US2672394A - Multiple styli recorder - Google Patents

Description

March 16, 1954 Filed June 12. 1945 'F. A. JESWINE ET AL MULTIPLE STYLI RECORDER 2 Sheets-Sheet. 1

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FRED A. JESWINE KENNETH K.WYCKOFF MALCOLM c. |-|ENoERsoN March 1954 F. A. JESWINE ET AL MULTIPLE STYLI RECORDER Filed June 12, 1945 2 Sheets-Sheet 2 FREDA. JESWINE :m M F om D N YE WH 7 K C H TWL mm M MW w Patented Mar. 16, 1954 MULTIPLE STYLI RECORDER Fred A. Jeswine, Malcolm C. Henderson, and Kenneth K. Wyckofl, San Diego, Galif.,assign to the United States of America as representedby the Secretary of the Navy Application June 12, 1945, Serial No. 599,110

Claims.

.1 This invention relates to recorders and more particularly to a type of recorder which may be utilized to portray information received by the kind of echo-ranging system disclosed in a copendingapplication entitled Echo-Ranging System, Serial No. 520.667, filed February 1, 1944, by Charles A. Hisserich.

The echo-ranging gear illustrated in the above mentioned application one utilisinga continuous signal, frequency modulated with a linear sawtooth wave. In this manner, heterodyning of the transmitted wave with the returning echo waveproducesan output which may contain several beatfrequencies, each of which is indicative of .:a target at'aparticular range. As described in the application mentioned above, this output is applied'to :a. series ofadiacentban'd-pass filters forthe purpose of separating these frequencies and determining the presence of targets in any of the range increments (as represented by the pass-bands of the filters).

The present invention has for one of its objects the simultaneous portrayal of signals in all the respective channels or pass-bands, and thus, atall ranges being observed. Further, an object of the invention is to portray the presence of targets in their proper relative position with respect to the-ship on which the sound gear is mounted. The portrayal is accomplished by moving a sheet of saturated iodide recorder paper between a series of styli and conducting annuli (each of which is fed by the output of one or the filters) in a manner that the passage of electric current between an annulus and its corresponding stylus, and through the paper, causes a darkening of the paper.

In the drawings:

Fig. 1 is a perspective view of one form of the invention.

' Fig. 2 is a plan view of the carriage with the guard ring removed.

Pig. 3 is a partial sectional view along the line 3-3 of Fig. 2.

Fig.4 is a partial sectional view along the line 4-4 of Fig. 2.

Fig. 5 is a schematic diagram of the electrical circuit used with the recorder.

The recorder comprises, in essence, as is shown inFig. 1;a light-proof, air-tight, paper magazine I, a hat base plate! across which the paper emergingfrom the. magazine is driven, a circular, rotating carriages to which is'fiXed the stylus mount:4, and mechanisms for driving the paper and-carriage.

".S'I'he base plate 2 is supportedin'position by a pair of side members 5 to which it may be secured by screws, bolts or other convenient'means. This base plate is provided, at its center and just under the rotating carriage 3, with a non -con ducting circular insert 1, as shown in Figs. 1, 3 and 4. This may be conveniently formed or Bakelite or some other sturdy material. The upper surface of this insert is provided with a series of concentric, metallic, conducting annuli 8, 8, 8 in a number equal to the number of filter channels whose output it is desired to record. These annuli, as can be seen in Fig. 3, are formed by machining a series of slots into the insert 7, into which copper or other suitable metal is sprayed or poured, the upper surface of which is machined off to provide a smooth surface. These slots do not extend entirely through the plate, as can be seen in Fig. 3. At a convenient point on the under side of the insert, a radial groove is machined, as at 9, Figs. 3 and 4. A series of small metal pins H), I0, ill" one for each annulus, is positioned in the insert to extend from the annuli, through the non"- conducting insert, into the groove at 9 for convenient electrical connection to the filters.

At the end opposite the magazine I, the side members 5, 6 support a pair of driving rollers H, l2 between which the paper It passes. These are formed of some soft material such as rubber to engage the paper and pull it over and across the base plate 2 and the conducting annuli 8, 8, 8", These rollers I I, l2 are mounted very closely adjacent one another whereby the paper is held tightly between them. Below this pair of driving rollers is another roller [4 to receive and store the marked paper. These rollers may be mounted in side members 5, '6 by any convenient means and rollers l2, M are provided with pulleys l5, it at one of their ends (and outwardly of the side member). A small motor I! is also mounted on the side member 5 in a position convenient to drive rollers l2, M by means of a pulley I5 (mounted on the motors shaft) and belt or chain 19. The motor I! is of the variable speed type for a purpose to be described below and thus may draw the paper across the base plate and under the rotating carriage at any desired speed.

The carriage 3 is provided with a conventional hinge assembly 20 bolted to main base plated-5 in order that the carriage may be lifted away from plate 2 to facilitate insertion of paper 13. *At its opposite edge, it carries a lifting handle 21 and a conventional locking mechanism 22 may be u'sed'to hold it in place.

