| 摘要 |
1532155 Workpiece clamping, copying EXCELLON INDUSTRIES 19 May 1977 [15 Nov 1976] 21081/77 Headings B3B and B3K In a routing operation in which a part 22 is machined from a larger plate 18 (or a plurality of parts 22 from a stack of plates 18) which is held positionally by tooling pins 23, and in which, when the routing tool 17 is approaching its initial start position with very little material left to be machined in the path 134 and the part 22 then tends to move laterally causing an incomplete removal of material from the edge of the part, there is provided a clamping means which comes into operation at the final part of machining to prevent the cut-out part 22 from moving. A vertically movable spindle head 11 is lowered at the start of machining by a pivotable arm 12 and pneumatic jacks 26 force down a clamping head 24 to engage the plate 18 with a first pressure whereby a low-friction ring 87 engages the plate 18 and slides relative thereto as the path 134 is machined. As the cutter approaches the start position the jacks 26 are pressurized at a higher pressure to collapse spring 89, 92 to engage a high-friction ring 74 with the plate 18 and part 22, and simultaneously a pin 95 is retracted to allow a slide plate 59 which carries the rings 87, 74 to move laterally relative to the spindle as the final part of the path 134 is machined away. The slide plate 59 can only move relative to the spindle a limited amount, and is biased to a centre position by at least four springs, e.g. 110, 113. Cuttings are removed from the head 24 by a suction pipe 37. |
