Back to results
US 4,008,031 AGranted
Apparatus for injection molding lenses
OwnerHermann P. Weberinventor
Life of this patent
Estimating the term…
Abstract
Apparatus for injection molding thermoplastic lenses, such as prescription eyeglass lenses, in a single injection molding operation into a finished single vision or multifocal blank which does not require additional molding or polishing. Movable optical inserts (dies) are forced apart by injected polycarbonate, then the inserts are urged together forcing a portion of the injected polycarbonate into a pocket.
Claims9
An apparatus for injecting molding a lens comprising:
- a housing;
- a pair of dies disposed within said housing and a cavity for receiving molten plastic therein;
- said housing including means permitting the relative movement of said dies such that the volume of said cavity may be varied;
- injection molding means communicating with said cavity for injecting plastic into said cavity;
- at least one transfer pocket for receiving plastic from said cavity, said transfer pocket communicating with said cavity;
- and
- compression means coupled to at least one of said dies, for sequentially reducing the volume of said cavity and for applying pressure to said plastic in said cavity after said plastic is injected into said cavity to transfer plastic from said cavity into said transfer pocket;
- whereby molten plastic may be injected into said cavity, and then the volume of said cavity may be decreased forcing molten plastic from said cavity into said transfer pocket.
5 more elements
Dependencies are inferred from the claim text.