Patent GB-1279963-A (GB)
Title: Improvements relating to valve assemblies for gas burning appliances
Inventor: HOLLINS HUMPHREY BOLTON
IPC: F23N1/00
Filed: 1968-06-27
Abstract: 1279963 Gas supply valves for burners RICHARD BAXENDALE & SONS Ltd 26 Sept 1969 [27 June 1968] 30777/68 Heading F2V [Also in Division F4] In a gas valve assembly for a gas burning appliance incorporating space heating means in addition to a gas fired boiler for supplying hot water and/or for central heating, superposed plates comprising a valve body 20, a cover 21 and a cap 22 are secured in a gas-tight manner. Within the superposed plates are formed gas flow passages between a gas inlet 24 and first and second gas outlets 30 and 76 leading to gas burners of a radiant space heater and a gasfired boiler respectively, A gas flow governor 32 is disposed in the passages between inlet 24 and outlet 30 and a solenoid operated valve 64 and a main gas flow governor 48-51, influenced by the pressures prevailing in the flow passages are disposed between inlet 24 and outlet 76 to control the gas pressure at the second gas outlet. Gas passes from inlet 24 through opening 26 and port 28 into an upper chamber 29 and out of gas outlet 30 to a manual gas cock (not shown) controlling gas supplied to a burner of the space heater, being governed by a gas governor 32. Supply of gas to the gas fired boiler is initiated by operation of a solenoid 62 (Fig. 8) which draws upwards, against the action of a spring 67, a spindle 63 and an attached valve member 64. A diaphragm 61, urged against valve member 64 and a valve seat 66 by the action of springs 65 and 67, when the solenoid is not activated, is thus caused to lift off valve seat 66 maintaining contact with valve member 64 until a face 68 of the valve diaphragm 61 abuts a face 69, after which valve member 64 continues to rise, enabling gas in the lower chamber 27 to pass via passages 43 and 44, chambers 45 and 53, controlled by a gas governor 52 and via passage 58 into a chamber 59, from where it reaches an outlet chamber (71) (Fig. 3, not shown) after passing round the sides of the valve member 64, over the valve seat 66 and through the holes 72. This flow of gas from chamber 45 causes pressure therein to drop and which causes a slow fall in pressure in a chamber 46 which is connected to chamber 45 by a narrow passage 47, thus causing a diaphragm valve 51 to rise slowly, so lifting a restrictor valve 50 from a valve seat 49 within a chamber 41. This allows gas to flow from the lower chamber 27 via an opening 40 into the chamber 41, through passage 48 into an elongate chamber (75), Fig. 3 (not shown), to the chamber 70, then over the valve seat 66 to the holes 72 and via outlet chamber (71) to the outlet 76. Provision may be made to close passage 58 and take gas from the chamber 53, pass it through a thermostat (not shown) and introduce it into chamber 59, enabling the gas valve assembly to modulate the main gas flow automatically. In another embodiment, Fig. 10, a gas governor valve 106 differs from the one already described in having a valve seat 110 which closes against the gas governor valve face in the event of a failure of the gas supply. Because of the small area of the valve seat on which the gas pressure can act, re-establishment of the gas supply would not re-open the valve, so a very small hole 111 is provided so that, provided the manually operated stop cock in the pipe (not shown) from outlet 108 is turned off, gas pressure will slowly build up in chamber 107 and act on diaphragm 109 to open the gas governor valve. The diaphragm valve 51 incorporating the restrictor valve member 50 is replaced by a diaphragm 118 having attached a tube 136 which acts as a restrictor to the gas flow until it lifts clear of a valve seat 119. In an automatic control system (Fig. 12) gas valve assembly V and solenoid S are connected via a sensing unit SU and a cut-out device C to an external control (not shown) for example, a room thermostat or a clock. The sensing unit SU and solenoid S are also in circuit with a spark unit SP connected to a spark electrode SE next to the boiler burner rail B. A flame sensing electrode HS is also in circuit with the sensing unit SU. When the external control calls for heat, solenoid S is energized briefly to allow gas to flow to burner B. Simultaneously, spark unit SP produces sparks at electrode SE to effect ignition. The flame sensing electrode HS detects whether ignition has taken place and, if so, the sensing unit SU de-energizes only spark unit SP, otherwise the sensing unit SU de-energizes both spark unit SP and solenoid S and opens the cut out device C to close down the system. Another embodiment (Fig. 13, not shown) includes a pilot light to give ignition to the burner rail.