US2174620A - Apparatus for the control of highway crossing signals - Google Patents

Description

Oct. 3, 1939. P. H. CRAGO 2,174,620

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Filed April 30, 1938 3 Sheets-Sheet 1 C012 l aczozar Fig.1.

Con IZJOZOPJ H INVENTOR 78 1- Paul Fly. 2.

H16 ATTORNEY Oct. 3, 1939. P. H. CRAGO 2,174,520

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Filed April 30, 1938 {5 Sheets-Sheet 2 Coniacz apj' Trolley ('012 z aezozm H C012 za INVENTOR [06 HIS ATTORNEY Pauli] ago Oct. 3, 1939. P. H. CRAGO 0 APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Filed April 50, 1938 3 Sheets-Sheet 3 Trolley Con zaozonr H Trolley C012 iaazon C7 6'5 10 1 lNVEINTOR H15 ATTORNEY Patented Oct. 3, 1939 N I'TED S TATES PATENT OFFICE APPARATUS FOR THE CONTROL OF HIGH- WAYCROSSING SIGNALS Application April 30, 1938, Serial No. 205,301

13 Claims.

My invention relates to apparatus for the con trol of highway crossing signals, and more particularly to apparatus for the control of highway crossing signals for electric railways.

A feature of my invention is the provision of novel and improved highway crossing signal control apparatus wherewitha loss-of protection due to .a temporaryffailure of power is avoided. Other features and advantages of my invention will L appear as the specification progresses.

I shall describe several forms of apparatus embodying my invention, and shall then point out the .-novel features thereof in claims.

In the accompanying drawings, Figs. .1, 2, 3, 4

15 and 5are diagrammatic views respectively of five different forms .of apparatus which embody my invention. Similar reference characters refer to similar parts in-eachof theseveral views.

Referring to Fig. 1, the reference characters la and lb designate the track rails of a stretch of single track electric railway which is provided with a propulsion current supply conductor 2, such :as-a trolley wire or third rail, adaptable to contact by -a suitable -train carried current collecting device, such as a trolley wheel or third rail shoe .not shown. In accordance with usual practice, the conductor 2, when a trolley wire, is supported substantially 'above the center line of the track at the necessary height. To aid in de- 30 scribing my invention, I shall assume the conduct-or 2 to be the usual trolley wire. In Fig. 1, as well as in the other drawings, the conductor 2 is illustrated at one side of the track rails for the sake of clarity. It'will also be understood, of course, that conductor 2 is connected with one terminal of a source of propulsion current, such as a generator not shown, and the track rails serve :as .the return path for "the propulsion -.cur rent.

40 This stretch .of railway of Fig. =1 'is intersected by a highwayI-I, adjacent which a highway crossing signal S is located. The type of highway crossing signal is immaterial, and as here provided the signal S comprises a green light G and 45 two red lights R and IR, the green light G being normally illuminated to indicate a clear signal when no railway .trafiic isapproaching the intersection, and the red lights R and IR being alternately and periodically illuminated to indicate 0 stop to highway users when .a train or car is approaching the intersection on .the railway. The

signal .S is positioned to be displayed to highway trafiic approaching the intersection from one direction. In practicing my invention, a second signal similar to signal S would be located at the intersection and positioned to be displayed to highway trafiic approaching the intersection from the other direction. This second signal is not shown for the sake of simplicity since its control would be the same as that of signal S, the control of signal S being fully described hereinafter.

Four trafiic governed devices or contactors are associated with this stretch of railway at selected points. These contactors are preferably alike, and in this instance their construction is that of standard practice for trolley contactors. As viewed in Fig. 1, the contactors Cl and C2 are positioned at selected points to the left and right, respectively, of the intersection. The distance the contactors Cl and C2 are located from the highway is in each case such as to provide satisfactory warning operation of the signal S in response to railway traffic approaching the intersection in the respective directions. To provide the so-called overlap control for the signal S, a contactor C3 is positioned adjacent the intersection on the side opposite the contactor Cl and a contactor C4 is positioned adjacentthe intersection on the side opposite the contactor C2. In other Words, a car approaching the intersection from the left, as viewed in l, initiates the warning operation of signal S in passing the contactor Cl, and the warning operation is discontinued when the car passes over the highway and operates the contactor C3. A car approaching the intersection from the right initiates the warning operation of the signal in passing the contactor C2, and the warning operation is discontinued when the car passes over the intersectionand operates the contactor C4.

Looking at contactor CI, for example, it comprises two contact members 3 and 8 which are juxtapositioned with contact member 3 more re mote from the intersection. The contact mem- 4 bers 3 and 9 are each spaced from the conductor 2 to be normally free from contact therewith. A trolley wheel of a car or vehicle bridges between the conductor 2 and the members 3 and 9 so that current from conductor 2 is applied to the mem hem-current being applied first to member 3 and then to member 9 when a car approaches the intersection, the trolley wheel engaging the member 9 before it leaves the member 3. For a car receding from the intersection, that is, moving from right to left in Fig. 1, current is first applied to member 9 and then to member 3 of the contactor CI. In a similar manner, the contactor 02 comprises two .juxtapositioned contact members 5 and I I, the member 5 being more remote from the intersection so that a trolley wheel of a car approaching the intersection applies current first to member 5 and then to member H, but a car receding from the intersection causes current to be applied first to member ii and then to member 5. Again, the contactor C3 comprises two contact members Zii and 36, and the contactor C l comprises two contact members 22 and current being successively applied to the two contact members of contactors C3 and Cd in accordance with the direction in which a trolley wheel passes thereover in the manner similar to that described for contactors Cl and C2. The contactcrs C3 and C4 are located on opposite sides of the highway and hence are spaced apart at least the distance equal to the width of the highway.

