US2422398A

US2422398A - Recorder and reproducer for spiral photographic disk sound records

Info

Publication number: US2422398A
Application number: US508838A
Authority: US
Inventors: Jr James J Dilks
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-11-03
Filing date: 1943-11-03
Publication date: 1947-06-17
Anticipated expiration: 1964-06-17

Description

June 17, 1947. J. J. DlLKS, JR 2,422,393

RECORDER AND REPRODUCER FOR SPIRAL PHOTOGRAPHIC DISK SOUND RECORDS Filed Nov. 5, 1943 10 Sheets-Sheet l INVENTOR: J

ATTORNEYS.

June 17, 1947. J J; D K JR 2,422,398 I I0 'DI\SK SOUND RECORDS RECORDER AND REPRODUCER FOR SPIRAL PHOTOGRAPH Filed Nov. 5, 1943 10 Sheds-Sheet z INV ENTOR: James fir J14,

ATTORNEYS.

p mm EEEIIIIVAIIII lllllllllllllllll June 17, 1947. J, DIL'KS, J 2,422,398

RECORDER AND REPRODUCER FOR SPIRAL PHOTOG RAPHIC DISK SOUND RECORDS F le Nov- 5, 1943 10 Sheets-Sheet 4 E! 6i ZZZ I N VEN TOR:

W 1 TN ESSES ATxR /EYS.

June 17, 1947'. J. J. 01:13, JR

RECORDER AND REPRODUGER FOR SPIRAL PHOTOGRAPHIC DISK SOUND RECORD-S 1Q Sheets-Sheet 5 Filed Nov. 3, 1943 a NF W 7 E @N mm y i a E Q A N k .5: M N. M aw kw W m MN N: %R

INVENTOR- James J Di Has- 0k, Y 3 P Q ATTORNEYS June 17, 1947. J, MKS, R I 2,422,398

RECORDER AND REPRODUCER FOR SPIRAL PHOTOGRAPHIG DISK SOUND RECORDS Filed Nov. 5, 1945- 10 sheetssneet e WITNESSES:

5a Jam 1 D J72, W x M a g V v v ATTORNEYS.

June 17, 1947. DILKS, J 2,422,398

RECORDER AND REPRODUCER FOR SPIRAL PEOTOGRAPHIC DISK SOUND RECORDS Filed Nov. 5, 1945 10 Sheets-Sheet 7 iiii W1 TNESSES:

\ INVENTOR;

James J Dilks, J14,

A TTORNEYS.

June 17, 1947. J. J. DXLKS, JR 2,422,398 RECORDER AND REPRODUCER FOR SPIRAL PHOTOGRAPEIC DISK SOUND RECORDS Filed Nbv. 5, 1945 10 sheets-511 a 8 MILWDPHOIVE 160 RECORD/N6 AMPL/F/ER INVENTOR:

WI TN ESSES:

Z/ulaj 4 jaFm-flsllfilks, J11,

BY W P Mm I ATTORNEYS.

June 17, 1947. JQJ. DlLKS, JR 2,422,398

RODUCER FOR SPIRAL PHOTOGRAPHIC DISK SOUND RECORDS 1o Sheets-Shet 9 lam;

- RECORDER AND REP Filed Nov. 5, 1943 i I 157 gsmus METHOD \xxi'wmmm WWWW BY iZSEZZJZ JK, 7

WWW ATTORNEYS June 17, 1947. J J; K JR 2,422,398

1 RECORDER AND REPRODUCER FOR SPIRAL PHOTOGRAPHIC DISK SOUND RECORDS Filed Nov. 3, 19 10 Sheets-Sheei 1o .FZG m1 6 HaJXzP:

DWITNESSES': Y INVENTOR; Z/Ma/M 4 Z! 5 r By "1 "1 ATTORNEYS.

Patented June 17, 1947 UNITED STATES PATENT OFFICE RECORDER AND REPRODUCER FOR SPIRAL PHOTOGRAPHIC DISK SOUND RECORDS James J. Dilks, Jr., Haddon Heights, N. J.

Application November 3, 1943, Serial No. 508,838

13 Claims.

This invention relates to sound recording methods and apparatus, and it has reference more particularly to methods and apparatus for recording sound photographically n sensitized film.

The chief aim of this invention is to enable sound to be recorded with absolute fidelity on photographic film either as a laterally undulating line track, a track of uniform density and varying width, or a track of uniform width and varying density.

