US1563509A - Method and means for locating lamps - Google Patents

Description

Dec. 1, 19325- D. J. M CARTHY METHOD AND MEANS FOR LOCATING LAMPS Filed April 28, 1921 Patented Dec. 1, 1925. H

ea @FFICE DANIEL J. MCCARTHY, OF ELGIN. ILLINOIS. ASSIGNOR TO CHICAGO RAILWAY SIGNAL AND SUPPLY COMFANY, A CORPORATION OF ILLINOIS.

METHOD AND MEANS FOR LOCATING LAMPS.

Application filed. April 253, 1921. Serial No. 465,143.

To all whom it may concern:

Be it known that I, DANIEL J. NICGARTHY, a citizen of the United States, residing at Elgin, in the county of Kane and State of Illinois, have invented certain new and useful Improvements in Methods and Means for Locating Lamps, of which the following is a specification.

This invention relates to methods and means for locating lamps.

It will be explained as applied to a double lens signal lamp such as may be used in railway work.

In many fields, such for example as railway signalling, electric signal lamps often must be located in relatively inaccessible positions such as the tops of poles. switches. signal towers, etc. The lamps burn out and otherwise become defective and must be replaced.

Not only is it important that the original lamp be properly positioned to give the desired results but replacements must give the same results. However the lamps and their 5 filaments vary in manufacture so that it impossible to obtain uniform results try merely substituting new lamps for old ones.

The position of the original. lamp may often be accurately fixed by ordinary shop and laboratory photometric methods, but in the field such methods can not be followed and the apparatus necessitated thereby can not be used.

One of the objects of this invention is to provide an improved method of properly locating lamps.

Another object is to provide a method and means which readily lend themselves to field use.

Other objects and advantages will hereinafter appear.

An embodiment of apparatus whereby the improved method may be practiced is shown in the accompanying drawing.

The adjustable lamp support disclosed herein is claimed in my copending applica tion Serial No. 529,434, filed January 16, 1922.

The device for determining the position of the lamp is claimed in my copending application Serial No. 429,433, filed January 16, 1922. i

The views in the drawings are as fol lows Fig. 1 is an elevation of a rear view of a light unit showing the focus finder in place thereon.

Fig. 2 is a vertical section taken on line 22 of Fig. 1.

Fig. 3 is a view similar to Fig. 2, showing a fragment thereof.

Fig. 4 is an enlarged sectional view of a part of the lamp adjusting support, taken on line 4-4 of Fig. 2. i

Fig. 5 is a similar view to Fig. 4 taken on line 55 of 2.

Fig. 6 is a section of part of the focus finder taken on line 6-6 of Fig. 2.

Fig. 7 shows a view in side elevation of the conventional filament of an electric lamp.

Fig. 8 is a diagran'i of the focus finder with the lamp displaced, on the focal axis and forward of the focal point.

In all the views the same reference characters are employed to indicate similar parts.

To obtain the highest eiiiciency in the projection of light by lenses, reflectors. or the like. it is quite essential that the source of light,.such as the filament of an electric lamp, be placed at the exact focal point of the projector; when this has been achieved the light may be made, by use of a proper arrangement of lenses. to produce a beam of light in which the rays are in parallel lines, thus projecting a more intense and far reaching beam of light. By moving the lamp along the focal axis of the light projector towards the projector the rays may be made to outwardly diverge or flare while if the lamp be moved out of the focal point in the opposite direction the rays of light may thus be made to converge.

In railway signal systems, in different situations, the signal lamp units are required to project beams of light in which the rays are parallel; in other locations the rays of light must be diverging so as to extend over a relatively large light field at the objective point, and in others the light beam must be more concentrated at the point of application. For uniformity of appar-tus an economy of eqrupment, it is highly desirable that a Slllfile structure be .uiadc cajmble, bv

proper ad stinent. to meet the various requirements of It is furthermore necessary to be able to ascertain and to note the extent to which the field of illumination is extended or contracted, that is, the measure in degrees of digression from a beam of parallel rays. The in strument herein disclosed and the method of its operation is intended more particularly for readily establishing the filament of a new electric lamp in a lamp unit, in pre cisely the same location of the filament of the lamp initially installed in the unit, whereby it will produce the same results as the latter. although it may vary in some of its structural features or other characteristics from the original lamp.

