US1992893A - Combined recording and reproducing device - Google Patents

Description

Feb. 26, 1935. A, A. THOMAS 1,992,893

COMBINED RECORDING AND REPRODUCING DEVICE Filed March 24, 1931 2 Sheets-Sheet l INVENTOR Feb. 26, 1935. A A, THQMAS 1,992,893

COMBINED RECORDING AND REPRODUCING DEVICE Filed March 24,'1931 2 sheets-sheet 2 INVENTOR @WMM Patented Feb. V26, 1935 UNITED STATES PATENT OFFICE Adolph A. Thomas, New York, N. Y., assignor to Radio Corporation o! America, a corporation of Delaware Application March 24, 1931, Serial No. 524,856

20 Claims.

My invention relates to the art of recording and reproducing sound, and its object is to provide a unitary electric device which carries two separate stylus members, one adapted to operate as a recording tool and the other as a phonograph needle. This device is readily adjustable on its support to bring either stylus member into playing position.

In home recording machines that have hitherto appeared in the market, the electric pickup is also used for recording, but it is necessary to remove the reproducing needle and insert a recording stylus. Then, after a record has been made, the cutting stylus must be taken out and a playing needle inserted. VThisv changing of stylus members is bothersome, and there is the further objection that the loose recording stylus is easily lost or misplaced. Also, in those prior machines, there is a loose weight which is supposed to be placed on the pickup casing when making a record, because the cutting stylus must be held in the preformed groove of the blank disk with a certain amount of pressure. A loose weight like that is easily forgot, especially when not insight, and in a house where there are children itis liable to become lost or mislaid. Then, too, a person (especially a child) may drop the loose weight on a record and break the latter.

The foregoing and other objections and disadvantages in prior home recording machines are overcome by the combined recording and reproducing unit of my invention, in which the presence of two separate stylus members makes it unnecessary to substitute one for the other. This double-acting device is always in condition for recording or reproducing, it being only necessary to adjust it to proper position on its supporting arm. This is so simple that even a child can do it. The supporting arm of the recording and reproducing unit preferably carries a weight which can be swung forward to rest on the unit or rearward into inoperative position.

The novel features and practical advantages of my invention will be fully understood from a description of the accompanying drawings, in which:-

Fig. 1 is a side view of my recording and reproducing device shown in recording position, certain parts being sectioned for clearness;

Fig. '2 represents an enlarged plan view in section on line 2-2 of Fig. 1;

Fig. 3 shows a vertical section on line 3,-3 of Fig. 2;

Figs'. 4, 5 and 5a are transverse sections on lines 1 -4, 5-5 and 5dr-5a respectively, of Fig. 3;

Fig. 6 is a side view of a modified form of Amy invention, the device being in reproducing position;

Fig. 'I shows the inside mechanism, partly sectioned, of the modified construction;

Figs. 8 and 9 represent sectional views on lines 8-8 and 9-9, respectively, of Fig. '7; and

Fig. 10 shows the device of Figs. 6-9 in recording position.

Referring to the construction illustrated in Figs. 1-5, the combined recording and reproducing unit comprises a casing 10 adjustably mounted on a supporting arm 12. The casing 10 in the present instance is a iiat rectangular box closed at one side by a removable plate 13, which is attached to the' body of the casing in any practical way. The parts 10 and 13 are made of nonmagnetic material, such as brass, aluminum, duralumin, and the like; or they can be molded of composition material consisting of phenolic condensation products. For lightness and durability I prefer to make the casing parts 10 and 13 of aluminum or its alloys, and the box section can be shaped from sheet material in a single operation. The cover plate 13 terminates at the rear in a vertical wall 14, which is provided with a hub 15 adapted to rit into the front end of the supporting arm 12. The parts 14 and 15 may be cast or molded as integral extensions of cover plate 13.

