868,668. Fluid-pressure servomotor-control systems. IMPERIAL CHEMICAL INDUSTRIES Ltd. Dec. 21, 1959 [Dec. 31, 1958], No. 42270/58. Class 135. [Also in Group XXVI] A pressure-sensitive valve for use in connection with a single chamber dual thrust rocket motor, that is one designed to operate both as a boost motor and as a sustainer motor (see Group XXVI) is shown in Figs. 3 and 4 and communicates at its forward end with propellent gases by means of a duct 28, see Fig. 1, and at its rearward end with hydraulic fluid contained in the annular space 11, by means of a vent 26. The valve comprises a valve spindle formed in two parts 39, 40 screwed together so as to constitute a differential piston, the spindle also being formed with a collar 42 and with an annular recess 55. A spring-loaded ball is disposed within the spindle part 40 and controls an orifice 47. The spindle is prevented from moving to the right from the position shown, by means of two shear discs 57, 58 as shown in Fig. 4. When the motor is fired, the propellent gases by-pass the sustainer nozzle 17 and flow through the openings 12 in the axially-movable nozzle carrier 8 to discharge through the boost nozzle 19, the parts being in the position shown in Fig. 1. Gases also pass through the duct 28 into the space 34 within the valve 27, the gases then passing through the ball-controlled orifice 47 and into the space 46. The gas pressure on the valve spindle at this stage causes it to burst the shear discs 57, 58 and to move to the right until the collar 42 abuts against the casing. At the end of the boost phase, the gas pressure drops, but due to the high-pressure gas trapped in the space 46, the valve spindle is moved to the left until the annular recess 55 comes into line with the spring-loaded peg 53 which is then projected into the recess so locking the valve stem against further movement. The passage 56 is incovered by the axial movement of the valve stem and so hydraulic fluid in the annular space 11 is vented through ducts 26 and 56, the tabs 22 are sheared by the residual pressure of the propellent gases acting on the nozzle carrier and so the latter is moved to the right to the position shown in Fig. 2. The balls 20 disengage from the holes in the nozzle carrier and so the boost nozzle 19 becomes disengaged. The by-pass passages 12 are now rendered ineffective and propellent gases discharge through the sustainer nozzle 17.
展开▼
