US1989992A - Signaling system for railroads - Google Patents

Description

Feb. 5, 1935. A. LANGDON' SIGNALING SYSTEM FOR RAILROADS Filed June 25, 1952 2 Sheets-Sheet 1 INVENTOR MM ATTORNEY Feb. 5, 1935. A. LANGDON SIGNALING SYSTEM FOR RAILROADS 2 Sheets-Sheet 2 Filed June 23, 1952 BY J t Flllilllill Patented Feb. 5, 1935 UNI-TED STATES 1,989,992 SIGNALING SYSTEM FOR RAILROADS- Andrew Langdon, Rochester, N. Y., assignor to General Railway N. Y.

Signal Company, Rochester, g}

Application June 23, issaserial No. 618,922

' 11 Claims.

This invention relates to railway signaling, and

more particularly to a check lock circuit for assuring safe interlocking between the signals governing the entrance of trailic at opposite ends of a single track section. 1 I

Sometimes it I happens that two interlocking plants are located only a short distance apart, and that these interlocking plants are connected by several single tracks, each of which normally allows traffic to move in a particular direction, but wherein it may be necessary to reverse the direction of traffic in such section due to congestion, repairs being made on other tracks, or the like. Suitable interlocking means must of course be provided to prevent trafiic being set up in both directions on said single track, check lock or traffic section at one time, and means must be provided for preventing changing the direction of traffic with a train in or approaching the traffic section, unless proper safeguards are introduced.

In accordance with the present invention it is proposed to employ two relays in series, one located at each of the entering ends to such single track section, preferably called lever repeating relays, and to employ a second circuit, preferably called a direction circuit, for checking whether or not these two lever repeating relays are in corresponding positions, and to allow traffic to be set up in one direction when these two lever repeating relays are energized and to be set up in the opposite direction when these two relays are deenergized, the checking circuit being employed to assure against conflicting signal indications being given as might otherwise occur if energy were accidentally applied to an intermediate point of the circuit including the two relays in series, for under this condition one of these relays could be energized and the other remain deenergized. The checking circuit referred to is also employed as a means for selecting between afl'ili- 1 ated signal controlling circuits to enable a re duction' in the line wire requirements between the two ends of the check lock section, this being one of the-primary purposes for controlling non}- automatic' or call onsignals.

Other objects, purposes and characteristic features of the present invention reside in theprovision of suitable time measuring safety means to prevent sudden changes in the direction of traffic being set up, which might endanger a fast moving train approaching either in such section or in an approach section.

Other objects, purposes and characteristic features of the present invention will in part be obvious from the accompanying drawings and will in part be more specifically pointed out hereinafter. i

In describing the invention in detail reference may be had to the accompanying drawings, in which:-

Fig. 1 shows a check'lock circuit embodying the present invention for controlling non-automatic call-on signals; and

Fig. 2 illustrates one manner in which auto matic signals may be sup'erimposed on the system shown in Fig. l to advantage, so that one pair of line wires sufiices to control the home and distant indications of two opposing signals associated with the check lock section.

Structure of Fig. 1

Referring to Fig. 1 of the drawings, the track rails 5 have been shown divided into track sections by insulating joints 6, one section of which constitutes the single track section to which the check lock circuit of the present invention has been shown applied. It is of course understood that suitable switches and crossovers will be em.- ployed beyond the extremities of'the single track section in question, these track switches, crossovers, and the like (not shown), constituting the interlocking plants located at opposite ends of this check lock section. The check 'lock section in question is provided with the usual track circuit including the track relay T and the track battery '7. The normal direction of traffic in thissingle track section is preferably from left to right, or west to east, as indicated by the arrow.

At the east end of the single track section has been shown a non-automatic or call-on signal for controlling the movement .of traffic into said section from that end, asimilar call-on signal being shown at the west end thereof. In the approach section to these signals 10 and 20 have been shown track relays T and T being repeated by approach stick .relays A8 and AS respectively, these approach stick relays having as- Sociated'therewith suitable timing devices such .as thermal relays TR and 'IR v respectively.

