Patent GB-282244-A (GB)
Title: Improvements in and connected with heat transmitting tubes
IPC: B21C37/26
Filed: 1926-09-16
Abstract: 282,244. Still, W. J. Sept. 16, 1926. Tubes. - Cooling or heating tubes as described in Specification 271,122, [Class 64 (iii), Surface apparatus &c.], have their heat conductivity from inside to outside increased by securing spirally to the tube by the edge a flat ribbon of wound heat conducting wire, the wire spiral being formed first on a mandrel in contact with an inclined surface which pushes the spiral off the mandrel as it is formed. The flat spiral ribbon is bound by a wine lying in the middle of its coils and secured at both ends on the tube, the whole being subsequently fused in place, e.g. by soldering. The binding- wire itself may be made of solder. The wire ribbon 26 is first formed by a bobbincarrying rotating dish 16, Fig. 1, which winds the wire around a fixed mandrel 22 of oblong cross section, the coils formed being gradually forced off the end of the mandrel by the pressure of the fresh wire being coiled on against a washer 23. The binding-wire 25 is led from a spool through tensioning and flattening rollers 49 through the hollow spindle 11 and along the bottom edge of the mandrel and the end is fixed to a pin on the spindle carrrying the tube 27 which is to be coiled with ribbon. The tube 27 is held in a chuck secured to a hollow spindle 31 and is slowly rotated by gears 32 from the screw 35 so that the ribbon 23 coming off the end of the mandrel may be wound circumferentially on the tube. This circumferential winding, however, becomes a spiral by causing the tube to travel axially backwards by having the whole tubegripping and rotating mechanism mounted on a head 37 which is traversed along a bed 36 by a screw 35 when a split nut is closed around the screw by a hand lever 59. The axial speed of the tube is varied by changing the driving sprockets 30, 39 of the screw 35, while the circumferential rotational speed is altered to vary the pitch of the ribbon by changing the gear 32. The tube is supported close to the mandrel by a fixed head 43. The under edge of the ribbon may be cut flat to fit the tube by attaching a milling cutter under the mandrel or the tube itself may be spirally corrugated. When the tube is sufficiently coiled the bobbin dish is stopped but the tube is kept rotating until a couple of layers of binding wire is drawn out which is then secured to the tube cut off. A pedal 157 is then operated which slides the traversing table 36 and moves the tube sideways from the mandrel. The lever 59 is then operated to free the head 37 from screw 35 so that it can be slid back carrying the tube with it. On releasing the pedal 157 a spring returns the traversing table 36 to axial alignment. The mandrel is adjusted to the best angle to the tube by pinching screw on the tail piece 165. The tension on the binding wire is gauged and adjusted by a weight 70 sliding on a lever arm. A spot welding insulated arm can be attached to the tube arm 43. The chuck 28 for holding the tube has spring jaws opened by screwing a cone between them by the fly nut 30. The rollers 49 are eccentrically mounted to adjust for the amount of flattening and tension of the wire. The wound tube is then soldered by lowering over a long tubular burner until the burner projects out at the top. The burner is then lit and the tube is lifted off slowly thus heating it from top to bottom and melting the solder wire and soldering the ribbon to the tube.