US2480160A - Signaling system - Google Patents

Description

M. C. POYLO SIGNALING SYSTEM Aug. 30, 1949.

2 Sheets-Sheet l Filed June 27, 1945 ug. 30, 1949. M. c. Po-YLo SIGNALING SYSTEM Filed June 27, 1945 2 Sheets-Sheet 2 l, f7/@ggf ATM/FA/EY Patentecl Aug. 30, 1949 lSIGNALING SYSTEM Michel C. Poylo, New York, N. Y., assignor to Federal Telephone and Radio Corporation, New York, N. Y., a corporation of Delaware Application June 27, 1945, Serial No. 601,799

4 Claims.

This invention relates to new and useful improvements in train dispatching systems, and more particularly to a system adapted for combination with a railroad communication system such, for example, as disclosed in the copending application of E. M. Deloraine (37), Serial No. 531,851, filed April 20, 1944.

It is the object of the present invention to devise an arrangement for providing at all times at a dispatchers station and/or on board any train a record of the position and/or speed of one or more trains.

Another object of the invention is to provide means on a moving vehicle, such as a railroad train, to provide a source of signals whereby sub-1 stantially the instantaneous location or the vehicle along a given path may be readily determined or indicated.

The nature of the invention will more clearly appear from the following description of an embodiment thereof, the specific means here disclosed being subject to many variations as will be obvious to those skilled in the art.

In the drawings, Fig. 1 illustrates the general scheme of a railroad communication system with which the dispatchers signaling station is combined;

Fig. 2 illustrates as much of a train radio transmitter as is necessary for an understanding of the invention;

Fig. 3 diagrammatically illustrates a portion of the receiver at the dispatchers station arranged to receive signals from the train transmitters to record the position of the train;

Fig. 4 is a graph of the pulses transmitted from the dispatchers station;

Fig. 5 is a block diagram of the receiver provided on each train to receive signals from the dispatchers station;

Fig. 6 is a curve of the synchronizing or marker pulses sent out from the synchronizing station; and

Fig. 7 is a block diagram of the receiver and transmitter on each train adapted to receive from the synchronizing station and send to the dispatchers station.

In Fig. 1 is shown a dispatchers station 1 from which radio signals may be sent out on carrier frequency f1 via directional antenna 2 and at which radio signals may be received on carrier frequency f2 via directional antenna 3. Preferably the system utilizes an ultra-high frequency or microwave carrier on which intelligence can be transmitted in a plurality of channels by means of time-modulated pulses. As is well known and 2 shown, for example, in British Patent No. 587,941, filed May 26, 1944 and United States Patent No. 2,445,775, the pulses belonging to each channel of' intelligence follow one another, and a group or series of such pulses representing the different successive channels is separated from the next series by a synchronizing or marker pulse having a distinguishing characteristic, e. g., greater width than the width of the intelligence pulses.

Fig. 4 shows a graph of the emission from the dispatchers transmitting station I. In this graph, m designates the marker pulses and a, b, c, d, e, j, the relatively narrow channel pulses. The positions of the channel pulses a-f will be varied with respect to the marker pulse in acu cordance with the modulation impressed thereon.

The modulated carrier can be relayed along the railroad tracks 4, 5 which it is desired to supervise by means of relay stations 6, 'I and `8.

At the other end of the system is a synchronizing station 9 where synchronizing signals may be sent through directional antenna i I superimposed on carrier frequency f2. These serve to segregate the series of channel pulses which may be sent on f2 from station 9 and any one of the trains I5, I and I'I and relayed by means of relay stations I2, I3 and I4 to the dispatchers station l.

The means on each train for receiving and demodulating the signals sent to it from the dispatchers station I may be of any well known design. As indicated in Fig. 5 they may consist of a receiver R adapted to receive signals on frequency f1. This receiver controls a 4pulse width separator and shaper S of known character for example, of the type disclosed in United States Patent Number 2,440,278 which is adapted to be operated by the marker pulses m only. A delay network N of well known type connected with the separator-Shaper S introduces a suiicient time delay between the marker pulse timing and a particular channel timing like channel C, for example, so that the demodulator D, of the type shown in British Patent No. 587,941 or in United States Patent Number 2,199,634 will be conditioned only for action on the desired channel signals, e. g., c which is meant for the particular train on which the receiver is located.

