| 摘要 |
<p>A perforating unit for making a stencil comprises a pin holding plate (1) and a support plate (2), the pin holding plate (1) being movable up and down on guide pegs (6) secured to the support plate (2). The plates (1, 2) are provided with matching matrices of through holes (3). Springs (9) disposed around the pegs (6) urge the two plates (1, 2) apart. An intermediate plate (10) is located between the pin holding plate (1) and the support plate (2). A channel (11) for receiving a plastics strip to be perforated is defined between the intermediate plate (10) and the support plate (2). In use, pins (5) are held in the holes (3) in the pin holding plate (1). The pins (5) are arranged in a pattern in which the plastics stencil strip is desired to be perforated. A plastics strip is placed in the channel (11), and a platten is placed over the pin holding plate (1) and depressed so that the pins perforate the plastics strip to form a stencil. The invention includes the use of the stencil in the sandblasting of security indicia into vehicle windows.</p> |
