US927404A

US927404A - Block-signal system.

Info

Publication number: US927404A
Application number: US30843206A
Authority: US
Inventors: Albert G Davis
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1906-03-28
Filing date: 1906-03-28
Publication date: 1909-07-06
Anticipated expiration: 1926-07-06

Description

A. G. DAVIS. BLOCK SIGNAL SYSTEM.

APPLIOATION FILED MAR. 28, 1906.

Patented July 6, 1909.

W/Z'nesses UNITED STATES PATENT OFFICE.

ALBERTYG. Davis, or SGHENECTADY, New YORK, assronoa T0 GENERALELECTRIC con- PANY, A CORPORATION or NEW YORK.

BLOCK-SIGNAL SYSTEM.

Specification of Letters Patent;

Patented .ru' e, 1m.

tems for electrically-operated roads employing the rails for the return conductor for the power-current. Such roads have been installed heretofore with the'rails pro erly sectioned to i'ormblocks for the signs -current, and with connections between the blocks adapted to transmit the power-current but so arranged as. to revent the flow of si alcurrent from one b ock to another. Suc an arrangement .is easily secured for a single track, but it sometimes hap ens in the case ofroads having parallel trac ks that it is. desirable to cross-connect the two or more tracks so as to improve theconductivity of the system for the power-current. For instance, if the resistance of the rail-oircuit 'of a block ishigh, owing to defectivebonding,

this will introduce a loss in the power-circuit if the tracks are not cross-connected, but with the cross-connections, the other tracks serve as a low-resistance shunt forthe defective rail-circuit. When such cross-connectionsare employed, however, a difficulty 'is introduced in guarding against broken rails. Since the rails of one block are shunted by the rails of the-parallel block or blocks, a

, broken rail will not open the signal-circuit,

and consequently, with a system as ordinarily arranged, thesignal for a block may indicate clear. in spite of a broken rail in the block. danger, and the object of my invention is to reduce the possibility of accident from this 1 power-current, either thirdr'ails or trolley The rail ci-rcuit of the block A is supplied with alternating-current by a transfailure of current in either winding. Ob-i viously, if there is a break in either rail, one of the twowindings' must be open-circuited; and by so arranging the signal apparatus that the signal is putat d'an er upon the failureof current in either win ing, absolute protec- This is obviously a source of fore in the case of direct-ourrentroads to em} ploy alternating-current for the si al-circuits, since by so doing interference etween the power and signal-currents may readily be avoided.

My invention, as applied to roads having alternating-current si nal systems, further comprises arranging the windings between the cross-connection from the other track to a the rails of the block, asv primary transformer windings, and solarrangin the second trans former windings and the re ays supplied therefrom that the signal is putat danger when eithegiprimary transformer winding, is deemerg1z Still more specifically, my invention consists in vplacing both .primary transformer arrangin the core that a 'portion'of it is traverse by an alternating flux only upon an unbalanoing of the alternating signal curviding a secondarywindin on that portion 'of the magnetic circuit wit 1 means supplied from the secondary winding for putting the signal at ;danger.

reference to the accompan' ing drawing,

which shows diagrammatlcal nal system arranged in accordhnce with my invention. a

I have illustrated and shall describe my invention as applied to a road employing alternating-current for the si a1 circuits, but it will be understood that-1n its broader altitrnkting-current system.

In the drawin A A represent the rails of road.

B B represent supply conductors for the netic member eopposite the three limbs of the 'E-shapedmember, but separated from tion is secured. I It has been proposed heret o windings on the" same magnet, core, and so rent in the two. primary windings, and pro- My invention will best be understoodby a block Si l I raspect my invention is not limited to an 7 two parallel bloc s of an electrically-operated across the rails and the primary of which is connected to the alternating-current lme- 10s comprises an E-shaped member and a mageach of the limbs by an air-gap. Two coils F F are placed on the two outer limbs of the E-shaped member and are connected in series across the rails A. These coils are so wound that the alternating signal current passing through them produces a flux which passes in series through the two coils and through the member e. With equal currents flowing through the two windings F the. middle limb of the E-shaped memberis not traversedby any alternating flux. Secondary windingsf 7"are placed in inductive relation to the windings F F and supply a coil G of the track relay. This relay is shown as of the two-phase induction type, since this form of relay is not affected by an unbalanced fluctuating power-current in the windings F F. The other primary coil H of the relay is supplied directly or through a transformer from the alternatingcurrent line-wires D.

