| 摘要 |
972,814. Bolt-hole &c. bushes. ROSAN ENGINEERING CORPORATION. Jan. 30, 1961 [July 25, 1960], No. 3477/61. Heading F2H. [Also in Divisions B3 and B4] A bolt-hole, nut &c. bush 10 comprises a thin-walled body with internal and external threads and means for locking the bush in the bolt-hole &c. The external threads 14 have shallow roots 15 and at least one of the internal threads 16 is removed by a counterbore 20 which facilitates expansion of the neck of the bush into locking engagement with the bolthole. This may be counterbored at 44, and the top thread or threads of the steel, stainlesssteel or aluminium alloy bush may be formed with teeth 34 of larger diameter than the threads 14. Grooves 30 in the threads 16 receive the hexagonal driving end of a tool 66 (see Divisions B3 and B4) which has an enlargement 70 drivable into the counterbore 20 for expanding the neck. The bolt-hole threads 38 also are of shallow form. One or more of the threads 16 may be deformed inwardly and slightly axially to form locking threads. The bush may have a closed lower end, Fig. 9 (not shown). In a further form, Fig. 10, driving slots 128 are provided only in the counterbore. Alternatively, a four-cornered driving recess may be formed with corners 144, Fig. 14 (not shown), at about 120 degrees. The bush may taper, Fig. 16 (not shown), or have a locking neck at each end for engaging a nut 162, Fig. 17. The bush may be made self-tapping by tapering the end threads 274, Fig. 27, and forming recesses 272, radial openings, Fig. 29 (not shown), or axial slots, Fig. 33 (not shown). If the recesses 272 &c. are omitted, the metal of the bolt-hole may be displaced by the bush to form screw-threads. In Fig. 34, the bush is mounted in a dome-nut 300 having a serrated locking flange 306 bent down to deform the material of the sheet 304 into a groove 308. A tabular statement is included, giving thread sizes and bush thicknesses. |