The hub 15 acts as a rotary bearing for the casing 10 and permits adjustment of the recording and reproducing unit to either of two operative positions, as presently will be explained. The rotary adjustment of casing 10 on the supporting arm 12 is limited to approximately 180 degrees or half a, revolution. Any practical means may be employed to limit the movement of casing 10 and hold it rmly in either position. By way of example, I have shown the supporting arm 12 provided With a radial slot 16 through which projects a set-screw 17 carried by the hub 15 of casing 10. As shown in Fig. 5, the slot 16 encompasses an arc of a little more than 180 degrees, so that the axis of set-screw 17 moves through half a circle when the casing 10 is adjusted from one position to the other. The underside of arm 12 carries a small housing or thimble 18 in which a yieldable pin 19 is movably mounted. An expanding coil spring 20 in housing 18 tends to push the pin 19 upward into a pair of rounded notches or recesses 21 of hub 15. These notches are arranged 180 degrees apart, so as to receive the rounded end of pin 19 when the casing 10 is in either one of its two operative positions. In other words, the springrotary sleeve is journalled. A setscrew 26 on post 24 projects into an annular groove 27 in sleeve 25 to hold the latter against axial movement without interfering with its rotational adjustment during the making or playing of arecord.

The roary sleeve 25 has a top plate 28 adapted to rest on the upper edge of post 24, and a pair of spaced ears or lugs 29 on the top plate support a cross-pin or stud 30 between which the arm 12 is provided. It will be seen that the supporting arm 12 is capable of horizontal swinging movement about the rotary sleeve 25, and also has the necessary vertical movement about the horizontal cross-pin 30. Any other practical mounting for arm 12 may be used in place of the one above described.

A U-shaped permanent magnet 31 is mounted rigidly on the base plate 13 of casing 10 in any practical way, as by screws 32. Two U-shaped pole pieces 33 and 34 are secured to the ends of magnet 31 by magnetic screws 35, or otherwise. The pole pieces 33 and 34 are preferably made of soft iron or other metal having a high magnetic permeability. The ends of pole pieces 33 and 34 are usually tapered and provide a pair of aligned airgaps 36 and 37. At least one of the pole pieces 33-34 carries a coil 38, but I' prefer to add a second coil 39 on the other pole piece. These coils are preferably connected in series and arranged at opposite sides of the airgaps 36-37, as will be clear from Fig. 2. If necessary, the front end of casing 10 and the base plate 13 are shaped to provide recesses 40 and 41 for accommodating the coil or coils 38-39. The width of the permanent eld magnet 31 may be practically the same as that of base plate 13, so that the sides of casing 10 fit snugly against the sides of the magnet. This arrangement permits the use of a magnet of maximum Width, and at the same time serves to strengthen the sides of casing 10, so that the latter can be made of thin sheet material.

A T-shaped non-magnetic bracket indicated as a whole by 42 is secured to base plate 12 by one or more bolts 43, and the ends of the bracket may be attached to magnet 31 by screws 44. The bracket 42, which may be used to hold the magnet 31 in place Without the screws 32 and 44, has an integral arm 45 extending forwardly and provided ,at its free end with an open slot 46. As shown in Fig. 2, the slot 46 is arranged at an angle and terminates in a shouldered recess 47 adapted to receive one end of a spring blade or shaft 48. The other end of spring blade 48 is mounted in a shouldered recess 49 arranged at the inner end of an open slot 50 in base plate 13. As shown in Figs. 2 and 4, the shouldered recesses 47 and 49 slant in opposite directions at a slight angle, so as to maintain the spring blade 48 in twisted and tensioned condition. The open slots 46 and 50 in bracket arm 45 and base plate 13 permit easy insertion of spring blade 48, which is automatically twisted and tensioned when the ends of the spring snap into the slanting recesses 47 and 49. These recesses also lockte spring blade in position without the need of extra fastening means. To prevent axial displacement of spring shaft 48, the shouldered recesses 47 and 49 are covered by small plates 51 and 52 secured to arm 45 and base plate 13 respectively.

A magnetic armature bar 53 is secured to the central portion of resilientshaft 48 in any practical way, :1nd the ends of the armature bar extend into the aligned airgaps 36 and 37, as best shown in Fig. 2. The initial set or tension of spring 48 normally holds the ends of the armature bar 53 substantially midway in airgaps 36-37, so that the armature bar is capable of vibrating about the spring without striking the pole pieces. 'I'he normal balanced position of armature 53 is also due to the balancing effect of the normal flux of field magnet 31. It will thus be clear that the twistable spring 48 not only supports the armature 53, but also acts as resilient restoring means for the armature. It is evident from Fig. 2 that the oscillatory vibrations of armature 53 produce flux variations in coil or coils 38-39. Conversely, when current impulses pass through the coils, the normal eld flux is so unbalanced as to cause vibration of armature 53.

