US2101204A - Railway traffic controlling apparatus - Google Patents

Description

Dec. '7, 1937.

H. C. VANTASSEL RAILWA Y TRAFFIC CONTROLLING APPARATUS 3 Sheets-Sheet 1 Filed April 14, 1936 INVENTOR [[aPPyC'. l illzzarrel,

ATTORNEY H. c. VANTASSEL 2,101,204 RAILWAY TRAFFIC CONTROLLING APPARATUS I Filed Aprtii 14, 1936 5 Sheets-Sheet 2 Dec. 7, 1937.

Dec. 7, 1937.

H, C. VANTASSEL RAILWAY TRAFFIC CONTROLLING APPARATUS 3 Sheets-Sheet 3 Filed April 14, 1936 INVENQTOR Harry C. KmZcmml waz zzza HIS ATTORNEY Patented Dec. 7, 1937 PATENT OFFICE ILWAY RAFF C C% 'IBQ LING APPARA Harry G. Vantass'el, Swissvale, Pa., assignor to The Union Switch & Signal'Oompany, SWISS- uale, Pa, a corporation of Pennsylvania hpli tti n Apr l 1 36, S ria o- 74 256 *9 Claims.

M i en o r l tes t ilwa aff c nt oline a p at and par ic arl to a parat s I r pr e in im ope Operation of a ura y f manua ly p ab e track s ches which are l lo ated n h ame ack se tion. I

I wil desc ibe th ee orm o annaatus embodyi g m invent on and w ll t en po t u he n el fea u es there cl im the accom anyin d win s, i is a (liar m eram at i w sh in on form o appara s embo y my inv ntion, Fi 2 is a dia am: mati vi w-sh win another orm O ap aratu em o ng my inv nt F 3 i a w simi ar to Fi 2 showing a o fication of h ppa a us.

15 illustrated in Fig.2.

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

Referring first to Fig. 1, the reference characters I and l designate the track rails of a 20 stretch A of railway track'o-ver which trafiic normally moves from left to right. The rails l and i are divided, by means of insulated joints 2, to form a plurality of track sections only one of which B--.C is shown complete in the drawings. 25 Each track section is provided with atrack circuit including a battery 3 connected across the rails adjacent one end of the section, and a track relay, designated by the reference character R with a distinguishing exponent, connected across the rails adjacent the other end ,of the section. Traflic entering each track section is governed by a signal S which may beof any suitable type, but which, in the formhere shown, is a twoposition semaphore signal capable of indicating 35 proceed or stop according as the signal is energized or vdeenergizecl. Located in section 3-0 are a plurality of manually operable track switches S S and S which connect this section with a plurality of spurs or 410 sidings D D and D respectively. Each siding is insulated from section B--.C by means of two sets of insulated joints 2, and the rails of each siding between the pairs of joints are cross-bond.- ed with the rails ,of section B-C in the usual and 45 well-known manner. The means for manually operating the switches S S and S may be of any suitable type, but inasmuch as these means form no part of my present invention, they are omitted from the drawings for the sake of sim- 50 plicity.

