US2225323A

US2225323A - Sound reproducing apparatus

Info

Publication number: US2225323A
Application number: US76568A
Authority: US
Inventors: Victor H Severy
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-04-27
Filing date: 1936-04-27
Publication date: 1940-12-17
Anticipated expiration: 1957-12-17

Description

2 Sheets-Sheet 24 V. H. SEVERY scum) REPRODUCING APPARATUS Original Filed April 27. 1936 fig.

Dec. 17, 1940.

22 w W a a W a w a m wz a J Dec. 17, 1940. v. H. SEVERY 2,225,323

SOUND REPRODUCING APPARATUS Original Filed April 27, 1936- 2 Sheets-Sheet 2 Patented Dec. 17, 1940 UNITE STATES SOUND REPRODUCING APPARATUS Victor H. Severy, Glendale, Calif.

Application April 2'1, 1936, Serial No. "16,568 Renewed May 18, 1940 K 8 Claims. (01. l79100.l)

This invention relates to sound reproducting apparatus and it is a general object of the invention to provide apractical improved and particularly efiective electrostatic sound reproducing apparatus. d

Another object of this invention is to provide an electrostatic sound reproducing apparatus operable to faithfully and accurately reproduce recorded sound programs of various natures.

Another object of this invention is to provide a sound reproducing apparatus embodying an electrostatic pick-up and a record strip alternately moved lengthwise in opposite directions and bearing a multiplicity of sound tracks which successively cooperate with the pick-up, as the record strip alternately travels in opposite directions, to thereby reproduce in succession the programs or sound matter of the individual sound tracks.

Another object of this invention is to provide a sound record for use in reproducing apparatus of the character mentioned above that comprises a band or strip of flexible non-magnetic and nonelectrical conducting niaterial which may be of great length and which bears a plurality of sound tracks of metallic or partially metallic material for influencing an electrostatic pick-up. The novel sound band of the present invention may be of such length that each sound track thereof may individually comprise a complete recording or chapter of a recording, such as a radio program of a given duration, or the sound complement of a reel or motion picture film, or any other sound program.

Another object of this invention is to provide an electrostatic sound reproducing apparatus of the character mentioned that is entirely automatic in its operation, requiring no attention subsequent to its initial conditioning and energizalOIl.

Another object of this invention is to provide a sound reproducing apparatus that automatically moves the elongate sound record in alternate directions and automatically shifts or conditions the electrostatic pick-up to be successively influenced by the sound tracks of the record during successive alternate movements of the record to thereby reproduce the sound material of the individualtracks, there being a minimum time interval between the successive passage of the sound tracks through the pick-up.

Another object of this invention is to provide a sound record for use in apparatus of the character mentioned above that is inexpensive to produce and reproduce and-that is in convenient form for handling, shipping, etc. The record provided by the present invention is in the form of a single continuous strip of flexible sheet material which may be wound upon a suitable reel for convenient handling, shipping, etc..

The various objects and features of my invention will be fully understood from the following detailed description of typical preferred forms and applications of my invention, throughout which description reference is made to the ac-' 1o companying drawings, in which:

Fig. 1 is a vertical detailed sectional view of the apparatus provided by the present invention. Fig. 2 is an enlarged fragmentary vertical detailed sectional view taken as indicated by line 15 2-2 on Fig. 1 and illustrating the pick-up and its control. Fig. 3 is an enlarged fragmentary vertical detailed sectional view of the ratchet and solenoid coil of the pick-up control. Fig. 4 is an enlarged fragmentary detailed sectional view 20 taken as indicated by line 44 on Fig. 2. Fig. 5 is an enlarged fragmentary detailed sectional view illustrating one of the releasable clutches. Fig. 6 is a fragmentary plan elevation of the record being a view taken substantially as indicated 5 by line 6-6 on Fig. 1. Fig. 7 is a fragmentary plan elevation of another form of record and Fig. 8 is a schematic wiring diagram of the circuits involved in the invention.

The present invention provides, generally, an 30 elongate sound record [0 bearing a multiplicity of sound bands or sound tracks ll, means l2'for alternately moving the record f0 longitudinally in opposite directions, an electrostatic pick-up i3 responsive to or influenced by the tracks II and 5 operable to impose current modulations on a loud speaker unit It, means l5 for automatically conditioning the pick-up l3 for successive cooperation with the sound tracks II, and other parts, the details and functions of which will be herein- 40 after described.