The tensioned spring blade 48 also carries an extension 54 to which a vertical arm 55 is attached at the center. If desired, the parts 54 and 55 may be formed as a single member, preferably of light material like aluminum. The ends of arm 55 carry holders 56 and 57 adapted to receive a recording stylus 58l and a reproducing stylus 59, respectively. A thumb-screw 60 or other sutiable means holds each stylus removably clamped in its holder. The recording stylus 58 is a sharp piece of hard metal, composition or mineral adapted to cut a soundV groove in a disk record 61, While the latter is rotated on a turntable 61'.. In practice it is usual to provide a record blank having a preformed spiral groove in which the point of stylus 58 is placed. The preformed groove acts as a guide for the stylus, and the lateral vibrations of the latter by current impulses in coils 38--39 cut undulations in the side Walls of the groove in accordance with the transmitted sound waves. The material of the record is suiiciently soft to permit cutting of the sound groove by the recording stylus. v

The reproducing stylus 59 is an ordinary phonograph needle adapted to reproduce from a record made by recording stylus 58 or from any other record. The movements of needle 59 in the record groove cause oscillatory vibration of armature 53, and the resulting current impulses in coils 38-39 are amplified to give loud-speaker reproduction. There is no need to show any circuit connections for coils 38--39, because those are Well understood, and furthermore they form no part of my invention. When changing from recording to reproducing, or vice versa, it is only necessary to turn the casing 10 on arm 12 from one position to the other, as previously explained. While the reproducing needle 59 is supposed to be renewed frequently to prevent undue wear on the record, the recording stylus 58 will last a long time and will seldom require attention. In fact, it is possible to make a recording stylus that will last for years, if the record blanks are wax or similar material that is easily cut. The circuit wires for coil or coils. 38--39 may beunited in a cable 62, which passes from casing 10 through the hollow tubular arm l2 and sleeve 25 into the space below the motorboard 23. y

It has been found in practice that, when making a sound record on a blank disk, the recording stylus 58 `requires a certain amount of extra pressure to hold the cutting point firmly in place on the disk. On the other hand, when reproducing from a record, the pressure on the needle 59 should be comparatively light-not more than a few ounces, and it may even be less than an ounce. In prior machines for making phonograph records at home, it has been necessary to supply a loose weight which the operator is supposed to put on the pickup casing during rthe recording operation. This weight must be taken off when playing from a record. As explained in the introductory part of this specification, a loose weight is objectionable and I dispense with it by providing a weight 63 which is adjustably connected to the pivoted arm 12. In the present embodiment of my invention, the weight 63 is fixed on `one end of a rod or link 64 which is pivoted at 65 on a collar 66. This collar is either clamped around arm l2 in a permanent position, or it may be slidably adjustable along the arm. In the latter event, a set-screw 67 is used to clamp the collar 66 in adjusted position. The dotted outlines 66a and 66h in Fig. 1 indicate different positions of collar 66.

During the recording operation, the weight 63 is swung forward on top of casing 10 where it exerts the necessary amount of increased pressure on the recording stylus 58. During the reproducing operation, the weight 63 is swung to the rear of arm l2 into the position indicated by the dotted outline 63a. It will be noticed in Fig. 1 that the weight in its rear position 63a acts as a counterbalance for the weight of the ymechanism inside of casing 10, so that the pressure on the reproducing needle 59 is reduced to a few ounces. This reduced pressure on the needle point not only prevents undue wear on the record, but also lessens the so-called needle noises. It is clear from what has been said that the adjustable weight 63 performs the double function of increasing the pressure on the recording stylus 68 and lessening the weight of the unit on the reproducing needle 59. There is no possibility of the weight 63 being left by chance on casing 10 during the reproducing operation, because the weight must be swung to the rear before the casing can be turned from recording to reproducing position. By adjusting the collar 66 axially on arm 12, the effective pressure and counterbalancing action of weight 63 in its two positions can be regulated for the best results in any particular machine. If no counterbalancing effect of weight 63 is required when it is thrown back, it is only necessary to make the rod 64 of such length that the weight will not project beyond the pivot pin 30 in its rear position.