The first mentioned variety of sound track is produced as hereinafter more fully disclosed, by moving sensitized film past an opening through which a small surface area of the film is exposed, causing a thin pencil beam of concentrated light to be oscillated laterally in accordance with the sound which is to be recorded, and by causing the beam to impinge upon the moving film surface within the confines of the exposure opening. The second variety of sound track is obtained by causing a restricted beam of slender triangular crosssection to be vibrated laterally in the direction of its cross-section and in the direction of a narrow chink of uniform width through which the surface of the moving film is exposed; and the third variety of sound track is created by employing a narrow recording beam of uniform width and elongate section to be vibrated laterally of a correspondingly shaped chink through which the surface of the movin film is exposed.

Another aim of this invention is to render possible the production of spiral sound tracks characterized as above stated on a sensitized film disk, This latter objective is attained, as hereinafter more fully set forth, by rotating the film disk and by concurrently moving an element which provides the exposure opening, as well as the recording beam, radially of said disk.

In connection with apparatus for making sound records under the above principles, it is a still further aim of this invention to provide means whereby the rotative movement of the film disk is varied compensatively with the changing radius of the sound spiral so that a uniform speed is determined for the disk surface linearly of the spiral.

Another object is to incorporat in sound recording apparatus having the foregoing attributes, means whereby the rate of movement of the exposure aperture and the light beam may be changed relative to the rate of rotation of the film disk to alter the pitch (convolution spacing) of the spiral sound track.

A further object of this invention is to provide indicating means from which the extent to which the recording has progressed at anytime durin 2 the operative cycle of the apparatus can be ascertained.

Other aims and objects, with attendant advantages, will appear from the following detailed description of the accompanying drawings.

Fig. I is a top plan view of a sound recording apparatus conveniently embodying this invention.

Fig. II is a longitudinal section of the apparatus taken as indicated by the arrows II-II in Fig. I.

Fig. III is a cross-section taken as indicated by the arrows III-III in Fig. I.

Fig. IV is a horizontal section taken as indicated by the arrowsIV-IV in Fig. II.

Fig. V is a fragmentary section on a larger scale, taken as indicated by the arrows VV in Fig. I.

Fig. VI is a fragmentary section, likewise drawn to a larger scale and taken as indicated by the arrows VI-VI in Fig. I. I

Fig. VII is a detail section taken as indicated by the arrows VII -VII in Fig. VI.

Fig. VIII is a fragmentary detail section, taken as indicated by the arrows VIIIVIII in Fig. V,

showing the drive mechanism of the apparatus.

Fig. IX is a horizontal section of the. drive mechanism, taken as indicated by the arrows IX-IX in Fig. VIII.

Fig. X (sheet 5) is a detail section taken as indicated by the arrows X-X in Fig. V and showing the clutch ,means associated with the drive mechanism.

Fig. XI is a wiring diagram of the apparatus.

Figs. XII, XIII and XIV, are detail views illustrating various types of light beam shaping elements, capable of interchangeable use inthe apparatus, for producing the correspondingly different forms of sound wave recordings respectively shown in Figs. XV, XVI and XVII.

Fig. XVIII is a detail section, taken as indicated by the arrows XVIIIXVIII in Fig. I, showing the set-up employed to produce the wave form of sound recording featured in Fig. XV.

Fig. XIX is a fragmentary detail sectional view, taken as indicated at XIXXIX in Fig. XVIII.

Figs. XX and XXI are views, corresponding to Figs. XVIII and XIX, showing the set-up employed in producing the form of recording featured in Fig. XVI.

Fig. XXII is a vertical section onthe plane XXI-XXII in Fig. II. V

Fig. XXIII is a fragmentary view, correspond- .ing' to a portion of Fig. I, showing an alternative phragm 4 depressed somewhat below its top edge 7 to provide a shallow recess 5. Slidingly engaging the rods 2 above the frame 3 is anupper frame 6 of corresponding configuration having a perimetric flange 1 upstanding from a horizontal web portion 8. To the underside of the frame 6 is secured a gasket 9 of felt or the like, which, when said frame is lowered, is adapted to seal against the top edge of the frame 3. The frames3 and 6 thus jointly form a shallow. light-occluding enclosure for reception of a sensitized film disk D of Celluloid or the like upon which the sound is photographically recorded as later on explained.

