US1066681A - Electric car signaling system. - Google Patents

Description

J. W. TATUM.

ELECTRIC CAB SIGNALING SYSTEM.

APYLIGATION TILED MAR. 15, 1911.

Patented July 8, 1913.

2 SHEETS-SHEET 1.

J. W. TATUM.

ELECTRIC GAB SIGNALING SYSTEM.

APPLICATION IILED MARJS, 1911.

1,066,681 Patented July 8,1913.

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. UNITED STATESZATENT OFFICE.

JAMES W. TATUM, OF ANGIER, NORTH CAROLINA, ASSIGNOR OF ONE-SIXTH TO B. N. DUKE AND ONE-SIXTH TO W. FULLER .'0F NEW YORK, N. Y., AND ONE-SIXTH T0 E. J'. PARRISH, ONE-SIXTH TO JOHN W. SMITH, AND ONE-SIXTH TO ROBERT B.

BOONE, OF DURHAM, NORTH CAROLINA.

ELECTRIC CAB SIGNALING SYSTEM.

Specification of Letters Patent.

Patented July 8, 1913.

To all whom it may concern:

Be it known that I, James W. Tn'ru'iu, a citizen of the United States, residing at Angler, in the county of I-larnctt and State of North Carolina, have invented new and useful Improvements in Electric Cab Signaling Systems, of which the following is a specification.

My invention relates to cab signaling systems for railways, and particularly to such systems for steam railroads. While my invention is of the relation specified, however,

it will be readily apparent upon an understanding of it that t e system may be used in other connections, and that one or more of its features may be used in the same or other connections.

In my Patent No. 815,131, March 13, 1906, I have disclosed a signaling system in which use is made of a telephone in a car or cab, and in connection through suitable contacts With conductors which extend along the roadway, one of the conductors, in this patent being the rails, and the other of the conductors being a trolley suitably sup ported along the track. An audible alarm in the form of a bell is included in the circuit between the conductors, but separate from the tele hone in such a manner that when two trains approach within a certain distance of each other, the alarm is sounded by the passage of a current of a certain strength over the circuit. A shunt line in cluding the telephone transmitter and the receiver, and in which there are contacts controlled by the movement of the receiver hook upon the removal .of the receiver, is provided for the par ose of short circuiting or shunting the audible alarm or electric bell when it is desired to transmit messages by the telephone. Normally this shunt line is opened, but upon the removal, of the re ceiver from the hook the shunt line about the bell is closed, and messages may be transmitted without interference from the electric bell.

-The apparatus of the system of my present invention, diifers in several particular features, from the apparatus of my prior atent referred to above. Chief among these differences is the use of an intermittent or pulsatory current for the operation of the warning signals .or alarms for trains running in the same direction. A particular device, and a particularly arranged circuit are provided for the transmitting or sending of this intermittent or pulsatory current to give the warning signal upon the approach of two trains within a dangerous distance of each other. Particular means are also provided for rendering this means for transmitting the intermittent or pulsatory current inoperative, and rendering the tele )hone operative for the transmission of into ligences between trains running in the same direction.

The object of my invention is to produce the simplest system possible for trains running in the same direction which will give etliciont results, and these several features of my invention have been designed and organizedtogether to the procurement of the best possible accomplishment of the objects of my invention.

The contacts which I prefer to use in the embodiment of my invention which I shall describe, are made of substantial proportions, and are operated from a source of power of relatively large size. The contacts may therefore be readily kept clean, and owing to the large power from which they are actuated are not subject to the same troubles as small contacts are subject to under the same conditions. Poor contact and sticking of contacts are most effectually avoided by this provision. In a fourth place sticking of )arts of the a paratus is etlcctually avoided by the use of the intermittent or pulsatory current.

In the accompanying drawings I disclose a specific embodiment of my invention.

Figure 1 is a diagrammatic drawing of my invention, showing two railway cars, or the cabs of two locomotives equipped with the apparatus of the system of my invention, and in which conductors other than the rails of the tracks are used for the transmission of signals; Fig. 2 is a similar diagrammatic drawing in which the rails of the track are used as a part of the circuits of the system; and Fig. 3 is a diagrammatic drawing of the circuits of the standard telephone generally used in telephone practice today.

Referring to the drawing 10, 10 are the rails of a track.

11 and 12 represent two cars or trains at a distance from each other. Each car is equipped with a telephone 13 of the construction shown in Fig. 3. This telephone includes a bell 14 and a transmitter 15, the bell being of the type usually used for calling. It will be noted that the bell is cut out of circuit when the receiver is raised from its hook, and that the transmitter 15 is placed in circuit for talking. Also on each car is a mechanical vibrator 16 consisting of an eccentric 17 on an axle of the car and connecting links 18 and 19 which operate a lever 20 carrying a relatively large contact 21. The lever 20 is pivoted at a central point and is oscillated back and forth by the movement of the eccentric on the axle to make and break contact with a relatively broad cooperating spring contact 22. These contacts 21 and 22 are normally connected in series with the telephone through a source of power 23 between them and the telephone.

