GB1339938A - Welding and cutting devices - Google Patents

Abstract

1339938 Cutting and welding by fusion YAMATO SANGYO CO Ltd 29 Oct 1971 50388/71 Headings B3V and B3R [Also in Division F4] In a welding and cutting apparatus wherein oxygen from a supply 1 and metallic powder 62 from a tank 60 are fed to a central passage (76) (Fig. 2, not shown) of a torch 70, the supply of powder 62 is cut off by a valve 52 if the pressure increases in a reduction valve 20 through which the oxygen is fed. The oxygen is fed from a cylinder 1 to the torch passage (76) via the reduction valve 20, a conduit 13, a powder flow control valve 40 and conduit 13<SP>1</SP> and to an annular passage (74) of the torch 70 via a conduit 4. The oxygen is also fed via a conduit 10 into the tank 60 containing metal powder 62 to cause the powder to be sucked up into a conduit 61 communicating with the conduit 13<SP>1</SP>; and into a chamber 57 of the valve 52 via a conduit 15 to urge a valve plug 53 into a position where a bore in the plug 53 communicates with the conduit 61. If the powder 62 should ignite within the torch 70 causing the pressure in the conduits 13, 13<SP>1</SP> to increase, the pressure is transmitted through a chamber 22 of the valve 20 and a conduit 14 to the valve 52 causing the valve plug 53 to move to cut off the flow of powder 62. A plug 23 in the valve 20 is raised by the increased pressure in the chamber 22 to close the opening of an adjustable valve passage between the chamber 22 and a further chamber 21 connected to the oxygen cylinder 1 via a conduit 19. The oxygen from the cylinder 1 can pass through the valve 20 via a conduit 12 and restriction 34 which reduces the pressure of the oxygen. The torch 70 may be used without powder 62 by lowering the valve plug 23 by means of a screw 28 to cause the chamber 51 of the valve 52 to be pressurized and the valve plug 53 to be moved to the left. The annular passage (74) of the torch 70 is connected to an acetylene supply 6 via a conduit 8.