| 摘要 |
1. Indexing and locking mechanism for a rotary turn table (1) on a table carrier body (2) comprising : - an indexing and locking ring (9) fastened to the rotary table, coaxial to the latter, and provided with notches (26) of a generally V-shaped section cut in a main marginal surface of revolution (31) adjacent to an auxiliary marginal surface of revolution (32) into which the said notches lead laterally, the flanks of these notches (26) being divergent, from the bottom of the notches, both towards the main marginal surface of revolution (31) and towards the auxiliary marginal surface of revolution (32), - a plurality of indexing and locking balls (25) partially engaged permanently respectively in (axial or radial) rectilinear grooves (23), likewise of generally V-shaped section, formed in a surface of revolution of the table carrier body (2) coaxial to the indexing and locking ring (9) and situated opposite the auxiliary marginal surface of revolution (32) of the indexing and locking ring, the flanks of the said grooves (23) in the table carrier body (2) being divergent from the bottom to the outside, the balls (25) being adapted to occupy selectively along the said grooves either a position locking the table, in which they are also partially engaged in the notches (26) in the indexing and locking ring (9) (figure 3) or a position in which the table (1) is freed and in which they are situated outside the said notches (26) (figure 4), - and locking control means (6) for urging the indexing and locking balls (25) along the grooves (23) in the table carrier body (2), characterized in that the locking control means are composed of a cam (6) mounted for pivoting coaxially to the indexing and locking ring (9) and also having, on the one hand, a main marginal surface of revolution (35) facing the notched main marginal surface of revolution (31) of the indexing and locking ring (9) and provided with a number of notches (27) equal to the number of grooves (23) in the table carrier body (2), and, on the other hand, an auxiliary marginal surface of revolution (36) adjacent to the main marginal surface of revolution and into which the notches (27) in the cam lead laterally, the auxiliary marginal surface of revolution (36) of the cam being situated in the extension of the auxiliary marginal surface of revolution (32) of the indexing and locking ring and also opposite that surface of revolution of the table carrier body (2) in which the rectilinear grooves (23) are formed, the notches (27) in the cam having a likewise generally V-shaped section with flanks which diverge, from the bottom of the notches, both towards the main marginal surface of revolution (35) and towards the auxiliary marginal surface of revolution (36) of the said cam, in such a manner that in an angular position of the cam (6) corresponding to the locking of the rotary table (1), the parts of the main marginal surface of revolution (35) of the cam which are situated between the notches (27) on that surface hold the balls pressed against the flanks of the notches (26) in the indexing and locking ring (9) against the flanks of the grooves (23) in the table carrier body (2) while in an angular position of the cam (6) corresponding to the unlocking of the rotary table (1) the balls (25) can pass completely out of the notches (26) in the indexing and locking ring (9) and penetrate into the notches (27) in the cam, thus freeing the ring for rotation. |
