| 摘要 |
A printing screen has a screen fabric extending across a frame comprising four rollers in a rectangular array, the rollers having longitudinal slots with securement strips engaged in the longitudinal slots and thereby securing edge portions of the screen fabric to the rollers. Corner members interconnect the four rollers and fasteners at the corner members are adjustable to releasably secure the rollers against rotation relative to the corner members. Connectors between the corner members and the rollers are freely rotatable relative to the corner members, on release of the fasteners, and fixed relative to the rollers. A screen fabric tensioning apparatus has a support structure shaped to support the printing screen and pneumatic cylinders mounted on the support structure and operatively connected to the connectors through a rack and pinion for rotating the rollers to tension the screen fabric.
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