In the modification shown in Figs. 6-10, the recording and reproducing unit is housed in a casing 68, which is provided with a separable y cover plate 69 held in place by screws or bolts 70.

What has been previously said about the casing parts l0 and 13 in Figs. 1-4 is applicable to the casing parts 68 and 69. Since the construction and mounting of arm 12 in Figs. 6-10'are the same as those previously described for the supporting arm in Figs. l, 2 and 3, it will not be necessary to repeat that description. Also, everything previously explained in connection with the adjustable weight 63 is applicable tothe weight shown in Figs. 6 and 10. For reasons that will presently appear, the casing 68 need only be rotated through an arc of ninety degrees on arm 12 to change from recording to reproducing position and vice versa. For this purpose the casing 68 is provided with a hub 71 which nts over the free end of arm 12, and this hub is provided with a radial slot 72 arranged to receive a set-screw or pin 73 attached to the arm. The slot 72 permits rotation of casing 68 through an arc of ninety degrees, and suitable means (like the springpressed pin 19 of Fig. 3) may be provided to hold the casing lrmly in each position.

A U-shaped permanent magnet 74 is mounted on base plate 69 and is secured thereto by a nonmagnetic cross-bar 75. One or more screws 74' may be used to attach the magnet directly to the base plate. A screw or bolt 75a connects the cross-bar 75 to base plate 69, and shoulders 75h on the cross-bar engage the inner sides of the magnet to lock the latter against movement. If desired, the ends of cross-bar 75 may be connected to the magnet by screws 75e. Two pole pieces 76 of high magnetic permeability are secured to the ends of magnet 74 in any practical way, as by screws or rivets 77. The pole pieces 76 are in the form of straight bars which carry one or two coils 78, preferably connected in series. The coils can be machine-wound and slipped over the ends of pole pieces 76 where they are held in position by cross-pins 79 or otherwise. The base plate 69. is provided with a pair of lugs 80, which may be integral with the plate if the latter is cast or molded. The lugs 80 carry adjustable bearing screws 81 adapted to support a block or trunnion 82 for oscillatory movement. The trunnion 82 constitutes a common pivotal support for three arms 83, 84 and 85. The upwardly extending arm 83 carries a pair of magnetic armature bars 86 and 87 arranged on opposite sides of the polar extensions 76 and on opposite sides of coils 78. The armature bar 87 is notabsolutely necessary and may be omitted, but II believe its presence increases the efficiency of the device, particularly when reproducing. The arm 84 projects through a slot 88 in casing 68 and carries a holder 89 adapted to receive the recording stylus 58. The arm 85 projects through a slot 90 in casing 68 andcarrles a holder 91 for receiving the reproducing needle 59. What has been previously said about the stylus members 58 and 59 in connection with Figs. l, 2 and 3, applies to the same stylus members in Figs. 6-10.

When the casing 68 is turned horizontal, as shown in Figs. 9 and 10, the recording stylus 58 is in operative position on a record blank 61 mounted on turntable 61. The sound to be recorded is converted intocurrent impulses suitably amplied and sent through coil or coils 78, and these current impulses vary the magnetic flux across the two pairs of airgaps 86 and 87' (see Fig. 9), thereby causing vibration of arm 83. The vibrations of arm 83 cause the vertical arm 84 and recording stylus 58 to vibrate laterally in relation to the surface of the record disk. When the reproducing stylus 59 is in operative position, the lateral vibrations.

thereof produced by the undulationsl in the sound groove cause the armature unit 86-87 to vary the argaps 86-87 and thereby induce electric impulses in the coils 78. These impulses are suitably amplified to operate a loudspeaker device, as will be understood without further explanation. As previously suggested, the armature bar 87 may be dispensed with, but it has certain advantages during the reproducing operation, because it shunts the magnetic lines of force away from coil 78 when the arm 83 rocks toward the left. as viewed in Fig. 8. On the other hand, when the arm 83 rocks toward the right, the approach of the upper armature 86 to the pole pieces 76 causes a sudden increase in the field flux through coils 78.

