US1602080A - Railway-traffic-controlling apparatus - Google Patents

Description

Oct. 5 ,1926. l;602,080

R. A. M CANN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed August 6. 1923 2 Sheets-Sheet l INVENTORZ ,A Q; ATTORNEY Oct. 5 1926. 1;602,080

R. A. M CANN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed August 6. 192:5 I 2 Sheets-Sheet 2 INVENTOR.

N BY 0.- 2M

Mi ATTORNEY Patented Oct. 5, 1926.

UNITED STATES I 1,602,086 PATENT OFFICE.

RGNALD A. MOOANN, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL CQMPANY. F SVVIS 6F PENNSYLVANIA.

EVALE, PENNSYLVANIA, A CORPORATION RAILWAY TRAFFIC-CONTROLLING APPARATUS.

Application filed August 6,

My invention relates to railway traflic controlling apparatus, and particularly to apparatus of the type comprising train carried governing mechanism controlled by en ergy received from the trackway. More particularly, my invention relates to the traekway portion of such apparatus.

1 will describe one form of railway traffic controlling apparatus embodying my lnvention, and will then point out the novel features thereof in claims.

1n the accompanying and 1 when placed end to end in the order named form a diagrammatic view showing one form and arrangementof railway traffic controlling apparatus embodying my inven tion.

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

Referring to the drawings, the reference characters 1 and 1 designate the track rails of a single track railway over which trafiic normally moves in bothllirections. The portion of track shown in the drawing is provided with two passing sidings F and Ff, located at the left and right hand extremities, respectively, of the stretch. but only one of which, F is shown entire. For purposes of convenience of description I shall hereinafter term that portion of track which lies between the two passing sidings F and F a block, it being understood that by combining the required number of such blocks with the required number of interposed passing sidings F, and F, etc., a complete system of any desired length may be constructed. The track rails 1 and 1 of the bloc: shown in the drawings are divided, by means of insulated joints 2 into a plurality of consecutive track sections A-B, BC and CD, it being understood that any reasonable number of such sections may occur in a single block.

Traffic from left to right over the stretch of track shown in the drawing is controlled by three roadside signals S 5 and S which are located at points A, D and E, respectively. In similar fashion traffic from right to left over this track is controlled by three other signals 8, S and S located at points E, D and A, respectively.

As shown in the drawings, each of the signals S S S S S and S is a colored light signal, and each is provided with three dra\ 'ings, Figs. 1

1923. Serial No. 655,986.

signal lamps 4:, 5 and 6, adapted to project. when energized, a beam of red light, yellow light, or green light, respectively, and thus display a stop, caution or proceed indication in accordance with common practice.

Each end of each section is provided with a source of track circuit current such as the secondary 7 of a track transformer designated by the reference character '1 with an exponent corresponding to the location. Each such transformer secondary is constantly connected with the track rails of its associated section and the primary 8 of such transformer is at times supplied with alternating current by means which will be de scribed in detail hereinafter. Interposed be tween one rail 1 and the secondary winding 7 of each transformer T is an impedance 9, one function of which is to limit the output of the transformer when its terminals are short circuited by the wheels and axles of a passing train.

Each section is provided with two track relays, one located at each end thereof and designated by the reference character R with an exponent corresponding to the location. Each such reiay, comprises a track winding 15. and a second winding 10 which is constantly supplied with alternating current from a suitable source. For example, referring particularly to relay R winding 10 is provided with a circuit which passes from the secondary of line transformer H through wire 11, winding 10 of relay R and wires 12, 13 and 1d back to transformer H he primary of line transformer H" is constantly supplied with alternating current from an alternator 0 over line wires 3 and 3 A similar line transformer is locat-ed adjacent the juncture of each two track sections and is designatedby the reference character H with an. exponent corresponding to the location.

Associated with each track relay Risa line relay designated by the reference character W with an exponent corresponding to the location. Referring particularly to line relay this relay is provided with a circuit which passes from the secondary of line transformer H through wires 11 and 16, front contact 17 of relay W wires 18 and 19,'front contact 20 of track relay R wire 21, bacl; contact22 of a stick relay K wire 23, front contact 2a of relay R wire 25, winding of relay VP, and wires 26, 27, 28, 29 and 14 back to transformer H It is plain that this circuit is closed only when relays W R and are energized and auxiliary relay K is de-energized. The circuit just traced is provided with a branch which passes from wire 11, through wire 30, front contact 31 of auxiliary relay K and Wire 32 back to wire 19 as before. It folloWs that when relay K is energized the closing of its front contact 31 removes the relay from the control of relay Vi. The control of relay is exactly similar to that of relay VV Relays W and W are provided with circuits similar to those just traced for relay W except that the line transformer is connected directly with the front contact of the track relay adjacent the remote end of the associated section thus omitting the line relay il and one of the auxiliary relays K from the circuit as will be apparent from the drawings.

