US1599470A - Railway signaling system - Google Patents

Description

Sept. 14, 1926. 1,599,470

A. E. Huw

RAILWAY SIGNALING SYSTEM Filed Nov. 6. 1924 2 Sheets-Sheet 1 Hal.

G LT

Sept. 14 1926.

A. E. HUDD RAILWAY SIGNALI NG SYSTEM Filed NOV. 6, 1924 2 Sheets-Sme?I 2 Patented Sept. 14, 1926.

UNITED STATES PATENT OFFICE.

ALFRED ERNEST HUDD, OF NEW BRIGHTON, ENGLAND, ASSIGNOR TO AUTOMATIC TELEPHONE MANUFACTURING COMPANY, LIMITED, OF LIVERPOOL, ENGLAND.

RAILWAY SIGNALING SYSTEM.

Application tiled November 6, 1924, Serial No.

The present invention relates to improvements in or relating to alternating current track circuits and more particularly coucerns the provision of special relay arrangements in place ot the usual type of alternating current relays which require a large operating current. and can only be operated over comparatively small lengths of track.

It has previously been proposed to use .in alternating current track circuits vibratory or alternating current to which a relay` responds to etl'ect a rectiication so that a direct current relay can be operated thereby. In such arrangements dilticulties arise .in connection with the means for responding to the frequency ot alternating current supply. It has been usual to provide a tuned reed for this purpose in order to ensure that the relay will not respond to alternating currents ot frequencies different -troni that ot', the signaling',r current.

An important feature of the present iavention is that the vibrating reed ot the responding relay is not tuned, being in iti-.ict substantially aperiodic. Partly in order to render the direct current neutral relay immune to currents of diil'erent frequency and partly to enable alterations in the phase ot the current lowing over the track to be determi ned, the vibrating relay which responds to the alternating current on the track is arranged to rectify alternating currentsupplied independently of the track but from the saine source as the current which feeds the track. As satisfactory rectilication is dependent upon the vibratory member mov` ing in correct phase with the alternating current to be supplied, a 'further important feature is the provision of phase adjusting means. One torni of phase adjustment is to inserta condenser or an inductance in series with the responding relay or in series with the feed circuitl or both, a condenser having the additional advantage ot protecting the alternating current apparatus, namely, the feed transformer secondary or the responding relay from an accidental connection beingr established between the live rail and the track rails. The responding relay is preferably otl the type described in British speciication No. 156,353 and such a relay has the additional advantage over relays with tuned reeds that the phase may be adjusted very accurately and very readily. In this construction. the polarizing flux is provided by 748,138, and in Great Britain January 19, 1924.

a U-shaped permanent magnet, each limb of which carries two pole pieces and corre spending coils. The armature is pivoted substantially at its centre otgravity, so at to be practically aperiodic and as may ha seen from the tigures, in either of its operated positions it extends diagonally between pole pieces ot opposite polarity. Moreover the magnet and operating coils are pivoted about the same axis as the armature and adjustment is then readily ett'ected by rotating the coils slightly with respect to the armature, for instance, by means ot a threaded screw operating against the action of a restoring spring. Phase variations in alternating current track circuits have always been a considerable source of trouble and have necessitated somewhat expensive mechanism on account ot the itact that heavy currents have been used which give rise t0 much larger variations of phase than the small currents required by the invention and further that the line phase adjustment could not be atlected at the receiving end, lith the present invention the lineman has only to place a voltineter across the terminals of the neutral relay and adjust. the responding relay nntil the 'voltage recorded is a maximum.

In addition to the provision of an aperiodic vibrating relay and special phase adj usting means a further important feat-ure of the present invention in which it ditl'ers 'from prior arrangements is the employment ot a polarized relay instead of a neutral relay. The polarized relay is adapted to give dit ferent indications depending upon whether the alternating current through the track is in phase with the local alternating current or is 1800 out ot phase, and this is ot considerable value for point detection, three position signaling and other cases where a selective indication is required.