-The short-circuited secondary member of the relay carries a contact which, when both prlmary relay cells are energized, closes a circuit through the source of current I and r the operating mechanism J of the signal K. This 0 crating mechanism .is merely indicated diagrammatically, and may be of any well-known type.

It will be seen that the point of connection between the two coils F F is connected to the central point ofthe secondary winding of the transformer supplyin the adjacent block of the same track, and a so to the opposite track. This connection is made of sufficient cross-section to carry the power-current, as are also the transformer windings connected tothe track. The power-current coming from the adjacent block of the same track, or from the opposite track, normally divides substantially equally between the coils F F, assing through the rails A in parallel. T e magnetomotive forces due to this current in the coils F F oppose each other in the member e and assist each other in magnetizing the central limb of the E-shaped member. The air-gaps between the E-shaped member and the'member e ar'efor the purpose of preventing saturation of the core by the power-curren With a system as thus far described, it will be seen that a break in one of the rails A, as, for instance, at X, may not cause the signal K to indicate danger, since current will flow from the central point of the secondary of transformer 0 through the cross-connection to the opposite block through the windings F F in parallehthrough the rails A. in parallel, throu h the two portions of the secondary win 'ng of transformer C in opposite directions, to the cross-connection,-

thence through the right-hand coil F and through the lower rail A to the right-hand terminal of the secondary of transformer. C. This current in the winding F may be sufficient to energize the secondary winding f, and

'otl1er.relay,'the' contacts of which are normally closed, and are included in the signalo)erating mechanism. This signal is also s iown as of the polyphase induction type,- having a second winding N su plied from the line-wires D, so that-fluctuatlons of the flux reduced bythe power-current in the central imb of themagnetic member E will not operate the relay. -It will be seen that with current flowing through only one of the windings F, as, for instance, the right-hand winding, as would be the case if a rail were broken atX, the alternating flux due to the current in the right-hand winding F will divide between the left-hand central limbs ofthe member E. This flux will consequently energize the relay winding M so as to actuate the relay to open the signal-circuit. This actuation of the relay will occur upon the deener izing of either of the coils F, sp that a brea in either rail of the block A will produce a danger indication of the signal.

I do not desire to limit myself to the particular construction and arrangement of parts here shown, but. aim in the appended claims to cover all modifications-w 1ch are within the scope of my invention.

'What I claim as new and desire to secure by Letters Patent of tlie United States, is:

1. In a signal system for electrically-operated roads having parallel tracks, a connec tion from a block to the parallel track adapted to form a path for the power-current, two windingsinserted respectively between the rails of the block and said connection, a signal for said block, and means operative upon the failure of current in either winding for causing said signal to indicate danger.

2. In a signal system for electrically-operated roads having parallel tracks, a comet:-

tion'from a block to the parallel trackadapted to form a path for the power-current, two

windings inserted respectively between the rails of the block and said connection, a signal for said block, electric operating mechanism therefor, and means operative upon the failure of current in'either of said windings v for breaking the circuit of said operating mechanism.

3. ha signal system for electrically-operated roads having parallel tracks," a connection from a block to the parallel track adapted to form a path for thepower-current, two windings inserted respectively between the rails of the block and said connection, a signal for said block, electric operating mechanism therefor, and relay contacts in'circuit with ication with a broken rail in 70 break the circuit of said operatingmechanism upon winding.

4. In a signal system for electrically-operated roads having parallel tracks, means for supplying alternating-current to the rail circuit; of a block, a connection from the block to the opposite track adapted to form a path forthe power current, two inductive windings inserted respectively between the the failure of current in either rails of said block and said connection, a

signal for said block, and means operative upon the failure of current in either of said windings for causing said signal to indicate danger. w

5. In a signal system for electrically-operated roads having parallel tracks, means for supplying alternating-current to the railcircuit of a block, a connection from the block to the opposite track adapted to form a. path for the power-current, two primary transformer windings inserted respectively between the rails of the block and said connection, secondary windings inductively re lated to said primary windings, relays supplied from said secondary windings, and a signal controlled by said relays, said secondary windings and relays being arranged to cause saidsignal to indicate danger upon the failure of current in either primary Winding.

