US2133171A - Controlling apparatus for highway crossing signals - Google Patents

Description

Oct. 11, 1938. c. H. LAY 2,133,171

CONTROLLING APPARATUS FOR HIGHWAY CROSSING SIGNALS Original Filed July 2, 1935 2 Sheets-Sheet l INVENTOR I ChaPZaPHLag.

4% a awian HIS ATTORNEY Oct. u, 193%,, c) H. LAY 2,133,171

CONTROLLING APPARATUS FOR HIGHWAY CROSSING SIGNALS Original Filed July 2, 1935 2 Sheets-Sheet 2 ZZZ? 22122 {54 7' A122 t B C X105 2'09 5TH B b @221 Wm 2 E505? 106 Lnm 206L. .1 50 unit 0 01; 525%} QT FL 2a.

film/ HIS ATTORN EY Patented Oct. 11, 1938 CONTROLLING APPARATUS FOR HIGHWAY CROSSING SIGNALS Charles H. Lay, Pittsburgh, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Continuation of abandoned application Serial No. 29,487, July 2, 1935. This application February 8, 1936, Serial No. 62,968

24 Claims. (Cl. 246-130) My invention relates to controlling apparatus for highway crossing signals, and particularly to apparatus controlled by a train approaching the crossing for starting the operation of the crossing signal in accordance with the speed of the train.

This present application is a continuation of my copending application Serial No. 29,487, filed July 2, 1935, now abandoned, for Controlling apparatus for highway crossing signals.

Afeature of my invention is the provision of novel and improved apparatus controlled by a train approaching a highway crossing for registering the speed of the train and then governing the starting of the operation of the highway. crossing signal in accordance with such registered speed.

I will describe three forms of apparatus embodying my invention and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic View of one form of circuits and apparatus embodying my invention. Fig. 2 is a di agrammatic view of a second form of circuits and apparatus which also embody the invention, and Fig. 2a is a fragmental view showing a modified form of the circuits for checking the timing devices of Fig. 2.

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

Referring first to Fig. 1, the reference characters Ia and lb designate the rails of a stretch of railway track over which trafiic normally moves in the direction indicated by the arrow, which rails are divided by insulated joints 2 to form time measuring and signal operating track sections designated IT and 2T, respectively. Each of these sections isprovided with a track circuit including a track battery 3 and with a track relay designated R with a prefix corresponding to its location. The exit end'oi section 2T is intersected by a highway H protected by a signal S of any preferred type. The signal S as here shown conventionally illustrates a combined audible and flashing light highway crossing signal. It will be understood, however, that my invention is not limited to this specific type of signal as any of the standard types may be used. The signal S is normally inactive and is rendered active to give'a warning whenever a train approaches the intersection. The immediate control ofthe signal S is in a mechanism designated FR, which mechanism is eiiective to cause signal S to give a warning in response to current supplied thereto.

The signal control apparatus embodies a chain of counting relays AI-A6 arranged for successive energization during the cyclic operation or interaction of a time element relay TEI and a slow release relay SRI, in cooperation with a controlling relay CR, while a train or'vehicle is occupying the measuring section IT and until it enters the operating section 2T. The time requiredto pick up relays AI and A2 corresponds to that required for a maximum speed train to pass through the measuring section IT, while the additional time requiredto pick up the relays A3A6 of the chain corresponds to the additional timeconsumed by lower speed trains in passing through the measuring section. These latterv relays are employedto correspondingly delay the starting time of the highway signal, as Will subsequently more clearly appear.

The signal control apparatus also includes a second time element relayTEZ and a second slow release relay SR2, which interact While a train occupies the operating section in cooperative relation with the relayv CR to successively effect the release of the energized A relays of the chain. The operation of signal S is started. only when counting relays A3A6 are all in their released position. The particular type of time element relayemployedis immaterial, however, for the purpose of this disclosure it may be assumed that the time element relays TEI and TEZ are of the general type covered by the Lazich and Ash- Worth Patent No. 1,966,965, issued July 17, 1934. In this type of relay, circuit changing contacts are actuated after any desired pre-set period of time and a checking or ofi-normal contact is provided to check that the relay contacts have properly returned to normal when the relay is released. In the present arrangement, a checking relay TEP is normally energized over a circuit including the checking contact I3 of the time element relay TE2 to check the proper return of that relay to its'initial position and to effect operationof the signal S when a train enters the operating section 2T, should the relay TEZ' have failed to return to its normal position following its last operation. 1

v In order to describe the invention in detail, I will first describe the operations which take place when a train moving toward the crossing in the direction indicated by the arrow istraveling at a speed so low. that the counting relays all function to delay the operation of signal S. 1 When a'trainzenters section IT, the track relay ITR releases and completes a circuit for the slow release relay SRI. This circuit-extends from terminal B of a suitable current source, through the back contact 9 of track relay ITR, over conductor 5 and its branch 5a., front contact 4 of relay 2TR, conductor 25, back contact 8 and checking contact H) of time element relay TEI, winding of relay SRl, and to terminal C of the same current source. Relay SRI now picks up and completes a circuit for the time element relay TEL This circuit extends from terminal B at the back contact I65 of counting relay A6, over conductor 69, front contact 38 of relay SRl, winding of relay TEI, and to terminal C. The relay SRI also completes a stick circuit for itself at its front contact 31 which circuit excludes the checking contact IU of relay TEI.

The time element relay TE| upon becoming energized immediately opens its checking contact 0. After the expiration of a predetermined time interval, the back contact 8 opens the stick circuit for relay SRI. After a slight delay, relay SRI releases and at its front contact 38 reopens the operating circuit of relay TEL When relay TEI releases, it recloses the circuit of relay SRL It will be apparent therefore that the above cyclicoperation or interaction of relays SRI and TEI will repeat itself and will continue until the train enters section 2T, releasing relay 2TR and opening front contact 4 which interrupts the circuit of relay SRI, or alternately, until the circuit of relay TEI is interrupted by the opening of back contact [65 of relay 'AB, as will be. made clear hereinafter.