For the purpose of raising and lowering the upper or cover frame 6, there is provided means including a, horizontal operating shaft l (Figs. II and III) with a hand-wheel II at one end thereof, said shaft extending longitudinally of the apparatus and being journaled in bearings l2 at the lower ends of brackets I3 secured to, and pendant centrally of, the opposite ends of the frame 3. The brackets l3 also include bearings l5 for the lower ends'of vertical shafts l6 with screw threaded portions engaging axially into internally tapped sleeves l'l. sleeves l I extend upward through guide openings in the frame 3 and contact withthe bottom face of the cover frame 6. At its lower end, each sleeve I1 embodies a polygonal head l8, one side face whereof slidably engages the inner side of the confronting bracket l3 and thus prevents said sleeve from rotating with the coacting screw shaft I6. As shown in Fig. II, the screw shafts iii are driven by the operating shaft Ill through the 'medium of miter gear-couples respectively designated I9. Accordingly, rotation of the operating shaft It in one direction will, through the screw shafts I 6 and sleeves H, be attended by elevation of the cover frame 6 above the frame 3,

to the position shown in Fig.III, for convenience in placing and removing the film disk D; while rotation of said operating shaft in the opposite direction will result in lowerin said cover frame 6 to the normal position illustrated in Fig. II.

Centrallymounted on the diaphragm .4 of the frame 3 is a plate with an annular recess 2|, Fig. V, in its top occupied by a turn-table 22 for the film disk D. The turn-table 22 has an upward axial boss 23 and two upstanding eccentricallyarranged stud projections 23, of different diameters adapted to fit correspondingly-allocated openings 24, 25'v in the film disk D, best shown in 'Fig. XXIV, and thus determine a definite position for said disk. The turn-table 22 also has a depending axial boss 26 which projects through aligned openings respectively in the diaphragm 4 of the frame 3 and in a reinforcing bar 21 extending crosswise of said frame. As shown in Fig. V, the turn-table 22 has afkey couplingcunnection 28 with the upper end of the shaft 29 of an induction motor which is generally designated 30 and is enclosed in a protective housing 3|, the frame 32 of said inotor and the housing 3! being firmly secured to the bar 21.

The induction motor 30 is generally of the type As shown, the

ordinarily employed in phonographs, comprising a disk rotor 33 which revolves in the gap between pairs of

electromagnets

34, 35, respectively supported at opposite sides of the motor frame 32, see Fig. VIII. The speed of the motor 30 is controlled by a fly-ball governor 36 which is mounted on a shaft 3? and driven by a worm 38 and a worm wheel 33 from the motor shaft 29. Asthe gov ernor 36 expands, a'disk 40 connected to the flyball arms 4! reacts upon a finger 42 pivoted at 3 to the motor frame 32, see Fig. IX. Integral with the finger 42 is an arm 35 which has a ball-' joint connection 46 with one end of a link 4?, see Figs. VIII and IX, whereof the other end is connected to an adjustable crank member 48 secured by a screw 49 to a gear sector 53; The gear sector 50 is fulcrumed on a stud 5i projecting from one side of the motor frame 32 and, as shown in Fig. VIII, meshes with a gear pinion 52 on another shaft 53 which is journaled at one end in said frame and, at the other end, to a bearing bracket 56 secured to the frame 3, see Fig. V. The shaft 53 is axially shiftable outward to an extent limited, through engagement of a collar thereon with the bearing bracket 54, by pull upon a finger knob 55 at its outer end. By means of a helical spring 51 in compression between the pinion 52 and asupplemental bearing plate 58 attached to the motor frame 32, the shaft 53 is normally maintained in the position shown in Figs. V and X, with clutch teeth 59 on said pinion engaged with clutch teeth 6!] on the hub of a' spur gear 6! on a short tubular-shaft 62 axially aligned with the shaft 53 and journaled in the motor frame 32. The gear wheel 3| in turn meshes with a pinion 53 on another shaft 64 journa-led in the motor frame 32, the latter shaft also carrying a worm 65 which is driven by a worm whee1'66 on the motor shaft 29. By'the speed-reducing gear connections justdescribed, the sector 50 is slowly moved counterclockwise in Fig. VIII, and through the finger 42 actuated from said sector, the restraint imposed upon the governor 36is gradually increased with attendant gradual increase in the speed of the motor 30 for a purpose which will be fully explained later on.