Associated with each switch S is a relay designated by the reference character E with a distinguishing exponent; a switch operated contact designated by the reference character F with ,a 5;; distinguishing exponent, and arranged to be sed or o en cco din s the as o ia SWitch c u it n rmal 9 er resi h a time release designated the reference character TR ith a di gui h n e p nen a push u o d signat d by the reie eh e chara te P with a st h n nent and t o indica d ies des gnat d b t e f renc c a te G and W, respectively, with suitable distinguishing x o ents V The time releases TR may be of any desired pe u ashe wn each t m e e s eckwcrk tim r leas simil r t t atsho a d descr bed in Lette a ent of he U ited ates Nole 522 gra t d t W- McWh 9h 7 29, .5, or o erned rcu cen-t oline me hanism.- .S h e the ti e l a e T a im lar t he m rele se shown i th a d Me -i Whirter atent. i is bel ved that or purp ses f. t e s n .di eles e i i hfl c to at t at ea h o th se i e re ases comprises w norm l c d c n acts. 4 and fi wh c bec m opened immediately when the time release is set into operation, and a normally open contact 6 w h c m s c o d a h exri atiph o a p determined time interval after the time release is set into operation. Afterv a time release has been operated to open its contacts 4 and 5 and to close its contact .6, the contacts 4 and 5 will subseq entlr rem i o en and th o ta 6 w l remain closed until the time release is manually 3o restoredto its normal condition. Each relay E is provided with a pickup circuit which is controlled by the associated push button P, by the other two relays E, and by the two track relays R and RF. The pickup circuit for relay E passes from terminal BX of a suitable source of current, not shown in the drawings, through front contact I of track relay R line wire 8, front contact 9 of track relay R wire 10, back contact Ij-y-Il of relay E wire l2, back contact I l--.-I In of relay Ehwire I4, push button P and the winding of relay E to the other terminal .CX of the source. The pickup circuit for relay E passes from terminal BX of the source through front contact I of track relay R wire 8, 5 front contact 9 of track relay BF, wire It], back contact Ill l of relay E wire l2, push button P the winding of relay E wires i5 and i6, and back contact ll of relay E to terminal ,CX of the source. The pickup circuit for relay E3 passes from terminaljBX of the source through front contact :1 of relay R wire 3, front contact 9 of track relay R wire l0, push button P wires 18 an 19, a ont ct f la 1 w 16. d back contac of. re ay E t termina 0X 5.

Each relay E is also provided with a stick circuit which is similar to its pickup circuit with the exception that the stick circuit includes the front contact Ill l of the relay in place of the associated push button P.

It will be seen, therefore, that if the push button P associated with one of the relays E is depressed, it will complete the pickup circuit for the associated relay E provided the other two relays E are both deenergized and section BC and the section to the left of section BC are both unoccupied. It will also be seen that when one of the relays E becomes energized, the resultant closing of its front contact lll l will complete the stick circuit for the relay, and the relay will, therefore, subsequently remain energized until a train enters section BC or the section to the left of this section and deenergizes the associated track relay. It will further be seen that since the pickup circuit for each of the relays E can only become closed when the two remaining relays E are deenergized, the energization of any one of the relays E will prevent the other two relays E from becoming energized until after such energized relay subsequently becomes deenergized.

The indication devices G and W, which indication devices are here shown as electric lamps, are each connected in multiple with the associated relay E over the contacts and 6, respectively, of the associated time release TR. It will be seen, therefore, that when either the pickup or stick circuit for one of the relays E is closed, the associated lamp G or W will be energized according as the contact 5 or the contact 6 of the associated clockwork time release is then closed.

The signal S is controlled by a signal control relay SC over a circuit which is obvious from an inspection of the drawings, and the signal control relay SC, in turn, is controlled by the relays E, by the switch operated contacts F, by the contact 4 of each of the time releases TR, and by track relay R over a circuit which passes from terminal BX of the source through front contact 20 of the associated track relay RC, switch operated contact F contact 4 of time release TR back contact 2! of relay E switch operated contact F contact 4 of time release TR back contact 2| of relay E switch operated contact F contact 4 of time release TR back contact 2| of relay E and the winding of relay SC to terminal CX of the source. It will be apparent, therefore, that signal S will indicate proceed or stop according as signal control relay SC is energized or deenergized, and that relay SC will be energized when and only when the relays E are all energized, the switches S all occupy their normal positions, the contact l of each of the time releases TB is closed, and section BC is unoccupied.

As shown in the drawings, all parts are in their normal positions. That is to say, section BC and the section to the left of this section are both unoccupied, so that track relays R and R are both energized, the switches S all occupy their normal positions, the switch operated contacts F are all closed, the relays E are all deenergized, the

.time releases TR all occupy their normal positions, the indication lamps G and W are all extinguished, signal control relay SC is energized, and signal S occupies its proceed position.

