US1077361A - Electrograph. - Google Patents

Description

R. S. M. MITCHELL.

ELECTROGRAPH.

APPLICATION FILED MAR. 13, 1912.

1,077,361,, Patented Nov/1, 1913.

2 SHEETSSHEET 1.

N! YYVESSES 4 UNITED STATES PATENT orriou.

Rionmn s; m. m'rcnnmz, or suna'cusn, NEW YORK, ASSIGNOR, BY Dinner AND MEsNn'AssIGNMENms; To THE TALKING MovING PICTURE 00., Inc, or'sYRAcUsE, NEW YORK,ACORPORATIO1\T or NEWYORK.

EEEEGTROGRAPH;

s ecification-oi Letters Patent; 7

Patented Nov. 45, 1913.

Application filed'March 13, 1912. Serial No. 683,593:

To all whom it may'concem Be-Pit known that I, RICHARD-S. MtMrrom Ema,-

citizew 0% the United States,- rel 1ding-at Syracuse, in the county of Onondaga and State oi? New Yorlt;- have invented? ccr-.

. able record cylinder adapted for recordingimpressions effectedby avibrating needle or stylus.

A further object is: toprovldea double screw-feeding mechanism for controlling the travel ott-he' stylus over the'sur-t'ace of said cylinder. 7 i I A further object is'to provide a sensitive resilient adjusting mechanism for regulating the pressure of the stylnsupon the cylinder.

A further object is to=provide means for readily and accurately adjusting: and settingthe stylus forstarting the recording or the reproducing of a; record at a precisepoint, and for repeatedly starting therecord from the same point;

A further object is to provide meansfor throwing and holding the'stylus out ot-engagement with; the record; cylinder, the said means being controlled by an electromag net, and wherein by the deenergizingof the said magnetthe stylus retingagesthe record cylinder at. the point fixed by the said, adjust-ment.

A further object is-to provide means assooiated with the stylusfor recording electrio-finctuations given to it by an external current, and also to reproduce an extra circuit those fluctuations in'tacsi'miile.

A1 further object isto provide means-for- =receiving at a distance the sounds of voices,

music and the'like, and thenchanging said sounds into electromagnetic vibrations which are simultaneouslyimpressed by the said stylus; upon the recordcylinder carried:

by, themaohine. I Aefurtherobjectis to. provide means for converting-1 the impressions recorded upon the record cylinder intoelectro magnetic vibrations whichcause fluctuations in a se-- ries of electric currents which operate asgraph; showing thetransmitter in. positionready' for reproducing a record. Fig; 2' is arear side elevation; showing the partsin: the same position; also showing the starting and adjusting mechanism; Fig; 3'is adiagrammatic view;-. showing the primary and secondary circuits in connection with the transmitter and receiver. Fig. 4 is. avertical; longitudinal section through the re ceiuerg; showing a plain. diaphragm and a horn for amplifying sounds. Fig. 5 is a front end elevation and part section ;-show 'ing the receiver having a diaphragm with stylus; also showing the starting mechanism held'in operative position by a magnet, the receiverbeing' tilted: for breaking the con nection between the feeding parts. Fig. 6

.is a front end elevation andpart section;

showing the transmitter in the act of reproducing the-vibrations from the record. Fig. 7 is an enlarged detail; view showing the interlocking of the starting lever with. the guide sleeve of the carriage. Fig. 8 is an enlarged detail view taken on line 88 of Fig. 7 Fig. 9 is a bottom plan view of the base of the transmitter and receiver. Fig. 101-isan enlarged detail view of one of the spring electrodes, shown. in Fig. 6. Fig. 11 is a reduced sectional viewof the transmitter; showing a plain diaphragm and a horn for receiving sound waves to be-recorded.

In the drawings, the frame of the machineconsists of three. independent sections or parts, as 2,3 and 4,; which are spaced apart, as shown. These sections support all of the working and other parts of the machine.