The movement of the sector 50 is limited in one direction through engagement thereof with a fixed stop 31, see Fig. VIII.

The optical, equipment of the apparatus is all mounted on a carriage l0 (see Figs. IIII,- V and VI) with grooved rollers H at the ends of transverse parallel axles 12 engaging vertically spaced pairs of parallel track rods 73 which extend longitudinally of the cover frame 6. The rodsis have their ends fixed in keepers 13a attached to the'perimetric flange 1 of said frame, see Fig.1. The carriage m is moved along the rails 13 by means of a screw spindle I l journaled at its inner end in abearing l5 centrally of a reinforcing cross bar 16 in the cover frame 5, and at its outer end in the 'perimetric flange 'i of said frame. Resting by gravity upon the screw spindle N is a weighted block I! in the form of a half-nut with internal threads in engagement with the threads of said spindle. As shown the nut-block TI is connected to, a yoke whereof the side arms 73 are pivoted on one of the roller axles 32 of the carriage 10, so as to be'swingable upwardly out of engagement with the screw spindle it of a short vertical shaft 82. I This shaft 82 revolves freely within a sleeve 83 which is axially aligned with the motor shaft 29, and. which extends down through a bearing 84 centrally of the cross-bar 16 of the cover frame 6.

Secured to or integrally formed with the sleeve 83, at the bottom, is a disk 85 which has recesses 36, 81' and 88 to respectively receive the upper boss 23 and the

upstanding projections

24, 25 of the turn-table 22 so that it may coact with said turn-table as a clamp to hold the film disk D in place upon lowering of the cover frame 5, as shown in Fig, V. Afilxed to the short shaft 82 and miter gear 8i is a spur gear 89 which is driven by an intermeshing pinion 98 on a sleeve 8i, secured by a set-screw 92 to a vertical countershaft 93. From Fig. V, it will be further noted that the countershaft 93 is journaled at its lower end in the cross-bar i6, and at its upper end in a bridge piece 84 supported at the top of a pair of uprights 95 on said bar. To the countershaft 93 is also secured a spur gear 96 which is in turn driven by an intermeshing pinion 91 at the top end of the sleeve 83 carrying the film clamping plate 85. By this arrangement, it will be apparent that the screw spindle 14 will be actuated from the motor shaft 29 at reduced speed to shift the carriage 18 along its rails 13 during rotation of the film disk D. The purpose of this carriage movement will also be fully explained later.

In order that the speed of the screw spindle 14 relative to the speed of the turn-table 22 may be changed, the sleeve 9| is provided with an additional gear wheel 98 which lies below the plane of another gear 99 on the short shaft 82. By loosening the set-screw 82 and shifting the sleeve 9| upward on the countershaft 83, the gear 98 may be meshed with the gear 99 with attendant unmeshing of the gear pinion 98 from the gear wheel 89. The reason for the two different speeds of the screw spindle 14 will also be set forth later.

The optical equipment hereinbefore mentioned includes a source of light in the form of a highpowered incandescent bulb I88 which is enclosed within a housing I8I. As shown in Figs, I and VI, the lamp-housing IN is supported by a bridge bar I82 which is secured, with capacity for ad justment, to the roller axles 12 of the carriage 18. Adjustable endwise in a lateral tubular boss i83 of the light housing I8I is a barrel I84 fitted with a pair of lenses I85 by which the light emanating from the bulb I88 is condensed and projected into a prism I86 having a mirrored reflecting surface I81. As shown in Fig. VII, the prism I86 is aflixed centrally of a supporting plate I88 which is vertically adjustable on screw studs I89 upstanding from the circular base II8 of a sleeve III centrally recessed into the carriage 18, the adjustment of the prism being fixable by jam-nuts H2, H3. The light projected into the prism I86 as above explained, is reflected downward into another lens holder II telescopically engaged in the sleeve III which is fitted with a pair of lenses II6 by which the reflected light is further condensed and concentrated. The inner sleeve component II1 of the holder II5 which directly carries the lenses II6 has laterally projecting ears I I8 which are pierced to engage over the screw studs I89, see Fig. VII. Helical springs II9 exert upward pressure upon the ears II8 of the sleeve II1 to keep said ears yieldingly in engagement with adjusting nuts I28 on the screw studs I89. Incorporated with the lens holder H5 is an iris diaphragm conventionally indicated at I2I and which may be adjusted by turning an intermediate knurled sleeve I22 of said holder.

