US2548720A - Telegraph system - Google Patents

Description

Filed Dec. 3l, 1947 h @fq l' r K 60 f6 fr 62 e7 e e L/l/L/Q/65 69 l 6 70 7/ V70( 7/ m73 V75 7E 50G/4A? GQrE/VE/Q Patented Apr. l0, 1951 UNITED STATES PATENT OFFICE Edgar Gretener, Zurich, Switzerland Application December 31, 1947, Serial No. 795,157 In- Switzerland May'Z,y 1946 61 Claims. l-

The present invention. is concerned;l with telegraph; systems. y

Itfis an object-of the invention to providermeans by which messages may be composed of a plurality of elementary symbols and transmitted; by ai series of' impulses of constant length.

It is an object of' theinvention to provideelementary symbols disposed on: axially movable stampsv mounted` peripherally on; atype carrying disk' which rotates synchronouslywith atransmitter.

Itis an object ofv thei'inventiorr to provide tele.m graph printing means by which the elementary indicia are printed in successionalongside each other during the rotation ofi the type carrying disk by axial movement` ofl the proper stamp at the position where the printed' elementaryl symbol is to appear.

Itis an object of the invention to mount movable type carrying members in journalsI of self lubricatingA materialV such as oil soaked sintered' metal.

. It is an object of the invention to provide a telegraph system in which printing is effected by rebounding blows, during thefcontinuous rotation of the type carrying` disk.,

Itis an object of the invention to providecontrol means such that-only asmall" fraction ofthe duration of an impulse is required for testing for the presence o-f current.

The usual Teletype machine based on the start and stop principle operatesv withv thev so-called five-unit code alphabet. Its chief' advantage: is its relatively high outputv of` about` seven strokes per' second. Such a machine involves the mechanical or electrical storing of the transmitted ve-unit combinations, their conversion and printing by some printing procedure. It an object of the present invention to provide ank apparatus in which the printing of` the individual symbols such as letters; figures or thelike is not done as a whole, but rather as a combination comprising the corresponding elementary sym-- bols. The results in a very considerable simplification in that the printing of each individual' symbol isv elected without storing and in direct response to the correspondingl transmitted current impulse. The storage elements of the apparatus are eliminated and the conversion or printing ofV the elementary symbols corresponding to the transmitted current impulseI combination isy accomplished in an extremely simplelmanner. v It is possiblewith the use of only fourteen1ele.- mentary symbolsfto constitute arr entire alphabet including gures and theessential supplementary combination codeand. if the start-stop; principleY is used, twomore impulse steps must be added for starting and stopping themachine. However, the simplifications effected are so extensive that this. factorA maybe ignored in many elds of' application where an' expensive machine may' be economically inadvisable. Y

It is a further advantage thatv asa. practical matter with a fourteen symbol alphabet', only'y a very-'limited number of possible combinations is ever required. The probability thata complete but* incorrect symbol will beprintedif the"trans mission is faulty is; therefore; much less than? in thev case of theve point-alphabet.l In most-in-V stances the'l transmission errorv clearly manifests itself'in garbled form although usually the symbol can be identied, despite its garbled' condition. The present application is based'fupon pat-r ent application Serial Number 11,538 filed" in Switzerland May 2, 1946'.

Other objects will appear as the description proceeds. In the drawings like numerals refer to like parts throughout.

Fig. 1 isa diagrammatic layoutof a telegraph printer in accordance with the invention.

Fig. 2' isA a graph showing the sequence and relative duration of the variouse'vents of the'several parts of the mechanism -of Fig. 1.

Referring to the drawings', the transmitter irrdicated broadly at I'comprises in principlea cam' disk Il with suitable dwells Iand valleys corre'-l sponding'to the impulse combination to be transmitted. As cam. follower I2l opensor closes electriccontacts i3; depending upon the position of cam disk III, the electric circuit containing contacts I3' is made or'broken. A telegraph printer according to the invention has for-instance fifty such cam disks and' cam follower contact-control arrangements, one for each of'the complete letter and related symbols to be printed and one each tovstart andv stop the-machine.v

