GB364007A - Improvements in the manufacture of means for producing a straight line motion of lenses in kinematograph apparatus or of other objects - Google Patents

Abstract

364,007. Milling- machines. JOHN, W. E.. National Bank Buildings, Simmonds Street, Johannesburg, South Africa. Aug. 27, 1930, Nos. 25511/30 and 14747/31. [Class 83 (iii).] In a process for forming internal driving faces 34 of the teeth of a pocketed driving wheel 2 forming part of apparatus such as that described in Specification 319,302, [Class 97 (i), Optical systems &c.], in which a series of loose cylindrical bodies such as lens carriers is circulated through a closed path comprising part of the driving wheel 2, a rectilinear and preferably diametral guide 21, and curved transition guides represented by two arcs such as 14, the driving wheel is first provided with pockets 3 of the same diameter d as the loose bodies and the driving faces 34 are then shaped by a milling cutter 9 which is constrained to move along the transition arc 14 while the driving wheel is simultaneously rotated through an arc equal to that through which it would rotate while one of the loose bodies traverses the guide in contact with the driving face. The pockets 3 are first formed by boring holes in a circular blank and then removing the central part of the disc. The blank is then secured to a table 7 rotating on a spindle 8. The tool 9, which is of the diameter d, is driven by an electric motor 10 through a flexible shaft 11 and is mounted on an arm 12 pivoted on a pin 13 so that the cutter may move along the arc 14 of the transition guide. The cutter is axially movable on the arm 12 so that it may be positioned in successive holes 3. An arm 16 integral with and of the same length as the arm 12 carries a pivot pin 17 spaced from the cutter axis by the distance d and connected by a link 18 also of length d with a pivot 19 on a slide 20 which moves in the diametral guides 21. The table is rotated through the circular pitch angle A by means of a worm 24 on a shaft 22 operated by a hand-wheel 23 while the slide 20 is simultaneously moved in unison through the distance d by means of worm gearing 25, shaft 31 and rack and pinion mechanism 27, 28. The feed of the rack 28 corresponds to one revolution of the pinion 27 which is coupled to its shaft by a pin 29 so that the slide 20 may be returned at the end of an operation by disengaging the coupling pin. The feed of the table through the angle A is determined by a pin 33 engaging a series of notches 32. At the end of the operation the cutter is in the position shown in Fig. 2. In some cases, the arms 12, 16 may be separately formed and may be connected together by a link such as 18. The first Provisional Specification also refers to Specifications 290,372 and 334,033, [both in Class 97 (i), Optical systems &c.].