TRAININDICATION SYSTEM.
Application filed May 29 1925. Serial No. .

inbefore mentioned and it is presumed that reLerence will be had to said applications.
Referring to the drawing a track section consisting of track rails 6 and'7 is shown set apart by insulated track rail joints 8 .8' 60 8" and 8c. At one end of said track section a track transformer 9 is shown connected to track rails 6 bymeans of track wires 10 and 11 and resistance 12. Transformer 9 is the medium when energized by means of 65 wiles 14 and 15 irons power wires 16 and 17 connected to the source of energy alternator . 18 by which .approptiate current su1ply when a train is not present is transmitted via track rails 6 7 to track wires 19 and 20 70 to winding 23 of reia..y 24. Winding 25 of relay 24 receives energy by means of. wires 26 and 27 from power: wises 16 and 17. At the ends of said track section I slid* inipedarce bonds 13 and 21 connected between 75 track rails 6 and 7. Both bonds have a center tap„connection 13a and 21a respectively which serve as the means whereby track rails 6.m0 7 of adjacent track rail sections are Made electrically continuousfor the return 80 of the propulsion current from track section to track section. Relay 24 is the nieditiim by means o f contact 28 whereby' the' autoinatic working of a block signal system (not shown) by the train is carried into' effect. 85 It will be observed that .I Have not shown ablock signal system and this is because the same is unnecessary to a. proper understanding of this inventionfor the same reason
T have only shown one track ..section—but it 90 will be understood that adjacent track sections will be constituted similar to the track section described herein The track circuit outlined above is the wellknown tworail track circuit as used on electrified railways 95 whether the propulsion current be direct current or alternating current.
Impedance bonds 13 anc consist of a few turns. oa comparatively heavy copper cond.uctor mounted on a magnet:ie circuit and  f•orin a path. of low ohmic resistancebetween track rails 0 and 7. Each bonit is provided with a centre tap connection 13a and 21a resnect 1 elv at which tap points connection is made to the corresponding centre tap. points of the bonds for the adjacent tracksections. The turns are so arranged that when equal  tSties of current flow from each track mail 0 and t of one traclt section via the centre tap to track rails 6 and 7 of an ad
This invention relates to train indication
systems in general and has particular refer
ellce to indicating the progress 0 i railway
trains especially though not exclusively on a railroad which requires that both of the track rails be electrically continuous for the return of the propulsion current but which must be sectionalized to permit and provide for the operation of a. block signaling syste.
0 This present application is a continuation in part: of my pending applications Serial No.  fled March 27 1924 which has natured into Patent Io   dated August 17 1926 and Serial No.  filed
i5 February 11 1925 which has matured into Ida ent 1'0.  23 dated August 17 1926 bot11 'or train indication systems.

In my application Serial No.  I have disclosed a train indication system
22o wherein one of the truck rails o1 a track section it sectionalized by insulated rail joints located at predetermined points to permit the working of a signal s:stem while the other rail is'w untained electrically continuous for the return of the propulsion current. In my
pplication Serial No.  havedisclosed a train indication system as installed in nonsignalled territory vand wherein both track rails are maintained electrically continuous
 for the return o the propulsion current.

In this present applicator I disclose my invention using the principles disclosed in my previously re f erred to applications as installed on a railroad both of the rails of
s: wh icli are sectionalized to permit the working of a signal system lint also made electrically continuous for the return of (h e propulsion current from track section to tries section by means of impedance bends all as hereinafter explained.

The. general objects of this invention are to provide means to iildictit.e the position and proCresso trains on the type of track cireit briefly described above and to carp said
15 indication into effect without moving Parts. Another objectis to provide a means to autozraticallyshift the phase relationof trick circuit currents and without mnoyin parts other than the moving train on said track
5o circuit.

