Patent GB-374631-A (GB)
Title: Improvements in or relating to apparatus comprising co-acting magnetic tracers and templates, for use more especially in the cutting or welding of metals
IPC: B23K7/00
Filed: 1931-06-10
Abstract: 374,631. Pantographic apparatus. AIR REDUCTION CO., Inc., 60, East 42nd Street, New York, U.S.A. June 10, 1931, No. 16895. Convention date, July 10, 1930. [Class 97 (iii).] In a machine having a universally movable frame carrying a cutting or welding torch or other member and a magnetic tracer for follow. ing a templet, two co-axial rollers rotated in opposite directions are provided on the tracer for co-operation with different portions of the templet respectively. One member 5 of the universal frame has a bracket 6 secured thereto by a screw 7, guides 8, 9 on the bracket being adapted to receive a slidable member 10 on which the tracer is vertically adjustable. Rollers 11 on the member 10 engage the upper guide 8 and the tracer may be secured in any adjusted position by a screw 12 and pinching block 13, Fig. 4. A pinion 18 secured to a shaft 19 rotatable in the member 10 engages a rack 17 on the tracer for vertical adjustment thereof along guides 15, the rack teeth having clearance on the pinion so that the tracer, which rests on the templet, may have a vertical floating movement. A hand-lever 20, Fig. 5, is secured to the shaft 19 for adjustment of the tracer and carries a pawl 21, controlled by a spring button 22, for engagement with a fixed quadrant 23 to retain the tracer in the adjusted position. The casing 16 of the tracer carries an electric motor 24 having an adjustable speed governor 25 and has secured thereto a magnet frame 26 for the rollers, the frame comprising annular portions 27, 29 and a head 28 of magnetic material and a cap 31 of non-magnetic material. The core of the magnet consists of two co-axial shafts 32, 33, the lower end of the former constituting one roller 34 whilst the latter has the other roller 35 secured thereto. Worm wheels 36, 37 on the shafts 32, 33 are driven in opposite directions from the motor 24 through worm and spur gearing 38, 45 and further worm gearing 46. The tracer is guided by a main external templet 56, Fig. 2, of magnetic material for co-operation with the roller 34, but for executing sharp corners &c. an external templet 57, also of magnetic material, is provided for co-operation with the roller 35. A gap or a portion 60 of non-magnetic material is provided on the templet 36 so that this templet and its roller cease to function when the other templet and roller commence. The templets are cut away at 80, 81 to provide clearance for the roller not in use but to allow its magnetic influence to assist the working roller. The weight of the tracer, but not of the universal frame, is carried by the upper surfaces 61, 62 cf the templets, an antifriction roller 64, Fig. 4, of non-magnetic material being rotatably carried by the shaft 32 and having a portion 65 to engage the templets. Dust-excluding rings 70, 71 are provided. This arrangement is stated to cause the weight of the tracer to make the roller adhere more securely to the templet, but in a modification the tracer is supported by a ball or roller in the end of the shaft 33 directly engaging the underlying surface of the templet. Specifications 139,454, 146,390, and 173,935, [all in Class 83 (iv), Metals, Working], are referred to.