US1360231A

US1360231A - Printing-telegraph

Info

Publication number: US1360231A
Application number: US823100A
Authority: US
Inventors: Charles L Krum; Howard L Krum
Original assignee: Individual
Current assignee: Individual
Priority date: 1914-03-07
Filing date: 1914-03-07
Publication date: 1920-11-23
Anticipated expiration: 1937-11-23

Description

C. L. AND H. L. KRUM.

PRINTING TELEGRAPH.

APPLICATION FILED MAR. 7, 1914. RENEWED 05c. 22.1919.

i Q m mg 0 0 T M MML CN' 1m (C v W E Z 3H 24L MW mm E w as m m P C. L. AND H. L. KRUM.

PRINTING TELEGRAPH.

1 WI} AWN C. L. AND H. L. KRUM.

PRINTING TELEGRAPH.

APPLICATION FILED MAR. 7, I914. RENEWED DEC. 22,1919.

1 ,360,23 1 Patented Nov. 23, 1920.

6 SHEETS-SHEET 3.

C. L. AND H. L. KRUM.

PRINTING TELEGRAPH.

APPLICATION FILED MAR. 7. 1914. RENEWED DEC. 22.1919.

[l /(5)365. Q 5; 8W JW .c. L. AND H. L. KRUMf PRINTING TELEGRAPH.

APPLICATION FILED MAR. 7, I914. RENEWED DEC. 22, I919.

Patented Nov. 23, 1920.

6 SHEETS-SHEET 5.

H I Hl I l r l l l l l l H l l l l l l I ll C. L. AND H. L. KRUM.

PRINTING TELEGRAPH. APPLICATION FILED MAR. 7, 1914. RENEWED DEC. 22. 1919.

Patented Nov. 23, 1920.

crating magnets.

umrso STATES PATENT; option] CHARLES L. KRUM AND HOWARD L. KRUM, or ciarcaco, ILLINOIS, Assreivons 'ro monxnum COMPANY, or onrcneo, nmmorsn CORPORATION.

PRINTING-TELEGRAPH.

Specification of Iietters Patent. Patented No 23 1920 Application filed March 7, 1914, Serial No. 823,100. Renewed December 22, 1019. Serial No. 346,770.

To all whom it may concern:

Be it known that we, CHARLES L. KRUM and HOWARD L. KRUM, citizens of the United States, and residentsof Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Printing-Telegraphs, of which the following is a full, clear, and exact description.

The invention relates to printing t e1egraphs of that type in which each station is provided-with rotatable transmitting and receiving switch mechanism, and in which suitable means is provided for maintaining the receiving switch mechanism at one station in synchronism with the transmitting switch mechanism at a distant station. The present invention seeks to provide an improved printing telegraph of, this sort which is simple in its construction and arrangement and which is eflFicientv and reliable in operation. The invention also seeks to provide improved station instruments having means for driving the rotating transmitting and receiving switches or sunflowers and means for maintaining the same in synchronism at two stations which are in communication. A further object of the inven tion is to provide improved means for con trolling, through the medium of a tape, the impulses \imparted to the line by the transmitting switch and to provide improved means controlled by the receiving switch in response to impulses received from a distant station for actuating selecting and op- With these and other objects in view, as will presently appear, the invention consists in the features of improvement hereinafterset forth, illustrated in the preferred form. and arrangement in the accompanying drawings and more particularly pointed out in the appended claims.

In the drawings, Figure 1 is a plan view of one of the station instruments. Fig. 2 is a View in side elevation with the transmitting and receiving disks shown in section.

Figs. 3, 4, 5 and 6 are detail sections on lines v is a plan view of a modification of the station instrument. Fig. 10 is a detail section on the line 10-10 of Fig. 9. Fig. 11 is a dia- I gram of the arrangement of the circuits at two connected stations' Fig. 12 is a diagram of the main line circuits employed in connection with the instrument shown in Fig. 9. 2

The improved station instrument is mounted upon a base plate 10. Inthe form shown in Figs. 1 and 2, the transmitting and receiving switches are mounted upon a common horizontal shaft 11 that extends centrally through annular or ring-like portions 12 of a pair of brackets 13 that extend upwardly from the base plate 10. At its outer end the shaft 11 is journaled in a U-shaped member 14 which is fixed to and extends across the annular portion or ring 12 of the outer bracket 13. At its opposite end, the

shaft 11 is journaled in an upright 15 that is mounted on the base plate 10. The contacts of the transmitter switch are mounted upon a ring or annular disk A which is fixed to the ring portion 12 of the inner bracket 13 and extends about the shaft 11. The con tacts of the receiving switch are mounted upon an annular-disk. or ring B of insulating material that is carried upon the ring portion of the outer bracket. The receiver disk B is preferably so mounted that it may be rotatably adjusted to a limited extent. For this purpose, it is held in place by a series of clips 16 which are fixed to the ring portion 12 of the outer bracket and which overlap and frictionally engage the reduced or rabbeted edge portion 17 of the disk. By means of a radially projecting handle 18 fixed to the receiving disk B, the latter may be adjusted in circumferential direction to a limited extent. A scale (see Fig. 1) marked from the upper edge of the adjacent fixed ring 12 assists in effecting the proper adj ustment of the receiver disk. H

Boththe transmitter and receiver disks A and B are provided with a circular series of contacts. Each has a series of correspond- Figs. 11 and 12) which are used in transmitting and receiving the different combinations or permutations which represent the different characters. The transmitter disk is also provided with two contacts 6 and 7 which impart the correcting and restoring impulses to the line. In the corresponding position, the receiver disk is provided with one long contact 6'. The disks are also preferably provided with an additional contact 8 for imparting and receiving warning signals. The contacts, as shown in Fig. 2, are recessed into the faces'of the disks, being held in place by bolts19 extending through the disks. Nuts 20 on the bolts secure clips 21 to the outer faces of the disks and by which the proper conductors are connected to the several contacts. The transmitter an extended portion 23' which carries a pad 24 of felt. A small quantity ofoil is placed 1 on these pads and as they sweep over the contacts, they serveto keep them free from dust. Current is transmitted to and from the switcharms a and b by insulated brushes 25 that are carried upon brush-holders 26, (see Fig. 6). These brush-holders are pivotally mounted 'upon an anglebracket 27 fixed to the base plate 10, and springs 28 interposed between the brush-holders and clips 29 on the bracket serve to yieldingly press the brushes into engagement with the hub portions or commutators 22 of the switch arms. The conductors leading to the brushes are connected to insulated clips 30 which are connected to the brushes by springs 31 and clips 32.