At the west end of the single track section has been shown an operators tower OT, in which there is a lever L'for setting up a particular direction of traffic over the single track section. ,This controlling office may be located'at a considerable distancefrom the check lock section, without sacrifice of safety, even though only one line wire and common are employed between the operators tower and the rear end of the check lock section. When this lever L is moved to its abnormal position it energizes a circuit including the lever repeating relays DB andDR connected in series, the relay DB being located near the signal 10 and the relay DB being located near the signal 20. In order to assure that no conflicting signal indications can be given, as for instance might otherwise be true if the line wire 10 were accidentally connected to an unauthorized source, the direction relays 130 and DC have been provided. As is obvious from the drawings one of these relays DC or D0 depending on whether the relays DR and DB are energized or deenergized, is energized through a circuit including the contacts of relays DB and DB assuming corresponding positions. For instance, the relay D0 is shown in its energized condition and is energized through back contacts of the relays DB and DB in series. This en ergizing circuit may be traced as follows: beginning at the terminal of a suitable source of current, front contact 9 of relay DC wire 11, polar contact 12 of this same relay, wire 13, back contact 14 of the relay DB wires 15, 16 and 17, back contact 18 of the relay DB wire 19, winding of the relay D0 wire 20-, back contact 21 of relay DB wires 22, 23 and 24, back contact-25 of the relay DB wire 28, polar contact 27 of the direction check relay D0 wire 28,

neutral contact 29 of the relay D0 and to the other terminal of said source.

The track relay T is also repeated through a track stick relay TS, the pick-up circuit for which may be traced as followsz beginning at the terminal of a suitable battery, front contact 30 of the direction relay D0 wire 31, polar contact 32 of this same relay, wire 33, back contact 34 of the relay DB wires 35 and 36, front contact 37 of the track relay T, wires 38 and 39, through the winding of the relay TS and to the other terminal of said battery.

It will be noted that the relay TS remains up even though the track relay T drops, this through current flowing'in the following stick circuit:-- beginning at the terminal of said battery, front contact 30 of the relay D0 wire 31, polar contact 32 of this same relay, wire 33, back contact '34 of the relay DB wires 35 and 40, heating coil 41 of the relay TR, wire 42, stick contact 43 of the relay TS, wires 44 and 39, winding of the relay TS to the other terminal of said battery. It will be noted that the stick circuit just traced includes the correspondence contacts 32 and 34 of relay D0 and DB respectively.

From this stick circuit it is apparent that if a direction of traflic is changed while the track relay T is deenergized the track repeater stick relay TS will also be deenergized, and that this relay TS may only be picked up after an interval of time if the track relay T remains deenergized, this through the medium of the contact 45 of the thermal relay TR. It may be pointed out here, that the flow of current in the heating coil 41 results inclosure of the contact 45 shunting the contact 37, but that with the relay TS picked up and stuck up the closure of its contact 50 will 'beof no avail until the thermal relay has been fully cooled under "which condition its contact '52 is reclosed. Any other suitable time element device may be employed in lieu of 'a thermal relay if desired, or this protection may, if desired,

be omitted. Also, it will be noted that the callon signal 2C cannot be energized and cleared unless the tl'iermal relay TR is in its normal con- 'dition, thus requiring this relay TR to return to only if the thermal relay TB, is in its normal cooled condition, wire 53, front contact 54 of the relay DC wire 55, polar contact 56 of this same relay, wire 57, signal mechanism of the call-on signal 2C and to the other terminal The direction relay DC is normally energized through the following circuit:- beginning at the terminal of a suitable battery, back contact 50 of the thermal relay TR wire 61, front contact '62 of the approach stick relay AS wire 63, back contact 64 of the relay DB wire 65, winding of the relay DC wire 66, back contact 67 of the relay DR and to the other terminal of said battery. The purpose of the thermal relays TR and TR is the same as that of the thermal relay TR, namely to cause a retarded pick-up of a stick relay, followed by another period of delay necessary to allow cooling of this thermal relay before completion of a second circuit.

