| 摘要 |
<p>1,078,908. Fluid-pressure servomotor systems. OHIO BRASS CO. May 6, 1966 [May 7 1965], No. 20226/66. Heading G3P. Also in Divisions F1 and F2] The axially movable spool 39 of a closed centre spool valve 10 having an inlet 14 connected to an automatically adjustable variable volume hydraulic pump 12, an outlet 46 connected to a reservoir R and distributing ports 16, 18 connected by flexible lines (28, 30) Fig. 2 (not shown) to opposite ends of a double acting hydraulic piston and cylinder motor (20) is variably displaced to an operative flow control position against biasing springs 60, 60a by fluid-pressure admitted from the inlet 14 past one or other of poppet valves 68, 68a to an associated chamber 64, 64a surrounding stepped ends 56 of the spool 39; the relevant poppet valve being unseated by a variable fluid-pressure signal generated by a manually operated remote means 34 connected to said valves by lines 35, 35a. The signal generator 34 forms a pair of master cylinders of a telemotor system having the poppet valves as the slave units. To extend the motor piston the actuating lever 98a of the signal generator 34 is swung clockwise to depress a plunger 86a against a spring 100 and into a chamber 92a to isolate the latter from a surrounding vented chamber 85a. The resulting pressure pulse transmitted through line 35a unseats poppet 69 and allows inlet pressure fluid to flow via a passage 37a and an orifice 80a to chamber 64a to move spool 39 to the left and thereof connect inlet passage 37 to port 16 and to connect port 18 to reservoir R. An axial bore 104 in the spool has a central lateral port 110 open to reservoir and restricted lateral end ports 108, 108' open to chambers 64, 64a for bleeding of same. When pressure in chamber 64a suffices to displace the spool the desired amount the resulting back pressure unseats poppet 69 and the fluid trapped in line (35a) which may be of deformable plastic material reacts against the lever 98a and provides proportional "feel" to the operator. A modified signal generator (34') Fig.7 (not shown) for providing "feel" when using relatively rigid material for lines (35, 35a) comprises a hollow spring-biased plunger (185) containing at its lower end a solid spring-biased piston (190) which when the lower end of the plunger (185) rotates chamber (92') from chamber (85a) the pressure generated in space (92') reacts against piston (190) and its biasing spring (194). Each slave unit may comprise a piston (124) Fig. 4 (not shown) having a peripheral groove (126) which when in register with a port (122) allows inlet pressure fluid to pass through a transverse passage (128) and an axial passage (128a) to a port (120) leading to the associated space (64, 64a). In a further modification a floating slave piston (152) Fig. 6 (not shown) bears on a spoollike plunger (158) having peripheral recesses (164, 168) and transverse and axial passages (170, 170a) whereof the fluid inlet pressure may be transmitted through an outlet port (174) to an associated space (64, 64a).</p> |
