Patent GB-163416-A (GB)
Title: A method and apparatus for welding tubes
IPC: B23K5/06
Filed: 1920-02-05
Abstract: 163,416. Percival, S., (Davis-Bournon- ville Co.). Feb. 5, 1920. Tubes.-In making tubes with fusion or pressure-welded longitudinal seams by the use of an oxyacetylene or like flame, the open tube in its passage through the machine is bent between holding devices so that a bow is formed beneath the flame, which is greater than would be caused by longitudinal expansion due to heat, so that contraction on cooling results in the production of a straight tube in a condition of slight longitudinal compression. The tube is then finished by a pair of sizing rolls. The tube is fed by rolls 48, 49, Fig. 7, the latter of which has a central guide fin 51, between a pair of holding rolls 59, 60, and a pair of sizing rolls 98, 99, a bow being formed beneath the torch 66 by placing the passes of either the rolls 59, 60 or the rolls 98, 99 out of alignment with the pass of the rolls 48, 49. The feed rolls are adjustably mounted in standards 25, 26 on a frame 27, which is adjustable by a screw so that the rolls may be moved into close proximity with the rolls 59, 60 to avoid the twisting of the open seam. To increase the range of this adjustment the bearings at one end of the feed roll shafts are carried by arms 39, 40 pivoted at 41, 42 to the standards 26. The bearings 32, 33 at the other end are carried in a slot in the standard 25. The lower bearings rest on adjusting screws 35 and the upper bearings are simultaneously adjustable bv a pair of screws 34 connected by a chain. The upper and lower bearings are separated by springs 36. The torch 66 is movable by a hand-leves 63 horizontally and vertically on a bracket 62 carried by an arm 64, which is pivoted at 65 so as to adjust the longitudinal position of the torch. The torch may have two parallel rows of jets impinging on the metal just back of the seam, and may also have one or more central jets for smoothing the weld as described in Specification 102,431, [Class 83 (iv), Metals, Working]. The rolls 59, 60 which in the case of fusion welding are used to hold the tube against lateral expansion or to squeeze up the metal to strengthen the weld and in the case of pressure welding are used to effect the weld, are carried by shafts 57, 58 which are vertically adjustable independently, by screws 75, 76 so as to correct the relative position of the edges of the tube in case they are out of alignment. These screws preferably act through a plate 77 so that rotation of the shafts does not act on them. The shafts are mounted in box bearings 81, 82 separated by a spring 83, and also in bearings 67, 67<a> which are mounted on pivots 69 so that the shafts may be tilted by screws 79, 80 through a handwheel 84 and spur gear in order that compression takes effect mainly above the horizontal diameter of the tube so as to hold the tube in somewhat flattened relation instead of pinching up the seam. The tube is finally passed through sizing rolls 98, 99 carried by bearings separated by springs 114, the lower bearings resting on adjusting screws 115 and the upper bearings being adjusted by screws 110 connected by a chain. The sets of rolls are driven from a motor 2 connected by belt and change speed gear to a shaft carrying a worm, which is in mesh with a worm wheel on the shaft 11, Fig. 2. The rolls 48, 49 are driven from the shaft 11 by spur gear, the wheel 13 of which is carried by an arm 15, moved on its pivot by hand and secured in adjusted position at 19. The sizing rolls are similarly driven, the wheel 14 being mounted on a similar pivoted arm 16. The rolls 59, 60 are driven from the shaft 11 by spiral or skew gears 53, 54, 55, 56 the gears 55, 56 being carried by sleeves 71, 71a mounted in the pivoted bearings 67, 67<a> and feathered to the shafts 57, 58. Two pairs of idle compression rolls 91, 93 may also be used, being laterally adjustable by screws and also set at appropriate intermediate levels by packing pieces. The rolls and torch tip are interchangeable for tubes of different sizes.