Operation of Fig. 1

It will be noted that the call-on signal 20 is in the call-on position whereas the call-on signal 1C is at stop, so that traflic may move in the normal direction as indicated by the arrow. Let us now assume that the operator in the tower OT moves his lever to the reverse position, this in order to set up west-bound trafiic on the single track section. movement of the lever L will energize the direction relays DB and DB thereby breaking the energizing circuits for the relays D0 and D 3 heretofore traced.

Picking up of the relay DB will by its lifting of the contact 34 destroy the condition of correspondence between the contacts 32 and 34 of relays DC and DR so the relay TS will be deenergized, but since the relay D0 is operated to its reverse polarity position, after the period of time required for the signal 20 to assume the stop position to close its contact 8 to complete the pick-up circuit for relay AS the correspondence between the contacts 32 and 34 is reestablished and if the relay T is in its energized condition the relay TS is again picked up without the intervening operation of the thermal relay TR. The relay AS if once up is of course stuck up through its stick contact 88. Also if relay T is down, relay A8 will not be picked up until the thermal relay TR has been energized and closed its front contact.

Picking upof the relay DB will thus result in immediate energization of the direction relay DC with current of reverse polarity through the following circuit;- beg-inning at the terminal back contact 70 of the thermal relay TR wire '71, front contact 72 of the approach relay AS wire 73, front contact 21 of relay Di wire 20, winding of the relay D0 wire 19, front contact 18 of the relay DB and to the other terminal It should be noted that the direction of current flow through the direction relay DC has now been reversed, so that its polar contacts assume the left-hand dotted position, as a result of which the circuit for the call-on signal 20 is broken at the polar contact 56 of the relay D0 in addition to the break previously made at the contact 50 of relay TS.

With the lever repeating relays DR, and DB now both energized and with the direction relay DC assuming its left-hand polar position, the direction relay DC is energized through the following circuit:- beginning at the terminal front contact 50 of the track stick relay TS, wire 51, back contact 52 of the thermal relay TR, wire 53, front contact 54 of the relay D0 wire 55, polar contact 56 of this relay'assuming its lefthand position, wire 75, front contact 76 0f the relay DB wires '77, 16 and '78, front contact 64 of relay DB wire 65, winding of relay DC wire 66, front contact 67 of relay DB wires 68, 23 and 69, front contact 79 of relay DB wire 80, polar contact 81 of relay D0 wire 82, frontcontact 83 of relay DC and to the other terminal It is thus seen that the relays DB and DB must assume corresponding positionsin' order to energize the direction relay at one end ofv the single track section, and furthermore, that the polar direction relay at the other. end of this section must be energized to the proper polar position. Analyzing the various checks from a slightly different angle, it should be noted by referring to Fig. 1, that energization of the relay DR, or DB for any reason, will result in deenergization of the relay D0 this because its energizing circuit includes back contacts of both of the re-- lays DR and DB and that with relay D0 deenergized the call-on signal 2C cannot be set in the call-on position. Furthermore, in order to energize the call-on signal 1C at the other end of the single track section requires its associated relay D0 to assume a polar position, which it can only obtain by current flowing over the line wires 16 and 23, and then only if the relays DB and DB are both energized and the relay DC assumesthe proper polar position, so that there are numerous checks which must be satisfied before the call-on signal 1C can be placed in its proceed position if the system formerly assumed the normal position, and similarly, if the direction of traflic, has once been reversed, numerous checks must be satisfied before normal direction of traiiic can be set up by the other of the signals 1C or 2C.

Structure of Fig. 2

Fig. 2 shows conventionally the same apparatus as shown in Fig. 1 (many parts thereof having been omitted for convenience), but in addition to this apparatus shows how the main semi-automatic signals 1 and 2 associated respectively with the call-on signals 1C and 20 may be controlled. Since the system shown in Fig. 1 affords two polar relays D0 and DC always assuming when energized corresponding polar positions, this feature may be taken advantage of for transmitting favorable indications both caution and clear to the semi-automatic three-position signals 1 or 2, one at a time, in accordance with the direction of travel permitted at that time. In other words, the line wires and 91 may at one time be employed to control the home relay 2H for governing the signal 2, as is normally the case in Fig. 2 of the drawings, but with the polar relays D0 and D0 reversed the same line wires 90 and 91 may be used to control the home relay 11-1 for governing the signal 1.

