US2769901A - Railway switch controlling apparatus - Google Patents

Description

Nov. 6, 1956 E. DODD RAILWAY SWITCH CONTROLLINGAPPARATUS 2 Sheets-Sheet 1 Filed June 16, 1951 INVENTOR. Arthur E. Dodd 15 ATTORNEY Nov. 6, 1956 A. DODD RAILWAY SWITCH CONTROLLING APPARATUS 2 Sheets-Sheet 2 Filed June l6,- 1951 MEIE United States Patent RAILWAY SWITCH CONTROLLING APPARATUS Arthur E. Dodd, Edgewood, Pa., assignor to Westinghouse Air Brake Company, a corporation of Pennsylvania Application June 16, 1951, Serial No. 231,977

Claims. (Cl. 246-219) My invention relates to railway switch controlling apparatus. More particlularly, my invention relates to control apparatus for manually efi'ecting operation of a railway track switch from a remote point.

Railway switch operating mechanisms 'of the wellknown electropneumatic type are equipped with control elements designated as normal, reverse and lock control magnets. For manually effecting operation of a railway track switch operating mechanism of this type from a remote point, a polarized switch control relay, having a neutral armature and a'polar armature, is commonly employed. Traffic movements over the corresponding switch are governed by signals for the routes in which the switch is included.

A traflic responsive relay such, for example, as a track relay associated with the switch, is normally energized, but becomes deenergized in response to a train adjacent the switch, on a route in which the switch is included. A switch locking relay is controlled to be energized, .for closing a front contact, only if the traific responsive relay is energized, and only if each of the signals which directs traflic movements over the switch is controlled for displaying a stop indication.

It would obviously be unsafe for the switch to be moved from either of its extreme positions to the other while the associated switch locking relay is deenergized, either because of a train adjacent the switch on' a route in which the switch is included, or because a signal is controlled for displaying a proceed indication for directing a traflic movement to be made over the switch. Accordingly, in order to prevent movement of the switch from being manually effected from a remote control point while either of those conditions exists, it has been common practice to include a front contact of the switch locking relay in the normal and reverse control circuits for the polarized switch control relay. The polarized switch control relay therefore becomes deenergized in response to deenergization of the switch locking relay.

For a switch mechanism of the electropneumatic type to move a switch to the normal position, the normal control magnet and the lock control magnet for the switch mechanism must be energized. For such a switch mechanism to move the associated switch to the reverse position, the reverse control magnet and the lock control magnet must be energized. The normal and reverse switch control magnets are commonly energized by circuits which are controlled by only normal and reverse polar contacts, respectively, of the polarized switch control relay.

The lock control magnet is energized by a circuit which is completed when the polar contacts of the polarized switch control relay are moved out of correspondence with the position of the switch, that is, when the polar contacts of the polarized switch control relay are moved away from the normal position while the switch is in the normal position, or when the polar contacts of the polarized switch control relay are moved away from the reverse position while the switch is in the reverse position. Therefore, .upon the completition of each operation of the switch to one of its extreme positions, so that the position of the switch corresponds to the position of the polar contacts of the'polarized switch control relay, the lock control magnet will .become deenergized.

The lock control magnet is also controlled by a circuit controller operated in conjunction with the switch, so

that the lock control magnet will become energized if the switch should become misplaced from either of its extreme positions to some point between the two extreme positions. If the polar contacts of the polarized switch control relay are in the position which corresponds to the extreme position .of :the switch from which the switch has become misplaced, either the normal or the reverse control magnet will therefore also be energized, while the lock control magnet is energized because of misplacement of :the switch. The switch mechanism will then act 'to return the switch to the position from which it has been misplaced. This method of control is .known as .the restoring feature for an .electropneumatic switch mechanism.

It follows that, if the restoring feature is to be elfective for restoring a switch to an extreme position from which it has been misplaced while the polarized switch control relay is deenergized because of deenergization of the switch locking relay, the. polar contacts of the polarized switch control relay must remain closed, while ture in the position which it occupies when the polarized switch control relay becames deenergized.

