Patent GB-544964-A (GB)
Title: Improvements in blowpipe apparatus
IPC: F23D14/46
Filed: 1941-02-21
Abstract: 544,964. Blowpipe burners. LINDE AIR PRODUCTS CO. Feb. 21, 1941, No. 2377. Convention date, May 4, 1940. [Class 75 (i)] [Also in Group XXII] A manually operated portable blowpipe apparatus for de-seaming, cutting, flame-machining or a like operation on a metal body is provided with means for feeding a ferrous metal wire or rod to the heating flames at the start of the operation and with an air jet for removing slag &c. controlled by the lever operating the cutting oxygen valve. In the apparatus shown oxygen, acetylene, and compressed air are supplied to the rear end of the blowpipe through connections 12, 15, 32 respectively. The preheating oxygen and acetylene controlled by valves 17, 18 pass through concentric tubes 16, 14 to a head C fitted with a nozzle N, and the cutting oxygen passes to the nozzle N through a valve 19 operated against spring resistance by a lever L and a tube 13. The lever L is formed with a large recess 25 engaging a collar 22 at the outer end of the valve stem 21, so that during the initial movement of the lever the valve 19 remains closed. During this initial movement an arm 44 on the lever L operates through a rod or cable 76 a mechanism F feeding a rod or wire W into the pre-heating flame. Further movement of the lever L opens the valve 19 and at the end of the opening movement the arm 44 operates a bent lever 41 to open a valve 35 to allow compressed air to pass through a tube 33 to a curved or bent swivelling nozzle 95 secured to a head 91 attached to the head C. The valve 35 may be operated independently of the valve 19 by the lever 41. The nozzle N is provided with a work-contacting collar 103 and the head is provided with a shield 104 which may be so formed as to contact with the work when the nozzle is at the correct angle thereto. The feeding mechanism F is mounted in a housing 40 clamped to the tubes 13, 16 and comprises a lever 59 mounted on a cross bolt 61 in the housing 40 and formed with a pair of rockers 65 held in contact with a boss 63 on the housing by a spring 67 on the bolt 61. The lower end of the lever 59 engages a stem 69 on a clutch 51 slidable in guides at the base of the housing. The rod W passes through guide bushings 48, 49 at the base of the housing and through an aperture 56 in the clutch 51. 'The operation of the rod 76 by the lever L rocks_ the lever 59 and causes the clutch 51 to tilt and to grip the rod W at the sharp front edge of the aperture 56 and thereby feeds the rod W forwardly. When the clutch reaches the limit of its forward movement the fulcrum of the lever 59 shifts from the rockers 65 to the lower end engaging the stem 69, and the oxygen valve 19 and air valve are then opened successively by the movement of the lever L. When the lever L is released the clutch 51 is moved rearwardly by a spring 58 and, owing to the chamfered rear edge of the aperture 56, it rides freely over the rod W which is held frictionally by spring- pressed balls 82, 83 in the guide bushing 49. The feed of the rod W may be varied by adjusting the guide bushing 48 by its knurled head 86. The blowpipe apparatus may be constructed with the lever L arranged above or below the handle and for right or left handed operation. Specifications 488,612 and 514,574, [both in Group XXII], are referred to.