The operating shaftll of the station instrument is continuously driven, when in operation, by, a suitable motor. In the construction shown, a small electric motor C is mounted upon the base plate 10 and its shaft is provided with a fly-wheel 33 and a small pinion 34. The motor is also provided with a suitable governor (not shown) so that its shaft is rotated at the desired uniform rate of speed. The pinion 34 on the motor shaft meshes with a gear 35 in the main shaft 11. 'hen instruments such as shown in Figs. 1 and 2 are employed at two communicating stations, one station is provided with a corrected instrument and the other with a noncorrected instrument. In the non-corrected instrument, the gear 35 is fixed to the shaft 11, but in the corrected instrument, it is loosely mounted on the shaft and is connected thereto through means by which the shaft 11 can be retarded to thereby maintain the instruments at the two stations in synchronism. I

For this purposef the gear 35 is fixed to one end of a sleeve 36 which is loosely mounted on the shaft-and extends through the bearing on the upright 15. At its opposite end, the sleeve is provided with a gear 37 which meshes with a pinion 38 on the stud 39 (see Figs. 3 and 4). This stud is eccen- 6 5 trically fixed to a cross arm 40 that is fixed to the shaft 11. A short shaft 41 journaled in the end of the arm 40 carries at one end a star wheel 42 and, at its opposite end, a pinion 43 which meshes with the pinion'- 38. A retaining roller 44 engages the teeth of the star wheel 42. This roller is mounted upon an arm 45 which is pivoted on the arm 40 and which is connected thereto by a spring 45. The end 40' of the arm 40 is weighted to counterbalance the gearing on the opposite end of the arm. The spring 45' holds the roller in engagement with the star wheel and prevents the relative rotation of the train of

gears

37, 38 and 42, so that normally the shaft 11 rotates with the drive gear 35. But, by projecting a pin 46 into the path of movement of the star wheel, it and its shaft 41 may be caused to rotate through the space of one tooth and thereby, through the medium of the

pinions

42 and 39, retard the movement of the arm 40 and shaft 11 relatively to the drive gear 35.

The pin 46 (see Fig. 2) is mounted to slide longitudinally in a suitable guide in the upper end of a'bracket 47 that is fixed to the base plate 10. A double spool magnet D mounted upon the lower portion of the upright 47 is provided with an armature (i on a pivoted lever (13'. A headed stop pin 48 fixed to the upright extends through the armature lever d and a spring 49 coiled about the stop pin extends between the upright and the armature lever and normally holds the latter against the outer headed end of the stop pin. The upper forked end of the armature lever is arranged between collars 50 on the pin 46. Normally, the spring 49 holds the pin 46 out of the path of movement of the star wheel 42. But, when the correcting magnet D is energized, the pin 46 is shifted so that it engages the starwheel and retards the movement of the shaft 11 and of the transmitter and receiver switch arms a and b actuated thereby.

As hereinafter explained, the circuit of the correcting magnet is controlled by the combined operation of the line relay and of a switch controlled by a cam 0 upon the main shaft 11 of the instrument. In the construction shown, this cam is conveniently mounted on the shaft between the switch arm hubs 22 and is insulated therefrom and from the shaft. As shown, the cam is engaged by the upper, offset end of a switch arm E. .T his switch arm is mounted upon a brush-holder 26 which is similar in all respects to the holders for the brushes 25. previously described, and which is pivotally mounted therewith upon the angle bracket 27. The switch E cooperates with an adj ustable contact screw E which is carried upon an upturned lug 51 of a cross piece 52 that extends between the uprights 13. Through the greater portion of the revolution of the shaft 11, the cam (3 holds the brush E out of p'ulses imparted to the line are determined by a series of. switches which in turn are controlled by a perforated tape. The present invention provides improved means for driving the tape from the shaft 11. As

shown in Figs. 1, 2, 3 and 5, an upright plate 53 is fixed to one edge of the base plate 10 by angle brackets 54. A ledge 55 fixed to the outer face of the plate 53 forms a guide for the tape F. At its inner edge, the ledge is provided with a guiding shoulder 56 and at its outer edge with guide pins 57. In operation, the tape F is passed over the surface of the ledge between the shoulder 56 and the guide pins and beneath a short plate 58 that is fixed to the inner raised portion of the ledge 55.

A stud 59 is fixed to the upright plate 53 and projects outwardly over the plate 58. A series of washers 60 are eccentrically mounted on the stud 59 and a set of five switch arms f extend through the washers on one side of the stud 59 and are fixed in position by set screws 61. The upper ends of the switch arms are guided by a comb bar 62 that projects laterally from the upright plate 53 and are arranged to engage a set of five insulated contacts 63. The contacts 63 are adjustably mounted in a suitable support 64 that projects laterally from the plate 53. Rods 65 also project laterally from the plate 53 and a series of sprin s 66 extend between the rods 65 and the switch arms and tend to hold the latter in engagement with the contacts 63.

The lower pointed ends of the switches f extend through openings in the plate 58 and into the guideway for the tape between the plate 58 and the ledge 55. The tape F is provided with transverse rows of perforations which are varied, so that each of such rows represents a different character or signal. The switch contact 63 is so adjusted that, when no tape is present in the guideway, the switches will engage the contact and, when the tape is in position, the switches will be held out of engagement with the contacts unless the lower end of one or more of the switches drops into a perforation in the tape. When the lower end of any switch drops into a perforation, it is quickly shifted by its spring 66 into engagement with the corresponding contact 63 and when the imperforate portions of the tape pass its contact. T ese switches thus serve to select the impulses which are imparted to the line by the rotating transmitter switch a. The row of switches is arranged at right angles to the path of movement of the tape F, but the transverse rows of perforations F are arranged at a slight angle to the row of switches, so that the tape maybe continuously driven in definite timed relation to the operation of the transmitter switch arm.

The tape F is advanced by a pin toothed wheel 67 arranged beneath the guide ledge 55 and the teeth of which project upwardly through slots in the ledge and in the plate 58, and into engagement with the longitudinal row of perforations F in the tape. Feed wheel 67 is mounted upon the outer end of a shaft 68. This shaft extends through a vertical slot '69 in the upright plate 53 and is journaled in the depending end portions of a U-shaped bracket or support 70. The inner forked end of the support 70 is pivotally mounted upon the main drive shaft 11 and a worm 71 fixed to the shaft 11 meshes with a worm wheel 72 on the inner end of the feed shaft 68. The support 70 and parts carried thereby are normally upheld by a s ring 73 fixed thereto and to a stud 74 on t e upright plate 53. An adjustable stop screw 75 extends through a lug 76 on the face of the plate 53, engages the support 70 and holds the parts carried thereby in normal position. The outer end of the shaft 68 is knurled and forms a finger-piece by which the shaft may be depressed against the tension of the spring 73 to thereby depress the teeth of the pin wheel 67 below the upper face of the ledge 55,

whereon the tape is guided, to thereby permit the ready removal or insertion of the tape.

The outer end of the support 70 is pro-- vided with a pair of lugs 77 (see Fig. 5) which engage one arm 78 of a bell crank which is pivoted on the inner face of the upright plate 53. The other arm 79 of the bell crank is connected by a link 80 to a in 81, as most clearly shown in Fig. 7. is pin extends through a horizontal slot 82 in the plate 53 and engages the selecting switches 7 above the stud 59 whereon" the switches are pivoted. hen the outer ends of shaft 68 and support 70 are depressed, the pin 81 is moved against the switches by the connections described, so that their lower ends are lifted out of the path of movement of the tape. In this way, both the teeth of the feed wheel 67 and the selecting switches may be shifted to permit the ready insertion and removal of the tape. It should be noted that the arrangement is such that the feed wheel 61 and selecting switches f may be shifted without disengaging the gearing which drives the feedwheel shaft 68 and without stopping the moving parts of the instrument.

