Abstract: A geared parallel manipulator of the SCARA type is provided that consists of a pair of motors, each driving in a controlled manner a pinion. The two pinions mesh each with a rack, said two racks being joined together via a revolute, or via a flexure hinge. The proposed parallel manipulator is simple in design and can be fabricated inexpensively of stamped sheet metal or of extruded parts. It can also be fabricated as a microelectromechanical system (MEMS) using thin film technologies.
Abstract: A yarn tensioning device capable of delivering yarn under tension from a spool to a braiding, weaving or knitting machine consisting of a base and a center rod mounted perpendicular to the said base serving to locates the spool while allowing it to pivotally rotate. The device further includes a pawl jointed to the base either via a pin joint or via a flexural hinge and operates in conjunction with a ratchet solidly attached to the spool. The device further includes a compliant yarn guiding means which ensure that yarn reels off at an essentially constant tension. The yarn reel-off tension can be adjusted by modifying the operating length of a stiffening spring using a screw and jam-nut pair, and by limiting the maximum deflection of the compliant yarn guiding means.
Abstract: The restretchable stencil frame according to the present invention consists of a metallic stencil foil mounted on a rectangular frame fabricated of tubular material or C-channel. Each corner of the frame is provided with one screw-actuated conical expander and one counterplate serving to biaxially tension the stencil foil. To ensure uniform stretching of the stencil foil, areas of increased elasticity are provided to the corners of the frame and to the foil itself in the form of oriented slots, cuts, holes and combination thereof.