| 摘要 |
1,121,950. Screws. NYDQVIST & HOLM A.B. 9 March, 1967 [11 March, 1966], No. 11211/67. Heading F2H. A long screw comprises a number of screw sections 1-4 in the form of externally threaded sleeves arranged in end-to-end contact, the screw sections being secured together by unhardened iron bars 5-7 inserted in the sleeves in which they are retained by shrinking the sleeves on to the bar or by a binding agent. The threads of adjacent sections are properly located by a nut screwed on one of the sleeves and provided with an indicating device which engages the ends of the threads of the adjacent sleeve. |