The record I0 is an important feature of the invention. The record Ill bears or carries the multiplicity of sound bands or tracks H and owing to the fact that it may be of great length the individual tracks I I may be continuous tracks each constituting a recording of a complete sound program. In accordance with the invention the record I0 is an elongate strip of flexible material. The record In is preferably formed of non-magnetic and non-electrical conducting material, such as paper, fabric, Cellophane or similar sheet material or a combination of such materials. 'the record Ill is preferably of uniform width throughout its length and the length of the record is,

of course, determined by the length of the sound tracks The record It is preferably wound on a reel l6 for'easy handling and for assembly in the apparatus. When employed or threaded in the sound reproducing apparatus the record I is wound from one reel It to a second reel l3 and then wound back on the first reel, and so on.

The reels It may be of suitable or typical construction and may embody hubs l1 and suitable side flanges.- The opposite ends of the sound record I0 are suitably connected or associated with the hubs ll of the reels. In practice tabs or reduced end parts on' the record "I may be inserted in slots in the hubs ll. It is to be understood that the sound reproducing apparatus of the invention is adapted to handle sound records bearing sound tracks ll of different sound programs.

The sound tracks I extend longitudinally of the record In and are transversely spaced one from the other for successive cooperation with the pick-up I3. The tracks alternately extend longitudinally in opposite directions as indicated by the arrows in Fig. 6. It is a feature of the invention that there may be a number of sound tracks II on a single record It. In the,

particular case illustrated in the drawings there are five tracks on the record Ill, it being understood that the invention is not to be construed is' preferably in the nature of a' driven or power as limited to this particular number of sound tracks. The sound tracks may be of the hill and dale or variable area type illustrated in Fig..

a suitable non-magnetic electrical conducting material in a finely divided or colloidal state. The sound tracks Il may be produced photographically, in which case the metallic sliver of the tracks is sufficient to properly influence or afiect the electrostatic pick-up l3. The sound tracks II are preferably equally spaced apart transversely of the record 10 and may have straight base edges l8. The tracks II on the record l0 may be of different lengths. However, in the present instance it will be considered that the tracks are of substantially the same length. The sound tracks H terminate some distance inwardly from the opposite ends of the record ID to permit the proper threading of the record in the apparatus and to insure the cooperation of the complete sound tracks with the pick-up l3.

The means l2 for moving thesound record flfl actuated means controlled to automatically move the record In longitudinally in opposite directions. A suitable structure or frame is provided to carry the means l2 and other parts of the apparatus. In the particular case illustrated in the drawings this frame includes two spaced vertical end members l9 connected by

side members

20 and 2|. A removable or hinged door may be provided on one of the members to give access to the. interior of the apparatus. The means |2 includes two spaced parallelshafts 22. The shafts 22 may be supported by suitable bearings on the member 20 and are substantially horizontal. The shafts 22 are provided to carry the reels I6. Keys 23 or other suitable means may connect the reels It with the shafts 22 to turn therewith. The record moving means |2 includes two spaced drums or pulleys 24. The pulleys 24 are rotatably supported by suitable bearings. 25 on the side member 20. The pulleys 24 are rotatable about horizontal axes and a pulley 24 is spaced above each reel IS. The pulleys 24 are provided with leather or similar material to cooperate with the record It.

A driving or operating motor M is provided for rotating each pulley 24 and the adjacent reel IS. The motors M are preferably synchronous motors. Suitable brackets 23 on the frame members l3 may carry the motors M. The motors M drive the adjacent pulleys 24 through suitable speed reducing and speed governing mechanisms 21 so that the pulleys are rotated at constant speeds to properly move the record I. A driven shaft 28 of each speed reducing mechanism 21 carries a gear 25 which meshes with a gear 30 on the shaft of a pulley 24. The reel shafts 22 are rotated to take upthe record It. Each speed reducing mechanism 21 drives :a shaft 3|. The shafts 3| carry gears 32 which mesh with gears" 33 fixed on shafts 34. The shafts 34 each have a gear 35 meshing with a gear 33 on a reel shaft 22. The reels ||i are rotated at higher rates than the pulleys 24 to properly take up the record It during the first portion of each movement of the record. Suitable friction clutches 31 are interposed in the shafts 3|. The clutches 31 are adapted to slip under increased torque resulting from the increase in the diameter of the record It being wound on the reels It. A positive releasable clutch C is provided between each speed reducing mechanism 21 and the adjacent shaft- 3|. Similar positive releasable clutches C are .provided between each speed mechanism 21 and the adjacent shaft 23.

