Patent GB-397328-A (GB)
Abstract: 397,328. Thermally-actuated valves. BOSCH AKT.-GES., R., 4, Militõrstrasse, Stuttgart, Germany. Oct. 26, 1932, No. 29933. Convention date, Nov. 5, 1931. [Class 135.] In a controlling arrangement for gas-burners the main gas-valve A is controlled by a heat-sensitive element (such as the diaphragm 15), which is heated by the flame of a control burner B, the effective position of the flame relative to the heat-sensitive element being varied according to the working conditions to be controlled. In the form shown in Fig. 3, the length of the flame from the control burner is variable according to the flow of water in a pipe 40 and the temperature of water in a heater 30. The water-control valve E comprises a plate 41 held in the water current on an arm 37 pivoted to a water-tight diaphragm 39 and carrying a valve member 35. The thermal valve C comprises an expansible tube 29 surrounding an inexpansible rod 28 carrying a valve disc 27. A hand-cock D in the control pipe, an ignition device F, and a throttle G for neutralizing changes in gasvelocity are also provided. In operation, the ignition-valve 49 is depressed and gas flowing from the main gas pipe 10 through pipe 46 into the casing 17 of the control burner is ignited at the opening 19. The diaphragm 18 of the control burner expands and lifts valve 20, allowing gas from the pilot pipe 44 to maintain a small flame when the ignition valve is released. The hand-cock D is then turned to the open position shown, gas from the control pipe 22 causing the control flame to extend to heat the diaphragm 15 and open the main valve. The control flame is deflected by a metal lug 57 attached to the diaphragm so as to ignite the main burner 14. The throttle G comprises a springy strip 53, which, on an increase in gasvelocity, throttles the entrance 54 to the control pipe 22. A byepass 55 controlled by a cock 56 is provided. In the form of throttle shown in Fig. 8 the springy strip 53 is mounted on a hollow rivet 60 in a removable insert 61. The hollow rivet serves as the byepass. In the modified control burner shown in Fig. 10, ignition gas passes to the casing 17 of the control burner from the pipe 46 and between the pipes 78, 79, while pilot gas is supplied from the control pipe 22 and through the narrower bore of the switch H and the pipe 78. The pipes 78, 79, which carry the control burner, are mounted on a plug cock 80, which cuts off the ignition gas when the burner is rotated so as to face the diaphragm 15. On turning the switch H so as to present its larger bore to the control pipe 22, the control flame is lengthened and the main valve A operated. In the modified controlling arrangement shown in Fig. 14, the control burner is pivoted on a pipe 65, the joint serving as a control cock. When water passes through the pipe 70, the difference of pressure across the throttle 71 is applied to a diaphragm 67, which, through links 75, 66 swings the control burner so that the flame passes through the aperture of the funnel 62 and strikes the diaphragm 15, the cock 65 being simultaneously opened to lengthen the flame. The diaphragm 15, Fig. 6, may be provided with cooling ribs 77 which touch it at its centre but are elsewhere separated from it.