US2829851A - Switch control and indication circuits - Google Patents

Description

April 8, 1958 J. R. GEORGE 2'1 m. 2,829,851

SWITCH CQNTROL AND INDICATION CIRCUITS Filed June 18, 1956 1 w. 5 91mm. 6 W i flu RE W b m a .5 n E u D n m 6 0 I." m q. W 0 a b, c d. F vm u 14 B m r L P 4 W q A a H 4 m B A -m w Indication r Uzrcuzis INVENTORS. John 12. George and Sill Hsuin Zsz'ang THEIR ATTORNEY SWITCH CGNTROL AND INDICATION CIRCUITS John R. George, Concord, Mass., and Sih HsuinTsiang, Morristown, N. J., assignors to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsyb Vania Application June 18, 1956, Serial No. 592,052

Claims. (Cl. 246-258) Our invention relates to switch control and indication circuits in railway trafiic control systems, and particun ite States Patent larly to novel and improved circuits for indicating the I positions of a railway track switch.

In some previous switch position indication circuits it has been necessary to employ rectifiers to prevent improper operation of the normal and reverse switch indication relays. These rectifiers have certain inherent disadvantages.

One object of our present invention is to provide simplified switch indication relay circuits which are reliable in operation, and which do not require the use of rectifiers.

Another object of our invention is to provide switch indication relay circuits of the type described which insure against improper relay energization.

Another object of our invention is to provide switch position indication circuits capable of reliable operation with a fewer number of parts. 7

Other objects and characteristic features of our invention will be come apparent as the description proceeds.

In practicing our invention we provide normal and reverse switch position repeater relays for a track switch which are controlled over a switch point circuit controller to indicate whether the track switch is in its normal or reverse position or traveling between the two extreme positions. A switch repeater relay provided for returning the track switch to its original position, should it become stalledin an attempted move, is provided and controlled over the circuit controller contacts used to control the normal and reverse position repeater relays. With this arrangement the track switch control is obtained with the circuit controller contacts maintained to a minimum and at the same time obtaining r safe accurate switch indication relay operation without the necessity of providing rectifier units for preventing incorrect indication circuits.

In the accompanying drawings, Fig. 1 shows one form of switch control and indication circuits embodying our invention.

Fig. 2 is a viewshowing a modified form of switch control and indication circuits embodying our invention.

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

Referring to the embodiment of our invention shown in Fig. l, the reference character SW designates a track switch located within a detector section set off by insulated joints 1 in rails 2 and 3. The insulated section of the track is provided in the usual manner with a track battery 4- and a track relay TR. The track switch SW is controlled by a switch machine SM preferably of the electropneumatic type, the switch machine SM being controlled over a pair of line wires from a remote location by a typical switch lever L to selectively move the switch between its normal and reverse positions. The switch mechanism SM comprises a normal valve magnet NW and a reverse valve magnet RW, it being understood that ice the switch mechanism SM causes its associated switch SW to operate to its normal position when the normal valve magnet NW is energized and to a reverse position when the reverse valve magnet RW is energized. The switch mechanism also has associated therewith a polechanging circuit controller designated as SC and provided with three circuit controlling segments D, E and F having movable contact arms 5, 6 and 7, respectively. The circuit controller contact arms 5, 6 and 7 are arranged to be closed in their left-hand position, as shown in the drawing, when the track switch is in its normal position. Upon movement of the track switch from its normal to its reverse position, the contact arm 6 of the circuit controller segment E becomes open almost immediately and then closed to its'right-hand side. The contact arm 5 of the circuit controller segment D be comes open as the track switch is at its mid point and closed to the right side just following movement past the mid point. The contact arm 7 of circuit controller segment F remains closed in the left-hand position until the track switch has nearly completed its movement to its reverse position, at which time the controller becomes open and closed in its right-hand position. The reasons for the different sections opening and closing at different times will become apparent as the description proceeds.