s have provided the accompanying draw
ing to clearly illustrate my invention and to
the extent possible I have. used the same
reference characters il ct catine rn Sias parts
55 as were used in my prior applications hei•e

jacent track rail section no magnetic flux is set up in the magnetic circuit—in other words the magnetic flux set up by current from track rail 6 to the centre tap is neutralized by themagnetic flux set up by current from track rail 7 and vice versa. When however current flows from transformer 9 the centre tap is not involved and the path of current flow in bond 13 is from track
10 rail 0 to track rail 7 or vice versa as will be appreciated and therefore bonds 13 and 21 constitute a path of low ohmic resistance for track circuit operating current from transformer 9. The path of low ohmic re
t5 sistance via bonds 13 and 21 is increased many times by virtue of the magnetic field surrounding bonds 13 and 21 and according to the wellknown laws of induction a comparatively high impedance to the passage of
20 alternating current by the magnetic flux is set up in said magnetic circuit. Impedance bonds 13 and 21 therefore do not constitute a path corresponding to short circuit conditions on the track sections.
25 My present invention consists in inductive ly coupling the indication system of my prior application Serial No.  which has matured into Patent No.  dated August 17  to the track circuit in the
fol
00 lo11 Ino' mariner :—A magnetic circuit 43 hav in i winding 44 Is connected to track wires 10 and 11 by means of wires 45 and 46 and when the track section is not occupied by a train winding 44 receives current fromtrans
35 former 9. The flow of current in winding 1 is such as to produce a magnetic flux immagnetic circuit 43 in Inc relative direction of arrow 51. Mounted on the magnetic circuit 43 I show a girding 47 which is included in
40 a circuit which includes winding 35 of inductive coupling 34 this circuit being com
pleted by the wires 45 49 and 50 and receiving current from transformer 9. The flow of current in winding 47 is such as to produce .I
45 magnetic flux in magnetic circuit 43 in the same relative direction as that produced ln' winding 44—that is in the relative direction of  51. Owing to the fact that current flow in windings 44 and 47 produce a flux in
50 the same direction (when a train is not present on the track section) in magnetic ciicllt 3 win' 4 end 17 mutually build up a magnet ie field in magnetic circuit 43 and di ' retard the flow of current in each other : wind
5 ing 44 is thus prevented under these conditions from forming a low iillnei3ance lath on track section and transformer 9
1 have explained that il'indin' 35 of in
d'•.1[ rive coupling 34 is included in a cir'c'uit
60 which receives current supply from trains
former 9. Inductively coupled to winding 35
! show winding 36 and the current induced
by indino 35 into winding 26 is conducted
via transmission nsmission wires < and 38 to find flows
65 through winding 40 of inductive coupling 39.
Inductively coupled to. winding 1(1 is shown winding.41 and connected thereto is shown indication device (1n this instance. a suitable it 'andescent lamp) 42. " From the foregoing
it l ill i)e clear that :indication device 92. 70 is always energized to a predetermined de
'when transformer 9 is energized and .id e tetermined degree will if or purposes C. Ci !i'ly presenting and des.ci'ibing Inv invellf" vn olnl ' l)e considered to be insufficient 75 to cause illumination of indication. device lamp 4.2 ..when "the track .section is not occupie 1 by a gain.
When €t.ti lin enters: the track section by passing insulated joints 8" and 8º ..a.n additional i)ath o :f current flow from transformer 9 is provided by virtue of the train car wheel. in coo act w1thncrack rails 6 and 7 forming a shunt on transformer 9 as will be ' a ppreciated 1d the act of forming :a shunt. on transformer 9 a shunt is also former! on winding 44 but the shunt on winding 44 is more complete than the effect of said.' shunt
oil a •ans. ornrer 9 (because resistance 12 is included in the. shunt on transformer 9) and the. current: supply from transformer 9 to said winding 44 is reduced As a. result of
the redl ct]nn In current flow in winding 44 the magnetic'
agnetic flux in magnetic circuit 43 is reduced.. upon the. reduction. in lux increased current flows. from transfoliner 9 through Winding 47 and tends to restore the. lux .. .said. magnetic circuit 43. C iint• to the fact that ivindino 35 of induc f ive coupling 34 is included in the circuit which includes winding. 47 increased current is induced from winding 35 to winding 36 and transinutted via wires 37 and. 38 and causes increased current supply to flow to in. dicntion device lamp 42 and this results in ins said lamp Tieing illuminatedand is accepted
as an indication. as to the. position of the train at the :(normal) entrance cld of the track section.