The first time that relay TE| picks up at the expiration of its time interval as described above,

- it completes a circuit for the counting relay AI.

This circuit extends from terminal B of the current sourceover back contact 9 of relay ITR, conductors 5 and 5a, front contact 4 of relay 2TR, conductor 25, through the front contact 8 of relay TEI, the pick-up conductor PU over which all A relays are picked up, back contact |6 of relay CR, pick-up. conductor PUl over which all of the odd numbered A relays are picked up, back contact 23 of relay A21, winding of counting relay Al, and to terminal C.

When relay A'l picks up, its front contacts l2, l3, and I4. close and thereby prepare pick-up circuits for relays A2, CR, and TE2, respectively. Also, front contact I! closes a stick circuit. for relay A| itself. This latter circuit extends from terminal B of the current source now connected with conductor 5 by back contact 9 of relay ITR thence over branch wires 51) and 50, back contact l'la of relay CR, release control conductor RC|- over which .all odd numbered A relaysv are. re-

leased, back contacts, 62a, 5|, 42a, 3|, and 22a of relays A6, A5, A4, A3, and A2, respectively, its own front contact winding of relay AI, and to terminal C.

A slight interval of time after relay TEI picks up, relay SR releases, and at this time merely interrupts the circuit of relay TEL Whenrelay TEI releases the first time, itmerely recloses. the pick-up circuit for relay SR1.

When relay SRI; picks. up. the. second time, however, it completes a pick-up. circuit for relay CR, due to the pick up of relay Al in themeantime. This circuit extends. from. terminal Bzoyer back contact Ia of relay TEI, through front contact 40 of" relay SRI, conductors l9: and I911; back contacts 64, 54, 4'4, 3'4, and 2.4: of counting relays A6, A5, A4, A3, and A2, respectively, the front contact |3 of relay Al, conductor 28;.winding of relay CR, and to terminal. C'.

. The relay CR now picks upand at its front contact l8 connects the pick-up conductor PU with the pick-up conductor PU2 over which all even numbered A relays are picked up. The relay CR also at its front contact H closes an auxiliary stick circuit for relay A| including the release control conductor RC, the back contact H of relay TE2 and branches 51, 5d, and 5b of conductor 5. At the same time, relay CR opens the initial stick circuit of relay A| at the back contact Ha.

When relay TEI picks up the second time, front contact 8 completes the pick-up circuit for counting relay A2. This circuit extends over front contact 8, pick-up conductor PU, front contact l6 of relay CR, conductor PU2, front contact |2 of relay Al, back contact 33 of relay A3, winding of relay A2 and to terminal 0. The relay TE| also closes at its front contact a stick circuit for relay CR and at its back contact 1a opens the pick-up circuit of relay CR. The stick circuit of relay CR extends from contact of relay TEI, over conductors 28a, 29, and 20b, through back contact T6 of relay SR2, conductors 28a and 28, contact [5 and winding of relay CR, and to terminal C.

When relay A2 picks up, it transfers the stick circuit of relay Al from its back contact 22a to its front contact 22; at front contact 23 prepares the pick-up. circuit of relay A3; and at back contact 24 opens a second point in the above-traced pick-up circuit of relay CR. Relay A2 also completes a stick circuit for itself at front contact 2| which circuit extends over contactors 5, 5b, and 50, front contact l8 of relay CR, conductor RC2, back contacts 6|, 52a, 4|, and 32a. of relays A6, A5, A4, and A3, respectively, front contact 2| of relay A2, winding of relay A2, and to terminal C.

When relay SRI releases, the second time, its back contact 39 connects terminal B to the conductor 20, to maintain relay CR energized independently of the front contact of relay TEI. When relay TEI releases the second time, it merely recloses the previously traced pick-up circuit of relay SRI.

When relay SRI picks up the third time, its back contact 39 opens the stick circuit of relay CR. The relay CR now releases. and at its back contact |6 reconnects the pick-up conductor PU to pick up conductor PUI which is included in the pick-up circuits of the odd numbered A relays. The. relay CR also transfers the stick circuit of relay A2 from the path including; its front contact |8 to the path including. its back contact |8a and the branch conductor RC.

When relay TEI picks up the third time, its front contact 8 completes the prepared pick-up circuit for relay A3. This circuit is the samev as that traced for relay Al up to conductor PUI thence over front contact. 23 of relay A2, back contact 43 of relay A4, winding of relay A3, and to. terminal C.

When relay A3 picks. up, it transfers the stick circuit of relay A2 from the back contact 32a to the front contact 32; at front contact 33 prepares the pick-up circuit of relay A4; andat front contact 34 prepares a new pick-up circuit for relay CR, which circuit excludes front contact l3 and. back contact 24.- of relays Al and A2, respectively. The relay A3 at its back contact 35, also opens a pointv in the. main. circuit of mechanism FRwhich is employed to render signal S. active. This circuit extends from. a terminal B, through back contacts 65, 55, 45, and 35 of relays A6, A5, A4, and A3, respectively, cone.

ductors so and 50a, back contact as of may 2TR,

now open, and through mechanism FR to a ter--' minal C. RelayA3 on closing its front contact 3| completes its stick circuit which extends over conductors 5, 5b, and 50, back contact Ila of relay CR, conductor RCI, back contacts 62a, 5|, and 42a of relays A6, A5, and A4, respectively, front contact 31 and winding of relay A3, and to terminal C.

When relay SR! releases the third time, it performs no particular function other than to open the circuit for relay TE]. When relay TEI releases for the third time its back contact 1a again prepares the pick-up circuit for relay CR. The release of relay TE I closes the circuit forrelay SRI, and when relay SRI picks up the fourth time, its front contact 40 completes the prepared pick-up circuit for relay CR.

Relay CR now picks up the second time and its front contact Hi again prepares the pick-up circuit of the even numbered counting relays. Relay CR also transfers the stick circuit of relay A3 from its back contact Ila and branch conductor 50 to its front contact H and the release control conductor RC and branch 5) of conductor 5, in the same manner that the stick circuit of relay Al was transferred when relay CR picked up for the first time.