I provide novel centering or restoring means for the armature unit 86-87 in the form of elastic blocks 92 arranged on oppositesides of the pivoted arm 83, as best shown in Fig. 81. The elastic blocks 92, which may be cylindrical pieces of india rubber, are held in sockets 93, and these sockets are adjustably supported on casing 68 andbase plate 69. For this purpose, the sockets 93 have screw extensions 94 which are rotatably adjustable in their respective supports by means of an ordinary screwdriver, and lock nuts 95 hold the sockets securely in adjusted position. The elastic blocks 92 are under initial compression, so that they exert opposite pressures against the arm 83 and thereby hold the amature unit 86-87 at substantially equal distances from the intermediate pole pieces 76. The elasticity of the compressed centering blocks 92 does not interfere with the vibratory movements of arm 83, but they damp the vibrations of the arm and prevent parasitic movements thereof. The arms 84 and 85 project through the casing 68 at the proper trailing angle. When viewed from the front of the casing, the arms 84 and 85 are in the form of a bellcrank or right-angled lever, as will be clear from Fig. 8. Since one of the screw extensions 94 and its lock-nut 95 project beyond the outer surface of base plate 69, one side of the weight 63 may be provided with a groove 69 to receive the projecting parts 94 and 95, as shown in Fig. l0. This arrangement permits the weight to lie flat on top of casing 68.

Although I have illustrated and described certain specific constructions, I want it understood that my invention is not limited to the details set forth. Changes and modifications.

will doubtless suggest themselved to those skilled in the art without departing from the scope of the appended claims.

I claim as my invention:

1. A combined recording and reproducing unit comprising a vibratory member carrying a pair of separate holders projecting at a diverging angle of at least ninety degrees, a recording stylus supported in one holder and a reproducing stylus supported in the other holder the diverging relation of said styli causing them to be widely separated for easy access, and mechanism for operating said member and recording stylus in accordance with transmitted electric impulses, the operation of said member by the reproducing stylus causing said mechanism to produce electric impulses.

2. In phonographic apparatus, the combination of an arm supported on one end to swing horiz-ontally over a record, a combined recording and reproducing unit mounted on the other end of said arm, and a Weight adjustably carried by said arm and movable either over said unit during the recording operation or over the supported end of the arm during the reproducing operation.

3. In phonographic apparatus, the combination of an arm supported on one end to swing horizontally over a record, a combined recording and reproducing unit mounted on the other end of said arm, and a weight pivotally connected to said arm at an intermediate point of the arm,

whereby said weight may be swung over said unit or over the supported end of said arm.

4. In phonographic apparatus, the combination of an arm supported on one end to swing horizontally over a record, a combined recording and reproducing unit mounted on the other end of said arm, a lever hinged at one end to said arm at a distance from said casing, and a weight secured to the free end of said lever, whereby said lever may be swung forward to place the weight on top of said unit or swung rearward to place the weight on the supported end of said arm.

5. In phonographic apparatus, the combination of an arm supported on one end to swing horizontally over a record, a combined recording and reproducing unit mounted on the other end of said arm, a lever hinged at one end to said arm at a distance from said casing, a weight secured to the free end of said lever, whereby said lever may be swung forward to place the weight on top of said unit or swung rearward to place the weight on the supported end of said arm, and means for adjusting the hinge connection of said lever axially of said arm.

6. An electric phonograph reproducer comprising a U-shaped magnet, a pair of polar extensions carried by said magnet, a coil on at least one of said extensions, a vibratory support adapted to be actuated by a reproducing stylus, an armature unit carried by said support, said armature unit consisting of a pair of spaced magnetic arms arranged crosswise of said polar extensions and forming variable airgaps therewith, said bars beingA arranged on opposite sides of said coil and on opposite sides of said polar extensions.

