| 摘要 |
641,611. Pneumatic tyres. STANDARD TELEPHONES & CABLES, Ltd. Oct. 31, 1947, No. 29102. Convention date, Feb. 13. [Class 144 (i)] [Also in Group VIII] A thermo-plastic air-tube, or other tube or pipe formed with a lap-joint, has the ends fused together by the use of high-frequency dielectric heating, a spacing-member being inserted through the valve or other hole in the tube to hold the walls apart and to take the pressure of the external electrodes. As shown in Figs. 2 and 3, the spacer consists of a rod having a flat head 8 which is inserted through the valve-hole 4 in the tube 1 and positioned at the lapped ends 2, 3 to be clamped between the electrodes 9, 10. Figs. 4 and 5 show a modification in which the spacer-head 15 is of semi-circular shape and forms the inner electrode to co-operate with a mating electrode 16. Either of these electrodes may be replaced by a roller adapted to traverse the joint. Fig. 8 shows a further modification in which the electrodes are formed by rollers 23, 24 which may be geared to rotate the tube 2 around a fixed spacer 27. In a still further modification, the spacer is in the form of a roller around which the tube is rotated between a pair of fixed electrodes. |