Fig. of the drawings illustrates a clutch C of a reel drive. It is to be understood that the clutches C in the reel drives and the pulley drives may be identical. The clutch C illustrated in detail in Fig. 5 includes a toothed clutch member 4 33 fixed on a driven shaft 3| of the adjacent speed reducing mechanism 21. A complementary toothed clutch member 39 is shiftably splined on the shaft 3| and is adapted to cooperate with the member 33. A pivoted yoke 40 cooperates with the member 39 to shift the same. The yoke 40 has a projecting arm 4| and a spring 42'is connected with the arm 4| to urge the member 33 into cooperation with the member 33. A solenoid coil 43 is provided to release the shiftable clutch member 39 from the driven clutch memher-38. The armature 44 of thecoil 43 is pivotally and shiftably connected with the arm 4|. When the coil 43 is energized the yoke 40 is pivoted to shift the clutch member 39 out of engagement with the clutch member 38.

The record moving means |2 includes an automatic controlfor effecting alternate energization of the motors M and the alternate energization of the clutch solenoid coils 43 whereby the record In is alternately moved in opposite directions. This automatic control of the means |2 includes a photo-electric cell 45 and an exciting lamp 46 for the cell. The photo-electric cell 45 and the lamp 46 are arrangedat opposite sides of the record It adjacent an edge of the record. The cell 45 and the lamp .46 are preferably positioned in opposite sides of a tensioned web portion of the record I adjacent the pick-up I3. The record I6 carries an opaque or relatively opaque band 41 adjacent one of its edges, which band passes between the cell 45 and its lamp 46. The band 41 preferably terminates some distance beyond the ends of the sound tracks II.

The motors M and the coils 43 of the several clutches C are under the controlof a reversin switch 41 which in turn is under the control of the photo-electric cell 46. Any suitable or conventional type of double reversing switch 41 may be employed in the apparatus. The switch 41 is controlled or thrown by a solenoid coil 48. The energized conductors or leads 49 of the photoelectric cell 0 are connected with the terminals of the coil 48'whereby the coil 48 is energized when an end of the opaque band 41 passes the lamp 46 and the cell 45. The motors M each have an energizing circuit or a pair of leads X extendmg to the switch 41. The solenoid coils 43 of the clutches C have their energizing leads Y connected with the motor energizing leads X. The leads Y governing the coils 43 of the clutches C at or adjacent one mechanism 21 are connected in the energizing lead-s X governing the motor M associated with the other mechanism 21 and the leads Y from the solenoid .coils 43 of the clutches C adjacent the said other mechanism 21 are connected in the energizing leads X of the motor M associated with the first mentioned mechanism 21. When an end of the opaque band 41 passes the photo-electric cell 45 the'switch 41 is operated to de-energize the motor M and the coils 43 which have been energized to effect movement of the record I0 and to energize the other motor M and the other coils 43 and thus effect movement of the record III in the opposite direction. Power lines or conductors 50 supply the reversing switch 41 with current and a manual switch is provided in one of the lines 50 to govern the apparatus.

The electrostatic pick-up I3 is influenced by or is responsive to the sound tracks I I of the record I6 to impose electric current modulations on the amplifier and loud speaker unit I4 which reproduces the sound matter of the tracks. II. The

pick-u I3 includes a body 52 of Bakelite or other insulating material supported on a shelf 53 on the frame member 20. A groove 54 is provided in the upper side of'the body 52 to receive and guide the record II]. The body 52 is preferably positioned midway between the pulleys 24 and in a. plane above the pulleys. The bottom walls of the groove 54 are inclined or .curved downwardly in opposite directions toward the pulleys 24. The record I6 is trained over the body I '52 to bear on the bottom wall of the groove 54 with suitable pressure whereby the record is maintained taut or under proper tension.

The pick-up I3 includes two

field members

55 and 56. The field' member 55 is positioned in the body 52 below the record I0 and the field member 56 is located above the record. The

field members

55 and 56 are formed of suitable electrical conducting material and their opposing edge portions are tapered to relatively narrow edges to produce concentrated fields. The lower field member 55 is proportioned to oppose or face only one track II of the record III and is shiftable between positions opposing the sound tracks II by the means I5. The upper. field member 56 is normally stationaryand is of suflicient length to extend transversely across the major portion of the record III to be responsive to all of its sound tracks I I. The field members 55-and 56 have their opposing edges spaced from the record III to leave a field gap or field space through which the record moves.

