US1803379A - Telegraphic system - Google Patents

Description

May 5, 1931. w, BUDDE 1,803,379

TELEGRAPHIC SYSTEM Filed Feb. 27, 1928 3 Sheets-Sheet 1 May 5,. 1931.

W. BUDDE TELEGRAPHIC SYSTEM Filed Feb. 27, 1928 5 Sheets-Sheet 2 May 5, 1931. w. BUDDE 1,803,379

TELEGRAPHIC SYSTEM 7 Filed Feb. 27, 1928 3 Sheets-Sheet 5 Patented May 5, 1931 STATE WILHELM BUDDE, or BERLIN-DAHLEM, GER-MANY TELEGRAPHIC SYSTEM Application filed February 2'7, 1928, Serial No. 257,248, and in Germany November 7, 1927.

This invention relates to systems for telegraphic transmission and is more particularly directed to such systems wherein a pinrality of sending and I'GCQlVlllf apparatusarc located at different places and where communication between any two of such stations is to be carried out at will through the medium of an exchange station containing the necessary connecting apparatus, such for 1G instance as is the case with Well-known telephone plants. It isthe tendency in the telegraph art to create a universal standard apparatus similar to the well-known standard telephone setsuitable for any of the receiving apparatus (simplex or multiplex service lines) should be such as to admit of the use ofsuch apparatus.

The requirements to be fulfilled bysuch a standard apparatus, therefore, are among tion as well asto its operation, must be as simple as possible so that any subscriber, public operator in the telegraph office or private subscriber, may be able to readily opdiii'erence in operation whether a private subscriber 1s connected across a multiplex transmission line or whether he is connect d 7 over a line carrying only simplex service. The differences between tle services just mentioned will be referred to later on.

he latter requirement, hitherto, has scarcely been of any importance, because telegraphic transmission in contrast to telephonic transmission has been carried out over fixed wire connections, transmitter, receiver and line being combined to form one fixed unit. Hov ever, the future development obviously will introduce a, change in'that,as is the case in telephony, telegraphic transmission between different stations will be carried out by means of an exchange station equipped with the necessary connecting and switching apparatus. Therefore, it is essential that the subscriber need not'be'inothers that the apparatus, as to its construc-' crate it. Especially, there must not be any printing mechanism.

formed first over whatsort of connection he is to work in order to adjust his apparatus accordingly.

Apparatus best suited for the requirements stated before are in accordance with general opinion, those working according the socalled start-stop principle. An apparatus ofthis type universally known is the teletypewriter of the Morkrum-Kleinschmidt system. Such an apparatus is fulfilling the requirements stated hereinbefore to a very large extent'in that the operator is not required to do anymore difficult work than when operating an ordinary typewriter including the manipulation of keys of an, or-

I dinary key-board. 'lVhen' key is depressed,

the transmitting mechanism sends out at first a starting current impulse and will transmit thereafter the signal corresponding to the depressed key in theform of a combination of five current units into the line. The. system is said, therefore, to work according to the five unit code, each signal beingdivided into five intervals of a complete unit of time, during each of which the current transmitted may be either of a distinct value or zero, or may be either positive or negative. The starting current impulse starts the receiving mechanism at thereceiving station, which picks up the succeeding signal impulses operating the corresponding selectors of the The signal (letter, number, etc.) is printed on a paper sheet or tape, which latter is pasted onto the telegraph form.

This constitutes the fundamental mode of operation. In order to get greater working efficiency it is known totransmit the signals into the line, not directly, as described, but indirectly by means of a perforated tape. In this case, the operation of the key-board would nottransmit the signals directly into the line, but would punch combinations of holes in a perforator tape which would run through a so-called transmitting distributor sending the corresponding signals into the line[ For this purpose, additional apparatus is necessarybesides the ordinary apparatus and must be connected in or out at will by the subscriber according to the conditions required. However, transmission by means of a perforating tape, except in special cases, as in transmission of messages for newspapers. banks, etc.,will only be of advantage when a large traffic is to be handled over the line, or when one message is to be transmitted to several receiving stations simultaneously. :Iowever, the fundamental form of operation is constituted by the direct working of the apparatus into the line without the interposition of a perforator, and for such a system the vital requirement is that such apparatus be for working over any sort of connecting line.

The invention will be more clearly understood by the following detailed disclosure taken with reference to the accompanying drawings, in which:

Figure 1 is a diagram illustrating the principles of multiplex service,

Figure 2 is a similardiagram to that of Figure 1, showing station arrangements,

Figure 3 represents an arrangement to fuliill the requirements of a telegraph when employing a perforating apparatus,

Figure 4 shows one embodiment of apparatus in accordance with the present invention without the use of a perforator apparatus,

Figure 5 represents an improved arrangement of the apparatus according to Figure 4.