An object of my invention is therefore the provision of a control arrangement, for an electropneumatic switch mechanism, which :embodies a polarized switch control relay having a polar armature which is mechanically locked in the normal or the reverse position, by a neutral armature in the deenergized position, while the polarized switch control relay is deenergized.

A feature of my invention for accomplishing this ob- V ject is the use of a polarized switch control relay having a neutral armature controlled by biased neutral means with a neutral winding for picking up the neutral armature only when currentof a given polarity is supplied to the neutral winding, and having means controlled by the neutral armature in the deenergized position for mechanically locking the polar armature of the polarized switch control relay in the normal or the reverse position to which it was last Previously operated in response to energization of the relay by current of normal or reverse polarity, respectively.

Another feature of my invention is the provision of a control circuit arrangement embodying only two line control conductors for controlling a polarized switch control relay, of the type in which a polar armature is mechanically locked by a neutral armature in the deenergized condition, for effecting operations of a switch mechanism for moving a corresponding switch to its normal and reverse extreme positions.

If a signal maintainer or other employee shouldremove a polarized switch control relay from the control circuit arrangement for a switch which is provided with an operating mechanism of the electropneumatic type, for example, and if the same relay or a similar relay is later Patented Nov. 6, 1.95.6

r 3 connected into the switch control circuit arrangement, the polar contacts of the relay, at the time of being thus connected, may not be in the same position as the polar contacts, of the relay which was removed, were occupying at the time of removal of the polarized switch control relay. If, at the time of such reconnection of the con-- trol circuit arrangement, the switch locking relay were deenergized, the polarized switch control relay would also remain deenergized, and therefore the switch might be operated to the wrong position, on account of the polar contacts of the polarized switch control relay, now connected in the control circuit arrangement, being in a different position than the polar contacts of the polarized switch control relay, which was removed, were occupying at the time it was removed from the switch control circuit arrangement.

Another object of my invention is therefore the provision of means for protecting against operation of a switch to a wrong position, when a polarized switch control relay is removed from a switch control circuit arrangement and is afterwards reconnected in the same switch control circuit arrangement or is replaced by a similar relay.

A feature of my invention for accomplishing this object is the provision of an auxiliary or second neutral armature in addition to the first neutral armature of the polarized switch control relay, and of means for retaining the auxiliary neutral armature in the picked-up position after the relay becomes deenergized, and also of means for rendering the retaining means inefiective, upon either removal of the polarized switch control relay from, or its replacement in, the switch control circuit arrangement, until after the polarized switch control relay has again been energized.

Another feature of my invention for accomplishing this object is the provision of means for opening the control circuit for the polarized switch control relay at the time of either removal of the polarized switch control relay from or its replacement in the control circuit arrangement for a switch.

Still another feature of my invention is the use of a front contact, operated by the auxiliary or second neutral armature, and a back contact operated by the first neutral armature, in the control circuits for the normal and reverse switch control magnets.

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

In the accompanying drawings, Fig. 1 is a diagrammatic view showingflone form of apparatus embodying my invention, in which a polarized switch control relay has a neutral armature controlled by a biased neutral device embodying a neutral winding for moving the neutral armature to an energized or picked-up position only while current of a given polarity is supplied to the neutral winding; in which a polar armature of the polarized switch control relay is mechanically locked, in its normal or its reverse position, by locking mechanism operated by the neutral armature, when the neutral armature is in a deenergized position; and in which the polarized switch control relay is manually controlled from a remote point by a line control circuit arrangement which requires only twolinc control conductors.

Fig. 2 is a diagrammatic view showing a modified form of the apparatus of Fig. 1, also embodying my invention, in which a polarized switch control relay embodies, in addition to a first neutral armature, also a second neutral armature which may be controlled by a first neutral winding or by a second or auxiliary neutral winding; in which retaining means is provided for keeping the second neutral armature in the energized or picked-up position after the polarized switch control relay becomes deenergized; in which means. is also provided for rendering the retaining means ineffective for keeping the second neutral armature in the picked-up position when the switch control relay is either removed from or returned to a given location; and in which means is also provided for deenergizing the switch control relay preparatory to its being removed from or returned to the given location.

