US799816A - Block-signal system. - Google Patents

Description

No. 799,816. PATENTED SEPT. 19, 1905.

H. E; WHITE.

BLOCK SIGNAL SYSTEM.

APPLICATION FILED FEB. 11. 1904.

Witnesses: Inventor:

Harold E. White mmiu. r Qumm 50.. FNOTWLIIMOGRAPHERS. WASNYNGYON o. a

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HAROLD E. WHITE, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

BLOCK-SIGNAL SYSTEM.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application filed February 11, 1904:. Serial No. 193,086.

tems; and the object of my invention is to pro vide a novel signal system comprising as one of its elements a novel form of relay which remedies a defect in operation which has existed in such systems as heretofore arranged.

In a block-signal system in which home and distance signals are used it is customary to operate the relays for the home signal for a given block from the same source of current which operates the distance-signal for the following block, the home signal being controlled by an ordinary relay the operation of which depends merely on the flow of current regardless of direction and the distance-signal being controlled by a polarized relay the operation of which depends upon the direction of the current. In this arrangement in order to secure the proper operation of the polarized relay it is necessary that the current through it should be reversed whenthe distance-signal is to operate. This necessitatesa reversal of current through the relay for the home signal also, and during the reversal of flux there is an instant when the flux is zero, which produces a momentary shifting of the home signal. This shifting of the home signal may under some circumstances cause the engineer of an approaching train to stop his train wholly unnecessarily. By my invention this shifting of the home signal upon the operation of the distance-signal is done away with and the chance of needless stops eliminated.

My invention will be best understood by reference to the accompanying drawing, in which A A A represent three blocks of a railway system.

B and B represent two semaphore-posts at the entrance to blocks A and A, respectively. Each semaphore-post carries a home and distance signal, (indicated by Hand D, respectively.) Thus the home signal for block A is indicated by the semaphore-arm H on sema phore-post B. The distance-signal for the same block isindicated by semaphore-arm D on semaphore-post B. The drawing indicates the position of the signals on the assumption that a train is in block A. The relay E is short-circuited, allowing its armature e to fall. This opens the circuit of the operating mechanism for the home signal H, allowing the signal to go to danger position by gravity. The operating mechanism for signal H is merely indicated by m, since many forms of electrical operating mechanisms are well known in the art and form no part of the present invention.

Home signal H controls by its movement reversing-switch S in the circuit of battery b, which supplies the current for the relays connected to block A. When home signal H is in the danger position, switch S is in the proper position to produce a flow of current through polarized relay F of proper direction to deenergize the relay and to open the circuit of the operating mechanism at of distance-signal D. Thus home signal H and distance-signal D are in the proper position to show the presence of a train in block A. Current is flowing through relay E, which operates regardless of the direction of currentflow. Relay E thus holds its armature up and maintains the circuit of operating mechanism m closed. Home signal H is accordingly held at safety, properly indicating that block A is clear. Now assume that the train in block A is passing out of the block and into the one beyond. The short circuit is removed from relay E, which draws up its armature e and closes the circuit of operat ing mechanism m, which restores signal H to safety. As signal H moves to safety position it draws up switch S and reverses the direction of current through the trackcircuit A. Polarized relay F is thus energized and draws up its armature f and operating mechanism a restores distance-signal D to safety. Signals Hand D are then in the proper position toshow that block A is clear; but in reversing the current through relay F the current through relay E is also reversed. This produces a reversal of flux in relay E,during which there is an instant when the flux is zero. At this instant armature 0 falls, opening the circuit of operating mechanism m, and consequently signal H goes to danger by gravity. Although signal His restored to its proper position the next instant, there is a chance that the engineer of an approaching train may glance at the signal at the instant it goes to danger. Upon seeing a home signal at danger the engineer may apply the emergency-brake, thinking a train to be in the block he is entering, while in reality the train is two blocks beyond, and a stop is wholly unnecessary. This defect in the operation of the system is eliminated by the novel form of relay whichI employ for controlling the circuit of the operating mechanisms for the home signals.

