US676936A - Telegraphic code. - Google Patents

Description

lPa'fented june 25, lsol.

c. G. BURKE. yTau-:armani: cons.

(Applclton hd Mar. 29, 1900.)

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UNITED STATES PATENT OFFICE..

CHARLES G. BURKE, OF BROOKLYN, NEW YORK, ASSIGNOR OF ONE-HALE TO JOHN Q. A. WHITTEMORE, OE BOSTON, MASSACHUSETTS.

TELEGRAPHIC CODE,

SPECIFICATION forming part of Letters Patent No. 676,936, dated June 25, 1901. Application tiled March 29, 1900. Serial No. 10,601. (No model.)

To cir/ZZ whom, it nty concern:

Be it known that I, CHARLES G. BURKE, a citizen of the United States, residing at the borough of Brooklyn, in the city of New York,

county of Kings, and State of New York, have invented certain new and useful Improvements in Telegraphic Codes, of which the following is a specification, reference being had to the drawings accompanying and forming Io a part of the same.l

This invention refers to that class or system of telegraphywherein telegraphic signals are sent over a telegraph-line and made to act on a receiving instrument so as to produce a record indicating the deviations of a stylus or siphon in opposite directions from a zero point or line. Heretofore it has been usual in operatinginstruments of this form to designate the deviations from zero in one 2o direction as dots and inthe other direction as dashes and by combinations of these so-formed dots and dashes to indicate the letters 'of the alphabet, numerals, and other desired significations. As all signals representing letters, 85e., under this arrangement have to be composed of these dots and dashes used singly, in multiple, or in combinations, the forming of a `code for the twenty-six letters of the alphabet, the numerals, duc., necessitates the employment of deviations in opposite directions for all of the letters except four and all of the numerals except one. As a consequence Siphon-recorder signals as now made present a zigzag appearance, and the Siphon in producing the record .has to be moved over a considerable space while passing to and from the extreme limit of deviation in one direction to the extreme of deviation in the opposite direction in all such cross 1o combinations. These long movements of the siphon are objectionable because of the ex-v tra time which is involved. Besides, the record becomes more or less illegible and difficult to decipherand necessitates skill for its ,4 5 correct interpretation. In my improvement I avail myself ofthe capability of receiving instruments of the kind described to produce a recognizable dierence in extent of deviation in either direction, as well as their ability 5o to indicate adi'erence in length between succeeding deviations in either direction. Y By this means I command several unit elemental signals, whereas but two are available under present methods. On account of this increased number of elemental units I am enabled to form a code for the letters of the alphabet, numerals, and other desired significations wherein all complete signals may be on one side of thezero point or line, thus avoiding lthe necessity of the siphon crossing 6o zero while forming complete signals or any complete combination of signals. Such a record is clear and uniform in character, easily deciphered, and the signals made more rapidlyand by fewer electric impulses. In practiceI find that eight of these unit-signals give the best general. results, and in this specification I will confine myself to describing how I produce these eight units and how theyare employed in telegraphy, it being under 7o stood that more than eight or less than that number may be produced and used in the same Way. As a basis I select four signals distinguishable from each other by a difterence in their respective lengths-that is to say, by the evidence of the difference in time between successive impulses. For convenience I designate these four elemental unitsignals as signals Nos. 1, 2, 3, and t. Unitsignal No. 1 is produced by sending an elec- 8c tric impulse of a given duration and polarity over the line for the purpose of causing the Siphon to be moved from zero to a certain eX- tent in a direction depending upon the polarity of the impulse. Thereby I indicate the beginning of the signal. After the lapse of one unit of time a second impulse of the same duration and like polarity is sent, and this completes signal No. l. Signal No.2 is produced in the same way, two units of time be- 9o ing permitted to intervene, however, between the impulses. For signals Nos. 3 and 4 three and four units of time, respectively, are made to intervene between their respective initial and iinishing impulses. In addition to these four unit-signal elements diering in length I also employ four other signals distinguishable from them by the effects produced in the recording instrument and in the record by a prolongation of the duration of the impulses Ioo by which theI beginning of signals is indicated. For convenience these additional sighals may be designated as signals plus 1, plus4 2, plus 3, and 'plus 4. To produce plus-sigvpleted by one impulse of .briefer contact. The

