US1653625A - Railway signaling apparatus - Google Patents

Description

L. O. GRONDAHL RAILWAY SIGNALING AP ARATUS Dec. 27, 1927.

2 Sfieets-Sheet 1 Original Filed Jan. '24. 1924 INVENTOR 2 Dec. 27, 1927.

I O. GRONDAHL.

RAILWAY SIGNALING APPARATUS Original Filed Jan. 24,1924 2 Sheets-Sheep 2 IN VENTOR aux-M Patented Dec. 27, 1927.

more!) STATES tenses PATENT OFFiCE.

LAES'D. 'GEONDAI-ZL, OF EITTSB-URGH,"EENNSYLVKNIA, LASSIGNOR TO THE UNION 72 E it NEvYLVANIA.

Continuation of application Seine-1N0.

f y invention relates to railway signaling al paratus, and particularly to apparatus of the type comprising roadside signals c011 trclled'hy track 'circuitswhich are responsive to the presence of trains on the track. I

The presentapplication is a continuation of my copending application, Serial No. 688,201, filed January 2t, 1924, for railway signaling apparatus, in so far as the "subjectmatter common to the two isconcerned.

will describe two forms of signalin t apparatus embodying my invention, and will then point out the novel 'tea'tures t-hereot in claims. I l

in the accompanying drawings, Figs. 1 and 2am diagrammatic views showing two terms ot railway signaling apparatus 'embodying my invention.

lftet'erring first to Fig. 1, the reference ch21 acters 1 and 1 designate the track rails of a stretch of railway track over which tra'liic normally moves in the direction indicated by the arrow. These track rails are diviced, by means of insulated joints 2, into a. plurality ofsuccessive-track sections A"B, ll- 0. etc. i I j Each track scection is provided with a suitable traclzway signal. As here shown each signal comprises three indicators such as'signal la as, designated by the reference characte I and it with exponents 'corresponoi to the location and arranged when energized to indicate proceecl, cautiou, and stop, respectively.

Each track section also provided with five thermo-sensitive relays designated by the reference characters H, F, J, K, and L, with exponents corresponding to the locations. Each such thermo-sensitive relay coinprises a heater 8 and an element 9 of thermo-sensitive material, that is, material which has the characteristic of varyingfi-ts elec ric'al resistance in response to variations the temperature of the element. Each therinc-sensitive element 9 is electrically insu- "-ated from the associated heater '8 but is subjected to variations in the temperature'of such heater. The parts are so proportioned that the resistance of each thermo-sensitive element 9 is comparatively high when the associated heater is die-energized butthat who the associated heater is energized, the recipe. ture of the thermo-sensitive element 'TCH 8c SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPQRATION RA-IIELW'A'Y SIGNALING APPARATUS.

688,207, filed January 24, 1824. This application filed May 18, 1926. Serial No. 109,869.

is increased and the resistance of theelemeat reduced to a -comparativ'ely low value. v I

Referring particularly to the apparatus located at point A, the right-hand terminal of the heater 8 of thermo-sensitive relay J and the leftdi'andterminal of heater 8 of 'thermo-sen-sitive relay K are connected togetheijat common terminal cl. This common terminal d is connected, through heater 8 of relay Lflwith rail 1 of the section to the left of point A. The left-hand terminal of heater 8 of relay J5 is corrected with will of this section through the medium of a deice 1- which'permits current to flow through the heater of relay J in only one direction. This device. comprises a unidirectional current carrying device or asymmetrical unit of any desired form and may conveniently be a copper oxide asymmetrical unit such as described in an application for United States Letters Patent, Serial N 1,111, filed January 7, 1925, by Lars O. Grondahl for unidirectional current carrying devices. The right-hand terminal of heater 8 of relay K is connected with rail 1 through an asymmetrical unit 5. :It should be noticed that unit is oppositely disposed with respect to unit 4, that is, these two units conduct most readily in opposite directions and hence, when rail 1 is positive with respect to rail 1", current flows throughthe heaters of relays J and L whereas, when rail 1 is positive with respect to rail 1, current flows through the heaters of relays K and L Energy is supplied to the apparatus at each location from a line transformer designated by the reference character TV with a suitable exponent and having a primary winding 10 constantly supplied with alternating currentfrom some suitable source such as an alternator D, over line wires 3 and 3. 1

'VVhen relay J is energized, lamp G is energized, current passing from secondary 13 ot transformer T through wire 16, heater 8 of relay H wire 17, 't-hermosensitive element 9 of relay J wire 18, lamp G and wires 19 and 20 back to secondary 13 of transformer-T "Under this condition a proceed indication is displayed at location A. When relay '1 is "energized, lamp Y is lighted to display a caution indication, current then flowing from secondary 13 of transformer T through wire 16, heater 8 of relay H wire 17, thermo-sensitive element9 of relay K, wire 21, lamp Y and wires 19 and'2O back to secondary 13. of transformer T It will be noticed that when either indicator Gr or Y is energized, relay H is also energized.