It will be understood, of course, that my invention is not limited to trolley contactors. The important feature of these contactors so far as my present invention is concerned is the fact that each comprises two contact members to which current is supplied successively and momentarily in response to a car passing thereover, the order in which current is supplied to the two contact members being in accordance with the direction of the passing car. For example, in railways other than electric railways, the contact mem bers 3 and 9 of contact Cl could be actuated by the leading wheel of a passing train, and the source of current could be any suitable wayside source.

To distinguish between cars approaching the intersection and cars receding from the intersection, a first directional device is associated with the first and second contactors CI and C2, and a second directional device is associated with the third and fourth contactors C3 and C4. These directional devices may take different forms, several being well known. As provided in Fig. 1, the first directional device comprises a first relay NI and a second relay N2, each of which when energized is effective to prevent the other relay from being energized. Looking at relay NI, an energizing or pick-up circuit extends from contact member 3 of contactor CI and wire 4 in multiple with contact member 5 of contactor C2 and line wire 5, thence over wire l5, back contact 'I of relay N2, winding of relay NI, resistor RI and wire 8 to the track rail lb. A stick circuit for relay NI includes contact member 9 of contactor CI and wire Ill in multiple with contact member II of contactor C2 and line wire I2, thence over wire i3, front contact l4 and winding of relay NI, resistor RE, wire 8 and to track rail ii). The energizing or pick-up circuit for relay N2 consists of the same elements as the stick circuit for relay NI up to wire it, thence over back contact it of relay NI, winding of relay N2, resistor RI, wire 8 and to the track rail Ib. A stick circuit for relay N2 includes the previously traced pick-up circuit for relay Nl up to wire l5, thence over front contact I? and winding of relay N2, resistor RI, wire 8 and to the track rail lb. With relay Ni picked up, closing front contact I8, a re sister R2 is connected across the winding of the relay to form a snubbing circuit to provide a slow release period for the relay. Likewise, with relay N2 picked up, closing front contact I 9, the resistor R2 is connected across the winding of relay NZ to provide the relay N2 with a slow release period. It follows that when a car approaches the intersection from the left and operates the contactor Cl by engaging contact member 3, or approaches the intersection from. the right and opcrates contactor C2 by engaging contact member 5, a first impulse of current is supplied from conductor 2 to the relay NI to pick up the relay NI. Then, when the car engages contact member 9 or contact member I I, as the case may be, the relay Ni is still supplied with current over its stick circuit, the relay NI being held picked up for its slow release period subsequent to such energization by virtue of the associated snubbing circuit. The relay N2 is not affected by a car approaching the intersection from either direction, since its circuit is held open at back contact I6 of relay Ni. When a car is receding from the intersection to the left and engages contact member 9 of contactor CI first, or is receding from the intersection to the right and engages contact member I I of contactor C2 first, a first impulse of current is supplied from conductor 2 to the relay N2, and relay N2 is picked up. Then current is supplied to relay N2 over its stick circuit when the car engages contact member 3 or contact member 5, as the case may be. The relay NI is not affected by a car receding from the intersection because the circuit for relay NI is held open at back contact 'l of relay N2.

The second directional device, associated with the contactors C3 and C4, comprises two relays N5 and N l, each of which is effective when picked to prevent the other relay from being energized, and which relays are controlled over pickup and stick circuits similar to the circuits described for relays Ni and N2 of the first directional device. When a car moving from left to right passes over the intersection and engages contact member 29 of contactor C3, or when a car moving from right to left passes over the intersection and engages contact member 22 of contactor CA, a first impulse of current is supplied from conductor 2 through contact member 20 and wire 2|, or through contact member 22 and wire 23, as the case may be, wire 24, back contact 25 of relay N4, winding of relay N3, resistor R3. wires 23 and 8, and track rail lb, and relay N3 is picked up. With relay N3 picked up, a second impulse is supplied to the relay over its stick circuit when the member 36 of contactor C3 is engaged by the car moving to the left, or when the member 28 of contactor C4 is engaged by the car moving to the right. The stick circuit for relay N3 involves member 36 and wire 21 in multiple with member 28 and wire 29, wire 30, front contact 3i and winding of relay N3, resistor R3, wires 26 and 8, and track rail lb. With relay N3 picked up, closing front contact 34, a resistor R4 is connected across the winding of relay N3 to provide the relay with a snubbing circuit so that the relay is slow releasing in character.

A pick-up circuit for the relay N4 includes the same elements as the stick circuit for relay N3 up to wire 3!); thence it extends over back contact 32 of relay N3, winding of relay N4, resistor R3, wires 26 and 8, and the track rail lb. The stick circuit for relay Nd includes the same elements as the pick-up circuit for relay N3 up to wire 24, thence over front contact 33 and winding of relay N4, resistor R3, wires 26 and 8, and track rail lb. The resistor R4 is connected across the winding of relay N l over front contact 35 of relay N4 to provide this relay with a slow release characteristic. It is to be seen, therefore, that when a car approaches the intersection from the left and passes over the contactor C4, or approaches the intersection from the right and passes over the contactor 03, a first impulse of current is supplied to the winding of relay N4 as the trolley wheel of the car engages contact member 28 or contact member 35, as the case may be, and a second impulse of current is supplied to the :relay N4 over itssstick circuit as the trolley wheel engages the contact member .22 or contact member 20. With relay N4 picked up in response to a car approaching the intersection, the relay N3 is prevented from being energizeddue to the fact that the circuit for relay N3 is held open at back con.- tact 2.5 of relay .Nli. The manner whereby these two directional devices control the highway crossing signal S will appear hereinafter.