The lever L controlling the operation of the switch mechanism SM is adapted to assume two positions as illustrated in the drawing, comprising a normal position N and a reverse position R. The lever L is provided with a movable armature 8 which may engage its normal contact as shown by the heavy line in the drawing or its reverse contact as shown by the dotted line position. This lever is used to control the magnets NW and RW for selectively controlling the switch mechanism SM for moving track switch rails between the normal and reverse positions, as will hereinafter appear.

Operatively associated with the track switch SW and the track relay TR are a switch repeater relay WPR, a reverse and a normal switch position repeater relay RWRP and NWRP, respectively, and the circuit controller SC. For reasons hereinafter appearing, the switch position repeater relays RWRP and NWRP are each provided with two similar coils, hereinafter referred to as the upper or lower coils, the arrows'on the coils showing the winding sense of each coil. The WPR relay is a slow release relay as indicated. The track relay TR is provided with two front contacts a and b and two back contacts 0 and d, while the switch repeater relay WPR is provided with back and front contacts a, b and c. The front and back contacts 0 of relay WPR are make-before-break contacts and are indicated by a small arc crossing the free end of the contact arm. The switch position repeater relays are each provided with a back contact a and a front contact b.

The track switch SW as illustrated in Fig. 1 is in its normal position with the lever L in its normal position. Under these circumstances, the normal valve NW has an energizing circuit completed except for its interruption by the circuit controller segment E of the circuit controller SC. This circuit can be traced from terminal B of a suitable source of power over the manually movable contact 8' of the manual lever L closed in its N position over front contact 12 of a switch repeater relay WPR, front contact b of the track relay TR, the normal magnet NW, and to the left-hand side of the circuit controller segment E. It can be seen that the normal magnet is deenergized at this time. However, if the track switch should'be displaced for some reason, the circuit controller segment E would become closed to its right-hand side by the contact arm 6 completing the normal magnet NW circuit to the battery terminal C. This would cause Patented Apr. 8, 1958' the switch machine SM to become operative to return the track switch points to their normal position, at which time the circuit for the magnet NW would again be interrupted by the segment E of the circuit controller SC.

The normal switch position repeater relay NWPR is energized as long as the track switch SW is in its normal position and becomes deenergized when the track switch is moving or is in its reverse position. The reverse switch position repeater relay RWPR is energized when the track switch SW is in its reverse position and becomes deenergized when the.track switch is moving or is in its normal position. With the track switch in its normal position as shown in the drawing, the circuit controller SC completes a pickup circuit for the normal switch position repeater relay NWPR, the circuit being traceable from terminal battery B through a current limiting resistor 9, the upper winding of the normal switch position repeater relay NWPR, the left-hand end of the circuit controller segment E and then through the contact arm 6 of the circuit controller to the terminal C of the source of power. An additional energizing circuit for the relay NWPR may be traced over the front contact c of switch repeater relay WPR from terminal'B of the power supply, through the winding of the switch repeater relay WPR, back contact a of the reverse switch position repeater relay RWPR, the lower winding of the relay NWPR, and through the circuit controller segment E to the source terminal C. Current passing through the two windings of the relay NWPR is in such a direction that the flux set up in each winding is additive to aid in picking up the contacts of this relay.

Reverse switch position repeater relay RWPR at this time is deenergized since its circuit is interrupted at circuit controller segment F of the circuit controller SC, the contact arm 7 being in its left-hand or normal position. It is apparent, therefore, that when the track switch SW is in its normal position and the control lever L is also in its normal position and no train is in the track section, the relays TR, NWPR and WPR are energized. V

