US2379865A - Telegraph code converter - Google Patents

Description

y 1945. A. F. CONNERY ET AL 2,379,855

TELEGRAPH CODE CONVERTER Filed May 14, 1943 8 Sheets-Sham I HI &

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L 1 a IlFI M IHII g bv N a! J c: co 8 '1 INVENTORS RLDER F. CONNERY b ja, "09W ATTORNEYS Jul 10, 1945. A. F. CONNERY ETAL 2,379,855

TELEGRAPH CODE CONVERTER Filed May 14, 1943 8 Sheets-Sheet 2 Ps M PS4 PS3 n :5 w #5 INVENTORS RLDER F- CONNERY ERIC R. C- 605 ATTORN EYS July 10, 1945.

A. F. CONNERY ETAL TELEGRAPH CODE CONVERTER Filed May 14, 1943 8 Sheets-Sheet 5 w NJ 0 E E T E N N Q hR E C O V O T mcc m RR OM Rem mm July 10, 1945. A. CONNERY ET AL TELEGRAPH CODE CONVERTER.

Filed May 14, 1943 8 Sheets-Sheet 4 5 52m mezzo:

INVENTORS R'LDER F.QONN ERY 'ERac R. c. COE

ATTGRNEYS July 10, 1945.

A. F. CONNEVRY ETAL TELEGRAPH CODE CONVERTER Filed May 14, 1945 8 Sheets-Sheet 5 Y 3 S m ma EM w 30 C NR. T R $5 M H July 10, 1945. A. F. CONNERY ETAL TELEGRAPH CODE CONVERTER Filed May 14, 1945 8 Sheets-Sheet 6 s m s m: T @N NN R E0. 0 W M w RR A RCYQ E B Pmmd July 10, 1945 2,379,865 renown cons oonvaa'raa Alder F. Connery, Great Neck, N. Y., and Eric B. 6. (Joe, Chatham, N. J., assignors to Postal Telegraph-Cable Company (New York), New York. N. Y., a corporation of New York Application May 14, 1943, Serial No. 486,990

28 Claims.

The present invention relates to automatic printing telegraph systems and particularly to such systems in which transmission is eii'ected by tape transmitters and reception is by printing telegraph mechanism. More particularly still the invention relates to the conversion of the code signals appearing on the perforated tape to code impulses diii'ering from those normally transmitted whereby the signals are eflective to properly operate a receiving printing telegraph mechanism 01' a type diflerent from that normally employed and for control of which the code periorated tape is intended.

A specific example of the system described generally above may serve to define the problem of which the present invention is a solution.

At the present time there is in rather wide use a system of printing telegraphy in which messages are received at a main receiving oiilce on reperiorators (well known in the art), and the perforated tapes thus produced placed in tape transmitters and sent to the subsidiary ofllces where they are received on telegraph printers.

The great majority of printers in such a service are of the tape type, i. e. printers which produce the message as printed characters upon a narrow tape and the originating mechanisms are designed to send signals coded in accordance with the construction of these printers. However, there are instances in which outlying customers of the telegraph company employ'printers of the page type, i. e. printers which produce the messages on an endless web of paper. type of printer is normally constructed in such manner that the code representations for certain characteris differ from the representations oi! the same characters in tape printer operations, it is necessary to convert the code signals transmitted from the tape transmitters to the proper code signals to operate these page printers.

It may be noted here that two tape printers or two page printers may have variations in their construction such that different code representations are necessary to eflect printing of the same character.

In addition to the variations in code representations as between tape and page printers, the page printers require certain signals to initiate the performance oi functions which are not necessary in tape printer operation. For example, page printers must receive signals to initiate operations of line feed and carriage return to which functions there are no corresponding functions of a tape printer.

It is thus obvious that in utilizing both tape Since this and page printers in the same system, it is desirable that the perforated tape received at a main station be utilized without substantial alteration to transmit messages to the branch ofllces whether those omces are supplied with tape or page printers. It is further clear that inorder to do this differing character signals must be converted from one code representation to another and that code signals must be interpolated to cause functional signals to be transmitted to the page printers.

In connection with the conversion of code signals it should be mentioned that two types are necessary arising from the fact that most five unit code signals are representative of two characters depending upon the position of the printer platen at the time of reception. In other words the printer, whether of the tape or page type,

has shift and unshift positions similar to those of a typewriter and the character produced by transmission of any signal and operation of the corresponding type bar depends upon whether the printer is at that moment operating in the upper or lower case.

Our invention solves the problem defined above by providing a secondary transmitter which upon the presence of a signal to be converted or upon certain operation of a monitor printer included in the system to indicate an interpolation, stops the tape transmitter and disconnects it from its associated distributor. The secondary transmitter then advances'to a predetermined position in accordance with the signal in the-tape transmitter or the operation of the monitor printer and is then connected to the distributor, replacing the tape transmitter in this respect, and thereafter the distributor and the secondary transmitter operate step by step to transmit the converted or interpolated signal to the printer at the outlying oflice.

A further problem in systems such as that under consideration is that erasures (commonly called rub-outs) are normally taken care of in a tape printer system by simply tearing out the portion of the printed tape which is erroneous or by gumming a portion of the correct tape over the erroneous portion. When such rub-outs occur and a page printer is used, this method cannot be employed and consequently some means must be provided to assure that there will be clean copies of incoming messages at the receiving office. This is accomplished in our invention by the use of an editingpunch at the main line transmitting, or relaying, ofl'iceand modification of the tape transmitter which, together with control circuits operating upon the modified transmitter, assures the elimination of the unwanted erroneous signals in the tape.

It is an object of the present invention to translate or convert any code differences existing between two printing telegraph codes and to transmit signals in accordance with the translation.

It is another object of the invention to so translate code differences whether the differences involve differences in printer platen position or not.

It is another object of the invention to interpolate carriage return and line feed signals where necessary in order to permit transmission to a page printer from a peforated tape intended for transmission to a tape printer.

It is a further object of the invention to provide for the interpolation of a hyphen whenever a carriage return signal is transmitted in the middle of a word.

It is a still further object of the invention to provide means for deleting a hyphen, which would normally be interpolated upon transmission of a carriage return signal in the middle of a word, whenever the printer is operating in the upper case at this time.

A still further object of the invention is the suppression of erasures and other errors in a message in order to provide a clean copy at the receiving office.

Other objects and features of the invention will appear when the annexed specification is considered in connection with the appended drawings, in which Fi ures 1, 2, 3 and 4 taken together and arranged as shown in Figure 5 form a complete schematic diagram of a preferred embodiment of our invention;

Figure 5 shows the arrangement of Figures 1, 2, 3 and 4;

Figure 6 is an isometric view of the essential portions of a start-stop tape transmitter showing particularly the modifications of the distributor to adapt it to use in connection with the present converter;

Figure 7 is an isometric view of certain contacts mounted upon the frame of a monitor page printer to adapt it to exert control functions in the system of the present invention;

Figure 8 is a fragmentary view of a piece of perforated tape as used in the system showing particularly notches along the upper edge thereof to control the non-printing of erased portions of the message;

Figure 9 is an isometric view of a manually operated punch which is utilized for editing the tape to eliminate erasures; and

Figures 10 and 11 together form a timing diagram for one of the functions performed by the system, namely the conversion of the period signal in the tape printer code to the period signal in the page printer code.