Each of the moving trains, e. g., I5, i6 and Il, is adapted to receive signals belonging to a particular channel on frequencies f1 and f2 and to transmit signals to the dispatchers station on a predetermined channel at frequency f2. The sending is accomplished on a train by means of a transmitter I8 modulated by means of a modulato the modulator I9 shown in Fig. 2 where theY signaling pulse is superimposed on the carrier f2 in its proper phase relation to the marker pulses ml. This signal pulse is modulated from an audio source in a manner to be presently described and shown in greater detail in Fig. 2 andthe modulated signal pulse together with the marker pulse ml are transmitted by the transmitter I8 from the train on carrier frequency f2 towards the dispatchers station I.

In addi-tionl tol modulation by a microphone 23 the transmitter I'B-on a train may be modulated also by' agenerator ZI adapted to generate a 1350"-cycie signalv or a generator 22 adapted to generate a 100f-cycle signal. Both generated signals' being belowv the'range of' audibility, they willnot interfere withspeech transmission on the channel assigned to the-train.

Number23 illustrates a rotatable means e. g., the axleon which a special wheel or a non-drive ing wheel of the locomotive or other car is mounted; Through sui-table coupling 24 the clockwise rotationy of the axle 23 is transmitted to a cam 25 atY a= certain` ratio, and through a suitable coupling' 2S- the' counterclockwise rotation of the axle 23 irs-transmitted to the cam 27. Depending; therefore, whetherv the train goes forward of' backward, the cam 25 will be rotated in a clockwise direction periodically to close a contact 28, or the cam 21 will be rotated in a counterclockwise direction periodicallyV to close a contact 29. Whenever the contact 28 is closed the carrier is modulated by'a 100-cycle and whenever contactZB is closed by a 150-cycle signal and transmitted fromV the train. Thus, for each unit of length the train; travels forward, a 100-cycle signal is sent; and for each unit of length the train travels backwardga 150-cycle signal is sent. Assuming that the circumference of a wheel mounted on aXle` 23' is ten feet and assuming a topspeedof 120 miles'per hour,l or 166 feet per second, one might provide a gear ratio of 8 to 1 to produce two impulses for every sixteen revolutions thatV the` wheel may perform per second, or one impulse every 83d feet. Thus, the position of the train maybe indicated within 100 feet fora speed of" 120' miles per hour, although impulsesA will Ele-sentVv only at the rate of two per secondi Each train? will retransmit on frequency f2 the pulses mi' together withV the signal'pulse properly spacedtherefrom: Thefsignals will -be receivedat the dispatchers station If, on antenna 3 in the usual interlaced channel. pattern as shown for instance inFig. 4- for the-signals that are transinittedzfromthe dispatchers station on frequency f1. Of. course, if no signalv is sent from a train towhich a channel is assigned thenthere will be no, pulse` in its. place The antenna is connectedwitnthe known receiver means 33 adapted to receive and demodulate the time-modulated pulses received.

Number 3I is an audio frequency output transformer on receiver 30 conveying the intelligence received to a loudspeaker 32.' The 100 and 150'- cycle pulses will pass through a low-pass lter 33 to two reeds 34 and 35 connected in parallel with the lter, the reed 34 being tuned to 100 and the reed 35 to 150 cycles. One or the other reed will be caused to vibrate its armature 36 and 3'I, respectively, to alter the magnetic iield of permanent magnets 38 or 39 provided adjacent thereto; The'fimpulses so generated? are rectied and' amplified atL 40 and* 4I^, respectively; to operate stepping mechanisms 42 or 43, as the case may be and are thus accumulatively registered onthecnrresponding stepping mechanisms. Any suitable arrangement may be provided at 42 and 43, e. g., a, pawl and ratchet arrangement of any well-knowntype as for example that shown in Fig. 'Tof Ui Si Patent to Lambot No. 1,072,474, granted September-9, 1913, to cause an indicator or recorder 44 which even may be desired, to movel in one direction or the other in response to each step conveyed thereto from 42 or 43 thus indicating' at any moment theposition of the train.` It' will beseenthereforethat the stepping mechanism willi take onestepl eachtime contact 28T or 29lisf'closedi, theemechanism asin other well known systems notbeing responsive to each cycle of the 10'0 or 150 cycle'- modulation but being responsive to each periodici: su'chm'odulation.

