US2273391A - Apparatus for reproducing and recording sound - Google Patents

Description

Feb. 17, 1942. s. YERKOVICH 2,273,391

APPARATUS FOR REPRODUCI NG AND RECORDING SOUND I Filed June 19, 1939 2 Sheets-Sheet 1 m 7 L J INVEN TOR 5/)110/2 YerAar/ck ATTO R NEY Feb. 17, 1942. I s. YERKQVICH 2,273,391

APPARATUS FOR REPRODUCING AND RECORDING SOUND Filed June 19, 1939 2 Sheets-Sheei 2 INVENTOR 7? 0/2 )rfo V/c/I BY W ATTORNEY Patented Feb. 17,1942 i p Y UNITE-D1- STATE APPARATUS FOR nErnonUcmG AND neconnnvc SOUND 7 Simon Yerko'vlch, Lcs Angeles, flalif assignor to United Acoustlgraph-Corporation, Los Angeles,

CaliL, a corporation of Nevada Application June 19, 1935}, Serial No. 279,849

11 Claims.

This invention relates to sound recording and reproducing apparatus, and more particularly to apparatus that incorporates a stylus in contact with a record or a record blank.

In such apparatus, the blank for receiving the sound record may be in the form of a thin' endless flexible loop or band, upon which the vibrating stylus impresses or cuts the undulations that correspond to the sound. In reproducing,

the stylus point is permitted to follow the record grooves freely, and 'such movement causes corresponding current variations in a translating CllOllliL' In both recording and reproducing, the

ture, the apparatus embodying the invention is effective to control the operation fof the stylus-for bothrecording and reproduction purposes.

- This invention possesses many otherfadvan-f tages, and has other objects which may be made more easilyapparent from a consideration of one stylus must be advanced in a direction transverse to the motionof the record or the blank. This may. conveniently be accomplished by a lead screw, engaging a carriage upon which the stylus andits associated mechanismis mounted.

It is one of. the objects of this invention to i make it possible to use the same stylus and carriage for recording as well as for reproduction. For this purpose, the stylus is provided with a blunt point suchwas a .sapphire point, which impresses the record undulations in a blank without cutting it, and which can readily follow the record grooves for reproduction, without undue wear.

, It is necessary, for the purposes of recording, that the stylus pointform the record grooves as the carriage advances, and that the stylus be so mounted as to make'it possible to exert an adequate pressure on the blank by the stylus point. Yet when it is desired to reproduce the record, the stylus must be left quite unrestrained so as to enable it effectively to follow the previ-- ously' formed undulationa' other object of this invention to provide a mechanism such that these differing requirements for recording and reproducing may be obtainedat will, as by a convenient adjustment or control.

n One of the important features of the recording .and reproducing stylus structure is that the stylus can be vibratedto cause considerable pressure for recording, and-the stylus yet is maintained against. appreciable movement under. the

forces acting on the stylus that are} useful for producing the record; and ,yet, when the stylus. is used for reproduction purposes, it is sufliciently yielding to permit the stylus. to' follow the. record grooves and undulations; rhea-structure by the aid of ISflrCCDIQPMQdiS'dGSCPibGd Bind It is therefore an- 5 a claimed-in a qp nd li evaluation. entitledv cording and jreproducing head, Serial Nof record.

Name, mf qnjunctionwith suchastylus 'struo: 5 5

embodimentof the invention. Forthis purpose there is shown. a formin the drawings'accompanying and forming part of the'pre'sent'specification, This form willno'wbe described indetail, illustrating the general principles oftithe invention; but itis to be understood that detailed description is not to be taken in a-limiting sense, since the scope of this invention is best defined by the appendedclaims, a

Referring to the drawings:

Figure 1 is a view, partly in'longitudinal section, of an apparatus incorporating the invention and shown as in use for'reproducing;

Fig. 2 is a side view of the apparatus illustrated in Fig. 1. Y

Figs. 3, 4 and 5 are sectional -views taken respectively along the planes 3-3, H and 5- 5 of Fig. 1; r

Fig. 6 is a fragmentary view similar to Fig, 1, illustrating the apparatus in use for recording;

