US870139A - Track-relay. - Google Patents

Description

PATENTED NOV. 5, 1907.

2 SHEETS-SHEET 1.

EE-s

J. D. TAYLOR. TRACK RELAY.

APPLIOATION FILED Arn.1a,1eo7.

PATENTBD NOV. 5, 1907.

J. D. TAYLOR.

TRACK RELAY.

APPLIGATION FILED APB.1a.19o7.

2 SHEETS-SHEET 2.

WITN ESSES fdl-1@ UNITED STAT ES PATENT OFFICE.

JOHN D. TAYLOR, OF SWISSVALE, PENNSYLVANIA, ASSlGNOlt TO UNION SWITCll Ik SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

TRACK-RE LAY.

Specification of Letters Patent.

Patented Nov. 5. 1907.

Application filed April 18. 1907- Serial No. 368 997.

To all 'who/m, 'it may concern:

Be it known that I, JOHN D. TAYLOR, of Swissvalc,

My invention relates to the operating of block signals controlled by track circuits. The principal object of the invention is to provide a relay which will operate only with a current of a given 4 frequency, and will prevent incorrect operation of the signal, either bythe unbalancing of the track circuit, by stray currents or otherwise. i

The invention consists in an induction motor cornbined with a centrifuge or similar device which is selective by reason of different speeds at whichit is driven by currents of different frequencies. This selective character is preferably imparted by a centrifuge, the speed of which must reach a certain predetermined rate before the signal can be operated.

The system is `especially advantageous for alternating current electric roadsystems, though it may be employed for roads operated by direct current, or for steam roads, or roads having other systems of propulsion. In the drawings, I show my invention as applied to an electric road having alternating current, both for the propulsion circuit and the signaling circuit.

Referring to Fig. 3, 2 represents -the trolley wire or third rail through which poweris transmitted to the train, 3 being the source of current supply for propelling the train. i 4 and 5 are sections of the railsforming what is known as a. block, 6, 7, 8 and 9 being sections of rails in the adjacent blocks. The insulation between the rails of the successive blocks is indicated at 11, 12,

. 13 and 14, this being preferably in the form of insulated 17 and 18v This connection to the middle point of the bond coil prevents any inductive action by the bond on the power current; while the bond oers an inductive resistance tothe track circuit current which is supplied to the track section by the secondary lcoil 19 of the track transformer. lhis rtrack transformer is shown as energized by having its primary coil 20 connected to the mains 21 and 22 leading from an alternating current generator' 23; and this generator has a current frequency greater than that of the generator 3.

The motor relay indicated at 24 is shown in detail in the preferred form, in Figs. l and 2. In these figursv25 is a laminated field piece of an induction motor of the squirrel cage type in which 26 indicates the laminated armature. The field piece is shown as having four inwardly-projecting poles each provided with an energizing coil. A copper band 27 known as a shading band is shown surrounding the corresponding half of each polar projection. this band being employed to cause'a lag of the magnetic flux in the part of the pole surrounded by it, resulting in a torque on the armature which causes it to rotate. The centrifuge portion of the relay comprises Weights 28 attached to levers 29 pivoted te and rotating with the tubular shaft 30 of the induc-V tion motor. Through the tubular armature shaft eX- tends a pin or rod 31, the lower end of which bears upon a bar 32 carried by links 32 depending from the centrifugal arms or levers. The rotation of the armature will cause the balls 0r weights to move outwardly and upwardly, and through the link connections will lift the bar 32 on which the rod 31 rests. 'Ihe rod 31 carries at its upper end, the contact lever 33, having a contact arranged to coact with the stationary contact piece'34. The contact will not `be made until'the shaft reaches a predetermined speed thereby moving the balls far enough to lift the contact lever 33 until the contact is made.

As shown in Fig. 3, the coils of the motor relay 24 are connected to the secondary 35 of a. second transformer whose primary coil 36 is connected to the rails 4 and 5 near the entrance of the block section by wires -or connections 37 and 38. 39 indicates the signal having a source of current 40 with the circuit wires 41 and 42.

The induction motor of the relay depends for its "speed solely o n the frequency of alternation; and the -the speed of rotation, so that it is an easy matter to differentiate between two current frequenciesby the, force tending to cause the weights to diverge. The parts 0f the apparatus therefore, can be so proportioned, that the force due to thelower frequency of alternation.

The force with which the y therefore, may or may notbe used, and in .wiilnot cause sufficient movement of the centrifuge arms to close the signal circuit; while if the motor isA driven at a higher speed at or ,above the certain limit, the contacts will be closed. For example, l may use a train propulsion current of the common frequency of twenty-,five cycles per second; while the current supplied'to the track signal circuit is ,sixty cycles per second. In this case, the motor willrotate 2.4 times as fast when lenergized by the track circuit current, as when energized by the unbalancing of the train propulsion current. The weights will therefore be thrown out with nearly six times as much force when driven at the higher 'of the .two speeds, than when driven at the lower.