The receiver vindicated broadly at. I4, comprises a. type carrying wheel or type revolver. 15j which mounts axially movable stamps I6x arrangedin a circlev around itsperiphery. l Stamps. I 6. are provided with. types |11 on their striking faces. A paper strip-l 8 restsagainst resilient support. roller I9 in a position tofl receive imprintsof types l1 which. arel inked by anl inking roller, wiper or similar means..V The-journal portions of wheel |15. which mount stamps I6. may be of oil soaked sintered. metal which isy self. lubricating.L Thus are adapted to receive the arm 24. The opposite end of hammer 28 is provided with a projection 21 cooperating with stop 28. A double ended S- 4 45 as control wheel 41 rotates. In the same manner the notches 26 restore hammer 20 by their action on projection 24. As hammer 28 and armature 36 both rotate clockwise under the action of operating disk 25 and control wheel 41, hook 35 engages pawl or projection 32 and the mechanism is ready for another striking action. The energy required for printing is derived from motor actuated shaft 48 and through the action of notches 26 and 46 of operating disk 25 and control 41 is stored in spring 49 and the energy required to actuate the armature 36 is stored in shaped lever 29 is pivoted at 39 on hammer 2D and is Ibiased in a clockwise direction by tension spring 3|. Lever 29 is provided 4with oppositely extending projections 32 and33. -Projection 33v j bears against arm 34 on hammer 26 and arrests,v

the clockwise motion of lever 29. Projectionor.` pawl 32 engages hook member 35 on one end of' -'tacts I3 in their circuit.

On thev side lof armature 36 opposite flattened portion 40` is an upwardly projecting tooth 45 cooperating with notches 46 vin wheel 41 which rotates in a counterclockwise direction on the 1 same shaft as disk 25.

The solution of the problem `presented by the inventionconsists in providing the receiver with a type carrying wheel I in the nature of a cylinder of a revolver, which carries in lieu of bullets fourteen movable stamps I6 bearing fourteen elementary symbols I1. The printing of the elementarysymbols is effected by axially moving the stamps I6. The system is operated by rotating the transmitter disk II and the disk and wheel 41 mounted on shaft 48 synchronously and in phase with each other. This provides a relationship between the phase position of the type carrying Wheel I5 and the incoming control impulses. 'I'he current impulses are received by magnet 42 which with armature 36 converts them into mechanical operations. Thus the release of armature 3,6 by magnet 42 permits the armature 36 to rotate counterclockwise under the action of spring 38 when tooth 45 is opposite a notch 46 into which'it can move. This action disengages hook member and projection 32 of S-shaped member 29 which permits hammer 26 to rotate counterclockwise under the action of spring 49 when arm 24 is opposite a notch 26 into which it can move. Hammer face or striking surface 22 strikes the end of stamp shank 23 a sharp blow. The rotation of hammer 20 is arrested by stop 28 which engages projection 21. Whichever stamp I6 is positioned opposite the printing point at the moment is moved axially in translation and the proper elementary symbol is printed. This action is dependent upon whether at that moment magnet 42 is energized by a current step impulse or is unenergized by stoppage of current flow at contacts I3 which have been opened by cam disk II and follower I2. v

It is important that the operation of the printing system be eiected without imposing any load on armature 36. This is achieved by providing suitable play between hook 35 and projection or pawl 32. As pawl 32 pivots counterclockwise it slides along the chamfered surface of hook 35 as hammer 20 is reset. Armature 36 is restored by the cam action of the Walls of notches 46 on tooth spring 38. In this manner very rapid snap action is obtained and there is no danger of binding of the parts or a hanging release ofk the movable parts.. Y I

