GB772728A - Improvements in and relating to the control of gas valves - Google Patents

Abstract

772,728. Clockwork actuated valves. UNITED GAS INDUSTRIES, Ltd. Dec. 29, 1954 [Dec. 29, 1953], No. 36071/53. Class 135. A gas valve time-controlled mechanism comprises a valve operating element 26 angularly adjustable from an initial to a second position in which it is a positively detained to open or close the valve 10 in a casing passage 4 and a rotary timing element 35 adjustable from zero through an angle proportional to the time interval required, a common biasing force tending to return both elements to their initial positions, and a clockwork timing mechanism set into operation by the timing element and which frees the valve operating element when it returns to its initial position after a predetermined time to thereby close or open the valve. The mechanism has a rotary knob moving over a dial on the rear face, as seen in Fig. 2, of the body 1, and its spindle 17 at the opposite face carries an arm 35. A valve operating lever 26 having one end at 27 operable at the dial face is connected to a box 20 rotatable on the spindle and housing a helical spring connected at one end of the spindle and at the other end to the box. The lever 26 has lugs 25 engaging a lever 14 connected to the hinged valve 10. On moving the end of the lever 26 down in the slot 27 a box tooth 34 engages a pawl 32 which thus holds the valve open. The knob, spindle 17 and arm 35 are then rotated anti-clockwise to wind the spring through an amount corresponding to the time required before the valve is actuated. The spindle then rotates in the opposite direction under the control of an escapement mechanism having a friction clutch engagement with the spindle 17. When the arm 35 returns to its initial position it engages a cam 37 which moves the pawl 32 so that the spring moves the lever 26 upwards and closes the valve. The cam 37 may be fixed or have limited movement on the pawl 32 as shown to allow element 26 to open the valve before or after setting the timing mechanism. In order that the mechanism may allow gas flow after a predetermined interval and stop it after a further interval, two of the mechanisms may control the gas in succession, the mechanism being separate or combined with one dial. A sound or like warning may be utilized with the mechanism.