| 摘要 |
1396257 Drilling machines; beds and frames; workholders HADADY MACHINING CO Inc 7 Aug 1973 [21 Dec 1972] 37472/72 Headings B3C and B3B A centre-drilling machine comprises a frame 11, 12, a parallelogram linkage 20, 31, 32, 18 and a plate 34 for supporting a drill 35. The bar stock to be drilled is mounted in V-blocks 15, 16, the linkage is pivoted about pivots 21 by fluid pressure cylinders 26 until a clamp 24 abuts the top of the bar stock and clamps the latter in the V-blocks and the hydraulic drill 35 is fed through plate 34 by a rack and pinion 36, 37, so that drill bit 44 operates on the bar stock. Clamp 24 is free to pivot so as to be capable of clamping work stock at different diameters and drill bit 44 remains horizontally in alignment with any such stock due to the parallelogram linkage. Twisting of clamp 24 is prevented by a vertical bar 45 fixed to plate 34 and to a pair of horizontal bars 46. Twisting of drill 35 is prevented by two plates 42 connected through plate 34, by rods 43. |
