GB568616A - Improvements in or relating to machines for machining helical spur gears - Google Patents

Abstract

568,616. Gear-cutting. AEPPLI, A. July 14, 1943, No. 11477. Convention date, June 30, 1942. [Class 83 (iii)] In a machine for grinding or otherwise cutting the teeth of helical spur gears, the rolling motion for generating the tooth flanks is given to the grinding disc and the work is moved axially, a rotary motion to generate the helical formation of the teeth being given to the work by a rolling cylinder coaxial therewith and connected to a second rolling cylinder mounted on a perpendicular axis, this cylinder being rotated by a third rolling cylinder coaxial therewith and connected to a rectilinear rolling surface. The machine comprises a pillar 35 carrying vertical guides for the work slide 4 which is reciprocated by means such as a link 40 and driving gear (not shown), and carries the work arbor 6 and a dividing head 16 which is indexed step-by-step. Two grinding discs 25, mounted on opposite sides of the work axis, are angularly adjustable, to suit the work helix, on heads 31 which slide along straight guides 32 on sector-shaped carriages 26 which are oscillated about the work axis A-A by pinions and toothed sectors. During the oscillations, the heads 31 are given a rolling generating motion by steel tapes 29 connecting them to a fixed cylinder 28 mounted on a pin 41 coaxial with the work 13. A cylinder 1 is attached to the work arbor 6 and connected by crossed tapes 7 to a cylinder 2 on a perpendicular axis carried by the slide 4, and a further cylinder 3 on this axis is connected by tapes 9 to a rectilinear member 21. In one construction, the member 21 is mounted stationarily on the pillar 35 so that the vertical reciprocations of the slide 4 will generate the helical shape of the teeth according to the relative diameters of the cylinders 1-3 and the work, and in another construction the member 21 carries a roller which is maintained by a spring 48 in contact with a lever 22 pivoted to the pillar 35 at 23 the other end of the lever being maintained by a spring 49 in contact with a roller 24 on the slide 4. In this way, the angle of helix generated may be varied by altering the pivotal distances p, x without changing the cylinders 1-3, either by displacing the roller 24 or the pivot 23, or by placing the pivot 23 between the slides 4, 21. To enable the diameter of the roller 2 to be varied minutely, the roller may consist of split sleeves mounted on a tapered arbor 17, Fig. 4, and adjusted axially by nuts 19, 20, and the rolling cylinders and tapes may be replaced by toothed pinions and racks. Specification 351,092 is referred to.