The subsequent cyclic operation of relays TEI, SR!, and CR, which results in the sequential energization of counting relays A4, A5, and A6 will be clear from the drawings and from the foregoing description so that a detailed description of the repeated relay operations involved in such energization of the counting relays is believed to be unnecessary. It will be sufficient to state that when the counting relays have completed a full cycle of operation, relays Al to A6 all be energized, relays TE! and CR will both be deenergized, and relay SRI will be energized.

The foregoing operations are those which take place when a train or vehicle enters the measuring section lT provided the train remains in such section for a sufficiently long period of time, that is, provided it is a slow speed train. No further operations take place thereafter until the train enters the operating section 2T.

When the train enters section 2T, the track relay ZTR releases and at its front contact 4 opens the circuit of relay SRI. The relay SRI accordingly releases, but its release accomplishes no immediate result. When relay ZTR releases, its back contact Bl connects terminal B to branch 5e of the conductor 5 so that conductor 5 and all its branches will continue to be connected to terminal B of the current source even after the train clears section IT and relay ITR again picks up. The relay 2TR at its back contact 66 completes an auxiliary circuit for the mechanism FR of signal S which extends from the B terminal connected through the contacts 15 and of relays SR2 and TEP to the conductors 5110, 59b, and 500.. At its back contact 68, relay 2TR completes acircuit for the slow release relay SR2, which circuit extends from terminal B over back contact 68, back contact 12 of time element relay TE2, front contact 19 of relay TEP, winding of relay SR2, and to terminal C.

When relay SR2 picks up, it opens back contact '15 to open one of the auxiliary circuits through mechanism FR of signal S; at front contact l4 completesa stick circuit around the front contact 19 of relay TEP; and at front contact .18

closes the operating circuit of the time element relay TE2. This latter circuit extends from terminal B. through front Contact l4 of relay Al,

conductor 21, front. contact 18 of relay SR2, winding of relay TE2, and to terminal C. The relay SR2 also, at back contact 16, opens a point in the stick circuit of relay CR, but without effect even should that relay be energized at the time,

for the reason that front contact ll will under such circumstances close a pick-up circuit for relay vCR as will subsequently be explained. Should the'relay SR2 for any reason fail to pick up, the circuit completed at its back contact 15 will become effective to actuate signal S without further delay.

When the time element relay TE2 becomes energized, it first opens the circuit of relay TEP at checking contact 13 and then some time lateractuates its other contacts. The relay TEP im mediately releases, opening the pick-up circuit of relay SR2 at its front contact 19 and at its front contact 80 opens the other of the auxiliary circuits traced through the mechanism FR of signal S, to prevent operation of the signal at this time. Should the relay TE2 for any reason fail to pick up, the relay TEP will not be released and the circuit traced through its front contact 80 and mechanism FR will become effective to actuate the signal S without further delay. When relay TE2 fully picks up, its back contact '52 opens the stick circuit of relay SR2.

When relay SR2 releases, its front contact 18 opens the circuit of relay TE2. The relay TE2 then releases and recloses. its checking and back contacts 13 and 12. The relay TEP now picks up and at its front contact 19 again completes the pick-up circuit of relay SR2. 'It will be evident from the foregoing that relays SR2, TE2, and

TEP interact as long as the operating section 2T the last picked up A relay of the chain. In the present instance, the stick circuit of relay A6 is interrupted.

When relay A6 releases, it transfers the, stick circuit of relay A5 from the path including its front contact 62 to the path including itsback contact 62a; and its back contact 64 prepares a pick-up circuit for relay CR; and at its back contact 65 recloses a point in the first circuit traced through mechanism FR of signal S.

A slight interval after relayTE2 picks up, relay SR2 releases, but at this time is merely effective to interrupt the circuit of relay TE2.

When relay TE2 releases the first time, its back contact 18 closes a point in a pick-up circuit for relay CR, and its back contact ll again closes a point in a circuit including release control conductor RC, which comprises'a part of a common release control circuit for all of the relays Al A6.

Whenrelay SR2 picks up the second time, it completes the prepared pick-up circuit of relay CR. This circuit extends from a terminal B through back contact 10 of relay TE2, front contact ll of relay SR2, conductor l9a, back contact .64 of relay A6, front contact 54 of relay A5, over conductors 26b, .26a,-and 26, winding of relay CR, andto terminal C.

The relay CR now picks up and transfers the stick circuit of relay A5 from the path including itsback contact Ila and branch 50 of conductor 5 to the path including its front contact ii, the release control conductor RC and the back contact ii of relay TE2.

When relay .TE2 picks up the second time, its front contact 59 closes a stick circuit for relay CR including the conductors 23c, 20 and the back contact 39 of relay SRI, so that the opening of the pick-up circuit of relay CR at back contact HI is without effect. The relay TE2 at its back contact H now opens the stick circuit of relay A5.

When relay A5 releases, it transfers the stick circuit of relay A4 from the path including its front contact 52 back to the path including its back contact 52a, release control conductor RC2, front contact E8 of relay CR and branch 50 of conductor 5. Relay A5 at its front contact 54 opens a point in the last employed pick-up circuit of relay CR and at the back contact 5 1 closes a point in an alternative pick-up circuit for relay CR. The relay A5 also, at back contact 55, recloses another point in the first traced circuit including mechanism FR of signal S.

A slight interval after relay TE2 picks up, relay SR2 releases for the second time, and at its back contact 76 closes a multiple branch of the stick circuit for relay CR which is independent of front contact 69 of relay TE2. When relay TE2 releases the second time, its back contact ll again closes a point in the release control circuit of the relays Al-A6. When relay SR2 picks up the third time, its back contact 16 opens the stick circuit of relay CR.

The relay CR now releases and transfers the stick circuit of relay A4 from the path including its front contact l8 and branch 50 of conductor 5, to the path including its back contact 18a, release control conductor RC, and the back contact l i of relay TE2.

