GB673372A - Improvements in or relating to hydraulic servo motors and the like - Google Patents

Abstract

673,372. Locking rods. HOBSON, Ltd., H. M., and MOTT, L. F. May 12, 1950 [June 2, 1949], No. 14841/49. Class 80 (iii). [Also in Group XXIX] In a duplicated hydraulic control system for operating aircraft control surfaces and the like in which seizure of either of the servo-control valves 25, 25a causes a collapsable member to collapse and so disable the affected servomotor, interlocking means are provided between the two collapsable members so that on either of them collapsing the other is locked against collapse. As shown in Fig. 1, an input member 86 operated by the pilot actuates the valves 25, 25a through linkages 287, 287a also connected to rods or extensions 112, 112a of the collapsable members. The latter may be constructed as described in Specification 673,369. Between the rods 112, 112a are two parallel locking bolts 111, 111a, each with a rounded end 4 or 4a engaging a correspondingly shaped groove 6, or 6a and a flat end 7 or 7a adapted to engage a square groove 8a or 8. The bolts are normally maintained in the rounded grooves by springs 5, 5a but on displacement of one of the rods, say 112, the corresponding bolt 111 is depressed so that the end 7 engages the groove 8a and prevents the rod 112a from moving and therefore the corresponding collapsable member from collapsing. The bolt 111 is locked in its displaced position by a spring-loaded latch 9 engaging a groove 11. Where the rods 112, 112a are further apart as in Fig. 2, the locking bolts are in two parts 211, 311 and 211a, 311a, the parts 211, 211a with rounded ends being pressed into the grooves 6, 6a by springs 5, 5a which also tend to keep pairs of contacts 13 and 13a separated. The parts 311, 311a with flat ends are prevented from engaging grooves 8, 8a by springs 15, 15a respectively and abut cores 60, 60a of solenoids 61, 61a. On movement of one of the rods, say 112, the part 211 is depressed and the contacts 13 are made so that current from the leads 18 passes to the solenoid 61. The core 60 is depressed against a spring 115 and the spring 15 and the part 311 engages the square groove 8a. The bolt part 211 is locked in its depressed position by a spring- loaded latch 16 and the part 311 is similarly locked by a latch 21 which causes spring contacts 20 to spring apart and open the circuit again. The core 60 then returns to its normal position and causes the contacts 19 to be separated. One of the contacts 19 is carried by the core 60 and the other is carried on a rod 12 of insulating material secured to the part 311 and passing through the core 60. Specifications 627,737 and 673,371, [both in Group XXIX], also are referred to. The Provisional Specification refers also to Specifications 673,370 and 673,374, [both in Group XXIX]. Reference has been directed by the Comptroller to Specification 617,375, [Group XXVIII].