In explaining the operation of the apparatus as a whole, I will assume that siding D is occupied by a train, and that it is desired to move this train out of the siding into section BC. To do this, the trainman depresses push button P whereupon if relays E and E are both deenergized and section BC and the section to the left of this section are both unoccupied, relay E will immediately pick up and lamp G will become lighted. If, however, either relay E or relay E is energized, or if section BC or the section to the left of section BC is unoccupied, relay E will remain deenergized and lamp G will remain dark. Assuming that relay E does pick up and lamp G becomes lighted, the trainman is informed by the lighting of the lamp that section BC and the section to the left of this section is unoccupied and he will then operate time release TR The operation of this time release will immediately interrupt the circuit which was previously closed for lamp G whereupon this lamp will become deenergized, and if, when contact 6 of time release TR becomes closed, no train has entered the section to the left of section B--C, lamp W will become lighted. The time required for contact 6 of time release TR to close is so chosen that if a train is approaching the section to the left of section BC within a distance which is less than braking distance, the train will have entered the section before contact 6 becomes closed in which event track relay R will become deenergized and will interrupt the circuit that was previously closed for relay E thus deenergizing this relay and hence preventing the lamp W from becoming lighted. If lamp W does become lighted, the operator knows that it is safe to reverse the switch E and he then does so. As soon as the train moves out of the siding D and into section BC, the resultant deenergization of track relay R interrupts the stick circuit for relay E and thus causes this relay to become deenergized, and when the train has completely departed from section BC, the operator restores the switch S to its normal position. He also restores time release TR. to its normal position. The picking up of relay E in response to the operation of push button P of course, deenergizes signal control relay SC and causes signal S to moveto its stop position, so that if a train enters the section to the left of point B after lamp W has become lighted, the train will be compelled to stop when it reaches section BC. After the train which moved out of the siding D has departed from section BC if the section to the left of point B is still unoccupied, all parts will become restored to their normal positions in which they are shown in the drawings. It should be noted that if the trainman fails to restore the time release 'IR to its normal position when he restores the switch S to its normal position, signal S will remain at stop thus insuring that no train will enter section l3-C under these conditions.

The operation of the apparatus when it is desired to bring a train out of sidings D and D is similar to that just described and will be apparent from an inspection of the drawings without further detailed description. The operation of the apparatus when a train proceeds directly through section BC, or when it is desired to move a train from section B-C into one of the sidings, will also be apparent from an inspection of the drawings without further description. It should be noted, however, that when it is desired to move a train from section BC into a siding, it is unnecessary to operate the associated relay E in order to prevent a dangerous condition because as long as the train occupies the section, or the switch, or as long as any one of the switches S is reversed, signal S will occupy its stop position, and will thus prevent a following train from entering section BC under these conditions.

Under some conditions of operation it is considered safe to reverse a switch when section BC and the section to the left of this section are both unoccupied regardless of whether or not a train is then approaching the section to the left of section BC within a distance which is less than braking distance, and when this is the case the timereleases TR, and the lamps W may be dispensed with, each lamp G in this instance being connected directly in multiple with the associated relay E in such manner that each lamp G will be energized whenever the associated relay E is energized. The operation of the apparatus as a'whole when the circuits are modifled: in this manner will be apparent from the foregoing description without further detailed description. I

If desired, the relays E may be of the type which are provided with a mechanical indicator in the form of a miniaturesignal or the like, and when this type of relay is employed, the lamps G and W and the time releases may all be dis-' pensed with.

..Referring now to Fig. 2, the apparatus here shown includes all of the apparatus shown in Fig. 1 with the exception of the indication lamps and the time releases, and in addition, this apparatus includes three switch locks L L and L one of which is associated with each of the switches S S and S and three lock releasing subsections a b a -.b and a -b which are formed in the section BC adjacent the switches S S and S respectively, for a purpose which will be made clear presently. The switch locks L L and L are all alike and a description of one will, therefore, suffice for all. Referring particularly to the lock L this lock comprises a lock bar K which is rigidly secured to the switch S for engagement by a dog M by means of which the switch may be locked in its normal position in which it is shown in the drawings. Dog M is actuated by a manually operable lever H which is fixed to a shaft, indicated by the broken line in the drawings, and which may be rocked between normal and reverse positions, indicated by the reference characters 11 and 1", respectively. The shaft 25 carries a plurality of contacts 26, 21, and 28 which are closed when and only when the lever H occupies its normal position, and a latch segment 29. The latch segment 23 is provided with a notch 29*, and cooperates with' a latch dog 36. .The latch dog 30 is controlled by a magnet G in such manner that when the lever H occupies its normal position in which it is shown in the drawings, and the magnet-G is deenergized, the latch dog 30 will drop by gravity to a position in which it enters the notch 29, but that, when the magnet G is energized, the dog 30 will be attracted by the magnet to a position in which the dog is withdrawn from the notch 29*. It is, of course, obvious that when the dog 30 occupies the notch 29 movement of lever H away from its normal position is prevented, but that, when the dog 30 is withdrawn from the notch 29*, the lever H is then free to move between its two extreme positions. Operatively connected with the latch dog 30 is a contact 3! which is closed or open according as the latch dog occupies its looking or its unlocking position.

