US1909839A - Twin-phonograph - Google Patents

Description

May 16, 1933. J. MOTYL TWIN-PHONOGRAPH Filed May 23. 19.30

3 Sheets-Sheet l um e! May 16, 1933. J, MQTYL 1,909,839

TWIN-PHONOGRAPH Filed May 23, 1930 3 Sheets-Sheet 2 A T TORNE YS.

Patented May 16, 1933 UNITED STATES PATENT OFFICE JOSEPH MOTYL, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR T0 DICTAPHONE CORPORA- TION, OF BRIDGEPORT, CONNECTICUT, A CORPORATION 0F NEW YORK TWIN-PHONOGRAPH Application led May 23,

This invention relates to tWin-phonographs for reproducing lengthy speeches, telephone conversations and the like; and more particularly to means for controlling the alternate operation of the units thereof.

One of the objects thereof is to provide a simple and practical machine of the character described.

Another object is to provide simple means in a machine of the above nature for preventing a hiatus occurring in the matter recorded or reproduced.

Another object is to provide effective automatic means for causing the alternate operation of the twin units of the phonograph in such a way as to ensure a predetermined degree of repetition of matter recorded or reproduced as one unit becon'ies inoperative and the other unit comes into action.

Another object is to provide a compact and highly efficient arrangement of the duplicate units of a twin-phonograph.

Another object is to provide such a phono graph in which all movements, mechanical and manual, which take place in the operation of one unit, are duplicated with respect to the other unit and take place in the same direction.

Another object is to provide practical clutch-operating mechanism for a machine of the nature described the action of which Will be controlled automatically by the carriages of the respective units, during their normal operation.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, comliinationsvofclef ments, and arrangements. of parts as will be exemplified in the structure to be hereinafter described and the scope of the application 0f which will ybe indicated in theV following claims. Y s Y v. Y

In the accompanying drawings in Iwhich is shown one of the various possibleem-v bodiments of my invention Y c f Figure 'r1 is a `top planY view of a twinphonograph embodying the present inven tion.

Figure 2 is a front elevation showing one 1930. Serial No. 454,900.

of the phonograph units operative, with its carriage approaching the end of the recordcylinder.

Figure 3 is an elevation of the twin-phonograph, showing the driving motor and mechanism.

Figure 4 is a front elevation similar to Figure 2, but also shows the driving motor, he main clutch and operating means there- Figure 5 is an end view of both of the phonograph units, partly in section, showing the driving arrangement between the mandrel shaft and the feed screw, the control for the recording stylus and the feed nut, and the common mechanism for shifting the individual phonograph clutches.

Figures 6 to 9 inclusive are schematic views showing the mechanism for operating the twin-phonograph clutches in the various positions assumed by said mechanism during the operation of one unit of the machine.

Figures l0 to 18 inclusive are schematic views similar to the Figures 6 to 9 inclusive, showing the various positions of the clutchoperating mechanism during the operation of the other unit of the machine.

Before describing the present twin-phonograph in detail it may be Well to give consideration to certain of its more general aspects. It will be understood that this type of machine has its principal use when it is desired to record or reproduce continuously matter of too great length for its inclusion Within the lim'its of a single record tablet. Accordingly two duplicate phonograph units are,employed..eachhavingQa mandrelfor Sup;

pt )rtingl a, krecord tablet,-eachr'mandrelllbeing til the end of the speech or message or so long as the operator desires.

The present invention provides a novel arrangement of mechanical elements automatically to actuate the clutch of the second phonograph unit to initiate its operation when the stylus of the first unit approaches the end of its record cylinder, and subsequently to disengage the clutch of said first unit. Then automatically to actuate the clutch of the first unit to initiate its operation when the stylus of the second unit approaches the end of its record cylinder, and subsequently to disengage the clutch of said second unit.

