US1361852A - Illuminating apparatus - Google Patents

Description

E. A. HAWTHORNE.

ILLUMINATING APPARATUS. Y

APPLICATION FILED SEPT. 14, 1917.

1,361,852, Patented Dec. 14,1920.

2 SHEETSSHEET In-veni ova: Eiisworih fl. Hawiho rue 5y W lgkza E. A. HAWTHORNE ILLUMINATING APPARATUS.

APPLICAIION FILED SEPTX14. 1917.

Patented Dec. 14, 192( 5 2 SHEETS-SHEET 2.

. Inventor: E'Zisworifhfl Hawihorne,

50 candescent bulb disposed in axial aline- UNITED STATES PATENT OFFICE.

ELLS WORTH A. HAWTHORNE, F BRIDGEPORT, CONNECTICUT i ILLUMINATING APPARATUS.

To all whom it may concern: Be it known that I, ELLSWORTH A. HAW- THORNE, a citizen of the United States, and

a resident of Bridgeport, in the county'of Fairfield and State of Connecticut, have invented an Improvement in Illuminating Apparatus,-of which the following description, in connection with the accompanying draw-. ings, is a specification, like characters on the drawings representing like parts.

This invention relates to illuminating apparatus and is more especially though not exclusively concerned with a light concentrating and pro ecting lamp or searchlight .of the class in which provision is made for preventing objectionable glare. My invention will be best understood by reference to the following description when taken in connection with the accompanying drawings of three specific embodiments thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings, Figure l is a central vertical longitudinal section of an illuminating Referring to Figs. 1, 2 and 3 andto the embodiment of my invention which 'l have selected for exemplification therein, I have shown an illuminating apparatus comprising a suitable .casing 7 having alight transmitting opening 8, with a suitable closure therefor such as a glazing 9,,and having an interior reflecting surface conveniently in the form of a separate reflector 10 which is preferably a paraboloidof comparatively long focus to project forward in a substantially parallel beam rays of light falling thereon from a substantially focally disposed light source 11, herein in the form of an inment with the reflector This bulb may be and is herein mounted'in and carried by an adjustable socket member 12 to permit the same to be moved in and out axially with relation to the reflector. I t will be under- Specification of Letters Patent. Patented Dec, 14, 1920. Application filed September 14, 1917. Serial No. 191,346. V

stood that if the socket 12 be adjusted so that the light source 11 is at the focal point of the parabola, the reflected rays will be projected forward in a parallel beam and the lamp will function as a true spotlight, but if, on-the other hand, the light source be. moved out of focus, a divergent coneof reflected rays will be produced.

In order to permit the use of a long-,focus reflector without unduly increasing the size of the lamp, the light transmitting opening 8 is placed at some distance from the reflector 10 and a secondary reflector 13 in the form of a spherical zone may be provided, the center of this zone being preferably in the axis of the parabola. In the present example the two reflectors l0 and 13 are connected by a frusto-conical portion 14 which may also be a reflecting surface. If the paraboloid were extended to the position of the secondary reflector 13 the rays would fall thereon at such an angle that they would be ofcomparatively little value. 'The rays which would otherwise fall on such extended portion of the paraboloid herein fall on the spherical secondary reflector 13 which returns such rays to the light source andto the primary reflector 10 and the latter then projects them forward through the light transmitting opening.

To prevent the light emanating from the lamp having an objectional glare, I have hereinshown light interceptingmeans in the form of a hollow cylinder or tube 15, preferably disposed substantially co-axially with relation to the reflectors and preferably mounted on the glazing 9. In the present example I have shown the light intercepting means as secured to the glazing by a screw l6,and a cooperating nut 17 The cylindrical light intercepting means extends inwardly and surrounds the bulb 11 but is cut away at one side, as at'18, to provide a seg mental extension 19 laterally overlying the light source at one side thereof and preferably extending into close proximity to. the reflector 10. H v

The truly cylindrical portion of the light intercepting means 15 outwardly beyondthe cut away portion 18 is preferably so proportioned as to intercept all the direct rays of light from the light source 11 which would otherwise pass through the light transmitting opening 8. Thus the light emanating from the lamp consists splely of reflected rays and thefintense and concen- 125, formed on thetube 21 .nous or reticulated.

trated direct rays are eliminated, thus obviating much of the glare. The seg .ental portion 19 overlies the light source at one side thereof and cuts oil a portion 01 the re flector from its rays. A portion of the beam from the light is thus eliminated and only the rays which extend in a certain direction are utilized. Consequently it is possible to provide a beam of light which will not shine above a certain level and which therefore when used on a vehicle f ill not be projected into the eyes of pedest lens or drivers of other vehicles.