effect of this increase in the durationof the initial impulse is to cause a wider deviation from zero than in the case of signal No. 1, so

that although signal plus 1 and signal No. 1 g

agree in length of time elapsing between the initial and finishing impulses they will be distinguishable from -each other` by adierence in the extent of deviation of their initial impulses from the zero-line. Signals plus 2, 3, and 4 differ from signals Nos. 2, 3, and 4 by only a like increase in the extent of deviation of theinitial impulse. In practice I find that an increase of' one-third the ordinary period of the electric contact is quite sufficient to make these differences unmistakable. It is obvious that when these signals follow each other, as would be the case in all combinations of two or more of them, the impulse which is required to define the termination of the time unit or units of the first signal will alsor serve, to indicate the beginningof the time unit or units of the next succeeding signal, and so on to the last signal in the combination, which of course requires a inal impulse. In practice, therefore, it may be said that the transmission and recording of each symbol or signal, except thev last, of a combination of two or more requires but one electric impulse. For example, to transmita combination of signals corresponding to the figures 2314, I send an initial positive impulse over the line, then after two unitsof time a second impulse, thenafter three units of time a third impulse, again after one unit of time a fourth impulse, and

then after four units oftime thev fifth or finalV impulse. A suitably-constructed receiving y apparatus will1 in response to such signals trace marks on the paper or tape, separated from each other by lines of two, three, one, and four units of length, respectively.

While in my system I 4discard entirely the use of the usual signals for indicating letters of the alphabet and numerals, I may, and in practice Ido, assign to the more simple sign'als or combinationsthe letters of the alphabet, numerals, short words in frequent use, punctuation-marks, andthe like, so that my system may be operated entirely independently of any ofthe codes now in use for the transmission of all kinds of messages, and

always with the advantage of increased speed, accuracy, and simplicity.

In transmitting messages each complete combination of signals used for indicating different number or figure rcombinations is separated from adjacent combi-nationsby space-marks longer than thelongest symbol Fig. 4 shows the record ofl groups of signals arranged 'to spell out given words.

In Fig. 1 the zero-line is designated by A, the marks made by the stylus or pen of the recorder when actuated by a primary impulse by B, and those made by an impulse of increased duration by C. The signal for the numeral l will therefore be indicated by 'two of the elemental marks B, separated by one unit of space or time, that for. 2 by two of such marks, separated by two space-units, and so on, whilethenumerals l, 2, 3, and 4 will be similarly indicated by the plus-marks C, which have vgreater de- Viation from the line A. By-selected combinations of these signals, as above explained, I may indicate the letters of the alphabet, the

signals used, preferably, for thi-s purpose being indicated in Figs. 2 and 3.

As I have stated before, the impulses may be on the opposite side of the zero-line from that illustrated.

.The transmission of signals by this means is Very much simplified, and the best condi- 'tions for rapid Working of the line are secured.

1. A telegraphiccode in which the signal elements are distinguished from one another by a difference in length and by their relajtion to a given zero posit-ion, andV in which each group or combination of elements which vrepresents a given letter or character is made u pv of elements having the. same relation.v to such zero position, as set forth.,

2. A telegraphic code in which the signal elements are distinguished from oneanother by a dierence in length and form, andv by their relationto a given zero position, and inwhich each group or combination of elements v which represents-a given letter or character is made up of elements which have the same relation to" such zero position, as-setl forth.

3. A telegraphic code composed of a pl u.

rality of groups off-signal elements, each group representing a given letter or character, and characterized by the relation of its component elements to a given zero position, the several elements of each group .b'eing'disti-nguished bya difference in form corresponding to the strength of the current impulses` producing them, as set forth.

' vCHARLES G. BURKE.

. Witnesses:

M. Lawson DYER, JOHN C; Knien.

IOO

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