Self-locking actuators for rotary valve and other two-position rotary elements

摘要

1,064,281. Controlling propulsive jets on aircraft. PLESSEY-U.K. Ltd. Jan. 16, 1964 [Jan. 18, 1963], No. 2284/63. Heading B7G. [Also in Division F1] A shaft 1 for operating an eyelid type deflector in the jet pipe (not shown) of an aircraft jet propulsion engine carries a lever having two arms 2, 3 and two part-circular cam faces 4, 5 formed with recesses 6, 7. The arms are connected to the piston-rods 10 of a pair of rams the cylinders 8 of which are pivoted to a rigid beam 13. A selector valve 15, manually operated by a control rod 33, is bolted, as by flanges 29, 28, to a sequencing valve 14 which moves, through links 64, 18 a pair of rollers 16, 17 carried by swinging arms 62, 63 arranged so that the rollers 16, 17 may engage respectively the recesses 6, 7 to lock the eyelid deflector in either of its two positions. To establish fluid connection between the ends of each ram, fluid is led through the pivot 12 on the beam 13 to a rigid pipe 51 which passes through the piston 9 into a tubular member 52, the end of pipe 51 being sealed by a gland 61. The member 52 is screwed at 54 into an eyelet 55 forming the pivot 11 for arm 2 or 3 and at the other end it is formed with a head 53 which bears against piston 9, the member 52 thereby acting as a bolt to clamp between the piston 9 and the eyelet 55 a tube 57 forming the outer wall of piston-rod 10, which is slidably sealed at 58 within an end plate 59 of cylinder 8. Apertures 56 in member 52 and apertures 60 in member 57 pass fluid from pipe 51 through an annular space between members 52 and 57 into the cylinder 8 behind piston 9. The selector valve 15 has a bore 19 open at 20 to atmosphere and connected at 21 to a pressurefluid supply. Further ports 22 and 23, equally spaced from port 21 connect by passages 24 and 25 to the ends of a bore 27 in the sequence valve 14, separated from bore 19 by a diaphragm 34. A slide valve 30 having carbon seals 31, 32 is housed in bore 19 and is locked in either of two positions by spring-fingers 50 engaging internal grooves in the valve. A combined slide valve and piston element is housed in bore 27, the piston having carbon seals 40, 41 formed with a groove 42 which communicates through restricted bores with axial bores 43 in a piston-rod 36 connected to the catchoperating link 64. Spring-fingers 46 which engage internal grooves 47, 48 in the piston-rod 36 lock piston 35 in either of its two positions in the event of pressure-fluid failure. In operation of selector valve 15, piston valve 14 is actuated to free one of the rollers 16, 17 from its recess whilst bringing the other to bear on its corresponding cam face 4, 5. Pressure fluid is then applied to opposite sides of the pistons 9 to apply a couple to arms 2, 3 to actuate the eyelid deflector, the roller on the cam face then dropping into its recess to lock the deflector in position.