Each lock releasing subsection al-b is formed in the section BC by means of additional insulated joints 2 which are provided in the rails l and I and each subsection extends from a point. just in rear of the associated switch to a, point which is just far enough in advance of the associated switch to permit a train to shunt the subsection after the train has. cleared the switch. 1 Eachsubsection is provided with a track circuit including a track battery 3 and a track relay designated by the reference character R with an exponent corresponding to the exponent for the reference character of the associated switch. The railsof section BC on opposite sides of each subsection are connected together by suitable conductors 32 and 33 in a manner which will be readily understood from an inspection of the drawings.

Themagnet G of each lock L is provided with two pickup circuits, one of which includes a front contact 34 of the associated relay E, and the other of which includes a back contact 35 of the track relay for the associated sub-section and a contact 36. The circuits for the magnets G will be obvious from an inspection of the drawings without further description. Each contact 36 is 'of well-known type which isoperated by the door of the case in which the associated lock is 7 located in such manner that the contact will be open when the door is closed, but will be closed whenever the door is open sufficiently to permit access tothe associated lock lever H.

Relay E is provided with a pickup circuit which is controlled'by the push button P, by each of the locks L, by the relays E and E and by the two track relays R and R and which passes from terminal BX of the source through front contact 36 of track relay R line wire 31, front 7 contact 38 of track relay R back contact I l-l of relay E wire 39, contact 3| of magnet G of lock L contact 21 of lever H wire 40, back contact ll-i l of relay E wire 4|, back contact 3| of magnet G of lock L contact 28 of lever H line wire 42, push button P and the winding of relay'E to terminal CX.

Relay E is provided with a pickup circuit which is controlled by the push button P, by the locks L and L by the relays E and E and by the track relays R and R and which passes from terminal BX through front contact 36 of track relay R wire 31, front contact 38 of track relay R back contact H-ll of relay E wire 39, contact 3! of magnet G of lock L lever contact 2'! of lock L wire 4!), push button P the winding of relay E wire 43, contact 21 of lever H cf-lock L contact 3| of magnet G of lock L and back contact 44 of relay E to terminal CX.

Relay E is provided with a pickup circuit which is controlled by push button P by the locks L and L by the relays E and E and by. the track relays R and R and which passes from terminal BX through front contact 36 of track relay R wire 31, front contact 38 of relay R push button P the winding of relay E wire 45, contact 2'! of lever H of lock L wire 46, back contact 44 of relay E wire 43, contact 21 of lever H of lock L contact 3| of magnet G of lock L1, and wire 44 to terminal CX.

Each relay E is also provided with a stick circuit which is similar to the pickup circuit traced above with the exception that this latter circuit includes front contact l l--! i of the relay in place of the associated push button P.

It will be seen, therefore, that if it is desired to energize one of the relays E, this may be done by depressing the associated push button P providing the track section BC and the section V the lock L to the left of this section are both unoccupied, the two remaining relays E are both energized, and the locks controlled by these relays both occupy their locking positions. It will also be apparent that when the relay E becomes energized, the closing of its front contact will complete its stick circuit, and will thus cause the relay to remain energized until a train enters either section 13-0 or the section to the left of this section, at which time the resultant deenergization of the track relay R or the track relay R", as the case may be, will interrupt the stick circuit for the relay, and will thus cause the relay to become deenergized.