Referring first to Fig. 1 of the drawings, a railway track switch, designated by the reference character W, is shown in a normal position in a route over a main track T. An auxiliary track, designated by the reference character t, is connected, by switch W in its reverse position, with main track T, in a second route.

Tracks T and t are divided by insulated joints 1 to form a switch section a-b. Section a-b is provided with trafiic responsive means or safety control means such, for example, as a track relay TR, connected across the rails adjacent one end of section ab, and energized by current from a suitable source such, for example, as a battery 2 connected across the rails adjacent the opposite end of section a-b.

A signal, designated by the reference character S, is shown for governing trafiic movements over a route which includes switch W. Signal S may be of any suitable design such, for example, as the well-known searchlight type.

Signal S may be controlled, in any suitable manner, for displaying a proceed indication for directing a traflic movement over a route which includes switch W, and therefore for also directing a traffic movement over switch W. As shown in the drawing, the control means for signal S includes a manually operable signal control lever SV which may be located at a remote point such, for example, as an interlocking tower or a dispatchers ofiice. Lever SV has a normal position n, and a control position to the left, as shown in the drawing. An energizing circuit for a signal control relay HR is controlled by means including a contact 3, of lever SV, which is closed while lever SV is in its f position. A circuit for controlling signal S to display a proceed indication is controlled by means including a contact 4 of relay HR.

Switch W is operable to a normal position, in which it is shown in the drawing, or to the opposite or reverse position, by a switch mechanism, designated by the reference character M, which may be of the well-known electropneumatic type having normal, reverse and lock control magnets, designated by the reference characters A, R and L, respectively.

A switch circuit controller, designated by the reference character WC, and comprising contacts 5 and 21, is operated in conjunction with switch W. Contact 5 is open while switch W is in either the normal or the reverse extreme position, but is closed while switch W is in any position between its normal and reverse extreme positions. Contact 21 is closed, in the normal position of switch W, in a first control circuit for controlling a switch indication relay designated by the reference character SS. Contact 21 is also closed, in the reverse position 'of switch W, in a second circuit for controlling switch indication relay SS.

Normal and reverse switch control magnets A and R, respectively, for switch W, are controlled by a polar contact 19, of a polarized switch control relay, designated by the reference character WR, in its normal and reverse positions, respectively.

Lock control magnet L is controlled by a circuit which includes contact 5 of switch circuit controller WC, and is also controlled by a branch circuit which includes contact 6 of switch indication relay SS.

Polarized switch control relay WR embodies a neutral armature bu and a polar armature p. A locking dog 7 is moved to an upper or a lower position by a member 8 which is in turn moved up or down by armature bu. In this way, locking dog 7 is moved out of, or into, engagement with a lock member 33 which is rigidly attached to armature 1. By this means, polar armature p is locked, in the normal or the reverse position to which it was last Operated, by neutral armature bu, while relay .WR'isdeenergized.

Qperation of polar armature .p to its normal and .reverse positions is effected by a polar control winding of relay WR, designated by the .referencecharacter P. Neutral armature bu is controlled by biased neutral means including a control winding BU of relay WR, so that armature bu will be moved to the energized or picked-up position, when control current passes through winding BU in the direction indicated by'the arrow, and will occupy the deenergized position, in which it is shown in the drawing, when control current passes through winding BU in the opposite direction, or when no current is passing through winding BU.

A manually operable switch controlling device, shown as alever WV, may be located in an interlocking tower or a dispatchers oflice. Lever WV has a normal position 11, in which it is shown in the drawing, and a reverse position r.

Current of normal or reverse polarity, according as lever WV is in its 11 position or its r position, is supplied over two line control conductors 14a and 17a of a line control circuit, for energizing windings BU and P of relay WR. Current for energizing winding P is also controlled by a contact 25, which is controlled by neutral armature bu, and which is closed only while armature bu is in the energized or picked-up position, and by a contact 15 of a switch locking relay, designated by the reference character LR. Current for energizing winding EU is controlled by polar contacts 16 and 17 of armature p, and by contact 15 of relay LR, and also by pole-changing contacts of lever WV.

