US2307099A - High speed telegraph system - Google Patents

Description

Jan. 5, 1943- s. APPERLEY HIGH SPEED TELEGRAPH SYSTEM Fil ed Sept. 27, 1959 2 Sheets -Sheet 1 l 1 i i lNVENTOR ATTORNEY Jan. 5, 1943. s. APPERLEY 2,307,099

HIGH SPEED TELEGRAPH SYSTEM -Filed Sept. 27, 1939 Z-Shaats-Sheet 2 P lNVENTO R 650%?RLE Y BY ATTORNEY Patented Jan. 5, 1643 HIGH SPEED TELEGRAPH SYSTEM *ourne, Victoria, Australia,

aspire t of;

gnments, to Radio Cor- New York, N. Y.

E7, 1939, Serial No. 296,758

in AQBu suA-\Q September 27, 1938 4 Claims.

This invention relates to high speed telegraph systems and more particularly to means for materially increasingthe eifective speed of their 'operation.

In one known automatic telegraph system, received signals are caused to actuate a re-periorating machine which records the signals in the form of perforations in a moving tape which is then caused to actuate a printing machine to convert the signals to Roman characters, or alternatively, to actuate a second transmitter where it is desired to relay the message over a second channel.

In such known system the working speed is limited to that at which any one function in the sequence of operations can be performed. In practice the maximum speed of operation is governed by that of the re-perforating and/or printing machine.

If the main signalling channel comprises a radio link, speeds greatly in excess of the maximum speed of such printing systems are possible over that portion of the system. It is in fact common practice to transmit and receive signals on radio circuits at speeds up to 300 words per minute, and such signals are usually recorded in the form of ink markings representing Morse charscters or otherwise, on a paper tape, by means of an lmdulator.

The speed of signalling over a radio channel is usually governed by atmospheric conditions, prevailing at any given time, and as such conditions may vary considerably over a given period, it is evident that if delays are to b avoided, advantage should be taken of those periods when conditions are favourable to operate the circuit at maximum speed. This means that during periods of good reception when the signalling speed exceeds the maximum at which automatic re-perforating, printing or re-transrnission is possible, it becomes expedient to transcribe manually the message from the undulator tape; or, if the message is to be re-transmitted over a second channel, to prepare manually a perforated tape.

It is an object of the present invention to provide means for overcoming the above difficulties and limitations, and to enable a telegraph system to operate automatically at the speed of the fastest link in the signalling channel.

More specifically it is an object of this invention to provide means for converting graphical representations of Horse or other code characters to corresponding electrical impulses and to cause said impulses to control a transmitter or automatic printing apparatus.

The invention comprises means for receiving and recording telegraph signals in the form of ink markings or otherwise on a paper tape, means including a light source and photoelectric cell for converting the said markings to corresponding electric impulses, and means for utilising the said impulses to actuate or control one or more automatic printing instruments or further transmitters.

In cases where it is desired to convert automatically the received signals to Roman characters at the receiving station, the signals are received and recorded as ordinarily on an undulator tape at the maximum speed of the signalling channel and undulator. In accordance with this invention the undulator tape is then divided into suitable lengths and these are fed separately to individual scanning devices whereby the recording on the tape is converted at a suitable speed to electrical impulses which are replicas of the received signal impulses, and used to actuate a plurality of automatic printers.

In cases 'where it is desired to re-transmit or relay the message over a further circuit the converted signal impulses may be caused to actuate re-transmltting apparatus.

In order to convert the recorded signals on the undulator tape to electrical impulses the said tape is caused to pass in close proximity to a suitable source of illumination, the light from which is directed onto the markings on the tape and is then reflected to control a photo-electric cell, the output from the latter being amplified to a strength suitable to operate a reperforator, automatic printer or transmitter.

For a more complete understanding of the invention and the manner in which it is to be carried into eil'ect, attention is now directed to the accompanying drawings, in which:

Fig. 1 is a diagrammatic representation of a light system arranged in accordance with a preferred application of this invention, and

Fig. 2 is an isometric view serving to show the construction and operation of one type of scanning head suitable for use in conjunction with the light system of Fig. 1.

Referring to Fig. 1, light rays from a light source 3 are concentrated by means of a condenser 4 onto a diaphragm 5 having an aperture 1. The image of the aperture 1 is focussed by means of a lens or optical system i onto a tape it bearing the signal markings 28 (Fig. 2) which are to be converted into electrical impulses and which, as they pass the aperture I5, are exposed to the light rays irom the source 3. The signal markings 29 on the tape H are such as will cause a variation in the intensity of the light reflected therefrom. The light rays which are reflected from the signal tape H are focussed by means of a further lens or optical system 9,

' ture i between the light source 3 and the aperture i5 is described. Whilst this is the preferred arrangement it is to be clearly understood that the aperture 1 may be dispensed with and light rays from the light source 3 iocussed onto the aperture l5 direct if desired.