It will be noted that the polarity of energization of the home-relay 21-1 is reversed by dropping of track relay T through the medium of contacts 86 and 8'7 of track relay T thereby placing the signal 2 in its caution position signifying that the second block in advance is occupied. Also, it should be noted that dropping of the track relay T, through the medium of its contacts 92 and 93, will result in deenergization of the home relay 2H, thereby placing the signal 2 in the stop position manifesting that the block immediately in advance of the signal 2 is occupied. Similarly, if the relays DC and DC assume the left-hand polar position, signifying west-bound traffic, the home relay 11-1 is controlled to a polar position depending upon the position of contacts 94 and 95 of the track relay T but'relay 1H is deenergized if the track relay T is deenergized, this for reasons already explained. .In other words, both of the relays DC and D0 must have their neutral contacts 96, 9'7, 98 and 99 closed, before a home relay 1H or 2H can be energized, and their polar contacts 160, 101, 102 and 103 must assume corresponding positions before either of these home relays IE or 2H can be energized, and these home relays. 1H and 2H are furthermore controlled by the track relay of the block next in advance'and the track relay of the second block in advance of the signal controlled by such home relay.

In the arrange ent shown in Fig. 2 the call-on signals 1C and 2C are controlled in exactly the same way as they are in thearrangement shown in Fig. 1 of the drawings, except that their associated semiautomatic signal 1 or 2 must assume the stop position before such call-on signal can assume its call-on position. This requisite is carried out by the provision of the semaphore contact 57 operated by the signal 2 in the control circuit for the call-on signal 20, a similar contact 59 being included in the circuit for the call-on signal 1C.

It may be pointed out that (see Fig. 1) the approach stick relay AS can only be energized if the non-automatic signal 20 is at stop and if once deenergized cannot be picked up by placing the signal 2C to stop until after a period of delay necessitated by the thermal relay included in its ick-up circuit, but that this delay is cancelled if there is no train in the approach section to the signal 2C due to the shunt aiforded by the front contact 85 of the track relay T What has been said about the relay AS is also true of the relay A8 with respect to its associated apparatus. Referring, however, to Fig. 2 it will be noted that the heating coil of the thermal relay TR includes the semaphore contact 8 of signal 20 and contact 8 of signal 2 in series, so that both of these signals must be at stop to afford a heating circuit for this thermal relay. What has been said about signals 2 and 2C and their associated thermal relay is also true of signals 1 and 1C and their associated relay (not shown in Fig. 2).

It should be noted that the semi-automatic signals 1 and 2 are controlled in the usual way by the home-and- distant relays 1H and 2H respectively, the caution and clear wires being designat- 1 ed cc and cl, respectively. For the signal 2, for instance, the caution wire ca or the clear wire cl is selected by the polar contact 105, and neither of these wires can have current applied thereto unless the neutral contact 106 of relay 21-1 is closed.

Having thus shown a check lock circuit for a particular purpose, this check lock circuit, including numerous checks which must be satisfied before the function which isto be performed can be carried out, and the invention having been shown applied to a particular problem, it is to be understood that the underlying checking features disclosed herein may be applied to other problems encountered in railway signaling, and that modifications and additions may be made to adapt the present invention to the particular problem encountered in practicing the same, all without departing from the spirit or scope of the invention, except as demanded by the scope of the following claims.

What I claim as new is:-

1. In combination, a track section, a signal at each end of said section and governing the entrance of trains into that end of said section, a neutral relay associated with each of said signals,

a manually controlled circuit for at times energizing said relays in series, a signal control relay 'associa d with one of said signals for controlling that s and a circuit, inch; ing front contacts c each of said neutral relays, for-energizing nal control relay, said circuit being governed hy traiiic conditions in approach to said other signal.

