GB546009A - Improvements in or relating to portable apparatus for flamecutting metal - Google Patents

Abstract

546,009. Annealing. SWIFT LEVICK &SONS, Ltd., and HORSBURGH, G. D. L. May 5, 1941, No. 5799. [Class 72] [Also in Groups XXII and XXXV] A portable flame cutting apparatus comprising a frame in relation to which the burner is traversed along the desired path, has secured to the frame a permanent magnet of high coercivity provided with polar faces shaped to obtain a bearing on the work and so disposed as to support the apparatus in operative position when bearing on the work. The apparatus comprises a frame 20 having bifurcated uprights 21 with collars 24 to guide and support a slotted reciprocating slide 23 in which is mounted a mandrel 36 carrying the burner 38. The mandrel is secured in a clamp 35 rotatably mounted on a crank pin 34 adjustable in a slotted crank 33 which is rotated by worm gear from a pair of handwheels 32. To the frame may be secured by bolts a permanent magnet which for cutting cylinders of different diameters is formed with inclined polar faces 43 which may be smooth or ribbed, and with flat faces in alignment for flat faced work. For cylindrical work of a particular size the magnet may have two limbs 46 and a central stem 47 with curved surfaces 48. In another form the frame may have two angular flanges 49 to each of which a separate permanent magnet 40 may be fixed, the faces of which are inclined to each other. The magnet may be provided with slipped ends for receiving detachable pole shoes 50 with polar faces of various shapes. The magnets may be made from nickel aluminium-iron alloy containing cobalt and copper and heat treated to develop the magnetic characteristics as described in Specifications 431,660 and 439,543. The magnetic characteristics may be enhanced in the direction of the flux through the polar faces by subjecting the cast magnet metal to the influence of a magnetic field in that direction whilst cooling from a temperature above to one below the Curie point.