| 摘要 |
992,475. Screwing up attachments. C. I. WILLIAMS. Nov. 14, 1963 [July 22, 1963], No. 44992/63. Heading B3N. A coupling for connection to a power-driven wrench when driving a stud 11, comprises a preferably hexagonal body 13, a screwed bore 12, and a ball 15 held in the bore by three upsets 20, as positions 17-19. |
