| 摘要 |
303,161. Bundy, H. W. Dec. 30, 1927, [Convention date]. Tubes.-A helical fin is applied to a preformed tube 1 by means of a pair of pressure rolls 5, 6 to which the fin stock 2, 3 is fed, the rolls engaging the strip stock with sufficient pressure to compress it with the greatest compression at the outer edge of the fin portion 2 so as to give it the curvature necessary to grip the said tube. The rolls 5, 6 are arranged substantially at rightangles to each other and are mounted on shafts 7, 10 respectively which are rotated by a shaft 12 through suitable gearing, and the shaft 10 is journaled in an adjustable block 15 so that the roll 6 can be moved towards and away from and angularly with respect to the roll 5. The fin stock is preferably fed to the winding head in a flat strip form and has the L-shape section imparted to it by being drawn through dies 20,. 21 under the action of the pressure rolls. The winding-head is provided with interchangeable lead dies 26, each having a slanting surface 27 which determines the pitch of the fin 2, so that several convolutions of the fin stock may be arranged to abut, overlap, or be spaced apart, and also feeds the tube to the said winding head. The tube may be completed by dipping it in a bath of solder. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a construction wherein the adjacent convolutions of the stock are arranged to overlap and the preformed tube is dispensed with, an arbor being used during winding. This subject-matter does not appear in the Specification as accepted. |