Relays lV Vi W W", and VJ" are of the polarized three position type and are each provided with two windings 83 and 34, one of which is constantly connected, as usual, with a source of alternating current. Referring particularly to relay V7 winding 33 of this relay is provided with a circuit which passes from transformer H through wires 39 and 38, winding of relay 7 and wires 37, 36 and back to transformer H The relay is arranged to be responsive to reversals of the relative polarity of the current supplied to winding 34- which is provided with a circuit passing from the secondary of an auxiliary transformer M whose primary is constantly supplied with alternating current over wires le and 11 from transformer H through Wire 40, front contact 41 of, relay W wire 42, front contact 43 of relay 3V wire a l, back contact so of auxiliary relay K wire 46, front contact 4-7 of track R wire 48, front contact 49 of track relay R wire 50, winding of relay wires 37, 36, 51 and 52, front contact 53 of relay W" and wire 54 back to transformer M This circuit is closed only when relays R R and l/V are energ zed and relay K is de-energized under which conditions the polarity of the current supplied to relay W is of what I shall term normal relative polarity, and the contact fingers on relay VV are swung to thevright. ll hen relay W is {ls-energized, however, as by a train moving from right to left in section BC, relay K as will appear hereinafter, is energized and the circuit for winding of relay 5V passes from transformer M through wire 40, back contact 53 of re- VW, wires 36 and 37, winding of relay ll, wire 50, front contact 49 of track relay R wire-s 8, front contact l? of relay 1%, wire :6, front Contact 4 5 of relay K wires 55 and 56, back contact 41 of relay W and wire 5% back to transformer M This circuit is closed only when relays R ll and K are energized and relay is tie-energized, under which conditions relay Tu ll is supplied with current of what I shall term reverse relative polarity and the contact fin ers on this relay will be swung toward the left. Line relay W located at point r and relay W" located at point- E are controlled by circuits similar to those just traced for line relay ll.

Associated with each of the line relays ll, 'W W", V ll and W is a repeater relay designated by the reference character G with an exponent corresponding to the location. Each of the repeater relays G is controlled by its associated line relay as follows: Referring for'exaniple to repeater relay located at point D, this relay is pro i d with a circuit which passes from trains merL whose primary is constantly supplied with alternating current from transl though wire 57, normal or reverse contact 58 of relay ll, winding of 11b relay G wires G0 and 68, back contact 61 of track relay R and wires 62 and 63 back to transformer L This circuit is closed only when relay R is tie-energized but it will be noticed that back contact 67 of track relay R is connected in multiple with back contact 61 of track relay 3 and that the circuit may therefore be closed by de-energization of relay R Each of the remaining repeater relays G is provided with a 31m ircuit similar to that just traced for relay G in addition, one terminal of each of the relays G G G and G is connected to a common wire 65. Eiimilarly, relays G and (i are connected by means of wire with two relays at the left hand end of siding F and not shown in the drawing. The resultof such connection is that relays G G G" and G are normally tie-energized but that when a train enters section CD, D-ll, or the section to the right of E, these relays will be immediately energized, provided the associated relays V are energized. The operation of the repeater relays G associated with siding F similar in all respects to 7 that described for the relays associated with siding F Line relay ll is controlled by repeater relay G in the following fashion: An al ternating electro-motive force of one relative V polarity or the other is connected with armatures 79 and 81 of relayG from transformer M by means of wires and 82, depending on whether relay, G is energized or t le-ener ized. Relay W is then provided 1135 with a circuit which passes from armature of relay G", through wires 83 and 63, winding ofrela-y Vi 7,'wire 770, front contact 71 of track relay R wire 72, back contact 73 of relay 32, wirefie, front "contact of track relay R wire 76, front contact 77 of track relay R andwire 78 back to armature 79 of relay G It follows that when track relays R 3 and R are energized and relay K is de-energized, relay al will be energized in one direction or the other depending on whether or not relay 9 is energized. Line relays W and W are provided with circuits similar in all respects to those just traced for line relay The auxiliary or stick relay K associated with track relay R is provided with a pickup circuit which passes from transformer l-l through wires 11 and 8 1, back contact of relay i 5 wire 86, back contact 87 of track relay h, wire 88, back contac 89 of track relay B wire 90, front contact 91 of relay Vi, wire 92, winding of relay K", and wires 93, 9%, and 1 1 back to transformer H The stick relay K will be energized therefore as a train, moving from right to left, enters section 13-0 at point C. The energizing of this relay closes a retaining or stick circuit which passes from transformer H through wires 11 end 95, back contact 96 of relay R wire 97, frontcontact 98 of relay K wire 99, winding of relay K and thence to'wire 93 and back to transformer H as before. This pick up circuit is closed only when relay K is energized and relay R is de-energized and serves to maintain K in its energized condition as long as any part of section BC is occupied by a train. Stick relays K, K and K are controlled over circuits sim lar to those just described for relay K Auxiliary relay K" is included in a circuit which passes from transformer H through wires 95 and 96, back contact 97 of track relay R", wires 98 and 99, front ct 100 of repeater relay G wire 101, winding of relay K and wires 102, 103 and 10% back to transformer HE. The circuit just traced is also provided with a branch which commences at wire 98 and leads through wire 10?, front contact 106 of relay K", and wire 105, back to the winding of relay K. This branch comprises the stick circuit and the circuit first traced comprises the pickup circuit so that the relay is normally de-energized but is picked up by the entrance into section DE of a tra moving from right to left, and this one zation continues as long as the train :"1 occupies the block. A stick relay K is cor olled by circuits similar in all respects just traced for relay K Yes as a repeater for relay K and controlled over a circuit which commences at transformer, H and leads lrrough wires 108 and 109, front contact 110 or relay 3?, wire 111, back contact 24 of clay R wire 23, back contact 22 of A wire QL'back contactQO of relay sire 112, winding of relay'l", and wires 113, 9 1, 141- and 29, back to transformer H It follows, that if relays E R and K ar de-energized, relay P operates as a repeater for relay K Similar repea er relays P P, P and P are controlled over analogous circuits.

