| 摘要 |
1,235,362. Intermittent gearing. R. J. PETROFF. 12 June, 1968 [12 June, 1967], No. 27956/68. Heading F2Q. A rotatable turret 22 having equi-spaced radial spindles 26 rotatably supporting rollers 25 is intermittently driven by successive engagement of the rollers by the cam track of a cam 12 rotatable about a cam axis 10a perpendicular to and offset from the turret axis 23a, the cam track providing turret dwell and turret movement to a successive dwell, the roller profile 29e (Fig. 3B) and the transverse cam track profile 40p being without points of inflection and having slightly differing radii of curvature, e.g. 3-5%, to give theoretical rolling point contact, and the cam track width providing clearance between the roller and the track idle sidewall at all points. As shown, the roller profile is convex and the cam track profile is concave, but the track profile may be straight (Fig. 11, not shown), or the roller profile may be straight frusto-conical and the cam track profile convex (Fig. 12, not shown), or the roller profile may be concave and the track profile convex (Fig. 12A, not shown). The cam track is cut by a cutter 40 driven by a high-speed motor 42, and having a cutter feed device 42a, the cutter assembly being pivoted about an axis 43 coincident with or close to the axis 23a of the turret. The difference in diameter between the roller and the cutter at line 29g is equal to the required clearance between the roller and the cam track idle sidewall. Preferably the cutter axis 41 is parallel to the required roller axis 26a and axis 43 is offset from axis 23a by 0.002 to 0.005 inch, but if axes 23a, 43 are coincident, axis 41 will be at a small angle to axis 26a. |
