Patent ID: 7240580
Filing Date: 2007-07-10
Classification: F16L,Y10S,Y10T

Abstract:
1. A positioner having a central axis, a base and a stage providing for movement of the stage only along said central axis, with only a single degree of freedom, comprising: reference surfaces on said base and on said stage parallel to and facing each other in pairs, spaced apart laterally from one another; a rotor having a central axis with a plurality of external circularly cylindrical segments coaxial with one another placed between each said pair of reference surfaces; a first and a second suspension, each suspension comprised of flexible, substantially non-stretchable sheet material having a dimension of length and of width to form a pair of flat straps, the straps of each suspension being attached to a respective reference surface, with the straps of each pair extending in the same direction from the rotor, but on opposite sides of the rotor, and the straps of each pair directed in the opposite direction from the straps of the other pair, the straps of each pair being joined by a bight which abuts said rotor, as a single suspension, the bights being in abutment with a respective segment, and all of the straps being mounted to the rotor and in contact with a respective segment, whereby the rotor is trapped between the said suspensions, and is freely rotatable when the base and stage move axially relative to one another; each assembly of said surfaces, rotor and suspensions comprising a set, there being at least three of said sets, with the axes of the cylindrical segments forming a closed polyhedron when viewed in plan along the central axis of the positioner; said straps resisting, in shear, relative shifting movement of the base and stage in their respective planes, thereby as a group restraining the stage from lateral and rotational movement relative to the base, while permitting axial movement of the stage solely along the said central axis of the positioner.