US436677A - thoene - Google Patents

Description

(No Model.) 4 SheetsSheet 1.

J. THORNE & E. B. BURR.

ELECTRICAL HEAD LIGHT.

No. 436,677. Patented Sept. 16, 1890.

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(No Model.)

4 Sheets-Sheet 2. J. THORNE & E. B. BURR.

ELECTRICAL HEAD LIGHT.

No. 436,677. Patented Sept. 16, 1890.

M M j THE NDRmS PETERS co., wum-umu, wasumcn'on, o. c.

(No Model.) I 4 Sheets-Sheet 3. J. THORNE & E. B. BURR.

ELECTRICAL HEAD LIGHT.

No. 436,677. Patented Sept. 16, 1890..

(No Model.) 4 Sheets-Sheet 4. J. THORNE & E. B .BURR.

ELECTRICAL HEAD LIGHT.

No. 436,677. Patented Sept. 16, 1890.

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UNITED STATES PATENT OFFICE.

JAMES Tl-IORNE AND EBENEZER BANTON BURR, OF LONDON, ENGLAND;

SAID BURR ASSIGNOR TO SAID THORNE.

ELECTRICAL HEAD-LIGHT.

SPECIFICATION forming part of Letters Patent No. 436,677, dated September 16, 1890.

Application filed July 2, 1888. Serial No. 278,744.. (No model.) Patented in England February 12, 1887, No. 2,262, and May 13, 1887, No. 7,046; in Belgium April 30, 1888, No. 81,377, and in France June 8,1888,No.189,824.

invented new and useful Improvements in Signal and other Lamps, (for which we have obtained patents in Great Britain, No. 2,262,

' dated February 12, 1887, and No. 7,0i6, dated May 13,1887; in France, No. 189,824, dated June 8, 1888, and in Belgium, No. 81,377, dated April 30, 1888,) of which the following is a specification, reference being had to the accompanying drawings.

The main object of the present invention is to provide an electric head-lamp, taillamp, side-lamp, or other signal-lamp for railway purposes, which will be complete in itself, having no external wires or connections. The present improvements are, however, applicable to mast-head lamps or other signallamps for ships, to lamps for omnibuses, tramway-cars, cabs, velocipedes, or other vehicles, and also to lamps for telegraphing by means of flashing-signals and for mining or other purposes.

In our improved lamp we employ a lens, of which the interior surface is plane and the exterior surface is so curved in one sweep as to give a parallel or nearly parallel beam from a point. The curvature of the exterior surface of the lens should for this purpose be parabolic or approximately parabolic, or elliptic or approximately elliptic. \Ve sometimes em ploy a reflector of corresponding form and so arrange the said lens and reflector relatively to each other and to the light that their foci correspond with each other or lie in the axial line common to both lens and reflector, and the rays of light concentrated by the reflector will pass through the lens. By reason of the peculiar formation and arrangement of the lens and reflector we are enabled to place the light and reflector nearer the lens than heretofore, and thus economize space in the lamp. Moreover, in a lamp provided with our improved lens and reflector, instead of the shape of the lighter flame of the lamp being visible through the lens, as in lamps heretofore constructed, the lens presents the appearance of an illumined disk, the light having substantially the same brilliancy over the entire area of the lens, and the lamp throws out a beam of intense light, which can be seen at: a great distance from the lamp. Vi e thus obtain much better results than heretofore with respect to the intensity of the beam projected from the lamp.

We combine with alantern or lamp-casing in the manner herein described an electric incandescent lamp, an electric battery or accumulator, and a lens of the kind herein mentioned, with or without a reflector, all arranged in the said lantern or casing, so that the apparatus can be readily inserted in or removed from its place on a vehicle or other obj eet without the necessity for connecting or disconnecting any wires. Moreover, as there is no need for ventilation, the said lantern orlampcasing can be made without a chimney or ventilator and can be closed (hermetically, if desired) so as to exclude dust. We arrange the said reflector and lens relatively to each other in the manner above describedthat is to say, so that their foci correspond with each other, being situated in the axial line common to both lens and reflector. By this arrangement of the lens and reflector we are enabled to place the light and the reflector much nearer the lens than heretofore, and thus leave space within the lantern or casing .forthe electric battery without the necessity for increasing the size of the lantern or casing as compared with those ordinarily used for similar purposes. Moreover, we obtain very good results in respect of the intensity of the light passed through the lens.

In the accompanying drawings, Figure 1 is a vertical longitudinal central section ofone form of our improved apparatus. Fig. 2is a transverse section on thelineacx, Fig. 1. Fig. 3 is a vertical transverse central section of another form or modification of our said apparatus; and Fig. 4 is a vertical longitudinal sect-ion on the line 00 ac, Fig. 3.

