| 摘要 |
635,020. Gear - cutting. NATIONAL BROACH & MACHINE CO. Aug. 5, 1947, No. 21226. Convention date, Aug. 5, 1946. [Class 83 (iii)] [Also in Group XXIV] In gearing of the conical involute type in which the gear cone 11 is conjugate to a straight rack 10 a hollow lead modification is given to the flanks of the teeth in order to increase the area of contact when the gear is in mesh with another gear. The teeth involutes are formed by a pitch cylinder 14 rolling on a pitch plane 13 of the rack 10 which is provided with straight-sided teeth 12. The teeth may be cut by a hobbing cutter with rack teeth 12 reciprocating parallel to the conical surface of the gear cone and then modified by a shaving operation performed by a cylindrical gearshaving cutter 62, Fig. 5, rotating in mesh with, and on a crossed axis with respect to, the gear cone 60. Gears with straight or spiral teeth may be provided and pairs of gears may be arranged to operate with their axes intersecting or non-intersecting and non-parallel. |