Signal control relay SC is provided with a circuit which passes from terminal BX through front contact 51 of track relay R front contact 48 of track relay R wire 49, contact 26 of lever H of lock L wire 50, back contact 2! of relay E switch operated contact F front contact at of track relay R wire 5!, contact 25 of lever H of lock L wire 52, back contact 25 of relay E switch operated contact F front contact 43 of track relay R wire 53, contact 26 of lever H of lock L wire 55, back contact 2! of relay E switch operated contact F and the winding of relay SC to terminal CX. It will be seen, therefore, that the signal control relay SC will be energized whenand only when section B -C and each of the subsections which are located in this section are all unoccupied, and the switches S S and S all occupy their normal positions and are locked in these positions. The relay SC controls the signal S in the same manner as in Fig. 1.

In explaining the operation of the apparatus shown in Fig. 2 as a whole, I will first assume that it is desired to permit a train to enter the siding D To do this, the engineman will move his train to the position in which the rear end of the train is past the switch, but is still effective to shunt the lock releasing subsection a b and a trainman will then open the door of the cover for When the trainman does this, since the track relay R will then be deenergized due to the presence of the train in look releasing section a b the resultant closing of the contact 36 controlled by the door of the lock L will complete one of the pickup circuits for the magnet G and this magnet will, therefore, become energized, and will thus move the locking dog 30 to its unlocking position. When the locking dog reaches its unlocking position, the trainman will then move the lever H from its normal position 11 to its reverse position 1' which movement will withdraw the dog N from the lock bar K thus unlocking the switch. When the switch becomes unlocked, the operator may then move it to its reverse position, thus permiting the trainman to back his train into the siding D As soon as the train clears the fouling point, the track relay R will become deenergized and will thus interrupt the pickup circuit which was previously closed for the magnet G Thismagnet will, therefore, become deenergized, and, as a result, if the operator then restores the switch to its normal position and the lever H to its normal position, the switch will become relocked in its normal position. It should be noted that when lever H is moved to its reverse position, all circuits for relays E and E are then open, so that these relays are prevented from becoming energized under these conditions. the circuit for signal control relay SC is open, so that signal S will occupy its stop position.

Furthermore,

The operation of the apparatuswhen it is desired to move a train from section B--C into either of the other sidings is similar to that just described and will be apparent from an inspection of the drawings without further description.

I will now assume that a train has been moved into the siding D in the manner previously described and the switch S has been subsequently restored to its normal position and locked in this position, and that it is now desired to move the train out of the siding into the section B--C. To permit this to be done, the trainman will depress the push button P and if section BC and the section to the left of this section are then both unoccupied, the pickup circuit for relay E will become closed, whereupon this relay will become energized and will complete its stick circuit. The energization of relay E will complete the pickup circuit for relay G including front contact 34 of relay E and magnet G will, therefore, become energized and will unlock the lever H As soon as this lever becomes unlocked, the operator will then move the lever from its normal to its reverse position to unlock the switch in the manner previously described, and after the switch has become unlocked, he will then move the switch from its normal position to its reverse position. With the switch in its reverse position, the train may then proceed into section 3-6. As soon as the train passes beyond the subsection (I -b the resultant deenergization of track relay R will interrupt the stick circuit for relay E and relay E will, therefore, become deenergized. Magnet G however, will remain energized until the train has passed completely out of the subsection a b by virtue of the pickup circuit for magnet G including back contact 35 of relay R and the associated door contact 36. As soon, however, as the train has cleared the subsection a b magnet G will then become deenergized, and, as a result, if the operator then restores the switch to its normal position and the lever H to its normal position, the switch will become relocked in its normal position in an obvious manner. When the train has passed completely out of section BC, all parts will then be restored to their normal positions in which they are shown in the drawings. It should be noted that as long as switch S occupies its reverse position, the circuit for signal control relay SC will be open at theswitch operated contact F thus insuring that signal S will remain in its stop position under these conditions. It will also be noted that when the train occupies either subsection a b or section 13-0, the circuit for relay SC will also be open, and it follows, therefore, that under no conditions will a dangerous condition exist due to a movement of a train into or out of the siding D The operation of the apparatus shown in Fig. 2 when it is desired to move a train out of the sidings D and D is similar to that just described and will be apparent from an inspection of the drawings without further description.

