Patent GB-130751-A (GB)
Title: Improvements in the Method of and in Apparatus for Holding in Position Preparatorily to their being Welded Together the Plates and Frames of Ships and the like Structures.
IPC: B63B3/14
Filed: 1918-08-06
Abstract: 130,751. Cammell, Laird, & Co., Carter, Sir G. J., and Wavish, S J. Aug. 6, 1918. Welding; uniting by fusion. - In uniting the plates and frames of ships and other structures by welding processes such as the " quasi-arc," the plates and frames are secured together, preparatory to the welding, by means of electro-magnets which are preferably energized from the welding- circuits. Clamps may be combined with the magnets, and the pole-pieces of the magnets may be arranged at an angle to each other, so as to be capable of clamping plates at any required angle, and may also be arranged so as to form a butt joint, or be curved or capable of adjustment to be at different levels in order to form overlap joints. The windings of the magnets may be protected by water-tight or by perforated zinc covers. In its simplest form, the electro-magnets are formed of U-shaped bars 1, Figs. 1 and 7, of rectangular section, the pole-pieces 2 of which terminate in faces 3 in the same plane, and, as shown in Fig. 7, these are used to hold plates 14, 15 and a strengthening-plate 16 together while the gap 17 is filled with welding-metal by the quasi-arc method. The bar 16 may be previously connected to one of the plates 14, 15 in the same manner that the device is shown in Fig. 1 as being used to form an overlap joint between plates 23, 22. The plates 22, 23 are secured together by means of a screw clamp 21 attached to one pole-piece 2, and the overlapping edges are connected by spot-welding while, so held. The coil 6 of the magnet is wound on an insulating-sleeve 5 and between insulating-washers 7 arranged adjacent to metal cheeks 4 welded to the polepieces 2. A switch 8, plug socket 9 for leads, and a brass handle 12 are all mounted above a bar 11 of non-magnetic material, and a watertight or perforated zinc or like casing 13 surrounds the coil 6. For holding inclined plates as at 28, 29, Fig. 5, the magnet core 1 is fitted at each end with two pole-pieces 2<c>, 2d, the faces of which are respectively fixed in an horizontal plane and are in planes the inclination of which can be varied as required by turning the arms 2<d> about the core 1 and holding them by screws in the adjusted position. A brass or other non-magnetic sleeve may separate the pole-pieces slightly from the core so as to distribute the magnetic flux equally between the pole-pieces. In a further modification for holding plates at right-angles to one another, the magnet is formed at each end with pole-pieces in the form of a rectangle 2<b>, Fig. 10, divided by a gap 24, and formed with faces 3<a>, 3<b> for holding two plates as 26, 27 at right-angles. The rectangular part 2b is fitted to a circular part attached to the magnetic core, and this form may be used for holding plates at other angles. In a further modification, a magnet fitted with a clamp as shown at the left in Fig. 1 may be formed with the opposite pole-piece arranged. to be adjustable in a vertical direction, so that the device can be used in connexion with plates which are not in the same plane. The clamping- device may also be in the form of an electro. magnet.