The recorder may' take' anyf one of a number of forms. It may loe-fal counter which displays numerals indica-ting the dist-ance traveled by the train (83 feet for" each" impulseA received in the above-assumed case), or it may consist ofv a Abank. of lampseachof-fwhichis allotted' to a certainl pointr ofthe track and which lamps successively' light, or ofastyluswhich draws a graph on a stripof: paper, etch., and may include some. form' oi speed-indicator.l There willbe one such location recorder end speed indicator at the dispatchersstation' foreach train indicating at all times its exa-ct' position and speed and it should beunderstood that; of course, each channel individually allotted" toa train, is separated from the other channels already in the receiver.

In my reference to` traing it should be understood that this term is used in a broad sense as covering any' vehicle' that" is guided along a given track. It will. also be clear that since instantaneous positioning of several trains are indicatedA substantially' simultaneously by the signals transmitted along, the. track, such provide a good anti-collision signaling system4 between trains.

WhileA I'have referred to station-9 as the source of synchronizing signals, it will be clear that` the synchronizing signals may originate at the dis-V patchers. station IT if desired. It. will be clear that many other variations such as thev details of' the transmitting and" receivingA equipment of. Figs. 2 and 3, andY their combination with other apparatus may loe-made without departing from thel scope ofthe invention. For example, each train could` be equipped with a. receiver for. receiving signals. transmittedY from another train and withV an indicator responsive tothe received signals.

I claim:

1'. In av signaling system, a dispatchers stationprovided with a. receiver to. receive on a carrier frequency signals forming. a plurality of communication. channels, aplurality of trains movable, withfrespect. to saiddispatchers station each.

associated generators to modulate the transmitter on the train once for each unit of distance travelled in one direction, means on each train for connecting the other generator there-at to modulate the transmitter on the train once for each unit of distance travelled in the opposite direction, means at the dispatchers station selectively responsive to the signals transmitted by said generators, and indicator means at said station controlled by the last mentioned means in one sense in response to accumulated signals of one generator and in the opposite sense in response to accumulated signals from the other generator.

2. The signaling system according to claim 1, means for sending from a common point channel synchronizing signals on said carrier, and means on each train to receive and to send out by the associated transmitter said synchronizing signals together with the other signals generated on the train.

3. In a signaling system, a dispatchers station provided with a receiver to receive on a carrier frequency signals forming a plurality of communication channels, a plurality of trains movH able with respect to said dispatchers station each provided with a transmitter to send on said carrier audio signals belonging to a predetermined channel, two different generators of sub-audible frequency signals on each train, means on each train for connecting one of the associated generators to modulate the transmitter on the train once for each unit of distance traveled in one direction, means on each train for connecting the other generator there-at to modulate the transmitter on the train once for each unit of distance traveled in the opposite direction, a low-pass lter connected with the receiver at the dispatchers station, two frequency responsive means connected With the low-pass filter, one tuned to the frequency of one and the other to the frequency of the other of said generators, and a recorder con- 6 A trolled by one responsive means in one sense and the other responsive means in the opposite sense.

4. In a signaling system, a dispatchers station provided with a receiver to receive on a carrier frequency time-modulated pulses belonging to a plurality of communication channels, a plurality of trains movable with respect to said dispatchers station each provided with a transmitter to send on said carrier pulses belonging to a predetermined channel tWo different generators of pulses of a frequency outside of the audible range on each train, means on each train for connecting one of the associated generators to modulate the transmitter on 'the train once for each unit of distance traveled in one direction, means on each train for connecting the other generator there-at to modulate the transmitter on the train once for each unit of distance traveled in the opposite direction, means at the dispatchers station selectively responsive to the signals transmitted by said generators, and an indicator means at said station, the last mentioned means operating in one sense in response to signals from one generator, and in the opposite sense in response to signals from the other generator.

MICHEL C. POYLO.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 253,442 Starr Feb. 7, 1882 1,072,474 Lambot Sept. 9, 1913 1,747,011 Alexanderson Feb. 11, 1930 1,993,497 Wells Mar. 5, 1935 2,089,639 Bedford Aug. 10, 1937 2,311,021 Blumlein Feb. 16, 1943 2,363,416 Henroteau Nov. 21, 1944

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