| 摘要 |
PURPOSE:To make it possible to securely hold a sheet of material on a printing table, even if the fed material is distorted by such an arrangement wherein material attracting parts are installed in a negative pressure attraction unit so that they are slightly protruded above the surface of a printing table, and they are arranged so that they can be moved vertically by the negative pressure attraction of the negative pressure attraction unit. CONSTITUTION:When a thin plate M for a printed circuit board, for example, is fed and positioned at a specified position on a printing table 1, it is securely held on the table 1 by the negative pressure action of a negative pressure attraction unit 2. A negative pressure air hole 2a is provided in each negative pressure attraction unit 2 of the printing table 1, and a material attracting part 3 covering the air hole is installed in the unit so that it is protruded from the printing table 1. This attracting part 3 is formed into bellows-like shape by elastic rubber material and it is provided with an opening 3a at its upper portion and a connecting hole which is to be connected to the air hole 2a at its lower portion. The material attracting part is constantly brought to conact with the back of a sheet of material at a position higher than the printing table and it is capable of holding the sheet of material on the printing table safely and positively as it contracts by the attraction of negative pressure, even if the sheet is distorted. |