The preferred embodiment of our invention comprises a plurality of relays and rotary switches in combination with a modified start-stop transmitter distributor and a modified monitor page printer. As indicated, both the start-stop transmitter and page printer are of types well known in the art but are slightly modified for the present purpose. The code differences existing as between the tape printer code and the page printer code will, of course, vary for various species of the two printers considered. It will be clear, however, that while the present system is described with reference to a particular set of code changes and code interpolations, the device or system may be readily adapted to other sets of code differences. In the particular set of code differences illustrated it so happens that none of the characters to be translated makes use of the first of the five signal impulses. For this reason certain of the relays have ample time in which to operate and it is unnecessary to provide "complete overlap," If it should become necessary to translate characters including the first signal impulse, a second set of five relays could be interposed between the receiving pulse relays and the distributor segments thereby delaying the transmission of the message by one character. Thus the system as described is not usable when the translations involve the first signal impulse but by the mere addition of a second set of relays this may be accomplished and it is, therefore, to be understood that our invention comprehends such translations.

TRANSMITTER DISTRIBUTOR Referring now to the drawings, Figure 6 illustrates the transmitter distributor of the present system. This transmitter distributor, hereinafter for convenience called distributor, comprises a main shaft 20 driven through the worm 2i and worm wheel 22 and friction clutch plates 23 and 24 by a synchronous or governed motor (not shown). Unless restrained, shaft 20 will rotate at constant speed. Shaft 20 carries a stop cam 25 having on the periphery thereof a projection 26 which may be engaged by one end of stop arm 21. When the stop arm is in the position of Figure 6, it engages the projection 28 and causes the shaft 20 to stop and the clutch to slip. Stop arm 2? is under control of a magnet DM which, when energized, attracts that end of the stop arm remote from lug or projection 28, thereby causing the arm to pivot about point 30 and to disengage from projection 26 and to permit the shaft to rotate. The shaft 20 carries at its upper end a pair of brushes 3! electrically connected together and mounted on the shaft but insulated therefrom by means of the arm 32. These brushes bear on the plain and segmented contact rings 33 and 34, the latter of which comprises seven contact segments 34a through My, 34a being the start signal segment and 349 the stop signal segment, the intervening ones being the signal impulse segments. Shaft 20 also carries thereon a cam 35 which through levers 36 and 31 operates the contact levers 3811 through 38c and the feed lever of a. tape transmitter. This feed lever operates a feed wheel which engages in feed holes 42 and controls feeding of the tape in the usual manner. The contact levers 38a through 38c carry at one end pins 40a through Me which are adapted to engage the signal holes a through 4| e of the perforated tape (see Fig. 8). Levers 38a to 386 carry at the ends remote from pins 40 insulated flexibly mounted contact springs 4311 through 43c which are adapted to make contact with either of the contact bridges 44 and 45, such contact being made through adjustable contact screws 46.

The orientation of brush arm 32, brushes 3| and cam 35 with respect to the lug or projection 26 is such that when the shaft is stopped by stop arm 21, the outer brush 3| is approximately in the middle of the stop segment 34g of segmented contact ring 34; pins 40a through We are lowered out of engagement with the perforated tape and contact springs 43a through 43c are raised andin contact with the contact screws 46 of the upper or spacing contact bridge 45.

The above description refers to a transmitter distributor of a well known type which is modified in the manner set forth immediately below in order to cooperate with the other portions of the instant system.

A lever ll! carries at one end a projection or pin I adapted to engage in notches 4i! (Fig. 8) in the edge of the tape. Lever II! is operated by the above mentioned feed lever in the following manner. When the feed lever makes its downward stroke under compulsion of lever 31, it presses down on lever 35! so as to lower pin if. On the upstroke of the feed lever, pin 1 is per-. mitted to rise unless prevented by the tape. In some instances as will hereinafter appear, an additional lever 38g and pin a (Fig. 2) are provided, the location being such that the pin g is in position to cooperate with notches in the forward edgeof the tape as distinguished from the cooperation of pin M with notches in the rear edge of the tape. Moreover, the pin g is supplied with a shorter horizontal arm than the pin "I, wherefore it is permitted to rise through the tape only after the tape has been advanced one position beyond the code representation with which the notch aligns.

Mounted on shaft 20 are two additional cams I1 and 45 which are adapted to operate each upon a set of contact springs generally designated 50 and II respectively. The set or stack of contacts 50 comprises contact springsila through 50! while the set 5i comprises springs 5 i a through if. The orientation of cams l1 and 48 with respect to the tip of the outer brush ii is such that contacts 500 and 50b open, 500 and 50d open and 50a and 50l'close, when the outer brush 3| has traveled about a quarter of the way along stop segment 34g, that is some degrees before the stop position of the shaft. About 20 degrees after the stop position contacts 50a and 50b close, 500 and 50d close and 50c and 50] open. In a similar manner contacts 5ia and 5ib close, 5ic and Sid close and He and 5i close when the brush 8i has traveled over stop segment 34g, start segment a and to the beginning of the first pulse or selector segment 34b. Contacts 5ia, 5ib, 5ic, 5id, 5ie and Si! open againwhen the brush has traveled about a quarter way along the second selector segment 34c.

In addition to the cams ll, 48 and their contacts, there is added to the transmitter-distributor a magnet TL and two pairs of contact springs 53 and 54, one of which (53) cooperates with the magnet and the other (54) with lever 38!.

The magnet TL when energized acts through armature 55 and plunger 56 upon the transmitter lever 31. By this means lever 31 may be held operated and the transmitter stopped even though shaft 20 may be rotating. As indicated above, a

the contact springs 53a, 53b cooperate with the magnet TL. This is accomplished by disposing the contact set 53 in such manner that when magnet TL is de-energized its armature 55 at the end of the release stroke opens the contacts 53aand 53b. The contact set 54 is so disposed as to cooperate with lever 38f and as long as the projection 40/ is prevented from rising above the .level of the tape, contacts 54a and 541) are maintained in their open position, but as soon as the projection 40,! is permitted to rise either through a notch lif punched in the edge of the tape (Fig. 8) or by reason of there being no tape in the transmitter, contacts 54a and 54b are allowed to close.

Monroe Pumas As has been indicated hereinabove, the monitor printer is a page printer of any of the usual well known types. It is, however, modified by the addition of the control contacts shown in detail in Figure "l. A bracket is mounted on the frame of the printer and carries two sets of contact springs 6i and 82 in a position to cooperate with a shoe II which is fixed to the moving carriage of the printer and," of course, travels with it. The contact shoe 6! and the bracket 50 are relatively so disposed that as the printing nears the end of a line say, for example, 10 letter spaces from the extreme end of its travel, the shoe l3 presses upwardly on contact spring Ila causing If the carriage continues to travel beyond this point, contacts Bio and Bib are held closed by the shoe I and when the carriage comes within a second predetermined distance from the extreme end of its travel, say 2 letter spaces shoe 88 causes contact 82b to break from contact 82a and to make with contact 820 and also causes closure of contacts 62d and 52e.

It should be noted at this point that a letter counter arranged with two sets of contacts successively operable after two predetermined numbers of characters have been registered may be substituted for the monitor printer described above.

SELECTOR RELAYS The selector relays, shown in schematic form in Figures 1 through 4, are electrical relays of usual type and, therefore, their mechanical construction need not be described.

ROTARY SWITCH The rotary switch (Figs. 3 and 4) is of a type which is well known in the art. It comprises a contact bank having a plurality of levels and a wiper for each level, the wipers being mechanically connected but insulated from each other. An operating magnet, by means of a feed pawl, causes the wipers to pass step by step over the contacts of their respective levels. The arrangement is such that when the stepping magnet is energized it withdraws the feed pawl but does not step the switch. Thereafter when the magnet is released the pawl returns to normal position under spring tension causing the switch wipers to step to the next succeeding contacts of all levels.

TAPE EDITING PUNCH As an adjunct to the system there is provided a tape editing punch shown in Figure 9. This punch comprises a body 10 carrying a spring retracted plunger ii, the lower end of which is formed into a punch I2. The body 10 is mounted on a base 13 which has a channel 14 milled therein for guiding the perforated tape. A hole 15 drilled through the base at the edge of the channel 14 serves as a die for punch 12. Pins 16 mounted in the channel 14 cooperate with the feed holes of the perforated tape to hold the tape in correct longitudinal relationship with the punch 12. Thus when the tape is correctly placed in the guide channel 14 and held in proper re ister by the pins 16, depression of the plunger Ii as by striking the upper handle end ll will cause a notch of approximately semi-circular shape to be punched in the rear edge of the tape as shown at ll of Figure 8.