each consist of an E-shaped magneticcore, forming with the armature two magnetic parts or circuits, on one part of which is mounted the coil 2', which is connected to the track-circuit. The coil '5 corresponds to the relay-operating coil as ordinarily used. In addition to coil two other coils j and 7a are placed upon the core E. Coil j is placed on the same portion of the core as coilz' and being in inductive relation thereto acts as asecondary for coil z' and is energized by any fiuctuation of current in coil '5. Coil k, which is mounted on the other part of the core forming the second magnetic circuit, is connected in series with coil j and is traversed by any current induced in. coil j. The operation is then as follows: Assuming the circuit of coil 2' to be opened suddenly, the variation in magnetic flux produced by the sudden variation of current induces an electromotive force in coil which causes a current to flow through coil This current produces a magnetization of the portion of the core on which coil is is mounted, which is displaced in phasefrom, the magnetization produced by coil 2' and maintains armature c in its raised position during the instant that the magnetization of coil '6 passes through its zero value. The effect of coil is is of course only instantaneous; but by the time its effect has died away coil is again energized and continuously maintains armature e in its raised position. The effect of coil is therefore serves to bridge over the instant during which coil is deenergized by the reversal of current. Consequently all danger of the signal controlled by relay E going to safety position upon an instantaneous reversal of current is eliminated and a serious defect in operation is removed- While I have shown a simple form of relay well adapted to secure the object of my inven tion, it will be understood that its formlmay be considerably altered without departing from the spirit of my invention. For instance, although I have shown two magnetic circuits having onepart in common, it is not necessary that they should possess this feature, and the shape of .the magnetic circuits may be much altered without affecting the operation. Accordingly I do not desire to limit myself to the particular construction and arrangement of parts here shown, since changes which do not depart from the spirit of my invention and which are within the It will be seen from the drawing that relays E and E'- scope of the appended claims will be obvious to those skilled in the art.

What I claim as new, and desire to secure by Letters Patent of the United States, is- 1. In combination, an electric circuit, a

' switch member adapted to open said circuit,

a relay adapted when energized to maintain said switch member in its closed position, a coil adapted to energize said relay, and a second coil arranged to be energized upon a variation of current in the first-named coil and adapted tomaintain said circuit closed during an instantaneous reversal of current in the first-named coil.

2. In combination, an electric circuit, two relay-coils, two magnetic circuits arranged to be energized by said coils, respectively, means operative upon the energizing of either coil for maintaining said circuit closed, a source of current connected to one of said coils, and means for energizing the other coil upon a variation of current in the first coil.

3. An electric circuit, two relay-coils, means operative upon the energizing of either coil for maintaining said circuit closed, a source of current connected to one of said coils, means for reversing the relative connections of said coil. to said source, and means for energizing the other coil upon a reversal of current in y the first coil.

L. In combination, two magnetic circuits, a movable armature adapted to be restrained when either magnetic circuit is energized, a coil mounted on one of said magnetic circuits and connected to a. source of current, and a second coil mounted on the other magnetic circuit and arranged to be energized upon a variation of current-flow in the first coil.

5. In combination, two magnetic circuits, a movable'armature adapted to be restrained when either magnetic circuit is energized, a coil connected to a source of current and adapted to energize one of said magnetic circuits, and means for energizing the second magnetic circuit upon a variation of currentflow in said coil.

6. In combination, two magnetic circuits, a movable armature adapted to be restrained when either magnetic circuit is energized, a coil mounted on one of said magnetic circuits and connected to a source of current, a second coil arranged to be energized inductively upon ranged to be energized upon a reversal of current through the first coil.

8. A block-signal system, comprising ,a block-circuit, a source of current therefor, a polarized relay connected to said circuit, means for reversing the current through said circuit, and a non-polarized relay connected to said circuit and comprising two magnetic circuits each adapted when energized to maintain said relay closed, one of said magnetic circuits being energized by the current in said block-circuit and the other magnetic circuit being arranged to be energized during'a reversal of said current.

9. A block-signal system, comprising a block-circuit, a source of current therefor, a polarized relay connected to said circuit,

means for reversing the current through said circuit, and a non-polarized relay connected to said circuit and comprising two magnetic circuits each adapted when energized to maintain said relay closed, a coil connected on one of said magnetic circuits and connected to the block-circuit, a second coil arranged to be energized inductively upon a variation of current through the first coil, and a third coil mounted on the other magnetic circuit and connected in series with the second'coil.

In witness whereof I have hereunto set my hand this 9th day of February, 1903.

HAROLD E. WHITE.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

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