The accompanying dra-wings show by Way of example several embodiments of the invention, though naturally additional modifications will readily occur to those versed in the art.

Fig. l shows an arrangement of a double rail track circuit for non-electrilied lines with a standard .neutral direct current relay as track relay.

Figure 2 indicates a. similar arrangement, in which, however, only one rail is insulated, so that the protective arrangements are different.

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Figure 3 shows i tiouhie rail tr:l circuit with iiniiethinee honds tor use with ete-Striiiii lines. this ineiuding :i inoihtieii errunge- :i section section being' isohiteti troni t tions bj.' the insulators 3 i represent. a terr-uiting` eur-re zirrying u pre lure i` r in" und troni tl 'ist current is 'l f Condenser 'T to the tred( rai the other enzi oi S Comprising u rre i which us above inentione iy be of vthe tj' xation lo. 15 this reiey energized n current po snpiiiifi h f; denser T to the truck rrxii' arnizziare 2 :it "quenrs' piu' t'requeney. izzeh tinie :i1-inzitx Contact, u circuit if eonipieteri i'roln ,uur and (3 r the l0 Shiloh in i euse is s ioi'n neutrrii relay. tion oi' armature i) is {piene}v the current or relay l Aroni ieuds und 1 l oeires puises o'j :ferr-ent nim the sa i. direction, It is therefore e111, e i und operates its r1 'niet n'es il und 1Q so :is to close the usuui controlling Circuits for ing sli'steni. 'She non-inductie 13 eonneeti s may io und particularly p :redini-'1 Et Wiil be upA tionship of the able iinportun und ineens is therefore desi current shuii ouh; he ie rent relay during` e Cave Shown general on L tine adjustment eteteo niechani the rectifier S.

1lWhen zi treiiA 2 of the seetioi rectifier S is sh eonies on to the riiiis l r under eonsiderzitron 7 orteii outv in 'the usuari r ner, so that nrrnziture Q cornes to 111 rehiy 1U is reierrsed. @The eoufien'fe iiso serres lto he i" L the e -rrent maken nunnsi zint "when which function Cou :'ipt to become unrelizihie.

'esenti case this eiinrriy c t hap 'i certainty oi operation i indeiie t, ent of exteriui phys! :il eonditions. More over. n'hiie, Luned reeds will not no1-inn` i f vii L to currents o1 other iirequef ure :rpt to he thrown into ifofeei'i tions bj; such currents it .iargfe the orr und zigziin, ,3* sensitireners 111115' he Hnpziireifi.

the pre ont invention. tir'L 1ieourse resrionti eluuiiy Weil to "s et t1. pieney Giiiferent from i it :is the Vireiiiiqr ii 1 unrii" eirenni ironi ene i 'v'iii a-:feidentzii phrase eorre ts inertia und h f the ei'eet or e-istzinee 12j.

nent for eiewtri-I ruil trash' rail l is continuous win t by insulators :auch :is 1;' 1 o. yIhe fe" is non' from power moins if irough trzins'i'n'iner ifi, the seeoiuhiir en# cuit including condenser The reetiiier 22 is in this crise connected throi rondenser and the iinpethui 're 2v2 -which serre to protest the reeitier in eus-e of Contact hetn'ee 1 the traction iii'e *nii anni the iii nsefl itor siicfzrtniiigpurposes. n

to protect the trui iihir Contingency while Piso rent iin i ini;l und phase znilius" rfhe teer-ring current for the is :liso in this n fornier 2S, tri-e zrrung nient oi t 1e vih Contact und the non-inihidtn heini); :is before. Arn'uitu j) und 23() oi the truei( rein); will ngiin control eireiiits :is required in th s nie n miner is with ordinary trick Cireuiting. The ir iingeinent shown in Fig. 2 it xiii he noted proviiied comp ete isolation Yfrom the direc-'t` current traction Circuits.