Referring now to Fig. 3, as here shown, the push buttons P shown in Fig. 2 have each been replaced by an associated door operated contact 56 connected in series with the contact 6 of an associated time release TR. The door operated contacts 55 are each similar to the associated door operated contact 35 while the time releases TR are each similar to the time releases shown in Fig. 1. Furthermore, as shown in Fig. 3, a contact 5 of each of the time releases has been included in the circuit for the signal control relay SC. The remainder of the apparatus shown in Fig. 3 is similar in all respects to that shown in Fig. 2.

With the apparatus constructed as shownflin Fig. 3, the operation of the apparatus when it is desired to permit a train to enter a siding is the same as the operation of the apparatus shown in Fig. 2. 'When it is desired to move a train out of a siding, however, it is necessary for the trainman to first open the door of the associated lock,

and to then operate the associated time release 'I'R; The operation of the time release interrupts at its contact 5 the circuit for the associated signal control relay SC, and thus causes signal S to move to its stopposition. The operation of the associated time release also prevents the associated relay E from picking up if a train is within less than braking distance of the section to the left of section 3-0 when the release is set into operation, for the reason that the circuit for relay E will not become closed untilafter the time contact 6 of the release has become closed, and if the train is within less than braking distance of the section to the left of section B-C when the release is set into operation, by the time the contact 5 has become closed, the train will have entered the section to the left of section B-C and will thus have caused track relay R to become deenergized and open the circuit for the relay E. After the associated relay E has once become picked up, the remainder of the operation will be similar to that previously described in connection with Fig. 2 with the exception that after the train has entered section B--C and the switch has been restored to its normal'position, it'is necessary for the trainman to restore the time release to'its normal position to permit signal S to clear when the train subsequently passes out of section BC.

Although I have herein shown and described only three forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

-Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track divided into sections, a plurality of switches connected with one of said sections, a track circuit for said one section including a track relay, a signal for governing the entrance of trafiic into said one section, a plurality of control relays one associated with each switch; a pickup circuitfor each control relay including a manually operable contact, a front contact of said track relay and a back contact of each of the other control relays, an indication means controlled by each relay, and means for controlling said signal controlled by all of said relays.

2; In combination, two adjacent sections of railway track, a track circuit for each of said track sections including a track relay, a plurality of siding's connected with one of said sections by means of track switches, a control relay associated with each switch, a push button associated with each control relay, a time release associated with each switch, each said time release comprising first and second normally closed contacts which become opened immediately when the release is set into operation and a normally open contact which becomes, closed at the expiration of a predetermined time interval after the release is set into operation; 'a pickup circuit for each control relay including the associated push button, a front contact of each'of said track relays; and a back contact of each of the other control relays; a stick circuit for each control .relay including its own front contact, a front contact of each of said track relays, and a back contact of. each of the other control relays; first and second indication devices associated with each control relay, means for connecting each of said first indication devices in multiple with the associated control relay over the first normally closed contact of the associated time release, means for connectingv each of said second indication devices in multiple with the associated control relay over the normally open contact of the associated time release, and a signal for controlling the entrance of trafiic into said one section controlled by the track relay for the section, by each of said control relays, and by the second normally closed contact of each of said time releases.

3. In combination, two adjacent sections of railway track, a track circuit for each of said track sections including a track relay, a plu rality of sidings connected with one of said sec tions by means of track switches, a control relay associated with each switch, a push button associated with each control relay, a time release associated with each switch, each said time release comprising first and second normally closed contacts which become opened immediately when the release is set into operation and a normally open contact which becomes closed at the expiration of a predetermined time interval after the release is set into operation; a pickup circuitfor each control relay including the associated push button, a front contact of each of said track relays, and a back contact of each of. the other control relays; a stick circuit for each control relay including it own front contact, a front contact of each of said track relays, and a back contact of each of the other control relays; first and second indication devices associated with each control relay, means forconnecting each of said first indication de-' vices in multiple with the associated control relay over the first normally closed contact of the associated time release, means for connecting each of said second indication devices in mul of each of said control relays, and said switch operated contacts; and a signal for governing the entrance oftrafiic into said one section controlled by said signal control relay.

4. In combination, a stretch of railway track including a plurality of switches, a signal adjacent one end of said stretch for governing trafiic movements into said stretch in one direction, a relay associated with each switch, means for controllingeach relay in such manner that the relay cannot be energized unless said stretch is unoccupied and the remaining relays are all deenergizerl, and means controlled by said relays for controlling said signal.

