US1711480A

US1711480A - Light-projecting device

Info

Publication number: US1711480A
Application number: US73010A
Authority: US
Inventors: Jr Cromwell A B Halvorson
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1925-03-18
Filing date: 1925-12-03
Publication date: 1929-04-30
Anticipated expiration: 1946-04-30

Description

9 3 1929iv c. A.B. HALVORSON, JR 1,711,480

LIGHT PROJECTING DEVICE 4 Sheets-Sheet 1 Original Filed March 18, 1925 Inventor: I Cromwei Afifialvor fiomdh 9 His Attorney April 3Q 12929 c. A. B. HALVoRsoN. JR

LIGHT PROJEC'TING DEVICE Original Filed March 18, 1925 4 Sheets-Sheet F'Lg. 2.

v Inventor". Cromweii Afihalvorsomdr j. A g L 9 n P a m K a m H Uu b April 36, 1929.

wALvomaoN, JR

LIGHT PROTECTING DEVICE Driginal Filed MarchlB, 1925 4 Sheets-Sheet 3 A ril 30, 1929 C. A. B. HALVORSON, JR LIGHT PROJEG-TING DEVICE Original Filed Maf o h- 18, 1925 4 Sheets-Sheet 4 Invento r:

Crornwell Afihalvorsomdr HLS Attomego Patented Apr. 30, 1929.

y UNITED. STATES PATENT OFFICE.

.OROMWELL A. B. HALVORSON, JR., OF LYNN, MASSACHUSETTS, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK,

LIGHT-PROJECTING DEVICE.

Original application filed March 18, 1925, Serial camber 3,1925.

My invention relates to a light projecting device. More in particular, it relates to a device which is especially adapted for use as a traflic signal.

Among the objects of my invention are to provide an improved projector in which a hood and a lens are used'and which may be removed as a unit, and to provide-a constructionin which the hood, the lens, the reflector and the'light source maybe removed as a unit from the projector.

To accomplish the foregoing my invention comprises means hereinafter more fully set forth and claimed, reference being had to theaccompanying drawings in which Fig. 1

shows a pendant type of traffic signal in elevation; Fig. 2 shows a second form of the traflic signal in perspective with the hood element removed; Fig. 3'shows one ofthe hood elements in perspective; Fig. 4 shows in perspective one of theprojector elements comprising the hood element and the reflector element assembled; Fig. 5 1s a section through the projector element of Fig.

4; Fig. 6 shows a'section of the form of housing, a number of which are shownassembled in Fi 1; Fig. 7 shows a standard in section whic is adapted to serve as a support for the form of signal shown in Fig. 1

when it is desired to place the signal upon an upright. Fig. 8 is a drawing on a larger scale than the drawing of Fig. 5 of the reflector element of the projector showing the path of the rays. in section and also shows the focal polnts of the dilferent forms'of surfaces WlllCll go to make up the reflector.

Referring more in detail to the drawings,

it will be seen that the reflector, Fig. '8, is 40 provided witha rear opening .2 through which a socket for a light bulb may be 111-.- serted. The reflector is also. provided with a front opening 3 through which ."the raysthat go to make up the beam from the projectoi' pass-forward. The-rear portion 4 of the reflector immediately around the opening 2 and extending for some distance. there-. from is paraboloidalin form. Beyond the.

paraboloidal region and "extending as far as the rid 5 the section 6 is spherical. The portion 0 the reflector 7 to the right of the ridge 5 is also spherical but has a different.

This drawing is shown No. 16,552.. mvi-ded and this application filed De- 1 Serial 'No. 73,010.

a surface of revolution generated by any one of the conics.

The center of curvature of the spherical region 6 I have indicated at the point 9. The polnt 10,.on the other hand, is the focal point for the paraboloidal re ions 4 and 8 and the-central point of the sp eric'al region The reflector, therefore, as shown in. the drawing consists of a surface ofrevolution 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, namely, curves 4, 6 and 8, are so positioned with respect to the 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 respectto the focal point that the rays originating in the focal point are reflected tf) the left of the focal plane. It will be seen, therefore, that these conics are all focalizing curves-with their concave sides facing toward the focal point, but curves 4, 6 and 8 are facing toward the left of the focal plane, while curve 7 is facing toward the right of the focal plane, The arrows in Fig. 8 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 the casing ,is provided with a flange 11 and with a depression in the form of a forwardly sloping zone 12, (Fig. 5), from the forward end of which zone the collar 13 extends. The reflector is mounted with. the outer spherical section? resting against zone 12 of cthe front element. The reflector is clamped in position by means of a number of spring strips 14, the forward ends ofwhich are secured to the front plate by means of screws 15. A rear plate 16 serves as a rear support for the reflector and is fastened to the springs 14: by means of screws 17. This rear support seen that with a reflector of thistype a very is provided with a rearwardly projecting collar' 18 through which the socket'19 which supports the light source projects. -The center of this light source, it will be understood, is placed to coincide with the focal point 10, Fig. 8, of the reflector. It will be seen that the front plate is provided with a series of screw holes in order that. the projector element may be properly secured to the casing of the unit, as for example, by means of screws 11, Fig. 2.