The twin-phonograph shown in the present drawings comprises a sub-base 20 which is hinged or similarly mounted on a box (not shown). Upon the sub-base, suitably secured side by side by screws 21, are a pair of frames 22 for duplicate phonograph units, hereinafter referred to as unit A and unit B. In the general description, it should be understood that the details described in one unit are exactly duplicated in the second unit. Each of the frames 22 comprises an integral housingr 24 which provides a suitable bearing 25 for a mandrel shaft 26 upon the right-hand end of which there is mounted a mandrel 27 and upon the left-hand end of which there is mounted'a freely rotatable pulley. T he mandrel is adapted removably to support a record cylinder 29 of wax-like material, upon which a helical sound groove is engraved by meansof a recording stylus in a well-known manner.

Near the right end of the frame 22 are a front standard 30 and a back standard 31. Between these standards and the housino' 24, there is supported a front carriage rod 32, a back carriage rod 33, and a rotatable feed screw 34. Upon the rods 32 and 33, and adapted to be moved longitudinally of the record cylinder 29, is a sound-box carriage 35 'which supports an electric recording device or sound-box 36 of any suitable construction.

By referring to Figure 5 which shows an end view of the phonograph units, partly in section, it will be seen that a pinion 37 on the mandrel shaft engages an intermediate gear 38 and a feed screw gear 39 to rotate the feed screw. A control lever 40 is rotatabl mounted in the carria e on a sleeve 41. hen this lever is raise the lobe 42 enga es a portion of the feed nut 43 and lifts the eed nut out of engagement with feed screw 34, at the same time the lobe 44 ^f lever 40 engages the ivotally mounted stylus carrier 45 to lift t e stylus 46'out of engagement with the record cylinder 29. In the normal operation of the machine, the sound-box carriage is initially at the farthest left-hand position as shown in unit B, Figure 1, and the control lever is lowered so that the recording stylus is in engagement with the record cylinder, the feed nut being yieldingly held in engagement with the feed screw, by means of spring 28, as in Figure 5.

In its present preferred form, the prime mover and drive arrangement for the twinphonograph comprises an electric motor 47 suitably suspended on vibration absorbing connections 48 to the underside of the subbase 20, as may be best seen in Figures 3 and 4. The outer left-hand end of the motor armature shaft 49 supports a main driving pulley 50, freely rotatable between the collars 51 and 52 which are held in fiiied relation to the armature shaft in any desired manner, and the right-hand side of this pulley is provided with a flange 53 carrying clutch pins 54. vAn idler pulley 55 is rotatably mounted upon a stud 56 which projects from a boss 57 formed upon the motor casing. A sin le driving belt 58, see Figure 3, runs from t e main pulley 50 in the direction of the arow to the pulley 59 of unit B and from this pulley to the idler pulley 55, then to the pulley 60 of unit A, and finally back to the main driving pulley. Thus, when the main driving pulley is rotated, it simultaneously effects rotation of the pulleys 60 and 59 of units A and B respectively.

The machine is normally used to record telephonie conversations or public speeches, and as it is often desired to record only certain portions of a conversationor speech, a clutch is provided to connect the driving motor 47 with the main pulley 50. This comprises a sliding collar 61 splined to the motor armature shaft 'and provided with pins 62 adapted to be brought into interlocking engagement with the pins 54 of the pulley 50. A bracket 63 is affixed to the motor casing by screws` 64, and provides av suitable pivotal support 65 for a bell crank 66 upon the upper end of which there is an integral armature 67, and upon the lower end of which there is formed a yoke 68 with pins 69 which enter a grooved portion 70 of the sliding collar, to move it axially along the motor shaft. A spring 71 is fastened at one end to the bell crank and at its other end to the motor casing to yieldingly maintain the clutch collar in the inoperative position shown in Figure 4. When the operator desires to connect the driving Imeans, the electromagnet 72 is energized, as hereinafter described, to attract the armature on the bell crank and to swing the bell crank about its pivot. The collar is moved to the left, as viewed in Figure 4, until the pins 62 of the sliding collar are in operative engagement with the pins 54 on the main pulley flange, when the main pulley assumes the rotation of the motor shaft. When the electric magnet is de-energized, the spring 71 retracts the bell crank and disengages the clutch members.