The drawings show portions of a more or less conventionalsignal lamp unit in which it) is a part of the unit casing providing a ring 11 for a lens 12, and a ring 13 for a lens 14. In this doublet arrangement or lenses, when the filament 15 of the electric lamp is located at the precise focal point, as shown in Fig. 2, the rays of light projected there from will form a beam in which the rays will extend in parallel lines. If the light point 15 be brought nearer to the smaller lens the light beam will be more or less fan shape and if it be moved in the opposite di rection. the beam of light will be concentrated.

A means for moving the lamp and securing it in its desired position is accomplished by the following instrnmentality at bracket 17 carries lamp sockets 18 and 19, the lamp 16 is shown inserted in the lat ter, and is the active lamp of the unit. The bracket is carried by or is part of a tube or sleeve 20. which is threaded at one end. as at 21. i

A rotatable shaft carries at one end an eccentric 23 to which it is fixed thru the annular sleeve 23; at itsother end it is fixed to an eccentric 25 by a pin 26. These eccentrics form journals upon which the shaft is rotatably supported and while they are shown to be somewhat different in diametric dimensions, the throw or eccentricity of the two eccentrics is the same so that, upon rotation, the shaft 22 will be moved in parallel. lines around the axisof its movement. The shaft and sleeve 23 are provided with a screw driver slot 27 for convenience of rotation or they may be rotated bya wrench engaging the annular sleeve 23. The eccentric is rotatable freely in a socket 28 Which is a fixed part of. the frame 10. To retain theeccentric 25 in the socket it is provided with a groove 29 into which a screw 30 projects from the socket 28.

The eccentric 23 is rotatable in a ring 81 mascot which is part of a rearwardly extending arm 32. which also carries the eccentric hearing or socket 28. Arm 82 is bifurcated at its inner end prm'idiag supplementary arms 33 and 34 fixed to the frame 10 by screws 7.

A tube or sleeve 36 overlies a large portion of shaft 22 and is freely rotatable with respect thereto. It is provided with an axially parallel slot 87 into which a screw 38,

from the bracket sleeve 20. projects to permit the latter sleeve to be axially moved thereon and to cause said sleeves 20 and 30 to be rotated as one.

A nut 39, rotatable on the sleeve 2-36, is prevented froin being axially moved thereon by a screw 4L0, which extends therefrom into an annular groove all in the sleeve. The sleeve 36 is normally held in fixed position with respect to the frame 10 by a set screw 41 which passes thru a. hub d2 of sleeve 23. The screw ll is held in clamping position by a nut 43. The sleeve 23 is fixed by a set screw slat which passes thru the hub 45 of ring 31, which is a part of the frame 10. A check nut 4l6 securely holds the clamping set screw 44: in clamping position.

From the above description it will be manifest that the lamp 16 may be moved to any desired point in a plane transverse to the focal axis of the lens combination by rotation of the shaft 22 and its connected eccentrics and that itmay also be movedalong the focal axis by rotation of the nut 39 and fixed in its adjusted positions by the set screws 41 and 44.

it the time when the light signal unit is assembled, alamp 16 is placed in the socket l9 and its filament energized. The filament is then placed approximately at the focal point of the lens combination.

The beam of light from the outer lens is now measured photometrically. The lamp and filament are then movably adjusted and readings taken from the photometer until the exact focal point has been thus ascertained. whereupon the shiftable parts of the lamp adjusting device are locked in fixed positions by the set screws. Of course. if it is desired to have the signal unit project a flaring beam of determined degree the lamp and filament are adjusted accordingly. Any suitable method and apparatus for photometric calibration and measurement may be used.

After the lamp signal unit has been installed in service, it sometimes happens that a new electric lamp must replace the original and the filament of the new lamp must occupy the same position as that of the original electric lamp.

