US2139452A - Printing telegraph receiver - Google Patents

Description

Dec. 5, 1938. F. K'REQZER i 2,139,452

PRINTING TELEGRAPH RECEIVER Filed Aug. 1,. 1956 I M'gr/ maaamguum e7 64 6 81/ 14 Patented Dec. 6, 1938 UNITED STATES PRINTING TELEGRAPH RECEIVER Friedrich Kreuzer, Berlin-Oharlottenburg, Germany, assignor to Siemens & Halske, Aktiengesellschaft, Siemensstadt, near Berlin, Germany, a corporation 01' Germany Application August 1, 1936, Serial No. 93,827 In GeI-many August 23, 1935 7 Claims.

This invention relates to printing telegraph apparatus, and is particularly concerned with a printing telegraph receiver of the type termed "monogram printer, wherein the individual signs or characters are built up or formed by a plurality of sign or character elements in accord ance with predetermined series of impulses.

Teletypewriters in start-stop systems operate normally with the five-current-step alphabet and 10 print one letter or character according to agiven impulse combination. Such devices are extremely costly in production but furnish a transmission speed of from seven to eight signs per sec-- ond.

Other so-called facsimile-telegraph devices are known wherein a message is reproduced by combining electrical impulses upon a paper tape in the form of dots. larly adapted for wireless transmission which is especially subject to disturbances. A great number of impulses are used for each sign or character, necessitating a transmitting path capable of furnishing high transmission speed. This latter requirement cannot be met in the case of 25 normal communication lines which are provided according to international agreements for a.

transmission speed of 50 Baud.

An advantage of the previously noted "monogram printers, wherein the signs or characters are built up of individual characteristic sign elements, resides in the fact that fewer impulses are required to be transmitted for each sign. They are considerably cheaper in production than normal teletypewriter machines, thereby under certain operating conditions compensating for the disadvantage of lower transmission speed.

A great drawback of knownmonogram printers of the general type intimated above resides in the need for providing a special receiver mag- 40 netfor every sign element required for building up the signs or characters; the armature of each magnet functioning as a printer bar.

According to the instant invention, the resulting disadvantages are avoided and a considerable simplification of such devices is obtained by arranging the sign or character elements, required for the building-up or forming ofthe printed acter are successively printed, upon rotation of v the type wheel, on a suitable ribbon or tape within the same sign range or field thereof. The printing of the individual sign elements is caused by a Such devices are particuprinting bar or hammer which is controlled by an intermediate actuating means from a cam wheel rotating synchronously with the type wheel, depending upon impulses corresponding to the transmitted sign or character. The intermediate actuating means or link controlling the printer bar is actuated during the reception of a sign or character by a cam wheel according to the number of individual sign elements provided upon the type wheel. It is, for example, possible to form all letters and signs or figures with only fourteen sign elements.

The intermediate actuating member which .operates the printer bar or hammer is, in one embodiment of the invention, operatively governed'by the armature of the receiver magnet, depending on whether it is energized or deenergized, for the purpose of selecting the individual sign elements. It is particularly advantageous to connect the receiver magnet in a resting current circuit so that the printer bar is only actuated upon the release of the armature. The contacting operating surfaces of the intermediate actuating member and the printer bar are wedgeshaped in such a manner that a selecting period of only very short duration is required for the selection of a sign element.

According to another object of the invention, the receiver operates with the sender in start-stop operation, the printing of a given sign taking place within one revolution of the type wheel. A start impulse initiates the rotation of the type wheel, whereupon the printer bar is thrust against the printer tape or ribbon, pro-.- vided between the bar and the type wheel, at. each sign element required for fomiing the sign to be printed. The cam wheel controlling the actuation of the printer bar is likewise opera tively released by the start impulse and is stopped "again, together with the type wheel, by a stop.

impulse at the conclusion of one revolution. It

is possible, due to the indirect control of the printer bar, to use a receiver magnet system of relatively low magnetic strength; and it is likewise possible to operate the system with sum cient certainty and accuracy in spite-o1 impulse I in the transmissiondistortions that may occur lines.

The above noted objects and other objects and features will be brought out in the course otthe following detailed description rendered with ref erence to the accompanying drawin wherein: Fig. 1 illustrates the development of a type wheel, showing the characteristic sign elements provided thereon:

Fig. 2 shows a diagrammatic representaton of a receiver according to the present invention; and

Fig. 3 indicates another embodiment oi. the invention.

The type wheel I, shown in Fig. 1 peripherally developed, carries the sign elements required for forming or building up all signs or characters. Only fourteen sign elements elei 4 are required in the present case for building up all signs, including letters and figures.

The sender arrangement for such telegraph receivers consists essentially of individual cam disks 2 for sending out the series of impulses required for the selection of the individual sign elements. The sender cam disk 2 in the case of a start-stop synchronization transmits initially, upon starting its rotation, a startirnpulse by opening the contact 3. The type wheel I and the cam wheel 4 at the receiving end are thereupon released for one revolution. The means for releasing the type wheel I and the cam wheel 4 are not shown in detail, in order to avoid unnecessarily encumbering thedrawing. The intermediate member or link I is moved through the lever 9 up and down under the control of the cam wheel 4 and operatively engages the printer bar or lever 8, depending on whether or not the armature 6 of magnet 5 is in actuated position, thereby causing the printer bar to thrust the printer tape against the type wheel I to print that sign element on the tape which is at the corresponding moment positioned in front thereof or aligned therewith.