The upper field member 56 of the pick-up I3 is carried by a gate 51. The gate 51 is shiftable to a position to permit the easy threading of the record III in the groove 54. The gate 51 is of Bakelite or other insulating material and has one end carried by a pivot pin or hinge pin 58 on the body 52. Cooperating shoulders 59'? of the body 52 and gate 51 hold or stop the gate 51 in the position where its field member 56 is in proper relation to the record III. A spring clip 66 or the like, may be provided to releasably hold the gate 51 in its down position where the field member 56 extends across the upper face of the record ID. A handle 6| may be provided on the gate 51 to facilitate its manipulation.

Conductors 62 extend from the

field members

55 and 56 to a suitable pre-amplifier 63. The conductor 62 connected with the field member 56 has a flexible portion at the gate 51 to allow pivoting of the gate. An automatic switch electrically connects the other conductor 62 with the lower field member 55. This switch may comprise a flexible contact or brush 63 electrically connected with the field member 55 and a contact strip 64 on the bottom wall of a slot -65 in the body 52. The contact strip 64 is electrically connected with the conductor 62. The slot 65 extends transversely of the groove 54 and the contact brush 63 bears against and-moves on the strip 64 during movement of the field member 55 transversely of the record. Conductors 66 connect the pre-amplifier with the amplifier 61 of the unit 94 and leads or conductors 68 connect the amplifier 61 with a suitable speaker 69. Movement of a variable area or variable density metallic sound track II through the field of the pick-up I3 produces fluctuations in the circuit of the pick-up which modulations or fluctuations are imposed on the speaker unit I4 through the medium of the pre-amplifier 63 and the amplifier 61 to be reproduced as sound. The metallic sound tracks II are in effect the movable armatures of the pick-up I3 for successively cooperating with the spaced sound tracks II operates to shift the field member 55 between the positions where .it opposes or faces the individual spaced sound tracks. The means I5 includes a shiftable rod carrying the field member 55. The rod 10 is of insulating material or is suitably insulated from the field member 55. The rod 10 extends through the slot 65 and passes outwardly through an opening H 'in the pick-up body 52. A knob or handle 12 is provided on the outer end of the rod 10 to facilitate its manual operation. The means I5 includes a fixed shaft 13 projecting from the frame-member 20 adjacent the rod 10. The shaft 13 is parallel with the rod 10 and has an annular fiange 14 on its outer end. A rotatable sleeve is provided on the,shaft 13 and has an annular flange 16 cooperating with the fiange 14.

Longitudinally spaced discs 11 are fixed to the I rotatable shaft 15. The number and the spacing side of a--disc 11; The finger 19 is shaped and proportioned to readily pass through the slots 18. The parts are proportioned and related 30 that the engagement of the finger 19 with the innermost disc 11. locates the field member-55 in proper relation to the sound track It at one edge of the record i0.

Means is provided to automatically turn the sleeve 15 a partial rotation at the end of each movement of the-record III to successively align the slots 18 of the discs 11 with the finger 18 and thus allow the successive transverse advancement of the field member 55 from one track |l to the other. A solenoid coil 8| is mountedon the member 20 below or adjacent the shaft 13. A ratchet wheel 82 is fixed on the sleeve 15. A pawl arm 83 is freely movable or pivoted on the shaft 13 adjacent the ratchet wheel 82. A spring pressed pawl 84 is carried by the arm 83 and is adapted to cooperate with the teeth 82 of the wheel. A link 85 is pivotally connected with the arm 83 and the armature 88 of the coil 8|. A spring 81 is connected with the arm 83 to return t e arm and the armature 86 when the coil 8| is de-energized. A stop 88 is provided to limit the returnmovement of the arm 83. The pawl 84 on the arm 83 normally engages a tooth 82.

When the coil 8| is energized the pawl 84 cooperates with a tooth 82 to turn the sleeve 15' and bring a slot 18 to aposition where the finger 18 passes through it to be stopped by the adjacent disc 11. This movement of the finger 19 is accompanied by corresponding movement of v the -fleld member 55 and the'finger 18 is stopped t p p rly align t e field member 55 with a sound track Ii. Leads 88 extend from the terminals of the coil 8| and areconnected in the leads or conductors 48 of the photo-electric cell .45 whereby the coil is under the control of the cell. Accordingly, upon excitation of the cell 45,

when an end of the opaque band 41 passes the cell, the coil 8| is energizedto permit the advancement of the field member 55 to a position in nment with the next or adjacent sound track II. This shifting of the member 55 is substantially simultaneous with the de-energization of one motor M and the energization of the other motor M as above described. The flange 18 of the'sleeve 15 is engageable by the'finger 18 to limit the transverse movement of the field member 55 after passage through the slot 18 in the outermost disc 11. Movement of the finger 18 from the outermost disc 11 to the flange 18 brings the field member 55 to a position where the brush.

contact 83 is out of engagement with the contact strip 54 so that the pick-up unit I8 is automatically lie-energized when the last'sound track has completely passed through the, pick-up.