As shown in the drawing one end of each section is provided with a source of current. leferring particularly to section BC, transformer T has its secondary 7 constantly connected with the rails adjacent the left hand end of this section and its primar \i-inding 8 is provided with a circuit which passes from transformer H through wires 108 and 11a, back contact of relay K wire 116, primary winding 8 of transformer T and wires?! and 28 back to transformer H It is evident therefore that track circuitcurrent is supplied to section B@ from transformer T only wnen relay hi is deenergized. The track transformers T T, T and T are controlled in exactly the same manner as track transformer T7. Referring again to section B-C a second track transformer T is located at the right hand end of this section and is provided with a circuit which passes from transformer H through wires 11 and 117, front contact 118 of relay P wire 119, primary winding 8 of track transformer T ant wires 9e and 14 back to transformer H Since relay P is energized only when relay K is energized, it follows that track circuit current is supplied to section by transformer T only when relay K is energized. Transformers T T T and T are controlled over circuits similar to the one described for transformer T The track winding 1 ll, F

,7 o of each track relay 4 n- R and R is constantly connected with the rails adjacent one end of its associated section. Referring particularly to section BC, an impedance 117 is interposed between one rail 1 of the section and winding 15 of the relay R but are provided for at times shunting this impedance. Thus a circuit is provided which passes from one side of impedance 117, through wire 119, front contact 120 of relay K and wire 118 back to the other side of impedance 117. The purpose of this impedance is to limit the current through the relay when the track transformer the same end of the section, as T is energized. The shunt circuit just traced is carried over a front contact on relay K and we, have just found that when relay is? is energ" T ed, track transformer i is deenergised and track transformer T is energized; therefore the, impedance 117 is short circuited only when the track circuit is being fed from the opposite end of the section, in which case the current leakage through the section reduces the voltage at the relay R to such value that it can safely be applied to the relay without series 1111- iii) pedance. The remaining end of each section is provided with a track relay which is at times entirely disconnected from the track rails. Thus the winding 15 of tracl: relay B is included in a circuit which passes from one rail 1 of the section B C, through wire 119, winding 15 of track relay Rd, wire 120, back contact 121 of relay P and wire back to track rail 1 of section BC. It is clear that the energization of relay P will completely disconnect relay R from section l3'@ and that this connection will not he re-established till relay P again becomes de-energizcd. Circuits are provided for lays R R R and R similar to that just described for controlling relay B.