Like letters indicate corresponding parts throughout the drawings.

a is the lantern or lamp-casing.

bis the 1ens,which is secured therein in any well-known or suitable manner.

c isa parabolic reflector,which is made with a socket 0', adapted to fit upon a bracket d, formed on or attached to a sliding plate (I.

e is the battery, which is placed upon and, if necessary, attached to the said sliding plate.

fis an electric incandescent lamp of any suitable description, which is suspended from wires passed through a block or piece of insulating material inserted in a tube or socket c fixed in the reflector c, the said block or piece being secured by means of a set-screw 0 The plate cl is fitted between guides a, formed on or attached to the casing a, so that the said plate, with thebattery, the lamp, and the reflector, can be very readily inserted in and removed from the said casing.

To provide for tightly closing the battery and at the same time firmly securing it in the casing and preventing its withdrawal except by an authorized person, we employ a screw g, which is passed through a tapped hole in a socket g, secured to the casing a. The lower end of this screw bears against the lid 8 of the battery and holds the same down, so that the battery is kept tightly closed, a sheet or washer of india-rubber or other elastic material being preferably placed between the lid and body of the said battery to insure tightness of the joint. The upper end of the screw g is made square or of other suitable shape, so that a key maybe fitted thereon to permit the turning of the said screw in either direction. The said key is so made that it will fit into the hole or cavity g in the socket g,

' which hole or cavity may be of any desired shape.

WVhen a primary battery is employed, we

- prefer to use that described in the specification of former Letters Patent of Great Britain, dated September 2, A. D. 1882, No. 4,198. NVe may, however, use any other suitable primary battery, or we may use a secondary battery or accumulator.

h is a switch. for completing or interrupting the electric circuit for the purpose of putting the apparatus into or out of action when desired.

We sometimes arrange in combination with this switch a clock-work device for in dicating the length of time during which the lamp has been alight, so that the state of the battery may be readily ascertained at any time. This device is so connected with the switch that when the light is turned off the movement of the clock-work will be arrested; or we use an indicator which may be adjusted by hand for the purpose above specified.

Instead of making the lens of the ordinary spherical form, we prefer to make it in the form of a paraboloid-for example, as shown in the drawings. WVe sometimes, however, make it elliptic or approximately elliptic. Whatever may be the shape of the reflector and lens used, it is advantageous to so adjust the reflector relatively to the lens that their foci will correspond or lie in a common axial line, as above described.

In some instances we dispense with the reflector shown in Figs. 1 and 2 and provide a tube, which is inserted and secured in the aperture in the front of the lantern or lamp-casin g, and in the outer end of which a parabolic lens is fixed. This tube is sometimes made to serve as a reflector, in which case we prefer to make it in the form of a truncated cone or of a truncated paraboloid.

The lamp or apparatus shown in Figs. 1 and 2 will serve very efficiently as a head-lamp or tail-lamp for use on a railway-carriage or locomotive.

Thelamp shown in Figs. 3 and 4 is designed as aside-lamp for arailway-carriage. It has two parabolic lenses 1) and a double reflector that is to say, two parabolic reflectors c, portions of which are cut off through a plane perpendicular to their axes and which are united at c the electric incandescent lamp f being placed in the center, as shown.

When used for railway purposes, our improved lamp aflords, among others, the following advantages,viz: There are no external wires or connections. Thereforethe lampcan be readily transferred from one vehicle to another, and no disconnection of wires is necessary when slipping a carriage. There is no need of ventilation. Therefore the casing can be made without a chimney or ventilator, and can be tightly closed so as to exclude dust. No trimming is required, as in oil-lamps, and there is no smoke, grease, or soot to dim the lens and obscure the light. The light cannot be effected or extinguished, as in oil-lamps, by air currents or eddies produced by the motion of the train or otherwise. There-is no risk of fire in case of breakage of the lamp in a collision or other accident. The lamp can be easily handled, and the battery can be very readily withdrawn, recharged, and replaced.

\Ve sometimes provide interchangeable slides of green orothercoloredglass-as shown, for example, at z in Fig. lwhich can be very readily inserted in and withdrawn from the lantern or lamp-casing for the purpose of changing or determining the color of the light.

For railway purposes our lamp has the further advantage that these slides can be changed without liability to extinctionof the light when the door of the casing is opened. The necessity for any mechanical devices for changing them without opening the said casing is thus obviated.

We do not confine ourselves, save in respect of lens and reflector, to any special form or construction of the parts of our improved lamp, as these will depend to a great extent upon the purpose for which the lamp is required, and can be considerably modified Without departing from the nature of our said invention.

It is evident that our improved apparatus may be adapted for telegraphingby means of reflector being in the same axial line, and an electric lamp, a battery, and connections, all inclosed in the casing, substantially as shown and described.

2. The herein-described lamp or lantern, consisting of the closed casing a, the lens I), having a plane interior surface and an approximatelyparabolic external surface, the parabolic reflector 0, having its focus in the same axial line with the focus of thelens, the battery 6, incandescent lamp f, and batteryconnections, all inclosed in the casing a, and the switch h on the outside of said casing, substantially as shown and described.

In testimony whereof we have hereunto set our hands and aflixed our seals this 18th day 0 of June, 1888.

JAMES THORNE. [n 5.] EBENEZER BAN'lON BURR. in s] Witnesses:

RoBT. JNo. DANTER, W. J. HAMMOND.

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