Patent GB-163950-A (GB)
Title: An improved machine for bevelling the edges of spectacle or other lenses
IPC: B24B9/14
Filed: 1920-09-08
Abstract: 163,950. Druiff, W. J. Sept. 8, 1920. No Patent granted (Sealing fee not paid). Bevelling; lenses, grinding and polishing.-A spectacle or other lens is rotatably carried by a pivoted frame, which is swung automatically at intervals to present opposite sides of the lens to an axially reciprocating grinding-wheel, and is moved under the control of a templet to secure the desired shape of lens. On a table 1 is mounted in bearings 2, 3 a beltdriven shaft 4 carrying a grinding-wheel 6 moved axially by a cam 20, which is rotated through toothed gearing 13, 13a, 15a and worm gearing 7, 9 by the shaft 4 and engages rollers 19 carried by a fork 17 rotatably mounted on the shaft. The lens x is mounted on a carriage having a plate 32a pivoted at 32 to the table and adapted to be swung, to present opposite edges of the lens alternately to the grinding-wheel, by a rod 29 mounted beneath the table and slotted to engage a pin 31 carried by the plate. The rod is pivoted to a link 28, which is pivoted to the table and to a longitudinally slidable rod 26 carrying rollers 25 engaged by a cam 24 carried by a shaft 88 and rotated, through bevel-gearing 21, 21a, by the shaft 10 of the worm-wheel 9. On the plate 32a is mounted a slide 33 provided at its ends with lugs c, d forming bearings for a spindle a, on which is pivotally mounted a frame 38'. This frame carries, in bearings 38<a>, 38<b> thereon, two spindles 40, 41 each carrying a head whereby the lens x is clamped between the spindles. The spindles are rotated in the same direction and at the same speed, through gearing 62, 63, 64, 62<a>, 63<a>, 64<a> and the spindle a, by a shaft 45 having therein universal joints and. driven, through bevel and chain gearing, by the shaft 10. The slide 33 is movable on the plate 32<a> by a screw 34 having a milled head 34a; automatic operation of the slide is brought about by means of a ratchet-wheel 36a on the screw operated by a pawl 38 carried by a spring-pressed arm 37, which is struck at each angular movement of the carriage to the left, Fig. 2, by an adjustable stop 39 carried by a bracket 40. The feed is stopped by an adjustable shroud for the teeth of the ratchet-wheel or by constructing the wheel so that some of the tooth are missing. The spindle 40 may be moved to accommodate lenses of different thicknesses by a micrometer screw 42, and the spindle 41 may be moved by a nut 41<c> mounted in ball bearings 41<d> and engaging a screw-thread 41<b> on the spindle. On the outer end of the spindle 41 is mounted a templet 54<a> having an outline corresponding to the finished shape of the lens and engaging a plate 55 carried by a projection 56 on the slide 33. The plate may be adjustable towards and from the templet to allow of variation of the size of the len@ or to compensate for wear; for this purpose, the plate is mounted on an arm 55a, Fig. 6, pivoted to the slide and pressed by a spring towards a vertical member 57, forming a backing for the arm and carrying a screw 58 for adjusting the arm. The templet is pressed against the plate 55 by a spring 59 connected at one end to the member 57 and at the other end to a rod 60, which is slotted to engage the edge of a hole in a plate 61a pivoted on the spindle a, whereby the plate presses against the templet. In order that the lens may be withdrawn from the grinding-wheel when being swung over to operate on the opposite side, the spindle a drives, through chain gearing, a cam 69 carried by a spindle 68 mounted in the member 57 and having a projection 70 contacting with the back of the plate 55 or its support and adapted to press back the lens carriage at the required moment.