Indexing and positioning device

An indexing and positioning device comprising:

• an inner ring;
• an outer ring disposed coaxially and closely around an outer side of the inner ring with an annular boundary therebetween forming a gap, said inner and outer rings having respective first surfaces disposed in the same plane, one of the inner and outer rings being fixed and the other ring being adapted to revolve relative thereto about the common axis thereof;
• a plurality of positioning recesses provided as depressions in said first surfaces at equal indexing intervals along, and straddling said boundary;
• each of said positioning recesses being in the shape of an inverted pyramid with an equilateral parallelepiped base constituting an opening edge of the recess, which is formed symmetrically on inner and outer sides of said boundary as symmetrically opposed inner and outer parts of the recess formed respectively in an outer edge rim of the inner ring and in an inner edge rim of the outer ring when said inner and outer parts are brought into mutually coincident register in an indexing position;
• a plurality of positioning members one of which is floatably accommodated within each of the positioning recesses;
• retainer means confining and guiding each of the positioning members;
• and a clamp ring operable to press the positioning members into the respective positioning recesses to thereby cause accurate and positive centering and positioning of indexing positions of the inner and outer rings relative to each other.