Each of the signals S is controlled by the ociated relays l? and as follows: liciciring particul: y or red lamp 1- of o s signal is provided with circuit wnich passes from the secondary of a lighting transformer J through wire 123, back contact 125 of relay G wire 125, lamp 41- of signal S and wire 127, back to transformer J This circuit is closed only when relay G is deenergized, which is the normal condition of the apparatus corresponding to the unoccupied condition of 'he track, and in, which case lamp 1 is lighted and signal S displays a stop indication. The primary of transformer J is constantly supplied with alternating current from the secondary of transformer H The caution circuit for signal S pas es from transformer J through wire 123, front contact 125 of relay G wire 128, reverse contact 129 of relay 1V wire 130, lamp of signal S and wire 127 back to transformer J This circuit is closed only when relay G is energized and relay V1 is energized by current of reverse relative polarity, under which conrition lamp 5 is lighted and signal Q2 displays a caution signal. The proceed circuit th s signal passes from transformer J through wire 123, front contact 125 of relay G wire 128, normal contact 129 of relay W wire 131, lamp 6 of signal S and wire 12'? back to transformer J This circuit is closed only when relay G is energ zed and relay Vi is energized by current of normal relative polarity under which condition lamp 6 is lighted and signal S displays a proceed indication.

Means are also provided for each section for supplying to the rails in parallel a current which I shall hereafter term a local current For this purpose I connect an impedance 132 across the rails adjacent the left hand end of each section, a similar impedance 133 adjacent the right hand end of each section, and two similar impedances 134: and 135 at intermediate points in each section.

Traflie movingfrom right to left through section BZG is controlled by local current to signal S the stop supplied to the rails by a double secondary local transformer N whose primary is constantly supplied with alternating current from transformer H over wires 28 and 108. A, local circuit for this section passes from secondary 13-6 of transformer N through wire 138, front contact 139 of relay il wires 1. and 14-1 to impedance 132 of section BC, thence through both rails of the section in parallel to impedance 133, then rough wire 142, back Contact 143 of re ay wire 1&4, hack contact 1&5 of relay K wire 1%, front contact 1 17 of relay it, and wire 14:3, hacl; to transformer N This circuit is closed only when relays K and P are tie-energized antL relay V7 is energizec, mid-er which conditions the rails of section C are supplied with alternat ng local current of what I shall term normal relative polarity. lf, however, section Al5 is occupied by a train, relay W is deenergized and the local circuit then passes from secondary 136 of local transformer N through wire 133 back contact 139 of relay ll, wire baci; contact 1 of relay K wire 1%, ch contact 1-1-3 of relay P wire 142, impedance 133 in section B C, through both "ails of the section in parallel to impedance 13 1, thence by wire 150, back contact 1 17 and wire 14:3, baclr. to secondary 136 of transformer N This circuit is closed only when relays K P and V1 are all tie-energized, under wnich condit ons the rails of section l3C are supplied with local current of what 1 shall term reverse relative polarity bet-ween impedances 133 and 13d, but with no local current between impedances 132 and 13 1-.

Traliic moving from right toleft through section (3-4) issupplied with local current over circuits similar to those just traced with the single exception that the circuit for supplying local current of reverse relative polarity to the rails of section CT) between impedances'13s'l and 133 is carried over a'front contact 170 of auxiliary relay Kt. The purpose of this Contact will be apparent as the description proceeds.

Traffic from left to right tnrough sections BC and C-D is controlled by local circuits similar to those t traced for governing traffic from right to left through section B C. V 2

Traffic from eft to right through section CD is controlled by a local circuit which passes from secondary 13'? of local transformer I through wire 1%, front contact 151 of relay G wire 152, normal contact 153 of relay T 1 wires 15%, 155 and 156, impedance 133 in section CD, through both rails of the section in parallel to impedance 132, thence through'wire 157, front contact 153 of relay 1Z wire 159, front contact 160 of relay wire 161, normal con- 1. tact 132 of relay Vi, wire 163, front contact 16a of relay 6 and win; 165 ba k to winding 137 of local transformer N This circuit is closed only when relay V is energized in the normal direction and relays K P and G are all energized, under which condition local current of n rmal relative polarity is supplied to the rails of section CD between impedances 132 and 133. when relay V? is energized by current of reverse relative polarity the reversal of contact armatures- 153 and 162 connects wire 155 to wire 163 and wire 161'to wire 152, thus reversing the relative polarity of the local current supplied to section C-D. If relay V7 is de-energized due to traffic conditions in advance such as the presence of a train in section D.E or the section to the right of E, relay G" will also be de-energized and the local circuit for this section then starts with secondary 137 and leads through wire 1%, back contact 151, of relay G wires 166 and 161, front contact 160 of relay P wire 159, front contact 158 of relay K wire 157, impedance 182 in section CD, thence through both rails of the section in parallel to impedance 135, then by wires 167, back contact 164 of relay G and wire 165, back to secondary 137 of local transformer H This circuit is closed only when relays K and P are energized and relay G is deenergized, under which condition the rails of section CD are supplied with local current of reverse relative polarity between impedance 132 and7135, but with no local current from impedance 135 to impedance 133.

