| 摘要 |
1,041,804. Boring heads; dashpots. A. HONSBERG. June 4, 1964 [June 4, 1963], No. 23247/64. Headings B3B and B3C. A boring head comprises a sleeve 2, axially and rotatably slidable in a casing 1, a tool spindle 13, rotatably carried in the sleeve and worm drives 4, 5 and 17a, 18, for respectively rotating and feeding the sleeve. Sleeve 2 has a guiding portion 2a of non-circular crosssection, and atomized lubricating oil is supplied through apertures 3, 3<SP>1</SP>, so that a small axial pressure is exerted which opposes the feed of sleeve 2. Worm-wheel 5, rotates sleeve 2 through a ring 6 screwed to the sleeve and keyed to a groove 5<SP>1</SP> in wheel 5 by a key 6<SP>1</SP>. Tool spindle 3 is rotated by a shaft 14 of polygonal cross-section, which co-operates with a corresponding bore in spindle 13, and in a sleeve 16, the latter being driven by a pulley 15. The axial feed of sleeve 2 is provided by worm and wheel 17a, 18, which rotates an externally threaded sleeve 17, screwed to an internally threaded non-rotary, but axially slidable, sleeve 19. The feeding movement of sleeve 19 is transmitted to sleeve 2 by a ring of spring urged balls 23 arranged in peripheral grooves 22 in the sleeves. The feed movement is also transmitted to shaft 14 by a ball bearing 26, and when sleeve 2 abuts a ring 10 balls 23 are pushed out of the groove in sleeve 19. The feed is shut off by stops which co-operate with a torque limiting switch. A plurality of heads may be used to form a multi-spindle boring unit, and the pulleys 15 may be driven by a common belt, from a single motor. The worms may be coupled together, or may each be driven by a separate motor. |
