Patent GB-560141-A (GB)
Title: Welding apparatus
IPC: B23K11/06
Filed: 1942-06-02
Abstract: 560,141. Electric welding; transformers. STEVENS, A. H. (Yoder Co.). June 2, 1942, No. 7488. [Class 38 (ii)] [Also in Group XXII] Electric welding apparatus comprises a transformer arranged between spaced bearings, the secondary winding being connected to, and rotated by, disc-like electrode's through the intermediary of a pair of conductor devices mounted in one of 'the bearings. In one form, the whole transformer is rotated by the electrodes, the current,supply to the primary winding being controlled by a variably - tapped auto - transformer. A frame 9- is raised and lowered by tubular nuts 14 and shafts 10 which are 'rotated by chain-and-sprocket gear 15, 16 from a motor 19a. Depending 'from the frame 9 are standards 20, 20a carrying bearings 21 for a transformer mounting which comprises cage-like sections 22a to which the core 3<SP>1</SP> is secured, and outer and inner concentric insulated conductors 22b, 22c directly connecting the secondary windings 3b to rotating electrodes 4, 4a which engage a pipe A between rotatable rollers 6. The primary windings 3a are connected by leads 34, 34a, terminals 35, 35a, and insulated collector rings 37, 37a on shaft 24. The rings 37, 37a are engaged by one or more spring-pressed brushes 41 carried by annuli 42 which are separated by insulating discs 46 and to which are connected terminal members extending through bosses on adjacent standards 20 and connected to supply leads from an autotransformer 93. Cooling medium under pressure supplied at 52<SP>1</SP> passes through a pipe 51 within an axial duct 51x in the shaft 24, and thence by a flexible pipe, branch conduits 22x<SP>11</SP>, a conduit 22x in the conductor 22c, and an end passage 22x<SP>1</SP>, a return conduit 22x and branch conduit 22x<SP>11</SP>, to a second flexible discharge pipe connected to the duct 51x outside the pipe 51, and finally to a discharge pipe 54. Rotation of the transformer mounting for grinding the electrodes 4, 4a may be effected by a' .gear train 2a, 2g connected to a motor 2h<SP>1</SP> under the control of a clutch 2f<SP>1</SP>. Fig. 10 shows'substantially semicircular conductors 55, 55a provided with cooling ducts 55x, 55x<SP>1</SP> and arranged side by side on the bearing 21 adjacent the electrodes. This latter bearing may be disposed outside the electrodes. In a modification, the bearing remote from the electrodes is in the form of a cradle giving ready access to the connections to the primary windings 3a, Fig. 7a. In a second form, only the secondary of the transformer is rotated by the electrodes, the primary windings being provided with tappings for voltage regulation. The frame carrying the transformer is raised and lowered by threaded rods 155 and a motor 151 on a cross member 111 carried by standards 109, 110, whilst the electrodes may be rotated for grinding purposes bv means of a motor 157 with a chain-andsprocket drive 160, 160a, 161. Cooling medium is supplied at 136a and passes through a pipe 136 and opening 123x to a discharge pipe 137a. The primary member comprises a number of laminated steel cores 117 with copper tape windings 118 uniformly spaced inside an hexagonal shell 121 secured to bowed frame members 114. The secondary winding 131 comprises ring-like members with inwardly extending lugs 131a, 131b engaging the outer and inner conductors 123, 124 leading to the electrodes 102, 103, the conductor 124 being cut away to accommodate a laminated steel core 129. In a modification, the fixed primary is carried by a frame raised and lowered by means similar to that shown in Fig. 1 and carrying one bearing outside the electrodes. Cooling of concentric conductors is effected as before, but no means are provided for independent rotation of the electrodes..