Of course, if the added transmitter pin 40g is to be utilized as has been described above, an

additional editing punch will be supplied to punch this hole.

Cnwmr CONNECTIONS I of a self-interrupting circuit of the stepping magnet of the switch, the distributor to then be restarted and under control of the distributor the rotary switch to be stepped ahead once for each rotation of the distributor, sending out, following each stepping action, a portion of the converted signal or if the signal is one which is transmissible in a single revolution (or character), sending out'during the single rotation of the distributor that converted signal.

The circuit diagram of Figures 1 through 4 is drawn in accordance with the detached contact method of showing relays, that is the relay contacts are not shown associated with their own relay windings but are instead shown as part of the circuit which they control. By this method, the conditions for operation, holding and release of any relay or magnet are clearly shown. As a matter of convenience the contacts are all shown in their non-operated position and all moving springs move downwardly upon operation. Further, all cams shown in Figures 1 through 4 are in the home position, that it are shown in the position which they occupy when the distributor shaft 28 is stopped by the stop arm 2?.

with current over conductor 82 directly from the limiting resistance 9|. The solid ring 88 of the distributor is connected through the keyboard contacts 93 of the monitor printer and the winding of local relay 84 (which controls the magnet oi the monitor printer) and thence through current equalizing resistance 85 to the line 96 and from the line through the winding of the customer's or branch office printer magnet 91 to ground at 88.

When any of the transmitter pins 48 (see Fig. 6) is allowed to rise by virtue of there being a hole in the tape above the pin, the corresponding PS relay is energized. Upon energization this relay closes its make contact thereby connecting signaling battery to the corresponding selecting segment 34b through 34}. Distributor brush 3| sweeps over the segments in turn thus sending the code signal to the distant printer. This operation continues as long as the signal in the tape is to be transmitted directly to the distant printer without conversion, the operation being essentially the same at it would be were the code conversion equipment not provided. In fact, the only difference lies in the interposition of the selector relays PS between the contacts 43 and segments 34.

When typical tape and page printers are utilized the code differences are those set forth below, the remaining character code representations being identical for the tape printers and page printers of the system. In the table below, the minus signs indicate spacing impulses and the plus signs marking impulses.

For the sake of brevity, the contacts of the relays are referred to by means of the relay designation together with a numeral designating the contact number as, for example, contact No. 7 of relay SH will be referred to as SH-L- Selector relays The five transmitter contacts 43a through 43e (Figs. 1 and 6) control five selector relays PSI through PS5 respectively. The energizing circuits for these relays may be traced through local battery 88 (Fig. 1) over conductors 8| and 82 and through separate resistance 83, 84, 85, 88, 81 to the windings of the relays PSi through PS5 and thence through any operated contact, i. e. contact lying on the marking bridge 44 of the transmitter, to conductor 88 and thence through contacts SR4-i I, SR4-i2 and contacts SR63, SRB-l to ground.

Relays PSI through PS5 have make contacts supplying current to the five selector segments 34b through 34} of the transmitter distributor (see Figs. 4 and 6). These circuits extend from signaling battery 90 (Fig. 4) throught limiting resistance BI and thence over contacts SR2-I2, SR2II, contacts SRII2, SR|II to the make contacts of PSI through PS5 and thence over closed ones of these contacts to the segments 34b through 34 of the distributor. The stop segment 34g of the distributor is supplied In the above table wherever shift appears in parentheses, it indicates that inasmuch as both the tape and page printers have to shift into upper case to print the particular character involved, it is unneccessary to perform any conversion with respect to the shift signal which is transmitted in the regular way. The notation is put in simply to make it clear that the particular character is an upper case character. It is, of course, also true that the unshift signal is transmitte in the regular manner to return the receiving printer to its lower case position.

There are instances in which the code for a particular character differs both in the code representation thereof and the case in which the printer is operated. Of course, in these instances the conversion involves the transmission of a shift; signal and an unshift signal as well as the transmission of the signal impulses. An example of this in the above table is the period.

In addition to the translations or conversions set forth above there are certain interpolations which must be provided for. These interpolations occur due to the necessity of sending carriage return and line feed signals in order that the page printer may perform these functions at the end of each line of typing. They are controlled primarily by the contacts GI and 62 mounted upon the monitor printer frame and are modified in accordance with the presence or lack of a space signal on the tape subsequent to the operation oi! contacts BI and prior to the operation or contacts 82. They are also modified whenever the printer is in the shift position at the closure of contacts 62.

For example, it the'signal for a spacing movement or the printer carriage is received alter the closing of contacts 6! then upon that reception the transmission is stopped and a carriage return signal followed by a line feed signal is transmitted from the rotary switch via the distributor segments to the monitor and receiving page printers. It will be seen from the above that upon the termination of a word within the predetermined distance or the line end, say 10 letter spaces, the

' receiving page printer performs its line feed and carriage return functions and the next word starts at the beginning of the ensuing line.

There are cases, however, in which a word does not terminate within the last ten letter spaces oi the line. In this case provision is made so that upon the closure of contacts 62 a succession of signals consisting of shift hyphen unshiit carriage return and line feed is transmitted from the contacts of the rotary switch to the distant printer.

There will, of course, be times when a word does not terminate within the last 10 letter spaces the line and in which the printer is at the time operating in the upper case. When this occurs it is desirable to eliminate the printing of the hyphen inasmuch as it would occur either in the midst of numeral characters or following punctuation marks or one sort or another. For this reason provision is made so that whenever the shift-relay is operated and the space signal is not received in the last ten letter spaces, the

hyphen which would otherwise be sent is deleted and only the carriage return and line nals are transmitted.

In addition to the translations intern-ciations rub-outs or erasures occur and must he provided for. the editing punch described above. When it is desirable that the portion which has been erased should be automatically cancelled from the transmission a hole is punched in the forward edge oi! the tape at the beginning of the portion to be deleted and a hole is punched in the rear edge of the tape at the end of that portion (see a and f Fig. 8). When the first of these semicircular notches in the tape edge arrives at the transmitter it causes suppression of the transmission but permits the tape to be fed through the transmitter. Upon the arrival of the second notch the suppression ceases and normal transmission is resumed.

Frequently it is desirable to have suppression only partially automatic. In this case a notch is punched in the rear edge of the tape both at the beginning and at the end of the portion to be deleted. Upon arrival of the first notch in the transmitter... the transmitter stops and the operator or supervisor incharge of the circuit may then supply, by use or the monitor printer keyboard, substitution for the erasure, if desired. Whether or not this is done the operator may then either cause the transmitter to resume normal operation or cause feeding of the tape with transmission suppressed until the second notch is presented to the sensing pins. Upon the presentation 0! the second notch to the sensing This may be done by the use or pin normal transmission is automatically resumed.

Shift and. stop relays The shift relay SH operates whenever the shirt signal appears in the tape and remains operated until an unshiit signal is sensed by the sensing fingers Mia-c. This relay functions in combination with the stop relays SR1, SR2 and SR3 to determine the particular group of signals to be transmitted from the rotary switch. It also functions in combination with relays PS to determine whether relays SM and SR2 are to be energized alone or together.