Aligned slots 88 are provided in the four inner discs-11 in alignment with the slot 18 of the outer or fifth disc to-permit the manual return of the finger 11 from the flange 18 to the inner side of the innermost disc-11. The parts are related so that the finger 19 does notenter the slots so when the apparatus is in operation.

Means is provided for automatically de-enerfrom the outermost disc 11 to the flange 18. This engagement moves the contact 98 out of engagement with the contact 92 to break the circuit to the lamp 45.

To condition the apparatus for operation a record In is flrstarranged in and threaded through the apparatus. -The reel i8 bearing the record Ill may be arranged on a shaft 22 to turn therewith. The record In is trained over the adjacent pulley 24 and then through the pick-up I3. The gate 51 may be lifted to facilitate the easy arrangement ofthe record Ill through the pick-up. The gate 51 is, of course, returned to its down position following the threading of the record. The record II is then trained over the other pulley 24 and secured to the hub H of the adjacent reel i8 to be wound on the reel. The field member 55 of the pick-up I3 is manually adjusted or moved to the end position where it is properly aligned with the first sound track ll of the record. .The manual switch 5| may then be closed to energize the apparatus.

A motor M drives or rotates the reel shaft 22 of the empty or take-up reel l8 and drives the adjacent pulley 24 through the speed reduction mechanism 21. As above described, the coils 43 of the clutches C. controlling the other reel 6 and the other pulley 24 are energized whereby the clutches C are released to permit free unreeling of the record from the loaded reel i8. It is preferred that the sound tracks ii and the band 41 terminate some distance from the ends of the record iii to permit the proper threading of the record in the apparatus and to permit initial movementof the record before a sound track passes through the pick-up l3. The arrow in Fig. 1 of the drawings illustrates the direction of movement ortravel oi. the record l8 when the device is conditioned and energized, as Just described. The record i8 is moved at a constant rate and is taken up on the take-up reel i5 after it is drawn over the actuated pulley 24. Thei of thepick-up circuit and thus produce. electrical v modulations or fluctuations which are imposed on the loud speaker I 4 to be converted into sound. The opaque band 41" passes between the cell 45 and its exciting lamp 48 to maintain the cell in a normal condition. As the record llmay be of great length the sound track l'l may constitute the record-of a. complete sound recording. when substantially the-entire record It has been wound upon the take-up reel l8 the end of the first sound track ll may pass through the pickup It at which time, or immediately subsequently, the endoi. the opaque band 41' passes the cell 45. The lamp 48 then excites the cell 45 to energize the coil 8| and the coil 48. Energization of the coil 8| effects'a partial rotation of the sleeve 15 through the medium of the pawl 64 and the ratchet wheel 82 to bring the slot I8 of the first disc to a position to receive or pass the finger 79. The spring moves the rod outwardly until the finger I3 strikes the second disc 11. This movement of the rod 70 brings the field member 55 into alignment with the second sound track II: The above described energization of.. the coil 48 throws the switch 41 to de-energize th motor M which has effected the movement of the iecord II) and the coils 43 of the clutches C at the other end of the apparatus, and simultaneously energizes the other motor M and the other coils 43. The record I0 is thus moved in the opposite direction to the arrow in Fig. 1, being drawn through the pick-up I3 by the actuated pulley 24 and wound upon the adjacent reel I6: This moves-the second sound band or track I I through the pick-up I3 in the proper direction. the second sound band H actuates or influences the pick-up I3, which in turn energizes or influences the speaker unit I4 to reproduce the sound matter of the second sound track. The record ID is again substantially entirely re-wound on the reel I6 and upon the passage of the end of the second sound track II through the pick-up I3 the cell 45 is again excited to energize the coil 8| and actuate the switch 41. Thus the apparatus is automatically conditioned to move the record ID in the opposite direction to have its third sound track II passthrough the field of the pick-up I3.

