US1758179A - Light signal - Google Patents

Description

May 13, 1930.

c. s SNAVELY LIGHT SIGNAL Filed Oct 19, 1923 '2 Sheets-Sheet 1 INVENTOR'.

c. s. SNAVELY May 13, 1930.

LIGHT SIGNAL Filed Oct. 19/ 1925 2 Sheets-Sheet INVENTOR'.

Patented May 13, 1930 UNITED STATES PATENT OFFICE i CLARENCE S. SNAVELY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TOTHE UNION swr'rcn & SIGNAL COMPANY, or SWISSVALE, PENNSYLVANIA, A conrozaArroN or PENNSYLVANIA LIGHT sreNAL Application filed October 19, 1923. Serial No. 669,488."

My invention relates to light signals, and is' particularly adapted for signals of this type used in railway trafiic controlling systems. 1 p

I will describe one form of light signal embodying my invention, and will then point out the noval features thereof in claim.

In the accompanying drawings, Fig. 1 is a view showing in front elevation one form of light signal embodying my invention. Fig; 2 is a rear view of the signal shown in Fig. 1. Fig. 3 is a vertical sectional view along the line TIL-III of Fig. 2. Fig. 4e is a horizontal sectional view on the line IV-IV of Fig. 3, looking in the direction of the arrows. Fig. 5 is a detail view showing, in elevation, the back light reflector for the signal illustrated in the first four views. Fig. 6 is a detail view showing the bacl 4 light housing as viewed from the right in Fig. 2.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1, Zand 3 the signal comprises a triangular front plate 1. The front plate 1 is provided at its top with a yoke 1, and at its bottom with two lugs 1", by means of which the signal may be adjustably mounted in any desired manner. Three light units R, Y and G are attached to plate 1 by means of bolts 4. These light units are so mounted that their centers are at the vertices of a triangle of which one vertex is di- I rected downwardly. Each light unit is containedjn a shell designated by the reference character 2 with an-exponent corresponding to the unit, and a cover designated by the 7 reference character 3 also with a suitable exponent. These shells 2 are integral with front plate 1.

- The front plate 1 is provided with three apertures one immediately in front of each light unit. Each aperture is provided with a lens structure forming part of the light unit and which, as here shown comprises a front lens and a back lens designated by the reference characters 11 and 12,'respectively, with exponents corresponding to the units. These lens structures are supported in a suitable frame 15 which is supported on plate 1 by bolts 1. Behin car-b lens structure is an respective shells 2.

nal and passing through electric lamp, designated by thereference character 13, and also forming part of the light unit, the filament of this lamp being- I located at the focus of the associated lens combination. Each front lens 11 is protected from snow and from the direct rays of'the sun by means of a hood 14 of suitable shape supported by the front plate 1.- In addition to the lamp 13, light unit R contains a terminal board C comprising binding posts 14 which are connected with the lamps 13 of the.

various units. v I I 7 Supported by front plate 1 and located in the center of the triangle defined by the three light units is a pin which projects towards the back ot the signal and which terminates in a threaded tip 5. A- Y-shapedspider B i is provided with a hole at its center to. ac-

commodate the pin 5. Each of the covers 3 is attached, by means of a rivet 6 to the'end of one leg of the spider B. It will be noticed that with this method of connection, relative I movement of any cover with respect to any other cover is impossible. A nut 8 is threaded on the tip 5 of pin 5 to force the spider B to the right as viewed-in Fig. 3 thus clamping the cove-rs 3 against the edges of their with a hasp 9 arranged to latch over a staple 10 in the lower leg of spider B. The staple 10 is provided with a hole 10' to receive the yoke of a padlock by means of which the covers may be locked in position since it is obvious that if nut 8 is screwed up and locked in position the. covers cannot be removed. Since the covers are thus rigidly fastened together by .means of spider B it is plain that no one'cover can be moved away from its associated shell without also removing the other covers from their shells.

Since no one cover 3 can be removed without also removing the other two covers, there is no possibility of a false indication due to transmitted light originating behind the sigone of the colored lenses '11. That is to say, in the event of such a light behind the signal and one of the units being open, the remaining unlts would also The nut 8 is provided be open and all three lens structures would be equally illuminated.

In order to accommodate the terminal board C the 'shell 2 is larger than shells 2 and 2", and cover 3 is therefore larger than cover 3 and 3". It follows that the larger 5 mass of cover 3 biases this cover to the position shown in the drawing and hence all covers normally occupy positionsimmediately behind their respective units. 7

Means are provided for imparting a dis- 1g tinctive' color to the beam'of light projected from each light unit. This may be done by givin a distinctive 'color to one lens, as 11,

of'eali lens combination. For example, 11

may be made of green glass, 11 of yellow glass, and ll 'of red glass. These colors are in accordance with standard practicein railway signaling and correspond to indications ofprocoed, caution and stop, respectively.

As is well understood in railway signaling practice, the control of the signal is usually such that as a train passes the signal the lamp 13 is lighted and the signal projects a beam of red light to indicate toga following train that the block protected by the signal is occupied. It is frequently desirable that'an observer located on the train should be able to determine that the stop indication is being displayed after the train has passed the signal. For this reason I provided a back light for unit B which I will now describe. At-

tached to the frame 15 of'lenses 11 and 12 is a sheet metal member 16 carrying a collimating lens 17 so disposed as to project a beamof light from lamp 13 toward the right as viewed in Fig. 2. A housing 18 is attached by means of bolts 18 to the side of shell 2 of unit R. This housing is provided with a transparent lass screen or window 19 which is protected by a hood 20. Immediately inside of window 19 and supported also by housing 18 is a reflectordevice D. As best shown in Fig. 5, this device comprises two side rails 21 and 21 and a plurality of transverse reflectors 22 fastened at their ends to located side by side and the third unit located below and equally distant from the other two units, said lamps being adapted for individual illumination and the lenses of the three units being distinctively colored, enclosing means for said units including a cover for the back of each unit, a Y-shaped spider having one'said cover attached to each leg thereof and means for pivotally attaching said spider to said front plate, the-cover for the lower unit being heavier than the other covers so that said spider is biased by gravity to a position where in each cover registers with its associated unit.

Intestimony whereof I aflix my signature.

CLARENCE S. SNAVELY.

'45 these rails. These reflectors are here shown as strips-of metal having their upper surfaces (Fi 5) highly polished. I The signal is so as sem led that the reflector device D is inter- /posed in the beam of light projected from 50, lamp 13 by collimating lens 17 5 and the reflectors 23 are so disposed that this beam is redirected toward the rear of the signal through window 19. The path of this beam is indicated by the dot-dash lines on Fig. 4.

One surface of window 19 may be frosted or lightly sand-blasted for diffusing the light from reflector device D. It will be noticed that due to the angular position of window 19 the condition of energization of unit R may thus be observed in the rear of the signal,

from the right hand side of the signal as viewed in Fig. 2, or from any point between these two positions.

Although I have herein shown and described only one form of light signal emwithin thescope of the append" invention, what

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