Patent GB-103293-A (GB)
Title: Improvements in or relating to Apparatus for Electric Welding.
Inventor: MURRAY THOMAS EDWARD
IPC: B23K11/24
Filed: 1917-01-04
Abstract: 103,293. Woodrow, H. R., and Murray, T. E. Jan. 12, 1916, [Convention date]. Heating by electricity. - Spokes are welded to projections from a hub in a welding-machine in which the hub is clamped in a turret electrode manually brought into and out of contact but controlled for clamping- pressure by electrically-actuated toggles. The spokes are automatically fed to, and clamped in, their electrode, and upsetting-pressure is applied through a third electrically-actuated toggle. The machine has both direct and alternating-current supply, the circuits are closed in proper sequence by a triple-contact hand-operated switch, and the duration of the welding-current is automatically controlled by a time-lag device. The hub blank a, Fig. 17, is placed between turret electrodes 30, 26, Fig. 7, the electrode 26 being notched to engage a hand-operated index bolt 29. On raising a hand-lever 61 to the position shown, the coupling-rod 60 permits the rod 31 carrying the upper electrode to descend by gravity. The switch E, Fig. 18, is moved to its first position, making contact at F and connecting an electromagnet 43 to direct-current supply at D. A bar 45, Figs. 7 and 8, is thus raised, together with rods 48, 49. As the collar 101 rises with the bar 49, the rod 87 is permitted to descend, closing electrodes 86, 72 on a spoke. Leaf springs 102 secure electrical contact between the two parts of the electrode. Struts 54, 96 are raised by the bars 48, 49 to act upon double toggle mechanism 34, 92 to clamp the hub and spoke. The spokes are fed by a shoot to the clamps by mechanism mounted together with the electrode or clamp 72 on a table 64 sliding in guides. The lowest spoke rolls into a support 65, Fig. 10, and is arrested by a ledge 66. A bell-crank connected by pin- and-slot mechanism to the rod 87 acts through a spring on a lever 82, provided with a separate retracting-spring, to advance a plunger 74, which pushes the spoke through a flared opening 70 and into the clamp 72. An offset member 110 carried by the rod 87 then raises a stop 109 to prevent end movement of the spoke in the clamp during the application of upsetting-pressure, which is applied on the switch E making contact at G and energizing an electro-magnet 116 acting through a lever 120, Fig. 18, and double'toggle 123 on the table 64. To facilitate this motion, the upper electrode is in two parts, with a roller bearing interposed to permit the lower part to move with the spoke. The switch E is then moved to the third position, making contact at H, and energizing a solenoid P to close a switch J and supply alternating current to a selected portion of the primary winding of the welding-transformer Y. At the same time, a transformer X supplies the series coil d of a watt-meter relay set to close a switch e after a predetermined interval. The shunt coil c is connected across the main at the switches B, J. When the switch e closes, the coil L is energized and the switch I opened, breaking the welding circuit. The switch E is then opened, resulting in the return of the toggle-operated members As the lever 82 returns, contact is made at 126, 127, and the switches are reset.