| 摘要 |
<p>1,010,837. Perforating. FRANCAISE POUR LA FABRICATION DES TOLES PERFOREES S.A. Jan. 30, 1964 [March 12, 1963], No. 4049/64. Heading B3W. A method of perforating sheet material by punching comprises causing a punch to penetrate the material under the combined action of pressure and vibration. The vibration frequency is between 20 and 170 c.p.s. and advantageously between 50 and 75 c.p.s. The direct pressure is irrespective of the thickness to be cut and is between 5 and 50 kg. per millimetre of cut perimeter. An example states that a hole 3 mm. diameter was punched in 50 kg./sq. mm. sheet steel 5 mm. thick using a direct pressure of 500 kg. as compared with an estimated force of 1500 kg. necessary without vibration. A press for carrying out the method comprises a frame 10, a work support table 7 and a bracket 13 supporting the tool head 14 which is secured to a block 15 comprising a jack 15 and vibrator. The tool head comprises a case in two parts 16a, 16b, a slide 17 carrying the punches 2, and a stripper spring 18. The tool 19a of a compressed air gun 19 extends through an aperture 16c in the case. The gun 19 is moved by the jack 15 as the punches penetrate the material.</p> |
