GB857783A - Improvements in or relating to gas control valves for water heaters - Google Patents

Abstract

857,783. Valves. PEGLERS Ltd. April 5, 1957 [April 5, 1956], No. 10463/56. Class 135. A water heater fitted with gas burners has means for controlling the flow of gas to the burners of the kind in which a gas control valve is opened by manipulatable means associated with thermostat control means adapted to permit closing of the control valve automatically when the water becomes heated beyond a predetermined value. The thermostat comprises a bi-metal strip 41 housed in a chamber 40 within the water storage vessel 10 of the heater. A rod 42 adjustably connected to the bi-metal strip at 50 coacts with a conical member 51 on a spindle 21 such that when the push-button 20 is depressed to move the spindle 21 to the right, the rod 42 overrides the shoulder of the member 51 and retains the spindle 21 in the actuated position against the action of a return spring 23. The movement of the spindle 21 also causes a lever 29 to ride up the inclined surface of a second conical member 25 to rotate a cam to open the gas control valve (not shown). When the water in the heater reaches a predetermined value, the bi-metal element 41 flexes upwards to withdraw the rod from contact with the conical member 51, thereby permitting the spindle 21 and associated conical member 25, 51 to return to their original positions and the gas control valve to close under its spring bias. The temperature at which the rod 42 is released from contact with the conical member is determined by the setting of the rod 42 relative to the bi-metal strip 41. In another embodiment the member 51 is replaced by a stepped conical member adjustably secured to the spindle 21 such that according to the setting of the conical member the rod 42 engages one of the steps to retain the spindle in its actuated position and the gas control valve in the open position until the bi-metal strip flexes upwards to withdraw the rod. In a further embodiment, instead of a spindle 21 actuated by a pushbutton, a rotatable spindle is substituted which carries two cams, one operating the control valve actuating lever and the other contacting the rod 42, as the spindle is rotated against a spring. The cam contacting the rod 42 is notched for selective engagement with the end of the rod 42 until the bi-metal strip 41 withdraws the rod 42.