Similar reference characters throughout the drawings refer to similar elements. As stated before, the invention, has reference more particularly to multiples: systems employed especially on lines intended to handle a heavy telegraph traffic.

Referring to Figure 1 of the drawings, the fundamental principles of multiple): service may be described as follows. There are several transmitting and receiving apparatus which are to work over the same line L simultaneously, which line, therefore, is referred to as a multiplex line. cloth ends of the n'iultiplex line L are connected each to a distributor or (1 respectively whereby the line and its distributors forms a rigid unit. The brushes 7) and 7), of distributors during each revolution, consecutively connect the multiplex line to different outlets or secondary lines leading each to a separate transmitting or receiving apparatus. This may more readily be seen by Figure 2 of the drawings. According to Figure 2, X and Y are assumed to be main oflices connected with each other by the multiplex line L, A and A as well as B and B are intercommunicating telegraphic apparatus located at the main ofiices X and Y respectively and are connected to the distributors (Z and (Z by leads l9 and 20 respec tively, and 12 and 13, 14 and 15, respectively. 16 and 17 representsecondary lines leading to secondary stations, for instance private subscriber stations C and D and C and D During each revolution of the brushes 7) and Z2 of the distributors (Z and (Z a signal may be transmitted over the line L by each one of the transmitters or may be received by each one of the receivers.

lVith a system according to Figure 2, however, there exists the following drawback: Let it be supposed that a five unit signal is transmitted into the line at a given moment. The signal will arrive at the distributor. First, the starting impulse will arrive and thereafter the live current units will follow in a time rigidly given by the transmitting mechanism. These current units may only be transmitted over the multiplex line during the interval of time during which the brush of the distributor is passing over the sector belonging to the corresponding secondary line. The sequence of transmission of the current units by the distributor therefore, is rigidly determined and generally will be considerably shorter than the sequence of the current units arriving over the secondary line. lVith a direct connection of the secondary line with the distributor, as described, the signal arriving from the secondary line and transferred by the distributor into the main multiplex line L eitl er would not be sent out at all or would be completely distorted. In order to transmit the live current units readily into the multiplex line, a storing up of the signal will be necessary, which, e. may be carried out by a group of live relays acting to store up the signal arriving over the secondary line by means of a secondary distributor whose brushes are started in the well-known manner of the start-stop principle by the starting current impulse.

This is more particularly illustrated by Figure 3. r r r 1"; and r represent the live storage relays intended to check an incoming signal from a secondary line 18 and to transmit it in accordance with the speed of rotation of the distributor (1 of the multi plcX line referred to hereinafter as the main-distributor in contradistinction to the distributor cl, of the secondary line referred to hereinafter as the secondary distributorin due sequence of time. According to Figure 3 18 represents the secondary line coming from an individual station (oliice apparatus or private subscriber) 9', represents the receiving relay, (Z, the secondary distributor set into rotation by a starting magnet wt actuated by the starting current impulse. e represents the main distributor which connects the fi\ storage relays to the multiplex line L consecutively during a fraction'of one complete revolution. thus sending the signal into the line. The remaining part of the surface of the main distributor may be used for transmitting other signals from a different secondary station in the manner just described.

However, the provision of storage relays, as described before, will not be entirely sufficient to overcome all difliculties. As the operator ought not be forced to transmit the signals at definite time periods and, as thereforeprovided no special arrangements are madea signal may arrive from a secondary line at any give time, it is possible that it may arrive at such a time as when the storage relays are partly or wholly in connection with the main line L. The signal stored up thereby would therefore be superimposed upon the incoming signal, the result being the transmission of distorted and unintelligible signals. To overcome this latter drawback the sending out of the signal at the secondary station may be controlled by the distributor located at the main oflice, thus ensuring arrival of the signalseparate from any other signal. This may be obtained by the use of a perforator tape for transmission at the secondary station. The operator, thereby, may depress his keys at'any given moment at will. The depression of a key at first only operates-the perforator, whereby a distinct combination of holes is punched on the perforator tape. The perforator tape is then running through the transmission apparatus and the signals will be sent out into the secondary line by means of the perforated tape in due sequence controlled by the distributor at the main ofiice. This solution of the problem presupposes the provision of a perforator at the secondary station, thus introducing difiiculties and destroying the uniform and equal operation of all apparatus as required at the be ginning. When communicating over multiplex lines, therefore, the'fundamental mode of operation, i. e., a direct working into the line can not be employed. Moreover, the control of the signal transmitted at the secondary station by the distributor especially in the case of lines working in one direction, would introduce difficulties, and the operator at the secondary station would have to execute diflicult adjustments which would require the employment of specially trained personnel. 7

According to my present invention, the operator at the secondary station may be able to transmit a signal directly over the secondary line at any desired time, whereby the apparatus used at the secondary stations may be of exactly the same standard type to be employed as when working over simplex lines. To this end according to my invention, I provide two storage devices at the main office, working in dependance upon each other, as is more particularly represented by Figures 4 and 5.