The bottoms of the frame sections are pro-' vided with flanges. 5, which preferably, rest upon a substantially level base, as 6, to

parts, may be secured in. any

which the. said suitable manner.

' by a similar belt 28.

7 represents a cylinder or drum, upon -'which may be telescopically mounted a record cylinder or roll 8, which may be secured to the drum by. any suitable means, but is preferably held from turning on the drum, by means of a key 9, which is received by a corresponding key way,' which is formed in the inner surface of the tube 8. The record tube 8 preferably comprises the same composite material as is usedin connection with the well-known talking-machines. The head-end of the drum 7 is pro- Vided with a circumferential flange 10, which corresponds in depth to the thickness of the cylinder 8;

11 represents a groove or recess formed in the circumferential surface of the flange 10, and the said recess is preferably disposed diametrically opposite the key 9. Under this arrangement, every record tube may be repeatedly applied to the drum 7 in exactly the same manner.

The head-end of the drum 7 is provided with a relatively long integral gudgeon or shaft 12, which passes through central bearings 13 of the spaced frame sections 2 and 3. The bearings 13 are preferably split for receiving detachable bushings 14, which are held in place by means of clamping screws 15, which pierce depending lugs 16 and 16, the lug16 being threaded in the usual man ner. The frame sections 2 and 3 are preferably spaced apart a suflicient distance to support and hold the drum 7 and the record tube in true horizontal position. The drum 7 is held in place and prevented from longitudinal movement or play by a pair of sheaves-17 and 18, which are formed integrally with concentric hubs 19, the said hubs filling the space between the frame sections 2 and 3, and are secured to the shaft 12 by means of a set-screw 20.

21 represents a stationary guide shaft or" rod, which pierces arms 22 of the frame sections 3 and 4, and the said shaft is held rigidly in place by set-screws 23.

24 and -25 represent like wormor screw shafts, which are disposed above and on each side of the drum. 7. The worm shaft 24 is revolubly mounted in arms 26 of the frame sections 2, 3 and 4; while the worm 25 is mounted in bearings arranged in the arms 22 of the said frame sections. The worms 24 and 25 are provided with fine threads preferably 100 to 200 to the inch-and the said worms are driven in the same direction, and at the same speed, by means of sheaves 27' and 28, which are mounted rigidly on said shafts, between the frame sections 2 and 3. The sheave 27 connects with the sheave 17 by means ofa flexible belt 27 the sheave 28 connects with the sheave 18 All of the said sheaves are preferably of the same diameter, so that the drum and the two worm shafts may be turned by the same power synchronously. The shaft or gudgeon 12 preferably extends beyond the frame section 2, and carries a driving sheave 29, by means of which the drum and worms maybe driven by a common power. The sheaves 27 and 28 are made fast to the worm shafts by setscrews 30.

The carriage of the machine is mounted above the drum 7 and the worms 24 and 25, and consists of a metal ring or frame 31, circular in form, within which a receiver or transmitter is disposed and carried. At the rear side, the carriage is supported by the guide shaft 21, by means of a lug 32, which may be integrally formed with the ring 31.

The lug 32 is preferably formed eccentric relatively to the ring 31, and has a sleeve 33 which is bored out to slidably fit the shaft 21, One end of the sleeve 33 is cutaway to provide a clutch-tooth 34. The

front side of the carriage is fitted with an angular bracket 35, which is secured to the carriage by screws 35'. The lower arm of the bracket 35 extends inwardly beneath the ring 31, and to its underside is secured a half nut 36, the free end of which is fashioned to fit and engage the threads of the wprm 24. The arrangement of the parts 35 and 36 is such that, the forward side of the carriage is supported, while the machine is in operation, by the worm 24. 37 represents a second half nut or chaser, which is secured" to the underside of the sleeve 33 at the rear side of the carriage, by a screw 37.

