US2462904A - Telautograph system - Google Patents

Description

Patented Mar. 1, 1949 TELAUTOGRAPH SYSTEM Leo Rosen,nited States Army, South Arlington, Va.

Application November 19, 1943, Serial No. 510,909

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 4 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to improvements in electrical apparatus, telautograph systems and the like.

Heretofore, telautographs, considered generally, have been inadequate in that they did not provide a faithful reproduction, and they required special wiring between the sending instrument and the receiving and reproducing apparatus.

It is, therefore, an object of this invention to provide a telautograph which will furnish an accurate reproduction of the message or other material intended to be transmitted.

Another object is to providea telautograph operable over ordinary communications lines, without special wiring.

A further object is to provide a telautograph operable by signals suitable for Wireless communication.

It is also an object of the invention to utilize a frequency change in a signal furnished by the originating apparatus for directing and limiting the movement of the reproducing means.

These and other objects are attained by the novel combination and arrangement of elements hereinafter described and illustrated in the accompanying drawings, forming a part hereof, and in which:

Figure l is a block diagram of the apparatus for producing the pattern to be transmitted;

Figure 2 is a block diagram of the receiving and reproducing apparatus.

With reference to the drawings, and particularly to Figure 1, I0, represents a Writing mechanism including a stylus I I adapted to be moved vertically in a slot I2 in member I3 and simultaneously in a'slot I4 in member I5, horizontally. A movement of the stylus is, in other words, accompanied by some characteristic displacement of one or both of the members I3 and I5. Such displacement is transferred to the racks I8 and II, by members I3 and I5, respectively, and thence to the pinions I8 and I9.

An oscillator 25 is arranged to have its normal frequency varied by a capacity change in the variable condenser 26, and the latter element is linked in any desired manner with pinion I9, so that vthe frequency of oscillator 25 becomes a The direction of movement of this Another oscillator 30, similar to oscillator 25, and with means 3| for varying its frequency, is linked to pinion I8, so that the output of this oscillator is a function of the displacement of stylus I I along the Y-aXis. The frequency range of oscillator 30 should differ from the range of oscillator 25.

The outputs of the two oscillators are fed into modulator 35, together with the output of carrier oscillator 35', and from there to the transmitter 36. The exact type of transmitter is unimportant. The signals can be carried equally well over wired and wireless systems.

In Figure 2` are illustrated the receiving and reproducing elements of the invention. Receiver 39 is conventional, its exact nature depending upon whether Wired or Wireless signals are utilized, etc. A writing apparatus similar to the apparatus IIJ of Figure 1, including a stylus 40 and pinions 4I, 42, and cooperating racks, is provided. In this case, of course, the pinions are intended to drive the racks, rather than to be driven by them.

Three beat indicators, 43, 44, 45, handle the X- axis signal, the signal being fed to the beat indicators in parallel. These indicators may be of any convenient type. They function to provide an output or a failure of output when two signals having a predetermined frequency relation are received. In the present case, they generate an output when the two signals are of the same frequency, and thus may hereafter be referred to as zero beat indicators.

Zero beat indicator 43 is connected to left motor 46, this being a motor turning to the left or otherwise arranged to drive stylus 40 left-wardly, through coupling 41, shaft 48, torque amplifier 49 and pinion 4I. Beat indicator 45 is connected to right motor 50 for driving stylus 40 rightwardly in similar fashion. Indicator 44 is connected to a stop or brake motor 5I, the function of which is to stop one motor, shaft 48 and other related parts, before a newly actuated motor takes control. This operation will be more fully described later.

Three oscillators 55, 56, and 51, of convenient type, with means for varying their frequencies, as variable capacitors 58, 59, 50, respectively, also feed into the zero beat indicators, into 43, 56 into 44, and 51 into 45. The frequency of oscillator 55 is less than that of 56, which, in turn, is less than the frequency of 5l. And these oscillators, unlike oscillators 25 and 30, of Figure l, are so arranged that their frequencies, are variable simultaneously, rather than individually. while These parts, in other words, handle signals covering a different frequency range-that of the Y-axis--than do the parts previously explained.

The apparatus functions in the following manner:

Assume that stylus II, Figure 1, is moved upwardly and to the right from its illustrated position toward point P. The movement will of course produce a displacement of the stylus in the slots I2 and I4 of members I3 and I5, respectively, and will also cause changes in the positions of the latter two members, I3l moving upwardly, and I5, to the right. Since member I3 is secured to rack I6, this rack will move upwardly, and in like manner rack I'I will move rightwardly, thereby causing clockwise rotation of the pinions iB and I9.

As mentioned earlier, these pinions are iinited with the variable condensers 3l and 26, and it will be assumed that this linkage is such that clockwise rotation of pinions I8 and iii decreases the capacities of condensers 3l and and thus increases the frequencies of oscillators t9 25.

After modulation, the combined X-axis and SZ-axis signal is transmitted in whatever fashion the circumstances demand.

Upon reception, the X-axis signal is introduced to zero beat indicators d3, se and l5 in parallel, and the Y-aXis signal, to Zero beat indicators B5, 6&5 and B1. Considering the X-aXis signal, it will be understood that oscillators 55, 55 and 5l are also feeding into the zero beat indicators 43, 44 and t5, respectively.