As th.e train pa eceeds. through the track Ito. section in the driedt.ion of the: arrow its movement will ae. evidenced at i 1clii itioil device. lamp 42b.  Increased bri.lliancv. Said increased bi Milan( is I}ioi ht about by Aire the of the to t that. the car. wheel inol elnent  along track rails 6 and 7 gradually .cuts tau the Airfield—rail .>1 C11cC. included air the. cat' wheel shunt. o Winding 44 thus response rely making said. Anlit More effective: 1 c'cSnal bigas said ..11 •1t. beaites more. effective. less ti" em}it from.. tlansfornlei' 9 flows vial winflin{  4'S' ivliinh i'esiil1sine lessen d fillx density i1 core 43. and thereafter increased current floras from tr"a:Ils'l71'r? ei' 9 via. 'windings s t7. end ?: with attendant increased induced c.urrent 'supply to n1') 4:2 all as ale' elalicf ?i'e explained.
Impedance bond 13 in. addition to provicl.ing means for the return of the. propulsion current .from track section to track section
80 8.5 90 95
  
on electrified railroads as hereinbefore described also provides r meansto limit the variation in the value of current supplied .to indication device lamp 42 as the train pro
5 ceeds through the track section— other Words bond 13 acts as a ballast element or permanent shunt on winding 44. That bond 13 should limit the variation in current supplied to the indication device lamp 12 as the
l0 trawl proceeds through the track section will be clear from the following:—Consider first that bond 13 is not present that thecarwheel shunt is of negligible resistance and that the resistance of each track rail is one ohm—now
15 with the carwheel shunt at the left end of the track section the shunt on wmdino 44 is two ohms because of the two ohms resistance of the included track rails—when the carwheel shunt has proceeded one fourth of the distance
20 through the section the value of the shunt on winding 44 will be one and onehalf ohms lie cause of the resistance of the track rails then included in the shuntsimilarly it will be clear that the value of the carwheel shunt on
25 winding 44 willbe one ohm with the carwheel shunt at the halfway point onehalf ohm when the carwheel shunt is at the threequar
ter point and so on until the carwheel shunt reaches the right end of the track section
30 when the shunt on winding 44 can be con siderecl to be a short circuit in other words it may be expressed that the variation as the car proceeds through the track section follows a straight line law. Now consider that
35 bond 13 of say two ohms resistance is connected in multiple as shown and witli values of two ohms rail resistance as beforein this case with the carwheel shunt of negligible resistance at the left end of the track section
40 the value of the carwheel shunt on winding 44 Will be the result of two ohms rail resistance in multiple with two ohms bond 13 resistance which is one ohm when the car
wheel shunt reaches the quarter way mark
the value of the carwheel shunt on winding
44 will obviously be the result of one and one
half ohms rail resistance in multiple With
two ohms bond 13 resistance which is 67
ohm continuing similarly it will be evident
50 that at the half way point the value of the shunt on wincing 44 will be twothirds ohm at the threequarter way point the value of the shunt on winding 44 will be twofifths ohm and so on until the carwheel reaches
55 the right end of the track section when the shunt on winding 44 can be considered to be a shortcircuit in other words it may be expressed that the variation follows a curved line law with an increasing rate of
60 change.
