GB251091A - Improvements in or relating to blowpipe apparatus - Google Patents

Abstract

251,091. Carbic, Ltd., and King, O. C. F. April 7, 1925. Blowpipe burners. - An oxyacetylene or other blowpipe burner is provided in the base or stock with a mixing or expansion chamber C which is connected by a number of tubes D to a burnerhead F formed with a straight or curved narrow slot or flame orifice G. In the form shown in Figs. 2 and 4, the tubes D enter a number of holes c<2> arranged in a semi-circle in a diaphragm C<1> at the front of the chamber C. A plate H formed with a semicircular or segmental wing may be rotated in front of the holes c<2> so as to cut off some of the tubes D to vary the width of the flame. The stock A is clamped to the diaphragm C by means of a clamping ring M and contains an injector nozzle B supplying oxygen under pressure and acetylene. The burner-head F is attached to a stop d<1> in which the tubes D terminate, and, in order to reduce the conduction of heat to the tubes, the head is formed with a narrow neck j<2> and with heat-radiating fins f'. The fins may also serve to guide or support the burner-head relatively to the work. The gaseous mixture passes from the tubes D through channels f<4> to a tubular expansion and mixing chamber E formed immediately behind and parallel to the flame orifices. In order to prevent the flame from spreading along the orifice G when some of the tubes only are supported with gas, a checking device may be fitted in the mixing chamber E. This checking device may comprise a ribbed rod, each annular channel between the ribs corresponding to one passage f<4>. A ventilating cover J may be provided around the tubes. This cover is preferably made in two sections which when clamped in position by a nut K place the tubes D in tension so as to maintain the tool rigid. In the form shown in Figs. 5 and 7, the stock is formed with an elongated tapered mixing chamber C from which lead tubes D to the burner-head F. The burner-head F is secured to the base by a tension rod P. The tubes D are of smaller diameter at their inlet ends so as to throttle the gas momentarily. The burnerhead is provided with wedge-shaped partitions N formed with apertures n' and having knife edges approaching closely the lips of the orifice G. Guide rollers may be provided on the burnerhead so as to support the tool during its movement on the work. The Provisional Specification states that a twisted sheet-metal strip may be inserted in each tubular passage to give a spiral movement to the gases.