The selecting switches f which are variably actuated by the tape, serve to variably connect the

contacts

1, 2, 3, 4 and 5 of the transmitter disk to a source of current to thereby determine the oharacter'of the combinations of impulses imparted to the line as the transmitter switch arm a passes over these contacts. Preferably, a second set of five switches 9 (see Fig. 11) are interposed between the switches f and the transmitter disk and are operated bya set of magnets G. The switches f are all connected by a conductor 83 to one side of the local battery H and the contacts of these switches are connected respectively by a set of conductors 84 to the coils of the magnets G, the coils of the magnets being also connected to the ground or by a suitable return conductor to the opposite side of the battery H. The set of switches g are connected, respectively, by a set ofconductors 85 to the

contacts

1, 2, 3, 4 and 5 of the transmitter disk.

The characters are represented by permutations of five impulses of opposite polarity. For this reason, the switches 9 form pole changers, the contacts of which are connected by conductors 86 and 87 to the opposite sides of a divided battery H, the normally engaged or back contacts being connected to the negative pole of the battery and the normally disengaged or front eontacts to the positive pole thereof. The conductors 86 and 87 also directly connect the contacts 6 and 7 of the transmitter disk to the negative and positive poles, respectively, of the divided battery H. The gearing be tween the main shaft 11 and the feed wheel for the tape is such that the tape advances through the space occupied by a single transverse row of perforations during each revolution of the transmitter switch arm a. The switches f which are variably operated by the perforations variably actuate the magnets Gr and the pole changing switches g so that, as the transmitter switch arm passes over the

contacts

1, 2, 3, 4 and 5, different permutations of five impulses of opposite polarity are imparted to a conductor 88 which is connected to the brush 25 that engages the hub of the switch arm. At the end of each permutation, the switch arm it passes over the contacts 6 and 7, so that, at the end of each permutation of lmpulses, a negative impulse followed by a positive 1mpulse is always imparted to the line.

. The conductor 88, instead of forming the line conductor, preferably extends through a polarized pole changing relay P, the contacts 'of which are connected by conductors 89 .to 'the opposite sides of a divided line battery J and the tongue p of the pole The line circuit is arranged for duplex operation, so that messages may be transmitted} simultaneously in both directions. For this purpose, the pole changing switch 72 is 0011- nected by a conductor 90 to a pair of branch conductors 91 that lead, respectively, to the coils of a local main line relay B. This relay is polarized, one coil being connected to a grounded artificial line 92 and the other to a line conductor 93 which extends, as shown in Fig. 11, to a distant station and to the main line relay R thereof. Vith this arrangement, the main line relay at each station will, of course, only respond to current impulses imparted to the line circuit from the other station.

The switch tongue 1- of the line relay at each station is connected to a conductor 94 which leads from the local battery H. Its contact is connected by a conductor 95 to the brush 25 of the receiver switch arm 6. A set of branch conductors 96 connect the

contacts

1, 2, 3, 1 and 5 of the receiver disk at each station to a set of five selecting relays or magnets K. Extensions 96 of the conductors 96 are also connected to the contacts of a set of normally closed switches Z which are operated by a magnet L. These switches are connected by a set of conductors 97 to a set of five operating magnets M, and the contact 6' of the receiver disk is connected by a conductor 98 to the coil of an unlocking magnet N thatis associated with the set of selecting magnets or relays K. An extension 98 of the conductor 98 is connected to the normally engaged contact of a switch Z" which is also operated by the magnet L. This switch is connected by a branch conductor 99 to the coil of the magnet L and to the coil of a magnet T which is associated with the set of operating magnets M. The unlocking magnet N operates a normally closed switch at which is connected to the battery wire 83 and the contact of which is connected b a conductor 100 to the contacts of a serles of normally open, locking switches is which are operated by the selecting relays K and which are connected to the set of branch conductors 96. When any one of the selecting magnets K is energized, the corresponding locking switch is shifted and connects its coil through the medium of the conductor 100 and switch n. to the local battery. In this way, any of the selecting magnets which are operated remain energized and the branch conductors 96 cont-rolled thereby remain connected to the local battery until the unlocking switch It is opened.

The set of operating magnets M also control a series of normally open locking switches m. The contacts of these switches are connected by a conductor 101 to the contact of a normally closed switch 25 of an unlocking magnet T. The circuit of this "by a suitable return conductor to the local ance with the polarity. of the succeeding imbattery H. v

The local battery circuit through the re volving switch arm I) of the receiver disk is opened and closed by the tongue 1 of the local line relay R in response to the positive and negative impulses transmitted from'the distant station. When a negative impulse from a distant station passes through the line relay, its switch tongue closes the local circuit, and a positive impulse over the line circuit shifts the switch tongue and opens the local circuit. The receiver and transmitter switch arms a and b are operated in unison, so that they pass over the

contacts

1, 2, 3, 4 and 5 of the transmitter and {ireceiver disks in synchronism. As the switch arm b at either station passes over the

contacts

1, 2, 3, 4 and 5, of the receiver disk, the branch conductors 96 and selecting relays 70 will be variably selected and energized in accordance with the varied permutations of impulses transmitted over the line circuit from the other station and which represent selecting relay K at the other stati'onwill be energized and the first branch conductor 96 and its extension 96 will be selected and connected tothe local battery through the medium of the locking switch controlled by this magnet. .If the first impulse of the per mutation is positive, the relay K connected to the contact 1 of the receiver disk will not be energized. In a similar manner, the selecting relays K connected to the

contacts

2, 3, 4 and 5 are variably operated in accordpulses of the permutation.