The carriage comprises a heavy metal retaining ring 23 within which is mounted a rotating race 24. These parts are grooved at their adjacent sides to provide for bearings 26 which permit the race to rotate within the retaining ring, as shown in Fig. 3. As can be seen, the race 24 is formed of an upper and lower section to facilitate insertion of the ball bearings 26.

The race is also provided with a small inwardly extending flange 21 which supports a circular plate 28 of some transparent material such as Lucite. This plate is held in position by means of a thin retaining band 23 conveniently attached to the inner side of the race 24. A ring gear 30 is attached to the upper surface of the race by means of bolts 60 (which also extend through and hold the parts of the race together). The ring gear in turn supports an insulating guard ring 3| on its upper surface which maybe attached by bolts or screws. A conducting slip-ring 32 is secured to the upper surface of the guard ring and this slip-ring is engaged at one point by a brush 33. The brush may be secured to a stationary portion of the recorder by means of a bracket 34 which, as shown in Fig. 3 is attached to the hinge assembly 20. A short conductor 35 is arranged to provide electrical contact between the slip-ring 32 and the stylus mount 4 and rotates with the race.

Rotation of the race 24 and the stylus mount 4 is accomplished by means of a small Selsyn motor 38 conveniently mounted on side support 49 as seen in Fig. 1. The motor is designed to drive a short shaft 31 on the end of which a small drive gear 38 is mounted. This gear engages the ring gear 30 to drive the race 24 and the stylus mount 4. The motor 36 is preferably a Selsyn follower and is arranged to receive its power from a source to be described.

The stylus mount 4 is supported by the transparent insulating plate 28 and is shown in detail in Fig. 4. It comprises a pair of conducting strips 39, 40 (of a material such as brass) mounted radially of plate 28. Each of the strips is provided with a flange 4| and they are bolted together through the flanges and to the plate 28 by means of bolts 42. The lower strip 39 and the plate 28 are drilled with a series of aligned holes and each receives one of a series of contact styli 43, 43', 43". These styli are positioned and spaced so as to lie directly above the series of annuli 8, 8', 8" in insert 1 over which they lie, in a manner that as rotation of the race and the styli mount 4 takes place, each stylus 43 moves in a circular path and remains directly above its corresponding annulus 8.

Since, as can be seen in Fig. 4, the paper |3 is designed to pass between the extending ends of the styli 43 and the annuli 8, means for adjusting the force with which each stylus bears on the paper is provided by means of a combshaped spring 44 better shown in Fig. 1, positioned between the flanges 4| of strips 39, 40. In addition, each stylus 43 carries a small coil spring 45 around its shaft and which bears against the underside of its head and plate 28. One tooth of the comb-shaped spring 44 is arranged to bear on the head of each one of the styli and the combination of springs thus provides restraint against motion of the stylus in either direction. The amount of this restraint on each stylus may be individually adjusted by means of a series of adjusting screws 46 which bear directly on the teeth of spring 44 and are correspondingly positioned above the styli in flange 4| of strip 40. The styli are commonly connected to the electrical conductor 35 through a series of contact strips 41 (Fig. 3) secured to the heads of the styli, as by welding or silversoldering.

The magazine l which holds the paper I3 is formed with a light gate 48 (see Fig. 1) which may be of a type used in conventional fllm magazines and which prevents light from reaching the paper until it is unrolled. The paper itself is stored on a roll within the magazine and its mount may be provided with spring or other means within the magazine to maintain the paper suitably taut as it is pulled across the base plate 2 between the annuli and the styli 43 by means of the rollers I2.

The electrical circuit for use in conjunction with the recorder is shown in the schematic diagram of Fig. 5. The drawing illustrates only one channel of the recorder, but each of the other channels is identical with the one shown. The output of one of the band-pass filter-rectifler combinations of the application referred to above (and as shown in Fig. 5 thereof) isapplied to the grid of a cathode follower tube 50 (which may conveniently be a 6J5 or of a 6SN7). The tube is provided with a conventional cathode resistor 5| and is fed from power supply 52. An adjustable potentiometer 53 is provided across the power supply and its adjustable tap is connected to the stylus 43 (through the brush 33, slip ring 32 and conductor 35 described above). I nected to the corresponding annulus 8 and the contact between the stylus and annulus, through the recording paper, thus completes the circuit. The power supply is arranged to supply 300 volts and the tap on the potentiometer 53 is arranged to take oil a voltage in the neighborhood of 5 to 45 volts, depending upon the threshold conditions of the paper used.

Additionally, as has been heretofore suggested, the Selsyn motor 36 receives its power from another driving Selsyn (not shown) which lat.- ter motor is directly connected to the shaft which rotates the wave receiver or receiving transducer of the echo-ranging gear (see Fig. 5 of the above mentioned application). It is clear that by thus choosing the proper gear ratios, the ring gear 30 may be caused to rotate the carriage 3 and stylus mount 4 in synchronism with the receiving' transducer of the echo-ranging gear.