klig .2 v illustrates the periodic correlation of the transmitter I0, armature control system or receiver i4 and the printer 50. Any relative displacement or phase shift between the effects produced at the transmitter ID and receiver I4 due to the time constant or lag of magnet 42 resulting from its inductance is Vneglected in this case. Graph 60 shows the square topped D. C. pulses from battery 43 due to the action of recesses 5I. rises 52 and dwell 53 of cam II through follower I2 on contacts I3 in battery circuit 44. The distance 6I may be taken as a unit of length in time. Graph 62 shows the time sequence and relative duration of the gaps or notches 46 into which tooth 45 can move. It will be noted that from the standpoint of the time sequence of the events the duration of any notch 46 in a tooth receiving position is relatively small compared with unit steps 6I. -Testing of the armature system to determine whether current is flowing is therefore eiected during a small fraction of the unit step 6I, so that iaultless transmission is assured even if the current impulses are very badly distorted. Graph 63 shows the movement of armature 36, the valleys 64 representing the time during which armature 36 is not attracted and tooth 45 has entered notch .46. The major portion of the time attened portion 4I) is held against the end of core 4l by the fieldV of magnet 42. Graphs 65 and 66 illustrate the functioning of the printer operating mechanism.' Graph 65 shows the events of notches 26 of control disk 25 as sharp drops 61 with gradualrises 68. Graph 66 shows the functioning of hammer 26 with sharp hammer action at 69 and a relatively long recovery or resetting period shown by the slow rise at 10 and the dwell at 1I. `This of course greatly reduces the instantaneous demand load on shaft 48; Graph 12 shows by pips 13 that the printing of the elementary symbols is effected by short sharp rebounding blows of hammer 20. When the type I 1 strike the paper I8, stamps I6 rebound very rapidly under the action of resilient support roller I 9 thus producing an elastic blow not unlike that of the small felt hammers of a piano on striking a note. O ver the last portion of its travel a stamp I6 moves freely, giving up a portion of its kinetic energy when it strikes paper I8. Stop 28 and projection 21 arrest hammer 20 before type I1 strikes paper I8. This action permits printing as the type carrying wheel I5 is rotating and eliminates the necessity of stopping it for printing. It is-clear that this feature greatly simplifies the device. Lapse of time is indicated by the arrow as one proceeds along the graphs from left to right in the normal manner. As mentioned above a disc Ii with the requsite cam events thereon isprovided. for each letter or related symbol represented by v`a corresponding actuating key on the key board of the telewriter. Each such letter, gure or the like is built up by the combination of from one to ve of the elementary symbols Il. The letter R for example requires ve elementary symbols or signs and the corresponding cam disc II for R will have ve depressions 5| positioned to actuate hammer 2t and the rive component stamps I6 in sequence as they are positioned by the bevel gearing on shaft 43. Paper strip I8 remains stationary during the rotation of each cam disc I! and is imprinted with the required one to rive elemental symbols I1 constituting a selected letter. On release of the letter key in the key board paper strip I8 is advanced in the normal manner well known in the type writer and tape machine art. Letter key interlock maintains the strip I3 in one position during the rotation of a selected cam disc l I.

The above description sets forth one form the invention may take and is presented as illustrative and not as limiting. The claims are intended to set forth in generic terms the specic structures described above.

I claim:

1. In a telegraph receiver, two synchronized control wheels, an armature adjacent one of said wheels mounted for movement relative thereto, a coil, said coil and one of said wheels jointly controlling the movement of said armature, printer actuating means adjacent the other of said wheels and mounted for movement relative thereto, interlock means releasably engaging said armature and said printer actuating means, said other of said wheels controlling the movement of said printer actuating means whereby intelligence may be caused to be printed.

2. In a telegraph receiver, two related control wheels, magnetic eld producing means, an arm mounted for movement under the joint control of said means and one of said wheels, printer actuating means mounted for movement under the joint control of said arm and the other of said control wheels whereby intelligence may be caused to be printed stamping means having characters thereon, movable mounting means carrying said stamping means for presenting various characters to be printed by said printing actuating means.

3. 'I'he combination set forth in claim 1, said control wheels having notches therein of such character that the time for testing whether a given intelligence should be printed is :of the order of live percent of the pulse duration for each intelligence unit.

d 4. The combination set forth in claim l, means associated with said controlr wheels, said armature and said printer Iactuating means whereby 'the time for testing whether a given item of intelligence should be printed is less than twenty percent of the pulse duration assigned for each intelligence item.

5. The combination set forth in claim l, movable indicia carrying means, a plurality of inl dicia bearing stamps movably mounted on said carrying means, said printer actuating meansv comprising hammer meanspositioned to strike said stamps sequentially a short` sharp blow, stop meansr positioned to interrupt the action f of said hammer means on said stamps and leave said stamps free to imprint indicia with a rebounding blow as they are carried along by said carrying means, means to restore said stamps to an initial position and synchronizing means connected to coordinate the positioning of said stamp carrying means and the action of said hammer means.

6. In printing means for a printing telegraph, movable indicia carrying means, a plurality of indicia bearing stamps movably mounted on said carrying means, hammer means positioned to strike said stamps sequentially a short sharp blow, stop means positioned to interrupt the action of said hammer means on said stamps and leave said stamps free to imprint indicia with a rebounding blow as they are carried along by said carrying means, means to restore said stamps to an initial position and synchronizing means connected to coordinate the positioning of said stamp carrying means and the action of said hammer means.

. EDGAR GRETENER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,165,663 Goldberg Dec. 28, 1915 2,099,771 Rea Nov. 23, 1937 2,139,452 Kreuzer Dec. 6, 1938 FOREIGN PATENTS Number Country Date 766,104 France June 21, 1934

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