In this way, as a. message is received at either station, one or moreof the branch conductors 96 are selected and connected to the local battery H during each revolution of the receiver switch arm I). At the same time, if the magnet L is deenergized and the switches Z closed, one or more of the set of conductors 97 are selected and one or 'more of. the operating ma nets M are energized. When anyone 0 the magnets M is energized, its locking switch is shifted to i the selected operating magnets remain energized independently of the selecting relays K until the unlocking switch t is ,opened,

The set of operating magnets M can be emcircuit through the receiver switch arm I) and through the conductor 98 and the unlocking magnet N. Switch n is then shifted to open the local circuit through the set of selecting relays K, so that the latter are then ready to receive the next' signal. This unlocking switch, however, does not open the circuits through the operating magnets M which have been selected, since the coils of these magnets are connected by their locking switches to the local battery through the unlocking switch If. The impulse from contact 6 of the receiver disk also passes by the conductor 98 and switch Z to the coil of the magnet v This magnet is thus energized to shift the switches Z and Z and thereby disconnect the circuits of the operating relays M from the circuitsof the se lecting relays K. Switch Z is also provided with a normally open contact which is connected to the local battery H by the conductor 101, so that, when the magnet is operated, the circuit through its coil is locked in closed condition and it remains energized until the normally closed unlocking switch t is opened. By thus separating the operating magnets M and the selecting.

relays K, the latter may be employed to build up one character, while the magnets M are operating to print or record the preceding character. The impulse from contact 6 of the receiver disk also closes the circuit through the conductor 98, its extension 98, switch Z", conductor 99 and the relay T and the circuit through the coil of this relay is locked in closed position by the shift of the switch Z. Relay T then closes its normally open switch t and the circuit is completed from the battery wire- 94 through switch If and conductor 102 through the coil of the unlocking magnet T.- It takes some appreciable interval of time to energize magnet T and subsequently energize the unlocking-magnet T, so that ample time is afforded for the. recording or printing-operation effected by the set of magnets. M, but when this operation is completed,

magnet. T shifts the unlocking-switch t and opens the circuits through the operating magnets and also through the magnets L, T and T. The switches of these magnets thendrop back to normal position and the set of switches Z again connect the set of relays K to the set of conductors 97 that conductors 96 that lead fromthe selecting lead to the operating magnets. The latter are then again actuated in accordance with the signal which has been previously built up by the selective operation of the rela s lt should be noted that the selecting relays actuated during a single revolution of the receiver switch arm are necessarily operated one after another as the receiver switch 7) passes over its

contacts

1, 2, 3, 4 and 5, and each relay K must be capable of operating during the interval that the switch is passing over a single contact. But the oper atingmagnets M that are selected by any one slgnal or permutation of impulses are connected to battery practically simultaneously when the divide magnet L is deenergized. The circuits of the operating magnets M are, as stated, then locked into connection with the battery by means of the locking switches m controlled thereby and, as the receiver switch 1) passes over its contact 6', the divide magnet L is actuated to M without reducing the speed of operation --of the receiver switch and of .relays K. The contact 6' the selecting of the receiver disk is preferably elongated, as shown, so

that the operations of the restoring or unlocking magnet N and of the divide magnet L are effected with certainty between separatesi nals.

In ig. 11, the circuits at two connected stations are diagrammatically indicated.

The instruments and circuits of both stations are alike, except that correcting means is provided only at the station Y. At this correcting station, the shaft 11 which operates the transmitter and receiver switches a and b is connected to the operating motor through the medium of correcting devices controlled by the magnet D, as previously described; The controlling switch E for this magnet is connected to the conductor 1 95 that relay switch 1' at this station. A conductor coil of the magnet Dto ground. At the ads from the contact of the line 103 extends from the contact E through the other non-corrected station, the shaft 11 and switch arms a and b thereon are driven directly from the motor.

Toefi'ect the operation of the correcting magnet D at station Y, both switches E and 7' must be in closed position for a suflicient interval of time to energize the coil of this magnet. Relayswitch 1' is of course controlled by the rotating transmitter switch (L at the non-corrected station X, while switch E is controlled by the cam c that rotates with the shaft 11 and switch arms a and Z) at the corrected station Y. The motor at station Y is preferably adjusted to run slightly faster than the motor at station X, so that the switches a and Z) and cam c at the former station tend to advance relatively to the switches a and F) at the latter station. As the receiver and transmitter switches pass over their

contacts

1, 2, 3, 4 and 5, and cam 6 holds the switch E away from the contact E so that the circuit of the correcting magnet is open at this point. As the transmitter switch at station X passes over its contacts 6 and 7 it invariably imparts to the line a negative impulse followed by a positive impulse, so that the relay switch 7* at station Y is closed for a brief interval, as indicated in Fig. 11. But in the Iposition of the cam 0 shown. the switch is still held open so that the correcting magnet is not operated. However, as shaft 11 and cam e at station Y advance. relatively to the shaft 11 and transmitter switch a at station X, the recessed portion 6 willpermit the shift of the switch E to closed position, at the same time that the relay switch 1 at this station is held in closed position by the correcting impulse imparted to the line by the transmitter switch a at station X. When both the switches E and 1" that control the circuit of the correcting magnet D are simultaneously closed for a sufiicient interval, the magnet is energized and the pin 46 carried by its armature lever d is shifted and operates to retard the movement of the shaft 11 and of the transmitter and receivin switches a. and b at the correcting station Y The negative impulses thus imparted to the line from the contact 6 of the transmitter disk A at station-X are always of the same length, since they are invariably followed by a positive impulse from the contact 7 of the transmitter disk. This negative iu1- pulse thus not only acts as a restoring impulse for the receiver at station Y, but also acts as a correcting impulse to maintain the instruments at both stations in synchronism. This impulse is always transmitted over the line when the two sets are in communication, even though no message is transmitted from station X. If desired, the motor at the corrected station could be driven slower than the motor at the noncorrected station andrthe device controlled by the correcting magnet D arranged to advancethe transmitter and receiver switches at the corrected station.

There is a certain amount of lag in the line circuit due to the interval of time required to charge the line and operate the relays in the line. For this reason, the receiver disk B ateach station is rotatably adjustable, as described, so that it may be placed in proper phase with the transmitter at the other station. In effecting this ad justment, the receiver disk is shifted by the handle 18 thereon and the limits of adjustment between which the receiving apparatus will operate properly are determined by reading the scale associated with the handle 18. The receiver disk is then turned until it occupies a position half way between the limits thus determined, so that the reversals of polarity imparted to the line by the transmitter at the distant station occur when the receiver switch is mid-way between the contacts of its disk. Preferably, as indicated in Fig. 11, the

character selecting contacts

1, 2, 3, 4 and 5 of the receiver disk are some what smaller than those of the transmitter disk, so that ample opportunity is afforded for reversals in the line circuit while the receiver switch is between its contacts.

In the arrangement indicated in Fig. 11, the correcting impulses pass over the line in one direction only from the non-corrected station X to the corrected station Y. Variations in the line lag equally effect the transmission of the correcting impulses and the transmission of character signals from station X to station Y, so that the receiver disk at station Y, when once set in proper position, need not be readjusted in case the line lag varies on account of varying weather conditions and the like. But such variations will cause variations in phase between the correcting impulses imparted to the line from station X and the character signals transmitted. in the opposite direction over the line from station Y, so that the receiver disk B at station X must be readjusted from time to time. For this reason, means is preferably provided for rotating the re:- ceiver switches at both stations faster than the transmitter switches, and correcting de-' vices are employed for retarding the re ceiver switch only. A station instrument of this sort is shown in Fig. 9. i The construction is substantially similar to that previ ously described, except that the transmitter and receiver switch arms a and bare mounted on separate horizontal shafts 11"- portions 12 of the disk supporting standards are both provided with U-shaped members 14 wherein the outer ends of. the shafts are journaled. The inner ends of the shafts are journaled in an upright'15', which also carries a stud 107 whereon the intermediate pinion 105 is mounted. Gear 104 is fixed to the shaft 11*, but the gear 106 is secured to the loose sleeve or hub 36 of the gear 37 on the receiver shaft 11". Gear 106 is slightly smaller than the gear- 104 and preferably has one tooth less, so that it rotates at a slightly greater speed. As in the construction previously described, the loose gear 37 is connected to its shaft by correcting earing which is controlled by the ma net The switch E and came for control ing the circuit of the magnet D are associated with the receiver shaft 11 and the feed mechanism for the tape is driven from the transmitter shaft 11.