The immediate control of signal S is effected by a polarized relay HR, which relay is in turn controlled by the two directional devices, relay HR being energized at one polarity when a train is approaching the intersection and being energized at the opposite polarity when the train is receding from the intersection. The-relay HR is provided with .a normal energizing winding NW and a reverse energizing winding RW, the arrangement being such that when current is supplied to the normal winding NW the polar contact members 37 and 38 of the relay are operated to the left-hand position, .as viewed in Fig. 1. When current is supplied to the reverse winding RW, the relay HR is energized to move its polar contact members 3! and 3.8 tothe right-hand position to engage reverse polar contacts .39 and 48, respectively. The polarized relay HR is preferably characterized by the fact that the stroke of its polarized armature will be completed if energy is applied to either winding for a long enough interval toopen the polar contacts in the last position. In other words, when an impulse of current is supplied to winding R-W or NWfor an interval long enough to move the polarized armature from its last position, :the armature moves to its other extreme position although the energizing current ceases. A relay which may be made to operate in the manner just described is disclosed and claimed in Letters Patent of the United States No. 1,790,671, granted to Branko Lazich on February 3, -1'93'1, 'for Electrical relays. In order to cause the relay :to operate in the intended manner it is only necessary to provide the relay cores with an additional winding similar to that shown in the patent as will be readily understood by those skilled in the art.

An energizing circuit for relay HR can be traced from conductor 2 over wire-4 l, front contact 42 of relay Nl, wire 43, reverse winding RW, a resistor R5, wires 44, 26 and 8, and to the track rail lb. Consequently, when =relay N1 is picked up for a brief interval in response to the contactor Cl or C2 being operated by a car approaching the intersection in the manner explained hereinbefore, the relay HR is supplied with current which flows in the winding :RW of :the relay; and the polar contact members 3-1 and 38 are operated to engage the respective reverse polar contacts 39 and 4!].

A holding circuit which is efiective to supply current to winding RW is provided so that relay HR, once operated to its reverse position, is effectively energized .to pickup its neutral armature. This holding circuit involves wire 45 connected with conductor 2, reverse polar contacts 3840 and 31-38 in series, wire 46, back contacts 41 and 38 of relay N3 in series, wires 49 and 43, winding RW, resistor R5, wires 44, 2E and 8, and the track rail lb. It follows that when current is momentarily supplied to the Winding RW of relay HR in response to a car approaching the in tersectionxto pickup relay N l, the polarized ar-' mature'ofTelayI-I'R is :moved to its reverse positionan-d the relay HR is retained energized at its reverse :position and its ineutral armature is picked up by virtue of its holding circuit, which holding circuit includes back contacts 4.! and 48 of the relay N3 :of the second directional device. It Will be understood, of course, that theimpulse of current supplied to winding RW over the first traced energizing circuit, including front contact 42 of relay :Nl, maybe of .sufiicient duration to cause relay HR to pick up its neutral armature, but this impulse of current need be only of sufficient duration to move the polar contact members '31 and 3.8 .of the relay away from their normal position, the polar contact members 31 and 38 completing their reverse movement by virtue of the characteristics of the relay, and the holding circuit being effective to energize the relay to operate its neutral armature.

Another energizing circuit for "relay HR can be traced from conductor 2, wire 45, reverse polar contacts 38-46 and 3"l'39 in series, wire 46, front contacts-66 andfi'l of relay'N3 in series, wire 68, normal winding NW, resistor R5, wires 44, 26 and v8, and to the track rail lb. Consequently, with the relay HR in its reverse position and the relay N3 of the second directional device picked up in the manner pointed out hereinbefore, an impulse of current is supplied 3130 the Winding NW to restore to relay 'HRito its normal position.

The lamp G of signal S is-controlled over a back neutral contact of relay HR, and the lamps R andlR of signal S are controlled over front neutralcontactsof relay HR through the medium of a flasher relay FR, which flasher relay may be of any of the well-known constructions. It is deemed sufi'lcien't for this application to point out that the contact member 56 of relay FR is biased to a mid position, that is, the position illustratedby the solid line in Fig. 1, and is operated between two extreme positions, illustrated by dotted lines, at a predetermined frequency of, say, 30 times per minute when the winding of the relay FR is'energized. As here shown, the contact member 56 engages a contact 51 at both its mid and left-hand positions and engages a contact 58 at its right-hand position. For illuminating the lamp G, current is supplied from conduc'tor 2 over wire 45, four back neutral contacts 50', 5|, 52 and 53 of relay HR in series, a resistor R6, wire 54, lamp G, wires 55 and 8, and to the rail lb. With relay HR picked up, closing its front neutral contacts, current is supplied from conductor 2 over wire 45, front neutral contacts 59, 60, SI and 62 in series. wire 63, a resistor R1, winding of flasher relay FR, wires 44, 26 and. 8, and to track rail lb, and the flasher relay FR is operated. During each interval, the contact 56-51 of flasher relay FR is closed, the lamp IR is short-circuited, and the lamp R is illuminated by current flowing over the same circuit traced for relay FR up to wire 53, and thence over a resistor R8, contact 565'l, wire 64, lamp R and wires 55 and 8 to the track rail l b. During each interval the contact 5658 of relay FR is closed, the lamp R is short-circuited and the lamp IR is illuminated by current fiowing from wire 63 over resistor R8, wire '65, lamp IR, wire 64, contact 5658, wires 44, 26 and 8, and to the rail lb.