When relay TE2 picks up the third time, its back contact li opens the stick circuit of relay A4, which in releasing, transfers the stick circuit of relay A3 from the path including its front contact 42 back to the path including its back contact 42a; at its back contact 44 closes a point in one of the pick-up circuits for relay CR; and at back contact 45 recloses another point in the main circuit including mechanism FR of signal S.

A slight interval of time after relay TE2 picks up, relay SR2 releases for the third time, but at this time the latter relay merely interrupts the circuit for relay TE 2. When relay TE2 releases for the third time, its back contact 10 again closes a point in the pick-up circuit of relay CR, while its back contact H again closes a point in the common release control circuit for relays Al-Afi. When relay SR2 picks up the fourth time, its front contact TI completes the pick-up circuit for relay CR which was prepared by the closure of back contacts 44 and 1B of relays A4 and TE2, respectively.

The relay CR now picks up and transfers the stick circuit of relay A3 from the path including its back contact Fla and branch of conductor 5, to the path including its front contact I1, the release control conductor RC, and the back contact ll of relay TE2.

When relay TE2 picks up the fourth time, its front contact 69 again closes the stick circuit for relay CR to prevent this relay from being released by the opening of its pick-up circuit at back contact l0. Relay TEZ also opens the stick circuit for relay A3 at its back contact H so that when relay A3 releases, its contacts 3l35 perform functions similar to those performed by the contacts 5 lof relay A5 on its release. The back contact 35of relay A3, it will be observed, was the last open point in the main circuit including the mechanism FR of signal S. The operation of signal S will accordingly begin as soon as contact 35 closes and this operation will continue until relay 2TR picks up following the exit of the train from section 2T.

During the next two cycles of interaction of relays SR2 and TE2, the relays CR, A2, and Al are released in a manner which will be apparent in the light of the foregoing description.

When relay Al releases, its front contact l4 disconnects terminal B from the circuit of relay TE2, thus preventing the latter relay from again picking up. With relay TE2 in its released position, the checking relay TEP remains picked up, thereby checking that the relay TE2 has fully released. With relay TE2 released, relay SR2 again picks up and remains picked up until its circuit is interrupted by the picking up of the track relay 2TR.

When relay 2TB. picks up, it opens at its back contact 66 a common point in the main and auxiliary circuits of the signal control mechanism FR, thereby stopping operation of signal S. Relay ZTR also opens the pick-up and stick circuits of relay SR2 at back contact 58 so that relay SR2 will release, thus again placing the circuits in their normal condition.

If a vehicle or train traveling at or near its maximum speed, assumed as being 90 miles per hour, for example, enters section IT, it will pass on into section 2T before the relay A3 has been picked up whereby the main control circuit through mechanism FR of signal S will be closed at back contact 66 of relay 2TR as soon as the train enters section 2T and will remain closed until the train clears this section. The length of section 2T obviously determines the time of operation of the signal S for maximum speed trains, and this length will ordinarily be such as to allow the signal S to be operated for a 20 second period.

If a train approaching the crossing is traveling at a speed slightly below maximum, '75 miles per hour, for example, relays A|-A3 Will have been picked up prior to the entry of the train into section 2T. Under these circumstances, the main circuit through mechanism FR of signal S will be open at the back contact 35 of relay A3 when the train enters section 2T. The commencement of operation of the signal will therefore be delayed until relays SR2, TE2, and CR have completed the cycle of operations necessary to effect the release of relay A3.

More specifically, when the train enters section 2T, relay SR2 picks up and at its front contact l1 completes one of the pick-up circuits of relay CR. The relay CR now picks up and transfers the stick circuit of relay A3 from the path including its back contact Ila and branch 50 of conductor 5 to the path including its front contact H, the release control conductor RC and the back contact H of relay TF2.

When relay TE2 picks up, its back contact II opens the stick circuit of relay'A3, which accordingly releases and closes the main circuit through mechanism FR of signal S to start operation of the signal substantially 20 seconds before the train reaches the crossing.

If a train approaching the highway is traveling at a speed of 60 miles per hour, for example,

relays AI-A4 will have been picked up prior to the entry of the train into section 2T. Under these circumstances, the main circuit of mechanism FR of signal S will be open at back contacts and of relays A3 and A4 when the train. enters section 2T. The commencement of operation of signal S will therefore be delayed until relays SR2, TEZ, and CR have completed the cycles of operation necessary to effect the release of both relays A4 and A3.

In this instance, when relay SR2 picks up, it does not close a pick-up circuit for relay CR, such circuit being open at back contact 44 of relay A4. When relay TE2 picks up, its back contact II opens the stick circuit of relay A4, which relay releases, and at its back contact 45 closes one point in the main circuit of mechanism'FR, and prepares a pick-up circuit for relay CR at its back contact 44. Relays SR2 and TE2 now release, in sequence.

The cycle of operations which follows is the same as previously described and need not be repeated, it being understood that the operation of signal S will start, as before, when relay A3 releases.

If the train approaching the highway is traveling at a speed of 45 miles per hour, for example, the relays AIA5 will have been picked up prior to the entry of the train into section 2T. Under 1 these circumstances the main circuit of mechanism FR will be open at contacts 35, 45, and "of relays A4, A5, and A6, respectively, and the commencement of operation of signal S will accordingly be delayed until relays SR2, TEZ, and CR have completed the cycles of operation necessary to effect the release of relays A3-A5.

In the foregoing description, it will be observed that the pick-up and stick circuits of relay SRI include the back contact 9 of relay ITR, and that the circuit of the last operated counting relay in all instances also includes this back contact. Therefore, if a train enters the measuring section IT and then backs out of. the section, relay SRI and the operated counting relays will all release and will be ready for operation when a train again enters the measuring section.