The circuits at the connected stations are similar in all respects to those shown in Fig. 11, except that, as indicated in Fig. 12, each station is provided with a correcting magnet D, and a controlling switch E therefor. Vith this arrangement, the motors and the transmitter switches of both station instruments are operated at substantially the same speed, although they need not, and indeed cannot, be operated in exact synchronism. But it is essential thatthe speed of both motors shall be so nearly uniform that the gears 106 at each station will rotate faster than the transmitter shaft at the other station, so that the receiver switch 5 at each station tends to advance relatively to the transmitter switch a at the other station. As the transmitter switch a at each station passes over its contacts 6 and 7, the correcting impulses will be imparted to the line which will close the line relay switch '1' I at the other station, and the switches r and E at each station will cooperate to control the corresponding correcting magnet D, in the manner previously described, to retard the movement of each receiver switch I). In

this way, while the transmitter and receiver correcting impulses are transmitted in one direction only from a non-corrected station X to a corrected stat on Y, as indicated in Fig. 11, the. proper transmission of a message in the opposite direction is dependent upon the operation of the line relays R at both stations and of all repeating rela ys that maybe interposed in the line. This requires considerable nlcety ofadjustment in prop-' erly balancing the artificial linesconnected to the line relays, particularly if there are a number. of repeating relays employed.

But, in the arrangement indicated in Fig.

12, each transmitter disk imparts both correcting impulses and character selecting imfpulses or signals to the line and the trans instruments are used, it is frequently necessary to have both kinds at a single station that is connected with two or more other stations. With this arrangement, each transmitter switch mechanism imparts impulses to the line and thereby controls the correcting devices of the rotary receiver switch mechanism to which it is sending character signals, while its own operation is entirely under local control and is not affected by impulses imparted to the lineor by the receiver correcting devices.- It should also be noted that the rotary receiver switch mechanisms, except as controlled at inter- .Vals by the correcting devices, are operative under local control to eflect character, selections, and that the correcting devices are operative independently of spacing interva'ls between the successive selecting impulses of each character signal.-

As indicated in Fig. 11, the contact 8 of each transmitter disk is connected by a condu'ctor 108 to a switch key S, the contacts of which are respectively connected to the opposite sides of a divided battery H. The

contact 8 of each receiver disk is connected to a conductor 109 that extends through the coil of a lockin magnet W and through a signal lamp W and this conductor is also connected to a normally open switch w that is controlled by the magnet W. The contact of this switch is connected to the local bat tery H by the conductor 100 and locking swltch n. Each'key S is normally connected to the positive pole of the local battery, so

that positive impulses are imparted to the 'line as the transmitter switch passes over its contact'S, and the switch tongue 1' of the line relay 'R at the distant station is held in open position,'as the receiver switch 6 at the'latt'er station passes over its contact 8.

But if, for example, the switch 8 at station X.is depressed, a negative impulse is trans-.

mitted that closes the relay switch 7* of the distant station Y as the receiver switch I; of

this latter station passes over its contact 8. The circuit of the magnet W and signal I lamp W" at station Y is thus closed and is locked into connection with the local battery by switch w until the receiver switch arm 6 reaches its contact 6 and so energizes the unlocking relay N. In this way, the operator at either end of the line may signal the operator at the other end, and so notify the latter in case a message is not properly received.

Furthermore, these signal lamps may be employed in testing the synchronism of the instruments at the opposite ends of the line by operating both instruments without inserting any tape. Under such circumstances, the selecting switches f at both stations will be closed and positive impulses alone are imparted to the line by both transmitter switches (1, except when the latter pass over the contacts 6 when negative impulses will be transmitted. If the instruments are not in synchronism, one will advance relatively to the other, until the receiver switch I) at one station passes over its contact 8 as the transmitter switch a at the other station passes over its contact 6. In this way, the lamps at both stations will light at intervals when the instruments are not in proper synchronism.

It is obvious that numerous changes may be made in the details set forth without departure from the essentials of the invention as defined in the claims and" that certain features of the invention may be' employed without its adoption in entirety.

We-claim as our invention u 1. A station instrument for printing telegraphs comprising rotating transmitter and receiver switches, a common motor for continuously driving the same, correcting devices controlling said receiver switch, tape controlled means for selecting the transmitted impulses, and feeding devices driven by said motor for continuously advancing the tape in definite timed relation to the speed of operation of said transmitter switch.

2. A station instrument for printing telegraphs comprisin transmitter and receiver disks, each provided with a circular series of contacts, rotating switch arms cooperating therewith, a common motor shaft for driving said switch arms, correcting devices controlling the said receiver switch arm, a set/of tape controlled switches for selecting the transmitted impulses, and gearing driven by said motor for continuously advancing the ta e in timed relation with the rotation of sai transmitter switch arm.

3. A station instrument for printing telegraphs comprising rotating transmitter and receiver switch mechanisms, a common motor shaft for driving the same, electrically controlled correcting devices for said receiver switch mechanism, a set of tape controlled switches for selecting the transmitted impulses, a pin-toothed feed wheel arranged to engage a longitudinal row of perforations in the tape, and speed reducing gearing conanism relatively to said motor shaft, a mag- 1 net for actuating said correcting devices, a controlling switch for saidmagnet, a cam rotating with said receiver switch mechanism for actuating said switch, tape. controlled means for selecting the transmitted impulses,'and feed mechanism for the tape. geared to said transmitter switch mechanism.

5. In a printing telegraph in which the characters are represented by permutations of adefinite number of impulses of opposite polarity, the combination at each station, of rotating transmitter and receiver switches, a common motor shaft for driving the same, correcting devices for shifting said receiver switch relatively to said drive shaft, a controller for said correcting devices rotating with said receiver switch,

tape controlled switch for selecting the transmitted impulses, and feed mechanism for advancing the tape geared to said transmitter switch mechanism.

6. In a printing telegraph in which the characters are represented by permutations of a definite number of impulses of opposite polarity, the combination at each station of a line relay, rotating transmitter and receiver switch arms, contact disks cooperating with said switch arms, a common motor shaft for driving said switch arms, correcting devices for shifting said receiver switch arm relatively to said motor drive shaft, an actuating magnet for said correcting devices, a cam rotating with said receiver switch arm, a switch actuated by said cam and coiiperatingfwith said line relay to control said correcting magnet, tape controlled means. for selecting the transmitted impulses, and feed mechanism for said tape geared to said transmitter switch arm.