In practice, the various filter channels (which represent range or distance bands in the transmitting medium) are connected to and associated with the conducting annuli 8 on the recorder in a manner that the lowest frequency band (representing the closest distance increment scanned by the echo-ranging gear) is connected to the annulus with the smallest radius and the others increase proportionately outward. A voltage appearing in any one of the filter circuit outputs is thus applied to the respective annulus and stylus and the resulting current flow darkens the paper therebetween.

If the orientation of the stylus mount 4 is now adjusted to correspond to a relative bearing on the ship on which the gear is mounted, and the carriage is rotated in synchronism with the receiving transducer, the presence of a target at any range and bearing will cause a darkening of the paper in a corresponding position, measured from the center of rotation of the carriage.

In operation, if the echo-ranging gear is fixed and does not move-the receiving transducer The cathode of tube 5|) is con- I rotates, scanning the surrounding area. In this case, the motor I I is not operating and the paper is held stationary. Since, by means of the Selsyn system, the carriage 3 and stylus mount 4 rotate in synchronism with the receiving transducer, any signals supplied by the filters produce darkening of the paper in a corresponding position, as described. However, since most gear is utilized on a moving ship, the means (including the motor I l and rollers ll, l2) for moving the paper l3 allow this movement to be portrayed. In this situation, the direction opposite the paper movement is assumed to be the direction of motion of the ship and the paper moving under the carriage corresponds to this ship movement. The speed of the motor I! is determined in a manner that the paper speed equals the speed of the ship on a scale corresponding to the spacing of the styli (as these represent, through their spacing and their relation to the filter pass-bands, range increments). In effect then, the paper moving under the carriage and stylus mount may be considered the movement (so to speak) of the ocean under the ship and the portrayal of a target by blackening of the paper will be in the form of a trace of its movements, if any, in the water. If it has no movement, it will appear as a single dark spot, although the darkening will possibly be produced by more than one stylus at different times.

For example, if a stationary target be assumed dead ahead of the ship, and the range is closing, it will first appear as a darkened spot produced under the outermost stylus. As the range decreases, the echo signal appears in other channels, but as the scale of motion of the paper and the spacing of the styli has been properly chosen, the appearance of the signal in other channels will only cause darkening on the same spot on the paper, as the paper will have moved toward the styli corresponding to shorter ranges. In the same manner it can be shown that if the target is movin the blackening of the paper, as current flows in the various channels, will take the form of a trace of the targets movement.

Having described the invention, we claim:

1. A. recorder for use with an echo-ranging system of the type which distributes the echo signals from a plurality of range increments into corresponding channels, comprising: a plurality of concentric. conducting annuli, positioned in a plane; a plurality of conducting styli mounted closely adjacent to said annuli; means for supporting a sheet of sensitized paper positioned between and in contact with said annuli and said styli; each of said styli being positioned to contact said paper directly opposite a corresponding one of said annuli; means for applying the output of each of the said channels of said system across a corresponding one of such annulus-stylus combinations whereby a signal in said channel will produce an indicative mark on said paper.

2. In the device described in claim 1, means for rotating said plurality of conducting styli in a plane parallel to the plane of said annuli about an axis passing through the center of said annuli.

3. In the device described in claim 1, means for rotating said plurality of conducting styli in a plane parallel to the plane of said annuli about an axis passing through the center of said annuli in synchronism with the rotation of the receiving transducer of said system.

4. In the device described in claim 1, means for moving said paper in a given direction past said annuli and said styli at a speed proportional to the speed of the vessel on which said system is mounted.

5. A recorder for use with an echo-ranging system of the type which distributes the echo signals from aplurality of range increments into correspondin channels, comprising: a plurality of concentric, conducting annuli, positioned in a plane; a plurality of conducting styli mounted closely adjacent to said annuli; means for supporting a sheet of sensitized paper positioned between and in contact with said annuli and said styli; each of said styli being positioned to contact said paper directly opposite a corresponding one of said annuli; means for rotating said plurality of conducting styli in a plane parallel to the plane of said annuli about an axis passing through the center of said annuli; means for moving said paper in a given direction past said annuli and said styli; means for applying the output of each of the said channels of said system across a corresponding one of such annulusstylus combinations whereby a signal in said channel will produce an indicative mark on said paper.

FRED A. JESWINE. MALCOLM C. HENDERSON. KENNETH K. WYCKOFF.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 385,042 Chase June 26, 1888 1,094,487 Spalazzi Apr. 28, 1914 1,109,667 Dickeman Sept. 8, 1914 1,211,703 Hess Jan. 9, 1917 1,345,626 ONeil July 6, 1920 1,551,220 Schefiler Aug. 25, 1925 1,649,870 Stoneham Nov. 22, 1927

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