Switch indication relay SS is controlled by a back contact 29 which is closed while neutral armature bu is in the deenergized position, and is also controlled by polar contact 22 of polar armature p, as well as by contact 21 of switch circuit controller WC. Indication means such, for example, as a lamp E, may be controlled by switch indication relay SS.

Switch locking relay LR is controlled by a front contact of track relay TR, and by a back contact of relay HR. Relay LR is therefore energized only while there is no train adjacent switch W on a route whichincludes switch W, and only while signal S is controlled to display a stop indication. When a train occupies section ab adjacent switch W, or when signal S for a route which includes switch W is controlled by relay HR to display a proceed indication for directing a trafiic movement over switch W, relay LR will be deenergized, and therefore the control circuits for relay WR will be open at contact 1-5 of relay LR.

Referring now to Fig. 2 of the drawings,the modified form of apparatus embodying my invention, as here shown, embodies all that'is shown in Fig. l, including the locking arrangement by means of whichthe neutral armature bu, controlled by winding BU, locks the polar armature p, which is controlled by winding P. In order to simplify the drawing, the detail showing of the locking arrangement is omitted in Fig. 2, but it is to be understood that this forms a part of the apparatus of Fig. 2, the same as it is shown in Fig. l, as indicated by the dash line 32 in Fig. 2.

In addition to the apparatus shown in Fig, l, the modified form of apparatus embodying my invention, as shown in Fig. 2, includes a second or auxiliary neutral armature ,1: controlled by means, including a third winding U of relay WR, which is not biased and is therefore responsive to current of either polarity .for moving armature uto the energized or picked-up position. A dog 9, pivoted at d, retains armature u in the energized position when relay WR becomes deenergized.

The base plate of relay WR, designated by the reference character in is locked into a given position or location on a mounting plate at by a manually operable latching device 11, the wedge-shaped lower end of which is forced by a spring g normally into locking engagement with a locking plate 11 which is rigidly connected with mounting plate x. While the lower end 10 of latching device It is in the lock position in locking plate 11, a contact 27 closes a contact 27a27b which is included in a control circuit ,for relay WR. Contact 27a-.27b may be insulated, by any suitable means, from spring g, latch h, dog 9, and locking plate 11.

When latching device 11 is manually moved upwardly out of locking engagement with locking plate 11, contact plate 2.7 compresses spring g, opens contact 27a-27b, and rotates dog 9, about the pivot u, out of engagement with armature u, so that dog 9 is rendered ineffective for retaining armature u in the energized or picked-up position. Armature u will therefore drop to the deenergized position, and will remain there until winding U again becomes energized. Contacts operated by armature u are included in the control circuits for relay SS and switch control magnets A, R and L.

The various circuits shown in the drawings may be supplied with energizing current from any suitable source such, for example, as a battery Q, shown in Fig. 2, having terminals designated by the reference characters B and N.

Having described, in general, the arrangement and control of the apparatus shown by the accompanying drawings, I shall now describe its operation in detail.

As shown by the drawings, all parts are in the normal condition, that is, switch W is in its normal position; signal S is controlled to display a stop indication; track section va-b is unoccupied, and therefore track relay TR is energized; each of the levers SV and WV is in its n position; winding BU is energized by current of normal polarity, which is opposite to the direction indicated by the arrow, and therefore armature bu is in the deenergized position, contact 25 of armature bu is open, and winding P is deenergized; relay HR, lock control magnet L, and reverse control magnet R are deenergized; relays SS and LR, normal control magnet A, and indication device E are energized; and winding U, shown in Fig. 2, is energized.

The circuit by which relay LR is energized passes from terminal B, through contacts 12 and 13 of relays TR and HR, respectively, and the winding of relay LR to terminal N.

As shown in Fig. 1, current is flowing through winding BU of relay WR, in the direction opposite to the arrow, by a circuit passing from terminal B, through contact 14 of lever WV, line conductor 14a, contact 15 of relay LR, contact 16 of armature p closed in the normal or left-hand position, winding BU, contact 17 of armature p closed in the left-hand position, line conductor 17a, and contact 18 of lever WV closed in the n position, to terminal N.