Relay SH is energized under control oi the contacts of relays PS! through PS5. The energizing circuit for relay SH may be traced from battery (Fig. 1) over conductors iii and 3?, through resistance 02, winding oi relay SH and thence over contacts PSii-iii, it"), E'S4-itLil,

. PS3--i M2, F52- i PSi-ifiji, thence over conductor W3 and through cam contacts 1153a (controlled by com 49) to ground, the relay ing energized upon the closure oi contact and 5th. As indicated above, relay is, fore, operated upon the closure oi contacts rich e1;-

H and railei contacts PSb--2,i, P8 5 i whenever u a period and causes is necessary to upa period, no. A

alone inasrismittcd in the its indicate... above relay Sm me a period or comma, that the .i'curth impulse only a occurs on the tape. The rising ansmitter pin dud causes operation relay as has been described. The energizing circuit for relay Siti may then be traced from battery 8b (Fig. 1) over conductors 8i and 82 (Figs. 1 and 2) and thence through resistance Hi l (Fig. 2), winding of relay Sm, conductor W5, contacts PSd-i3,ii, Psi-43,, PSE-i hi2, -P$ii,4 to contacts My, 5ie operated by cam 58. Upon closure oi contacts die, Sif ground is supplied to the circuit Just mentioned and relay SRi is energized. The holding circuit for relay SRi extends from the relay winding over its own contacts SRi--2,i and over contacts REP-3,5 to ground, wherefore Sl-ti is held operated until relay RR is operated, as will hereinafter be described.

Relay SR2 is operated whenever a separation sign or a, number (#i sign occurs on the tape. In this connection it should be noted that the separation mark is used to indicate to the started. The separation sign is used primarily to separate the name and the portions or the address and likewise to separate the signature from the body oi the message. Therefore, in converting to page printer operation a line feed and carriage return signal must be interpolated whenever the separation sign appears. 1

Relay SR2 is energized over a circuit which leads from local battery 80 (Fig. 1) over conductors 8| and 82 (Figs. 1 and 2) and thence over resistance I08, through the winding of SR2, thence over conductor III'I, through contacts PS4-I3,I4, PSS-IILIB, PS2-III,I4 (PS2 is operated due to the fact that the code has only its second impulse a marking impulse) PSl-I l,I2, PSI3,4 and contacts III, Me of cam 48 to ground. Thus upon reception of a separation sign, relay SR2 is energized as soon as cam 48 closes its co tacts 5Ie, 5| This relay is held in its operate position by virtue of a holding circuit extending over its contacts SR21,8 and RR3,4 of release relay R to ground and is released upon the operation 01' RR. As state above,

SR2 is also energized upon the reception of a number (it) sign, the circuit in this case extending over the same path just traced for the separation sign, since the code representation for the number sign is the same as that for the separation sign except that it is preceded by a shift signal. Thus. the only diil'erence is that 01' operation of the shift relay SH to alter the pick-up point.

Relays SR! and SR2 are energized together whenever an apostrophe (upper case character, occurs on the tape. Inasmuch as the signal is representative of an upper case character it has, of course, been preceded by a shift signal and, therefore, relay SH has been operated and is still held operated at the time when the apostrophe signal is presented to the transmitter pins. The rising of the third and fourth transmitter pins 400 and d causes operation of relays PS3 and PS4 over circuits already traced. The closure of contacts of these relays sets up energizing circuits for relays SR! and SR2 which may be traced as follows:

(1) From local battery 80 (Fig. 1) over conductors 8i and 82 (Figs. 1 and 2) thence over resistance IM, through the winding oi relay SR! to conductor I05, thence over contacts PS4-8, I, PSfl-d, 3, SH-S, 4, PSI-I3, IE, PSE-Il, I2, PSI-3, 4 and contacts BI Bic 0f.cam 48 to ground, and

(2) From local battery 80 over conductors 8i and 82, resistance I06, winding of relay SR2, conductor IIl'l, contacts PS4--I6, I5, PS3-$, 5 to SH5 and thence over the circuit traced in (l) to ground.

The locking circuits for the two relays are the same as are present when these relays are energized separately and consequently the operation of RR releases both SRI and SR2.

Relay SR3 is energized whenever a "space" signal occurs on the tape provided that contacts H on the monitor printer are at that time closed. SR3 is furthermore energized by closure 01' certain of the contacts 82 on the monitor printer whether or not a space signal is present in the tape. In the first instance, that is when a space signal occurs on the tape and contacts Bl are closed, the energizing circuit for relay SR3 extends from local battery 80 (Fig. 1),

through conductors BI and 82 (Fig. 2) over re-' sistance I08 and the winding of relay SR3, through contacts Mb, 8| a now closed by virtue or the position of shoe 63, and thence over PS4-II, I2, PSI-I9, I8 (PS2 is operated owing to the fact that the code for space has the third impulse a marking impulse), PSI-l3, I4. PSI- II, I2, PSI-3, 4 and contacts Ile, BI! oi. cam- 4| to ground.

In the second instance SR3 is energized over a circuit extending from its winding thence, over conductor IIII, contacts RR-I, 2 and contacts 82d, 62e oi the monitor printer. now closed by virtue of the position of shoe 6! within two letter spaces of the end of the line, to ground. SR3 upon operating closes a holding circuit for itself over contacts SR32, I and contacts RR-8, 4 to ground. Thus whenever a space occurs on the tape after contacts 61 a, Glb have closed, SR! is energized as soon as cam 48 closes its contacts and further if no space occurs then SR! is energized, immediately upon closure of contacts 02d and 62a. Relay SR3 is, of course, released by operation of relay RR.

Relay SR! is effective to stop the distributor and is energized by the rising of the transmitter 6th pin 40 provided, however, that relay SR4 .is not at that time operated. When the tape runs out or if a notch is punched in the rear edge of the tape (e. g. by means of the tape editing punch) the 6th pin 40 is allowed to complete its upward stroke and close its contacts 541: and 54b as described above in connection with Figure 6. The energizing circuit for relay SR5 extends from local battery 80 (Fig. 1) through conductors II and 82, (Figs. 1 and 2), resistance III and thence through winding of relay SR5 and over contacts SR6-8, I, SR4-I3, I4, 54a, 54b .to ground. The relay is locked in its operative position by reason of a circuitextending from its winding over contacts SR68, 'I, SR5-6, 5 and contacts 2, I 0! start key IIII to ground.

Relay SR4 is energized in either one of two ways. One of these is possible only when SR6 has previously been operated and comprises a circuit completed by depressing the non-print tion relay SR4 closes a locking circuit extending over contacts SR4-2, I and contacts SRB-l, 5 to ground.

In the second instance relay SR4 is energized by the rising of transmitter pin 40a which then completes a circuit extending from battery .to the winding of relay SR4 as traced and thence over contacts 59a, 59b associated with sensing pin 40g, 540, 54b to ground. This operation of SR4 is independent of the operation or SR5. The

- energization of relay SR4 in either event serves to disable all of the PS relays and to thus suppress transmission, this being accomplished by removing, at contacts SR4I I, I2 (Fig. 1), ground from the marking bridge 44 oi the transmitter.

Relay SR8 is energized whenever relay SR4 has been energized and the sensing pin 40! rises through a notch in the edge of the tape. The energizing circuit for this relay extends from local battery over conductors 'II and I! through resistance 3, winding of relay SRl, contacts SR-IB, I4, contacts 54a, 84b to ground. Since the 6th pin 40) rises at about the same time as cam 41 permits contacts 50a, 50b to close. the holding circuit for SR6 is closed at about the same time that the relay is energized and is mainasvases tained closed for nearly a complete revolution of shaft 28 and then opens releasing SR8 just prior to the time at which brush 8| comes to rest on stop segment 84!.

It connection with the operation of relays SR4, SR5, SR8, ltshould be noted, as has been explained above, that the transmitter pin 400 which under certain circumstances controls relay SR4 is arranged to operate subsequently to the pin 48] which controls relay SR5. Consequently when the tape runs out relay SR is operated stopping the transmitter, and thus, of course, preventing the operation of relay SR4.