6. In a signal system for electrically-operated roads having parallel tracks, means for supplying alternating-current to the railcircuit o l a block, a connection from the block to the opposite track adapted to form I a path for the power-current, a magnetic circuit, two windings on said magnetic circult inserted respectively between the rails of the block and said connection and arranged to produce a change of flux distribution in said magnetic circuit upon a failure of current in either winding, a signal for the block, and means responsive to said change in flux distribution for causing the signal to indicate danger 7. In a signal system for electrically-opated roads having parallel tracks, means for supplying alternating-current to the rail-on cuit of a block, a connection from the block to the opposite track adapted to form a path for the power-current, a magnetic circuit, two windings on said magnetic circuit inserted respectively between the rails of the block and said connection and arranged to produce a change of flux distribution in said magnetic circuit upon a failure of current in either winding, secondary, windings on said magnetic circuit, relays supplied from said sec ondary windings, and a signal for theblock controlled by said relays, said secondary windings and said rela s bein arranged tocause the signal to indicate f anger upon a path for the power-current, two windings inserted respectively between the rails of the block and said connection, a magnetic circuit for said windings having a portion traversed by an alternating flux only uponan unbalancing of the alternating-current" in said windings, a secondary winding carried on said portion of the magnetic circuit, a signal for the block, and means for causing said signal to indicate danger upon a how of current in said secondary winding.

9. In a signal system for electrically-operated roads having parallel tracks, means for supplying alternating-current to the rail circuit of a block. a connection from the block to the opposite track adapted to form a path for the power-current, two windings inserted respectively between the rails of the block and said connection, a magnetic circuit for said windings having a portion traversed by an alternating flux only upon an unbalancing of the alternating-current in said windings, a secondary winding carried on said portion of the magnetic circuit, a signal for the block, and a relay connected to said secondary winding and controlling said signal.

10. In a signal system for electrically-operated roads having parallel tracks, means for supplying alternating-current .to the rail-circuit of a block, a connection from the block to the opposite track adapted to form a path for the power-current, two windings inserted respectively between the rails of the block and said connection, a magnetic circuit for said windings having a portion traversed by an alternating liux only upon an unbalancing of the alternating-current in said windings, a secondary winding carried on said portion of the magnetic circuit, a signal for the block, and a. relay coil connected to said secondary winding and arranged when energized to cause said signal to indicate danger,

11. In a signal system for electrically-operated roads having parallel tracks, a connection from a block to the opposite track adapted to form a path for the power-current, two windings mserted respectively between the rails of the block and said connection, a magnetic circuit for said windings having a portion traversed by'a flux due to the current in said windings only upon an unbalancing of said current in said windings, a signal for the block, and means responsive to the flux in said portion for causing the signal to indicate danger.

12. In an alternating-current signal system, a source of alternating-current confor the block, and means for causing said balancing of the alternating-cui'rcnt in said nected to the rails of a block, two windings connected in semes' across sald mlls, a signal signal to indicate danger upon an unmezins for causing the sign-cl to indicatedanger upon an ,unlmlnncing ol' the altern: |.t111g c1n'|'c11t 1n szud windings. E

14.'ln an ailtci'lmtmg-curl'cnt signal 'sys- 1 having two across said ran s, a mugnetlccu'cuit [or said term a source of alternating-current connected to the rails of a block, a transformer rlmzn'y windings connected windings \h aving a portion traversed by :L flux due to. the current'in said windings only upon'sn'unbalancing of said current in said windings, a signal for the block, and mezms responsive-to the flux in said o1-tion for causing the signal to indicate dungel In witness whereof, I have hereunto set my hand this-26th day of Mural], 1906.

' AlJBlQWl (l. DAV 15. W itncsses BIGUJAMIN B. ll'uui, llnLnN ()l n onn.