Comparing the case mTith and without bond
13 we find that the variation in value
while % for the track section in each
case is differently distributed—a uniform
55 variation obtaining throughout the section
without the bond: 13 and a nonuniform variation with the bond 13 which acts to bunch the variation—the rate being (treater as the carwheel shunt approaches the bond and since the amount of current flowing 70 through winding 47 for variably influencing indication device lamp 42 depends on the variation of carwheel shunt value on windink 44 it will be clear that bond 13 acts as a ballast element to characteristically vary 75 the current supplied to said indication device lamp 42 in fact a ballast element may be connected at any point between track rails 6 and 7 or between wires 10 and 11 or between wires45 and 46 for suitably variably 80 affecting the current supply to indication device 42 as the carwheel shunt proceeds through the track section but I wish it to be understood that said ballast element in the form and location of bond 13 or elsewhere may be used or omitted without departing from the spirit and scope of my invention. Obviously the values used in the above example are simply illustrative and are given only for the purpose of clearly describing the ballast effect of bond 13.
Resistance 12 is an element included in the energy supply circuit of the wellknown A. C. track circuit to prevent an excessive flow of current from transformer 9 when the car wheel shunt is on the track rails at the point where said transformer 9 is connected to the track rails and since said resistance acts to limit the flow of current from said transformer 9 to said track rails and car wheel shunt transformer 9 immediately becomes available as a source of energy supply for the train indication system. Said resist
ance 12 also performs the function of limit
ing the flow of current induced into wind l05 mg 44 by winding 47 (under the conditions hereinbefore explained) through transformer 9 and winding 47 and thus transformer 9 is limited in value as a path for said induced current and therefore has less 1 0 effect on the indication system after said induced current begins to flow from winding 44.
IIereinbeforefor the purpose of clearly describing my invention only I have explained i 15 that the indication device lamp 42 though aimgays energized did not receive enough energy to even slightly illuminate said lamp when said track section was unoccupied and that as said train entered said track section
0
said lamp would be illuminated and with re sponsive increase in brilliancy as the train proceeded through said track section but I desire it to be understood that said lamp may be nominally partially lighted when thetrack section is unoccupied and then increase in brilliancy in synchronism with the appearance and progress of the train through the track section.
I direct particular attention to .the fact
40
s5

:i3 „).
4
 
type 'a hiC'il employ ' ir[ipcnin1 e bonds hecause :such track circuits ectllire a ctitlpara lyely i 'h current iaipni nhen the tciv1 seetlon rS not .occupied and Of iz' a scacll rnclease in.correct'input can be economically l) nilit 70. teal: When fhe track secfinn is occupied. The foregoing we rra tt s the st a t er cut. Oat this
the regularcurrent suppl. .impressed on the trek 1º'ls 'or track c lcuit relay ope ation. 75 ?have.. hereinl) fore.. ponted 01 i Ih it.Ene cmnrent induced from winding a ! Into w Ind—. rri 14. tinder the conditions of t eck ::'Cllr shunt is displaced ire irm' phase net iei1 .to that initially flowing. in 1 Ili 1!i7 i ( anal tli t part of stied rile need c :t lows via ran former 9. Part o3 air?  ldiiced cnreat also flows.. in the circuit incur kin 'a ind ngs 4i and .35wit11 the current from.. t ransformer".9 and according to cm 'e'r inow ii d ccli"lC1l Ian's. :3 two currentsdisplaced in tulle. phase relation combine to produce a<.cnrrent having a ::ante shape possessed by neither ol 'liftlly find as the resultant ame is a.. response: to. the changed :conditions bronght about by .the p r esence rend:n ovemo' t of. a train On flu ritCk section producing a slhcrt 0C va ions vt Ues Oi Sald indt'.1 ' to 'J''rn ahoii aid
phase displaced current—then the statement
is warranted that the current transmitted to nr the indication device is synchrorroiisl'r .Chars.. ecter'istie of the rrinyen)ent'of said train. on Said. track section.