Lamp R is provided with a circuit which passes from secondary 12 of transformer T through wires 22 and 23, resistance 24, wire 25, lamp R wire 26, heater 8 of relay F and wire 27 back to secondary 12 of trans former T This circuit is so adjusted and proportioned that lamp R is normally enen gized. When relay H is energized, however, current flows from secondary 11 of transformer T through wire 23, resistance 24, wire 28, thermo-sensitive element 9 of relay H and wire 29 back to secondary 11 of transformer T The parts are so arranged and proportioned that the voltage drop in resistance 24 due to current flowing over this circuit is equal in magnitude and opposite in direction to the electromotive force applied to lamp R by secondary 12. It follows that when relay H is energized, the electromotii-e force applied to lamp R is neutralized by the voltage drop in resistance 24 and lampR is therefore de-energized. But I have already explained that relay H is energized when either lamps G or Y is energized, and it is therefore obvious that when either lamp G or Y is lighted, lamp R isextinguished. I

Relays L and F control the supply of track circuit current to section AB in the following manner. The right-hand terminalof winding 14: of transformer T and the left-hand terminal of winding 15 of this transformer are connected, by wire 32, with rail l of section A-B. The left-hand terminal of winding 1% is connected with rail 1 of section AB, through wire 30, thermosensitive' element 9 of relay L wire 31, and an asymmetrical unit (3, to rail 1. The righthand terminal of winding 15 is connected, through wire 33, thermo-sensitive element 9 of relay F wire 34, and asymmetrical unit 7 to rail 1. Units 6 and 7 are similar to units a and and it will be clear from the drawing that when relay L is energized, as when lamp G or Y is energized, current is supplied to section A.B by winding 14. Due to unit 6, however, current can flow in one direction only through this circuit and rail 1 is therefore positive with respect to rail 1 Under these conditions, current of what I shall term normal relative polarity is supplied to section AB. Similarly, when relay F is energized, as when lamp R is lighted, current is supplied to section AB by winding 15, but under this condition rail 1 is positive with respect to rail 1. Under these conditions current of what I shall term reverse relative polarity is supplied to section AB.

As shown in the drawing, a train, indicated diagrammatically at V, occupies the section to the left of A. Current is therefore shunted away from the relays J and K and relays J K and L are de-e-nergized. As a result, relay H is ole-energized, so that lamp R is lighted and relay F is energized. A stop indication is therefore displayed at point A, and track circuit current of reverse relative polarity is supplied to section AB by winding of transformer T Relay K is therefore energized and relay L is also energized, but relay J is cle energized. As a result, lamp Y is energized and a caution indication is displayed at point B. The energizationof relay K also energizes relay H so that lamp B is de-energized but relay F is tie-energized. Track circuit current of normal relative polarity is therefore supplied to section B-C from winding 14 of transformer T This track circuit current flows through heaters 8 of relays L and J C and energizes these re lays but relay K is de-energized. Lamp G is therefore energized and relay H is also energized. It follows that lamp B" and relay F are both de-ene-rgized. Aproceed indication is therefore displayed at point C and track circuit current of normal relative polarity is supplied to the track section to the right of point C by winding 14 of transformer T Referring now to Fig. 2, the apparatus is similar to that described for Fig. 1 except that the thermo-sensitive relays J, K, F and H are constructed so that the heater f each relay is in electrical contact with the thermo-sensitive element 9 of such relay. TVhen the heater is energized therefore the current can flow through the thermo-sensitive element to the heater of the relay.