Referring now to Fig. 2, rails Ia and lb comprise a single track stretch over which trafiic may approach the highway H from either direction. The track sections A2T and AIT, respectively, correspond to sections 2T and IT of Fig. 1 and these sections are equipped with like track circuits including track relays A2TR and AITR, respectively.

In this form of my invention, I employ separate timing devices THI, TH2, and TH3 of the thermal type to successively pick up the signal control relays RI, R2, and R3, while a train approaching the highway occupies one or the other measuring section IT or AIT, respectively. Separate thermal timing devices ITH, 2TH, and 3TH are used for successively releasing the signal control relays after a train approaching the highway has entered the operating section 2T or A2T. A relay CH is used for checking the integrity of the timing devices ITH, 2TH, and 3TH. The selective control of the signal S by the previously mentioned timing devices and relays is obtained by means of an interlocking relay HR, the two windings WI and W2 of which are controlled by trams to the left and right of the highway, respectively, as described hereinbelow.

When a train approaching the highway from the left enters section IT, the track relay ITR releases and at its front contact interrupts a,

normally closed circuit including the frontcontact 4 of relay 2TR, and the winding -WI of relay HR. When relay HR releases, its back contact 8I closes a circuit through the winding of thermal timing device THI to initiate the operations required to determine in accordance with section, when operation of signal S will be started. This circuit extends from terminal B through back contact 8|, front contact 66 of relay 2TR, conductors 85a and 85, back contact IOI of relay RI, winding of timing device THI, and to terminal C. The timing device THI is adjusted to close its contactQI only if the train entering the measuring section consumes more than a minimum predeterminedtime interval in such section prior to its'entry into the adjacent op-' erating section. Therefore, if the train is moving at the maximum speed, it will enter section 2T before contact 9| has had time to close;

Under such circumstances, when the train enters section 2T and track relay 2TR releases, the circuit through the winding of THI is interrupted at the front contact 66 of relay ZTR, thereby preventing the closure of contact 9|. At the same time, the relay 2TR at its back contact 6'! completes the main operatingcircuit through mechanism FR of signal S. This circuit extends from terminal B, through back contact 30 4 of relay R3, conductor 208, the-back contact 204 of relay R2, conductor I08, the back contact I04 of relay RI, conductors 50 and 50a; the back contact 82 of relay HR, back contact 61 of relay 2TR, and through the mechanism FR, to

terminal C. From the foregoing, it will be apparent that when a maximum speed train approaches the highway, thesignal S will start operating when the operating section is entered and will continue to operate until the train clears such operating section. I

I will now assume that thetrain advances through section IT at a somewhat lower speed, so that contact SI of the timing device THI has had time to close before the train entered section 2T. 7

When contact 9| closes, relay RI picks up and at its back contact IOI opens the circuitthrough the winding of the timing device THI. The front contact IOI substitutes a circuit including the back contact 20I of relay R2 and'the winding of timing device TH2, for the winding of THI, so that the closing movement of contact 92 of the timing device TH2 is immediately started. The relay RI, at its front contact I02, prepares a se-, ries circuitincluding the winding of the timing device ITH and-relay CH; at its back contact I04 opens a point in the operating circuit through mechanism FR; and at its front contact I03 closes astick circuit for itself through the normally closed contact I05 of timing device ITH.

If the speed of the train is only slightly below the maximum, the train as it enters section 2T will releaserelay 2TR and consequentlyinterrupt the operating circuit of timing device TH2 before this device has had time to close its contact 92. When this occurs, theback contact'fifi of relay 2TR will complete the eviously prepared circuit including the windings of relay CH and of timing device ITH. This circuit extends frorn terminal B, through the back contact 8| of relay HR, back contact 66 of relay ZTR, conductors 86 and 86a, the winding f relay conductor 850, front point of contact I02 of relay RI, and the winding of the tim deVlce 3TH, to terminal 0. If this circuit is intact, the

' the speed of the train through the measuring checking relay CH immediately picks up and opens its back contact to remove connection of terminal B from conductor 50b, thereby preventing the mechanism FR of the signal S from actuating the signal on closure of the back contact 61. of relay 2TR at such time as the formerly traced main circuit through mechanism FR is open. After the expiration of a time interval determined with respect to the time required for the train to come within 20 seconds running time of the crossing, contact I05 of the timing device ITH opens the stick circuit of relay RI, releasing this relay and at its back contact I04 completing the circuit through mechanism FR of signal S, to start operation of the signal.

It will be apparent that if the speed of the train through section IT is materially less than last assumed, the circuit through the winding of the timing device THZ will remain closed for a suflicient time period to effect the closure of contact 92. In such a case, relay R2 will pick up and at its contacts 20I--204 will perform circuit changes similar to those brought about by the closure of contacts IOI--I04 of relay RI. A slow train entering section 2T, by causing the release of relay 2TR, prevents the timing device TH3 from closing its contact 93, and closes the series circuit through the windings of relay CH and timing device ITH. The relay CH immediately picks up, thus preventing operation of the signal, as before. When the contact I05 of the timing device ITH opens, relay RI releases but although its back contact I04 closes, the signal control circuit is inoperative because this circuit is still open at back contact 204 of relay R2. With relay R2 pickedup, when relay RI releases, its back contact I02 connects the winding of timing device 2TH to conductor 860 by way of the front contact 202 of relay R2. When contact 205 of the timing device 2TH opens, relay R2 releases and at its back contact 204 completes the circuit through mechanism FR to start operation of the signal S. The added delay in operation of the signal introduced by the timing device 2TH is such as to allow the lower speed train to approach within approximately 20 seconds running time of the crossing before operation of the signal is started.

