Insert for molding convex surfaces of progressive lenses and retainer therefor

摘要

An insert for molding the convex surface of a progressive lens, the insert having an annular shoulder or flat disposed to the rear of the front edge of the concave surface of the insert. The periphery of the insert includes a first cylindrical surface axially extending rearwardly from the front surface of the insert and a second cylindrical surface of larger diameter axially extending forwardly from the rear surface of the insert. The two cylindrical surfaces are joined by the radially extending shoulder. A retainer for the insert is provided with two axially displaced bores of respective diameters slightly greater than those of the two cylindrical surfaces of the insert. Positioned between the bores is a radially extending annular shoulder or flat.