According to Figure4, (Z, and d represent secondary distributors each (as described with reference to Figure 3) belonging to a storage device 3 and a respectively in the form of five storage relays 1' 73', and r T The armatures of these relays are connected with the segments of the main distributor ring d and thence across the brushes of the main distributor to the main line L (multiplex line The brushes of the distributor (Z and d, repose, when there is no signal being sent over the secondary line 18 upon the segments 6 or 7 respectively, which are provided in addition to the five segments of the five unit system employed.

el is a second main distributor having in the present case of a two channel multiplex system two segments2, 4 and 4, 5, 1, 2 connected as shown in the drawing and described hereinafter.

A start-stop signal arriving from the secondary line 18 over the receiving relay r will be stored up in the well-known manner in the reiay system 8 of the distributor (Z The operation of the apparatus is as follows:

The brushes of main distributors (K and 4,, are supposed to be within the distance 2, 3. Thus, the startin magnet inmay be energized "across the rings of d by the receiving local battery B. The circuit of the starting magnet m is interrupted by the segments 4, 5, 1, 2 of the distributor d,,, which are not bridged over by the distributor brushes. If, under these conditions, a starting impulse arrives from the secondary line 18'followed by thesignal impulses actuating the receiving relay r the starting magnet m of the secondary distributor cl, will be energized and the brushes of the latter put into movement, whereby the signal arriving from the secondary station will be stored up in the relay system '8. The transfer of the stored-up signal into the multiplex line L takes place as follows: The main distributor brushes havingtravelled over the one half 2, 4 of distributor el will now travel over the I otherhalf 4, 5, 1, 2 of the rings of the dis tributors d and ai Thus, at the end within the distance 4, 5 the armatures of the relays of s will be connected successively with the multiplex line L and the current impulses stored up by the relays will be sent into the multiplex line. An exact transfer-will only be secured, if a relay has received a current impulse} from the secondary line before the brush of distributor (Z connects the armature of the relay to the multiplex line. .This the case if the speed of the secondary distributor (Z with respectto the speed of the main-distributor (Z is soadjusted, that one revolution of the secondary distributor corresponds to somewhat less than one half revolution of the main distributor, i. e.,' as much less as corresponds to the time during which the last segment of the distance 1, 2 is swept over by the distributor brush, for, in this latter case, the reception of the last current unit by the last of'the five relays will he finishedin any case before the brush of the main distributor d has reached the last'segment of 1, 2 i. e. before this current impulse lit) may be transferred to the multiplex line L.

Thus, during the time while the segments l, 5, l, 2 are being swept over, the signal stored up by the relay system 8 is sent into the multiplex line, and during the same time, the starting magnet m is in an operable state, the brushes of the main distributor el bridging over the segments 4, 5, 1, 2 and putting in line the magnet m with the receiving battery B. Thus if during this period, a signal should arrive from the secondary line, the secondary distributor (Z will be put into movement and the signal will be stored up by the relay storage system a which will transfer the signal in the following period, while the segments 3, i are being swept over by the brush of the main distributor cZ to the multiplex line L. The storage systems 8 and 8, therefore, alternately checks a signal and transfers it to the main line L. During the time, when s is receiving a signal, .9 is transmitting the preceding signal and vice versa. In the case, however, of a starting impulse arriving at the moment or immediately before the moment, at which the brush of the main-distributor cZ is leaving section 2, 4 and entering section 4, 5, 1, 2 one part of the current of the starting impulse at first will flow through the starting mag net on and the remaining part will flow through the starting magnet m simultaneously. Thus, if the currents are strong enough, both magnets may be energized and operated simultaneously by one and the same starting current impulse.

In order to overcome this undesirable. action switches c and 0' (see Fig. 5) are provided, actuated by the armatures of the relays m and m respectively. The switches e and c are operatively dependent upon each other in such a way that when magnet m is actuated, c is opened by the movement of the armature of m, thus preventing a later actuation of m. If there should be a cessation of signals arriving from the secondary line in a system. as described according to Figure 4, the relays of a and 8 would remain in a position corresponding to the signal last arrived and this signal would continuously be transmitted over the multiplex line. in, order to overcome this d 'awback, according to a further object of my invention as represented by Figure 5, I provide a further main distributor (1,, having segments 8 and 0 so a ranged, that immediately after the relays s and s have transferred the signal stored up to the main line, a circuit is closed across one of these segments and the segments 10 or 11 respectively of further secondary distributors (Z and d bridged over in normal or quiet position by brushes, the circuit thus closed including, furthermore. secondary windings w and w respectively of the relays s and s respectively, whereby the relays are all put into a normal position corresponding to a spacing signal in the receiver. Thus, if within the following revolution of the distributors el (Z d no signal should arrive from the secondary line, this spacing signal will be sent into the main line and no false signal will thus be recorded by the receiver. The main distributor d also serves to bring back the storage relays of 8 and a just after the signal has been taken up by the main distributor el and sent into the line L, thus setting the storage 8 and s adapted to receive a new signal.

