US3609340A
Expired / Lapsed
US
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Improvements in lighting units
Assignee: VAGBELLYSNING AB
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Filing: 1969-04-17
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Granted: 1971-09-28
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Expires: 1989-04-17
Abstract
Abstract A lighting unit consists of an elliptic rotational reflector having the light source positioned in one focal point, and a convex reflector facing the elliptic rotational reflector and serving for polydirectionally radiating the light rays which are emitted by the light source and pass through the other focal point of the elliptic rotational reflector. The convex reflector has at least one cup-shaped inwardly bulging recess which reflects the light rays impinging thereon at least essentially parallel.
Inventors
- 👤 Lars Bertil Habro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:58
CPC Classifications
F; F21; F21V; F21V7/00; F21V7/0008; F21V7/04; F21V7/09
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
131 words
A lighting unit of the type comprising an elliptic rotational reflector having a light source positioned in one focal point thereof; and a convex reflector facing the elliptic rotational reflector and preferably formed as a segment of a sphere for polydirectionally radiating the light rays which are emitted by the light source and which pass through the other focal point of the elliptic rotational reflector, said convex reflector having at least one cup-shaped inwardly bulging recess which reflects the light rays impinging thereon at least essentially parallel, said cup-shaped inwardly bulging recess being defined by a generated curve y f(x) the focus of which is situated in the other focal point (F2) of the elliptic rotational reflector, said curve having been caused to rotate about its axis (O-X) through the focus.
Claim 2
Dependent Claim
131 words
A lighting unit of the type comprising an elliptic rotational reflector having a light source positioned in one focal point thereof; and a convex reflector facing the elliptic rotational reflector and preferably formed as a segment of a sphere for polydirectionally radiating the light rays which are emitted by the light source and which pass through the other focal point of the elliptic rotational reflector, said convex reflector having at least one cup-shaped inwardly bulging recess which reflects the light rays impinging thereon at least essentially parallel, said cup-shaped inwardly bulging recess being defined by a generated curve y f(x) the focus of which is situated in the other focal point (F2) of the elliptic rotational reflector, said curve having been caused to rotate about its axis (O-X) through the focus.
Claim 3
Dependent Claim
21 words
A lighting unit as claimed in claim 1, wherein the convex reflector has two substantially diametrically opposed, cup-shaped, inwardly bulging recesses.
Claim 4
Dependent Claim
28 words
A lighting unit is claimed in claim 1, wherein the axis (O-X) of the curve y f(x) through the focus is inclined in relation to the horizontal plane.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |