Patent GB-1451495-A (GB)
Title: Welding unit
IPC: B23K9/30
Filed: 1973-12-20
Abstract: 1451495 Welding by fusion FIVES-CAIL BABCOCK 20 Dec 1973 [21 Dec 1972 19 Sept 1973] 59097/73 Heading B3R A gas-shielded or submerged arc welding consumable electrode guide and contact device 4 is oscillated transversely of a longitudinal weld path, the amplitude of oscillation is limited by contact of the device 4 with a weld preparation groove wall, and means are provided whereby a dwell is provided at each end of the oscillation path. As shown, the device 4 is carried by a carriage 14 transversely slidable in a frame 11 mounted on a longitudinal slide 2. The carriage 14 is acted on by a double-acting liquid, or, as shown, pneumatic cylinder 17. The device 4 has adjacent its extremity a roller 60 (e.g. of hard steel) which determines oscillation amplitude of said device by engaging a wall of a weld preparation groove and may be interchangeable for electrode/wall distance variation. The cylinder 17 is reciprocated under control of a distributor valve 503. Control of compressed air flow to the cylinder 17 hence oscillation traverse speed of the device 4 is by adjustment of a flow regulator 511. The distributor 503 is controlled by pressure or flow detectors 521, 522 arranged to sense abutment of the roller 60 and to act via variable time-delay relays (e.g. pneumatic) 523, 524 to reverse cylinder 17 energization after dwells. Such dwells may be arranged to be the same or differ, and are indpendent of amplitude or traverse speed. The action of the cylinder 17 may be blocked so that the roller remains in continuous engagement with one groove wall. In the event of lateral deviation of the longitudinal working path, e.g. in a path of sinuous form, oscillation reversals are accommodated as a result of roller 60 contacts until the deviation reaches an amount such that the carriage actuates one of micro-contacts 19, 20 causing stopping of the carriage and emission of a sound and light signal indicating need for re-centering of the carriage by the operator. The consumable electrode guide and contact device 4 comprises two arms 42, 43 insulated from each other and supported by an insulating (e.g. ceramic) member 45 adjustingly rotatable about a vertical axis 46. The arm 43 receives a welding current supply cable and has an electrode contact member 52 of conductive hard alloy. The arm 42 supports the wall-engaging roller 60 and an electrode presser roller or, as shown, shoe 53 (e.g. ceramic) carried in a casing 54 acted on by a leaf spring 56 by way of a push rod 58. Electrode wire 44 from a straightening and feed device 10, Fig. 1, is fed through an insulating bushing 47 in the member 45 and between the contact member and shoe 52, 53. As shown in Fig. 1, feed/suction ducts 62, 63 for gas, flux or coolant are connected to the arms 42, 43, and the arm 43 and ducts 62, 63 are insulated against arcing as by glass wool tape or adhesive. In Figs. 4, 5 (not shown), tandem electrodes are accommodated by provision of a hinged, intermediate, double-grooved conducting member (65) disposed between the contact member and shoe 52, 53. By using two devices 4 arranged at 90 degrees to each other, and by suitable adjustment of the speeds of the carriages 14 and the time delays of the relays 523, 524, electrode sweeps as shown at A, B in Fig. 8 may be effected.