Operation of the track switch SW will now be considered under the conditions of moving the manual lever L from its normal position to its reverse position, no train being in the track section. When the operator moves the lever L to its reverse position, the contact 8 is moved to its reverse position to complete the circuit for the switch mechanism operating magnet RW. This circuit may be traced from source terminal B over contact 8 in its reverse position, front contact a of the relay WPR, front contact a of the track relay TR, the winding of the operating magnet RW through contact 7 of the F segment of the circuit controller SC to the power terminal C. Initiation of the movement of the track switch SW from its normal position toward the reverse position causes the arm 6 of the circuit controller C to interrupt the energizing circuits for both the upper and lower windings of tthe normal switch position repeater relay NWPR, causing this relay to become deencrgizcd and to open'its previously completed remote I indication circuits over its front contact b. Although at this time the energizing circuit for the switch repeater relay WPR is interrupted, this relay being of the slow release type maintains its contacts in their normal energized position. switch SW from its normal to reverse position causes the circuit controller contact arm 7 to interrupt the reverse control magnet RW circuit and complete the energizing circuit for the reverse switch position repeater relay RWPR. The energizing circuit for the relay RWPR may be traced from terminal B of the source of power through a current limiting resistor 10, the upper winding of the reverse switch repeater relay RWPR, and through the circuit controller segment F and the contact arm '7 closed in its right-hand position to the power ter- Continued movement of the track minal C. At the same time an additional energizing path is completed for the relay RWPR from source terminal B through series resistor 9, the upper winding of the relay NWPR, the lower winding of the relay NWPR, back contact a of the relay RWPR, back contact a of the relay NWPR, the lower winding of the relay RWPR, and through the contact arm 7 of the circuit controller segment F to the source terminal C. This causes the relay RWPR to become energized and pick up its contacts. The relay NWPR will remain deenergized due to the act that the current through the upper and lower windings of the relay are in opposite directions resulting in opposing fluxes. In relay RWPR the current flow through the upper and lower windings is in the same direction, causing adding fluxes to energize the relay.

Operation of the track switch SW of Fig. 1 will now be discussed under conditions where the operator selects movement from normal to reverse and the switch points encounter an obstacle which prevents full movement to the reverse position. Upon movement of the switch control lever L from its N to its R position, the switch mechanism control magnet RW is energized over the circuit hereinbefore described. Movement of the contact arms 5, 6 and 7 of the circuit controller SC, as previously described, causes the normal and reverse switch position repeater relays to become deenergized and at the same time interrupts the energizing circuit for the switch repeater relay WPR at contact arm 6 of the segment E of the circuit controller SC. Movement of the switch points of the track switch SW continues until it strikes the obstacle, preventing the track switch from completing its movement to the reverse position and preventing the circuit controller SC from completing its movement to is full right-hand position. After a specified period of time, the slow release, switch repeater relay WPR drops its contacts, causing the previously recited circuit for the control magnet RW to be interrupted and a new circuit to be completed for the control magnet NW for the switch mechanism SM. The circuit for control magnet NW may be traced from the source terminal B over the contact arm 8 of the control lever L in its reverse position, over the closed back contact a of the switch repeater relay WPR, the front contact b of the track relay TR, the normal control magnet NW, and through the contact arm 6 of the circuit controller segment E which is closed in its righthand position upon a very small amount of movement of the switch points from their normal toward their reverse position. 'This circuit now being completed causes the normal control magnet NW to be energized and the switch mechanism to move the track switch SW back to its normal position. The relay NWPR is now energized to give an indication at the remote location that the switch SW has been returned to its normal position. The switch repeater relay WPR remains deenergized, the energizing circuit for the relay being open at the front contact of the make-before-break contact c of the relay. Return movement of the switch control level L to its normal position at this time will prevent a repeat of the previous switch operation until the obstacle can be removed from the path of the switch points of the switch SW.

Should the track switch SW vbe in its reverse position and the control lever L is moved from its reverse position to its normal position to return the track switch to its normal position, and during such movement of the track switch an obstacle is met, preventing the return of the switch, the switch repeater relay WPR will become deenergized due to the opening of the energizing circuit at the circuit controller contact arm 7 of segment F. Deenergization of relay WPR will permit energization of switch mechanism reverse magnet RW to return the switch to its reverse position, the energizing circuit for magnet RW being now traceable over the back contact b of relay WPR and front contact 4. of the track relay TR. The reverse switch position repeater relay RWPR will then become energized over contact arm 7 of segment F of the circuit controller to indicate the reverse position of the track switch at the remotecontrol point.