Fig. 7 is a top plan view of the mounting structure of the stylus utilized in connection with the In the present instance, the record member l is shown as a thin, flexible loop adapted to be .disposed over the. rollers 2 and} appropriately -mounted and arranged to move the record member past a vibratory stylus-l. In the recording, as well as in the reproducing position, the tip of the stylus, which may be formedof some, gem point, such as sapphire, may bepla'ced against .the record member I opposite an anvil member 5 (Figs. 1 and 6) disposed .back of the recor'd'member I and capable of being turnedto the "active 3 position illustrated in these i -The stylus 4 is incorporated generally'in' a stylus structure .or head structure 6 in detail in the aforementioned application filed in the name ofB emard F. McNamee. general it may be stated for the present stylus structure provides for the. vibration ofthe, stylus 4 about an axis I, causing the stylusl to make a lateral record, or to bervibrated aboutfthe axis 1 by playing in a groove carryingsucha lateral In reproducing the sound, the stylu verse to the surface I.

6 is intended to be nioved at a substantially uniform rate in a direction transverse of the exposed surface of the record member This is ordinarily accomplished by the aid of a carriage structure U advanced for example as by a threaded lead screw 8 (Figs. 1 and 2). This lead screw may be appropriately supported for rotation as in the side members 9 and ID of a stationary frame. It may be rotated by any appropriate source of motion such as a small electric motor (not shown). .The carriage structure U (Figs. 1, 2 and 3) is arranged to be moved by the lead screw 8 as by the aid of a half nut |2 fastened to carriage The sides of the carriage H are provided with appropriate apertures for the passage of a stationary guide rod |3 appropriately supported by the frame members 9 and ID. A lower guide rod l4 of similar structure to guide rod 3 is engaged within the slots |5 in the lower portion of the carriage The rods 13 and I4 thus restrain the carriage I from any movement other than in a direction parallel with the axes of the guide rods I3 and I4.

It is essential when the stylus 4 is used for reproduction that it be quite free to follow the record groove and its lateral undulations. For this purpose it is desirable so to mount the stylus 4 as to permit it to'move in a direction transverseto the record surface. At the same time 'the stylus 4 should be so mounted that it is caused to vibrate about its own axis 1 through the minute amplitudes corresponding to the undulations in the sides of the record groove. A force must also be provided for urging the stylus point into the groove. By the aid of the present mounting illustrated in Figs. 1, 2, 3 and 4, these requirements are adequately provided for.

. Thus the'stylus structure 6 is shown as mounted on top of a supporting member 80 having a rearwardly extending portion i8, as well as downwardly directed arms I! and Hi. These arms Ii and l 8 are shown as provided with headless conical pointed pivot screws l9 and 2G, by the aid of which the supporting member 80 is pivotally mounted on an axis parallel to the surface of the record member I. For this purposefthe pivot screws l9 and 28 engage a block 2| extending upwardly between the arms ii and I8. This block 2| is provided with downwardly directed arms 22 and 23. pivot for the structure 6 about an axis trans- For this purpose there are shown a pair of headless conical pivot screws 24 and 25 threaded respectively through the arms 26 and 21 of a bracket 28. This bracket 28 is appropriately supported on top of the carriage Without further provisions, it is seen that the structure 6 has freedom of motion about a pivot 29-parallel to the record surface i, as well as about a pivot 33 transverse to the record surface I. Accordingly, as the carriage H is advanced by the lead screw 8, the structure 3 can accom-' modate itself to the vagaries of the groove in the record member of the parts is such that the minute undulations in the walls of the groove cause the stylus to be vibrated about its own axis 7, and thereby affect anappropriate pickup circuit. One of the terminals for this circuit is indicated at 3| in Fig. l.

A light resilient force is provided for keeping the stylus 4 in contact with the groove same time a light, resilient force is also provided tending to keep the structure 6 centralized about These arms provide a At the same time the inertia an angle bracket 32 fastened to the left hand At the the transverse axis 30. The manner in which this is accomplished will now be described.