Transmitter start magnet As has been described hereinabove, the transmitter start magnet DM when operated removes the stop arm 21 from the path of the projection 28 on cam thereby permitting the distributor shaft 20 to rotate. The magnet DM is normally energized and, therefore, the shaft 28 permitted to rotate continuously. The energizing circuit extends from local battery 80 (Fig. 1) over conductors 8l' and 82 (Figs. 1, 2 and 3), thence over resistance II4 (Fig. 3) to the winding of magnet DM, thence over contacts 2 and I of the tape lever I Hi (the auto stop lever which is well known in the art) contacts PR-I,2, SEE-L2, SR8II,I2, SR2I,2, SRI-I3, to ground. The circuit just described may, of course, be broken by operation of any of the relays PR, SR5, SR8, SR2, or SRI.

Although it was stated above that this circuit might be broken by operation of relay PR, this does not happen-in practice inasmuch as relay PR operates only after the operation of SR5, SR8, SR2, or SRI. Consequently, PR is effective only to hold the circuit open after it has been opened by operation of the relays SRI, SR2, SR8 or SR5. Also after being broken at the contacts of relays SRI, SR2, SR3 or SR5 the circuit to transmitter magnet DM may be closed by the operation of relay SR4 as has been described above in connection with that relay. Further, after'being broken in the manner described above the circuit may be closed and broken repeatedly by operation of rotary switch magnet RS provided relay HR has been operated, the means for so making and breaking the circuit extending from contacts PR,I,2 over contacts I-IR-4,3 and contacts RSI,2 to ground. In brief, magnet DM may be released, stopping the distributor, by operation of any of the relays SRI, SR2, SR3 or SR5. It may be re-energized by operation of SR4 or it may be repeatedly energized and released by operation of rotary switch magnet RS.

Transmitter lock magnet TL 4 over contacts HR8,| to ground. It is clear that this magnet isenergized by the operation of relay HR and released by the release thereof.

Rotary switch magnet RS This magnet is normally not operated. It is, however, provided with two energizing circuits,

3)'resistance III (Fig. 3) through the winding 1 oi magnet RS, thence over the self interrupting contacts RS--4,2 and over parallel contacts SRI- 3.4, SR2--l8,ll, SR3I3,I4, and over contacts HR-II,I2 and contacts 50c and 50! controlled by cam 41, to ground. The circuit Just described is completed by the closure of contacts 50c and f at the end of a revolution of the brush shaft provided that one of the relays SRI, SR2, SR3 has been previously operated. When magnet RS is energized .through this circuit it operates, withdrawing the feed pawl and opening its selfinterrupting contacts RSII,8.

The opening of the contacts breaks the circuit, releasing magnet RS and also releasing the feed pawl thereby causing the switch to be stepped to the next point under spring tension as previously described. At the same time that the switch is stepped to its new position contacts RS-8,4 close restoring the energizing circuit of the magnet which thereupon repeats its operation and continues to step from point to point until finally the circuit is broken by the operation of relay HR, as will be described hereinafter.

The second of the two energizing circuits for magnet RS extends to the winding in the same manner as described above and thence over ,conductor I20, contacts HR'--8,5 and contacts 5011, 500 of cam 41 to ground. This circuit is completed upon the closure of contacts 50d; and 500 subsequent to the operation of relay HR. At the time of the closure the distributor shaft 20 is in motion.

The circuit is broken by opening of the contacts 50d and 50c at approximately 15 degre s after the shaft passes the home position, that is the position in which it would be stopped were magnet DM de-energized. This circuit continues to be made and broken as long as the shaft rotates until it is finally broken by the release of holding relay HR.

Holding and release relays HR, PR and RR The energizing circuits for relays HR, PR and RR (Fig. 3) are connected to the contacts of control level VI of rotary switch RS. Certain of the contacts points of this level, namely those designated I, 5, 8, II, I5, I9 and 22 are the pickup points for which magnet RS hunts when energized through its self-interrupting contacts RS-4,3. These pickup points are selected in accordance with the operation of relays SH. SRI, SR2 and SR3 together with the operation of contacts 52 of the monitor printer, all of these contacts being effective either singly or in combination with others mentioned. The various pickup pionts are thus identified with the signal to be transmitted whether such transmission is of an interpolated signal or of a converted signal.

When HR is energized it breaks, at contacts HR-I I, I2, the self-interrupting circuit to magnet RS and places the latter under control of cam 41 through the medium of contacts 50d and 50c which are in a circuit previously described. The various energizing circuits for HR may be traced as follows:

(1) When SRI is alone operated the energiz ing circuit for HR extends from battery through conductors 8|, 82 (Figs. 1, 2 and 3) thence over resistance I2I (Fig. 3), winding of HR, conductor I22, contacts SRI-I8, I1, conductor I23, contacts SR2-I4, II, conductor I24,

contacts SHI6, I4, conductor I26 to contact point 22 of level VI of the rotary switch, and thence over the wiper I26 that level to ground. It is clear that this circuit is completed and HR operated only when the wiper I26 has hunted for and found contact 22 of level VI. Contact 22 of the level VI is identified with the transmission or a period.

(2) When SRI and SH operate together the circuit extends as in (1) above to SHI 6 and proceeds thence over SHI6 and conductor I21 to contact point I6 of level VI, and thence over wiper arm I26 to ground. The contact point I6 01' level VI is identified with the transmission of a comma.

(3) SRI and SR2 operated. In this case the circuit extends as in (1) above to SR2-I 4, thence to SR2-I6 and over conductor I26 to contact of level VI and thence over wiper I26 to ground. Contact point 6 is identified with the transmission 01' an apostrophe.

(4) SR2 alone operated. In this case, the circuit extends from the winding of relay HR over conductor I22, contacts SRI-I6, I6, contacts SR2-4, 6, conductor I33, contacts SH--I2, II, conductor III to contact II and also to contact I of level VI of the rotary switch and thence over wiper I26 to ground. Contact points I and II are identified with the transmission of carriage return and line feed signals, the only purpose in supplying two contacts being to lessen the time spent by the rotary switch in hunting for pickup points. The contact is duplicated with respect to the carriage return and line feed signals because these are frequently recurring.

(5) SR2 and SH operated. The circuit in this instance proceeds as in (4) above to SHI2, thence to SHI3 and over conductor I32 to contact point III of level VI oi the rotary switch and over wiper I26 to ground. This contact point is identified with the number sign.

(6) SR3 alone operated with the carriage not at the end of a line but within the prescribed number of spaces from the end so that contacts 6| of the monitor printer are closed. In this case the circuit proceeds as in (4) above to SR2-4, thence over SR2-3, SR3II, I6, conductor I33, contacts 62b and 62a, conductor I34, conductor I35 and conductor I3I to points I and II of contact level VI of the rotary switch and thence over wiper I26'to ground. Contacts I and II are, as has been above stated, identified with the transmission of carriage return and line feed signals.

(7) SR3 operated at a time when the carriage of the monitor printer is at the end of a line and consequently contacts 62b and 620 are closed by virtue of the pressure exerted upon contact 621) by shoe 63. In this case the circuit proceeds as in (6) above to contact 62b and thence over contact 62c, contacts SH2, I and conductor I36 to contact point 8 of level VI and thence over wiper I26 to ground. Contact point 3 is identified with the transmission of signals for hyphen, carriage return and line feed.

(8) SR3 and SH operated at a time when the carriage is at the end of the line and consequently contacts 82b, 620 are closed. In this case the circuit extends as described in (7) above to contact SH2, thence to contact SH3 and over conductors I35 and I3I to contact points II and I which, as has been stated hereinabove, are identifled with carriage return and line feed signal transmission.

Irrespective of how operated, HR closes its holding circuit over its own contacts HR-Z,

HR-I and over parallel make contacts SRI-l, I, SR2-3, 3 or SR3-3, 4 to ground. Thus relay HR is operated whenever the wiper arm I26 of the rotary switch reaches a selected one of the pickup points or contacts and is held operated by any one of the relays BRI, SR2 or SR3, and is released when these relays are released.

