Patent GB-694992-A (GB)
Title: Improvements in or relating to oxy-acetylene blowpipes
IPC: F23D14/40
Filed: 1951-05-18
Abstract: 694,992. Blowpipe burners. KAZANDJIAN, B., and KAZANDJIAN, V.. May 18, 1951 [May 20, 1950], No. 11711/51. Class 75(i) In an oxy-acetylene blowpipe comprising means for stopping the acetylene flow, means for causing a small flow of, acetylene to act as a pilot flame when the means for stopping the acetylene flow is closed, means for stopping the oxygen flow and separate means for regulating the oxygen flow, all the above means except the means for causing a small pilot flow of acetylene are operated by the same knob. Acetylene is supplied by a pipe 6 to a chamber 33 in a member 8 which fits friction tight within a cylindrical sleeve 1a forming the body and handle of the blowpipe. An acetylene outlet passage 35 from the chamber 33 is closed by a spring-urged valve member 36 pushed, to open position by a rod 48 which is slidably mounted in the member 8 and has a reduced end extending through the acetylene outlet passage 35 to abut the end of the valve member 36. The valve membr 36 is hollow and a small pilot flow of acetylene passes to its interior through a hole in its side wall and then passes into the acetylene outlet passage 35 through a hole 42 in the end of the valve member and through axial and radial holes in the abutting end of the push rod 48. The end hole 42 is controlled by a needle 45 screwed into the hollow valve member 36. The acetylene passes from the outlet passage 35 through a pipe 9 to a passage 55 in a head member 2 fitted in the end of the sleeve 1a and thence to a jet 3 detachably mounted on the end of the head. Oxygen is supplied by a pipe 7 to a chamber 19 in the head 2 and passes therefrom through a hole 20 in a transverse wall in the head to a nozzle 12 discharging into the jet 3. The outlet aperture of the nozzle is controlled by the end of a needle 14 and the edge of the hole 20 in the transverse wall is formed as a seat for a cut-off valve member 24 formed on the actuating rod 15 of the needle. The actuating rod 15 is , threaded into the head and has a radial pin 26 projecting through a slot in the sleeve 1a and terminating outside the sleeve in a control knob 29; the slot is masked by a ring 28 which turns with the radial pin. Rotation of the actuating rod 15 by a fraction of a turn displaces the rod and the needle axially to open the cut-off valve 24 and to regulate the flow through the outlet aperture in the nozzle. The actuating rod 15 and the push rod 48 are in end to end arrangement. so that the actuating rod pushes the push rod to open the acetylene valve. A small gap between the ends of the two rods is adjusted by a cap 53 screwed on to the end of the push rod. The needle 14 is either integral with the rod 15 or is mounted to slide in the rod against the action of a spring therein. In the latter case the needle is designed so that it completely cyloses the nozzle outlet aperture and the travel of the needle into the rod is greater than the gap between the ends of the two rods so that the acetylene valve opens whilst the needle is still closing the outlet for the oxygen. The gas supply pipes 6, 7, 9, the 'head 2 and the member 8 form a rigid structure removable from the sleeve 1a. The end of the sleeve is closed by a wall 4 held by screws. In a modified construction the passage 55 conveying the acetylene through the head 2 to the jet is closed to a greater or less extent, by the coneshaped end of a screw screwed from the outside into the head 2 and provided with a lock-nut. The actuating rod 15 is threaded into a member which itself is threaded into the head 2 and presses a stuffing round the actuating rod. The ring 28 masking the slot in the sleeve is replaced by a collar loosely encircling the sleeve and having a helical slit forming a passage and a stop for the radial pin 26. The collar is fixed in adjusted position by screws. The needle 45 for controlling . the flow of acetylene to the pilot flame extends rearwardly through the end wall 4.