Coaxial with the lens holder H5 is a cylindric block I23 having a circumferential flange at the top which is recessed into the carriage 18 below the flange II8 of the sleeve III. As shown the reduced portion of the block I23 extends down through a longitudinal slot I25 in the plate 8 of the cover frame 6 (see Figs. I, VI, XVIII and XIX), and fixed axially within it by a set screw I26, is an inverted, thimble-like plug I21, having a square aperture I28 in its bottom which is rounded and projects slightly below the block I23. As shown in Fig. VI, the bottom of the block I23 is covered with a soft annular facing I29 of felt, velvet or the like, for light occluding engagement upon the upper face of the film disk D. Within the plug I21 is a circular diaphragm I38 having a square orifice I3I which is somewhat smaller than the aperture I28 in the block I23 and which defines the width of the sound track made on the film disk D. As shown in Fig. XVIII, the diaphragm I38 is fixed against displacement by a sleeve I34 forced into the plug I21.

A pair of overlapping sectoral vanes I35, I36 disposed within a triangular recess I31 in the web 8 prevent entry of light through the slot I25 into the disk film enclosure jointly afforded by the

frames

3 and 6, see Figs. I, II, V and VI. As shown in Figs. I and II, the vanes I35, I36 pivoton a stud I38 and are respectively provided with complementally-arranged diagonalslots I39, I48 through which the pendant portion of the plug I23 on the carriage 18 passes with a snug fit. The vanes I35, I36 also respectively have arcuate slots I4I, I42 concentric with the pivot I38 to clear the sleeve 83 with a snug fit. By virtue of this arrangement, it will be seen that as the carriage 18 is shifted along the track rods 13 toward the axis of the film disk D from the position shown in Fig. I, the vanes I35, I36 will be brought into closer eclipse through camming action between the plug I23 and the diagonal slots I39, I48 and thereby effectively guard the slot I25 at all times. I

The film disk D is kept in firm light-occluding contact with the facing I28 of the plug I21, during the recording, by a presser plate I45 (see Fig. IV) of flexible sheet metal, which, at one end, is secured by a clamp bar I46 to the top of the diaphragm 4 of the frame 3. The free end of the presser plate I45 is covered with padding I41 of felt or velvet to contact the film disk from beneath, see Fig. VI, and. said plate is urged upwardly by a pair of spring wedge members I48. As shown, these wedge members I48 are slotted longitudinally as at I49 for passage of the shanks of securing screws I58 engaging into the diaphragm -4 of the frame 3, so as to be adjustable to vary the pressure.

Also supported by the carriage 18 is a magnetic modulator I5I which may be of any well known design or make, and which is employed for vibrating a light beam by which the sound recording is effected. As shown in Figs, VI and VII, the modulator I5I is'secured to a plate I52 which is apertured to engage over the screw studs I89 hereinbefore referred to, and it is held in position, with capacity for up-or-down adjustment, between pairs of nuts I53, I54 respectively on said studs. Removably attached to the horizontally-vibrating armature I55 of the modulator is a hearing controller in the form of a tongue I56 (Figs, VI, VII and XI) which exa-eaaces 7 r tends transversely pit and intercepts the shaft of light reflected downward .by the prism 101., except for a pencil beam which is permitted to pass through a pinhole (Fig. .XII) therein and enter the lens holder :1 I5 on the carriage 10, as shown :by the vertical .arrowlin Fig. VI.

.In addition to the induction .motor '30, the light bulb I and the modulator II, the electrical equipment used in the apparatus includes :a variable transformer I58 (Fig. XI) for controlling the bulb, a microphone 159, a suitable form of amplifier I60 for intensifying the action of the modulator 1'5 I., and a decibel meter I-BI for indicating the intensity or volume of the sound,

these elements being all suitably wired together as shown in :the diagram and receiving current from a power line I62, 163. A1; IE5 is shown a master switch for starting and at I64 a volume c'oi'itrolknob.

At 166 in Figs. I and 11, there is shown an indicator comprising a dial I61 at the front of .a small housing I68 attached to the perimetric flange 1 of the frame '6 at one side thereof, and a pointer I69 which is secured to a shaft I passing axially through said dial.

