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Publication numberUS1711478 A
Publication typeGrant
Publication dateApr 30, 1929
Filing dateMar 18, 1925
Priority dateMar 18, 1925
Publication numberUS 1711478 A, US 1711478A, US-A-1711478, US1711478 A, US1711478A
InventorsJr Cromwell A B Halvorson
Original AssigneeGen Electric
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Light reflector
US 1711478 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

April 3 1929. c. A. B. HALVORSON, JR 11, 78

LIGHT REFLECTOR Filed March 18, 1925 Inventor: Cromwell A. DHalvorson, Jr:

H18 Attorneg.

Patented Apr 1929.

'UNITED STATES CROMWELL A. B. mvoizson, an, or LYNN, .MASSACHUSETTS, assrenon 'ro GEN-y v 1,711,478 PATENT OFFICE.

ERAL ELECTRIC COMPA NY, A CORPORATION OF NEW YORK.

LIGHT nnrmcron.

Application filed- March 18, 1925. Serial No, 16,552.

My invention relates to a light reflector of a type which is especially adapted for use in traffic signal devices. The invention Wlll be readily-understood from the accompanying specification, reference being had to the accompanying drawing in which the figure is a side view of a. section of the reflector taken along an axial planea Referring more in detail to the drawings, it will be seen that the reflector is provided with a rear opening 2 through which a socket for a light bulb may be inserted. The reflector is also provided with a front opening 3 through which the rays that go to make up the beam from the projector pass forward. 7 The rear portion 4 of the reflector immediately around the opening 2 and extending for some distance therefrom is paraboloidal in form. Beyond the paraboloidal region and extending as far as the ridge 5 the section 6 is spherical. The portion 7 of the reflector to the right of the ridge 5 is also .spherical but has a different curvature than the. region 6." Beyond the spherical region 7 the flaring portion 8 of the reflector is paraboloidal or it may be a surface of revolution generated by any one of the conics.

The center of curvature 6 of the spherical region along an axial plane I have indicated at the point 9. The point 10, on the other hand, is the focal point for the paraboloidal regions 4 and 8 and the central point ofthe spherical region. 7. The reflector, therefore, as shown in the drawing conslsts of a surface of revolution formed by revolving a curve about the axis of the reflector, which axis passes through the focal point 10. The

curve as shown. consists of four conics 4, 6, 7, and 8, three of which; to wit: curves 4, 6 and 8, are so positioned with respect to the a focal point that rays originating in the focal point are reflected to the right of the focal plane, while the fourth curve, namely, curve 7, is so positioned with respect to the focal point that the rays originating in the focal point are reflected to the left of the focal plane. The arrows in the figure indicate how the rays that go to make up a beam from a light source located at the point 10 pass out of the reflector. It will be seen that with a reflector of this type a very wide angle of projection is obtained.

It will be understood that whereas I have described my invention in connection with specific construction illustrated I do not wish to be limited to such specific construction inasmuch as various modifications may be made within the scope of my invention and of the claims herein contained.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. A reflector having a reflecting surface in the form of a surface of revolution, said surface being produced by rotating a curve about the axis of the reflector, said curve consisting of four conics, three of said conics facing in one direction with respect to the focal plane of the reflector and the fourth conic facing in the opposite direction with respect to said focal plane, said conics being arranged in the following order from the origin of the surface of'revolution, two facing inonedirection followed by one facing in the tion of a circle, and the fourth a parabola,

both parabolas having a common focal oint, said circle sections having radii of di erent lengths.

2; A reflector having a reflecting surface in the form of a surface of revolution, said surface being produced by rotating a curve about the axis of the reflector,said curve consisting of four conics, three of said conics facing in one direction with respect to the focal plane of the reflector and the fourth conic facing in the opposite direction with respect to said focal plane, said conics being arranged in the following order from the origin of the surfaceof revolution, two facing in one direction followed by one facing in theopposite direction and the latter followed by the last facing in the same direction as the first two, the first curve in order being a parabola, the second and the third, each the section of a circle, and the fourth a parabola, both parabolas having a common focal oint, said circle sections having radii of di erent lengths, the center of curvature of one" of said circular sections being located on said axis and the center of curvature of the other section of a circle falling outside of the said axis.