In practice, it is preferred that the light source 3, condenser 4, aperture 1 and lens 6 of the light source (also the light sensitive cell In and its associated lens 9) should be adjustable with respect to the tape H in the aperture II.

The aperture I5 is itself, in the present example, arranged for independent adjustment, such that its position with respect to the tape H may be varied in a direction coincident with the movement of the tape l4 and also in a direcion at right angles to the movement and in the plane of the tape it. This independent adjustment oi the aperture l5 compensates for any mis-alignment of the components employed for directing the light rays onto the aperture I5. Further, it enables the aperture is to be adjusted to that section of the incident light beam which contains the greatest concentration of light rays, and so ensures thatoptimum amount of light is reflected to the light sensitive cell I0.

The components forming the light system oi Fig. 1 may be mounted in any convenient and well-known manner such as will enable them to i'ullfil their individual functions in directing a concentrated beam of H nt onto the aperture l5, from the light source 3, and producing the desired response by the light sensitive cell 80 to light rays which are reflected from the signal tape H in the aperture IS.

The light system of Fig. 1 is preferably enclosed so as to protect the light-sensitive cell IO irom the influence of extraneous light. Those parts of the system which are exposed to the light rays are preie'rably blackened or otherwise treated to prevent undesirable reflections on the light sensitive cell it.

The aperture t5 and associated lighting system, is located behind the scanning head of Fig. 2 in such a manner that the tape l4, carrying the signal markings 29 which are to be converted, passes over the aperture l5, and in the course base member 23.

markings are on that side of the tape H which 'is adjacent to the aperture II.

The tape It runs in a groove 30 which is provided in the tape came! I! in order to prevent undesirable lateral movement of the tape ll.

The said tape is tensioned in the runnin groove ber 21 (which is supported for angular rotation in a direction at right angles to the movement of the tape I4) by means of supports 25 which are attached to or form an integral part of a sliding The mounting of the gate ii and tensioning springs I2 is such that in the of its progress the signal markings 29 on the tape it produce a corresponding variation in the intensity of the light rays reflected from the aperture it onto the light sensitive cell 63.

Referring now to Fig. 2, the tape i4, carrying the signal markings 29 which are to be converted, is passed over the aperture is through a tape carrier I! in a manner such that the said signal 5 effective position of the lever II, as shown in Fig. 2, the inner surface oi the gate H as well as the tensioning devices I: contact with the surface of the tape 94. The pressure of the gate ii and the tensioning devices I! on the tape H is adjustable by means of the adjusting screw ii, which passes through the gate Ii and projecting beyond the inner surface thereof presses against the carrier plate ll. The pressure of the gate l I and tensioning means l2 on the tape ll should be such as wiil substantially eliminate undesirable movement of thetape H in front of the aperture ii without placing too great a load on the motive means propelling the tape through the carrier H, or imparting such tension as would retard the free movement of the tape and result in breakage thereof.

The carrier :1, as well as the gate supports 2!,

is fixedly mounted on the sliding base 23, which is supported in-guides 2d, 23 for movement in a direction at right angles to the movement of the tape H.

Depending upon the nature of the graphical signal representations on the tape H it may be necessary to adjust the position 01' the latter with respect to the scanning aperture II to permit scanning of any portion of the tape betweenits two side edges. For'example, the signal markings indicated on the tape H are those produced by an undulator. The side of the marking indi cated by M is the marker signal, whilst that shown as S is the space signal. I! it is desired to scan either one of these sides for the purpose of producing corresponding electrical impulses,

the tape H must be moved to one side or the other to bring the relative portion thereof over the aperture 85. 1 This involves the bodily movement in a lateral direction of the tape carrier H and its associated apparatus. This adjustment is provided for in thepresent example by the lever is. This lever is pivotally mounted on the fixed member 26 for angular rotation in a horizontal plane and carries on its under side a cam (not shown), which projects into an elongated slot is in the slide member 23 supporting the carrier ill and gate ii.

.When the lever id is in the position shown in Fig. 1, the central portion, of the tape it is located over the aperture 55. Psotationalmovv ment of the lever is in a clock-wise or anti-clockwise direction will shift the carrier ii laterally with respect to the aperture l5, and to one side or the other depending upon the direction of movement of, 58. The lever it may be locked in screw 28, which tightens the bearing wherein the lever ll pivots.