In describing the-operation of the apparatus of Fig. -1, I shall consider the operating steps effected in response to a car moving from left to right. At the start, the lamp G of signal S is illuminated by current supplied over the back contact 53 of relay HR. The trolley wheel of the car successively engages the contact members 3 and 9 of contactor CI, and the relay Ni is energized for a brief interval, closing its front contact 52. The closing of front contact 42 causes current to be supplied to the reverse winding RW of relay HR, and the relay is operated to its reverse position, closing reverse polar contacts 31-49 and 3840. Relay HR is retained energized in its reverse position over its holding circuit subsequent to the time the car passes the contactor Cl, so that the neutral armature of relay HR is picked up, opening the circuit for lamp G and closing at its front contacts the circuit for supplying current to the flasher relay FR and in turn to the lamps R and IR of signal S. As the car passes the contactor C 3 in approaching the intersection, the relay N4 is picked up for an interval to prevent operation of relay N3, so that the relay HR remains energized to operate the lamps R and IR of signal S while the car passes over the intersection. The car, after passing over the intersection and receding from the crossing, successively engages the members 20 and 36 of contactor C3, so that the relay N3 is picked up for a brief interval, and relay N3 on picking up opens the holding circuit for relay HR and closes the energizing circuit to winding NW of relay HR. Current supplied to the normal winding NW causes the polarized armature of relay HR to be moved back to its normal position where the reverse polar contacts are open, and hence, when the car passes the contactor C3, the relay HR is deenergized and releases its neutral armature. With relay HR deenergized and its neutral armature released, the lamps R and [R are extinguished and the lamp G is again illuminated. This car moving from left to right engages first the contact member H and then the contact member of the contactor C2, and the relay N2 of the first directional device is picked up to prevent operation of the relay NI, with the result that the relay HR, and in turn the signal S, are not affected by the car receding from the intersection.

A car moving from right to left, on passing contactor C2 engages contact member 5 and then contact member II, so that relay N! is picked up, closing front contact 42. Closing of front contact 42 causes current to be supplied to winding RW, as previously described, and relay HR is operated to close its reverse polar contacts 3139 and 3849. Relay HR is retained energized at its reverse position by virtue of its holding circuit, so that its neutral armature is picked up and the lamp G is extinguished and the lamps R and IR are flashed to warn the highway users of the approach of the car. This car engages contact members 35 and 29 of contactor C3 in the order named, and relay N4 is picked up to prevent operation of relay N3, and the operation of the signal S is continued while the train passes over the intersection. When the car recedes from the crossing, it engages contact members 22 and 28 of contactor C4 in the order named, and the relay N3 is picked up for an interval to open the holding circuit of relay HR and to close the energizing circuit through the normal winding NW. With relay HR thus restored to its normal position, its neutral armature is released so that the operation of the lamps R and lR is stopped and the lamp G is again illuminated. The car moving to the left away from the crossing engages the contact members 9 and 3 of contactor CI in the order named, and relay N2 is picked up to prevent operation of relay NI.

It should be pointed out that in the event a car moving from left to right passes contactor CI to operate the relay HR to its reverse position and then there is a temporary failure of power to the conductor 2 while the car is between contactor Cl and the intersection, the relay HR is deenergized during the interval of power failure, but relay HR is at once reenergized and picked up over its holding circuit and operation of the signal S is restored as soon as power is restored to conductor 2. A similar action for relay HR is effected in the event of a temporary loss of power while a car moving from right to left approaches the intersection. The resistor R5 interposed in series with the windings RW and NW is relatively large and thereby reduces the time constant of the circuit including these windings, with the result that a relatively rapid operation of the polarized relay is eifected. Furthermore, the apparatus is restored to its normal position as soon as a car moving from left to right passes the contactor C3, and a second and following car passing the contactor C! will operate the signal S the same as the first car. Likewise, the apparatus is conditioned to operate for a second car moving from right to left, as soon as the first car passes the contactor 09'.

In Fig. 2 the track rails la and lb of a single track electric railway are intersected by a highway H, at which a highway crossing signal S is located, the same as in Fig. 1. The contactors Cl and C2 are located similarly to the contactors Cl and C2 of Fig. 1, and these contactors operate pick-up and stick circuits for the relays Ni and N2 of the first directional device the same as described in Fig. 1 except for the fact that a resistor R9 is permanently connected across the winding of relay NI and. a resistor RIB is permanently connected across the winding of relay N2 to provide these relays with desirable operating characteristics.

In Fig. 2 a contactor C5 having a single contact member 69 is located preferably at the in tersection and controls a relay N5 over a simple circuit including member 69, winding of relay N5, a resistor RH and wire 19 to the track rail lb. Hence, relay N5 is momentarily energized and picked up whenever the trolley wheel of a car engages the member 69, irrespective of the direction in which the car is moving. It is to be noted that the contact member 69 of contactor C5 would be somewhat greater in length than the contact members of the other contactors.

The polarized relay HR of Fig. 2 is the same as in Fig. 1, and current is supplied to its reverse winding RW over a front contact 42 of relay NI for operating the relay to its reverse position. The holding circuit for relay HR of Fig. 2 extends from conductor 2, wires 4! and H, reverse polar contacts 3il-4IJ and 31-39 in series, back contacts 12 and 13 of relay N5 in series, wires 18 and 43, reverse winding RW, resistor R5, wires 14 and Hi, and to the rail lb. The energizing circuit including the normal winding NW of relay HR can be traced from conductor 2 over wires M and H, reverse polar contacts 38- 30 and 31-39, front contact 15 of relay N5, winding NW, a resistor Ri2, wires M and H1, and to the track rail lb. A resistor RlS is shown connected in shunt with the normal winding NW to avoid opening the full trolley voltage when the circuit including winding NW is interrupted at the polar contacts of the relay.