7 In a printing telegraph instrument, the combination of a rotatingtransmitter switch mechanism, tape controlled means for selecting the imparted impulses, a toothed feed wheel arranged to engage a longitudinal row of perforations in the tape, and gearing connecting said feed wheel and said transmitter switch mechanism, said feed wheel being shiftable to release the tape.

8. In a printing telegraph instrument, the combination of a rotating transmitter switch mechanism,- tape controlled means for selecting the imparted impulses, a tape guide,

a toothedfeed wheel for the tape projecting into said guide,and connecting gearing between said transmitter switch mechanism and said feed 'wheel, the latter being shiftable transversely out of the path of the tape during the operating of the instrument.

9. In a printing telegraph instrument, the

combination of a rotatingtransmitter. switch mechanlsm, a set of tape controlled switches for selecting the transmitted impulses, a tape guide, a-toothed' feed wheel for the tape projecting into said guide, operating shafts for said transmitter switch mechanism andsaid feed wheel, and gearing con-.

necting said shafts, said feed wheel shaft being spring-held in normal position to permit the shift of the feed wheel out of the path of the tape.

10. In a printing telegraph instrument, the combination of a rotating transmitter switch mechanism, a set of tape. controlled switches for selecting the transmitted impulses, a tape-guide, a toothed feed wheel for-the tape projecting into said guide, a drive shaft for said transmitter switch mechanism, a support pivoted on said drive shaft, a shaft whereon said feed wheel is mounted journale'd in said support, and connecting gears on said shafts, said support being path of the tape.

11. In a prlnting telegraph instrument,

the combination of a rotating transmitter switch mechanism,- a setof tape controlled switches for selecting the transmitted impulses, a tape guide, a toothed feed wheel for the tape projecting into said guide, connecting. gearing between said transmitter switch mechanism and said feed wheel arranged to permit the shift of the latter out of the path of the ta e, and means controlled by the shift of sai path of the tape.

- 12. In a printing telegraph instrument, the combination of a rotating transmitter switch mechanism, a set of tape controlled switches for selecting the transmitted imulses, a tape guide, a toothed feed wheel or the tape projecting into said guide, means for driving said feed wheel, and means for shifting said feedwheel and said selecting switches out of the path of the tape.

13. In a printing telegraph instrument, the combination of a rotating transmitter feed wheel for moving, said impulse selecting switches out of the switch'mechanism, a set of tape controlled switches for selecting the transmitted impulses, a tape'guide, a toothed feed wheel for the tape projecting into said guide, a drive shaft for said transmitter switch mechanism, a support pivoted on said shaft a shaft carrying said feed wheel journaled on said support, Worm gearing connecting said shafts, an adjustable stop for positioning said support, a spring for holding said support against said support being shiftable away from said stop for moving said feed wheel out of the path-of the tape and ashifter connected to said support for simultaneously shifting said selecting switches .out of the path of the tape.

14. In a printing telegraph instrument, the combination with a tape guide, of a toothed feed wheel therefor, a set of tape controlled switches. and means for shifting said feed wheel and switches out of the path of the tape.

15. In a printing telegraph instrument, the combination with a tape guide, of a toothed feed wheel therefor, a set of tape controlled switches, a shiftable support whereon said feed wheel is mounted and conand adapted to be shifted thereby into and out of engagement with said contacts, and means for simultaneously shifting said switches away from said contacts and out of the path of the tape.

1 17. A station instrument for printing telegraphs comprising rotating transmitter and receiver switch arms, cooperating contact disks. a common motor shaft for driving said switch arms, and correcting devices for shifting said receiver switch arm relatively to said motor shaft, said receiver contact disks being rotatably adjustable, tape feeding means geared to said transmitter switch arm, and tape controlled means for selecting the transmitted impulses.

18. A station instrument'for printing telegraphs comprising separate rotating transmitter and receiver switch mechanisms for respectively controlling sets of signal and character selecting circuits, a common motor shaft therefor, connecting gearing tending to drive said switch mechanisms at slightly difi'erent speeds, and correcting devices individual to the receiver switch mechanism for adjusting the same relatively to said motor shaft.

19. A station instrument for printing telegraphs comprising rotating transmitter and receiver switch arms, cooperating contact disks therefor, separate operating shafts for said arms. connecting gearing tending to rotate said shafts at slightly different speeds,

and correcting devices for adjusting said receiver drive shaft relatively to said gearing.

20. A station instrument for printing telegraphs comprising rotating transmitter and receiver switch arms, cooperating contact disks therefor, shafts whereon said arms are mounted, connecting gearing between said shafts, correcting devices for adjusting said receiver shaft and switch arm relatively to said gearing, and an actuating motor connected to said transmitter shaft.

21. A station instrument for printing telegraphs comprising rotating transmitter and receiver switch arms, cooperating contact disks therefor, separate actuating shafts for saidswitch arms, connecting gearing tending to drive said switch arms at slightly different speeds, and correcting devices for said receiver switch arm, said receiver contact disk being rotatably adjustable.

. 22. In a printing telegraph, the combination of a duplexed line circuit, separate, continuously rotating transmitter and receiver switch mechanisms at each station, and correcting devices brought into operation under the joint control of the transmitter switch mechanism at each station and the receiver switch mechanism at the other station for maintaining the same in synchronism.

23. In a printing telegraph in which the characters are of uniform length and represented by permutations of a definite number of impulses of opposite polarity, the combination of a duplexed line circuit, a transmitter at each station comprising a continuously rotating member operating solely under local control to impart the character signals and correcting impulses to the line, a receiver at each station operative to effect the character selections in response to the received signals, and controlling devices individual to said receivers and responsive to the correcting impulses transmitted by the transmitter at each station to the receiver at the other station for maintaining the same in synchronism. '24. In a printing telegraph, the combination of a duplexed line circuit, a line relay and an instrument at each station, each instrument comprising separate rotating transmitter and receiver switch mechanisms, and motor actuated means tending to drive the same at slightly different speeds, and means controlled by the combined operation of the line relay and the rotating receiver switch mechanism at each station for adjusting the latter relatively to the driving means and maintain the same in synchronism with the transmitter switch mechanism at the other station.

25. In a printing telegraph instrument, the combination with a rotating receiver switch and a drive -shaft therefor. of correcting devices comprising concentric members connected respectively to said shaft and said switch mechanism, a gear on one of said members, a cross arm mountedon the other of said members and having a counter balance on one end, a star wheel eccentrically mounted on the opposite end of said arm, two intermediate pinions mounted on said arm and connecting said'star Wheel to said gear, a retaining device mounted on said arm and yieldingly engaging said star wheel, a correcting magnet, and a pin connected to the armature ofsaid magnet andadapted to be shifted thereby into and out of the path of movement of said star wheel.