It will be noted that in both instances wherein the switch points meet an obstacle in their movement, the relay WPR remains deenergized even when the lever L is moved into its position of coincidence. The deenergized condition of the relay WPR is maintained to prevent the cycling action of the switch mechanism in attempting to move the switch SW into coincident position with the lever L which would otherwise occur should the relay WPR have become energized under the obstruction conditions. Relay WPR will be energized again upon shunting of the track relay TR, the back contact d of the track relay closing under these circumstances to supply energy from the B terminal over the make-before-break back contact c of the relay to the relay coil. Thus the track switch SW will remain in either its normal or reverse position until the obstruction to the movement of the switch is removed and the track relay TR shunted.

Assume that the operator places the selector lever L in its reverse position for movement of the track switch SW to its reverse position and that immediately following this operation a train or vehicle enters the track switch detector section. The track relay TR becomes deenergized to open the previously traced energizing circuit for the reverse control magnet RW of the switch mechanism SM at the front contact a of the track relay TR. The front contact b of the track relay TR also opens to interrupt the previously traced energizing circuit for the normal control magnet NW of the switch mechanism. The operation of lever L is thus inefiective to control the switch mechanism SM. The back contact c of the track relay TR closes to connect the source terminal B to the contact arm of the circuit controller SC. If the track switch SW has started its movement but has not reached the midway or the mid stroke position, the contact arm 5 connects the source terminal B to the normal control magnet NW to cause the track switch to return to its normal position. This circuit may be traced from source terminal B over back contact c of the track relay TR, the contact arm 5 over the left-hand portion of segment D of the circuit controller SC to the winding of the normal magnet NW, thence through the right-hand portion of segment E of the circuit controller SC to the source terminal C.

If, however, the switch has traveled more than half way or past the mid stroke position under the stated conditions, the contact arm 5 would then be closed in its right-hand position, completing the energizing circuit to the control magnet RW of the switch mechanism to operate the switch points to their reverse position. This circuit may be traced from source terminal B over the back contact c of the track relay TR, the contact arm 5 of the circuit controller segment D closed in its right-hand position, the winding of the control magnet RW of the switch mechanism over the contact arm 7 of the circuit controller segment F to the source terminal C.

Should the track switch SW be in its reverse position and the lever L moved to its normal position and immediately thereafter a train enter the detector section, the operation of the circuit described will be similar, the switch mechanism SM returning the track switch to its reverse position. Should there be a time lag be tween the operation of the lever L and entry of a train into the detector section, the time lag being suffieient for the circuit controller contact arms to pass over the mid stroke position, the switch mechanism SM will continue the movement of the switch points to their normal position in a manner similar to that described, the con- 6 trol of the switch mechanism magnet NW being over the back contact 0 of the track relay TR.

In the event a train is in the detector section and the lever L is moved either from its normal position to its reverse position, or vice versa, the shunting of the track relay TR will open its front contacts a and b to open the energizing circuits for the switch mechanism magnets RW and NW, thus preventing any operation of the switch mechanism SM.

The modification shown in Fig. 2 operates in a manner similar to that described in connection with Fig. l with exception that the normal and reverse switch position repeater relays RWPR and NWPR are single winding relays which are energized over parallel circuits. In the modification illustrated in Fig. 2, the relay WPR is provided with front and back contacts a and b, a front contact 0 and a back contact a. The track relay TR is provided with front contacts a and I], back and front contacts 0 and a back contact d, while the switch position repeater relays RWPR and NWPR are each provided with a front contact a for controlling the indi cating circuits.

The normal and reverse swtich position repeater relay circuits differ slightly from the circuits of Fig. l and from the drawing, it being evident that the relay NWPR is energized over a circuit leading from terminal B through the series dropping resistor 9, the winding of the relay NWPR throughthe contact arm 6 of the circuit controller segment E closed in its left-hand position to the source terminal C. An additional parallel path may be traced from terminal B over the front contact c of the switch repeater relay WPR, the winding. of the switch repeater relay WPR, the'winding of the normal repeater relay NWPR, and the contact arm 6 of the circuit controller segment E to terminal C. As in the embodiment illustrated in Fig. 1, the coils of the relays WPR and NWPR (or RWPR) are connected in series in the same energizingcircuit when the relay WPR is energized.

