| 摘要 |
1,221,119. Change-speed control. ZAHNBADFABRIK FRIEDRICHSHAFEN A.G. 27 Aug., 1968 [12 Sept., 1967], No. 40848/68. Heading F2D. In a gear shift mechanism the ratio-establishing clutches or brakes I, II ... are operated by a single fluid pressure control valve 2 mounted between a pressure regulating valve 3 and the gear selector valve 4, the inlet and outlet pipes 16, 22 of the control valve being connected through a secondary pipe-line 24 provided with a restriction 25. In the system shown, pressure liquid is supplied by a pump 5 and under normal conditions the pressure in supply line 161 to the clutches or brakes and in a branch line 23 holds the valve element 18 in its extreme left-hand position against the action of a loading spring 32. When a gear change is initiated, pressure in line 16<SP>1</SP> drops and spring 32 moves valve element 18 to the right as shown, so that pressure liquid by-passes restriction 25 and is fed directly from line 16, through valve chamber 21 and pipes 22, 16<SP>1</SP> to operate the selected clutch or brake. On completion of the gear change pressure build-up in lines 16<SP>1</SP>, 22 moves valve element 18 against spring 32 to the closed position. |