By a train I 'of gears *I-II, 412 and I13, I14, the pointer shaft :IIII is driven from the outer end of the screw spindle 14, the gear ratios being such that the pointer I69 makes a complete circuit of the dial I81 for each complete traverse of the carriage 1% By means :of a knob I15, it is possible to re-set the pointer 1-69 to starting position after each-operative cycle of the apparatus. The dial I61 may be graduated to indicate the number of turns made by the turn-table 22 during each recording, or in any other convenient way.

In Fig. XXIII, I have shown an alternative form of gauge means in which a pointer I69a attached to the half-nut 1-1 overtravels a linear scale I61 secured to the top of the web 8 in the frame :6.

Having described the apparatus for carrying out the improved method of sound recording, the Operation thereof is *briefiy as follows:

Preparatory to starting, a blank film disk D is placed upon the turn-table '22- within the enclosure 3., '6, and the carriage 1t moved to the position shown in Figs. I and II; such movement be :ing accomplished by raising the yoke 18, by the knob 19, to disengage the half-nut 11 from the screw spindle M, whereupon the carriage it is pushed. along the track rails 13 until said nut abuts the bearing brackets .15. The switch I65 '(Fig. XI) is next closed with the result that the electric motor and the light bulb 4% are brought into action, with attendant clcsing of the circuit between the microphone I59 and modulator :I5I through the amplifier ISll, and closing of the circuit or circuits containing the volume meter It I. By operation ofthe motor 38, the film disk D jSl-SI OVVJY turned :clockwise, in the direction of the arrow shown :in Figs. I and IV, under control of the fiy-ball governor 36. Due to its connection with the motor shaft 2 8., the .screw spindle 1-4 is coil-currently rotated slowly with the result that the carriage 1?) is moved radially of the film disk D toward the center of the latter; and, :as a result thereof, a sharp spiral line track T will be produced-on said disk bythe pencil light beam projected downwardly through the pin-hole I51 in the tongue I55 and, through the registering aperture I SI of the diaphragm I30, in the plug -I21 on the carriage 10. In responding to'the action of the microphone 159, the modulator I5I causes the tongue I56 'to be vibrated horizontally as indicated by the double arrow in Fig. iKVa so that nodes of varying amplitude are formed in the sound track, as shown in FigsVXV andXlX, corresponding in character to the sound waves impressed upon said microphone. As the recording proceeds, the speed of the turn-table 2 2 is gradually accelerated in proportion to the decreasing radius of the sound track T by action of the finger Q2 (Fig'IX) upon the motor governor 36 in the manner hereinbefore explained, so that the speed of travel of the film disk surface past the aperture I3I inthe diaphragm I30 is kept constant with avoidance of any crowding of the undulations in the track which would otherwise result if the speed of the turn-table 22 were uniform. The progress of the recording is shown at all times by the pointer I69 of the indicator I65. A complete circuit of the pointer I69 around the dial I61 indicates that the carriage iii has reached the end of its inward travel, whereupon the switch I65 (Fig. XI) is opened to bring the apparatus to rest. Finally, the film disk D is removed "and a fresh one substituted in its place for the next recording. After each 0perative cycle, the sector 56 is restored to the starting position, shown in Fig. VIII, by grasping the knob 58 and pulling the shaft '53 outward to disconnect the clutch teeth 59, B0, and then turning said shaft counter-clockwiseuntil the sector again contacts the stop '61.

Having thus described my invention, I claim:

1. Sound recording apparatus comprising a mounting for a sensitized film disk; an element with an opening through which a minute area of the disk is exposed; means for producing a shaft of concentrated light; a recording beam controller with a light-restricting aperture; means'responsive to sound vibrations for oscillating the recording beam controller crosswise of the light shaft; and means for rotating the mounting and con currently moving the element aforesaid, the light producing means, the sound vibration responsive means and the recording beam controlled radially of the disk so that a spiral sound track is pro-' duced on the film disk.

2. Sound recording apparatus according to claim 1, including means for gradually varying the rotative movement of the mounting compensatively with changes in the radius of the spiral track to determine a constant speedof the disk surface linearly of said track.

