| 摘要 |
1294845 Indexing; grinding; jointing by forging MINSKY OPYTNY ZAVOD SPETSIALNOGO KONSTRUKTORSKOGO BJURO No 3 10 Aug 1970 [14 Aug 1969 (3)] 38413/70 Headings B3B B3D and B3H An indexing mechanism includes an indexible plate 1, a locating plate 2 and an arrangement of balls 5 fixed to the latter for co-operation with indentations 3 in the former, the distance between adjacent indentations being equal to, or a multiple of, twice the radius of the indentations and the balls being seated in the locating plate 2 to a depth exceeding their radius. In operation, the indexible plate 1 is retracted from the location plate 2, indexed, and reengaged with the locating plate whereupon the balls 5 enter appropriate indentations 3 to locate the plate 1. In another embodiment (Fig. 3, not shown), an arrangement of three coaxial plates is used. The pitch of indentations on one plate (6) is larger than on the other plate (7), these two plates being separated by a common locating plate (8) with balls on both of its surfaces. In operation, plates (6) and (8), for example, are indexed relative to plate (7), then plate (6) is indexed in the reverse direction relative to plates (7) and (8). Thus indexing through an angle, or its multiple, equivalent to the difference between the two pitches is attainable. In a further embodiment (Fig. 4, not shown), a common indexible plate (12) is interposed between two locating plates (10, 11). In a method of making the mechanism (Figs. 5 and 6, not shown), the indentations are made by pressing balls into the surface(s) of the indexible plate, and into the surface(s) of the locating plate to a depth exceeding the ball radius. The indentations are formed as a result of local plastic deformation, and are of a depth less than the ball radius. By pressing the balls into the locating plate, raised annular lips result around each ball. Subsequently, as the indexible plate is pressed against the locating plate, these lips are deformed and flattened whereby the balls are firmly embedded in the locating plate. The mechanism can be used in universal assembly jigs, swivelling stands of milling and drilling machines and in spline-grinding machines (to set the arbor at a definite angle). |