5. In combination, a main section of railway track, a plurality of sidings connected with said main section by means of switches, a plurality of subsections formed in said main section, one at each of said switches, means for connecting the rails of said section together on opposite sides of said subsections, a track circuit including a track relay for said main section and for each of said subsections, a control relay associated with each switch; a pickup circuit for each control relay including a push button, a back contact of each of the other control relays, and a front contact of the track relay for said main section; a stick circuit for each control relay in cluding its own front contact, a back contact of each of the other control relays, and a front contact of the track relay for said main section, and an electric lock for each switch controlled by the associated control relay and by the track relay for the associated subsection.

6. In combination, a main section of railway track, a plurality of sidings connected with said main section by means of switches, a plurality of subsections formed in said main section, one at each of said switches, means for connecting the rails of said section together on opposite sides of said subsections, a track circuit including a track relay for said main section and for each of said subsections, a control relay associated with each switch; a pickup circuit for each control relay including a, push button, a back contact of each of the other control relays, and a front contact of the track relay for said main section; a stick circuit for each control relay including its own front contact, a back contact of each of the other con trol relays, and a front contact of the track relay for said main section; an electric lock for each switch controlled by the associated control relay and by the track relay for the associated subsection, and a signal for said main section con-- trolled by all of said relays and by all of said locks.

'7. In combination,a main section of railway track, a plurality of sidings connected with said main section by means of switches, a plurality of subsections formed in said main section, one at each of said switches, means for connecting the rails of said section together on opposite sides of said sub-sections, a track circuit including a track relay for said main section and for each of said subsections, a control relay associated with each switch; a pickup circuit for each control relay including a push button, a back contact of each of the other control relays, and a front contact of the track relay for said main section; a stick circuit for each control relay including its own front contact, a back contact of each of the other control relays, and a front contact of the track relay for said main section, a lock for each switch provided with a manually operable lever for releasing the lock and with a magnet which must be energized to permit operation of the lock and with a contact which is open or closed according as the door which permits access to the lock lever is closed or open, means for controlling the magnet of each lock controlled by the associated control relay, and other means for controlling the magnet of each lock controlled by the track relay for the associated subsection and including the associated door operated contact.

8. In combination, a main section of railway track, a plurality of sidings connected with said main section by means of switches, a plurality of subsections formed in said main section, one at each of said switches, means for connecting the rails of said section together on opposite sides of said subsections, a track circuit including a track relay for said main section and for each of said subsections, a control relay associated with each switch; a pickup circuit for each control relay including a push button, a back contact of each of the other control relaysyand a front contact of the track relay for said main section; a stick circuit for each control relay including its own front contact, a back contact of each of the other con-v trol relays, and a front contact of the track relay for said main section, a lock for each switch proprovided with a manually operable lever for releasing the lock and with a magnet which must be energized to permit operation of the lock and. with a contact which is open or closed according as a door which permits access to the lock lever is I closed or open, means for controlling the magnet of each lock controlled by the associated control relay, other means for controlling the magnet of each lock controlled by the track relay for the associated subsection and including the associated door operated contact, and a signal for said main section controlled by all of said relays and by all of said locks.

9. In combination, a main section of railway track, a plurality of sidings connected with said main section by means of switches, a plurality of subsections formed in said main section, one at each of said switches, means for connecting the rails of said section together on opposite sides of said subsections, a track circuit including a track relay for said main section and for each of said subsections, a control relay associated with each switch; a time release associated with each switch, each said time release being provided with a normally closed contact which becomes opened as soon as the release is set into operation and with a normally open contact which becomes closed at the expiration of a predetermined time interval after the release is set into operation, a lock for each switch including a manually operable lever for releasing the look, a magnet for preventing operation of the lever except when the magnet is energized and two door operated contacts which are closed or open according as a door which permits access to the lock lever is open or closed; a pickup circuit for each control relay including one of the associated door contacts, the normally open contact of the associated time release, a back contact of each of the other control relays, and a front contact of the track relayfor said main section; a stick circuit for each control relay including its own front contact, a back con-

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