The Wiring arrangement for the driving motor and electric clutch control is schematically shown in Figure 4, and comprises a main feed line 73 connected to any suitable source of power supply. When a double throw'switch 74 is closed, the current flows through the wires 75 and 76 to the electric motor to cause it to rotate. A wire 77 connected to the motor feed wire 75 leads to one side of the electromagnet 72. Another wire 78 connected to the motor feed line 73 through a suitable switch 79 completes the magnet circuit. With this arrangement, the electromagnet clutch control is operable only when the electric driving motor is energized, the switch 79 enabling the operator to effect a drivin connection between the electric motor an the phonograph pulleys at will.

Having pointed out the general features of construction of the twin-phonograph units, certain novel features of the present invention will now be described.

Each phonograph unit is provided with a clutch 81 comprising a toothed hub 82 on its respective freely rotating pulley 59 or 60, and a single-toothed disc 83 at the left-hand end of a rod 83 which is longitudinally slidable in an axial bore in the mandrel shaft 26 to a point within the housing where it is connected by means of a pin 85 extending transversely through the collar and through a longitudinal slot 85 provided therefor in the mandrel shaft, to a clutch-shifting collar 84 which is slidable on the mandrel shaft. A clutch-shifting yoke lever 86, see Figure 2, is pivotally mounted on a stud 87 within the housing 24 and is provided at its u per end with pins 88 which lit in a recesse portion 89 of the sliding collar, and at its lower end is suitably connected to means hereinafter described, for swinging said lever on the stud 87 to control the operation of the clutch.

When the yoke lever 86 is moved fin a clockwise direction, it moves the@ collar 84,f

rod 83 and clutch disc 83 to the right from the inoperative position show n in unit B, Figure 1, to the operative position in engagement with the toothed hub 82, shown in unit A, Figure 1, causing rotation of the mandrel 27 and interconnected feed screw 34 of the A unit. Similarly, when the yoke lever is swung in a counter-clockwise direction the clutch disc 83 is moved from the clutched or operative position shown in unit A, Figure 1, to the left into the declutched or inoperative position, shown in unit B, Figure 1.

For the purpose of controlling the operation of the two duplicate clutch-shifting yokes, there is provided a lever system which is preferably mounted to the under side of the bases of the duplicate frames 22. This lever system shown structurally in Figures 1, 2 and 5 comprises a link 90 longitudinally movable on the under side of unit A and connected at its left-hand end by means of spring 92 to the lower end of the yoke lever` 86 which passes through a slot 91 provided in said link to permit relative movement of said parts. A corresponding Ilink 93 is similaily disposed on the under side of the honograph' unit B and is connected 1n like manner to the clutch-shifting yoke lever of the second unit.

The unit A link is connected by means of a stud 94 to a lower lever 95, extending transversely of the machine, which is (pivotally mounted on a stud 96 on the un er side of the A unit frame. This rovided at its rear end with a stud igures 1 and 5, extending u wardly a clearance slot 97 in the rame of the unit. A collar 98, with a tooth 99, having an lar sides 100 and 101, is adjustably allixe to the stud 97 b the lock screw 102 just above the top sur ace of the base of the frame, and this tooth 99 is adapted to be in yielding enga ement at all times with a spring detent 103 iaving angular sides 104 and 105, the said detent being aixed to the top side of the frame by means of a bracket 106 secured to the frame by screws 106.

he spring detent just described serves lever is 97, see through yieldingly to maintain the clutch of the phonograph unit A in either the operative or inoperative position. If the operator manually grasps the stud 97 and moves it to the left from the position shown in Figures 1 and 6, the lever 95 is moved in a counterclockwise direction about the stud 96, pulling the link 90 to the right and swinging the clutch-shifting yoke lever 86 in a counterclockwise direction. The collar 84, rod 83', and clutch disc 83 of the A unit is thus forced to the left into a declutched position similar to the illustrated position of the like clutch disc of unit B. The tooth 99 will then rest against the angular side of the spring detent 103 and will yieldingly maintain the clutch of unit A in its normally declutched position.