Conductors 24and 25 are laid along the track, and are engaged by trolleys 26 and 27 from the telephones, the'arrangcment of the trolleys with respect to the conductors being such that a series circuit is formed from train 11 to train 12 as follows: train 11, telephone 13, source of power 23, con

tacts 22 and 21, trolley 27, conductor 25,

trolley 27 of train 12, contacts 21 and 22,

. trolley 26, conductor 24, trolley 26 of train 11, and back to telephone 13 of train 11. A short circuiting switch is provided in con nection with each air of contacts 21 and 22, and which normally is in the open circuit position shown.

With the system installed as described, the operation is as follows: When. two trains or cars approach within a certain distanceot each other,this distance being determined by the resistance of the line conductors 24 and 25, and the resistance of the apparatus, an intermittent or pulsatory current is sent over the series circuit just described, from the sources of power 23 through the action of the mechanical vibrators 16. The time intervals of the impulses of this current are dependent upon the relative speeds of the two trains, and they may or may not be regular, depending upon those speeds, but they will be of such frequency as to give rapid operation of the warning signal which in this embodiment is the telephone bell. Having received this signal, an engineer or other operator in the-one train may close the short circuit switch 28 on his train and thus short circuit the contacts 21 and 22, with the result'that the vibrator is cut out of circuit and the bell stops ringing, upon the removal of the receiver from the hook. This change of circuit connections and the apparatus in the one train, say .train-11, makes a change in the regularity in the current impulses transmitted through the circuit, inasmuch as only one vibrator is now afl'ecting the circuit, whereas before the change was made, both vibrators were acting. The engineer in the other train therefore knows that the engineer ofan adjacent train wishes to talk to him. He thereforecloses his. switch 28 to short circuit the contacts 21 and 22 of his train, and removes the receiver of his telephone from the hook, whereupon the engineers of the two trams:

- concerning the movements of the two trains,

the receivers may again be placed upon the hooks and the short circuiting switches opened, whereupon the warning signal will continued to sound until one or the other of the trains is.removedfrom the signaling distance of-the other. By the use of this system, which is simple in extreme, and

which is most reliable, collisions. between trains running in the same direction may be avoided. Furthermore the system has the advantage present with most telephone communicating systems between trains or cabs, of furnishing a ready means of communication by which the engineers of the-trains may be accurately informed as to the every movlement of other trains in their section of trac I In Fig. 2 I have shown a modification of previously described, and need not be fur ther commented upon. The mechanical vibrator, however, instead of being actuated 1 from an eccentric on an axle, is actuated b an eccentric on a countershaft 29 in the ca of the locomotive, an eccentric or crank 31 being provided on the shaft for actuating the contacts 21 and 22, and the shaft being.

belted to an axle of the locomotive. It-is to be noted that the belt gearing between the shaft or axle of the locomotive and the shaft 29 is a step-up gearing, such that the shaft 29 is driven at a much higher rate of speed than the axle. This gives a most eificient actuation of the warning signal even at low speeds of the locomotive. Otherwise the system of Fig. 2 is the same as the'system of Fi 1.

an. I have described the best form of my invention now known tome, my invent-ion is capable of many modifications without departing in anywise from its generic s' irit. Likewise one or more of the features Lo my invention may be used in systems of phone receiver-hook switch the same character, or in systems of other characters.- so also some of its features may be changed in some degree without departing from its generic spirit. For instance the pulsating current may not be intermittent and may not be attained by a mechanical vibrator, one or more of the well known electrical vibrators being used. So also 1 may associate the short circuiting switches with the hook of the telephone receiver, as in my prior patent referred to. I desire to cover all such modifications in the annexed claims.

hat I claim is 1. in a signaling device, an electric circuit including a hell, it teletphone, a teleor alternately cutt-ing out the bell and the telephone from the circuit, anexciter in the circuit, a spring contact, a vibrating contact movable toward and from the spring contact and adapted to make and break the circuit, a second telephone, a second vibrating contact, conductors leading from the first telephone and the first vi brnngig contact to the second telephone and second vibrating contact, and a shunt switch located between the telephone and the conductor leading from the vibrating contact and adapted to shunt the exciter and the contacts from the circuit.

2. In a signaling device, and in combination, movable members, conductors station ary relative to the movable members, a circuit upon each member being closed througL said conductors, said circuit including a telephone, a bell, means for alternately cutting said telephone and bell out of the circuit, an exciter, a spring contact, and a pivoted contact adapted for movement toward and from the spring contact, means carried upon each member for engagement with the respective movable contacts for vibrating the same whereby to open and close the circuit of each member, and shunt switches located between the telephones and the movable contacts whereby the exciters and the contacts may be shunted from .the circuit through the stationary conductors.

In testimony whereof I have hereunto set my hand in presence of two subscribing wiitnesses.

JAMES "W. TATUM.

Witnesses J. W. I)UNN'ING, J P. 1)ARRISIL

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