Movement of the switch control lever L from its normal to its reverse position and movement of the track switch SW to its reverse position, as hereinbefore described, cause the circuit controller segment E contact arm 6 to interrupt the energizing circuit for its repeater relay NWPR and the circuit controller segment F contact arm 7 to complete an energizing circuit for the reverse repeater relay RWPR. This energizing circuit may be traced from terminal B through series dropping resistor 9, winding of the relay RWPR, the contact arm 7 of the circuit controller segment F closed in its righthand position to the source terminal C. A second energizing circuit is also completed and may be traced from source terminal B over front contact 0 of the switch repeater relay WPR, the winding of relay WPR, the winding of the reverse repeater relay RWPR, and the circuit controller segment F contact arm 7 closed in its right-hand position, to the source terminal C.

Under conditions wherein the switch control lever L is moved to its reverse or normal position to move the switch points, and switch movement to the selected position is not completed due to an obstruction blocking the switch points, another parallel energizing circuit for the switch position repeater relays is established to as sure sufficient pickup energy for these relays. As previously described in connection with the operation of the switch indicating circuits shown in Fig. 1, the slow release switch repeater relay WPR becomes deenergized after a certain established time period when the switch points encounter an obstacle preventing full travel of the switch points. The deenergization of relay WPR completes the additional energizing circuit for the normal and reverse switch position repeater relays from source terminal B over front contact c of the track relay TR, back contact 03 of the relay WPR, through a resistance 11 and to the windings of each of the reiays NWPR and RWPR, the proper relay being selected by the contact segments of the circuit controller SC. It will be appreciated that the coil of relay WPR and the resistance 9 are connected in parallel, the relay coil and resistance being connected in series with the coil of relay NWPR or RWPR. The deenergization of the WPR relay'will cause a reduction in the current flowing through the switch position repeater relays which may prevent these relays from picking up when the contact arms 6 and 7 of the circuit controller are moved to engage the right or left-hand segments of the controller. ergization of the relay WPR completes a circuit whereby the resistance 11 is connected in parallel with the resistance 9 to provide the necessary current to insure energization of these relays.

In order to reenergize the switch repeater relay WPR it is again necessary to shunt the track relay TR to close its back contact c to the source of power to complete the energizing circuit for the relay WPR. In the modification shown in Fig. 2, the pickup circuit for the relay WPR is controlled over the back contact '0 of the track relay TR which is connected directly to the winding of the relay WPR without going through a make-before-break back contact of the repeater relay WPR as in the first embodiment of our invention. The control and indication circuits illustrated in Fig. 2 operate in a manner similar to that described in connection with the circuits of Fig. 1 when a train is about to enter or is in the switch section when the control lever L is moved from one position to another position preparatory to moving the track switch SW.

The switch control and indication circuits of our invention have the advantage of providing reliable switch operation and positive switch position indications, the reliable and positive results being accomplished with a minimum number of circuit elements.

Although we have herein shown and described only two forms of switch circuit control and indication embodying our invention, it is to be 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 our invention.

Having thus described our invention, what we claim the 1. In combination, a railway track switch movable b'etween a normal and a reverse position, a switch mechanism for effecting movement of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy to energize the normal and the reverse switch position repeater relays when said circuit controller contact arms are in coincident normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of said control lever into its extreme positions to move said switch to a position coincident with said control lever, said last means including said circuit controller arms; a slow release relay connected in parallel with said resistance and in series with said switch position repeater relays to said circuit controller arms to the source of energy to energize said slow release relay, and means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said switch makes an incomplete movement toward its normal or reverse position.