At some predetermined point, the incoming X-aXis signal and the signal generated by oscillator B will have the same frequency, and Zero beat indicator i5 will be activated. Then, as the stylus il is moved to the right, the X-aXis signal will increase in frequency and reach the frequency of the output of oscillator 5l, zero beat indicator i5 will be activated, and right motor 5l) will be started. Motor operating through coupling lll, shaft 38, and amplifier lit, drives pinion 4I clockwise, and the pinion in turn moves its cooperating rack rightwardiy, thereby driving stylus 4B in the same direction.

While stylus il continues its rightward movement, the capacity of condenser i@ i progressively reduced, and thus the frequency of oscillator continues to rise. This increasingly fast signal is nevertheless kept synchronized, after reception, with the output of oscillator 5l by means of the mechanical connection between pinion 4l and the ganged condensers 58, 59 and 6U.

When stylus il stops, however, the frequency of the oscillator associated with it will become constant. Disregarding a very small fraction of a second of lag between the stylus ii and stylus d, the frequency of oscillator will then be the same as that of the incoming X-axis signal, zero beat indicator 44 will be actuated, and stop motor 5I will take control. In a similar manner,

la leftward movement of stylus II causes left motor le to take control from motor 5I.

The operation of the Y-axis system is in all respects the same as that of the X-axis system, just described. Working in conjunction, the two systems provide for stylus @D a resulting action substantially duplicative of the movement of stylus Il.

It will be understood, of course, that the invention is not limited to the transmission of intelligence according to a system of rectangular coordinates. Under certain conditions, the written or printed message may be one-dimensional in nature; on the other hand, spherical, cubical,

(lll

and polar coordinates may be employed.

It should be understood further that many changes can be made in the forms and proportions of the various parts of the apparatus shown and described without departing from the spirt ci the invention. For the true scope of the invention, therefore, reference should be had to the appended claims.

The invention having been described, what is claimed is:

in for producing a representation al of varying frequency, said apparatus g a device for making the representation, lor actuating the device comprising a for morir the device in one direction, second motor for moving the device in another H in, controlling means governing the acation of motors comprising a beat inl. each motor means for applying the simultaneously to said beat indicators, an oscillator for each beat indicator, the norinai frequencies of the oscillators varying each from the other, means dependent upon movement of the device for varying simultaneously the frequencies of the oscillators, and means dependent upon a predetermined beat condition in said indicators for selectively actuating said motors.

2. The combination of a movable device for producing a pattern to be transmitted, an oscillator, means for increasing the frequency of the oscillator upon movement of the device in one direction and for decreasing its frequency upon movement in another direction, means for transmitting the output of said oscillator, receiving and reproducing means including a stylus or the like, a second oscillator having a normal frequency adapted to be increased upon movement of the stylus in one direction and decreased upon movement of the stylus in another direction, a third oscillator having a normal frequency different from that of the second oscillator and adapted to have its frequency likewise increased and decreased upon movement of the writing device while maintaining between the two last mentioned oscillators the frequency diiference mentioned, and means responsive to an increase in the frequency of the rst mentioned oscillator for driving the stylus in one direction and responsive to a decrease in the said frequency for driving the stylus in another direction.

3. The combination of a stylus for producing a pattern to be transmitted, the stylus being adapted to move along at least two axes, an oscillator, means dependent upon movement of the Stylus along one axis for varying the frequency of the oscillator, a second oscillator, means dependent upon movement of the stylus along another axis for varying the frequency of the second oscillator, a modulator for the outputs of the oscillators, and means for transmitting the output of said modulator, receiving and reproducing means including a second stylus adapted to move along at least two axes, a first motor for driving the second stylus in one direction along one axis, a second motor for driving the second stylus in the opposite direction along said axis, a brake or the like for stopping one motor before the other motor takes control, controlling means governing the actuation of said motors and the brake, said controlling means comprising a beat indicator for each motor and for the brake adapted to have the output of the modulator applied in parallel thereto, an oscillator for each beat indicator, the normal frequencies of the last mentioned oscillators Varying each from the others, means dependent upon movement of the second stylus along an axis for varying simultaneously the frequencies of said last mentioned oscillators, and means dependent upon a predetermined beat condition in said indicators for selectively actuating the motors.

4. The combination of claim 3, further characterized by a third motor for driving the second stylus in one direction along another axis, a fourth motor for driving the second stylus in the opposite direction along said other axis, a brake or the like for stopping one of said third and fourth motors before the other takes control, controlling means governing the actuation of said motors, the said controlling means comprising 30 6 a beat indicator for each motor and for the brake adapted to have the output of the modulator applied in parallel thereto, an oscillator for each beat indicator, the normal frequencies of the last i-.ientioned oscillators varying each from the others, means dependent upon movement of the second stylus along the other axis for Varying simultaneously the frequencies of said last mentioned oscillators, and means dependent upon a predetermined beat condition in said indicators for selectively actua-ting the third and fourth motors.

LEO ROSEN.

REFERENCES CTEB The following references are of record in the file of this patent:

UNITED STATES PATENTS iiurnber Nar-ne Date 2,094,668 Harrison Sept. 28, 1937 2,186,252 Little Jan. 9, 1940 2,274,638 Rosene Mar. 3, 1942 FOREZGN PATENTS amber Country Date 521,710 Great Britain May 29, 1945 638,442 France May 24, 1928

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