To permit the light source to be screened effectively at one side thereof and the same time provide for such variations in the distance between the glazing and the reflector as may occur in different lamps, I may make the light intercepting means extensible and in the present example it in the form of two telescopically arranged tubes 20 and 21. As a means for securing those two tubes in the desired position of adjustment 1 have herein provided a clamping screw 22 and nut. 23, the screw passing through a slot 2 in the tube 9.0 and the nut 23 being preferably located onthe inside of the latter. An inwardly projecting lug and passing through the slot 24, serves a means to prevent the nut 23 from turning as well to limit the movement of the tube 20.

In practice it is -tound that when a light intercepting screen or" this general type surrounds or incloses a portion of the'light source, so much of the heat is confined by the shield as to have a tendency to overheat the bulb, thus shortening its life, as well as to reduce a discoloration of the reflector 10. i s a means for permitting the escape of such heat without materially impairing the light intercepting value of the screen, some or all of the latter may be foramiin the form shown in Figs. 1, 2 and 3, as well as in the form shown in Figs. 5 and {3, a. portion only of the screen is foraminous, while in the form shown in' Fig. 4; the entire screen is foraminous. that the tube 20 is foran'iinous, while the tube 21 is not. In this "formthe screen is preferably made of closely woven wire netting which is found to give lent results. in the form illustratedin Fig. l l have shown a screen 26 also formed of similar wire netting.

In the form illustrated in Figs. 5 and G l have shogvn light intercepting means similar in most respects to that illustrated in Figs. 1, 2 and 3, except that the adjustable portion is in the form of a. segi'i'iental plate 27 provided with a multiplicity of perforations to permit the escape of the heat. interposed between the end of the tube and the glazing llis a somewhat yieldin Figs. 1 and it should be observed assist insustainihg the weight of the light intercepting means, thus permitting the use of a. thinner glazing than would otherwise be possible.

Regardless of the use of light intercepting means for reducing objectionable glare, there is sometimes a point of view where gl ring rays will affect the eyes oi an observer looking toward the lamp, and under these circrnnstances, the eye is attracted to and dazzled by that portion of the light concentrating means from which the glare emanates. its a means to attract the observers eye away from the dazzling light rays, 1 have found that by making the washer a dark color, preferably though not necessarily black, it presents a dark spot in the midst of the beam and attracts the eye away from-the dazzling rays. ln practice it has been "found that the provision of the black spot as shown in Fig. 2 has a strong tendency to rest the eye and reduce the harmful effect of the glaring rays.

While I have herein shown and described three forms or embodiments of my invention for illustrative purposes and have disclosed and discusses in detail the constructionsand arrangements incidental to these specific applications thereof, it is to be understood that the invention is limited neither to the mere details or relative arrangement of parts nor to the specific embodiments herein shown, but that extensive deviations from the illustrative forms or embodiments of the invention may be made without departing rom the principles thereof.

Having described these embodiments of my invention, what I claim and desire by Letters Patent to secure is 1. in an illuminating apparatus, the combination of a light source, extensible lightintereepting means associated therewith, including two relatively adjustable members, and clamping means including a screw and nut to secure saidmembers in the desired position of adjustment, and means engaging one-side of said nut to hold the same against turning movement.

2. in an illuminating apparatus, the combination of a light source, extensible lightintercepting means associated therewith, including two relatively adjustable members, and clamping means including a-screw and nut to secure said members in the desired.

position of adjustment, and means to limit relative movement of said-members and to prevent said nut from turning.

3. In an illuminating apparatus, the combination of alight source, extensible lightintercepting means associated therewith, including two relatively adjustable members, and clamping means including a screw and nut to secure said members in the desired position of adjustment, one of said members 10 being provided with a slot and the other with a lug projecting into said slot to limit In testimony whereof, I have signed my 15 name to this specification.v

ELLSWORTH A: HAWTHORNE.

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