Switch control magnet A is energized by a circuit passing from terminal B, through contact 19 of armature p closed in the normal or left-hand position, and the winding of magnet A to terminal N.

Relay SS is energized by a circuit passing from terminal B, through contact 29 of armature bu, contact 21 of circuit controller WC closed in the normal position, contact 22 of polar armature p closed in the normal'position, and the winding of relay SS to terminal N. With relay SS energized, indication lamp E is energized by a circuit passing from terminal B, through contact 23 of relay SS, and lamp E to terminal N.

In the arrangement shown in Fig. 2, the circuit which is closed for winding EU is the same as in Fig. 1 except that it includes winding U in series with winding BU, and includes contact 27a-27b of latching device h. Winding U is therefore energized by the current which is passing through winding BU in the direction opposite to the arrow. Since winding U is responsive to current of either polarity, its contacts 29, 30 and 31 are .closed, and its armature u is inthe loclred-up position. The circuit shown in Fig. 2 by Which normal control magnet A is energized passes from terminal B, through contact 28 of armature bu, contact 29 of armature 11, contact 19 of armature p closed in the normal position, and the winding of magnet A to terminal N. As shown in Fig. 2, relay SS is energized by a circuit which is the same as the circuit previously traced for relay SS in Fig. 1, except that it includes also contact 30 of armature u.

I shall assume that a train moving from right to left, as shown in Fig. 1 of the drawings, is to proceed over switch W in the normal position. A leverman or dispatcher will therefore move lever SV to its 1 position, thereby closing its contact 3 and completing a circuit for energizing relay HR, this circuit passing from terminal B, through contact 3 of lever SV, and the winding of relay HR to terminal N. With relay HR energized, a circuit will be completed for controlling signal S to display a proceed indication, this circuit passing from terminal B, through contact 4 of relay HR, and the operating mechanism of signal S to terminal N. Relay HR, upon becoming energized, opens its contact 13, thereby deenergizing relay LR. When relay LR becomes deenergized, contact 15 of relay LR opens the circuit previously traced through winding BU of relay WR, and therefore relay WR is now deenergized.

I shall now assume that the train passes signal S onto section a-b, deenergizing relay TR. The circuit for relay LR will therefore now be opened at a second point, on account of contact 12 of relay TR being opened. Relay LR will therefore remain deenergized as long as either contact 12 of relay TR or contact 13 of relay HR is open. Relay WR will in turn remain deenergized as long as relay LR is deenergized. With armature bu in the deenergized position, dog 7 is in locking position with relation to lock member 33 which is attached to armature p. The polar contacts operated by armature p will therefore be locked closed in the normal position, and normal control magnet A will remain energized by its circuit previously traced through contact 19 of armature p closed in the normal position.

I shall next assume that the train has left section ab,

and that all parts of the apparatus are again in the normal condition as shown in Fig. 1 of the drawings, and that a leverman then moves lever WV to its r position for reversing switch W. Winding BU of relay WR will now be energized by current flowing, in the reverse direction indicated by the arrow, through a circuit passing from terminal B, through contact 24 of lever WV closed in the r position, conductor 17a, contact 17 of armature p closed in the normal position, winding BU, contact 16 of armature p closed in the normal position, contact 15 of relay LR, line control conductor 14a, and contact 26 of lever WV, to terminal N. Armature bu will therefore become raised to the energized position, opening its contact 20, and closing its contact 25.

Contact 20, upon becoming opened, deenergizes relay SS, which, in turn, through its contact 23, deenergizes indication device E. With relay SS deenergized, lock control magnet L will become energized by a circuit passing from terminal B, through contact 6 of relay SS, and the winding of lock control magnet L to terminal N.

With contact 25 of armature bu now closed, winding P of relay WR will be energized by current of reverse polarity passing from terminal B, through contact 24 of lever WV, line conductor 17a, contact 25 of armature bu, winding P, contact 15 of relay LR, line conductor 14a, and contact 26 of lever WV to terminal N. On account of winding P being energized by current of reverse polarity, armature p, controlled by winding P, will move its contacts 16, 17, 19 and 22 to the reverse position, thereby opening, at contacts 16 and 17, the circuit previously traced for winding BU in the direction indicated by the arrow, and also opening, at contact 19, the circuit previously traced for normal control magnet A.