Traffic moving from right to left through section B and the section to the right of E is governed by local circuits similar to those just described for traffic from left to right through section CD. v

The local circuits for section DE and the section to the left of A are identical with those already traced for section BC, with the exception that the pole changing or reversing of the relative polarity of the 10- cal current is accompli hed here by means of relay G whereas in section BC this reversal is controlled by the line relay V7.

Before explaining the operation of the system as a whole it should be pointed out that the trackway apparatus herein disclosed is suitable for co-operation with train-carried governing means in the following manner: FJhen the train is on a portion of track which is supplied with track circuit current and local current of normal r lative polarity, the governing mechanism allows the train to proceed at any rat-e not in excess of a high speed as 65 miles per hour; if the train occupies a stretch of track which is supplied with track circuit current and local current, the relative polarity of either of which currents is reversed, the governing mechanism prevents the train from proceeding at speeds in excess of an intermediate speed, such as 35 miles per hour; and if the train enters a stretch of track to which the supply of either local or track circuit current is for any reason discontinued, the governing mechanism imposes a low speed limitation upon the train whereby the train is prevented from eX- ceeding some low speed as 15 miles per hour.

In at least one form of train governing apparatus suggested for this purpose the governing mechanism is controlled by the current or currents in the track rails through the medium of receiving appliances carried on the front of the locomotive. It is evident that with apparatus of this character the source of track circuit current must at all times be connected with the rails in advance of the. train or the wheels and axles of the train will shunt the track circuit current away from the receiving appaatus and impose the low speed limitation. The track transformers are so arranged, as will be seen hereinafter, that all track circuits are fed by transformers connected in advance of a train, irrespective of the direction of traffic.

As shown in the drawing, the parts all occupy the posit-ion corresponding to normal condition, that is, the entire stretch of track is unocci pied and all the signals S display a. stop indication. I will now as sume that a train moving fromright to left enters the stretch of track shown in the drawing. The presence of this train in the portion of track to the right of E has deenergized l/V" so that when the train enters the section immediately to the right of E, thus cle energizing the track relays associated with this section, the closing of back contact 71 of relay B does not energize relay G but does energize relays G and G vRelay G is not energized because its circuit is opened by the de-energization of relay Vi which resulted from the opening of the front contacts of relay R The closing of the front contact relays G and G closes the circuits for lamps 6 in signals S and S", which signals therefore display proceed indications to the train.

As the train enters section D-E the closing of a back contact of relay R completes the circuit for relay K which thereu on becomes energized. The circuit is tien complete for relay P since relay R is also de-energized, and relay P therefore picks up. The train is now supplied with track circuit current from transformer T transformer T is de-energized, and the shunt circuit around impedance 117 at relay R is short circuited and local current of normal relative polarity is supplied to the rails of the section from transformer N over the front contacts of relay G The train is therefore allowed to move at high speed through section D-E.

section CD is occupied by another train, however, relay W will be de-enerized, relay G will accordingly be de-energized, and signal S will display a stop sig nal. This has no effect upon the supply of track circuit current to section D-E, but local current of reverse relative polarity is now supplied to this section between impedances 134 and 138 and no local current is su plied to the section between impedanccs .132- and 7 It follows therefore that the tr: entering section D-E at E can pro ceed at speeds below 35 miles per hour as far as impedance 134 where its speed is further reduced to 15 miles per hour.

section C 1) is unoccupied but section BC is occupied, the consequent deenergization of relay reverses the polarity of the current supplied to relay N which thereupon closes its reverse contacts, thus causing lamp 5 of signal S to be energized and the signal to display a caution indication. The local circuits for section DE however are the same as when the track in advan e is unoccupied as described above.

I will now assume that the track to the left of point D is unoccupied, and that a train proceeds from section DE into section CD. Signal S is immediately changed to the stop position by the ole-energization of track relays R and R whose front contacts control the circuit for relay W The entrance of the train into the section doc-snot eifect the track transformers, the track circuit current still being supplied from transformer T Local current of normal relative polarity is also supplied to the rails of the section throughout their length from local transformer N over front contacts of relay N associated with the section 13-6. The train is therefore permitted to pass through section C-D at high speed. If section B-C is occupied, the resulting deenergization of relay Vi closes its back contact and causes the local current between impedauces 134i and 138 in section C-D to be reversed thus imposing an intermediate speed limitation through this portion of track, and causes the local current to be completely removed between the impedances 132 and 134, thus imposing a low speed limitation upon the train through this portion of track.