Relay PR The energizing circuit for pre-release relay PR extends from local battery 30, over conductors II and 32, through resistance I43 (Fig. 3), thence through the winding of relay PR over contacts HR-I4, I3 to conductor MI and thence over contacts Ho and Old (when closed by the operation 01' cam 43) and over conductor I42 to contact points 3, 6, I3, I6, 26 and 24 or level VI of the rotary switch. Therefore, relay PR is energized by the closure of contacts BIe and 6Id at any time when relay HR has been operated and wiper arm I26 has reached any one or the contacts 01' level VI above mentioned. It should be noted that prerelease contact 3 is associated with pickup contact I, pre-release contact 6 is associated with pickup contact 6, pre-release contact I3 is associated with pickup contacts 6 and II, pre-release concontact 24 with pickup contact 22.

Upon operation PR closes its holding circuit over its own contacts PR4, 3 and over contacts 53b and 53a associated with armature 66 of transmitter lock magnet TL and thence to ground. It will be recalled that magnet TL is energized by the operation of relay HR. Contacts 63a and 63b of magnet TL are adjusted to open only when the armature 56 of the magnet TL has reached the end of its release stroke, and therefore, PR is held operated as long as magnet TL is operated and in fact until the magnet has completely unlocked the transmitter.

Relay RR The energizing circuit for release relay RR extends from local battery 60 through conductors 6|, 82, thence over resistance I43, through the winding of RR, and thence over HR-l3, I6 and conductor I44 to contact points 4, I, I4, Il, 2|, 26 which are the release points and each one 01' which is associated with the pre-release point mentioned above, which has the consecutive lower number. Therefore, relay RR is energized as soon as the wiper arm I26 reaches any one of the contact points of level VI above mentioned. provided only that relay HR has already been operated. A locking circuit for relay RR extends over its own contacts RR-I, I and thence over contacts 63b, 63a operated by armature 66 of transmitter lock magnet TL to ground. Therefore, relay RR is released together with relay PR upon the complete unlocking of the transmitter.

Line circuits of the rotary switch The wiper arms of levels -I, II, III, IV and V of the rotary switch designated respectively I46, I46, I41, I48 and I49 are connected respectively to the selector segments 34b, 34c, 34d, 34c and 34f of the distributor. The contacts of the levels I, II, III, IV and V are so wired as to send out the required signal combinations through the distributor segments. Thus when the wipers stand on their respective No. 1 contact points, only level IV has a contact connected to the common battery lead which lead extends from line battery 36 through resistance 3| and over conductor Ill,

a,s7a,aoo 9 contacts Hit-ll, II, conductor Ill to all the (Fig. 3) thereby causing shaft II to stop upon switch contacts of the levels 1', II. III, IV and V the completion of itsrevolution. ln'additlon the which are utilised in the tr of signals. operated SR relay prepares an energizing circuit Thus when the switch stands at the No. 1 posifor relay HR. by connecting the winding 1 that tiomthatiswiththewimrsontheNo. 1 contact points of their respective levels, a No. 4 marking only is transmitted to the line, this being the page printer code signal for carriage return.

when thewipers rest on contact points 2 of levels I through V only in level II is there a contact point which is connected to the common battery lead ill. Consequently at this time a s al having a second impulse marking is transmitted, this'being the page printer code for line feed.

' Other combinations transmitted when the switch wipers rest on other contactpoints may be traced fromthediagramanditwiilbeclear thatthe sequence of signals transmitted is in accordance with the conversion or interpolation required by the code variations and is under control of the perforated tape. It should be noted that since the-rotary switch always stops on arelease point there is no connection between distributor segments when the switch is idle.

Oran-non Before explaining in detail the mode of operating in connection with an illustrative example thereof, there is given in the following a general outline of the various operations.

Preliminary when current is first supplied to the device the only circuit completed is that to the distributor magnet DM which immediately operates and per- During the greater part of the transmission no translations are made-and no signals interpolated. This may be termed normal operation. After placing a tape in the transmitter the operator presses the start key llii (Fig. 2). This breaks the holding circuit of relay SR5, releasing itand causing energization of DM. Magnet DM again frees the shaft '20 which commences to rotate, operating the transmitter and distributor brushes.

Pins a to e rise through holes in the tape causing energization of their respective PS relays. The PS relays in turn connect signaling battery II to segments b through I and as the brush ll sweeps over the segments in turn the desired characters are sent to the line and cause operation of both the monitor and distant printers.

Translation When acharacter requiring translation is presented to pins 40 the appropriate PS relays are energized setting up the correct circuit for energization of SRI or SR2, or both. Closure of con- .tacts lit, Ile completes the circuit energizing one a relay is operated the circuit to DM is opened relay to the appropriate pickup point on the control level VI of the rotary switch (Fig. 3). The determination of this pickup point is likewise under thecontrol of relay SH as has been explained. The SR relay also prepares a locking circuit for relay HR and in addition completes a circuit for energizing the rotary switch magnet RS through its self-interrupting contacts. RS then repeatedly operates and releases in rapid succession stepping the wipers of the various levels of the switch from contact point to contact point until the wiper of the control level IV arrives at the particular pickup point to which the winding of relay HR is then connected.

, At this time relay HR operates and locks. This relay performs the following functions:

(1) Breaks the self-interrupting circuit to RS, stopping the hunting of the rotary switch;

(2) Connects the windingof RS to cam contacts "d, "c (Fig. 3) and at the same time connects the winding of DM to break contacts RS-l 2, thus interlocking the rotary switch and the distributor shaft so that they control each other;

(3) Connects signaling battery to the wire iii leading to the contact points of selector levels I through IV of the rotary switch;

(4) Energizes magnet TL, thereby locking the transmitter to prevent feeding of the tape;

(5) Connects the winding of RR to the release points and sets up a connection between the winding of PR and the pre-release points, which connection will be completed at the proper time by closure of cam contacts Sic, ild.

Magnet DM, energized over contacts RS-i, 2 allows the distributor shaft to rotate sending to line the character present in the selector levels I through V at the particular pickup point selected. The rotation of the shaft closescontaets "d, We, thereby energizing rotary switch magnet RS. The operation of RS releases DM causing the shaft 20 to stop at the end of the revolution.

Near the end of the revolution contacts d, 50c again open, releasing RS and causing the stepping of the switch to the next following contact points. Release of RS also re-energizes DM, causing the shaft to rotate and the brush to send out the character present at the next point of levels I through V of a switch This alternate operation of RS and DM continues until the prerelease point is reached and the brush 3| commences to send out the last character from the switch. As the shaft rotates at this time contacts Bic, Sid close, thereby-energizing pre-release relay PR.

PR operates and locks and as a result holds open the energizing circuit to DM preventing reenergization of that magnet. Near the end of the revolution RS is released stepping the switch to the release point and immediately energizing release relay RR. RR releases relay SRI or SR2 which restores the signaling battery connection to the distributor over the PS relay contacts. Also restores the normal energizing circuit to DM and normal transmission is resumed.

Interpolation Normally carriage return and line feed signals will be interpolated at the first letter space after printer contacts 6| have been closed by shoe 63 (Figs. 2 and 7). Closure of contacts 6| prepares an energizing circuit for SR3. When a space character is presented to the transmitter pins 40a through 40c, PS3 alone is operated completing the circuit to SR3. If no space occurs after contact 6| is closed then the energization of SR3 is under the control of contacts 62d and 62a. From this point forward the action is similar to that described above for the energization of SRI or SR2, carriage return and line feed signals being sent to the line from the appropriate contact points of the switch levels I through V, these signals being accompanied by a hyphen or not, as has previously been described.

