| 摘要 |
575,808. Flexible tubes. ROBERTS, F. T., and ROBERTS, R. E. April 6, 1944, No. 6502. Convention date, April 13, 1943. [Class 99 (ii)] Relates to a 'method of making a corrugated flexible tube having a tensioned metallic or non-metallic coiled spring embedded in its wall. The lining 10 of rubberized fabric is applied to a mandrel 5 and coated with adhesive or rubber solution, and a close-coiled spring 20 has its end'turns soldered together and secured on the tube by tape 35, the spring then being stretched to the position shown and its other end secured to -the tube A rubberized fabric tape, 30 may then be wound over the coils of the spring and the assembly is partly vulcanized. The tube is removed from the mandrel and a rubber bush 50, Fig. 14, mounted on a sleeve 55 is inserted in each end 'of the tube which is then mounted on a mandrel 60. A stockinette covering 40 carried by a tubular holder 65 is slid over the 'tube and the end of the covering is secured to the tube and bush by a tape 52. The holder 65 is withdrawn allowing the covering 40 to contract on to the tube, and the tube is corrugated by winding a cord between the convolutions of the spring. The tube is 'then finally vulcanized and the cord is removed. The lining and covering may be wholly of rubber and the spring may be of steel or of semihard rubber or of plastic material. The adhesive tape 30 may be dispensed with. |