2. In combination, a railway track switch in a detection section and movable between a normal and a reverse position, a switch mechanism for etfecting movement ofthe switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, normal and reverse magnets for said switchlmechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy to energize the normal and the reverse switch position repeater relays when said circuit controllercontact arms are in coincident normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of said control lever to its extreme positions to move said switch to a position coincident with said control lever, said last means including said circuit controller arms; a track circuit including a track relay for said section, a slow release relay normally energized over its own front contact and connected in parallel with said resistance and in series with said switch position repeater relays to said circuit controller arms, deenergization of said track relay opening the energizing circuits for said magnets, said contact arms of said circuit controller controlling the energization of said magnets depending upon the position of said switch at the time the track relay becomes deenergized to operate said switch to its normal or reverse position upon movement of said control lever, and means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said switch makes an incomplete movement toward its normal or reverse position.

3. In combination, a railway track switch movable between a normal and a reverse position, a switch mechanism for effecting movement of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, said switch position repeater relays having two windings; normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy connectable to one'winding of the normal and the reverse switch position repeater relays when said circuit controller contact arms are in their respective normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of said control lever to its extreme positions to move said switch to a position coincident with said control lever, said last means including said circuit controller arms; a slow release relay connected in parallel with said resistance and in series with the second winding of a switch position repeater relay to said circuit controller arms when said circuit controller arms are in an extreme position coincident with the lever position to energize the respective position repeater relay and said slow release relay, and means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said switch makes an incomplete movement toward its normal or reverse position.

4. In combination, a railway track switch movable between a normal and a reverse position, a switch mechanism for effecting movement of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, said switch position repeater relays having two windings; normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position,

a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy connectable to one winding of the normal and the reverse switch position repeater relays when said circuit controller contact arms are in their respective normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of the control lever to its extreme position to move said switch to a position coincident with said control lever, said last means including said circuit controller arms; a slow release relay connected over its own front contact in parallel with said resistance and in series with the second windings of said switch position repeater relays and said circuit controller arms to said source to energize one of said repeater relays and said slow release relay, and means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said switch makes an incomplete movement toward its normal or reverse position.

5. In combination, a railway track switch movable between a normal and a reverse position, a switch mechanism for etfecting movement 'of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, said switch position repeater relays having two windings; normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy connectable to one winding of the normal and the reverse switch position repeater relays when said circuit controller contact arms are in their respective normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of the control lever to its extreme positions to move said switch to a position coincident with said control lever, said last means including said circuit controller arms, a slow release relay connected over its own front contact in parallel with said resistance and in series with the second windings of said switch position repeater relays and said circuit controller arms to said source to energize one of said repeater relays and said slow release relay, said slow release relay being connected to said source over front contacts of said repeater relay, and means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets 'over a contact arm of the circuit controller when said switch makes an incomplete movement toward its normal or reverse position.

6. In combination, a railway track switch in a detection section and movable between a normal and a reverse position, a track circuit including a track relay for said section, a switch mechanism for effecting movement of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, said repeater relays having two windings, normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy to energize the normal and the reverse switch position repeater relays when said circuit controller contact arms are in coincident normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of said lever to its extreme positions to move said switch to a pos1tion coincident with said lever, said last means including said circuit controller arms; a slow release relay normally connected over front contacts of said slow release and track 10 relays and connected in parallel with said resistance and in series with the second windings of said switch position repeater relays and said circuit controller arms to said source to energize one of said repeater relays and said slow release relay, deenergization of said track relay opening the energizing circuits for said magnets, said contact arms of said circuit controller controlling the energization of said magnets depending upon the position of said switch at the time the track relay becomes deenergized to operate said switch to its normal or reverse position upon movement of said control lever, and means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said switch makes an incomplete movement toward its normal or reverse position.

7. In combination, a railway track switch in a detection section and movable between a normal and a reverse position, a track circuit including a track relay for said section, a switch mechanism for effecting movement of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, said repeater relays having two windings, normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy to energize the normal and the reverse switch position repeater relays when said circuit controller contact arms are in coincident normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of said lever to its extreme positions to move said switch to a position coincident with said lever, said last means including said circuit controller arms; a slow release relay normally connected over front contacts of said slow release and track relays and connected in parallel with said resistance and in series with the second windings of said switch position repeater relays over front contacts of said repeater relays and said circuit controller arms to said source to energize one of said repeater relays and said slow release relay, deenergization of said track relay opening the energizing circuits for said magnets, said contact arms of said circuit controller controlling the energization of said magnets depending upon the position of said switch at the time the track relay becomes deenergized to operate said switch to its normal or reverse position upon movement of said control lever, and means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said switch makes an incomplete movement toward its normal or reverse position.

