GB449003A - Improvements in or relating to blowpipe burners for cutting, welding, and similar metal working operations - Google Patents

Abstract

449,003. Blowpipe burners. LINDE AIR PRODUCTS CO., 30, East 42nd Street, New York, U.S.A. Sept. 13, 1934, No. 26323. Convention date, Oct. 28, 1933. [A Specification was laid open to inspection under Sect.91 of the Acts, March 14, 1935.] [Classes 75 (i) and 75 (iii)] The admission of a fuel gas such as acetylene, a combustion-supporting gas such as oxygen and atmospheric air to a blow-pipe burner for cutting, welding, deseaming, and similar metal working operations is controlled directly or indirectly by a single means. In the metalcutting burner shown a block B at the rear of the handle H is fitted with an oxygen valve 29 and an acetylene valve 45 supplying the heating flame, these valves being operated against spring pressure by a single lever L. The neck 68 of the stem of the valve 29 is shorter than that of the valve 45 so that the oxygen is admitted earlier and shut off later than the acetylene. The oxygen supply pipe is connected to a chamber 20 in the block B from which it passes through a control valve V‹ and a tube 25 to a cavity 26 in the burner head He and then returns by a tube 25<a> to the inlet chamber 28 of the valve 29. The acetylene supply pipe is connected to a control valve V<a> which is directly connected to the valve 45. When the valves 29, 45 are opened the oxygen passes to a central passage 38 in a nozzle 33. The oxygen issuing from the nozzle 33 creates a subatmospheric pressure in a surrounding chamber 39, thereby inducing a flow of acetylene through a passage 48 and an exchangeable metering plug 46 from the valve 45 and a flow of air through passages 54 in the nozzle connected to a cap 50 formed with an air inlet 49. The cap 50 comprises two chambers separated by a perforated partition 50<a> covered by a flap-valve 51 preventing back-flow. The mixed oxygen, air, and acetylene are delivered into the throat 55 of an expansion chamber 56 and pass through a tube 57 to a distributing passage 58 in the burner head He. The heating gases are ignited by means of a pilot burner P clamped to the tube 57 and supplied with acetylene from the inlet chamber of the valve 45 through pipes 75, 94 and a regulating- valve 76. When ignition is to be effected a valve 82 is operated against spring pressure to byepass additional gas around the valve 76 and so increase momentarily the pilot flame. The pilot burner nozzle 99 is formed with air openings 102 and is surrounded by a shield 100 formed with air openings 103. The cutting oxygen is supplied to the head H<e> under the control of a valve 107 which is operated by a lever 117 through, a sliding plunger 120. The knob C of the lever 117, the button 90 of the valve 82, and the actuating arm of the lever L are located so as to be operable easily by the thumb and fingers of the operators' hand gripping the blowpipe handle H. In a modification the fuel gas is admitted to the central passage of the nozzle 33 under sufficient pressure to aspirate the air and oxygen into the surrounding chamber 39.