Method and device for remedying the fragility of the edges of a spectacle lens made of rigid material and corresponding spectacle lens
AssigneeEssilor International (Compagnie Generale d'Optique)
InventorFrancis Henky
Life of this patent
Estimating the term…
Abstract
Method and apparatus to eliminate the sharp edge between each of the faces of an ophthalmic lens blank and the peripheral cylindrical surface therebetween. The connecting zone between each face and the cylindrical surface initially includes an edge. A cylindrical deburring tool is mounted on a tool support for pivotal movement orthogonal to the axis of the lens. Rotation of the deburring tool about its axis is prevented. The angle position of the deburring tool is adjustable. A spring urges the mounting to a rest position. A drive displaces the tool support.
Claims14
Method of preparing an ophthalmic lens blank having front and rear faces, one of the faces being concave, and a cylindrical peripheral edge surface disposed between said front and rear faces, a connecting zone connecting each face and said cylindrical peripheral edge surface comprising a ridge, the method comprising the steps of:
- rounding the connecting zone between at least the concave one of said faces and the cylindrical peripheral edge surface to eliminate the ridge and joining the resulting rounded connecting zone substantially tangentially to at least the cylindrical peripheral edge surface.
A machine for preparing an ophthalmic lens blank having front and rear faces, one of said faces being concave, and a cylindrical peripheral edge surface disposed between said front and rear face, a connecting zone connecting each face and the cylindrical peripheral edge surface, said machine comprising a support means for supporting a lens blank for rotation about an axis of rotation, a tool support mounted for movement in a plane passing through the rotation axis, a deburring tool including a working surface having a circular cross section cylindrical surface with an axis and a diameter, said working surface having an axial length greater than the diameter thereof, means mounting the deburring tool on said tool support for pivoting movement about a pivot axis, orthogonal to the rotation axis of said support means, means for preventing rotation of said deburring tool about said working surface axis during operation of the deburring tool, means for adjusting the angular position of said deburring tool about said working surface axis, spring biasing means for urging said deburring tool towards a predetermined rest position, and drive means for displacing the tool support and the pivot axis therewith along a path of movement lying in the plane passing through the rotation axis of support means.
Dependencies are inferred from the claim text.