In case a still lower speed train enters section IT, the winding of the timing device TH3 will be included in circuit with conductor over the obvious path including the front contacts IN and 20I of relays RI and R2, and the back contact 30I of relay R3, a sufficient period to close front contact 93 of timing device TH3. After the expiration of a period of time suflicient to close contact 93, relay R3 will pickup. When relay R3 picks up, its back contact 304 opens a further point in the main operating circuit of mechanism FR; its front contact 302 prepares a circuit for the winding of the associated timing device 3TH; and its front contact 303 completes a stick circuit for the relay itself. a

When the train finally enters section 2T, operations fully described hereinbefore take place preparatory to closing of the main circuit through mechanism FR. When the back contact 204 of relay R2 closes, operation of the signal will not take place immediately because of the open back contact 304 of relay R3. After the added delay introduced by the operation of the timing device 3TH in opening contact 305 and effecting the release of relay R3, back contact 304 closes and completes the circuit through mechanism .FRJ to start the operation of signal S at least 20 seconds before the train can reach the intersection.

When the train clears section IT, the relay ITR v will again pick up. When the train enters section A2T, relay A2TR will release and at its front contact corresponding to contact 4 of relay 2TR, will open the circuit for winding W2 of relay HR. Owing to the mechanical interlocking incorporated in relay HR, the contacts associated with winding W2 cannot now close and therefore the release of relay A2TR, when released by a train moving to the right, can exercise no control over the signal control apparatus.

When the train clears section 2T, relay 2'IR again picks up; its backcontact 61 opens the circuit of signal mechanism FR to stop operation of the signal; and front contact 4 recloses the circuit including winding WI of relay HR which. relay accordingly closes its contacts BI and 82. When the train finally clears section AIT, the circuit through winding W2 of relay HR is again completed and this relay is now in condition to fully release the proper contacts, depending upon the direction from which the train is approaching the intersection.

The signal control apparatus functions in the same manner whether a train approaches the intersection from one or the other direction and it will therefore be unnecessary to describe the operations which occur when a train approaches the intersection from the right.

As previously brought out, relay CH functions to check the integrity of the operating circuits of the timing devices ITH, 2TH, and 3TH. If one of these devices should fail to respond, due to an open circuit, for example, relay CH will not pick up so that operation of the signal S will be started without further delay.

In Fig. 2a, I have shown sufiicient of the apparatus of Fig. 2 to illustrate an alternative way in which the failure of operation of signal S due to failure of a timing device may be guarded against. Inthis form of the invention, the relay CH is omitted and conductor 86a terminates in contact I02 of relay RI and therefore forms a part of the energizing circuits of the timing devices ITH, 2TH, and 3TH, exactly as in Fig. 2.

These timing devices as employed in Fig. 2a each' have an additional normally closed contact, designated I06, 206, and 303, respectively, each of which is adjusted to open an instant after its associated winding becomes energized. The branch conductor 50b, which in Fig. 2 receives current through the back contact of relay CH to complete an auxiliary circuit for mechanism FR receives current over a series path including contact I06, conductor I08, contact 206, conductor 208 and contact 306 to likewise operate the signal S independently of the main operating circuit whenever a train enters an operating section and any one of the timing devices ITH, 2TH, or 3TH fails to operate. This condition always exists when a maximum speed train enters one of the operating sections 2T or A2T. In the case of a lower speed train, however, relay RI will have been picked up before such train entered an oper ating section, and if the timing device ITH should fail to respond, its contact I05 will fail to interrupt the auxiliary operating path and the signal S will accordingly'start operating immediately.

In caseboth relays RI and R2 have been picked up and timing device ITH has functioned properly by opening its contact I06 to prevent actuation of the signal immediately when the train entered the operating section, then if the timing device 2TH fails to respond following the'release of relay RI, an auxiliary path for operating the signal S will be provided which path includes conductor a, back contact I04 of relay RI, conductor H38, and'the remaining portions of this series path.

It will be apparent that if after relay R3 has been picked up and timing devices ITH and 2TH have functioned properly following the entry of the train into an operating section, then if the device 3TH fails to respond the auxiliary operating path for signal S including conductor H18, back contact 204 of relay R2, conductor 2%, and contact 306 of device 3TH will not be interrupted and operation of the signal S will therefore be started at once.

If single direction control of the signal S is all that is required, the relay HR may be omitted and a track relay contact arrangement similar to that shown in Fig. 1 employed. On the other hand, the form of the invention illustrated in Fig. 1 may also be employed to control the signal S by trains approaching the intersection from either direction. In such a case, an HR, relay and a track relay contact arrangement similar to that shown in Fig. 2will be required.

Although I have herein shown and described only three forms of 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. 7

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track including a measuring section and an operating section each equipped with a track circuit including a normally energized track relay, said operating section having a highway intersecting the exit end thereof, a warning device at the intersection operative to warn traffic on the highway of the approach oftrains; a chain of relays for registering, bythe number of them which become operated, the time consumed by a train after its entry into the measuring section prior to its entry into the operating section of the stretch, means under control of the track relay of the measuring section when a train enters it for initiating the successive operation of the relays of said chain, means controlled by the track relay of the operating section when the train enters it for preventing any non-operated relays of the chain from being thereafter operated, a second timing device placed under control of the track relay of the operating section when the train enters it to successively eifect the release of the operated relays of the chain, and an operating circuit for said warning device including back contacts of relays of said chain and of the track relay of said operating section.

2. In combination, a stretch of railway track intersected by a highway, a normally inactive highway signal control circuit, a first contact included in said circuit, train controlled means for actuating said contact to render said circuit active when a train approaching the intersection reaches a predetermined location in such stretch, time measuring means including a chain of relays arranged for consecutive operation, train controlled means for starting the operation of said said'highway signal control circuit from becoming active when saidfirst contact is actuated, and means controlled by a train reaching said predetermined location prior tothe time said other contacts become eflective for rendering said other contacts ineffective thereafter.

3. In combination, two successive sections of railway track, a highway intersecting said track adjacent the exit end of the second section, a highway signal, a track circuit for eachsection including a track relay, a chain of relays, means controlled by the track relay of the first section for initiating the sequential operation of the relays of said chain, means controlled by the-track relay of the second section for stopping the operation initiated by thetrack relay of the first section' and for starting the sequential release of the operated relays of the chain, means also controlled by the track relay of the second section for starting the operation of said signal, and means for delaying the operation of said signal for a time period determined by the number of relays of the chain which have been operated and the time required to effect their release.