Thus the arm or extension |6 formed on the support is subjected to the upward pressure of a compression spring 8| (Figs. 1 and 2). The lower end of this compression spring rests upon edge of carriage I I. The upper end of the compression spring 8| carries a disk 33 disposed immediately below the bottom of an adjusting screw 34 passing through the extension H5. The spring 8| thus urges the extension I6 upwardly, and

\ thereby the structure 6 about the axis 29 parallel to the surface of the record.

To provide the centralizing resilient force about the axis 30, use is made of a bar spring 35. This bar spring 35, as shown most clearly in Fig. 2, extends axially of the screw 34 and may be fixed therein. It extends downwardlythrough the disk 33 and through the spring 8|, which surrounds the bar spring 35. The bracket 32 is provided with a large clearance aperture 36 to permit passage of the bar spring therethrough, irrespective of the angular position of the support 80 about its axis 29. The free or lower end of the bar spring is accommodated in a slot 3! formed in a bracket 38 attached adjacent the lower edge of the carriage The slot 3'! extends in a direction parallel to the transverse axis 3|]. By engagement of the lower end of the bar spring 35 with one or the other wall of the slot 31, this bar spring 35 is flexed by the force exerted upon it whenever the structure 6 is urged away from a central position with respect to the axis 30. The force of the bar spring tends to keep the structure 6 in a vertical position, but readily permits the structure nevertheless to depart slightly from'this vertical position as required by the restraint imposed upon the stylus 4 by the walls of the record groove.

These light resilient forces provided by the springs 8| and 35, while essential for purposes of reproduction, should be altered during the process of recording with the same stylus 4. For

a recording purposes, for example, a much greater force should be exerted, urging the stylus 4 toward the recording surface; and the structure-|5 must be restrained from any motion whatever about the axis 33. In this way, sufficient forces may be caused to be exerted upon the stylus 4 for obtaining a requisite pressure not only to form the record groove, but also its lateral undulations.

A simple mechanism is provided for ensuring that during the process of recording these restraints and forces be properly proportioned.

Thus for example the restraint against motion about the axis 30 is accomplished in the present instance by providing a cam member 39 (Figs. 1, 3, 4 and 6). This cam member is shown as extending beneath the block 2| and as supported on a rotary shaft 40, journaled in arms 4| and 42 provided on the support 43. This support 63, as shown most clearly in Figs. 3 and 4, is supported upon the top surface of the carriage i. The shaft 48 is restrained against axial movement as by the collars M and 35.

The cam 33 is of general circular configuration: but at its top surface it has a flattened portion lofi' In the position of Figs. 1 and 3, this flattened top portion $3 is substantially parallel with the lower surface 6? of the block 29. It therefore is out of the path of movement of the block 2|, as block 25 pivots about the axis 3!].-

been rotated so that the circular surface of the cam now engages the bottom surface or pad 41 of the block 2|. Accordingly due to the engagement of thecylindrical surface of the cam 39 withthe surface 41, rotation about axis 30 is prevented.

Provision are made also, for the period'of recording, to supplement the resilient force of the spring 8|. For this purpose the lower. end of the extension [6 carries a flat spring 48 (Figs. 1, 4 and 6). The free end of the flat spring in the 'reproducing position of Fig. 1 is left inoperative.

However, the free end of the spring may be engaged by a corner of'a block 49 (Figs. 1. and '6) so as to impose a pressure upon thi free end and supplement the pressure of the spring 8|. ,In the reproducing position, as shown most clearly in Fig. 5, the flat upper surface'ill of the block 49 clears f the lower end of the spring 48. One corner, however, maybe moved into contact with the fiat. spring uponrotation of the block 49 about an axis 5| of a shaft 52. This shaft52, as shown most clearly in Fig. 2, is rotatably supported in the frame members 9 and w. The block 49 is splined't the shaft 52. It is arranged to be carried along with the carriage H, as by the uldof the projection 53, which engages the arcuate slot 56 in the bottom of the block 39 (Fig. 5). This projection 53 is shown as integral with the top of the carriage H.