The heater 8 of thermo-sensitive relays J and K for each section are connected in parallel across the rails adjacent the entrance end of the corresponding section through the asymmetrical units 4 and 5 as in Fig. 1, but the common terminal cl of these heaters is connected directly with the rail 1 instead of through the heater 8 of a relay L as in the preceding figure. Referring particularly to the apparatus located at point A, the circuit for lamp G may be traced from secondary 11 of transformer T through wire 36, lamp G wire 43, thermo-sensitive element 9 and heater 8 of relay J wires 39, 10 and a1, heater 8 of relay H wire 42, and resistance 2 1 back to secondary 11 of transformer T This circuit is closed only when relay J is energized. When relay K is energized current flows from secondary 11 of transformer T through wires 36' and 37, lamp Y wire 38 thermo-sensitive element 9 and iio lili) emma 7 heater =8 of relay K wires 39, 40 and '41,

heaterB of relay H wire 42, and resistance is energized.

ondary "of transformer T through wire 41%, lamp B, heater 8 of relay F wire a6, a portion of resistance 2st, and wire 6.0 "hack to secondary 12 of transformer The parts are "so. proportioned when current is being supplied to either of the lamps G? or 'Y+*:the potential drop across the portion of resistance '24 which is included in the circuit for lamp B t-is .equal in magnitude and 0p posits in direction to'etheelectromotive force supplied by secondary 12 of transformer'T When either of lamps G 0.1: Y is lighted, then,:no current flows the circuit for lamp R and this lamp and relay F are then both dc-energized; When relays J and'K are both cl'e energized, however, so that no cur rentflows from secondary ll through resistance 24:, the electromotive force supplied by secondary .lQfof transformer T supplies a current to the circuit of lamp R which energizes thislanrp and the heater 8 of relay F T re left-hand terminal secondary 1-5 of transformer .T is constantly connected with the right-hand terminal of secondary lla-nd is also connected by means of wire 51 with rail 1 of section AB; The right-hand terminal of secondary 15 is connected through wire 48, asymmetrical'unit 7, wire 49, thermo-sensitive element 9 of heater 8 of relay H and wires ll, 40 and 50 to the rail 1 of section A-B. It follows that when relay H is energized, current of normal relative polarity is'supplied to the rails of section AB. The left hand terminal of secondary 'llis connected through wire '54, asymmetrical unit =6, wire 53, thermo-sensitive element 9 and heater 8 of relay F and Wires 52, 40 and '50 to rail 1 of section AB. When relay F is energized therefore,current of reverse relative polarity is supplied to the rails of section A B from secondary 14L.

As shown in the drawing the section to the left of point A is occupied by a train V. Current is'therefore shunted awa from the heaters 8 of relays J and K and these'relays are (lo-energized so that no current can Lamp R flow through lamps G or Y is therefore energized to give a stop indication and relay F is also energized but relayH is de-energized. Current of reverse relative polarity is therefore supplied to the "rails of section AB from secondary 14 of transformer T. This currentilows through asymmetrical unit 5 to heaterv 8 of relay K but cannot flow through asymmetrical unit The circuit for lamp R passes from secv 4 to heater '8 of relay J Relay J is therefore de-ener'gized, and relay K is energized so that current flows from secondary 11 of transformer T through lamp Y' thereby giving :a caution indication. Relay H is therefore energized, but the current flowing through resistance-2415mm secondary llneutralizes the electromotive force supplied by secondary 112 of transformer T sothatlamp R is extinguished and relay F is de-en'en gized. Current of normal relative polarity is therefore supplied to the rails of section B' O from secondary 15 of "transformer T This current energizes relay J but relay .K is de-energized. Current therefore flows from secondary .11 of transformer. T through lamp G9, lighting thislam'p to give a proceed indication. Relay H is energized and relay. F is de-energized and lamp R isextinguished. Current ofnormal relative polarity is th'erefore supplied to the rails of the section-to the right of point C by secondary of transformer T One advantage of the apparatus shown Fig. 2 over th-atshown in Figure l isth'at in Fig. 2 only one thermo-sensitive relay is energized at a time at the entrance end of each track section and the power required to operate the apparatus is therefore less thanin Fig. 1, where two thermo-sensitive relays are always energized at this point.

Other advantages are the savings resulting from the elimination of one thertmo-sensitive relay and one winding of transformer T for each signal location.

Although .I have herein shown and described only two forms and arrangements of railway signaling. apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

I claim is:

1. In combination, a forward and a rear track section, thermo-sensitive relays associated with said forward section, means controlled by said thermo sensitive relays for supplyingsaid rear section with track circuitjcurrent of one relative polarity or the other depending on tralhc conditions in said Having thus described my invention what forward section, traffic governing means for 3,111- coinbinat-ion, a stretch of railway track, means for at times supplying said stretch with track circuit current or one relative polarity or the other, thermo-sensitive sensitive relay and an asymmetrical unit for said rear section responsive to such current, and tratfic governing means for said rear section controlled by said relay and byv said unit. 7

5. In combination, a stretch of railway track, means responsive to t'aiiic conditions in advance for supplying said stretch with track circuit current of one relative polarity or the other, a thermosensitive relay connected with said stretch, an asymmetrical unit interposed between said stretch and said relay, andtraiiic governingmeans con trolled by said relay.

