Blank for use in a lens pattern generator

摘要

A blank having a rectangular shaped body from which a lens pattern is cut to the desired size and shape of a frame lens opening is connected to other identical blanks to form a chain for continuous feeding to a lens pattern generator. The blanks have ball and socket hinge members symmetrically arranged on each edge with a ball hinge member on one edge being opposite a socket hinge member on the other edge. The hinge members are offset with respect to a plane passing through the center of the body between the top and bottom faces of the blank so that the pivot axis of the ball and socket hinge members on one edge is in the plane of the top face and the pivot axis of the ball and socket hinge members on the other edge is in the plane of the bottom face. The blanks are connected together in a like edge-to-like edge fashion and indicia provided to identify the nasal side of the blank alternates from side to side when the blanks are interconnected in a chain. Rack gears embossed in the margins of the bottom face are provided for complementary engagement with drive gears in a lens pattern generator to advance the blank along a travel path in the generator.