GB628646A - Improvements in or relating to an electric welder and a pressure head therefor - Google Patents

Abstract

628,646. Welding; welded joints. REPUBLIC STEEL CORPORATION. Feb. 28, 1947, No. 5818. Convention date, Dec. 15, 1944. [Class 83 (iv)] An electric resistance butt-welding head comprises a member 15 positively driven to a lower limit, urging the work-pieces 3, 40 together by compressing a spring 25, and on softening of the contacting work-surfaces the spring 25 extends and upsets the weld by further movement of the inner sliding electrodecarrier 43 independently of the driven member 15. The sleeve 17 of the cam or fluid-pressure operated member 15 supports a ring 26 surrounding a tube 35 carrying a double flanged head 36 and sliding in a bearing 23 of an upper plug 20 of the sleeve 17. The spring 25 engages the plug 20 and the upper flange 48 of the head 36 under compression, and the head 36 carries guide-pins 46 supporting the die-holder 43 and working in resilient guide tubes 27b of the ring 26. The sleeve 17 carries insulated rollers 5 engaging vertical vee guides 4, of the frame 8. The head 36 is slotted to receive separate silver-plated copper current-conducting leaves, Fig. 3 (not shown), bolted to the frame 8. Operation. The sleeve 17 descends carrying the head 36 until the upper work-piece 40 contacts the lower piece 3, when side contacts, Fig. 11 (not shown), complete the weld-timer circuit, and the spring 25 is compressed until the ring 26 engages the lower flange 49 of the head 36. When the junction softens, the head 36 descends and forms the upset until the upper flange 48 engages the ring 26. The lower workholder 2 is designed for plate to tube and tube to tube welds with or without external and internal fillets, Figs. 17 to 22 (not shown).