ln 3 shon'n i inorifiied arrange nient employing double reetiiiezition ut the reeeii'infcY end, th errang; ments beingr otherrfise siniihi to Figs. l o1 The truck rails :ire represented hy Si und 32 und i323 is the reetitier eontroiringl :i xf'ihrzitinr Contact 3G. l'n this instance, however. armature 3G nmhes Contact in euch oi'r its extreme positions and the treek relay comprises two "eli lines -`,riti

coils 37 and 38, shunted respectively by noninductive resistances 39 and 40. Current is supplied at 34 to the primary of the trans former 35 and the secondary is connected to the vibrating contact 36 and to the junction of windings 37 and 38. Hence when the rectifier receives current over the track (supplied as before from the same source as 34) pulses of current are fed alternately to coils 37 and 38. Clearly a pulse is now obtained for each half of the wave and additional security is obtained against the tendeli-y ot the track relay to release between the pulses.

In Fig. 4 is shown an arrangement for electrified lines with a double rail track circuit so that impedance bands 43 and 44 are necessary to isolate the sections for signaling purposes while giving an uninterrupted return for the traction current. Current is supplied from mains 45 to the transformer 46, from the secondary of which it is fed to the rails 41 and 42 by way of the condenser 47. The arrangements at the receiving end include the use of a threeposition track relay, this relay taking up in addition to its neutral position a different operated posi,- tion according as the controlling currents are in phase or 18()o out of phase. The rectifier 4S is similar to that shown in Figs. 1, 2 and 3 and controls a vibrating contact 49.y The three-position relay is preferably constructed with a closed annular core 53 on the two halves of which are located the coils 51 and 52, wound so as to give consequent poles at the junctions. The ring and coils are assumed to be located in a vertical plane. Pivoted axially at the centre of the coil on a pivot 55 is a permanent magnet 54, preferably ot cobalt steel, arranged to occupy a vertical position when no current is fed to the relay. This magnet controls armature 56 so as to close eithercontact 57er 58 when the magnet swings to one side or the` other. Current is supplied from the power mains 45 through the transformer 50 in the same manner as in Figs. 2 and 3, and the relay is again shunted by a non-inductiveresistance 59.

In operation, current is transmitted over the track in the usual manner and operates the armature 49 of the rectifier 48 at the supply frequency. Each time armature 49 engages its left hand contact a circuit is completed from the secondary of the transformer 50 for the coils 51 and 52 in series. Consequent poles are therefore produced, for instance as shown, and the magnet 54 is rotated in a clockwise direction so as to cause armature 56 to engage with contact 57.

If however a reversing switch is provided in the leads supplying the transformer 46 or the transformer 50, for instance as shown at and this switch is operated, the phase y relationship of the two currents controlling the relay is altered by 180. Consequently the pulses of current fed to the coils 51 and 52 are now in the o posite direction, so that poles are developedq in the core 53 opposite to those shown and magnet 54 thus swings in the other direction to close the contact 58.

Thus by means of this arrangement it is possible to use a polarized relay and hence obtain three operated positions while retaining the special advantages incidental to the use of alternating current in this connection.

Vhat I claim is 1. A railway signaling system comprising in combination an insulated section ot' track, a source of alternating current connected to one end of said track, a polarized relay connected to the other end oi" said track, a subw stantially aperiodic vibrating contact inember cont-rolled by said relay, a direct current relay, means for rendering said direct current relay sluggish and nicnas for connecting saidsource oil alternating current, said vibrating contact member and said direct current relay in series so that when said contact member vibrates at the frequency of said alternating current source, uni-directioiial pulses of current are fed to said direct current relay.

2. v A railway signaling system comprising in combination an insulated section of track, a source of alternating current connected to one end of said track, a condenser. in circuit with said alternating current source for determining the phase thereof. a polarized relay connected to the other end of said track, a vibrating contact member controlled by said relay, a direct current relay, means for rendering said relay sluggish and means for connecting said source of alternating current, said vibrating contact member, and said direct current relay in series so that when said Contact member vibrates at the frequency of said source and has the correct phase relation` unidirectional pulses otf current are `lied/to said direct current relay.