The above described operation continues until the end of the last sound band or track I I passes through the pick-up I3. Substantially simultaneously with the passage of the last track II through the pick-up l3 the end of the opaque band 41 passes the cell 45 again efiecting excitation of the cell. results in the release of the "finger 49 from the last or outermost disc 11 and actuation of the reversing switch 41. When the finger 13 passes through the slot I8 of the outermost disc 'II it moves outwardly to strike the flange I6. This movement is accompanied by movement of the brush contact 63 beyond the end of the contact strip 64 thus breaking the circuit to the pick-up I'3. Movement of .the finger 19 against the flange I6. is also accompanied by engagement of the in-.

sulated part of the member 55 with the contactor 93 to break the circuit to the lamp 46. Thus the pick-up I3 and'the photo-electric cell are automatically de-energized when the last sound track II haspassed through the pick-up. The reversal of the switch 41 energizes a motor M to eifect the rewinding of the record II] on its original reel I6. The switch 5| may then be opened to de-energize the apparatus.

Following the playing or use of the record II) it may be removed from the apparatus and another record Ifl may be threaded or trained through the apparatus, as described above. The pick-up I3 may be easily conditioned for use by moving the finger 19 through the aligned slots to bring it into engagement with the innermost disc 11 which also positions the field member 55 in alignment with the first sound track II of the record. The switch 5| may then be closed to again energize or actuate the apparatus.

Having described only typical preferred forms and applications of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear Thus The excitation of the cell 45 to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. Sound reproducing apparatus including, a record comprising an elongate flexible strip, and longitudinally extending sound tracks and a control track on the strip, an electrostatic pick-up, and means for alternately moving the record longitudinally in opposite directions through the field of the pick-up to cause the sound tracks to successively cooperate withthe pick-up} said means being governed by the control track on the record.

2. Sound reproducing apparatus including, a record comprising an elongate flexible strip carrying a control record and a plurality of transversely spaced longitudinally extending sound tracks on the strip, a single pick-up, means alternately moving the record strip longitudinally past the pick-up to cause the sound tracks to successively influence the pick-up, and means conditioning the pick-up for successive response to the sound tracks, the said means being controlled by the control record.

' 3. Sound reproducing apparatus including, an elongate flexible paper record having a control record and a plurality of transversely spaced longitudinally extending non-magnetic, metallic sound tracks on the record, means operable to move the record longitudinally in opposite directions, a pick-up adapted to be influencedby the soundtracks, .and a control for said means whereby the said means alternately moves the record in opposite directions, the con- ,trol being governed by the control record.

4. Sound reproducing apparatus including, an

elongate flexible record, a plurality of transversely spaced longitudinally extending sound tracks on the record, an electrostatic pick-up comprising a relatively stationary field member, means controlled by the record for shifting the field member, and a shiftable field member, means alternately moving the record strip longitudinally in opposite directions past the field members, and means for aligning the movable field member with a sound track upon each change in the direction of movement of the record.

5. Sound reproducing apparatus including, an elongate'flexible record, a plurality of transversely spaced longitudinally extending sound tracks on the record, an electrostatic pick-up comprising a relatively stationary field member, and a shiftable field member, means for moving the record longitudinally in opposite directions,

means controlled by the record for shifting the movable field member into alignment with the sound tracks, and an automatic control for said means for effecting reversal of movement of the record and shifting of the movable field member into alignment with an adjacent sound track when the'end of a-sound track passes the picking the shiftable field member, and an automatic control for the last mentioned means controlled by the record to effect the automatic alignment of the shiftable field member with an adjacent sound track upon the end of a sound track passing the pick-up.

7. Sound reproducing apparatus including, an

elongate flexible record, a plurality of transversely spaced longitudinally extending sound tracks on the record, an electrostatic pick-up comprising a relatively stationary'field member,

and a shiftable field member, means for shifting the shiftable field member between positions where it isaligned with the several sound tracks, and a control for the last mentioned means operable to automatically efl'ect shifting of the elongate flexible record, a. plurality of transversely spaced longitudinally extending sound tracks on the record, an electrostatic pick-up comprising a normally stationary field member,

a shiftable field member, and means supporting 5 one field member for movement away from the other field member to facilitate the threading of the record between the members, means operable to alternately move the record longitudinal:-

ly in opposite directions, and means controlled 1 by the record for shifting the shiftable field member at the end of each movement of the record to align it with an adjacent sound track.

VICTOR H. SEVERY.