2. In combination, a track section, a signal at each end of said section and governing the entrance of trains into that end of said section, a neutral relay associated with each of said signals, a manually controlled circuit for at times energizing said relays in series, a signal control relay associated with one of said signals for controlling that signal, and a circuit for said signal control relay, circuit being governed by said other signal and traffic conditions in approach thereto and including front contacts of said n-eutral'relays.

3. In combination, a track section, a signal at each end of said section and governing the entrance of trains into that end of said section, a neutral relay associated with each of said signals, manually controlled circuit for at times energizing said relays in series, a signal. control relay associated with one of said signals for controllin that signal, a circuit for said signal control relay including front contacts of said neutral relays, and means allowing closure of said circuit following the putting to stop or" said other signal only after said other signal has been put to stop a predetermined time if a train is in approach thereto.

I? o railway nal s the combination with a 5 "le track section, a signal at each end of said section and governing the entrance of trains into that end of said section, a neutral relay associated with each'of a circuit for at times energizing said relays, a second relay associated with each of said signals, and wires extending along sai: section for energizing one or the other or" second relays depending upon whether the contacts of two first mentioned clays are in picked up or retracted positions.

' g 1 system, the combination section, a signal at each'end of said section and governing the entrance of into that end of said section, a neutral e ay associated with each aid signals, a cirfor at times energi, ng relays, a polar relay associated with each of said signals, and cirwi es exten ng along said section for encrone 0: th trier polar relays in acordance with the energized or deenergized conon of said two first mentioned relays. In a i combination with a l c on, a si nal at each end said secti n 9 "ning the entrance of trains into i 11 l l 0;. d section, neutral relay associated with ten of said s a cirrel ys, a second circuit cuit for energ inclu ugh front contacts of said a for clearing one of nials .ine controlled contact for allo lng signals, only at opened for a predetei ltrol oi other of a d second circuit has bee time.

the combination with a'single track a n, a signal at each *end of said section and governing the entrance of trains into that end of said section, a neutral relay associated with each of saidsignals, a'circuit for at times-energizing said-relays, a second circuit including a relay controlled through front contacts of said first mentioned two relays for controlling "one of said'signals, and a third circuit including another relay and controlled "through backcontacts of said first mentioned times "energizing said relays, asecond relay associated with each of said signals, wires extending along said section for energizing one or the other of said second relays 'dependingupon the positicns of the contacts of said two first mentioned relays, a home-and-distant relay for each signal,

and other wires-extending along said section for at times controlling one and at other times controlling the other of said home-and-distant "relays depending upon the positions of the contacts of said two second relays.

9. In a railway signal system, the-combination with a single track section, a signal at each end of said section and ing th entrance of trains into that end of said section, a relay associated with each of said signals, a circuit including said relays in series for at times energizing said relays, and two other circuits including the same line wires at times energized from one end wiih a relay at the other and at times energized from the other end with a relayat said one end dependingupon the condition of energizaticn of said twofirst mentioned relays, for controlling said signals in accordance with the conditions'in said section and in the next section in advance for the particular signal.

10. In a railway signal system, theccrnbination with a single track section, of a signal at each-end of said section for governing the entranceof trains into that end or section, a neutral relay associated with each of said signals, a manually controlled contact, a circuit for energizing said neutral relays in so when said contact is closed, a second relay associated with each of said signals, a second circuit'including one of said second relays and front contacts of saidfirst mentioned two relays for controlling one'of said signals, and a third circuit including the other of said second relays and back contacts of said first mentioned two relays'for controlling the other of said signals.

'11. In combination, a track section, a signal at each end of said section and governing the entrance oftrains into that end of said section, a neutral relay associated with each of said signals, a manually controlled circuit for at times energizing said relays in series, a signal control relay associated with one of said signals for controlling that signal, a circuit for said signal control relay including 'frontcontaots of said neutral re lays, and means allowing closure of said circuit following the putting to stop of said other signal only after said other-signalhas been put to stop a predetermined time if there is a train in said track section.

ANDREW LANGDON

Images