,arranged to be moved thereby into and out of the path of movement of said star wheel,

a controlling switch for said magnet, and a cam device rotating with said receiver switch mechanism for opening and closing said switch. 1

27. In a printing telegraph in which the characters are represented by permutations of a definite number of impulses of opposite polarity, the combination with a line circuit, continuously rotating transmitting and receiving switchmechanisms at opposite ends of said line circuit, means for maintaining the same in synchronism, a set of tape controlled pole changers for selecting the permutation of impulses transmitted, and a toothed feed wheel arranged to engage a longitudinal row of perforations in the tape,

, and continuously advance the same in definite timed relation to the speed. of operation of said transmitter switch mechanism.

28. In a printing telegraph in which the characters are represented by permutations of a definite number of impulses of opposite polarity, the combination' of synchronously rotating transmitter and receiver switch mechanisms at the communicating stations, a set of pole changers adapted to be controlled by the movement of a tape for selecting the transmitted signals, means for continuously advancing the tape in definite timed relation to the speed of operation of said transmitter switch mechanism, and a set of operating circuits selectively controlled by said receiver switch mechanism.

29. In a printing telegraph, the combination of continuously rotating transmitter and as receiver switch mechanisms at the communicating stations, means for maintaining the same in synchronism, a set of switches for controlling the transmitted impulses, a tape controlling said switches having a transverse series of perforations representing the different signals and relatively inclined to the set of switches controlled thereby, said tape also having a longitudinal row of perforations, and a toothed feed wheel geared to said transmitter switch mechanism and engaging the longitudinal row of perforations to continuously advance the same in definite timed relation to thespeed of said synchronously rotating transmitter and receiver switch mechanisms.

30. In a printing telegraph, the combination of a duple'xed line circuit, a line relay and an instrument comprising continuously rotating transmitter and receiver switch mechanisms at each station, means for maintaining the station instruments in synchonism, a set of switches at each station adapted to be actuated by a moving tape to select the transmitted impulses, feeding mechanisms for continuously advancing the tapes in definite timed relation to the speed of the rotating switch mechanisms,'and sets of recording circuits controlled by the receiver switch mechanisms.

4 31. Ina printing telegraph, the combination of transmitter and receiver switch mechanisms at communicating stations having rotary motor-driven members, line-controlled correcting devices for adjusting said rotary receiver member, a set of selecting magnets operatively' associated in order with the line by said rotary receiver member and thereby controlled in combinations to eifect the selection of all characters of a message, locking circuits for said magnets, recording means selectively controlled by said magnets, and additional magnets controlled by said rotary receiver member for controlling the recording means and for opening said locking circuits in advance of the complete recording operation.

32. In a printing telegraph, a receiver switch mechanism comprising a rotary member, line-controlled correcting device for adjusting said member, a series of local branch conductors and selecting circuits controlled by said switch mechanism, a set of operating circuits, and a dividing switch mechanism controlled by said rotatingv receiver switch member and arranged to alternately connect and disconnect said selecting and operating circuits. f

33. In a printing telegraph, a rotating receiver switch mechanism, a series of local branch conductors, selecting circuits controlled thereby, a set of operating circuits, relays interposed in said selecting circuits, operating magnets interposed in said operating circuits, a setof switches for connecting and disconnecting said selecting and operating magnets, a divide magnet for operating said set of switches, locking switches controlled by said relays and magnets, an unlocking switch for said relays controlled by said receiver switch mechanism, and an unlocking switch for opening the circuits of said magnets when the operation thereof is completed.

34. In a printing telegraph, in which the signals are represented by permutations of five impulses of opposite polarity-the combination of rotating transmitter and receiver switch mechanisms at each station, means for maintaining the transmitter at each station in synchronism with the receiver at the other station, each of said switch mechanisms having contacts for character selecting and restoring impulses and an additional contact for other signals, a pole changing switch key connected to the additional contact of each transmitter switch mechanism, a signal lamp and looking magnet connected to the additional contact of each receiver switch mechanism, a locking circuit for said lamp controlled by said magnet, and means controlled by the restoring impulse through the receiver switch mechanism for opening said locking circuit.

35. A station instrument for printing telegraphs comprising a transmitter and receiver switch mechanisms each having a rotating arm, a common drive member for said rotating arms, correcting devices for changing the position of the rotating arm of said receiver switch mechanism relative to said driving member, a set of tape-controlled pole changers connected to. the contacts of said transmitter switch mechanism and feeding devices for positively and continuously advancing the tape in timed relation with the rotation of said transmitter switch arm.

36. In a printing telegraph in which the characters are represented by permutations of a definite number of impulses of opposite polarity, the combination at each of two connected stations, of transmitter and receiver switch mechanisms having separate rotating members, a common drive shaft for said members, correcting devices under control of line impulses andoperative only on said receiyer switch member and adapted to change the position thereof relatively to said drive shaft, a recorder controlled by said receiver switch mechanism, and a setof pole changers connected to the-contacts of said transmitting switch mechanism for selectin the permutations of impulses.

31in a printing telegraph in which the characters are represented by permutations of a definite number of impulses of opposite polarity, the combination at each of two connected stations, of transmitter and receiver switch mechanisms having rotating members. a common drive shaft and connect ing gearing tending to drive said members at slightly diiferent speeds, correcting devices individual to said receiver switch member for changing the position thereof relatively to said drive shaft. means responsive to line impulses for controlling said correcting devices, a recorder controlled by said receiver switch mechanism, a set of tape-controlled pole changers for selecting the transmitted impulses and means for advancing the tape in timed relation with the operation of said transmitter switch mechanism. a

38. In a printing telegraph in which the characters are representedby permutations of a definite number of impulses of opposite polarity. the combination of a normally closed duplexed line circuit. a rotating transmitter switch mechanism at each of two connected stations for imparting character signals and correcting impulses to the line. a rotating receiver switch mechanism and a recorder controlled thereby at each station, a common drive member for actuating the rotating members of the transmitting and receiving switch mechanisms at each station at slightly ditlerent speeds and correcting devices at each station for changing the position of the rotating member of the receiving switch mechanism relatively to said common drive member, said correcting devices being under control of the correcting impulses imparted to the line by the transmitter switch mechanisms of the distant station.

39. In a printing telegraph, the combination with a normally closed duplex line circuit extending between two stations, a line relay and an instrument at each station, each instrument comprising transmitter and receiver switch mechanisms having rotating arms. sets of signal and character selecting circuits controlled respectively by said switch mechanisms. a common actuating motor geared to said arms and tending to drive the same at slightly different speeds and correcting devices for changing the position of said receiver switch arm relatively to said drive member, the correcting devices at each station having local operating circuits under the joint control of the local receiver switch mechanism and correcting impulses imparted to the line by the transmitted switch mechanism at the other station.

40. A station equipment for synchronous printing telegraph systems in which the character signals are of equal length and dis tinguished by permutations of two diii'erent line conditions extendingthrough a definite number of time intervals, said equipment comprising separate rotary transmitter and receiver members, sets of selectors corresponding to the signal intervals adapted to be operated in different combinations and cooperating respectively with saidmembers to transmit the character signals and effect the character selections in response to received signals, a common motor shaft and differential toothed gearing for driving said rotary transmitter and receiver members at different speeds and for actuating said transmitter member solely under local control, and a line controlled correcting device individual to said rotary receiving member for adjusting the same at intervals relatively to said motor shaft.