4. In combination, a stretch of railway track intersected by a highway, a highway signal located at the intersection, means for setting said signal into operation as a train approaching the highway from either direction reaches a point a fixed distance from the intersection, a group of relays, timing means set into operation by the entry of a train into the stretch from either direction and arranged to successively energize relays of said group until the train reaches said fixed distance from the highway, other timing means arrangedwhen operating to successively effect the release of the energized relays of said group, means for disabling said first mentioned timing means and starting the operation of'said other timing meanswhen the fixed distance from ,1

the highway is reached by the train, and means controlled jointly by the energized relays of said group and by said other timing means to delay the starting of the operation of said signal until the energized relays of said group'have all been approaching said intersection for successively picking up one or more of said relays according as the speed of the train is at its maximum or at some lower value, means controlled by the approaching train for effecting the sequential release of the operated relay or relays of said chain, and means for initiating the operation of said signal when the relays of said chain have all been released.

6. In combination, a stretch of railway track intersected by a highway, a highway signal lo-' cated at the intersection, means for setting said signal'into operation when a train reaches a fixed point in said stretch, a group of relays, timing means set into operation by the entry of a train into the stretch and arranged tosuccessively energize relays of said group until the train reaches said fixed point, other timing means arranged when operating to successively release the energized" relays of said group, means for disabling said first-mentioned timing means and for starting the operation of said other timing means when the fixed point is reached, and means con-' trolled jointly by the energized relays of said group and by said other timing means to delay the starting of the operation of said signal for a time depending on the number of relays of said group which were picked up and then released.

7. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a chain of stick relays, timing means responsive to the entry of a train into a first portion of the stretch, means including said time measuring means for picking up a variable number of the relays of said chain in accordance with the time consumed by a train while occupying said first portion of the stretch prior to its entry into a second portion of the stretch, other timing means for effecting the successive release of the operated stick relays of said chain, means for stopping the operation of said first mentioned timing means and ,for starting the operation of said other timing means when the train enters said second portion of the stretch, and means for setting said signal into operation when certain of the picked up relays of said chain have been released.

8. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, control means for starting the operation of said signal when a train reaches a fixed point in said stretch, a chain of relays, certain relays of said chain acting when energized to prevent said signal from being operated by said control means, a first time measuring device responsive to the entry of a train into the stretch for successively energizing the relays of said chain, a second time measuring device for successively effecting the release of the energized relays of said chain, and means operated by said control means for stopping the operation of said first time measuring device and starting the operation of said second time measuring device.

9. In combination, a stretch of railway track divided into two track relay equipped sections one of which is intersected by a highway, a highway crossing signal located at the intersection, a stick relay, a timing device for picking up said stick relay and set into operation by the track relay of the section which is first entered by a train approaching the highway, a second timing device having normally closed contacts, a stick circuit for maintaining said stick relay energized including said normally closed contacts of the second timing device, a circuit for said signal including back contacts of said stick relay and of the track relay associated with the section intersected by the highway, and an operating circuit for said second timing device also including a back contact of the track relay associated with the section intersected by the highway.

10. In combination, a stretch of railway track divided into two track relay equipped sections one of which is intersected by a highway, a highway crossing signal located at the intersection, a stick relay, a timing device for picking up said a stick relay and set into operation by the track said signal including back contacts of said stick relay and of the track relay of the section intersected by the highway, and an operating circuit for said second timing device including a front contact of said stick relay.

11. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located adjacent the intersection, a first time measuring device comprising a plurality of individual timing units each of which includes a thermal relay and a stick relay, circuit means controlled, by a train in traveling a fixed distance in approaching the intersection for successively operating said timing units, means for maintaining the stick relays of said units e'nergized, a second time measuring device comprising a plurality of individual timing units one for each unit of said first time measuring device, means controlled jointly by a train when it has traveled said fixed distance and by the energized stick relays for successively operating the timing units of said second device to effect the suc cessive release of said stick relays, and a control circuit for said signal including back contacts of said stick relays.

12. In combination, two adjoining sections of railway track, a series of timing relays, means for successively operating relays of said series while a vehicle occupies the first of said two sections, a chain of normally deenergized stick relays successively energized over circuits closed by the energized timing relays of said series, a stick circuit for each relay of the chain adapted to retain its relay energized when once picked up, a second series of timing relays, control circuits for the relays of said second series prepared by the successive pick up of said stick relays, control means rendered effective as the vehicle enters the second of said two sections to suecessively operate the timing relays of said second series to successively effect the release of the energized stick relays, and a signal circuit completed jointly by said stick relays in their released position and by said control means.

13. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, control means for starting the operation of said signalas a train reaches a fixed point in said stretch, a stick relay adapted when energized to prevent the control of said signal by said control means, a timing device arranged to complete an energizing circuit for said stick relay a predetermined time after a train enters said stretch, a second timing device including normally closed contacts and placed under control of said control means by said stick relay, and a stick circuit for said stick relay including said normally closed contacts of the second timing device.

14. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, control means for starting the operation of said signal as a train reaches a fixed point in said stretch, a first stick relay adapted when energized to prevent operation of said signal by said control means, a timing device arranged to complete an energizing circuit for said first stick relay a predetermined time after a train enters the stretch, a second stick relay adapted when energized to prevent the control of said signal by said control means and by said first stick relay, a second timing device set into operation in response to the energization of said first stick relay and arranged to complete an energizing circuit for said second stick relay a predetermined time after the operation of said first stick relay, a third timing device including a normally closed contact and placed under control mally closed contact and placed under control of said control means by the release of said first stick relay, and a stick circuit for said second stick relay including said normally closed contact of the fourth timing device.