The link 93 of the second unit B, is similarly connected by a stud 107 to an upper lever 107 which is pivotally mounted on the stud 96 above the lever 95 and is provided with a stud 108 at its forward end, which extends upwardly through a clearance opening 108 rovided therefor in the base of frame 22 of p onograph unit A. This stud 108, like the stud 97, is rovided with an adjustable collar 109 ailixe thereto by a lock screw 110, which collar is provided with a tooth 111 having angular sides 112 and 113, see Figures 1 and 7, which are adapted to engage a spring detent 114 provided with angular sides 115 and 116, see Figure 8, and which is suitably ailixed to the top of the frame of the A unit by means phonograph, or

of a bracket 117 and screws 118. These studs 130 108 and 97 are sufficiently long to be respectively in the ath of a part 11971 of the carriage of the i unit and a part 119?) of the carriage of the B unit, for purposes hereinafter set forth. Of particular importance, although not clearly shown due to its underlying the spring detent 114 and collar 109 in Figure 1. the lower lever 95 is provided with a small upstanding stud 120 which extends upwardly through a suitably shaped aperture 121 in the upper lever for the purpose of automatically shifting the clutch control lever and link for unit B when the carriage of unit A approaches the end of its travel and vice versa, in a manner hereinafter described.

The operation of the clutch-shifting lever system j ust described will be best understood by reference to the schematic views, Figures 6 to 13 inclusive, wherein parts of the complete lever system are shown in various conditions of operation. In the schematic views, like reference numerals are applied to the levers and links as indicate these parts in Figures 1, 2 and 5.

Operation of the twin-phonograph embodying the present invention is as follows:

Record cylinder blanks 29 are placed upon the mandrels of phonograph units A and B, the sound-box carriages are moved to the left-hand position, similar to the position of the carriage in the showing of unit B, Figure 1, then the control levers 4'0 of both units are manipulated to permit the styli to engage their respective record cylinders and the feed nuts to engage their respective feed screws. The sound-boxes and carriages of both units are now in condition to operate whenever the respective mandrels are set in motion.

No means for transmitting sound waves to the sound-boxes is shown, because the twin machine may be variously used; for example, the sound-boxes may be connected by electrical wiring to an amplifier and then to an electric transmitter or microphone, which serves the purpose of picking up public speeches or dictation of an executive at some remote location; that is, with the twin recording unit at a more convenient place than the sound source. The unit may also be used for the purpose of recording telephone conversation and messages. Therefore, it should be understood that the sound-boxes may be of any suitable construction designed for electric recording, and may be connected by any suitable means to divers sound sources.

After the sound-boxes are in starting position and properly conditioned for recording, the stud 97 on the lever 95 is moved about the pivot stud 96 in a clockwise direction, thereby moving clutch 81 of the unit A into an operative condition, as shown in Figure 1.

When the record cylinders are on the mandrels and the sound-box carriages in the osition and condition just described, and when the clutch control lever system is in the position shown in Figures 1 and 6, the phonograph units are in proper condition for recording. Thereafter, when the operator desires to use the twin machines for the purse of recording, it is merely necessary to close the motor control switch 74 to start the prime mover, and close the switch 79 to start mandrel rotation; viz, when the operator closes the switch 79, the pin clutch 61 is closed, causing the driving belt 58 to travel under the influence of the electric driving motor to rotate the pulley 60 of the phonograph unit A to drive or rotate the related mandrel and record cylinder. While the record cylinder of this phonograph unit rotates, the sound-box will travel over the record cylinder to cut a spiral sound groove, under the infiuence of the rotating feed screw.