3. Sound recording apparatus comprising a mounting for a sensitized film disk; an element with an opening through which a minute area of the disk is exposed; means for producing a shaft of concentrated light and directing :it toward the exposure opening; a recording beam controller with a light-restricting aperture; means responsive to sound vibrations for vibrating therecording beam controller crosswise of the light shaft;

.a motor for rotating the film. disk mounting;

means for concurrently moving the element aforesaid, the light producing means, the vibrationresponsive means, and the recording beam controller radially of the film disk so as to predetermine production of a spiral sound track 'on said disk; a governor associated with the motor; and means :for automatically controlling the governor to vary the rotative movement of the mounting c'o'mpensatively with the changing radius of the spiral track and thereby determine a uniform speed of the'disk surface linearly of the spiral sound track.

'4. Sound recording apparatus comprising an enclosure; a mounting for a sensitized film disk within the enclosure; means for rotating the mounting; a carriage confined to horizontal travel above the enclosure radially of the film disk; an element with an exposure opening extending from the carriage down through a slot in the top of the enclosure into contact with the disk; means preventing entry of light into the slot; means on the carriage for producing a shaft of light and directing it toward the exposure opening; a recording beam controller with a, lightrestricting aperture; means also on the carriage responsive to sound vibrations for oscillating the recording beam controller crosswise of the light shaft; and mean for moving the carriage concurrently with rotation of the film disk mounting, so that a spiral sound track is produced on said film by the controlled recording light beam.

5. Sound recording apparatus according to claim 4, wherein the means for rotating the film disk mounting include a motor; and wherein an automatic governor varies the speed of the motor compensatively with change in the radius of the spiral sound track produced on the film disk, to determine a constant speed of the disk surface linearly of said sound track.

6. Sound recording apparatus according to clai 4, wherein the carriage is moved by a screw, and means operatively coordinating said screw with the drive means for the disk mounting.

7. Sound recording apparatus according to claim 4, wherein the means for rotating the film disk mounting includes a motor, to the shaft of which said mounting is secured; wherein the carriage is shifted by a screw spindle; and wherein the screw spindle is geared to the motor shaft.

8. Sound recording apparatus according to claim 4, wherein the means for rotating the film disk mounting includes a motor to the shaft of which said mounting is secured; wherein the carriage is shifted by a screw spindle; and wherein the screw spindle is driven from the motor shaft by change speed gearing so that the spacing of the convolution of the spiral sound track produced on said disk may be varied.

9. Sound recording apparatus according to claim 4, wherein the carriage is moved by a screw spindle operated from the drive means for the disk mounting; and wherein the coupling connection between the carriage and the screw spindle includes a half-nut, and a supporting-arm for the nut pivotally connected to the carriage, so that said nut can be disengaged from the spindle to permit return of said carriage to starting position, at the termination of an operative cycle of the apparatus.

10. Sound recording apparatus according to claim 4, further characterized by an indicator to show the progress of the recording, and means operativel'y coordinating said indicator for movement by the carriage.

11. Sound recording apparatus according to claim 4, wherein the enclosure includes a fixed bottom component and a cover component; lifting means for the cover component include a plurality of vertical screw shafts; internally threaded sleeves hold against rotation with the screws and engage the cover component from below; .an operating shaft; and gearing whereby the screw shafts are concurrently rotated by the operating shaft.

2. Sound recording apparatus according to claim 4, wherein the enclosure includes a fixed bottom component and a liftable cover component; the disk mounting is journaled in the bottom component; the carriage and the means for moving it are supported by the cover component; and wherein the carriage moving means includes a plate which is journaled in the cover component, said plate being adapted to bear downwardly upon the film disk and to openatively couple the carriage moving means with the disk mounting.

13. Sound recording apparatus according to claim 4, wherein the enclosure includes a fixed bottom component and a liftable cover component; the disk mounting is journaled in the bottom component and provided with eccentrically arranged studs for engagement in correspondingly-allocated openings in the fihn disk; the carriage and the means for moving it are supported by the cover component; the carriage moving means includes a plate which is journaled in the cover component, said plate being adapted to bear downwardly on the fihn disk, and openings in the plate wherein studs on the disk mounting are received to operatively coupl the carriage moving means with said mounting.

JAMES J. DILKS, JR.

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

UNITED STATES PATENTS Number Name Date 1,894,373 Kahn Jan. 17, 1933 1,853,812 Hewlett Apr. 12, 1932 2,097,141 Blaney Oct. 26, 1937 1,857,569 Poulsen May 10, 1932 1,641,947 Scully Sept. 6, 1927 1,925,919 Drew Sept. 5, 1933 2,124,030 Douden July 19, 1938 FOREIGN PATENTS Number Country Date 431,625 Great Britain 1935