Tt is clearly obvious that various types .of alternating .current :.rack ci rcuits of the. ins single and double rail type .thoiher fort.use. on steamrailroads or on electrified' roads with either alternating current or direct cul'lent pr'opulaon may. be emmloyed with my invention by m king the obvious appropri
at' orange. Well khan pn tn. one or'.inc cis i'
killed in t.fis art. and de.ire. to have it
understood therefore the) t i do not lilui'I my
self to. the arrarigenlent anti nstretio .
which J have shown an 1 dcse ibedº.s..i is. tio merely..illustiat' e ancl —doesnot n h)aist:the varioiS en'bodirnents and forms coins very clearly within the breadth :and seal}c 0 the. broad priirciples a 7(lerl i 7g }1y i1 cation.
i.TS.<<'iilo retie' dcsCi.iiled piy.p idin T .
chi'?11 and ti 'Sire to s i ( i?tt icttC. )dti it .
1. In a. train ill ]t(.t.i. n en' a':if3('lc t'.ii'
chit  il('ln i i t.a son t c () plural do
1 f.: imptalons .rat' para.
With le.tro1
d diCttlOn r?'C 7
it . .ja ch is co : le ~.
:tin Of ands . her tile. rn 'e. ni «1d 1
at Ic circuit.
n .al a n' .Lein t 3 tt
el1'. 7lt including 0.0 cue''':. a con
'1 olti)Jiel's('i'twoV .il" 71t s£0fl rttee ':.e
relation. to .each. other o : .of id i nl(tings.
i reefed in her hel with se.idl tr acs circuit
that whereas illy Patents Nos.  and 15' function on the basis of change in the rate of current flow directly from transformer 9 through the car wheel shunt this
5 invention functions on the basis of the car wheel shunt forming a short circuit on winding 44 as will be clearly evident from it consideration of the fact that my invention will
functions properly ilei encl nt of
function to show position and movement of 10 the train even though no current is supplied
to the track rails directly by transformer 9.
That my indication system will unction to
show position and movement of a train on the
track circuit even though no current issup15 plied to the track rails directly by trans
former 9 will be clear from a consideration of
the fact hereinbefore set forth that the
train forms a shunt on winding 44 which
shunt includes variable amounts of tra It y0 rail resistance according as the sh sin
(trail) occupies one position 01 'notheis on
the track circuit. Obviously. the gain shunt
is more effective on winding•44 than ontrans
former 9 (because of resistance 12 being il 25 eluded in the train shunt effect on trans
former 9) Resistance 12 therefore pro
vides that in every instance for the ease ii
lustrated the potential difference betvreen
wires 10 and 11 on the track l side of re30 sistance 12 will be lower than on transformer
9 side of resistance 12 and progressively low
er as the train shunt moves in the ci.rectiOn
of the arrow on the track circuit. It isap
parent that resistance 12 is not essential to 35 the shunt on winding 44. but resistance 12 is
essential to prevent short circuit on tiaras
former 9 by the train shunt and is also neces
sary to provide a sufficient current flow to provide for track relay 24 operation. Now in the event that resistance 12 is broken or removed the current supply directly from transformer 9 to the track rails and tileaSOciatedpotential difference across winding 44 hereinbefore referred to will cease but according to the wellknown law of mutual in Auction Winding 44 will become a secondary winding to winding 4r
c In this case winding 44 becomes a source. of current supply to the track rails which tack rills are '.en included in series with said winding 44 The track rail resistance at any tie le ncluded in cries with winding• 44 determines the impedance of winding 47 alma therefore the rate of current flow to win(i to 35 of inane five coupling 34. The progress of the tr tine 'n the direction of the arrow. on the track
rails acts to include progressively less n:a
rail resistance in the circuit with winding
44. thus lowering the impedance of winding 00 ( and whereby synchronously n1or C' tee t
flows to winding 35 of coupling 31. eventual
1' to be reflected in the indication deice 3
as hereinbefore described. This feature of
functioning by virtue of shortcircuiting is cs of particular value on track circuits of the
invention
40 45 50 0i
so

and the other winding connected to said source and an Indicationdevice included in the circuit with one of said windings said device synchronously indicating the presence and movement of a train on said track circuit.