3.'A railway 'signaling system comprising in combination an insulated section of track, a source of alternating current connected to one end ot' said track, a polarized relay connected to the other end of said track, a vibrating contact member controlled by said polarized relay, a second polarized relay, means for rendering said second rela sluggish and means for connecting sai( source of alternating current, said vibrating Contact member and said second polarized relay in series, sor that when said contact member vibrates at the frequency of said alternatingcurrent souice uni-directional pulses of current are ted .to said second polarized relay which is theren by operated in one direction or the other i Clie Yiliraiioiis of Said Confed;

one end oi, said traen', a polarized relayv Connected io *elle odrer end of Said track, a 'vibral'iug Contact meiixlier Controlled by said pola ized relay, a Seeend polarized relay, lieans for rendering` Said directA Current relax' Slriggislr and Connecting irre` is independeiit or said lraek for eo eeting rid source ofi aliernatipg Current. said eoiiaet member and said second polarized relayv in series, so that when Said Contact member vibrates at fue rrr" ieacy of said source, mii-directional pulse or errrreni are :fed *so il second po larized relay v," lr opera ed in one dreriion or lie otlie according afs the 'ilirz tionS olf Said eoalgar-l meiiilwr are in pliaSe or i500 out of phase with Said roaring current souree.

S. A railway Signaling ern Comprising iii eorrilillaiioir iii insulare-'d Section or' iravlz. a Source or alreriia'iug current connected lo one end of said track, a polarized rela)v Qonieeied to the oiflier end of said haelt, a

ati-rg contact rneriilier coi'rrr'olled la' Said arized relay, a second polarized rela)v f mg aa armllar core, @aerei/ing t; ou said eore. arranged afs l'o proreoiizfequent p "i ai opposite elidS of a arreter. a `Jrimineni magnet pvoted on eore, con 'i Closed by Said iperated ro eirlier oi? its er:-

j current source. gluig siem eorripr.

allieriialing eurreat i in alare :5oz atri f trad-L a i alghe; allen i lo i ireiii polroiiis, a re lauree eerneeied across polarized relaxl il Source of all Current7 Said vii r meiriber and salie Second polarized gela"y ries.

il. fr railmij; signaling ,sj-,Frein eoiiiiirisingg in eo1nl1iiu-i' air iosalaiied seeioii or" tra-eli, Haring errrreiit eoiiueeied lo Olie end of Said ti reir', a polariz d rela)1 eoiiheeled te die oller end olf #aid raelc` :i blurring Contact laeiiilier C'iiirolled by Said polarized relay. a Seeozid iriyed rel-Ja,

' le sf'laeeoataet lil i siid sonrie or altiens7 a Source Y neced to one end or one eoridew' in circuit v.' il

ng current Yer ee relationslri *eliereo'fi :i r. 1eli-ed to other e.

par forisertion, a Contact eeuu -veted e nee rE :faid dire/et e irrerit relay, means for Connecting sind source. of

a re ra alternating current, said vibrating contact member and said direct current relay in series and contacts controlled by said direct current relay for opening or closing points in the signaling circuits.

11. A railway signaling system comprisingr in combination a pair of track rails, insulators dividing said rails into sections, impedance bonds bridging said insulators, a source of alternating current, a transformer having its primary fed from said source, a condenser, means for connecting tlie secondary of said transformer across said track rails at one end of one of said sections in a circuit including said condenser, a polarized relay connected across said track rails at the other end of said section, a substantially aperiodic vibrating member controlled by said polarized relay, a second polarized relay, a resistance connected across the terminals of said second polarized relay, a second transformer having its primary also fed from said source, means for connecting the secondary of said second transi'ormer, said vibrating contact member and said second polarized relay in series and Contact members connected in the signaling' circuits and closed by said second polarized relay in its operated positions.

Signed by ine at Cheshire, England this 17th day of October 192x ALFRED ERNEST HUDD.

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