The visor 21 otthe projector is made with an annular portion 21 which serves to hold the lens 22. This lens is locked in position between a felt or rubber cushion on one side and the ring-like spring 23. It will be seen that to the rear ofthe annular portion 21 there is provided a flange 24 which is split on the underside, Figs. 3 and 5, and by means of a screw or bolt 25 this flange may be tightly clamped to the collar 13 of the front plate.

With this construction if it is desired to remove the electric lamp from within the reflector it is only necessary to loosen the bolt 25 and remove the hood element from the collar 13. The hand may then be inserted through the front opening 3 of the reflector to reach the lamp. In case it is desired to reach-the socket 19 the projector unit may be removed asa whole by removing the screws 11% It will be understood that the cord 26 inside the housing may be made of any suitable length in order that the projector element may be withdrawn without difiiculty. All of the cables 26 within the unit may be connected to a common terminal element towhich the.

leads from the source of power fnay be connected. I

The type of easing shown in Fig. 1 is formed of one or more sections such as the section shown in Fig. 6. These sections may be placed one on top of. another and bolted together each section to the next adjoining section for example. For this purpose the lugs 27, Fig. 6, are provided with suitable holes 28 through which the bolts or screws pass. minal piece 29 is securedto the lowermost section of the casing.

When the casing is to be mounted on to of a standard such as that shown in Fig. the bottom piece 29 of Fig. -1 is omitted and the casing is set on top, of the upright, Fig. 7, and screwed thereto. For this purpose the lugs 30 with the proper holes for screws or bolts are provided.

The unit in Fig. 1 is provided with a cap piece 31 which is bolted to the topmost section of the casing in a similar manner. This element 31 is provided with an opening on top which is closed by the cap piece 32 which latter is suitably'screwed or bolted to the section 31. The cross piece 33 is in turn secured to the piece 32 and serves as a support for the wholeunit. Suitable openings are provided through this piece 33-through which In a similar manner the bottom ter-' min-ass the cables or conductors pass into the interior of the un1t, the

members

32 and 31 bemg,of course, provided with a central opening.

In this trailic signal the visor 21 extends "is to prevent exterior sources of light, such as the sun or moon or street llghting units,

from striking the lens 22 and making it appear that the signal is in operation. Heretofore, such exterior sources of light have produced this eii ect and caused error and confusion in consequence.

While in Fig. 2 the housing has been shown as one continuous section this housing may be constructed with a number of elements, such as shown in Fig. 6, turned at right angles to the position shown in Fig.6. With such an arrangement, however, some of the openings 34 through which the projector of Fig. 4 is inserted in place may be omitted, for example, the openings which would other- .wise appear on the underside of the casing in the form of Fig. 2. Although the casing in Fig. 6 is shown with a straight edge, the construction may be changed to be square to conform with the form indicated in Fig. 2.

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.

W hat I claim as new and deslre to secure by Letters Patentof the United States, is

1. In a light projector, a casing, an opening in said casing, said casing being provided with a protuberance to one side thereof sur: rounding said opening, a-visor over said opening, means clamping said visor to said protuberance, *a lens over the end of said protuberance, means retaining said lens in place, a substantially globular hollow element in .said casing, means holding said element mounted with its axis parallel to the axis of the protuberance and with a portion of one hemisphere of the element seated'in said protuberance, the other hemisphere of said element being substantially a beam-forming reflector.

2. In a light projector, a casing, an opening in said casing, said casing being provided with a protuberance extending to one side cylindrical portion of said protuberance, of the protuberance and with a portion of the means in said cylindrical band for retaining other hemisphere thereof-seated in said prosaid lens in place, a hollow globular member tuberance.

v 10 within saidcasing, one hemisphere thereof In witness whereof, I have hereunto set being a beam-forming reflector means holdmy hand vthis first dayof December, 1925.

ing said member mounted in said casing with the axis of the member parallel -to the axis CROMWELL A. B. HALVORSQN, Jr.