3. In a train indication system a track circuit including a source of energy a circuit including a winding and an indication device receiving current Troll). said source
10 and a winding in inductive relation to said first mentioned winding and capable at times of receiving current from said source and at times of transmitting current to said source the change between times being effected hy
15 a train on said track circuit the second mentioned wording connected in parallel with said track circuit.
4. In a train indication system a track circuit including a source of energy ii resist
20 mice connected in series in said enei y supply to said track circuit two windings in inductive relation to each other and connected to said source and indication means included in the circuit with one of said wind
25 ings the other of said windings being connected in parallel with said track circuit said means synchronously indicating the presence and movement of a train on said track circuit.
30 1j. In a train indication system a track circuit including asource of energy two windings in inductive relation to each other and connected to said track circuit both of said windings at times carrying currents in the
35 sane time phase relation one of said windings at times carrying current induced therein by the other of said windings and an inchcation device responsive to increased current flow in one of said windings said increased
40 current flow and the change between said times being effected by a carwheel shunt on said track circuit.
6. In a train indication system a tiacl: circuit including a source of energy two
45 windings in inductive relation to each other and connected to said source lid windings at times mutually acting to retard the flow of current in eachother and at times 'mutually ::acting to increase the flow of cm rent it each
so other and an indication crevice responsive to said currents included in the circuit with one of said windings the change between said. times being effected by a carwheel shunt on said track circuit one of said winding's con
55 nected in parallel with said track circuit.
7. In a train indication system a track cir cult including a source of energytwo windings inductive relation to each other and connected to said source said windings at
60 times mutually assisting to retard the flow of c.nrrent in each other and it times mutually assisting to increase the flow of current in each other the change between said retard effect and said increase effect being initiated
65 by a car wheel shunt on said track circuitand a device responsive to indicate said change one of said windings being connected in parallel with said track circuit.
3. In a train indication system a track cir cult including a source of energy a resist 70 twee connected in said energy supply to said track circuit a winding and an indication device connected inseries to said source and a winding in inductive relation to the first mentioned winding the second mentioned 75 winding connected in multiple with the track rail portion of said track circuit and adapted to be shunted by acaron said track circuit said device synchronously indicating the presence and movement of a train on said. Rt' track circuit.
9. Ina train indication system a 'rani cir cuitincluding a source of energy a winding and an indication device connected in series and at tinges receiving variable quantities of Ra current from said source and a winding in inductive relation to the first mentioned winding and at times acting to oppose current flow in the first mentioned .winding the second menticned winding connected to said g0 track circuit and adapted to be shunted by car wheels on said track circuit said car wheels influencing the current flow to said indication device said device synchronously indicating the presence and movement of a r• train on said track circuit.
10. In a train indication system a track circuit including a source of energy a windmg and an indication device receiving current from said source and a winding in inductive relation to the first mentioned winding and capable at times of modifying the characieristic flow of current to said indication device both windings adapted to be shunted by a train on said track circuit to modify said 1(15 characteristic current flow.
11. In a train indication system a track ci r cult including a source cfc her. gy and adapted to be shunted by rs train a winding and an indication device receiving current from said  source and a winding in inductive relation to the first mentioned Winding and adapted to be shunted by said train said. train shunt haying various values of shunt eecton said second mentioned winding dependent upon 1 r5 the position of said train on said track cirehit said indication device synchronously responsive to variations in energy flow in said track circuit due to train movement on said track circuit.
12. In a train controlled signal system a track circuit incliucliug a source of energy a track relay foie cons' ogling: a block signal sysMein connected to said track circuit and receiving operating current from said source when  said track circuit is not occupied by a train a train indication device inductively coupled to a circuit whicl is connected in parallel to said track circuit said device operative to indicate the position and movement of a train