| 摘要 |
<p>912,880. Compressed air actuated jacks. HERION, E. July, 10, 1959 [July 15, 1958], No. 23798/59. Class 8(2). [Also in Group XXIX]. Supply of compressed air to and exhaust from a jack 5 is controlled by a pair of 3-way control valves 50, 60 each having an inlet 2 in open communication with a supply duct 17 and with the inlet 2 of the other valve, a first outlet 3 in open communication with a combined supply and exhaust duct 4 leading to the jack and with the outlet 3 of the other valve, a second outlet 6 open to atmosphere and a valve member 9 which in one position opens a port 7 connecting the inlet 2 to the outlet 3 and closes a port 8 disconnecting the first and second outlets 3, 6 and in its other position closes port 7 and opens port 8 whereby when the valve member 9 of one control valve say control valve 60 as shown is acutated e.g. by manually depressing a knob 16 to open port 7, whilst the port 7 of the other valve 50 remains closed, compressed air passing through the open port 7 into the supply duct 4 is vented through the open port 8 of the valve 50 instead of passing to the jack which therefore cannot move until both valves 50, 60 are actuated. The valve member 9 of each control valve is connected to an operating piston 10 which in its operating position has its side remote from the valve member 9 vented to atmosphere through ports 13<SP>1</SP>, 14 whereon port 8 is closed. In its non-operating position i.e., when control knob 16 is released the port 13<SP>1</SP> is closed by an auxiliary valve 12 and supply pressure transmitted through a throttle valve 19 and a duct 11 depresses the piston 10 to open port 8 and close port 7; the area of port 8 being greater than that of port 7 which may be further reduced by a throttle 18. The auxiliary valve 12 of each control valve may be actuated by a solenoid 15.</p> |