When contacts 16 and 17 become closed in the reverse position, current will flow, in the direction opposite to that indicated by the arrow, through winding BU, by a circuit passing from terminal B, through contact 24 of lever WV, line conductor 17a, contact 17 of armature 7 closed in the reverse position, winding BU, contact 16 of armature p closed in the reverse position, contact 15 of relay LR, line conductor 14a, and contact 26 of lever WV to terminal N. With winding BU thus energized by current of polarity opposite to that indicated by the arrow, armature bu will move to the deenergized position, thereby opening its contact 25 in the circuit for winding P, and causing winding P to become deenergized.

With contact 19 of armature 12 now closed in the reverse position, reverse control magnet R will be energized by a circuit passing from terminal B, through contact 19 of armature p closed in the reverse position, and the winding of reverse control magnet R to terminal N. With contact 22 of armature p in its reverse position, while contact 21 of switch W is in the normal position, relay SS will be deenergized'although contact 20 of armature bu is now again closed. Lock control magnet L will therefore remain energized by the circuit previously traced through contact 6 of relay SS.

With lock control magnet L and reverse control magnet R of mechanism M both energized, switch W will now be moved to the reverse position. While switch W is moving between the normal and reverse positions, a second energizing circuit for lock control magnet L will also be closed, passing from terminal B, through contact 5 of switch circuit controller WC, and the winding of lock control magnet L to terminal N.

When switch W reaches the reverse position, the circuit for energizing the winding of lock control magnet L through contact 5 of switch circuit controller WC will again be opened. Also, when switch W reaches the reverse position, contact 21 of switch circuit controller WC will be closed in a second circuit for energizing relay SS, this circuit passing from terminal B, through contact 20 of armature bu, contact 21 of switch circuit controller WC in the reverse position, contact 22 of armature p in the reverse position, and the winding of relay SS to terminal N.

Relay SS, upon becoming energized, will open its contact 6, thereby deenergizing lock control magnet L. With relay SS again energized, indication lamp B will again be energized by its circuit previously traced.

I shall now again assume that all parts of the apparatus are returned to the normal condition and that the leverman again controls signal S to display a proceed indication for directing a train to move past signal S over switch W in the normal position. I shall assume also that, when the train passes signal S, and while it is on section a-b, switch W becomes misplaced.

Lock control magnet L will therefore again be energized by its circuit previously traced through contact 5 of switch circuit controller WC. With normal control magnet A energized by its circuit previously traced through contact 19 of armature p closed in the normal osition, and with lock control magnet L energized by the circuit through contact 5 of switch circuit controller WC, mechanism M will return switch W to the normal position.

I shall next assume that, with the arrangement shown in Fig. 2, a signal maintainer or other employee lifts latch h, preparatory to removing relay WR from the mounting plate x. Contact plate 27 therefore opens contact 27a27b, causing windings U and BU of relay WR to become deenergized. Contact plate 27 also rotates dog 9, around pivot d, out of engagement with armature u.

With dog 9 out of engagement with armature u, and with winding U of relay WR deenergized, armature u will be released to the deenergized position. Contacts 29, 30 and 31, operated by armature u, will therefore be opened.

I shall assume further that the maintainer later returns relay WR or replaces it by a similar relay. Preparatory to mounting the original relay WR or a new relay WR on the plate x, the maintainer will lift latch h, and will thereby raise contact plate 27, which will in turn move dog 9 out of engagement with armature u and will open contact 27a-27b in the control circuits for relay WR, thus insuring that armature u will drop to the deenergized position if it had been locked up before the original or new relay WR was returned to plate x.

