Abstract: An apparatus for edging the periphery of an ophthalmic lens to a predetermined outline or edge configuration, is characterized by a pair of grinding wheels, one for rough grinding or shaping the lens and the other for peripherally beveling the edge of the lens, a workholder for supporting and rotating the lens and mechanisms for moving the rotating lens into engagement with the grinding wheels. Manual controls are on the apparatus and automatic control circuitry is in a module remote from but electrically connected with the apparatus, whereby the apparatus may be manually and/or automatically controlled to only shape a lens, to only bevel edge a lens or to both shape and bevel edge a lens.
Abstract: A method of grinding the peripheries of articles such as ophthalmic lenses and the like with a grinding wheel to a predetermined outline or edge configuration, is characterized by the steps of detecting the height of discrete positions on the grinding wheel surface between opposite sides thereof and generating signals having values representative of the height of the positions. The values of the signals are compared, and an indication is generated of the position on the grinding surface whereat the signals represent greatest height. The indication is then used to control movement of the article against the highest position on the grinding surface for being ground. In consequence, the wheel wears evenly, it retains a substantially cylindrical shape, all portions of its grinding surface are effectively used in grinding articles, and formation of a groove in its surface is prevented, whereby the wheel does not require retruing or reshaping and its useful life is significantly increased.
Abstract: An apparatus for edging the periphery of an ophthalmic lens to a predetermined outline or edge configuration, is characterized by a work holder for supporting and rotating a lens while moving an edge of the lens against a grinding surface of a grinding wheel. During grinding the lens is engaged with only a portion of the surface, and to prevent a groove from being formed in the surface a sensor automatically detects the highest point on the surface and controls movement of the work holder to move the lens thereagainst. In consequence, the wheel wears evenly, it retains a substantially cylindrical shape, all portions of its grinding surface are effectively used in grinding lenses, and formation of a groove in its surface is prevented, whereby the wheel does not require retruing or reshaping and its useful life is significantly increased.
Abstract: The digital indicator measures surface deviations from a reference measurement point and employs a probe or plunger positionable against a part that is being measured such as a machine part. The device basically comprises, in addition to the probe or plunger, strain gage means, an amplifier for receiving signals from the strain gage means, a digital volt meter, a digital display, and a momentary setting swtich. A preliminary signal from the strain gages at an initial pressure level is coupled via the amplifier to a differential input of the digital volt meter. The momentary switch nulls the meter to zero for the initial reading with deviations of either polarity being subsequently registered and displayed on the digital display.
Abstract: An apparatus for edging the periphery of an article, such as an ophthalmic lens to a predetermined outline or edge configuration, is characterized by a work holder for supporting and rotating a lens while moving an edge of the lens against a cylindrical grinding wheel. During grinding, the lens is engaged with only a portion of the grinding wheel, and to prevent a groove from being formed in the wheel successive lenses are automatically and periodically engaged with different portions of the wheel. In consequence, the wheel wears evenly, it retains a substantially cylindrical shape, all portions of its grinding surface are effectively used in grinding lenses, and the formation of a groove in its surface is prevented, whereby the wheel does not require retruing or reshaping and its useful life is significantly increased.