It should also be pointed out that the entrance of the train into section C--D causes the de-energiaation of the opposing line relay WW. Since relay K is tie-energized, the opening of front contact 17 of relay W deene [Zed relay W. The opening of front contact 168 of relay Vi opens, in turn, the

circuit for relay W which thereupon be comes tie-energized. A train moving from left to right through the section to the left of A cannot now pick up relay G and therefore cannot clear signal S which feature prevents the possibility of a head on collision between points A and D. It is ob vious from the drawing that similar protection is afforded for traflic in the opposite direction, should a train moving from left to right pass point A when the portion of track between points A and D is occupied.

As the train moving from right to left enters section A-B at point B, the two track relays R and R will become de-energized, The closing of back contacts on relay R energizes relay K which in turn picks up relay P The closing of the front contacts of relay P connects primary 8 of transformer T with a source of energy and track circuit current is therefore supplied to the rails of the sections by this transformer. At the same time, the opening of a front conta;;t of track relay R de-enen gizes relay which opens its front contacts and closes its back contacts. A front contact of relay K, which relay is now energized, closes a shunt around impedance 117 normally in series with winding 15 of relay R. Relay Vi is de-energized its circuit having been interrupted by the opening of a front contact of relay R. Consequently, the closing of back contact 71 of relay B does not pick up relay G but relay G is picked up, as are also the simila relays located at the other end of the passing siding F but not shown in the drawing. The operation of these relays is, however, the same as the similar relays at siding and it is therefore apparent that the polarity of the current supplied to relay V will be reversed and the armatures of this relay will swing to the ri 'ht, closing the normal contacts controlled thereby. The circuit for lamp 6 of signal S is now complete and the signal accordingly displays a proceed indication.

It should be borne in mind that the polarity of the current supplied to relay W is controlled by a relay, not shown in the drawing, in the same manner that relay is controlled by relay G It will therefore be clear that when the block to the left of point A is unoccupied, the entrance of the train moving from right to left into section l t- B, by causing the pickup of the G relays at siding F, will cause relay to be energized in the normal direction. If the section immediately to the left of point A is occupied, relay W and also relay G will be (lo-energized, whereas if an opposing train occupies a portion of the block to the left of point A more remote than the first section, that is, the section immediately to the left of A, relay i i/' is energized in the reverse direction. In this latter case signal S is at caution and local current of reverse relative polarity is supplied to the rails of section AB throughout their length from transformer N. A train moving through this section from right to left is therefore held below miles per hour. If relay l/V is energized in the normal direction, lamp 6 of signal S is energized, whereupon this signal displays a proceed indication. Simultaneously, local current of normal relative polarity is supplied to the rails of the section AB throughout their length. If the section to the left of A is occupied however, the consequent de-energization of relays J and G causes lamp 4 of signal S to be energized, thus displaying a stop indication, and causes local current of reverse relative polarity to be supplied to section AB between impedances 13a and 183; but no local current will be supplied to the rails of this section between impedances 132 and 134. A train moving through section AB under these conditions will be allowed to proceed at 35 miles per hour as far as point 134 but will be enabled to proceed past that point only at speeds below 15 miles per hour.

I will now assume that a train moving from left to right enters section AB and stops. As explained above all the opposing line relays ll, 7* and N will be de-energized. If a train moving from right to left enters section C-D at point D it is immedi ately reduced to slow speed because the local circuit for this section is now broken at front contact 170 of auxiliary relay K If this train proceeds, at slow speed, through section CD and enters section B-C, relay K is not energized because the pickup circuit for this relay is broken at front contact 91 of line relay W which is still de-energized. The speed of the train is thus held to 15 miles per hour throughout the portion of track shown in the drawing. A following train is subjected to the same speed restrictions for the same reasons, even though this following train and the first train moving from right to left occupy the same section. 1

If, however, the portion of track shown in the drznving is unoccupied and a train moving from right to left passes into section BC at point C, the de-energization of line relay W and the energization of relay K closes a local circuit for section GD which allows normal operation of a following train, that is, a following train is reduced to 35 miles per hour at point D, and to 15 miles per hour at impedance 134 in section CD.

'l he operation of the apparatus as a train proceeds from left to right through the portion of track shown in the drawing will be readily understood from the foregoing description of the operation of the apparatus when a train moves through the stretch from right to left.

It should be particularly noted that at points B and C the circuits for the auxiliary relays K are such that they will not he picked up unless the opposing line relay W is in the proper position, that is, de-en ergized. This is of importance since it prevents energization of the relays K should the associated line relay stick in its energized position.

Although I have herein shown and described only one form and arrangement of railway traffic controllin 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.