Hereinafter, it should be particularly noted how the machine functions to make possible a continuous record of a telephone conversation, public speech, etc. The soundbox carriage 35 of the phonograph unit A as it travels toward the end of the record cylinder approaches the outer end of the record cylinder, as shown in Figure 1, the carriage supporting arm 119a engages the upstanding stud 108, as shown in Figure 6, and moves the stud to the right, or in the direction of the arrow shown in this figure. The carriage still continues to travel after these two parts engage and the upper lever 107 supporting the stud 108 is moved in a counterclockwise direction about the pivot stud 96 until the side of the aperture 121 engages the stud 120 of the lower lever 95 to move this latter lever in a counter-clockwise direction, as shown in Figure 7. In this portion of the pivotal movement, the upper lever, due to its connection with` the link 93 and clutchshifting yoke lever 86 causes the clutch disc 83 of the phonograph unit B to move toward its clutch collar 82. Upon further movement of the carriage of phonograph unit A, the upper and lower levers 107 and 9.5 respectively, are given a further counterclockwise movement until the tooth 111 of the collar 109 is moved to the right and beyond the high point of the spring detent 114. During this movement the link 93 is moved in a left-hand direction to move the clutch disc 83 of unit B into engaged position, starting rotation of the mandrel of the B unit, which now commences to record.

The parts of the lever system are now in the condition shown in Figure 8 and it will be apparent that the carriage of the phonograph unit A is still operative because its clutch is still in operative engagement. During a short ensuing interval the stylus of phonograph unit A and the stylus of phonograph unit B are both in operative engagement with their record cylinders, and this interval is of predetermined length. Upon further travel of the sound-box carriage in phonograph unit A, the levers 95 and 107 are moved further in a counterclockwise direction, causing the tooth 99 to ride over the high point of the spring detent 103. With the snap action then ensuing the lever 95 is given a quick counter-clockwise movement to the position shown in Figure 9, which movement is imparted to the link 90 and clutch-shifting yo e lever 86 of the A unit and quickly moves the clutch disc 83 of that unit out of operative engagement with its clutch collar 82, sto ping operation of the A unit, while the p onograph unit B continues to record.

During this continued operation of phonograph unit B the operator has ample opportunity to remove the finished cylinder rom phonograph unit A, replacing the same with a new one. To so recondition the first phonograph unit, the operatorl moves the control lever 40 (best shown in Figure 5) in a clockwise direction, to rotate the feed nut structure in a clockwise direction about its pivot pin until the halfnut portion is out of operative engagement with the feed screw; at the same time the stylus is moved out of engagement with the record cylinder. The o erator then moves the sound-box carriage ack to the starting position, that is, to the position occupied by the carriage of the B unit in Figure 1. The finished cylinder is now removed and a new one placed upon the A unit mandrel, the control lever 40 is moved to permit the stylus to engage the record and the feed nut to move into operative engagement with the feed screw.

As the sound-box carriage of phonograph unit B approaches the outer end of its record cylinder, or approaches the end of its working travel, it engages the upstanding stud 97 as shown in Figure 10 and thereafter causes the lower lever 95 to move in a clockwise direction about the pivot 96, the tooth 99 working against the angular side 105 of the spring detent 103. After the said tooth rides over the high point of the spring detent, the osition shown in Figure 11, and snaps to t e position shown in Figure 12, it moves the link 90 in a left-hand direction to cause engagement of the clutch disc 83 with its co-o erating member 82 and thereby again sets p onograph unit A in operation. Thereafter, for a predetermined length of time, both phonograph units are in operative engagement with respect to their related cerord cylinders, as described above.

The continued travel of the sound-box carriage of unit B moves the lower lever 95 further in a clockwise direction causing the stud 120, which has engaged the left-hand side of the aperture 121 of the upper Alever 107, to move the upper lever about the pivot 96 in a clockwise direction, and force the tooth 111 over the high point of the spring detent 114, when it snaps to the position shown in Figure 13. When the snap-ofi occurs, the upper lever 107 quickly com letes its movement in a clockwise direction a out the pivot 96, moving the link 93 to the right to disengage the co-operating parts of the clutch of unit B, stopping the mandrel rotation and carriage feed of the phonograph unit B. Thereafter, the operator mayy remove the filled record cylinder and recondition unit B in the same manner as hereinbefore described for 'reconditioning phonograph unit A.

This overlapping feature described for the two phonograph units is articularly desirable when recording lengtliiy telephone conversations, etc., for there would be a real disadvantage if there were an instantaneous transfer of recording action from one to the other cylinder because of the very probable break in the middle of a word or phrase, and it further enables the transcriber to determine the proper sequence of cylinders (or relationship of cylinders) because the first few words of one cylinder will correspond exactly with the last few words of the preceding cylinder.