The original shop method of finding the desired location or focal point, cannot be pursued for placing a new lamp because the unit is supported on a pole or other inaccessible location and for this reason it is impracticable or impossible to follow the original procedure outlined above. 1

I have therefore provided a focus finder and a method for reestablishing the initial relation with a substitute electric lamp and its associated lenses.

The instrument consists of a small closed casing 50 having an observation aperture 51. A portion of its edge wall is iii-curved, as at 52, the curved portion extending something more than 90 degrees and having portions of its wall inclined at .45 degrees from the perpendicular, as at 53 and 54. A small lens 55 is secured in an opening in the curved portion 52 of the housing Wall vertically above the filament 15 and another similar lens 56 is located in an opening in said curved wall just 90 degrees removed. A light reflector 57 is secured to the wall 54:, inclined just 45 degrees from the focal axis of the lens 55. A similar mirror or reflector 58 is fixed in the same manner to the inclined wall 53 and inclined 45 degrees from the focal axis of the lens 56 so that the beams of light reflected from the mirrors or reflectors 57 and 58 will be in planes precisely 90 degrees in angular relation to each other.

A plate of ground glass 59 is placed in the path of the beam 60, of reflected light and located at right angles thereto, upon which to receive the image 15 of the lamp filament 15.

A plate of ground glass 61 is placed in the path of the beam 62 of reflected light from the lens 56 and located at right angles thereto, upon which to receive the image 15 of the lamp filament 15.

A reflector 62' is placed over the plate 61 and inclined substantially 45 degrees so that an observer looking thru the aperture 51 will see the two reflected images 15 and 15 as they appear in Fig. 1, when the lamp filament 15 is in the position occupied by the original lamp which is the focal point of the lens combination.

The plates 59 and 61 each have a longitudinally extending central line 63 which blend into the line 63 as they appear to the observer in Fig. 1. They each have a transversely extending line 64 and 65, respectively. When the images 15 and 15 are symmetrical with respect to the associated transverse lines and with respect to the single vertical line 63 as shown. the former relations of the light point of the lamp and lenses have been reestablished and the signal unit will operate with the new lamp in the manner as before its original lamp became defective.

Should adjustment be required to produce divergence of light rays of 5 degrees, 10 degrees or 15 degrees as exigencies of the case may require, at the field of illumination, means are provided for accurately ascertaining the degree to which the light beam will be laterally extended.

Fig. 8 shows the filament 15 moved toward the lens on the focal axis so that the angle ofthe light beam is raised above the line 65, in a manner clearly apparent, in which event the image 15" will be raised to the short lines 5, 10 or 15, according to the degree of beam expansion, on the plate 59, shown more clearly in Fig. 2-indicative of the respective degrees to which the light beam has been spread by the forward movement of the lamp 16.

Since. in the above example, the lamp is moved along the focal axis of the lens. there will be no disturbance of the light projected thrn lens 56; therefore the image 15 will remain on cross line 64:.

To adjust the instrument 50 to a lamp signal unit in which the electric lamp has been located, in the manner heretofore described, so that it may be removed and subsequently replaced with accuracy, the casing 50 has projecting forwardly therefrom a tapered stem 66, having a transverse notch 67 in its smaller free end. At approximately the proper position in the frame 10 a socket 68 is made, which is considerably larger than stem 66. A sleeve 69, the bore of which is tapered to neatly fit the stem 66, has one or more grooves 70 and a transverse pin 71 which the transverse notch 67 of the stem engages to prevent rotation of the stem and attached instrument.

hen the filament 15 has been properly located by adjustment of the instrument the latter is fixed and temporarily held, with the stem 66 and sleeve 69 in the socket 68, and with the image 15 and 15', as shown in Fig. 1. Then metal such as Babbitt metal, Zinc or lead, 72, is poured into the socket and around the sleeve 69 to hold the latter in place in the socket. The instrument will now visually show the true focal point of the lens, and may be removed and reinserted for subsequent use.

The instrument may advantageously be used in connection with a parabolic reflector, or other reflector.

While I have herein shown and described a single embodiment of the invention for the purpose of a clear disclosure, it is manifest that many changes may be made in the configuration and disposition of the parts within the scope of the appended claims.

Having described my invention what I claim as new and desire to secure by Letters Patent. is

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