Having thus described my invention, what I claim is:

In combination, a forward and a rear section of railway track, a track relay normally connected with the rails adjacent the one end of said forward section, a stick relay arranged to be energized when said track relay is tie-energized, a track relay for each end of said rear section, a line relay for said forward section controlled in part by the associated track relay and having contacts which constitute a polechanger, a line relay for said rear section, and a circuit for such last mentioned line relay including a source of energy, said pole changer, front contacts on the two track relays for said rear section, and a back contact on said stick relay.

2. Railway traffic controlling apparatus comprising two insulated sections of railway track, a track relay for each section, a line relay for each section controlled in part by the associated track relay, a stick relay for each section, and a circuit for each said stick relay including a back contact on each said track relay and a front contact on one of said line relays and a back contact on the other line relay.

Railway trade controlling apparatus comprising two insulated sections of railway tr ck, a track relay for each section, a line relay for each section controlled in aart by the associated track relay, a stick relay for each section, a circuit for'each said stick relay including a back contact on each said track relay and a front contact on one of said line relays and a back contact on the other line relay, and a second circuit for each said stick relay including a back contact on the associated track relay and a front contact on said stick relay.

#1. Railway controlling apparatus comprising two insulated sections of railway track, a track relay for each section, a line relay for each section controlled in part by the associated track relay, a stick relay for each section, means for energizing each said stick relay only when the line relay of the other section is de-energized, and means including a back contact of the associated track relay for tion as long as is de-ei'iergized.

0. Railway tratic controlling" apparatus maintaining such energizasuch associated track relay compris 'torward and a rear section of ra l ay seen u,

1 said 3 32205;

the rails i salt (3. Railwa t coinprisin a railway track, ward section, a by said track rel rai c source of alter to the rails 15 d res section in parallel.

(. it Llculuc l controlling apparatus comprising ltorward and a rear section of rai way their a track relay for each end or said fOl'lVclC section, a l ne relay controlled in part by said tracl' rela s, a repeater reline relay, means for one 'izing er relay only when aid .no regized; a local trai oriner, and

Li llec u by said repeater relay for onnecting said transformer with rear section in parallel.

in controlling apparatus ii irising a forward and a rear section of track, track re ay for each end of orward section, a line relay controlled in part by said track relays, a repeater relay for 'ne relay, means for energizing said when said line relay is cl: relay for each end or said ticl: relay located at the fora said section arranged to r ener iraed by the or relics of a train into said rear section from said forward sectid an auxiliary relay located at i 1. said rear section, means for the rear or Cl enere"' iu salt auxiliary relay only when '1 y is ener aed, and means conand said auxiliary ibly connecting a source of current with the rails of said ii in pa Ja lcl.

tralhc controlling apparatus torward and a section of -c a track relay for each end a tor-wart section, a line relay con troll d in part by said track relays, a rerelay for said l'rie relay, means for said repe; r relay only when .ec, and means conepeater relay for supplying with local current or one from one end of the section ther or o: the other relative polarity one end to an intermediate point in the 10. Railway traflic controlling apparatus comprising a first, secono and third section of railway track, a track relay for said second section, a line relay, for said second section responsive to reversals of the relati,e polarity of the current supplied thereto, in ans responsive to trallc conditions in said nrst so; 131 for reversibly supplying current to said line relay, a repeater relay arranged to be energized only when said line relay is energized, and means controlled by said line relay and said repeater relay for sugliplying local current to the third section.

11. Railway tra'lfie controlling apparatus coimarising a first, second and third section of railway track, a track relay for said sect a line relay for said second section re spousive to reversals of the relative polarity oi the current supplied thereto, means responsive to trahlc conditions in said first sectic-n for reversing the relative polarity of said current, a repeater relay arranged to be energised only when said line relay is energized, and means controlled by said line relay and said repeater relay for supolying local current of one relative polarity the other to the rails in parallel of said third section.

12. Railway tratlic controlling apparatus comprising a first, second and third section of railway track, a track relay for said second section, a line relay for said second section responsive to reversals or" the relative polarity of the current supplied thereto, means responsive to traliic conditions in said first section for reversing the relative p.0- larity of said current, a repeater relay ar ranged to be energized only when said line relay is energized, and means controlled by said line relay and said repeater relay for supplying said third section with local current of one relative polarity or the other throughout the length of the section.