It should be particularly noted that a twinphonograph made in accordance with the present invention has its two units arranged side by side, with their mandrel shafts parallel, and in the same horizontal plane. As with this arrangement the removal of both records from their mandrels is in the same direction, namely, to the right of the operator, and the return movements of 'the carriages are also in the same direction, namely, to the left of the o erator, the operation of the twin-phonograph is greatly simplified, completel eliminating all possibility of the operator ecoming confused in the manipulation of the machine. Thus the machine may be more effectively and accurately operated than twin-phonographs arranged with their mandrels in ce-axial alinement and extending in opposite directions. With such machines the sound-box carria es must travel in opposite Vdirections both w ile recording and when being moved to their initial positions, and, similarly, record cylinders must be removed from their respective mandrels in opposite directions.

Also, applicants mechanical clutch-switching mechanism has many positive advantages over such electrical clutch-switching mechanisms as have heretofore been suggested, by the elimination of a large number of electrical contacts, magnets, feed wires, lural motors, etc. It also ensures dependab e operation over long periods of time, since when once adjusted, there is practically no part/of co-acting members,

the mechanism subject to breakdown or disarrangement.

I claim as my invention:

1. In a device of the class described, the combination with two record holders for cylindrical records, said holders being mounted adjacent and parallel to each other, of an independent sound-box support for each holder, both adapted to travel in the same direction to record, a sound-box carried by each support, independent means for effecting operation of each of said holders and its associated sound-box support, means actuated b one of said supports when the sound-box tiiereon approaches the end of a record to actuate one of said independent means and set the other record holder and sound-box in recording operation, and means actuated by said one sound-box support after a predetermined interval to actuate the other of said independent means to stop the recording operation of said first record holder and sound box.

2. In a device of the class described, the combination with two record holders for cylindrical records, of an independent soundbox support for each holder, a sound-box carried by each support and adapted to move along lts respective record holder to record, independent means for effecting operation of each of said holders and its associated sound-box support, and a pair of coactmg members both of which are actuated successively by either support when the sound-box thereon approaches the end of a record, first to actuate one of said independent means and set the other record holder and soundbox in recording operation, and then to actuate said other independent means to render said rst operating record holder and soundbox inoperative.

3. In a device of the class described, the combination with two record holders for cylindrical records, said holders being mounted ad'acent and parallel to each other, of an in e endent sound-box support for each holder, oth adapted to travel in the same direction to record, a sound-box carried by each support, independent means for electing operation of each of said holders and its assoclated sound-box support, and a pair of one of which is actuated by one support when the sound-box thereon approaches the end of a record to actuate one of said independent means and set the other record holder and sound-box in recording operation, the other of said co-acting members being actuated by said one support after apredetermined interval to actuate the other o said independent means to stop the recording o eration of said Iirst record holder and soun -box.

4. In a device of the class described, the combination with two record holders for cylindrical recordsI said holders being mounted adjacent and parallel to each other, of an independent sound-box support for each holder, both adapted to travel in the same direction to record, a sound-box carried by each support, independent means for effecting operation of each of said holders and its associated sound-box support, and a pair of co-acting members, each of which is actuated by one support when the sound-box thereon approaches the end of a record to actuate one of said independent'means and set the other record holder and sound-box in recording operation, each of said pair of co-acting means being adapted to produce movement of the other thereof after aninterval of time to actuate the other of said independent means to render the first operating recording members inoperative.

5. The combination of two duplicate successively operated sound recording machines, each comprisin a record support and a sound-box carriage, said machines being mounted side by side whereby corresponding operations of both take place in the same direction, and means comprising a pair of yieldingly restrained members, one of which is adapted to be actuated by the sound-box support of one of said machines to stop its operation, and the other of which is adapted to be actuated by the sound-box support o the other of said machines to stop its operation, and means co-operating with said pair of members to start the operation of the after-operated machine prior to stopping the operation of the first-operated machine.