In the operation of the system as shown, when there is no train in the block, the current from the secondary" coil "19 will flow through the rails 4 and 5 and -the primary coil 36 of the transformer. This will induce a current of the same frequency in the secondary coil'35 which will flow through the coils of the motor relay and cause a rapid rotation of its armature.l This will raise the centrifuge .arms and close v'the signal operating circuit at 34, thus ,clearing the signal. The inductive bonds 16 and 17 on acount of their reactance, will 'permit sufiicient difference of potential to be developed betweelithe rails 4 and 5, to cause the current to -fiow through the primary coil.36. When a train enters the block comprisingthe rails 6 and 7, the primary coil 36 of the transformer will be short circuited which will prevent the flow of current through. it, and accordingly prevent the induction of any current in the coil 35, thus depriving the motor relay of the power for rotating it. Its rotation will therefore cease, and the weights will return to their lower position, thus opening th'e signal circuit, and causing the signal to resume the danger position by gravity. In case there is unbalancing of the track circuit due to difference in the resistance of the rails 4 and 5,' current having the frequency of the train propulsion current, will pass through the primary coil36; and this may happen while a train is in the block comprising the rails 4 and 5; 4 This cul'- .rent will of course induce a current of the same frequency as the propulsion current, in the secondary coil 35. of the transformer; but the rotation of the motor relay caused thereby will be of too slow a rate to cause the closingof the signal vcircuit which will therefore not be cleared.

I have sho wn the transformer having the primaryl sion current. This transformer is, however, n'ot neces- I sary; and inmost cases, I prefer not to employ it, but

to connect the relay directly to the 4rails of the section.

I have .found in practicethat with the ordinary alternating'current .employedfor propulsion, no unbalancf 'ing which would ordinarily occur could interfere with the proper .operation of the relay. This transformer, most'cses would not be employed. k

The advantages of my4 nyention will be apparent to j those skilled in the art. Improper operation of the .the relay is operated with a much smaller current than is required with previous devices for this purpose. .The

relay will operate equally well whether the propulsion current is direct currentor alternating current.` Itmay also beused for steam roads or roads having other' systems of propulsion, where stray currents may be env neticallyinstead of mechanically, and many other changes may be made in the form of the selective speedv device portion'of the-relay, the circuits, etc., without departing from my invention, since I consider myself: the first to use a selective relay' wlio'sev operation depends upon its speed of rotation. V

I'claim2- I 1. Ina block signaling system, s track section con-i nected to a source of alternating current of high frevquency, and a relay comprising a motor whose speed of rotation is dependent on the frequency of. the current, av centrifuge driven by the motor, and a contact maker actuated by the centrifuge for closing -a signal c ircuit when the speed of rotation corresponds to the frequency of the tracir'clrcuit current.

2. In a block signaling system, a track section connected to a sourcel of alternatingv current having a frequency greater than that of any foreign 'current' in the track section, "and a relay comprising an. induction motor whose Aspeed of rotation is approximately proportioned to the frequency of the current supplied to'it, a centrifuge driven by the motor, and a contact maker a'ct'uated by the centrifuge for closing a signal circuit when thepeed of' rotation of the motor corresponds to the frequency of 4 the track circuit current nd isgreater than that corresponding to the frequency of the foreign current:

3. A frequency relsy'containing an induction motor and -a centrifuge together4 with-a'contact-making device actuated by the centrltugefor closing asignsl circuit lwhen 'the speed of rotation correspondsto thefrequency of thethe motor,-and a contact maker actuated by the centri; fuge for'closing a'signai circuit when thefspeed-of rota: .tlpn corresponds to .thefrequency of the track circult current substantially as described.

5. In a block eystem, a frequency relay containing an induction. motor, and a centrifuge, said motor receiving alternating current of s. certain frequency through' the track' circuit, which frequency is higher-'than 'any current which may be communicated by unbalancing of the prof ing current of higher .frequency than the propulsion curpulsion current or foreign currents; substantially as derent, and n relay having a speed device arranged to operseribed. ate a circuit when its speed reaches u predetermined rute;

'6. In a block signaling system, :1n insulatedtraek sec- 5 tion`c0nnected to a source of alternating current of high frequency, and a frequency relay having a speed selective device arranged to operate the signal circuit; substanl substantially us described. tially as described. r Witnesses In testimony whereof, I have hereunto set my hand.

JOHN D. TAYLOR.

7. In a block signaling system for electric railroads, an .ioHN MILLER, 10 insulated track section connected to a source `of alternat- H. M. ConWlN.

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