41. In a synchronous printing telegraph system in which-the character signals are of equal length and distinguished by permutations of five varied impulses, the combination of a normally closed line, transmitter switch mechanisms at connected stations each having a rotary member operative to impart the character signals and additional correcting impulses to said line,'a' separate receiver mechanism at each station comprising a set of selectors operable in diiierent combinations and a rotary member for associating said selectors in order with said line to effect the character selections in response to received signals, motor actuated means operative to continuously rotate said transmitter members solely under local control and to actuate said rotary receiver members under local control during the character selecting operations at slightly greater speeds, and individual correcting devices under control of the transmitted correcting impulses for retarding each of said rotary receiver members relatively to its driving means at intervals between the character selections.

42. In a synchronous printing telegraph system, the combination of a line, separate transmitter and receiver mechanisms at each of two connected stations, each of said transmitter mechanisms comprising a series of contacts, a'set of tape-controlled, signal selecting switches connected to said contacts and a rotary switch member cooperating with said contacts to impart to said line character signals of equal length and distinguished by permutations of a definite number of varied impulses, each of said receiver mechanisms including a set of selectors and a rotary member for associating said selectors in order with the line to efi'ect the character selections, means at each station operative solely under local control tocontinuously rotate said transmitter members and advance the tape in timed relation therewith and operative to rotate said re ceiver member under local control during the selecting operations, and correcting devices under control of transmitted line impulses and individual to each'of said rotary receiving members for adjusting the same relatively to its driving means.

tape controlled, changers connected respectively to certain- 43. In a synchronous printing telegraph system inwhich the character signals are of equal length and distinguished by permutations of a definite number of impulses'of opposite polarity,'the combination of a normally closed line, transmitter switch mechanism at connected stations each compris ing a circular series of contacts, a set of signal selecting poleof said contacts, a rotary member cooperating with said selecting contacts and with two additional contacts of said series to impart the character signals and additional controlling impulses to said line, and means operative solely under local control to .continuously rotate said switch member and advance the tape in timed relation therewith, a receiver at each station including a set of character selecting circuits, and a switch mechanism operative under local control during the character selections for associating said selecting circuits in order with the line, and means acting on the receiver switch mechanism at each station and responsive to the controlling line impulses transmitted thereto to maintain the same in synchronism with the transmitter switch mechanism at the other station.

445-. In a synchronous printing telegraph in which the character signals .are of equal length and distinguished by permutations of a definite number of varied impulses, the combination of a line transmitter and receiver mechanisms ateach of two connected station's comprising separate rotary members, and sets of selecting devices cooperating respectively with the rotary transmitter and receiver members to impart the signals to said line and effect the character selections in response to received signals, driving means for continuously rotating said transmitter and receiver members at slightly different speeds and for operating said transmitter members solely under local control, and individual correcting devices for adjusting the rotary receiver members at each station relatively to the driving means, each of said correcting devices being under the joint control of the local receiver memher and the distant transmitter member and brought into operation by the advance of one of said members relatively to the other;

45. In a synchronous printing telegraph system in which the character signals are of uniform length and distinguished by permutations of a definite number of impulses acter selecting circuits at each station and operative respectively to impart the character signals to said line and effect the character selections in response to received signals, each of said switch mechanisms comprising relatively stationary and rotary members provided respectively with cooperating contacts, means at each station arranged to continuously operate said rotary switch members and drive said rotary transmitter switch member solely under local control,iand an individual correcting device for the rotary receiver switch member at each station under the joint control thereof and of the rotary transmitter switch memher at the other station and brought into op eration by the advance of one of said n1embers relatively to the other.

. 46. In a synchronous printing telegraph system in which the character signals are of uniform length and distinguished by the permutation of five varied impulses. the combination of a duplexed line circuit. separate rotary transmitter and receiver switch mechanism and associated means at each station operative respectively to impart the character signals to said line and efi'ect the character selections in response to received signals, motor-actuated means arranged to continuously operate said switch mechanisms and operate said transmitter switch mechanisms solely under local control, individual correcting devices for adjusting the rotary receiver switch mechanism at each station relatively to its driving means, and an operating circuit for each of said correcting l devices under the joint control of the local receiver switch mechanism and the distant transmitter switch mechanism and brought into operation by the advance of one. of said mechanisms relatively to the other.

47. In a printing telegraph, a rotating receiver switch mechanism, correcting devices therefor, means controlled by line impulses for supplying currents to said switch mechanismanfl ffor controlling said correcting devices,'a"series of local branch conductors operatively associated in order with said line-controlled means by said switch mechanism, selecting devices responsive to impulses through said'branch conductors. a set of operating circuits and magnets adapted to be energized in combinations to effect the character selections, and switching relay means controlled by said rotary switch mechanism for connecting and disconnecting said selecting devices and said operating circuits.

48. In a printing telegraph, a receiver switch mechanism comprising a rotary motor-driven member, correcting devices for adjusting said member, line controlled means for supplying current to said switch mechanism and for controlling said correcting meansa series of local branch conductors operatively associated in order with the line-controlled means by said rotary switch member, a set of selectors adapted to be set a series of local branch conductors connected in combination by impulses through said branch conductors to select all characters of a message, corresponding operating devices controlled respectively by said selectors. an additional branch conductor controlled bv said rotary switch member and separate successively operating magnets controlled thereby for restoring said selectors and operating devices in the order named.

l9. In a printing telegraph. a receiver switch mechanism comprising a rotary motor-driven member, correcting devices for adjusting said member relative to its driving means. line-controlled means for supplying current to said switch mechanism and for controlling said correcting devices. a set of local branch conductors operatively associated in order with said line-controlled means by said rotary switch member during the selection of each character of a message, a corresponding set of magnets responsive in combinations to impulses through said conductors. relays interposed in at least some of said branch conductors, holding means for said relays. and means controlled by said rotary switch member at each character selection for restoring said relays and effecting the delayed operation of the corresponding magnets.

50. In a printing telegraph, a receiver switch mechanism comprising a rotary motor-driven member, correcting devices for adjusting said member. line-controlled means for supplying current to said switch mechanism and for controlling said correct i'ng devices, local branch conductors operatively associated in order by said switch member with said line-controlled means. a set of magnets responsive in combinations to impulses through said conductors, impulse restoring devices interposed in at least some of said branch conductors and means controlled by said rotary switch member at each character selection for restoring all of said devices and effecting the delayed operation of the corresponding magnets.

51. In a printing telegraph, the combination of a receiver switch mechanism comprising a rotary member, correcting devices therefor and a series of cooperating contacts, means controlled by line impulses for supplying current to said rotary member and for controlling said correcting devices,

to said contacts, corresponding sets of selecting and operating circuits controlled bv said branch conductors in response to line impulses, locking and unlocking switch contacts for said circuits, dividing switch contacts arranged to bring said selecting and operating circuits alternately into and out of operative relation, and an additional contact and local branch conductor cooperating