Method of manufacturing a mould for producing a lamp lens element
US4198182A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1978 |
| Grant date | Apr 15, 1980 |
| Priority date | — |
| Expiry date | Apr 19, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T409/303808
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A mould for producing a lamp lens element comprises a mould plate having a plurality of recesses in one face thereof. Each recess is adapted to produce a projection on one face of the lens element produced from the mould, and is shaped so as to define in the projection a lens integral with and overlying a prism. In one embodiment, each recess has a concave part-spherical surface portion whose axis is inclined to the perpendicular to the general plane of the said one face of the mould plate. Alternatively, each recess is in the form of an elongate groove having a part-cylindrical mid-region whose axis is inclined relative to the general plane of the said one face of the mould plate. In the latter case, the groove also has part-spherical end regions whose axes are each either perpendicular to the said general plane or inclined at an acute angle to the perpendicular to the general plane. In a further embodiment, each recess is in the form of an elongate groove wich is concavely curved in a longitudinal plane thereof and shaped so that the said lens and the said prism are each of part-annular form. In all of the above cases, adjacent recesses overlap and are arranged in a plurality of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.