If contacts 16, 17, 19 and 22 of the original or new relay WR are in the normal position, as shown, when this relay WR is mounted on the plate x, then when the maintainer releases the latch h, permitting contact 27a27b to again be closed, current will again pass through winding BU in the direction opposite to that indicated by the arrow, and therefore armature bu of winding BU will remain in the deenergized position. Contact 25 of armature bu will therefore remain open, and winding P will still be deenergized. With current now flowing through winding U in series with windning BU, armature u will be raised to its energized position, and will be locked there by dog 9. With armature u again in the energized position, its contact 29 will complete the circuit previously traced for normal control magnet A. The circuit for energizing relay SS will again be completed by contact 35 of relay U. Before relay SS opens its contact 6, lock control magnet L will be energized for a brief period of time by a circuit passing from terminal B, through contact 6 of relay SS, contact 31 of armature u, and the winding of lock control magnet L to terminal N. Relay SS, upon becoming energized, will open its contact 6, and will then again complete the circuit for lamp E through contact 23 of relay SS.

I shall now assume that all parts-of the apparatus are again in the normal condition, and that a maintainer again removes relay WR and later returns it, or replaces it by a similar relay, but that relay LR is deenergized because of a train on section ab, and that polar contacts 16, 17, 19 and 22 of relay WR are now in the reverse position, out of correspondence with the contacts of lever WV. When the leverman releases latch h for again locking relay WR onto mounting plate x, contact 27a27b will again become closed in the circuit previously described for windings U and EU of relay WR. With relay LR deenergized, however, its contact 15 will be open, and therefore relay WR will not become energized, and armature u will remain in the deenergized position. With armature u in the deenergized position, its contact 31 will be open, and therefore lock control magnet L will remain deenergized. Switch W, therefore, cannot be falsely moved to the reverse position on account of contact 19 being in the reverse position out of correspondence with the contacts of lever WV which is in its n position.

When relay LR again becomes energized, windings U and BU will be energized in series with each other by current flowing in the direction indicated by the arrow in the symbol for winding BU, in a circuit passing from terminal B, through contact 14 of lever WV, conductor 14a, contact 15 of relay LR, contact 16 of arma ture p closed in the reverse position, Winding BU, winding U, contact 17 of armature p closed in the reverse posion, contact 27a27b of latch h, conductor 17a, and contact 18 of lever WV to terminal N. The contacts operated by armature u will now become closed, but contact 28 of armature bu will be opened, and therefore reverse control magnet R will not become energized. With armature bu in the energized position on account of the energization of winding BU by current passing in the direction indicated by the arrow, winding P will be energized by current of normal polarity passing from terminal B, through contact 14 of lever WV, conductor 14a, contact 15 of relay LR, winding P, contact 25 of armature bu, contact 27a27b, line controlzconductor 17a, and contact 18 of lever WV to terminal N. Con tacts 16, 17, 19 and 22 of armature 12 will therefore be returned to the normal position. Current will then flow through winding BU in the direction opposite to the direction indicated by the arrow, and therefore armature bu will drop to the deenergized position, opening its contact 25 and closing its contact 28. Normal control magnet A will therefore again become energized by its circuit previously traced.

It follows that, with the arrangement shown in Fig. 2, if relay WR is removed from a given location, such for example as on mounting plate x, in which it is connected into the control circuit arrangement for switch W, and if relay WR is later returned, or is replaced by a similar relay, protection is provided against false operation of switch W if the polar contacts of armature p are out of correspondence with the contacts of lever WV when original relay WR or a new relay is again mounted on plate x.

Although I have herein shown and described only two 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:

1. In combination, a railway track switch, a polarized switch control relay mounted in a given location and embodying a polar armature and a first neutral armature and also a second neutral armature, means controlled by said first neutral armature in a deenergized condition for mechanically locking said polar armature in a normal or a reverse position, biased control means for said first neutral armature for placing said first neutral armature in an energized condition when said biased control means is energized by current of a given reverse polarity and for placing said first neutral armature in a deenergized condition when said biased control means is energized by current of the opposite polarity or is deenergized, pole-changing means manually operable to a normal or a reverse position, means controlled by said pole-changing means in its normal and reverse posi tions for eifecting operation of said polar armature to its normal and reverse positions respectively only if said first neutral armature is in its energized condition, neutral control means for said second neutral armature, means controlled by said pole-changing means and by said polar armature when in corresponding positions for energizing said biased control means and said neutral control means by current of said opposite polarity and when in non-corresponding positions for energizing said biased control means and said neutral control means by current of said given polarity, retaining means for keeping said second neutral armature in an energized position after said switch control relay becomes deenergized in said given location, means rendering said retaining means ineffective to keep .said second neutral armature in the energized position if said switch control relay is removed from said given location, and means controlled by said second neutral aramature in the energized position and by said polar armature in its normal and reverse positions for effecting operation of said switch to normal and reverse positions respectively.