The relay HR of Fig. 2 controls the signal S in substantially the same manner as in Fig. 1. Normally, the lamp G is illuminated to display a clear signal to the highway users by virtue of a circuit extending from conductor 2 over wires 4i and H, resistor R6, back contact ":16 of relay HR, lam-p G' and wires 55 and TS) to the track rail lb.

Assuming a car approaches the intersection from the left, the relay N l is picked up for a brief interval due to the trolley wheel making contact successively with the members 3 and ii of the contactor Cl. Closing front contact d2 of relay Nl causes current to be supplied to the winding RW of relay HR so that relay HR is operated to its reverse position and the holding circuit for the relay closed at the reverse polar contacts 38-46- and 3 'l--39. With relay HR energized over its holding circuit, its neutral armature is picked up, opening back contact 56 interposed in the circuit for lamp G, and closing front contact 71 interposed in the circuit for the flasher relay FR and lamps R and IR. The circult for the flasher relay FR involves wires ll and ll, reverse polar contacts 33=ili and 3'l-3l, back contacts 12 and T3 of relay N5, wires I8 and 43, front contact ll, resistor R1, winding of relay FR, and wires 74 and 18- to the track rail lb. With relay FR operating, current is supplied alternately to the lamps R and ER, the same as described in Fig. 1. As the car is passing over the highway and itstrolley wheel engages contact member 69-of contactor C5, current is suppliedto relay N5, and the relay is picked up momentarily to open the back contacts l2 and Minterposedin the holding circuit for relay HR and to close front contact 75 interposed in the energizing circuit for the normal winding NW. This momentary energization of winding NW causes-the polar armature of relay HR to be operated toits normal position, with the result that the relay HR is deenergized and releases its neutral armature when the relay N5 releases. The relay FR and the lamps R and lR are now without current and the lamp G is again illuminated; This car moving to the right engages contact members H and 5 of contactor C2 in the order named, and relay N2 is picked up to prevent the operation of relay Nl. It is to be noted that the apparatus is restored to its normal position as soon as the car passes over the intersection, and hence the relay HR and the signal S are operated by a second or following car approaching the highway H from the left and operating the contactor CI.

The operation of the apparatus of Fig. 2 for a car moving from right to left over the intersection is substantially the same as for the car moving from left to right, and the operation effected by a car moving from right to left need not be described in detail.

In Fig. 2, it is clear that, in the event of a loss of propulsion current just after the relay HR is operated to its reverse position, the relay HR is deenergized during. the interval the propulsion current is interrupted and is reenergized over its holding circuit as soon as the propulsion power is restored to the conductor 2. That is to say, the directional control is not released in the event of a loss of power and the warning operation is reestablished as soon as power is restored.

Referring now to Fig. 3, a single track electric railway is intersected by a highway having a highway crossing signal S located at the intersection, and has associated therewith contactors Cl, C2 and C5, the same as in Fig. 2. In Fig. 3, the relays N l and N2 of the first directional control device are provided with pick-up and stick circuits controlled by the contactors Cl and C2, the same as in Fig. i except the contact member 89 of contactor C5 is connected by a wire as with the wire i2 so that relay N2 is momentarily energized when the trolley wheel of a car passing over the intersection engages the member 83", relay N2 being energized irrespective of the direction thecar moves over the intersection.

t is believed that the circuits and apparatus of Fig. 3 will be best understood by a description of the operation of the apparatus. Normally, the lamp is illuminated by current supplied from conductor 2 over wires 4| and 81, back contact of relay HR, resistor R6, lamp G, wires 55- and it, andto the'rail lb. A car approaching the intersection from the left successively engages members 3 and 9 of contactor Cl, and the relay N l is picked up for a brief interval. The closing of front contact 42 of relay N l causes current to be supplied to the reverse winding RW of relay HR the same as in the previous cases, and relay HR is operated to move its polarized armature to the reverse position Where its reverse polar contacts 31-39 and 38-40 are closed. In Fig. 3; a holding circuit for relay HR is provided whichextendsfrom conductor 2 over wires ll and 31, reverse polar contacts 38-40 and in series, wire 87, back contacts 88 and 89 of relay N2 in series, winding RW, resistor R5, wires '14- and lil, and to therail lb. Thus, the relay HR is operated to its reverse position, and its neutralarmature is picked up in response to the car passing over the contactor CI. The back contact 82 of relay HR is now open to remove current from lamp G, and the front contacts 33, 8d; 85 and 86 of relay HR are closed to complete a circuit for the flasher relay FR and the lamps R and IR, so that relay FR is operated and the lamps R and lR are flashed to provide a warning indication of the approach of the car to the intersection.

As the car passes over the intersection and its trolley wheel engages the contact member 69 of contactor 05, current is supplied to relay N2 and relay N2 is picked up for a brief interval. The picking up of'relay N2 opens back contacts 88 and 89 interposed in the holding circuit for relay HR and closes front contacts 90 and SI so that current is supplied to the winding NW, the circuit being the same as the holding circuit up to wire 8?, thence over front contacts '99 and 9| in series, winding NW, resistor R5, wires 14 and It, and to the rail lb. With the winding NW momentarily energized, the relay HR. operates its polar contact members 38 and 31 back to the'normal position, with the result that when the relay N2 is released the relay HR is without current and its neutral armature is released so that the lamps R and IR are extinguished and the lamp G is again illuminated. This car on receding from the intersection successively engages members ll and 5 of contactor C2 in the order named, and the relay N2 is picked up to prevent operation of the relay Nl.

