Patent GB-797137-A (GB)
Title: Chassis frame with tubular side frame members for automobiles
IPC: B21C37/18
Filed: 1955-06-21
Abstract: 797,137. Making automobile chassis frames; welding by pressure and fusion; angular bending; stamping. BUDD CO. June 21, 1955 [June 21, 1954], No. 17872/55. Classes 83 (2) and 83 (4). [Also in Group XXXI] A tubular side-frame member 2, Fig. 3, for an automobile chassis, adapted to extend through a mid-portion M and the rear wheel portion R, Fig. 2 (not shown), of the chassis and having a smaller diameter at the rear wheel portion, is made from a single sheet-metal blank 16, Fig. 11, of tapering width, which is formed into a tube and its edges joined by a single seam weld, the tube being then bent upwardly to form the rear-wheel portion. The blank 16 may taper all along its length, Fig. 11, or it may have two tapering portions 19, 21 and a parallel-sided mid-portion 20, Fig. 15 (not shown). For forming the tube, the blank is first folded between dies 38, 39, Fig. 23; a mandrel 40, Fig. 24, is then inserted and the folded blank is rolled between grooved rolls 41, 42 to complete the tube. The circumference of the rolls is at least equal to the length of the tube and the width of the grooves varies around the circumference to suit the taper of the tube. A flat portion 44 of each roll permits the mandrel to be withdrawn rearwardly whilst the tube is gripped between jaws 46. The tube 2 is then held in a welding fixture 47, Fig. 32, and its edges are welded by submerged arc welding using an electrode 49. Alternatively the edges of the tube may overlap and be united by resistance welding. Thereafter the tube is gripped by clamps 52, Fig. 33, and bent to form the rear wheel portion by sweep rollers 50, 51 of which roller 51 first pivots about the axis of roller 50, Fig. 3, to bend the tube upwardly; then roller 50 pivots about the axis of roller 51, Fig. 34 (not shown), to bend the tube downwardly. The rear end of the tube is finally bent in dies 53, Fig. 35 (not shown), and is bifurcated and flanged by cutting slots 54, Fig. 41, using pincer cutters 55, Fig. 40 (not shown), holding the tube end in a die 56 and opening the end by a conical die 58. The chassis, Fig. 3, comprises a pair of tubular side frame members 2 secured by welding 22, Fig. 6 (not shown), to a front end unit 1 formed of upper and lower stampings 11, 12 and preferably constructed as disclosed in Specification 752,506, [Group XXXI]. Cross-members 3, 4, brackets 5, 6 for securing the body and brackets 7 for the rear spring shackles, are provided; cross-member 3 and brackets 6, 7 are secured to the side member by spot welding, Figs. 36-38 (not shown). Fusion welding 70, Fig. 8 (not shown), may additionally be used for the brackets 7. In one embodiment of securing a bracket 77 to the side frame member 2, Fig. 39, holes are provided in a flange 78 of the bracket, and weld rivets 79 are passed through the holes and welded to the member 2 by electrode 80. When used for cars having open bodies the chassis frame may have sheet-metal side reinforcements 28, Fig. 18, welded thereto; in this case the body fixing brackets 5, 6 are eliminated and the fixing holes 36 are provided in the reinforcements. The chassis frame may be shipped in parts, Fig. 4 (not shown), which are welded together on final assembly.