6. In combination, a stretrhoi": railway track, two sources of energy, two tn'ermosensitive relays one for connecting each said source with the railso'f the stretch when the associated relay is energized, means for energizing one said relay or the other in accordance with traffic conditions, an asymmetrical unit interposed between said stretch and one said source, a second oppositely disposed asymmetrical unit' interposed between said'stretch and the other said source, and trafiic governing means responsive to the relative polarity of the current in said stretch. a y

7. In combination, a stretch of railway track, two thermo-sensitive relays each having a heater, means for connecting one terminal of each heater to one rail of said stretch and for connecting the other terminal of each heater to the other rail, an asymmetrical unit interposed between one heater and one rail of said stretch, an'oppositely disposed asymmetrical unit interposed between the remaining heater and one rail of the stretch, and traiiic governing means con trolled by said thermo-sensitive relays.

8. In combination, a stretch of railway track, means for supplying said stretch with track circuit current of one relative polarity or the other in accordance with traiiic conditions, 2. thermo-sensitive relay, means including an asymmetrical unit for connecting said thermo-sensitive relay with said stretch, and trafiic governing means controlled by said relay.

9. In combination, a stretch of railway,

* track, two thermo-sensitive relays, an asymand means controlled by said relays andby said asymmetrical units for supplying-said stretch with track circuit current of one relatively polarity or the other in accordance with trailic conditions. v v

10. In combination, a stretch of railway track, two thermo-sensitive relays,.an asymmetrical unit associated with each said relay, means controlled by said relays and by said asymmetrical units for supplying said stretch With track circuit current of. ione relative polarity or the otherin accordance with traiiic conditions, and traffic governing means responsive to the polarity of such current. V 1

11. In combination, a stretchof railway track, two thermosensitive relays, an asymmetrical unit associated with each suchrelay, andmeans controlledby said relays and by said asymmetrical units for supplying said stretch with track circuit current of one relative polarity or the other in accordance with traliic conditions; v 12. In combination, a stretch'of railway track, means for supplying said stretch with track circuit current of one relative polarity or the other in accordance with trat'fic'conditions, a thermo-sensitive relay, means includin an asymmetrical unit for connecting said thermo-sensitive relay with said stretch, an. indicator controlled by said thermo-sensitive relay, and a second indicator arranged to be tie-energized when said first indicator is energized.

.13. In combination, a stretch of railway track, means for supplying said stretchwith track circuit current of one relative polarity or the other in accordance with tra fiicconditions, a trackway signal comprising a plurality of indicators, a thermo-sensitive relay for controlling one said indicator, means including an'asymmetrical unit for con necting said relay with said stretch, a second thermo-sensitive relay for controlling the second said indicator, and means including an asymmetrical unit oppositely disposed with respect to said first unit for connecting said second thermo-sensitive relay withlthe stretch.

ltpIn combination, a stretch of railway track, means for supplying said stretch with track circuit current of one relative polar- I ity or the other in accordance with traffic conditions, a trackway signal comprising a plurality of indicators, a thermo-sensitive relay for controlling one said indicator, means including an asymmetrical unit for connecting said Yrelay with said stretch, a second thermo-sensitive relay for controlling the second said indicator and means including an asymmetrical unit oppositely disposed with respect to said first .unit for connecting said second thermo-sensitive relay with the stretch, and a third indicametrical unit associated with each said relay,

tor arranged tov be de-energized when either said first or said second indicator is ens-r gi-zed Y 1-5. In combination, a stretch of railway track, a trackway signal responsive to trafficconditions, niea-ns including a thermosensitiv-e relay and an asymmetrical unit for supplying track circuit current of one characteristic to said stretch when said nal is displaying one indication but not when said signal is displaying a different indication, and traffic governing means rcsponsiveto said current.

1 6. In combination, a s retch'of railway track, a traclrway signal responsive to traffie conditions, and means therm'o-sensitive relay and an asymmetricalunit for supplying track circuitcurrentof one relative polarity to said; stretch when the signalis displaying one indication and for supplying traek ci'reni-t current of the other relative polarity to the stretch when the signal is displaying a different indica tion.

