| 摘要 |
Method and apparatus for lens thickness adjustment in injection molding of thermoplastic vision-corrective spectacle lenses without manual addition or removal of shims, of inserts or of any other mold part. Thickness adjustment can be made quickly between molding cycles with a simple manual setting and locking step while the lens mold is kept at very hot operating temperatures, yet with minimal risk of burning the operator. A rotatable adjustment head is mounted externally onto the mold's operator side, and manually-driven rotation turns a threaded screw which engages a mechanical assembly which produces an axially perpendicular motion which in turn drives forward or back the settable position of an optically polished insert within the lens mold's cavity. Preferably, this manually-driven rotation turns a worm gear mechanism which rotates a threaded male shaft within a mated threaded female bore axially perpendicular to the parting line. The mated threaded shaft and bore are part of a loadbearing support assembly joined to an optical insert which is one of an opposing pair within a lensmold cavity. The shaft's rotational displacement produces an axial change in the separation distance of these opposing inserts, and thereby a change in lens thickness. Alternatively, a toggle mechanism replaces the worm gear, shaft and bore assembly.
|