A car moving from right to left inFig. 3 causes a corresponding operation of the apparatus, and this operation need not be described in detail. It should be noted that with the apparatus constructed as shown in Fig. 3, a temporary loss of power from conductor 2 after a car has passed over contactor CI or C2 in approaching the intersection will, of course, cause the relay HR to be cleenergized, but the relay HR is at once reenergized over its holding circuit and the warning operation of the signal S is restored when power is restored to conductor 2.

In Fig. 4, a single track electric railway is intersected by a highway H having a highway crossing signal located adjacent thereto the same as in the previous cases. The contactors Cl, C2 and C5 of Fig. 4 are disposed with respect to the highway the same as in Figs. 2 and 3. The polarized relay HR of Fig. 4 is operated directly by the contactors CI, C2 and C5 with directional control effected through the medium of a single neutral relay N6.

The apparatus of Fig. 4 can best be understood by a description of its operation. Normally, the lamp G of signal S is illuminated by current supplied from conductor 2 over wire 92, back contact 93 of relay HR, resistor R5, lamp G, wires 55 and I0, and to the track rail lb. A car appreaching the intersection from the left first engages the contact member 3 of contactor CI, and in so doing causes current to be supplied to the reverse winding RW of relay HR, the circuit involved including wires 4 and I5, back contact 94 of relay N6, wire 95, reverse winding RW, a resistor RM, wires I4 and I0, and track rail Ib. I have found that by proportioning the resistor RM and the winding RW so that the relay HR receives only its normal ampere-turn energization the time constant of the circuit is relatively low and operation of the polarized armature of relay HR in less than 0.05 second is effected. With the parts thus proportioned, the relay HR is energized to reverse its polar armature although the winding RW is energized but for the brief interval the contact member 3 is bridged by the trolley wheel. It will be recalled that relay HR is characterized by the fact that its' polar contact members, once started from their last position, will move to their other extreme position notwithstanding the energizing current ceases. With relay HR reversed, current is supplied over a holding circuit which in this case includes conductor 2, wire 92, reverse polar contact 96-41, reverse winding RW, resistor RI4, wires 14 and I9, and to the track rail lb, and

. relay HR is effectively energized to pick up its neutral armature. As the polarized armature of relay HR is reversed before the contact member 9 of contactor Cl is engaged by the trolley wheel, a possible circuit, to be later described, for energizing relay N6 is opened at the normal polar contact IIl5--I06 of relay HR. The opening of back contact 93 of relay HR extinguishes the lamp G, and the closing of front contacts 98, 99, Ill!) and IIlI causes current to be supplied to the flasher relay FR, which relay is operated to alternately flash the lamps R and IR in the manner described for Fig. 1.

This car on moving over the intersection to engage contact member 69 of contactor C5 causes current to be supplied to the winding NW, the circuit including wire I02, the reverse polar contact IIl3-Ill4 and a resistor RI5. The resistor RI5 and the winding NW are proportioned to provide an ampere-turn energization greater than that effected by the holding circuit energizing winding RW, and also to effect a relatively low time constant for the circuit. The polarized armature of relay HR is therefore returned to its normal position in response to the car engaging the contact member 69 of contactor C5. With relay HR restored to its normal position, its holding circuit is open at the reverse polar contact 96-91 and relay HR is deenergized to release its neutral armature subsequent to the car passing beyond the contactor C5. The lamps R and IR are now dark and the lamp G is illuminated. This car moving to the right next engages the contact member II of contactor C2, and current is supplied from conductor 2 through the contact member l I, wire I2, wire I91, normal polar contact Ill5-II16, wire I08, winding of relay NE, a resistor RIG, wire 10, and to the track rail Ib, and the relay N6 is picked up. Relay N6 is supplied with current over a stick circuit when the contact member 5 of contactor C2 is next engaged by the car moving away from the intersection, the stick circuit involved including wires 6 and I5, and front contact I25 of relay N6. It is to be seen, therefore, that no current is supplied to relay HR when the car moves over the contactor C2 in moving away from the intersection due to the directional con trol effected by relay NB. The operation of the apparatus of Fig. 4 for a car moving from the right to the left is correspondingly similar to that just described for the car moving from left to right, and further detailed description of the operation is unnecessary. It is to be noted, however, in connection with the apparatus of Fig. 4 that a loss of power to the conductor 2 deenergizes the relay HR, but relay HR is reenergized and the warning operation of signal S is reestablished immediately following the restoring of power to the conductor 2.

