Abstract: A tensioning frame (1) for stencils (9) formed of metal foils or plastic films, especially for stencil printing, provided at their margins (8) with perforations (10) for tensioning. The frame includes a tensioning device operated by a pressure medium for driving tensioning bars (5) that carry hooking pins (6) that engage the perforations of the stencil. The tensioning device is formed by an elastically deformable tensioning tube (4) disposed in a frame profile (2) and uniformly supplied with a pressure medium. The tensioning bars lie with the full length of their front sides in contact with the tensioning tube and with their back sides resting against fulcrum nubs (17) which in turn are supported against an extrusion (3) which closes the frame profile. The tensioning bars can be pivoted by inflating and expanding the tensioning tubes to stretch the stencil over a bridge (16) on the frame.

Abstract: A rotary slide valve (1) for selective delivery of pressurized air or vacuum to an apparatus (3), which permits a very precise delivery of vacuum or pressurized air through a control port (2), especially to a plenum (16) of an apparatus (3) for introducing a conductive paste into holes (22) in circuit boards (17). Two transfer passages (10 and 11) are disposed in a rotary slide (9) offset by 120.degree. around the axis of rotation, and transfer ducts (12, 13 and 14) contiguous with the rotary slide and communicating with the control port (2) and with inlet/outlet ports (7 and 8) are arranged in a reference plane likewise offset by 120.degree. around the axis of rotation.