| 摘要 |
<p>1,156,571. Fluid-pressure servomotor systems. ITT INDUSTRIES Inc. Jan.6, 1967 [Jan. 12, 1966], No.839/67. Heading G3P. In a servosystem comprising a single acting servomotor supplied from a pressure source and controlled by a bleed valve, the latter is inoperative until the servomotor has been actuated by a predetermined minimum extent by the pressure source. As shown, a fuel valve 42 is controlled by a singleacting piston 36 supplied by pump 10 via line 24. The piston chamber 32 is connected via lines 90, 25a, relay valve 98, 99 and line 60 with servobleed valve 64. The latter is carried by a pivoted armature 66 controlled by solenoids 69, 70 connected in a bridge circuit with potentiometer type resistances 74, 75 of which the former has a wiper controlled manually or automatically at 78 whilst the latter has a feedback wiper connected to valve stem 40, an A.C. source 76 supplies the bridge circuit. In the closed position of valve 42, a piston 87 resting on piston 36 closes line 90. Upon starting pump 10, the piston 36 is moved to allow piston 87 to open line 90, such initial movement ensuring that adequate fuel flows to sustain combustion. Once line 90 is open, valve 64 controls piston 36 via relay valve 98, 99. When valve 64 signals rapid closing movement of valve 42, a closure member 104 allows additional bleed through line 25b. Valve 98, 99 is slightly open when member 104 is seated. A vane 30 vents line 24 when the motor driving pump 10 is stopped. In the modification of Fig. 2 (not shown), valve 104 is omitted and valve 98, 99 is replaced by a hinged bell crank valve member (53, 54).</p> |