In the form of the invention disclosed in Fig. 5 the apparatus is the same as in Fig. 3 except that the polarized relay HR is normally energized over a holding circuit and the relay is picked up to close its front neutral contacts. To be explicit, current is normally supplied from conductor 2 over a holding circuit including wires 4i and 8!, normal polar contacts I09I I and Ill-H2 in series, wire H3, back contacts l I4 and I I of relay NI in series, wire H6, normal winding NW, resistor R5, wires I4 and Ill, and track rail lb. The closing of front Contact II'I of relay HR completes a circuit easily traced from lamp G, and lamp G is normally illuminated. On the assumption a car approaches the intersection from the left, the relay NI is picked up for an interval due to the successive impulses supplied when the trolley wheel engages contact members 3 and 9 of contactor CI. With relay NI picked up, opening back contacts I I4 and I I5, the holding circuit for relay HR is opened and a circuit is formed for winding RW at the front contacts H9 and I I8 of relay NI, so that current flows from conductor 2 over wires M and 81, normal polar contacts I[l9-I I0 and IIIII2, wire H3, front contacts H8 and H9, wire I29, reverse winding RW, resistor R5, wires I4 and "I0, and track rail lb. The polarized armature of relay HR is now operated to its reverse position so that when relay NI is released subsequent to the car passing over contactor CI the relay HR is deenergized to release its neutral armature. Opening of front contact H'I of relay HR extinguishes lamp G, and the closing of back contacts I2I, I22, I23 and I24 in series completes a circuit easily traced for supplying current to the flasher relay FR and in turn to the lamps R and IR. Contact of the trolley wheel with the member 69 of contactor C5 as the car passes over the intersection supplies current to relay N2 in the same manner as described for Fig; 3,.and. relay N2 ispicked up for a brief interval; An energizing circuit is now formed from conductor 2 over wires 4! and I26, front contact I27 of relay N2, wire H6, normal winding. NW, resistor R5, wires 14' and I0, and track rail lb, and the polarized armature of relay HR is operated'to itsnormal position to close the normal polar contacts I09I land I I'I-I I2. Relay HR is now energized over its holding circuit, with the result that the fiasher relay FR and lamps R and IR are deenergized and the lamp G isagain illuminated. As the car moves to the right and passes over the contactor C2, relay N2 is picked up in the same manner as described for Fig. 3, but relay HR is unaiTected by the current supplied to winding NW over front contact I21 since relay HR is now energized by its holding circuit. Consequently, the'signal S is not affected as this car moving to-the right recedes from the intersection; The operation of the apparatus of Fig. 5 for a car. moving from right to left is correspondingly similar to that just described for a* car moving from left to right, and further detailed description of the operation of the: apparatus is unnecessary.

Although I have herein shown and described only five 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.

Having thus described my invention, what I claim is:

l. Inv combination, a. railway track intersected by ahighway, a highway crossing signal located at the intersection; a first traffic controlled device located to one side of the intersection, a second traffic controlled. device located adjacent the intersection, a relay having apolar armature,

circuit means controlled by said first device to energiz said relay at one polarity when a vehicle passes the first device, other circuit means controlled by said second device to energize said relay at the otherpolarity when a vehicle passes the second device, a holding circuit including polar contacts of said; relay and controlled by a selected one of the devices to energize the relay at a selected polarity, and operating means governedloy the relay for'operating'the signal.

2. In combination, arailway track intersected by a highway, a highway crossing signal located at the intersection, a first trafiic controlled device located to one side of the intersection, a second trafiic controlled device located adjacent the intersection, a polarized relay normally conditioned with its polar armature at a. selected one of its positions, a first circuit operative while a vehicle is passing said first device to supply an impulse of current to energizethe relay at the polarity required to move the polar armature away from said selected position, a second circuit operative while a vehicle is passing said second device to supply an impulse of current to energize the relay at the polarity required to move the polar armature away from the position opposite said selected position, a holding circuit including a polar contact of the relay for at times energizing the relay to pick up its neutral armature, and operating means controlled by the neutral armature for operating the signal.

3. In combination, a railway track intersected by ahighway, a highway crossing signal located at the intersection, a first traflic controlled device located to one side of the intersection and including a pairofjuxtapositionedcontact members, a second trafiic controlled device located adjacent the intersection and including a contact member, a polarized relay having a normal energizing winding and a reverse energizing winding, directional means controlled by said pair of contact members when operated by a train approaching the intersection to supply an impulse of current to said reverse winding and to prevent such supply of current when operated by'a train receding from the intersection, a holding circuit including a selected one of the relay windings and a corresponding polar contact of the relay for at times energizing the relay to operate its neutral armature, other circuit means controlled by the contact member of said second device when operated by a train to supply an impulse of current to said-normal winding, and operatingmeans controlled by the neutral armature of the-relay for operating the signal.

4. In combination, a railway track intersected by a highway, a highway crossing signal located at the intersection, a first contactor located to one side of the intersection, a second contactor located adjacent the intersection, a polarized relay, a first circuit means controlled by said first contactor when operated by a car approaching the intersection to energize the relay at reverse polarity, a holding circuit including a reverse polar contact. of the relay to energize the relay at reverse polarity, a second circuit means controlled by said second contactor when operated by a car to effectively energize the relay at normal polarity, and operating means controlled by the neutral armature of the relay for operating the signal.

5. In combination, a railway track intersected by a highway, a highway crossing signal located at the intersection, a first contactor located to one side of the intersection, a second contactor located adjacent the intersection, a polarized relay having a normal energizing winding and a reverse energizing winding, a first circuit controlled by said first contactor operative to supply an impulse of current to said reverse winding when a car approaching the intersection passes said first contactor, a holding circuit for energizing the relay including said reverse winding and a reverse polar contact of the relay, a second circuit controlled by said second contactor operative to supply an impulse of current to said normal winding while a car passes said second contactor, and operating means controlled by the neutral armature of said relay for operating the signal.

