The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 03, 1998
Filed:
Mar. 20, 1996
Gunter Schonfeld, deceased, late of Wiedelach, DE;
Thomas Schonfeld, executor, Berlin, DE;
Deutsche Spezialglas AG, , DE;
Abstract
When blank-molded optical glass bodies are manufactured according to known methods based on blank-molding technology, the product exhibits rings in the glass and folds as well as an impression that precisely coincides with the contact surface of the parison inside the pressing die before the pressing operation. These defects are not permissible in blank-molded lenses, however, because they cause an undesirable optical effect such as changing the glare value in automobile headlights. Such defects are process-dependent and are caused by the fact that the transfer of the parison to the pressing die and the pressing itself are two separate operations that are performed with different tools. According to the invention, the formation of folds and rings in the glass as well as an impression of the contact surface of the parison are prevented by the fact that the removal and the transfer of the parison to the pressing die and the pressing cycle are performed without interruption with one and the same tool (multi-purpose tool). In a further development of the invention, the pressing operation is performed in two steps to take into account the given thermal inhomogeneities in the formed bodies.