In the case of the resting current circuit for the receiver magnet 5 the printer bar 8 is actuated and thrust against the paper tape 9 only upon the receipt of no-current impulses. The armature 6 of the receiver magnet 5 remains actuated during spacer impulses (current steps), and the intermediate link 1 passes the lower end of the printer bar 8 upon operation of lever 9.

- Accordingly, no printing of a sign element will take place during spacer periods.

The cam wheel 4 is provided with cams corresponding in number to the number of sign elements on the type wheels-in the present case, fourteen cams. The individual cam disks of the sender are subdivided accordingly.

The operation may be explained in connection with this embodiment by describing the sending and receiving of the letter E. The sender cam disk 2, as noted previously, after sending the start impulse, closes the contact 3 by means of the cam portion sl to s3, thereby energizing the receiving magnet 5 and preventing actuation of the. printer bar 8 by moving armature 6 and link 1 into actuated position. Cam portion s4 of the cam disk 2 thereupon causes separation of contact 3, deenergizing magnet 5 and releasing armature 6. The printer bar I is now thrust against the type wheel I by the corresponding cam of wheel 4 actuating link members 9 and I, causing the printing of the sign element e4 which represents the upper horizontal line of the letter E. The sign elements e6, ell, and el4 are then successively printed on the same sign range or field of the paper tape 9' under control of cam portions s6, si l, and sl4, thereby causing the building-,up or forming of the letter E during one revolution of the type wheel I and cam disk 2. The paper'tape is then advanced by one space to the next receiving position.

In Fig. 3 is illustrated an embodimentof theirvention wherein the operation is essentially electrical. The contact II is operated by the receiver magnet l responsive to the receipt of the transmitted signs from the sender, thereby connecting the battery I! to contact 13. Contact I3 is closed by the operation of the cam disk l4 in accordance with the number of individual sign elements. Depending on whether or not the battery I2 is connected at that time by contact II, the printer magnet l will be energized and will cause the printing of a sign element by actuation of the printer bar IS. The cam disk I4 is shaped so that the contact I3 is closed only for short intervals corresponding to the middle portions of the received impulses. Connected in parallel with the printer magnet I5 is a condenser H, in order to assure the actuation of the printer bar It with suflicient safety even during the short impulse duration.

It is understood that specific embodiments have been shown and described above in order to guide others in carrying out the invention in practice. Changes are possible within the scope and spirit of the appended claims wherein is defined what is considered new and desired to have protected by Letters Patent of the United States.

I claim:

1. A printing telegraph receiver wherein com plete individual signs are formed of a plurality of fractional sign elements under the control of predetermined impulse series, comprising a rotatable type wheel, a plurality of characteristic sign elements disposed peripherally on said type wheel each element representing a fraction of a complete sign to be printed, a printing tape, a rotatable wheel having peripheral teeth corresponding in number to the number of fractional sign elements on said type wheel and rotatable therewith, printing means controlled by said rotatable toothed wheel, and impulse controlled means for additionally and selectively governing the actuation of said printing means during each revolution of said type wheel and said toothed wheel to print on said tape within the identical printing space thereof a plurality of said fractional sign elements to form within said space a predetermined complete sign.

2. The device defined in claim 1, wherein said printing means comprises a printer bar and an actuating member for engaging said bar to cause the selective printing operation thereof, the contacting surfaces of said printer bar and said actuating member being wedge-shaped to effect very short contacting duration for the printing of predetermined fractional sign elements.

3. In a printing telegraph system, the combination with a type wheel and printing means, 01' operating means which attempts to actuate said printing means to print all the characters on said wheel in succession upon a single rotation there- 01, a line circuit, and means controlled over said line circuit for rendering said operating means ineffective in respect of any desired number of said characters.

4. In a printing telegraph system, a rotatable type wheel having a plurality of characters, a

' cam having actuating surfaces equal in number to said characters, said cam being rotatable with said wheel, printing means adapted to be controlled by said cam, a line circuit and magnet controlled thereover as each cam actuating surface comes to operative position, and means controlled by said magnet for determining in the case of each .said actuating surface whether the said printing means responds or not.

5. In a printing telegraph system, a rotatable amuse type wheel having a plurality of different characters, a tape, a printer bar for pressing said tape against said wheel, actuating means for the printer bar operated as each character on said wheel passes the printer bar, a line circuit, and means controlled over said line circuit each time the actuating means is operated m1- determining if such actuation is effective to operate said printer bar.

6. In a printing telegraph system, the combination, with a type wheel and printing means,

of a reciprocating member, means for operating v said member as many times during each rotation said printing means, a line circuit, and mechanism controlled over said line circuit for rendering said last means efiective, or inefiective upon each operation of said member.

7. In a printing telegraph system, a type wheel having a plurality of partial or incomplete characters thereon, said incomplete characters be-- ing adapted for use in difierent combinations to build up complete, characters, and printing means a distant point for printing any desired combi-

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