| 摘要 |
1,168,478. Skelping. WESTERN ELECTRIC CO. Inc. 11 Nov., 1966 [12 Nov., 1965], No. 50644/66. Heading B3E. A forming apparatus for imparting a transverse curvature to a longitudinally moving corrugated strip by passing it through a plurality of stages each comprising a pair of forming rolls, the rolls forming each pair being freely rotatable and having curved peripheral forming surfaces, is characterized in that the average radius of curvature imparted to the ribbon by the first pair of rolls is substantially equal to the product of the number of stages and the desired final radius and the average radius of curvature imparted by each succeeding stage is substantially inversely proportional to the number of the stage, the final stage imparting the curvature having the desired final radius. Thus, for example, with five stages the profile radius of each stage is respectively 5, 5/2, 5/3, 5/4, and 1 times the desired radius of the tube. A transversely corrugated strip 12 of copper bonded to tin-plated steel is given a transverse curvature by passage between pairs of rolls 38, 40 and 44, 46. A conductor 16 carrying spacers is fed down a tube 20 into the thus-formed trough. Pairs of rolls 52, 54, 60, 62 and 64, 66 then bend the strip 12 up into tubular form about the conductor 16. The rolls are adjustable and have ridges formed thereon against which the edge of the strip 12 abut. The profiles of the rolls 44, 46 may have smaller radii of curvature at the edges that at the centre. The strip thus formed into tube form 26 may then pass beneath a vertical wheel 136, Fig. 10, having a knife edge 140 engaging the edges of the strip to position the seam. The edges are then overlapped by rolls 76, 78 and the tube sized by rolls 76, 78, 80, 82 and 88, 90 before soldering the seam. |
