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公开(公告)号:US4716656A
公开(公告)日:1988-01-05
申请号:US29767
申请日:1987-03-24
申请人: Neil A. Maddock , David K. Thomas
发明人: Neil A. Maddock , David K. Thomas
摘要: A stylus (15) for contacting a workpiece (13) to sense its position is suspended on a movable member (16) within a fixed housing (10). The suspension is by means of three connecting units (20, 30, 40). Taking the connecting unit (20)as an example, the movable member (16) is connected to an intermediate member (22) by a first pair of links (21), while the intermediate member (22) is connected to the fixed housing by a second pair of links (23). The pairs of links are rigid in tension and compression so as to prevent rotation of the stylus about a respective one of the three orthogonal axes X, Y, Z. Nevertheless, the links permit translational movement along all three axes. The similar connecting units (30, 40) likewise permit translation on all three axes, while preventing rotation about a respective one of the axes. The use of two pairs of links (21, 23) with a rigid intermediate member (22) is equivalent to the use of a much longer single pair of links without such an intermediate member, and therefore facilitates a more compact construction of the probe for a given range of translational displacement of the stylus (15).