GB168379A - Edge grinding machine for lenses - Google Patents

Abstract

168,379. Long, E. M., and Standard Optical Co. May 27, 1920. Disc apparatus.-A machine for grinding the edges of elliptical lenses comprises means by which the lens is rotated in contact with a grindstone at such a varying angular velocity that all parts of its periphery shall be completed at practically the same time. A grindstone 10, Fig. 4, supplied with water from a reservoir 5, is mounted on a shaft 11 supported in a frame 1 provided with an inclined guideway 7, on which is bolted a movable section 8. A sliding carriage 16 is reciprocated on guides on the top of the section 8 by means of a piston in a cylinder supplied with fluid from a pendant pump, as described in Specification 151,303. A lens-holder frame 62, pivotally mounted on arms 60 on the carriage 16, is urged towards the grindstone 10 by weighted levers or springs. A shaft 65 journaled in an extension 64 of the frame 62 is driven from a shaft 43 through a flexible shaft 68 and spiral gears 69, 70. The upper end of the shaft 68 is journaled in a yoke 72 pivoted on an eccentric rock-shaft 73 carried by arms 74, Fig. 5, on the extension 64. A handle 75 serves to rotate the eccentric shaft 73 and throw the gears 69, 70 out of mesh. A disc 83, Fig. 6, on the shaft 65 drives at a varying speed a disc 84 on a parallel shaft 82; a link 85 connects the discs 83, 84. Lens-clamping members 77, 78, provided with pads, rotate with spindles 79, 80, which are driven by 2 : 1 reduction gears from the shaft 82. A hand-lever 102, Fig. 8, partially rotates a rock-shaft 97 having cam-surfaces 99, which engage pins 100 on a rock-arm 93 pivoted on a spindle 94. The pins 100 act radially on the shaft 97 and so lock the latter in any position. The end of the arm 93 engages a grooved collar 91, thrust ball bearings 86<1>, and springs 92, a longitudinal movement to the shaft 80 thus clamping a lens between the members 77, 78. A lens pattern 89 on the member 77 bears against an adjustable back-rest 111, Fig. 1, and causes the frame 62 to swing towards and from the grindstone and thus grind a lens, between the members 77, 78, to the required shape. The grindstone is kept true by an adjustable device 114.