| 摘要 |
534,263. Flexible tubes. SOUTH METROPOLITAN GAS CO., and PRESTAGE, A. J. Jan. 23, 1940, No. 1380. [Class 99 (ii)] A rubber tube has within it for preventing collapse a helical wire spring 2 of a diameter substantially less than that of the tube and attached at one or both ends to a collar 3 adapted to be pushed into the tube and gripped thereby. |