The shaft 52 is provided at its left hand end with a, manipulating lever or handle 55 (Fig. 2). By the aid of this handle 55 the angular motion of the block 19 may be controlled. Preferably, however, the manipulation of handle 55 is also rendered eifectiveto rotate the cam shaft 618 for restraining rotation about axis Z-ll. For this purpose the block .19, as shown most clearly in Figs. 1, 4 and 6, is provided with an upwardly extending arm 56. The free end'of this arm is pivotaily joined to a link 57]. The other end of link 5? is pivoted to an arm 523 (Fig. 2) fastened to the shaft dd. Accordingly when the spline shaft 52 is rotated by handle 55, not only is the block it rotated, but a rocking motion is also imparted to the cam shaft till.

The adaptability of the stylus d for both recording and for reproduction is provided for by the aid of the structure disclosed in the aforementioned prior application filed in the name of Bernard F. McNameein Figs. 7 and 8 the essential elements of the stylus mounting are indi cated. Thus the stylus d is shown as accommodated in a saddle extension 5c of an armature, which'is made integral with a tubular support 5i.

This tubular support M is threaded at its upper end for engagement of a thumb-screw 58 by the aid of which the stylus t may be clampedv within this saddle to. The tubular member 66 is journaled in resilient sleeves 62 at the top and bottom of the supporting arms 83 and 615. These supporting arms-- provide .sloping surfaces for the accommodation of the sleeves 62. These sleeves are clamped against thesloping. surfaces 'by a cap 65 attached to the members 83 and 64. The armature which is made of magnetic material, is

' provided with a polar extension 66. This polar extension is accommodated in an air gap 61 between the opposed polepieces B8 and 690i 9. permanent magnet Ill (Figs. 1 and 6). The'coil ll surrounds the armature. Current impulses may be induced in this coil during the reproducing period, as is well understood. For recording pur poses current impulses are passed to coil M for vibrating the armature and the stylus 4. Allthis has been detailed in the prior application hereinbefore referred to.

In order to restrain lateral movement of the support 6| parallel to the record surface during the recording operation, while. yet permitting the stylus 4 to be, vibrated during reproducing operation, use is made of a pair of bar springs 12 and 13. These bar springs extend in a direction lateral to the axis I and generally parallel to the record surface I. One end of each of the springs 12 and 13 is joined permanently to the tubular support 6!. The other end is adjustablyclamped to the bossesli and 16 respectively, as by the aid of the clamping members l1 and 18. By appropriate adjustment of the springs 12 and 13 in the clamping members 11 and 18, the stylus and its tubularsupport 6| can be accurately centered with respect to'the air gap 61. A strong restraint isreproducing impulses in connection with a surface of a record member, said structure including a stylus adapted to vibrate about an axis, a carriage movable parallel with said surface, means mounting the structure on said carriage so that the structure may have freedom of motion toward and from the surface, as well as freedom of motion in a direction transverse to the surface with respect to the carriage, means resiliently urging said structure toward said surface, and means for restraining said structure against said transverse motion, as well as for increasing the resilient force acting to urge said structure toward said surface, said means including a pair of simultaneously operable rotatable members on the car riage.

2. In a devicepf the character described, a stylus structure adapted for recording and for reproducing impulses in connection with a surface of a record member, a pivotal supporting means for the structure on an axis parallel to said surface, another pivotal support for the said supporting means on an axis transverse to the axis of the supporting means, a resilient means acting on the said supporting means for urging said structure toward said surface, and means for imposing an additional resilient forc on said supmeans for restraining movement of the structure about said transverse axis, comprising a rotatable carn'rneljnber on the carriage.

3. Ina device of the character described, a stylus structure adapted for recording and for reproducing impulses in connection with a surface of a record member,- and a mounting for the structure, comprising a carriage movable parallel with said surface, a supporting means for said structure, means mounting said supporting means on said carriage including a pivot mounting said supporting means on an axis parallel to said surface, as well as a pivot mounting said supporting means on an axis transverse to said surface, a spring urging the'supporting means toward the surface, and means actin to centralize the structure about the said transverse axis with respect to the carriage, comprising a bar spring interposed between the carriage and the mounting means.