The aperture is is a longitudinal slit in a rectangular receptacle 8 (Fig. l) which is dimensioned to fit into an aperture in the member and a slot in the carrier H in a manner such as will bring the aperture IS in contact with the tape it. In the present example the external I 3 In carrying out the invention the aperture II may be arranged to scan either the upper surface of the receptacle 8, which contacts with the signal tape i4 and in which also the aperture i5 is located, is convex and protrudes through apertures in the slide member 23 and the carrier i! into a concavity in the gate ii.

To facilitate lateral movement of the carrier H, the aperture in the slide 23 and carrier I1 is extended in a lateral direction to an extent necessary to provide for the full lateral movement of the carrier II as previously described.

The operation of the arrangement is as follows:

Signal markings 29 representative of the intelligence to be conveyed are imprinted on a tape i4, either manually or electrically. The marking 29 may be straight Morse characters or undulating as for example those produced by signal responsive instruments normally employed in high speed telegraph systems and commonly known as undulators.

The lever i3 is operated to lift the gate Ii and associated tape tensioning devices II.

The tape it is passed through the groove II in the carrier plate II in a manner such that the signal markings II on the tape ll are on that side which is adjacent to the aperture I.

The end of the tape i4 is attached to some form oi motive means (not shown) generally employed tor-pulling the tape through the carrier. The

lever I8 is operated to line up the aperture I! with that portion of the signal marking which is to be scanned. The gate ii and tensioning means I! are now closed on the tape it and are held in position by a spring catch or other suitable means (not shown). The tension of the gate ii is adjusted by means of the screw it to suit the thickness of the tape employed.

As previously stated, the light rays from the light source 3 are iocussed onto the aperture is and the rays reflected from any matter appearing therein are iocussed onto a light sensitive cell II, which is connected in the input 0'! a suitable ampliiier 3i.

Asthesignalmarkings Ilonthetapell pass over the aperture II, the intensity 0! light or lower horizontal sections.

It is further possible by the use of two apertures each having its own light system as described in Fig. l, to scan simultaneously both the upper and lower horizontal portions of the tapes and to utilise the converted electrical impulses in the output oi each unit to carry out individual functions or to act as a check one against the other.

As an example of the operation of a system embodying the present improvements, it will be assumed that the speed of the signalling channel is 300 words per minute, and that of the printer or re-transmitter 100 words per minute.

In these circumstances three scanning units would be employed. The tape from the undulator produced at 300 words per minute would be divided into suitable lengths and individual lengths ted to. individual scanning devices so that the speed of the whole system would then be 300 words per minute and the system would becompletely automatic in operation and there would be no necessity to transcribe manually.

I claim: i

1. A scanning device for tape which has signal markings thereon, comprising a tape guide member, an apertured gate, means for moving the tape longitudinally past the gate aperture, means for positioning the gate in either or two alternative fixed lateral positions with respect to the guide member, means-10! directing light through the aperture of the gate thereby to scan a portion of the tape to one side only of its longitudinal center line, and photo-electric sensing means responsive to variations in the intensity of light reflected by said tape and outwardly reflected thereirom varies in dependence. upon the variations of the signal markings on the tape. This variation in intensity of the reflected rays impinging on the light sensitive cell ll produces corresponding current variations in its output circuit, which are amplified in the associated amplifier 3i and utilised to actuate or-control a-printing instrument, re-periorator or further transmitter.

-Where signal marked tape, which is produced by a signal operated undulator, is employed, that portion M of the markings I! on the undulator tape I, which lies closely adjacent to a line drawn through the upper horizontal section of the markings, represents a graphical replica oi the signals received, whilst that portion s of the markings which lies adjacent to ,a line drawn through the lower horizontal section of the markmgrepresents the spadngperiods between the signal characters of the received signals.

through said aperture.

2. A device according to claim 1 in combination with a tape bearing a graphic representation' of marking and spacing signals, said gatemoving means being adjustable to scan either the marking or the spacing elements 0! said signals.

3. A telegraph-tape scanner having a tape guide member and an aperturedgate; an optical system including a light source arranged to illuminate the tape area which is framed by the aperture in said gate, a photo-electric device disposed in the path of light rays reflected by the tape through said aperture, said tape being marked with telegraph signals, and means for laterally shifting the position or said gate into one or the other of two fixed positions, thereby to sense a predetermined longitudinal track on said tape.

4. A telegraph tape scanner having an aperdistinctively responsive to reflections or light through the aperture of said gate, a tape bearing marking and spacing indicia which are disposed thereon in two separate longitudinal tracks, said indicia being selectively exposahle to light from said source through said aperture in dependence upon the lateral position of said tape with respect to said aperture, and means for moving said tape longitudinally past said aperture.

onoacr:

Images