The advantage gained by my invention consists primarily in that signals arriving from the secondary line will not only be stored up and retransferred, but signals ar riving in distorted shape will be regenerated completely. A further advantage consist in that a perforating apparatus is dispensed with, so that the signals will be transmitted within the least possible time from the sending to the receiving end, and whereby a di rect communication between the operator at the sending station with the operator at the receiving station is made possible.

lVhat I claim is z 1. An apparatus for the operation of start-stop mechanism in a telegraphic circuit employing a plurality of simple circuits reading from sub-stations to a central station, the same comprising a main rotary distributor, a multiplex service circuit conn cted to the central station across said distributor, and two sets of storage devices for directly transferring signals sent out by the sub-stations to the multiple line through the main distributor, the latter con'lprising successively operating distributor sections for the resp a:- tive sets of storage devices each operative for a distributing action on less than a half revolution of the distributor, wheramy a signal arriving from a sub-station flows only through one storage device, the next signal flows only through the other device. and succeeding signals are then alternately transferred to the one or to the other of said storage devices without overlap, and whereby while the one storage device receives a signal the other will release the previously received signal.

A telegraphic system, comprising, in combination, a plurality of pairs of intercommunicating telegraphic apparatus working acco ding to-the start-stop principle, a common multiplex transmission line, synchronously operated distributors arranged at and having their brushes connected to one end each of said transmission line, individual secondary lines leading from corresponding segments of said distributors to one of a corresponding pair of said intercommunicating apparatus, and two groups of storage relays associated with each of said F condary lines operated by the starting impulse of a signal coming in from the secondary line and adapted for alternately storing up incoming signals and transferring them by way of the associated distributor having diametrically arranged segments connected each with a group of corresponding pairs of storage relays, to said transmission line in due sequence of time.

3. A; telegraphic system, comprising, in combination a plurality of pairs of intercommunicating telegraphic apparatus working according to the start-stop principle, a common multiplex transmission line, synchronously operated main distributors arranged at and having their brushes connected to one end each of said transmission line individual secondary lines leading from corresponding segments of said distributors to one of a corresponding pair of said intercommunicating apparatus, two groups of storage relays associated with each of said secondary lines operated by the starting impulse of a signal coini u g in from the secondary line and adapted for alternately storing up incoming signals, distributor having diametrically arranged segments connected each with a group of corresponding pairs of storage relays for transferring the signals to said transmission line in due sequence of time, and means to restore normal position of said relays immediately after a stored-up signal has been sent out by a distributor.

4. A telegraphic system, comprising, in combination a plurality of pairs of intercommunicating telegraphic apparatus working according to the start-stop principle, a common multiplex transmission line, synchronously operated main distributors arranged and having their brushes connected to one end each of said transmission line, individual secondary lines leading from corresponding segments of said distributors to one of a cor-V responding pair of said intercommunicating apparatus, two groups of storage relays as sociated with each of said secondary lines operated by the starting impulse of a signal coming in from the secondary line and adapted for alternately checking up incoming signals and transferring them by way of the associated distributor having diametrically arranged segments connected each with a group of corresponding pairs of storage relays to said transmission line in due sequence of time, means to restore normal positions of said relays immediately after a stored-up signal has been sent out by the distributor, and a second distributor associated and operated synchronously with each of said main distributors and having segments so arranged as to operate an auxiliary circuit immediately after a signal stored up by a group of storage relays has been sent out by the main distributor whereby the storage relays are restored to normal position to check up a new incomingsignal.

5. A telegraphic system in accordance with claim 3 according to which a secondary distributor having a little less than half the speed of said main distributors is associated with each one of a pair of groups of storage relays and is started by the starting impulse of an incoming signal of the corresponding secondary line, whereas an auxiliary distributor associated and synchronously working with the main distributor is provided which during each half of a revolution alternately puts into line a starting battery with one of said secondary distributors.

6. A telegraphic system in accordance with claim 3, according to which a starting magnet for each relay storage device is provided actuated by the starting impulse of an incoming signal, one of said startingmagnets becoming locked by the other to avoid a simultaneous energization of both.

7. Apparatus of the character set forth in claim 3 wherein the main distributor is provided with means for alternately connecting the storage devices with the substations through secondary distributors and the latter to the multiplex circuit through successively acting segments of the main distributor.

In testimony whereof I have afiixed my \VILHELM BUDDE.

signature.

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