| 摘要 |
<p>In a vacuum printer for the graphic arts having a bed, a blanket frame upon the bed including a flexible impervious blanket having a peripheral sealing bead, a glass frame including a glass, with the glass in snug flexing and sealing registry with the blanket bead defining a contact printing chamber, the glass frame being movably mounted for opening and closing movements relative to the blanket frame, and a vacuum source having a first vacuum conduit communicating with the printing chamber for evacuating it; the improvement which comprises a non-metallic base plate positioned within and yieldable mounted upon the blanket frame supportably underlying the blanket. A flexible apertured skirt at its outer and inner periphery is sealed respectively upon the blanket frame and the base plate, defining with the blanket a vacuum chamber connected by a second conduit to simultaneously evacuate the vacuum chamber for a limited interval, and regulate its vacuum level by the controlled flow air into the vacuum chamber during its evacuation.</p> |