17. In combination, a stretch of railway track, means for supplying said stretch with track circuit current of one relative polarit-y or the other in accordance with trafic condition, two thermo-sensitive relays each comprising a heater, means for connecting said heaters in parallel across the rails of said stretch, two asymmetrical units one interposed between each heater and one rail of the stretch, and traficgoverning means controlled by said thermo-sensit-ive relays.

18. In combination, a stretch of railway track, means for supplying said stretch with track circuit current of one relative polarity or the other in accordance with trafiic conditions, two thermo-sensitive relays each comprising a heater, means for permitting current from said stretch to flow only in one direction through one heater and only in the other direction through the remaining heater, and traffic governingmeans controlled by said thermo-sensitive relays.

19. In combination, a stretch of railway.

track, means for supplying said stretch with track circuit current of one relative polarity or the other in accordance with traflic conditions, two thermo-sensitive relays each comprising a heater, means for connecting said heaters in parallel across the rails of said stretch, two asymmetrical units one interposed between each heater and one rail of the stretch, and two indicators one controlled by each said thermo-sensitive relays.

20. In combination, a stretch of railway track, means for supplying said stretch with track circuit current of one relative polarity or the other in accordance with traffic conditions, two thermo-sensitive relays each comprlsing a heater, means .for connecting said heaters n parallel across the ralls of said including a stretch, twoasymmetrical units one interposed between each heater and one rail of third indicator arranged to be de-energized wl'ien'either; of said first two indicators is encrgi /ied. i l

- 21. In combination, a stretch of railway rack, means for supplying said stretch with track circuit current of" one relative polarity or tl other in accordance with traffic con dit-ions, two thermo-sensitive relays each comprisinga heater; means for connecting said heaters. in parallel across the rails of said, stretch, two asymmetrical units one in terposed between each heater and one rail of the stretch, twoindicators one controlled by each said thermo-Ccnsitive relay, :1 third thGIliIO-SGDSLIVB' felily controlled by said first two: thermo-sensitive relays, and a third indicator controlled by said thirdi thermosensitive relay.

22. In combination, a stretch of railway track comprising a forward and a rear section, mean-a for supplying said forward section with track circuit current of one relative polarity or the. other in accordance with traflic conditions, a first and a second thermosensitive relay each comprising a heater,

connected across the rails of said forward section, two asymmetrical units oppositely connected in series with said heaters respectively, a third and a fourth thermo-sensirive-relay; a circuit for the heater of said third relay including a source of energy,a resistance, and the thermo-sensitive elements of said first and second relays in parallel; a circuit for the heater of said fourth relay including a second source of energy and a portion of said resistance; and means for supplying the rails of said rear section with current of one relative polarity or the other according as said third relay or said fourth relay is energized.

23. In combination, a stretch of. railway track comprising a forward and a rear section, means for supplying said forward section with track circuit current of one relative polarity or the other in accordance with trafiic conditions,'a first and a second thermosensitive relay each comprising a heater connected across the rails; of said forward section, two asymmetrical units oppositely connected in series with said heater-s respecincludinga second source of energy and a portion of said resistance; a third source of energy, means for supplying current of one relative polarity to the rails of said rear section from said third source when said third relay is energized, a fourth source of energy and means for supplying current of the opposite relative polarity to the rails of such rear section when said fourth relay is energized. p I

12%. In combination, a stretch of railway track comprising a forward and a rear section, means for supplying said forward sec tion with track circuit current of one relative polarity or the other in accordance with trafiic conditions, a first and a second thermosensitive relay each comprising a heater connected across the rails of said forward section, two asymmetrical unit-s oppositely connect-ed in series with said heaters respectively,a third and a fourth thermo-sensitive relay a transformer comprising a primary constantly supplied with alternating current and four secondaries; a circuit for the heater of said third relay including one of said secondaries, a resistance and the thermosensitive elements of said. first and second relays in parallel; a circuit for the heater'of said fourth relay including a secondsecondary of said transformer, and a portion ofsaid resistance, means for connecting the common terminal o'fthe third and fourth transformer secondaries with one rail of said rear section, means includin an asymmetrical unit and the thermo-sensitive element of said third relay for connecting the free terminal of said third secondary with the other rail of the rear section, and means including a second oppositely disposed asyme metrical unit and the thermo-sensitive ele-- ment of the fourth relay for connecting the free terminal of'the fourthtransformer secondary with such other rail of said rear section. V

In testimony whereof I afiix my signature,

LABS o. GRONDAHL.

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