Correction of errors Before placing a tape in the transmitter the operator scans it for errors, mutilations, etc. Where any error occurs which is to be deleted from the printed copy, the operator by means of the editing punch, notches the tape before and after the error. If the system is provided with the additional transmitter control pin 40g which has been hereinabove described the operator may make the first notch in the forward edge and the second one in the rear edge of the tape. If not so provided both notches may be in the rear edge of the tape. When the tape is placed in the transmitter, transmission proceeds as above described either normally or with translations and interpolations until the first notch is presented either to pin 40f or to pin 40g.

If the first notch is in position to cooperate with pin 40) this pin rises through the notch causing closure of contacts 54a and 54b and energization of relay SR5. SR thereupon operates and locks, preparing an energizing circuit for relay SR4 and also opens the energizing circuit to distributor magnet DM, causing shaft 20 to stop at the end of the revolution, that is after transmission of the character in line with which the notch was placed. If any characters are to be substituted for the erroneous ones the operator types them manually on the keyboard of the monitor printer and then presses the non-print key I00. If no characters are to be substituted the operator presses the non-print key at once.

The non-print key completes the energizing circuit to relay SR4 which operates and locks. In operating relay SR4 breaks the common energizing circuit to the PS relays, so that although tape may be passed through the transmitter no signals will be sent out to line.

If the first notch in the tape was in position to cooperate with pin 40g SR4 would have been directly energized by this pin rising into the notch, although this energization would have occurred upon the signal following the one in alignment with the notch this being due to the shortened horizontal arm of this pin as previously described.

No matter how operated relay SR4 completes an energizing circuit to DM, releasing the shaft 20 and allowing the transmitter to feed tape. Tape therefore passes through the transmitter but without sending out signals. Upon presentation of the second notch in the tape to pin 40! this pin rises and owing to the prior operation of relay SR4 causes, by means of associated contacts 54, a

completion of an energizing circuit to relay SR6. Relay SR5 then operates and locks over cam contacts 50a, 50b now closed because the shaft 20 is in motion. SR8 breaks the common energizin circuit to the PS relays which, however, is already broken by SR4, thus ensuring that the character over which the second notch was placed shall not be transmitted. Operation of relay SR6 also releases SR4 and SR5. SR4 breaks the energizing circuit to magnet DM but this circuit is immediately restored by the release of SR5. Near the end of the revolution contacts 50a, 5012 open, thereby releasing SR8 and restoring the conditions to those of normal transmission.

ILLUSTRATIVE OPERATION As an example of the operation of the device, the translation of a period from the tape printer code to the page printer code will be described in detail. In the tape printer code the period is represented by a marking impulse in the No. 4 position only and is in the lower case, that is the printer is unshifted at the time this occurs. In the page printer code the period is an upper case symbol and the code, comprises a shift signal followed by a signal composed of marking impulses in the third, fourth and fifth positions followed by an unshift signal. In the following discussion the operations are given in chronological order and are represented also by the timing diagram of Figures 10 and 11. For the purposes of this example, it will be assumed that the distributor shaft 20 is in motion, that the brush 3| has just completed transmission of a letter and has started to pass over the stop segment 34g and that a period, i. e. a code representation comprising a hole in the No. 4 position of the tape, is over transmitter pin 40d:

(1) Brush 3| passes the home position about the middle of the stop segment 34g,

(2) The 4th transmitter pin 40d rises and causes energization of relay PS4,

(3) The brush 3| passes to the start segment 34a opening the line and sending a start signal to the monitor page printer as well as to the distant page printer,

(4) Relay PS4 connects signaling battery to the 4th selector segment34e. Other segments are at this time disconnected. Also at this time PS4 sets up at its contacts PS45, 6 the combination for energizing relay SRI. This circuit is, however, not completed at this moment.

(5) Brush 3i reaches the beginning of the first selector segment 341). At this time, as may be seen under 5 (Fig. 10) contacts 5Ie, 5 close under control of their cam 48 completing the energizing circuit for relay SRI ( cams 41 and 48 operate their contacts at every revolution of the shaft 20 but are eifective only when the appropriate circuits are set up).

(6) SRI disconnects, at contacts SRI-4|, I! the signaling or line battery 90 from any of the selector segments 34b through 34f that have been batteried, in this instance only segment 34c. SRI also breaks the energizing circuit to magnet DM, this break occurring at contacts SRI-l3, l4.

(7) SRI closes its holding circuit at contacts SRI-4, 2. Also SRI prepares an energizing circuit for magnet RS at its contacts SRI3, 4 this circuit to be completed later, and, in addition, SRI connects the winding of relay HR to contact 22 of level VI of the rotary switch, that is to the pickup point associated with the transmission of a period.

(8) Brush 3| passes on to the second selector segment 34c.

(9) Cam 4. opens contacts lie and II! breaking the energizing circuit to relay SRI but without effect since SRI isnow held operated as indicated in ('1) above.

(10) Brush 3| sweeps over the remaining selector segments 340 through 34!. Since all selector segments are disconnected from battery, a blank is sent to the line, that is the unwanted No. 4 imulse is suppressed. This blank signal, comprising five intervals of line open condition, causes the monitor page printer and the distant page printer each to go through an idle cycle.

(ll) Brush ll passes to stop segment 34a closim the line.

(12) The 4th transmitter pin 44d withdraws releasing relay PS4.

(13) Cam 4l closes contacts Ne and It! completing an energizing circuit to magnet RS over the self-interrupting contact Its-3,4.

(l4) Shaft 28 and brush 3| come to rest in the home position, that is about the center of segment 34a, stopped by the release of magnet DM, as

. mentioned under (6) above.

(15) Magnet RS operates, withdrawing the feed pawl of the rotary switch. In operating, magnet RS opens its own energizing circuit and, therefore, immediately releases, stepping wipers I26 and I4! through I49 ahead on the release stroke. Inasmuch as the distributor brush Si is at rest on Y the stop segment 349, no signal is sent out from the switch at this stage. The release of the armature of magnet RS recloses the energizing circuit and the alternate operation and release of magnet RB continues stepping the wipers as many steps as are necessary until (16) Magnet RS steps the wipers I26 and I4!) through I49 to the period pickup point identified by contact 22 of level VI at which time the energizing circuit to HR, which was set up as indicated in (7) above, is completed by wiper I23.

(17) HR breaks, at its contacts I-IR-l l,l2, the

self-interrupting circuit to magnet RS leaving that magnet in its released position.

(18) The holding circuit for relay HR is completed over its own contacts and contacts sRl-i and SRI8. HR also causes energization of magnet TL due to closure of its contacts HRI,8. Furthermore, HR prepares, at its contacts HR- l2,l4, an energizing circuit for PR which, however, is not yet completed. In addition, HR, at its contacts HR-l 5, l 6- connects the winding of relay RR to all release points of level VI of the rotary switch (namely points 4, I, I4, ll, 2|, 25 of this level). In addition, HR, at contacts HR-ILlli connects signaling or line battery 90 to certain contacts of the selector levels I through V of the rotary switch. Furthermore HR prepares at its contacts Hit-5,6 the second energizing circuit for magnet RS which, however, is not yet completed. HR also completes the energizing circuit i'or distributor magnet DM, this completion occurring at contacts HR3,4 and the circuit extending over contacts RS-l ,2.

(19) Magnet DM operates releasing distributor shaft 20.

(20) Distributor shaft 2|) commences to rotate.

(21) Magnet TL holds down the transmitter pins and feed pawl preventing feeding of the tape and energization of any of the PS relays. Cam 41 opens contacts We and 50!, cam 41 also closes contacts 500 and 58d thereby energizing magnet (22) Brush 3| passes on to the start segment 34o opening the line and sending a start signal to the distant printer as well as to the monitor age printer.

(23) Magnet RS operates releasing magnet DM and withdrawing the feed pawl of the rotary switch.

