding the fluid into the releasing chamber while discharging the fluid from the engaging chamber, said hydraulic control apparatus comprising:

• a two-position clutch control valve having a first position and a second position;
• a two-position rapid clutch release valve having a third position and a fourth position;
• first fluid passage means formed when said clutch control valve and said rapid clutch release valve are placed in said first and third positions, respectively, for feeding said pressurized fluid from said hydraulic pressure source into said releasing chamber of said clutch while discharging the fluid from said engaging chamber of said clutch into said drain, for releasing said clutch at a normal speed;
• second fluid passage means formed when said clutch control valve and said rapid clutch release valve are placed in said second and third positions, respectively, for feeding said pressurized fluid into said engaging chamber while discharging the fluid from said releasing chamber to said drain, for engaging the clutch;
• and
• third fluid passage means formed when said clutch control valve and said rapid clutch release valve are placed in said second and fourth positions, respectively, for feeding said pressurized fluid into said releasing chamber while discharging the fluid from said engaging chamber to said drain, for releasing said clutch at said normal speed,
• whereby said clutch may be released at normal speed when said clutch control valve and said rapid clutch release valve are in either of the first and third positions or the second and fourth positions, respectively.