| 摘要 |
The invention relates to punch assemblies (8) and is particularly concerned with the punching of holes in flexible photopolymer sheeting, as is used extensively in the printing industry. The nature of flexible photopolymer sheeting is such as to make the creation of holes particularly difficult, and hitherto the only effective technique that has been available is drilling the holes in the sheet. The object of the invention is to provide an improved means of providing holes in flexible photopolymer sheeting which objective is met by a punch assembly (8) comprising a hollow tubular punch member (10) which, at its operative end is correspondingly inwardly contoured at diametrically opposite sides, and a support plate (11) or die, the punch (10) being mounted above the support plate (11) for rapid axial reciprocal movement towards and away from the support plate (11) and there being a corresponding hole in the support plate for the passage of the punch (10). |
