US1641768A - Audible signal for railway braking apparatus - Google Patents

Description

v 1,641,768 p 1927- L. v. LEWIS AUDIBLE SIGNAL FOR RAILWAY BRAKING APPARATUS Filed July 17, 1926 INVENTOR I Patented Sept. 6, i927.

sis rrsnr LLOYD v.1.nwrs, on Enenwoon BOROUGH, PENNSYLVANIA, AssreNon TO THE UNION SWITCH & SIGNAL COMPANY, OF SVJIS OF fENNSYLVANIA.

SVALE, FENNSYLVANIA, A CORPORATION AUDIIBLE SIGNAL FGR RAILWAY BRAKING AE'PARATUS.

Application filed July 17,

My invention relates to railway automatic train control apparatus, and particularly to apparatus of the type wherein time. interval elapses after a stop. indication is received before a brake application is incurred. One feature of my invention is the provision of means for giving an audible signal during this time interval, so that the engine man may be on the alert to prevent anautomatic brake application reducing the speed or acknowledging the restrictive indi cation.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is view showing one form of apparatus embodying my invention.

Referring to the drawing, the apparatus here illustrated, all of which iscarried on a railway train, comprises a reservoir A, which is normally charged with fluid pres sure toprevent an automatic brake application, but the pressure in which is reduced to brake applying value under unsafe trafflc conditions at a rate dependent upon the speed of the train. Usually this reservoir will be so controlled that as the speed of the train decreases, the rate of pressure reduction decreases; For example, if the restrictive signal indication is received when the speed is miles per hour, the brake application maybe incurred 5 seconds thereafter, while if the restrictive signal indication is received while the speed of the train is 20 miles per hour the brakes may apply seconds thereafter, the delay period being of proportionate intermediate values at speeds intermediate the limits specified. One form of apparatus for cont-rolling this reservoir in the manner specified and for causing a brake application when the pressure in the reservoir is reduced to a given value, is shown in United States Letters Patent Reissue No. 16,083, granted to Frank H. Nicholson'on May 26, 1925, wherein two such reservoirs are disclosed, one of which is designated T and the other of which is designated T The reference character B designates a whistle, and the reference character 6- designates a whistle-operating reservoir. The supply of fluid pressure from the reservoir A to the reservoir C and subsequently from 1926. Serial No. 123,085.

the reservoir C to the whistle Bis controlled by a. valve D.

The valve D comprises a body member 3 having a chamber 12 provided with two oppositely disposed seats 6 and 8. The relatively small seat 6 communicates withthe whistle B through a port 5 and a restricted orifice 7, while therelativelylarge seat 8 communicates with the brake controlling reservoir A through a port 9 and pipes 2 and 1. The chamber 12 communicates with the whistle operating reservoir C by a pipe 4. Located-in the chamber 12 is a diaphra m designated as a wholeby the reference character 10, and comprising a central position normally engaging the valve seat 6, as well as a thin flexible flange normally resting on the valveseat 8. The entire diaphragm is preferably made of' rubber. This diaphragm is normally in the condition shown in the drawing, wherein both the ports 9 and 5 are closed, but it may bulge downwardly as a whole to open theport' 5 to chamber 12 and so to reservoir C, and

the flange 10 may also. bend upwardly to open communication between th the pipe 4.

I- will first assume that the brake controlling reservoir A is at atmospheric pressure and that the pressure in this reservoir is then increased. As the pressure in reservoir A increases, the flange' IO of the diaphragm 10 will bend upw-ardly'to admit e port 9 and pressure to reservoir 0, so that when the pressure in reservoir A reaches its maximum value thereservoir G will containfluid pres sure at substantially the same value. During this time the portion 10? of the diaphragm 10 has remained in contact with the valve seat 6 so that the whistle B has been silent. I will next assume that a restrictive indication is received, so that the pressure in the reservoir A decreases. The pressure above the valve member 10 isnowgreater than that below this member, so that the diaphragm 10 bulges downwardly away from the valve seat 6, thereby admitting fluid pressure from the reservoir C to the whistle B and sounding this Whistle to inform the engineman that a restrictive indication has been received. The whistle will blow as long as the pressure in reservoir A continues to reduce, andduring this time the engineman may either reduce the speed below the brakes but the to brake applying value under unsafe trafvalue required bythe particular indication which has been received, or he may take other stepsto prevent an automatic application of the brakes. One form of apparatus whereby the engineman may prevent a brake application during the interval that the whistle is blowing is shown and described in the aforesaid Nicholson Reissue Patent No.

Preferably a gauge E is connected with the reservoir A by pipes 11 and 1 to show the engineman the actual pressure in this reservoir and to inform him as to approximately how long he may wait'after a restrictive indication is received before taking steps to prevent an automatic application of the brakes.

Although I have herein shown and described only one form of apparatus emb0dyo ing my invention, it is understood that various changes and modifications may be made therein within the scope of the appended 7 claims Without departing from the spirit and 1 fic conditions at a rate dependent upon the speed of the train,,a whistle, a whistle operating reservoir, a valve having a chamber communicating with said whistle and with saidtwo reservoirs, and a flexible diaphragm in said chamber for connecting said-whistle operating reservoir with said brake controlling reservoir while the pressurein the lat-V ter is increasing and for connecting the whistle operatingreservoir with the whistle while the pressure inthe brake controlling reservoir is decreasing. I

2. Train carried governing comprising a brake controlling reservoir which is, normally charged with fluid pressure to prevent automatic application of the apparatus brakes but the pressure in which is reduced to brake applying value under unsafe trafiic conditions at a rate dependent upon the speed of the train, a whistle, a whistle operating reservoir,'a valve having a chamber communicating with said whistle operating reservoir and provided with two oppositely disposed seats communicating respectively with said whistle and said brake controlling reservoir, and a flexible valve member normally engaging both of said seats but capa bl-e of bending to permit charging the whistle operating reservoir while the pressure in the brake controlling reservoir is increasing and cap able'of bulging away from the whistle seat to vent the whistle operating reservoir to the whistle while the pressure in the brake controlling reservoir is decreasing.

3. Train carried governing apparatus comprising a brake controlling reservoir which is normally charged'with fluid pressure to prevent automatic application of the brakes but the pressure in which is reduced to brake applying-value underunsafe traffic conditions at a rate dependent upon the speed of the train, a whistle, whistle operating reservoir, a valve having a chamber communicating with said whistle operating reservoir and provided with two oppositely disposed. seats communicating respectively with said whistle and said brake'controlling reservoir, the whistle seat being relatively, small, and the other seat being relatively large, and a diaphragm having a central portion normally engaging said whistle seat and a flexible flange normally engaging the other seat,.said flange being capable of bending in wardl to ermit char 'in the whistle 0 erating reservoir while the pressure in the brake controlling reservoir is increasing, and said flange being also capable of permitting the central portion to bulge away from theseat to vent the whistle operating reservoir to the whistle while the pressure in the brake controlling reservoir is decreasin In testimony whereof I'allix my signature.

LLOYD v. L'EWIS.

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