15. In combination, a stretch of railway track divided into a measuring and an operating section each equipped with a track relay, said operating section being intersected by a highway, a highway crossing signal at the intersection, a chain of relays, a pair of inter-controlled relays set into operation by the track relay of the measuring section when a train approaching the intersection enters the measuring section, an auxiliary relay cooperating with said pair to sequentially energize the relays of said chain; circuits for sticking up the energized relays of said chain, said circuits excluding contacts of said pair of relays; a second pair of inter-controlled relays cooperating with said auxiliary relay and set into operation by the track relay of said operating section, means controlled by the track relay of said operating section for at the same time stopping the operation of said first pair of relays, means controlled by said second pair of relays and by said auxiliary relay to successively interrupt the stick circuits of the energized relays of said chain, and an operating circuit for said signal closed when the track relay of said operating section and all relays of said chain are in their released position.

16. In combination, a stretch of railway track divided into a measuring and an operating section each equipped with a track circuit including a track relay, the operating section being intersected by a highway, a highway crossing signal at the intersection, a control circuit for said signal open at a given point, means controlled by the track relay of said measuring section for measuring the time consumed by a train while in said measuring section and prior to its entry into said operating section and for opening a second point in said control circuit if a predetermined minimum time expires before the train enters the operating section, means controlled by the track relay of the operating section for closing said given point in said control circuit, other means set into operation by the entry of the train into the operating section for closing said second point in said control circuit to start operation of the signal, and other operating circuits for said signal closed by the track relay of the operating section and opened by said means to prevent the immediate operation of said signal if the time consumed in said measuring section exceeds said predetermined minimum.

17. In combination, a stretch of railway track divided into a measuring and an operating section each equipped with a track circuit including a track relay, the operating section being intersected by a highway, a highway crossing signal at the intersection, a control circuit for said signal open at a'given point, means controlled by the track relay of the measuring section for measuring the time consumed by a train while in said measuring section and prior to its entry into said operating section and for opening a second point in said control circuit if a predetermined minimum time expires before the train enters the operating section, means controlled by the track relay of the operating section for closing said given point in said control circuit, other means setinto operation by the entry of the train into the operating section for closing said second point in said control circuit to start operation of the signal after the expiration of a time period, a second operating circuit for said signal closed by the track relay of the operating section, and means included in circuit with the means set into operation by the entry of the train into the operating section for rendering said second operating circuit inefiectivev 18. In combination, a stretch of railway track divided into a measuring and an operating section, each equipped with a track circuit including a track relay, the operating section being intersected by a highway, a highway crossing signal at the intersection, a control circuit for said signal open at a given point, means controlled by the track relay of a measuring sectionfor measuring the time consumed by atrain While in said measuring section and prior to its entry into said operating section and for opening a second point in said control circuit if a predetermined minimum time expires before the train enters the operating section, means controlled by the track relay of the operating section for closing said given point in said control circuit, other means set into operation by the entry of the train into the operating section for closing said second point in said control circuit to'start operation of the signal after the expiration of a time period, an

emergency circuit for operating said signal controlled by the track relay of the operating section and including a contact immediately opened by the means set into operation by the entry of the-train'into the operating section, whereby it said last-named means fails to respond when the train enters'said' operating section said lastnamed contact will render'saidemergency circuit eiTective for operating said signal.

19. In combination, a stretch of railway track divided into track relay equipped measuring and operating sections, the latter'of which is intersected by a highway, at highway signal at the intersection, a chain of relays, means set into operation by the track relay of the measuring section for energizing a variable number of the relays of said chain depending on the time such measuring section is occupied prior to the entry of the train into the operating section, means controlled by the track relay of the operating section to prevent any relays of said chain which remain deenergized from being picked up, means also set into operation by the track relay of the operating section to effect the release of the energized relays of the chain one at a time, and

means for starting the operation of said signal chain becomes released.

20. In combination, a stretch of railway track divided into track relay equipped measuring and operating sections, the latter of which is intersected by a highway, a highway signal at the intersection, a chain of relays, means set into operation by the track relay of the measuring section for energizing a variable number of the relays of said chain depending on the time such measuring section is occupied prior to the entry of the train into the operating section, means controlled by the track relay of the operating section to prevent any relays of said chain which remain deenergized from being picked up, means also. set into operation by the track relay of the operating section to effect the release of the energized relays of the chain one at a time, and

signal when and only when the track relay of the operating section and certain relays of said chain are in their released position.

21. In combination, two successive sections of railway track, a highway intersecting said track adjacent the exit end of the second section, a highway signal, a track circuit for each section including a track relay, a chain of relays, means controlledby the track relay of the first section for initiating the sequential operation of the re- .lays of said chain, means controlled by the track 'relay of the second section for stopping the operation initiated by the track relay of the first section and for starting the sequential release of the operated relays of the chain, means also controlled by the track relay of the second section for starting the operation of said signal, and means for delaying the operation of said signal for a period determined by the extent to which the chain of relays is operated and the time required to effect their release.

22. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a chain of relays, timing means, means controlled by a train approaching the intersection toinitiate operation of said timing means in response to the entry of the train into a first portion of the stretch, means controlled by said timing means for energizing a variable number of the relays of said chain in accordance with the time consumed by the train while occupying said first portion of the stretch prior to its entry into a second portion of the stretch, other timing means associated with said chain of relays and eflfective when set into operation to release the relays one at a time at definite intervals apart, means for stopping the operation of said first mentioned timing means and .tor starting the operation of said other timing means when the train enters said second portion of the stretch, and means for setting the signal into operation when all of the relays of said chain have been released.

23. In combination, a stretch of railway track divided into measuring and operating sections, the latter of which is intersected by a highway, a track circuit for each of said sections including a track relay, a highway crossing signal at the intersection, a chain of relays, means set into operation by the track relay of the measuring section for energizing one at a time a variable number of the relays of said chain depending on the time such measuring section is occupied by a train prior to the entry of the train into the operating section, means set into operation by the track relay of the operating section to efiect the release of the energized relays of the chain one at a time at stated intervals apart, and means effective to start the operation of said signal when the track relay of the operating section and the relays of said chain are all in their released position.

24. In combination, a forward section and a rear section of railway track, a highway inter- I

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