GB824561A - Improvements in or relating to toggle mechanisms - Google Patents

Abstract

824,561. Linkwork. ARON ELECTRICITY METER Ltd. Dec. 28, 1955 [Sept. 27, 1954; Dec. 15, 1954], Nos. 27872/54 and 36370/54. Class 80 (3). [Also in Group XXIX] A toggle arrangement for holding a valve closed but being adapted to be tripped to open said valve comprises a link 58 pivoted at 73 to a fixed point and at 60 to a spring-loaded telescopic link 59, the other end of which is pivoted at 64 to a lever 55 for operating a valve member 28 through a rod 52 and a strap member 35 encircling a valve seat body 7. The lever 55 is loaded in a valve opening direction by a spring 70 which is anchored to a link 71 pivoted at 75 and having an abutment 71a engaging the link 58 to urge the toggle to break. The breaking of the toggle to open the valve 28 is restrained by a tripping mechanism comprising a plate 80 and a toothed wheel 66 rotatable on a shaft 67 and co-operating with a gear segment 65 on an extension of link 58. Anti-clockwise movement of plate 80 to release the toggle is restrained by the tail end of a lever 91 pivoted at 92 engaging a tooth 88 on a V-shaped lever 81 pivoted on the plate 80 and loaded by a spring 84. The lever 91 is adapted to be tripped by a lever 94 operated by an aneroid stack 69 responsive to atmospheric pressure, which then releases lever 81 and plate 80 to break the toggle and open valve 28. The valve 28 may control the supply of oxygen from an inlet 17 to an outlet 6 for the breathing apparatus used by the pilot of an aircraft. The toggle may also be broken manually by operation of the shaft 67 which carries a lever 86 which can engage one limb of the lever 81 to trip it and release plate 80. The lever 86 and shaft 67 also serve for resetting the toggle mechanism and closing the valve 28. Bellows 37 and 45 are secured to the valve operating strap member 35 and are open internally to atmospheric pressure so that there are no unbalanced forces acting on this member.