4. In a device of the character described, a stylus structure adapted forrecording and for reproducing impulses in connection with a. surface of a record member, and a mounting for the structure, comprising a carriage movable parallel with said surface, a supporting means for said .structure, means mounting said supporting 5. In adevice of the character described, a

stylus structure adapted for recording and for reproducing impulses in connection with a surface of a record member, and a mounting for the structure, comprising a carriage movable parallel with said surface, a supporting means for said tructure, means mounting said supporting means on said carriage including a pivot mounting said supporting means on an axis parallel to said surface, as well as a pivot mounting said supporting means on an axis transverse to said surface, a spring urging the supporting means toward the surface, spring means arranged between the supporting means and the carriage to centralize the structure about the said transverse .axis, and means for restraining movement of the structure mounting against movement about said transvers axis, comprising a, rotatable cam member interposed between the carriage and a surface of the mounting means.

6. Ina device of the character described, a stylus structure adapted for recording and for reproducing impulses in connection with a surface of a record member, and a mounting for the structure, comprising a, supporting means for said structure, a pivot mounting for said supporting means, on an axis parallel to said surface, means resiliently urging said supporting means about said axis toward said surface, a flat spring attached at one end to the supporting means, and means including a rotatable block for optionally engaging the free end of the flat spring, to increase the resilient force acting on the supporting means.

7. In a device of the character described, a stylus structure adapted for recording and for reproducing impulses in connection with a surface of a record member, a mounting means for said structure on axes respectively parallel and transverse to the surface, a. spring operating on the mounting means. and urging the structure about the parallel axis and toward said surface, a

fiat spring having one end attached to the mounting means, means optionally engaging the free end of the flat spring for increasing the force urging the structure toward the surface, and means operating optionally to restrain the structure about the transverse axis, comprising a rotatable cam member interposed between the carriag and a surface of the mounting means.

8. In a deviceof the character described, a stylus structure adapted for recording and for reproducing impulses in connection with a surface of a record member, a mounting means for said structure on axes respectively parallel and transverse to the surface, a. spring operating on the mounting means and urging the structure about the parallel axis and toward said surface, a fiat spring having one end attached to the mounting means, means optionally engaging the free end of the flat spring for increasing the force urging the structure toward the surface, means operating optionally to restrain the structure about the transverse axis, and a connection between the liat spring engaging means and said restraining means for simultaneously operating both of said means.

9. In a device of the character described, a stylus structure adapted for recording and for reproducing impulses in connection with a surface of a, record member, a carriage movable parallel with said surface, means for mounting said structure on said carriage for movement about an axis transverse to said surface, and means for centralizing said structure about said axis, comprising an elongated bar spring fixed at one end to said structure, and means forming a slot on the carriage extending in a direction parallel to the axis and into which the other end of said bar spring enters.

10. In a device of the character described, a stylus structure adapted for recording and for reproducing impulses in connection with a surface of a record member, acarriage movable parallel with said surface, means supporting said structure on said carriage including means pivotally mounting the structure on an axis parallel to said surface, as well as about an axis transverse to said surface, a bar spring carried by the means mounting the structure about the-parallel axis, means carried by the carriage forming a slot extending parallel to the transverse axis for accommodating the free end of the bar spring, and a compression spring surrounding the opposite end of the bar spring for urging the structure toward the surface about the parallel axis.

11. In a device of the character described, a stylus structure adapted for recording and for reproducing impulses in connection with a surface of a record member, a carriage movable parallel with said surface, means supporting said structure on said carriage including means pivotally mounting the structure on an axis parallel to said surface, as well as about an axis transverse to said surface, a bar spring carried by the means mounting the structure about the parallel axis, means carried by the carriage forming a slot extending parallel to the transverse axis for accommodating the free end of the bar spring, a compression spring surrounding the opposite end of the bar spring for urging the structure toward the surface about the parallel axis, and means for restraining movement of the structure about the transverse axis with respect to the carriage as well as for increasing the resilient force urging said structure toward said surface, said means including a pair of simultaneously operable rotatable members on the carriage.

SIMON YERKOVICH.

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