3.- A reflector comprising focalizing surfaces of revolution generated about an axis, said reflector being provided with a rear opening and with a front opening, said axis passing through the center of said openings, the rear portion of the reflector formed about i said rear opening with its focalizin surface facing toward the front opening an a front portion of the reflector being ormed about I the front opening and located with its focalijz- 5 ing surface facing toward therear opening,

m ing at the same plane, the diameter of the front portion of the'reflector at said plane being greater than the diameter of 'therea'r portion of the reflector at the same the front and rear portions of there ector bending" abruptly to meet each other along said plane and form a .ridge about said reflector along said plane, said reflector having a flaring surface about the front opens ing joining the forward portion of the said -front section of the reflector, and the flaring portion of the reflector facing in the same direction as the rear portion .of'the reflector the rear surface being part'paraboloidal' an lane,

paraboloidal and the front portion next to said plane being spherical. I

4. A focalizing reflector having a reflecting surface in the form of a surface of revolution produced by rotating a curve about an axis, said curve consisting of four conics arranged in the following order from rear to front, a parabola, a circle, a second circle and a parabola, said surface having a rear parabo ic portion, two spherical portions,-one being concentric and the other being eccentric, and a front parabolic portion, said parabola sections'and one of said circle sections having a common focal point and the radii of said circle sections crossing each other, the focal point of said other circle section being located outside of the focal sections. p

In witness whereof, I'have hereunto set my hand this 16th day' of March, 1925.

.CROMWELL A512. HALVORSON, JR.

point of said parabola

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2629046 *Jan 3, 1951Feb 17, 1953Milton LibermanLamp supported reflector unit
US3132812 *Aug 29, 1961May 12, 1964Eastman Kodak CoFlash reflector with improved corner illumination
US4651262 *Dec 27, 1985Mar 17, 1987Valtion Teknillinen TutkimuskeskusLighting device
US4686612 *Oct 25, 1985Aug 11, 1987Optech Inc.Lamp reflector assembly
US4750097 *Nov 25, 1986Jun 7, 1988Optech Inc.Lamp reflector assembly
US5143447 *Aug 5, 1991Sep 1, 1992Bertenshaw David RLamp system having a torroidal light emitting member
US5235499 *Jun 22, 1992Aug 10, 1993Strand Lighting LimitedLamp system having a torroidal light emitting member
US6161946 *Nov 9, 1998Dec 19, 2000Bishop; Christopher B.Light reflector
US7993034 *Sep 22, 2008Aug 9, 2011Cooper Technologies CompanyReflector having inflection point and LED fixture including such reflector
US8100556Jul 31, 2008Jan 24, 2012Cooper Technologies, Inc.Light fixture with an adjustable optical distribution
US8123382May 26, 2009Feb 28, 2012Cooper Technologies CompanyModular extruded heat sink
US8256923Dec 6, 2010Sep 4, 2012Cooper Technologies CompanyHeat management for a light fixture with an adjustable optical distribution
US8272756Dec 20, 2010Sep 25, 2012Cooper Technologies CompanyLED-based lighting system and method
US8491166Sep 22, 2008Jul 23, 2013Cooper Technologies CompanyThermal management for light emitting diode fixture
US8529100Feb 14, 2012Sep 10, 2013Cooper Technologies CompanyModular extruded heat sink
US8567987Jul 19, 2010Oct 29, 2013Cooper Technologies CompanyInterfacing a light emitting diode (LED) module to a heat sink assembly, a light reflector and electrical circuits
US8596837Sep 20, 2011Dec 3, 2013Cooper Technologies CompanySystems, methods, and devices providing a quick-release mechanism for a modular LED light engine
US8696169Jun 20, 2012Apr 15, 2014Cooper Technologies CompanyLight emitting diode lamp source
US8789978Jan 7, 2013Jul 29, 2014Cooper Technologies CompanyLight emitting diode recessed light fixture
Classifications
U.S. Classification362/350
International ClassificationF21V7/04
Cooperative ClassificationF21V7/04
European ClassificationF21V7/04