7. A combined recording and reproducing unit,

comprising electromagnetic mechanism provided with a vibratory armature, a, recording stylus carried by said unit and mechanically connected to said armature to be operated thereby in accordance with electric impulses transmitted through said mechanism, a separate reproducing stylus carried by said unit in diverging relation to said recording stylus and mechanically connected to said armature to vibrate said armature which thereby generates current impulses in said mechanism, and means whereby said unit is adjustable to bring either stylus into operative position.

8. An electric phonograph reproducer comprising a casing, an arm pivoted to said casing, an armature carried by said arm, a stylus member for vibrating said armature, means for converting the movements of said armature into electric impulses, and elastic pads carried by said casing and engaging opposite sides of said arm in pressure contact, whereby said pads damp the movements of said arm and hold the same in predetermined normal position, said pads being located at a distance from said armature and out of contact therewith.

9. An electric phonograph reproducer comprising a casing, an arm pivoted to said casing, an armature carried by said arm, a stylus member for vibrating saidarmature, means for converting the movements of said armature into electric impulses, a pair of sockets mounted in opposite sides of said casing and adjustable toward and away from each other, and elastic pads held in said sockets and engaging opposite sides of said arm in pressure contact, whereby said pads damp the movements of said arm and hold the same in predetermined normal position, said pads being located at a distance from said armature and out of contact therewith.

10. In phonographic apparatus, a combined recording and reproducing unit comprising a vibratory member, a recording stylus and a reproducing stylus both carried by said member and extending in different directions, a support on which said unit is adjustable tobring either stylus into operative position on a record, electric mechanism for vibrating said member in accordance with transmitted impulses to actuate said recording stylus, said mechanism being adapted to convert the movements of said member by the reproducing stylus into electric impulses, and a weight adjustably mounted on said support to make the pressure on the recording stylus greater than that on the reproducing stylus.

11. A combined recording and reproducing unit comprising a casing, electromagnetic mechanism in said casing, said mechanism including a coil and an armature adapted to vibrate in accordance with current impulses passing through said coil during the recording operation, the movements of said armature during the reproducing operation generating current impulses in said coil, a vibratory member connected with said armature, and a pair of stylus members carriedby said member for recording and reproducing respectively, a movable arm on which said unit-is supported, and means whereby the supported unit is rotatably adjustable about the longitudinal axis of said arm to bring either stylus member into operative position.

12. A combined recording andA reproducing unit for disk records, said unit comprising a casing, electromagnetic mechanism in said casing, said mechanism including a coil and an armature adapted to vibrate in accordance with current impulses passing through said coil during the recording operation, the movements of said armature during the reproducing operation generating current impulses in said coil, a vibratory member pivoted at the center and connected to said armature, a recording stylus carried at one end of said member, a reproducing stylus carried at the other end of said member, said unit being adjustable to bring either stylus into operative position, a horizontally swinging arm on which said unit is operatively mounted, and a swivel connection between said unit and said arm to permit rotation of the unit through a predetermined arc for bringing either stylus into operative relation to a disk record.

13. In phonographic apparatus, the combination of a supporting arm mounted at one end to swing horizontally over a record, a casing attached to the other end of said arm and rotatable about the longitudinal axis of said arm through a lpredetermined arc to either of two operative positions, a recording stylus and a reproducing stylus projecting from said casing and each adapted to be brought into operative relation to a record by the rotary adjustment of said casing, and mechanism in said casing for operating said recording stylus in accordance with transmitted electric impulses, the movements of said reproducing stylus causing said mechanism to produce electric impulses.

14,. A combined recording and reproducing unit for operating on the same type of record, said unit comprising a casing, electromagnetic mechanism in said casing, said mechanism including an armature bar pivoted at the center and adapted to vibrate in accordance with electric impulses transmitted to said mechanism during the recording operation, the movements of said armature also causing said mechanism to produce electric impulses during the reproducing operation, a vibratory member connected intermediate between its ends to the center of said armature, a recording stylus carried at one end of said member, and a reproducing stylus carried at the other end of said member for reproducing from the same type of record on which said recording stylus operates, said casing being adjustable to bring either stylus into operative position.