2. In combination, a railway track switch, a polarized switch control relay mounted in a given location and embodying a polar armature and a first neutral armature and also a second neutral armature, means controlled by said first neutral armature in a deenergized condition for mechanically locking said polar armature in a normal or a reverse position, a first and a second control Winding for said first and second neutral armatures respectively, pole-changing means manually operable to a normal or a reverse position, means controlled by said pole-changing means in either its normal or its reverse position for energizing said second neutral control winding for operating said second neutral armature to an energized position, means controlled by said pole-changing means in its normal and reverse positions for effecting operation of said polar armature to its normal and reverse positions respectively only if said first neutral armature is in an energized position, means controlled by said pole-changing means and by said polar armature in only non-corresponding positions for energizing said first control Winding for operating said first neutral armature to its energized position, retaining means for keeping said second neutral armature in its energized position while said switch control relay is deenergized in said given location, means rendering said retaining means ineffective to keep said second neutral armature in the energized position if said switch control relay is removed from said given location, and means controlled by said second neutral armature in the energized position and by said polar armature in its normal and reverse positions for effecting operation of said switch to normal and reverse positions respectively.

3. In combination, a railway track switch, a polarized switch control relay mounted in a given location and embodying a polar armature and a neutral armature, pole-changing means operable to a normal and a reverse position, traific responsive means normally energized but becoming deenergized in response to a train adjacent said switch on a route in which said switch is included, means controlled by said pole-changing means in its normal and reverse positions for operating said polar armature to its normal and reverse positions respectively and operating said neutral armature to an energized position only if said traffic responsive means is energized, retaining means for keeping said neutral armature in its energized position after said switch control relay becomes deenergized, means rendering said retaining means ineffective to keep said neutral armature in the energized position if said switch control relay is removed from said given location, and means controlled by said neutral armature in the energized position and by said polar armature in its normal and reverse positionsfor eifecting operation of said switch to normal and reverse positions respectively.

4..In combination, an electrically controllable device operable to a first or a second condition, a polarized control relay mounted in a given location and embodying a polar armature and a neutral armature, pole-changing means operable to a normal and a reverse position, means controlled by said pole-changing means in its normal and reverse positions for operating said polar armature to its normal and reverse positions respectively and operating said neutral armature to an energized position, retaining means for keeping said neutral armature in its energized position after said polarized control relay becomes deenergized, means rendering said retaining means inefiective to keep said neutral armature in the energized position if said polarized control relay is removed from said given location, and means controlled by said neutral armature in the energized position and by said polar armature in its normal and reverse positions for effecting operation of said electrically controllable device to said first or second condition respectively.

5. In combination, a railway track switch, a polarized switch control relay mounted in a given location and embodying a polar armature and a neutral armature, polechanging means operable to a normal and a reverse position, tratfic responsive means normally energized but becoming deenergized in response to a train adjacent said switch on a route in which said switch is included, means controlled by said pole-changing means in its normal and reverse positions for operating said polar armature to its normal and reverse positions respectively and operating said neutral armature to an energized position only if said traflic responsive means is energized, retaining means for keeping said neutral armature in its energized position after said switch control relay becomes deenergized, means for deenergizing said switch control relay and rendering said retaining means ineffective to keep said neutral armature in the energized position when said switch control relay is removed from or returned to said given location, and means controlled by said neutral armature in the energized position and by said polar armature in its normal and reverse positions for effecting operation of said switch to normal and reverse positions respectively.

References Cited in the file of this patent UNITED STATES PATENTS 1,806,817 OHagan May 26, 1931 2,060,485 Bell Nov. 10, 1936 2,082,179 OI-Iagan June 1, 1937 2,195,884 Dalzell Apr. 2, 1940 2,491,098 Field Dec. 13, 1949

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