Measuring set for determination of the sagittal depth and the average central curvature of gel contact lenses

Claim 1

Apparatus for detecting sagittal depth and average curvature of gel contact lenses comprising a first and second measuring unit, each of which having a fixed support plate, a hollow conductive screw post fixedly secured to said support plate and extending perpendicular thereto, a rotatable lens support comprising a central boss and an integral disc extending radially therefrom, said boss being matingly threaded on said screw post, the boss of said first unit being formed of a frontal face adapted to receive a lens thereon about its peripheral edge, the nut of said second measuring unit being formed of an annular edge of a diameter adapted to seat the lens thereon substantially about the periphery of the corneal part of said lens, a conductive wire insulatingly secured in fixed position coaxially within said screw and extending outwardly of the end thereof by a predetermined distance, said conductive wire extending freely through said boss in opposition to the center of said lens, said lens being movable toward and away from the tip of said wire on rotation of said lens support, and an electronic conductivity indicator having a pair of inputs connected respectively to said conductive screw post and said conductor wire and forming a circuit on engagement of said lens with said wire.

Claim 7

The apparatus according to anyone of claims 1, 2, 3 or 4, wherein the lead of the hollow screw of the first measuring unit is 1 to 2.5 mm per one revolution and the mutual position of the frontal face of the rotatable lens support and the protruding end of the wire conductor is at most 4.5 mm within the limits of one revolution, and the lead of the screw of the second measuring unit is 0.6 to 1.25 mm of the distance of the protruding end of the wire conductor above the plane and the supporting edge is at most 2.7 mm within the limits of one revolution.