8. In combination, a railway track switch in a detection section and movable between a normal and a reverse position, a track circuit for said section including a track relay, a switch mechanism for effecting movement of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, said repeater relays having two windings, normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and source of energy connectable to one of the windings of the normal and the reverse switch position repeater relays when said circuit controller contact arms are in coincident normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of said lever to its extreme position to move said switch to the position coincident with said lever, said last means including said circuit controller arms; a slow release relay normally connected over front contacts of said slow release and track relays and -connected in parallel with said resistance and in series over the 'front contacts of the repeater relays with the second windings of the repeater relays and said circuit controller arms to the source of energy to energize one of the repeater relays and the slow release relay,"deenergization of said track relay opening the energizing circuits'for said magnets, said contact arms of said circuit controller controlling the energization of said magnets depending upon the position of said switch at the time the track relay becomes deenergized to operate said switch to its normal or reverse position upon movement of said control lever, and means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said switch makes an incomplete movement toward its normal and reverse positions, said slow release relay becoming deenergized when the time period to move said switch to an extreme position is longer than the release time of said relay, the deenergization of said slow release relay opening the selective energizing circuits of said magnets by said control lever.

9. In combination, a railway track switch movable between a normal and a reverse position, a switch mechanism for effecting movement of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy to energize the normal and the reverse switch position repeater relays when said circuit controller contact arms are in coincident normal and reverse positions, means for selectively ener gizing the normal and reverse magnets of said switch mechanism upon movement of said control lever to move said switch to a position coincident with said lever, said last means including said circuit controller arms; a slow release relay connected over its front contact in parallel with said resistance and in series with said switch position repeater relays and said circuit controller arms to the source of energy to energize said slow release relay and one of said repeater relays, means controlled over the back contacts of the slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said slow release relays become deenergized when said switch makes an incomplete movement toward its normal and reverse positions taking longer than the release time of the slow'release relay, a second resistance, and a back contact on said slow release relay to connect said second resistance in parallel with said first resistance in the energizing circuits of said repeater relays.

10. In'combination, a railway track switch in a detection section and movable between a normal and a reverse position, a track circuit for the section including a track relay, a switch mechanism for effecting movement of the switch between its two extreme positions, normal and reverse switch position repeater relays including means controlled thereby to indicate the extreme position of said switch, normal and reverse magnets for said switch mechanism, a control lever movable between a normal and a reverse position, a circuit controller having contact arms movable with said switch between a normal and a reverse position, circuit means including a resistance and a source of energy to energize the normal and the reverse switch position repeater relays when said circuit controller contact arms are in coincident normal and reverse positions, means for selectively energizing the normal and reverse magnets of said switch mechanism upon movement of said lever to its extreme positions to move said switch to a position coincident with said lever, said last means including said circuit controller arms; a slow release relay connected over the front contacts of said slow release and track relays and connected in parallel with said resistance and in series with said switch position repeater relays and said circuit controller arms to said source to energize one of said repeater relays and said slow release relay, deenergization of said track relay opening the energizing circuits for said magnet-s, said contact arms of said circuit controller controlling the energization of said magnets depending upon the position of said switch at the time the track relay becomes deenergized to operate said switch to its normal or reverse position upon movement of said control lever, means controlled by said slow release relay to pole change the selective energizing means of the normal and reverse magnets over a contact arm of the circuit controller when said slow release relay becomes deenergized when said switch makes an incomplete movement toward its normal and reverse positions taking longer than the release time of the slow release relay, a second resistance, and means controlled by said slow release relay to connect said second resistance in parallel with the first resistance upon deenergization of said slow release relay.

References Cited in the file of this patent UNITED STATES PATENTS

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