GB1050435A - - Google Patents

Abstract

1,050,435. Valves. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Sept. 19, 1963 [Sept. 28, 1962], No. 36904/62. Heading F2V. A vacuum stop valve comprises a valve closure member 6 fixed to a boss 11 which passes through an aperture in a member 9 pivoted on a shaft 6<SP>1</SP>, pegs being provided to prevent rotation of the closure 6 relative to the member 9. A plate 12 rotatable on the boss 11 and located above the member 9 has peripheral slots which carry wedges 16 which are retained radially by springs 17, secured to the plate 12 by screws 18, and having inner ends which bear on a flange of boss 11. When the closure 6 is positioned above a valve seat, rotation of the plate 12 causes the wedges to engage the valve housing and then press the closure on to its seat by engagement of the wedges with surfaces on the closure 6. A member 23, pivoted to the member 9 at 24, has a lug 25 which engages recesses at the ends of a sector 29, fixed to the housing, when the valve closure is at an open or closed position. A member 8 fixed to the shaft 6<SP>1</SP> engages pin 26 to release the lug and rotate the member 9 to open the valve and a face 27 engages and releases the lug to rotate the member 9 to close the valve. When the lug engages the recess in the closed position, further rotation of the member 8 rotates the plate 12 to provide the wedging action as described above, through a toggle mechanism 22 which will pass through its dead centre position before the member 8 engages a stop 35.