Society of Glass Technology · [Sheffield] · leaf 734
cam, 67, to its starting position and alsoreleases the lever, 77, from the pin, 76. A new lens may thenbe substituted for the finished lens and the operations repeated. H. G. C. 429. Grinding Bifocal Lenses. M. Bentzon, Neurilly-sur-Seine, Paris (Brit. Pat., No. 172367, August 7th, 1920).—A… … Fig. 227. planes. The lens-holder is carried by a spindle, /, journalled ina vertically adjustable bracket, h, which is mounted on a pillar, d ;the spindle is rotated by a pulley, k. The arms, o, are pivoted atp to pillars, r, mounted on a head, b, and the angular setting ofthe grinding-wheels is…
Glass
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