GB244849A - Improvements in machines for grinding and polishing lenses - Google Patents

Abstract

244,849. Long, E. M. Sept. 29, 1924. Lenses, grinding and polishing.-A lens is ground or polished by a rotating lap across the surface of which the lens is oscillated in a curved path. On a table 1 is supported a two-part housing 2, a waste receptacle 3, and a post 7 for the lens holder 6. Within the housing is mounted a shaft 22, and secured to the upper end of the shaft 22 is a conical nut 30, which receives a lap 5, and also secures in place a cap 16 covering a flange 17 of the receptacle 3 to deflect dust &c. into the receptacle. The shaft runs in a bearing 23 and in a hub 10', and has loosely mounted thereon a clutch member 31 driven, through gearing 32, 33, by a shaft 19 and having an inner face 34, which is engaged, when the clutch is in gear, by lugs 39 on levers 37<1>. The levers are pivoted at 38 to a clutch section 36 secured to the shaft 22 and are rocked to bring the clutch into and out of gear by a collar 41 slidable on the shaft. The collar is pressed down by springs 55 and is moved by a lever 42 operated, through a shaft 45 and an arm 47 thereon, by a lever 49. The lens holder 6 is engaged and moved by a member 94 held in either of two sockets 100, 101 in a spring-pressed shaft 96 mounted in a section 84 of a bracket 9 and oscillated about its axis by a rack bar 81 engaging a pinion on the shaft. The rack bar is reciprocated by a rod 79 having thereon a collar 78 engaging an eccentrically bored hub 73 of a hand-piece 72 slidably mounted on a spindle 71, which is secured eccentrically to a shaft 65 journaled in the post 7. In order to vary the stroke of the bar 81 a disc 70 is mounted on the shaft 65, and in the disc are a number of recesses 75, any of which may be engaged by a pin 74 on the hub 73, the hub being raised on the spindle 71 and rotated, a spring 77 serving to press the piece 72 down to retain the pin in a recess. The bracket 9 comprises three parts, namely, two members 87, 88 adjustable around the axis of the post 7 and clamped by bolts 90, a part 83 adjustable about a horizontal axis in the member 87, and clamped by one of the bolts 90, and the section 84 which is adjustable vertically on the part 83 by a pinion 103 and a rack 102; by adjustment of the bracket parts, the position and pressure of the lens on the lap may be adjusted.