(24) Brush 3| passes over the live selector segments 34b through 34! sending to line the shift signal as set up on contacts 22 of levels I through V of the rotary switch. This shift signal is indicated in the timing diagram (Figs. 10 and 11) and comprises marking impulses transmitted during the 1st. 2nd, 4th and 5th impulse intervals of the five unit code. Following this the brush passes on to stop segment 34g (Fig. 11) closing the line.

(25) Cam 4! opens contacts We and d releasing magnet RS.

(26) Bh'aft 2|) comes to rest with brush ll at about the center of segment 340, this stopping being caused by the release of magnet DM.

(27) Release of magnet RS steps the rotary switch wipers to contacts 23 of the various levels and re-energizes magnet DM. 7

(28) Magnet DM releases the distributor shaft.

(29) through (37) These-steps are identical with (20) through (28) respectively except that at time 33 a signal comprising 3rd, 4th and 5th marking impulses is sent to the line over contacts 23 of levels I through V of the rotary switch and at time 36 the rotary switch steps its wipers to contacts 24 of the various levels.

(38) Shaft 29 commences to rotate in the same manner as was described in (2'0) above.

(39) Cam 4'I closes contacts 500 and 50d thereby energizing the switch magnet RS.

(40) Brush 9| passes on to the start segment 3411 opening the line.

(41) Magnet RS operates releasing magnet DM and withdrawing the feed pawl of-the rotary switch. v

(42) Brush 3| passes to the first selector segment 34bcommencing transmission of the unshift signal as set up on contacts 24 of levels I through V of the rotary switch. Cam 48 closes contacts Sic and Bid energizing relay PR. (Note that the energizing circuit for this relay was prepared when relay HR operated as described in (18) above.)

(43) Contacts PRI,2 of relay PR open the energizing circuit to magnet DM preventing reenergization of that magnet when magnet RS releases as described under (49) below.

(44) PR closes its holding circuit extending over contacts 53a and 53b of transmitter lock magnet TL. v

(45) Cam 48 opens contacts tile and Sid breaking the energizing circuit to PR which, however, is now held operated over its holding circuit.

(46) Brush 3i completes the transmission of the unshift signal (indicated in Fig. 11 between time points 42 and 48 and comprising five units of marking impulses). The brush passes on to the stop segment 34g closing the line.

(4'?) Cam 4! opens contacts 50c and 50d releasing magnet RS.

(48) Shaft 20 comes to rest due to release of magnet DM. Brush 3i now stands at approximately the center of stop segment 34g.

(49) Release of magnet RS steps the rotary switch wipers to contacts 25 and relay RR is energized.

(50) RR at its contacts RR-3, 4 breaks the holding circuit of SRl which is thereupon re-' leased.

(51) RR closes its holding circuit over contacts 53a and 63b of magnet TL. SRI opens contacts SRl-S, 6 and thereby releases HR. Also SRI at contacts SR|--l6, l1 breaks the connectionbetween HR and the period pickup con, tact of level VI of the rotary switch, that is contact 22 of this level.

(52) SRI restores, at SRl-ll, l2, signaling battery 90 to the selector contacts of the PS relays. SRI also restores, at SRII3, H, the normal branch of the energizing circuit to magnet DM although this circuit is still held open at PRI, 2. HR at its contacts HR-ll, l8 removes signaling battery from the contact points of the selector levels I through V of the rotary switch. HR at contacts HR l5, l6 breaks the energizing circuit to RR which, however, is now held operated. HR releases, atcontacts HR-I, 8 the transmitter lock magnet TL. HR at contacts HRFE, 6 opens the energizing circuit of magnet RS which is already broken at contacts 500 and 50d of cam 41.

(53) The release of magnet TL frees the tape feed mechanism of the transmitter and the transmitter pins.

(54) At the end of its release stroke, magnet TL opens contacts 53a and 53b thereby breaking the holding circuits for relays PR and RR.

(55) PR de-energizes and completes, at contacts PR|, 2 the energizing circuit to magnet DM.

(56) Magnet DM releases the distributor shaft 20.

('7) Shaft commences to rotate thereby causing resumption of normal transmission from the tape through to the distant printer.

The typical example of operation described just above is varied only in that by the operation of different combinations of relays, as has been described in detail, different pickup points or pickup contacts of the rotary switch are selected and due to such selection predetermined signals are sequentially transmitted from the contact points of selector levels I through V of the rotary switch to the line after which the various relays utilized in the operation are released in the same manner as was described in connection with the transmission of the period, and normal transmission resumed.

For example, if a hyphen is to be interpolated due to the operation of the end of line contacts 62, the pickup point 8 of level VI of the rotary switch is selected and from ,contacts 8 of the selector levels a shift signal is first transmitted. Then the rotary switch is stepped to point 8 at which the proper signal for causing the type bar bearing a hyphen in its upper case position to operate, is transmitted. Next the rotary switch steps to point In and the unshift signal is transmitted. Following this, the switch again steps ahead arriving at point II from which point on the selector levels I through V a carriage return signal is transmitted. Upon stepping to point I! a line feed signal is transmitted following which stepping to points l3 and I4 in order causes the pre-release relay PR and the release relay RR to operate thereby restoring normal operation in the same manner as described in connection with the transmission of the period.

While we have described a preferred embodiment of our invention and have limited the description to tape and page printer codes of particular variations and differences, it is to be understood that this description is not to limit the scope of our invention but that the limitations thereof are to be determined solely by the appended claims. Furthermore, although the illustrative example has referred solely to the use of a rotary switch as a secondary transmitter, it will be clear that other forms of secondary transmitters might be utilized, for example, a relay chain or a tape transmitter provided with a loop of tape. It will, of course, be clear that the methods for converting signals may be utilized without utilization of the methods of interpolating signals and that the reverse is likewise true. Furthermore, it will be understood that the methods for deleting the transmission of character signals when an erasure has occurred may be utilized either alone or together with the conversion and interpolation arrangements. It should also be pointed out that the arrangement described herein may be utilized in connection with a concentration board one section of which would be devoted to lines leading to receiving page printers. In this manner a relatively small number of conversion and interpolation units are capable of handling all traffic to a relatively large number of receiving page printers.

What is claimed is:

1. In a printing telegraph system having a transmitter, a distributor and a receiving printing mechanism and in which the code representation controlling the transmitter differs in certain characters from the normal operating code of the printing mechanism, means for converting the code representations of the certain characters comprising, in combination, a secondary transmitter and means to take control of the distributor from the transmitter and to place the distributor under control of said secondary transmitter to effect transmission of signals in the normal operating code of the printing mechanism.

2. In a printing telegraph system having a primary transmitter, a distributor and a receiving printing mechanism and in which the code representation controlling the primary transmitter differs in certain characters from tne normal operating code of the printing mechanism, means for converting the code representations of the certain characters comprising, in combination a secondary transmitter, means operable upon the presence in the primary transmitter of any of the certain characters to condition said secondary transmitter in accordance with the code conversion indicated, means to render the primary transmitter ineifective to control the distributor, means to lock the primary transmitter against operation, means to render said secondary transmitter effective to control the distributor, and means to lock said secondary transmitter in synchronism with the operation of the distributor to send a succession of signals in a code effective to cause the receiving printing mechanism to produce the certain character.

3. In a printing telegraph system having a transmitter, a distributor and a receiving printing mechanism and in which the code representation controlling the transmitter differs in certain characters from the normal operating code of the printing mechanism, means for converting the code representations of the certain characters comprising, in combination, means operable upon the presence in the transmitter of a code representation of any of the certain characters to stop the distributor and to render the transmitter ineffective to control the distributor, a rotary switch having a plurality of signaling contact levels and a control contact level, a self-interrupting circuit for said rotary switch, means to energize said self-interrupting circuit immediate-

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