6. The combination of a air of duplicate sound recording or repro ucing machines and mechanical means comprising a spring detent member controlled by the operation of one of said machines for starting the operation of the other machine, and subsequently stopping the operation of the first-operated machine, mechanical means comprising a spring detent member controlled b the op eration of the other of said mac ines for restarting the operation of said iirst-operated machine and subsequently stopping the operation o the second-operated machine, and means connecting said two mechanicalmeans in a co-operative manner.

7 The combination with two sound recording machines each having a record support connected to a source of power by an engageable and disengageable clutch, of a pair of levers, one operatively connected with the clutch of one machine and the other operatively connected with the clutch of the other machine, a. sound-box carriage on one machine engageable with one of said levers to cause engagement of the clutch of the other machine, a sound-box carriage on the other machine engageable with the other of said levers to cause engagement of the clutch of the said one machine, and means actuating said levers each to move the other when the carriage of one machine has moved its co-acting lever a predetermined distance, thereby to disengage the clutch of that machine.

8. The combination with two sound recording machines each having a record support connected to a source of power by an engageable and disengageable clutch, of a pair of levers, one operatively connected with the clutch of one machine and the other operatively connected with the clutch of the other machine, a sound-box ca rriago on one machine engageable with one of said levers to cause engagement of the clutch of the other machine, a sound-box carriage on the other machine engageable with the other of said levers to cause engagement of the clutch of the said one machine, means actuating said levers each to move the other when the carriage of one machine has moved its co-acting lever a predetermined distance, thereby to disengage the clutch of that machine, and means for determining the said predetermined distance.

9. The combination with two sound recording machines each having a record support connected to a source of power by an engageable and disengageable clutch, of a pair of levers, one operatively connected with the clutch of one machine and the other operatively connected with the clutch of the other nachine, a sound-box carriage on one machine engageable with one of said levers to cause engagement of the clutch of the other Inachine, a sound-box carriage on the other machine engageable with the other of said levers to cause engagement of the clutch of the said one machine, means actuating said levers each to move the other when the carriage of one machine has moved its co-acting lever a predetermined distance, thereby to disengage the clutch of that machine, and adjustable means for determining the said predetermined distance.

10. In a device of the class described, the combination with two record holders for cylindrical records, said holders being mounted adjacent and parallel to each other, of an independent sound-box support for each holder, both adapted to travel in the same direction to record, a sound-box carried by each support, independent means for effecting operation of each of said holders and its associated sound-box support, a pair of coacting members, each of which is actuated by one support when the sound-box thereon approaches the end of a record to actuate one' of said independent means and set the other record holder and sound-box in recording operation, each of said pair of coacting means being adapted to produce movement of the other thereof after an interval of time to actuate the other of said independent' means to render the first operating recording members inoperative, and resilient means for completing the movement of each of said coacting means.

11. The combination of a pair of duplicate sound recording or reproducing machines andvmechanical means com rising a spring detent member controlledp by the operation of one of said machines for starting the operation of the other machine, and su sequently stopping the operation of the first-operated machine, mechanical means comprising a spring detent member controlled by the operation of the other of said machines for restarting the operation of said first-operated machine and subsequently stopping the operation of the second-operated machine, and means connecting said two mechanical means in a cooperative manner, each of said mechanical means having an adjustable part cooperating with its spring detent member.

12. The combination with two sound recording machines each having a record support connected to a source of power by an engageable and disengageable clutch, of a pair of levers, one operatively connected with the clutch of one machine and the other operatively connected with the clutch of the other machine, a sound-box carriage on one machine engageable with one of said levers to cause engagement of the clutch of the other machine, a sound-box carriage on the other machine engageable with the other of said levers to cause engagement of the clutch of the said one machine, means actuating said levers each to move the other when the car riage of one machine has moved its coacting lever a predetermined dist-ance, thereby to disengage the clutch of that machine, and a resilient snap-over device for determining the said predetermined distance.

In testimony whereof, I have signed my name to this specification this 20th day of May, 1930.

JOSEPH MOTYL.

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