6. In combination, a railway track intersected by a highway, a highway crossing signal located at the intersection, a first contactor located to one side of the intersection, a second contactor located adjacent the intersection, a polarized relay having a normal: energizing windin a reverse energizing. winding, a first circuit controlled by said first contactor operative to supply an impulse of current to said reverse winding when a car approaching the intersection passes said first contactor, a holding circuit for energizing the relay including said reverse winding and a reverse polar contact of the relay, other circuit means controlled by said second contactor operative while a car is passing said second contactor to open said holding circuit and to supply an impulse of current to said normal wind ing, and operating means controlled by the neu-' tral armature of said relay for operating the signal;

7. In combination, a railway track intersected by a highway, a highway crossing signal located at the intersection, a first traffic controlled device located on one side of the intersection and including two contact members disposed with one slightly more remote from the intersection than the other, a second trafiic controlled device located on the other side of the intersection and including two contact members disposed with one slightly more remote from the intersection than the other, an additional traffic controlled device located adjacent the intersection and including a contact member, directional means including a first and a second relay, circuit means including a back contact of the second relay to energize the first relay and made operative when the more remote member of either the first or the second device is engaged by a train, other circuit means including a back contact of the first relay to energize the second relay and made operative when the nearer member of either the first or the second device is engaged by a train, a polarized relay having a normal energizing winding and a reverse energizing winding, means including a front contact of said first relay to supply current to said reverse winding, a holding circuit for said polarized relay including a reverse polar contact and the reverse winding of the relay, means to open said holding circuit and to supply current to said normal winding and made operative when the member of said additional device is engaged by a train, and means including neutral contacts of said polarized relay for operating the signal.

8. In combination, a railway track intersected by a highway, a highway crossing signal at the intersection, a first pair of contact members located successively on one side of the intersection, a second pair of contact members located successively on the other side of the intersection, a third pair of contact members located successively adjacent the intersection on the side opposite said first pair, a fourth pair of contact members located successively adjacent the intersection on the side opposite said second pair, a first directional means comprising a first and a second relay each of which is effective when pick-ed up to prevent the other relay from being energized, a second directional means comprising a third and a fourth relay each of which is effective when picked up to prevent the other relay from being energized, means to connect said first relay with the member more remote from the intersection of each of said first and said second pair, means to connect the second relay with the member nearer the intersection of each of said first and said second pair, means to connect the third relay with the member nearer the intersection of each of said third and said fourth pair, means to connect the fourth relay with the member more remote from the intersection of each of said third and said fourth pair, a polarized relay having a normal and a reverse winding, means including a front contact of said first relay to supply current to said reverse winding, a holding circuit to supply current to said reverse winding including a reverse polar contact of the polarized relay and a back contact of said third relay, means including a front contact of the third relay to supply current to said normal winding, and operating means including neutral contacts of the polarized relay to operate the signal.

9. In combination, a railway track intersected by a highway, a highway crossing signal at the intersection, a first pair of contact members located successively on one side of the intersection, a second pair of contact members located successively on the other side of the intersection, an additional contact member located adjacent the intersection, directional means comprising a first and a second relay each of which is eifective when picked up to prevent the other relay from being energized, means to connect said first relay with the contact member more remote from the intersection of each of said first and said second pair, means to connect said second relay with the contact member nearer the intersection of each of said first and said second pair, another relay connected with said additional member, a polarized relay having a normal and a reverse winding, means including a front contact of said first relay to supply current to said reverse winding, a holding circuit to supply current to said reverse winding including a reverse polar contact of the polarized relay and a back contact of said other relay, means including a front contact of said other relay to supply current to said normal winding, and operating means including neutral contacts of the polarized relay to operate the signal 10. In combination, a railway track provided with a propulsion current conductor and intersected by a highway, a highway crossing signal at the intersection, a first contactor located to a one side of the intersection and a second contactor located adjacent the intersection and said contactors disposed for operation by the current collector of a passing vehicle, a polarized relay having a normal energizing winding and a reverse energizing winding, means governed by said first contactor when operated to supply current from said conductor to said reverse winding, a holding circuit for said polarized relay including the reverse winding and a reverse polar contact, means governed by said second contactor when operated to open said holding circuit and to supply current from said conductor to said normal winding, and means including neutral contacts of said polarized relay to govern said signal.

11. In combination, a railway track provided with a propulsion current conductor and intersected by a highway, a highway crossing signal at the intersection, a first contactor located to one side of the intersection and a second contactor located adjacent the intersection and said contactors disposed for operation by the current collector of a passing vehicle, a polarized relay having a normal energizing winding and a reverse energizing winding, means governed by said first contactor when operated to connect said reverse winding between said conductor and a track rail, a holding circuit to connect said reverse winding between said conductor and a track rail including a reverse polar contact of the relay and a normally closed contact, means governed by said second contactor when operated to open said normally closed contact and to connect said normal winding between said conductor and a track rail, and means including neutral contacts of the relay to operate the signal.

12. In combination, a railway track intersected by a highway, a highway crossing signal at the intersection, a first pair of contact members located successively on one side of the intersection, a second pair of contact members located successively on the other side of the intersection, anadditional contact member located adjacent the intersection, directional means comprising a first and a second relay each of which is effective when picked up to prevent the other relay from being energized, means to connect said first relay with the contact member more remote from the intersection of each of said first and said second pair, means to connect said second relay with the contact member nearer the intersection of each of said first and said second pair and to said additional contactor, a polarized relay having a normal and a reverse winding, means including a front contact of said first relay to supply current to said reverse winding, a holding circuit to supply current to said reverse winding including a reverse polar contact of the polarized relay and a back contact of said second relay, means including a front contact of said second relay to supply current to said normal Winding, and operating means including neutral contacts of the polarized relay to operate the signal.

13. In combination, a railway track intersected by a highway, a highway crossing signal located at the intersection, a pair of contactors located on one side of the intersection and arranged for successive operation by a train approaching the intersection, a third contactor located adjacent the intersection, a polarized relay having a reverse energizing winding and a normal energizing winding, directional means controlled by said pair of contactors when operated by a train approaching the intersection to supply an impulse of current to said reverse winding, a holding circuit for energizing the relay including said reverse winding and a reverse polar contact of the relay, circuit means controlled by said third contactor to supply an impulse of current to said normal winding when a train passes the contactor, and means including neutral contacts of the relay for controlling the signal.

PAUL H. CRAGO.

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