13. In combination, a forward and a rear section of railway track, a track relay for each section, a line relay for the forward section provided with a controlling circuit which includes a front contact of the track relay for the forward sect-ion, the contacts of said line relay constituting a pole-changer, a line relay for said rear section, a circuit for said latter line relay including said polechanging contacts and a frontcontact of the track relay for said rear section, and train governing means controlled by said latter line relay.

i i. in combination, a forward and rear section of rail vay track, a track relay for each section, a line relay for the torwa section controlled by the track relay for the forward section and having contacts which constitute a pole-changer, a line relay for the rear section having a circuit controlled by the track relay vfor the rear section and by said pole-changing contacts and by an adion,

ditional front contact on said first line relay, a normallyopen stick relay for the forward section, means for closing said stick relayv when a train enters the forward section from the rear section and for keeping it closed at least until such train leaves. the forward section, and a branch for the circuit for said second line relay around said additional front contact of the first line relay and including a front contact of said stick relay.

15. In combination, a forward and a rear section of railway track, a track relay for each section, a line relay for the forward section controlled by the track relay for the forward section and having contacts which constitute a pole-ch nger, a normally open stick relay for the forward section, means for closing said stick relay when a train enters the forward section from the rear section and for keeping it closed at least until such train leaves the forward section, a line relay for the rear section, a circuit for said second line relay including said pole-changing contacts and an additional front contact of said first line relay and a back contact of said stick relay and a front contact of the track relay for the rear section, and a branch forsaid circuit around said additional front contact and said stick relay back contact, said branch including a front contact of said stick relay.

16. In combination, two sections of rail way track, a track relay for each section, a line relay for each section controlled by the track relay for the associated section, a stick relay for one section, and a pick-up circuit for said stick relay controlled by the associated line relay and aback contact of the track relay for the associated section and by a back contact of the line relay for the other section.

17. In combination, a railway track divided into sections, a line relay for each section for governing traflic in one direction along said track, a line relay for each section for governing traffic in the other direction along said track, means for controlling each line relay by the line relay next in advance governing trafiic in the same direction, track relays for the sections for controlling said line relays, a normally open stick relay for each line relay arranged when closed to remove the associated line relay from its control, and a pick-up circuit for each stick relay controlled in part by a back contact of an adjacent line relay governing traffic in the opposite'direction and including a back contact of the track relay for the associated sect-ion.

18. In combination, a forward and a rear section of railway track, a line relay for the forward section responsive to reversals of relative polarity of current, means con: trolled. 1y trai'fic conditions in advance of said to ssctiaafor supplying:

amp? 5 relay with current of one relative polarity or the other, a normally de-energized repeater relay, means controlled by a train in said rear section for energizing said repeater relay provided said line relay is energized in either direction, and means controlledby said repeater relay for supplying to said rear section local train governing current of one relative polarity or the other according as the relay is energized or deenergized. V l

19. In combination, a forward and a rear section of railway track, a line relay for the forward section responsive to reversals of relative polarity of current, means controlled by trar'lic conditions in advance of said forward section for supplying said line relay with current of one relative polarity or the other, a normally de-energized repeate" relay, means controlled by a train in said rear section for energizing said repeater relay provided said line relay is energized in either direction, a signal for said forward section controlled jointly by said line and repeater relays, and means controlled by said repeater relay for supplying to said rear section local train governing current of one relative polarity'or the other according as the relay is energized or deenergized.

20. In combination, a forward and a rear section of railway track, a line'relay for the forward section responsive to reversals of relative polarity of current, means controlled by traflic conditions in advance of said forward section for supplying said line relay with current of one relative polarity or the other, a normally de-energized repeater relay, a normally energized track relay for the rear section, a circuit for said repeater relay including a back contact of said track relay and a contact closed when said line relay is energized in either direction, and means controlled by said repeater relay for supplying to said rearsection local train governing current of one relative polarity or the other according as the relay is energized or ale-energized.

21. In combination, a forward and a rear section of railway track, a line relay for the forward section responsive to reversals of relative polarity of current, means controlled by traffic conditionsin advance of said forward section for supplying said line relay with current of one relative polarity or the other, means for energizing said repeater relay when said line relay is energized in either direction but not when the line relay is de-energized, and means operating when said repeater relay is energized to supply train governing current of normal or reverse relative polarity to said rear section according as said. line relay is energized in one diregtion other, 4

.532; In combinati a terward and a rear section ofrailway' track, a line relay for "the forward section responsive to reversals of relative polarity of current, means controlled by traflic conditions in advance 'of said forward section for supplying; said line re- "is Clo-energized, means operating when said repeater relay is energized to supply train oans-m repeater relay is de-ener -gized.'

governing current 'of normal or reverse relative polarity throughout the length of said rear section according'as said line relay is energize'din one direction or the other, and" means operatingto supply train governing current of reverse relative polarity to a portion only of said rear section When said In testimony whereof I afiiX my signature 1 RONALD A. MOCANN;

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