15. A combined recording and reproducing unit for operating on the same type of record, said unit comprising a casing, a laterally twistable spring blade supported at its ends in said casing, a vibratory armature bar connected at the center to the center of said spring blade, electromagnetic mechanism operatively associated with said armature to vibrate the same in accordance with transmitted electric impulses, said mechanism being also adapted to produce electric impulses by the movements of said armature, an arm connected intermediate between its ends to the center of said spring blade and projecting out of said casing, a holder at each end of said arm, a recording stylus mounted in one holder, and a reproducing stylus mounted in the other holder for reproducing from the same type of record on which said recording stylus operates, said casing being adjustable to bring either stylus into operative position.

16. In phonographic apparatus, the combination of a supporting arm mounted at one end to swing horizontally over a record, a casing attached to the other end of said arm and rotatable about the longitudinal axis of said arm through a predetermined arc, a recording stylus and a reproducing stylus projecting from said casing and each adapted to be brought into operative relation to the same type of record by the rotary adjustment of said casing, `mechanism in said casing for operating said recording stylus in accordance with transmitted electric impulses, the movements of said reproducing stylus causing said mechanism to produce electric impulses from the same type of record on which said recording stylus operates, and means carried by said arm for exerting additional pressure on the recording stylus during the recording operation, said means being adjustable to remove said added pressure from the reproducing stylus.

17. In phonographic apparatus, the combination of an arm supported at one end to swing horizontally over a disk record, a casing mounted on the other end of said arm and rotatable thereon through a predetermined arc to either of two operative positions, a vibratory member carried by said casing and supported substantially at the center to vibrate laterally in either position of the casing, a stylus holder at each end of said member, a recording stylus in one holder and a reproducing stylus in the other holder, said recording stylus being in operative position when said casing is turned one way and said reproducing stylus being in operative position when the casing is turned the other way, said two styli being constructed to record on and reproduce from the same type of disk record, and mechanism in said casing for operating said vibratory member and recording stylus in accordance with transmitted electric impulses and for converting the vibrations of said reproducing stylus and member into electrical impulses.

18. In phonographic apparatus, the combination of an arm supported at one end to swing horizontally over a record, a casing mounted on the other end of said arm and rotatable: thereon through an arc of approximately 180 degrees to either of two operative positions, a vertical member arranged at the front end of said casing in alignment with said arm, means in said casing for supporting said member substantially at the center to vibrate laterally, a stylus holder at each end of said member, a recording stylus in one4 holder and a reproducing stylus in the other holder, said recording stylus being in operative position when said casing is turned one way and said reproducing stylus being in operative position when the casing is turned the other way, said two styli being constructed to record on and reproduce from the same type of record, and mechanism in said casing for operating said vibratorymember and recording stylus in accordance with transmitted electric impulses and for converting the vibrations of said lreproducing stylus and member into electrical impulses.

19. In phonographic apparatus, the combination' of an arm supported at one end to swing horizontally over a'record, a casing mounted on the other end of said arm and rotatable thereon through an arc of approximately ninety degrees to either of two operative positions, a rightangled lever pivoted at the center to said casing and projecting therethrough, a stylus holder at each end of said member, a recording stylus in one holder and a reproducing stylus in the other holder, said two styli being constructed to record on and reproduce from the same type of record, said recording stylus being in operative position whensaid casing is turned one way and said reproducing stylus being in operative position when the casing is turned the other way, a iinger in said casing connected to the pivoted center of said lever, a magnetic armature carried by said finger, and electromagnetic means for vibrating said armature and recording stylus in accordance with transmitted electric impulses, the vibrations of said armature by the reproducing stylus causing said electromagnetic -means to produce current impulses.

20. In phonographic apparatus, the combination oi' an arm supported at one end to swing horizontally over a record, a casing mounted on the other end of said arm and rotatable thereon o casing is turned one way and said reproducing stylus being in operative position when the casing is turned the other way, mechanism in said casing for operating said vibratory member and recording stylus in accordance with transmitted electric impulses and for converting the vibrations of said. reproducing stylus and member into velectrical impulses, and means carried by said arm for exerting additional pressure on the recording stylus during the recording operation, said means being adjustable to remove said added pressure from the reproducing stylus.

ADOLPH A. THOMAS.

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