Improvements in or relating to methods of forming seatings in tubes

摘要

842,267. Making furniture; frameworks; shearing; forging; welding by fusion; angular bending; bolted joints; soldering. CRUSON, I. P. Feb. 22, 1957 [Feb. 29, 1956; July 13, 1956], No. 6033/57. Classes 83 (2) and 83 (4). [Also in Group XXXI] In a method of making a seating on a tube to obtain a joint with another tube crossing the first tube, e.g. a joint for metal furniture, bicycle handlebars, constructional and other framework &c., the first tube wall, while supported in a troughed matrix as deformed by a die-tool which corresponds to the shape of the required seating and enters a further transverse trough in the matrix. A seat 9 is formed on a tube 7, Fig. 3, lying in a cavity 211 of a matrix 22, Fig. 6a, by a die-tool 23, Fig. 6b. The matrix 22 may mount a knife 24 to cut the seat as it is formed to make half-seats 14 at the ends of tubes. A joint with a tube 1 or a bar 18 is completed by welding at 11, 12, 13 or 15, 17. Straight tubes may cross at any inclination or during seating in modified dies the first tube may be bent to an obtuse angle so that the seating for the second tube is either in a plane parallel to that defined by the inclined parts of the first tube, a plane perpendicular to that plane or in some intermediate plane therebetween. Double seats may be made and the joint may alternatively be secured by bolting a tube to the seating. In a modification, single-walled seats 60 and 61, Fig. 18, are formed by forcing the walls of a tube 59 outwardly, using a chisel-shaped die 63, Fig. 17. Alternatively, one wall only may be penetrated to prepare a T-joint, the forced wall of the tube being doubled back during the piercing to form a double thickness seat, the joint being completed by hard and soft soldering.