The nut 37 is inverted, as compared with the rack 36, so that when the machine is operated, the nut 37 engages the underside of the worm 25. The carriage is moved longitudinally over the drum 7 by the operation of worms 24' and 25. In practice the worms 24 and 25 and the drum 7 are only operated in one direction, as indicated by the arrows in the several views, which causes the carriage to be moved from the front to the rear end of the machine. To return the carriage to the head of the machine, which is always the starting point, the operator may take hold of the bracket 35 and lift the frame 31 until the nuts 36 and 37 and the stylus clear the worms and record' cylinder,

as shown inFig. 5. Then by sliding the parts 32-33 on the shaft 21, the carriage may be readily and quickly brought to the position shown in Figs. 1 and 2. In this way the connection between the lug 32 and the shaft 21 serves as a hinge for the car-' riage.

In carrying out thefobjects of the present stylus or needle is located with relation to the head end of the record tube 8 and the flange 10 of the drum 7. And I also provide a positive starting mechanism which will always bring the stylus carried by the carriage to the same starting point on the record cylinder 8. The starting mechanism consists of the following parts: 38 represents a depending lever or arm, the upper end of which is formed with a sleeve 39, which is journaled on the shaft 21. One end of the sleeve 39 is cut-away to provide a clutch-tooth 39, which interlocks with the tooth 34 of the sleeve 33 (see Figs. 1, 2, 5, 7 and 8). The opposite end of the sleeve 39 bears against arm 22 of the frame section 3. When the carriage 31 and the lever 38 are in the position shown in Figs. 1, 2, 5, 6, 7 and 8, the clutch- teeth 34 and 39 are interlocked, and while in this position, the carriage may be elevated or lowered by shifting the lever 38 toward or from the drum 7. The carriage may also be swung on the rod 21 independently of the lever 38, whenever desired, as indicated by the dotted lines in Fig. 8. The lower end of the lever 38 is pivoted to a plunger armature 40 of a magnet 41, by a pin 40, so that the said lever is allowed a slight lateral movement or swing, as indicated by a comparison of Fig. 5 with Fig. 6. To eflect the starting of the carriage from a definite or fixed point in relation to the drum and the'record cylinder 8, I provide a bolt 42, which pierces the lever 38 near its lower end. The bolt 42 has a head 42, which is normally held against the rear side of lever 38 by arm 43 of a bell-crank lever, which is controlled by a coil spring 44. The spring 44 tends to hold the bolt 42 in the forwardly extending pos tion shown in Fig. 6, and the said bolt is disposed directly in line with the recess or groove 11 of the flange 10.- Just before the machine is started, the operator should press the lower end of the lever 38 toward the drum 7, until the pin 42 is forced back through said lever and compresses the spring 44. At the same time the lower arm 45 of the bell crank is tilted upwardly and passes between and engages two contact clips or springs 46 and 47 carried by the magnet 41. The clip 46 is connected by a wire 48 to a battery 49; while the clip 47 is connected to one end 50 of the magnet coil; the other end of the said coil being connected with the battery by a wire 51. WVhen the arm 45 of the bell-crank engages the clips 46 and 47, it closes the circuit through the magnet 41, and the latter then draws the armature 4O inwardly, and holds the armature and also the lever 38 in the position shown in Fig. 5. At the time the lever 38 is manipulated, as described, owing to the interlocking of the clutch 3439', the carriage 31 is tilted slightly, as shown in Fig.

5, which breaks the connections between the feeding parts comprising the nuts 36 and 37, and the worms 24 and 25,.and the car'- riage will remain still. While the carriage and lever 38 are in the position shown in Fig. 5, the power may be applied to the pulley or sheave 29 for starting the rotation of the drum and worms. After the machine is started, it only requires a partial turn of the drum 7 to bring the recess 11 around to the point where the bolt 42 is pressing against the flange 10. When the recess 11 comes opposite the bolt 42, the latter being under pressure of the spring44, will shoot into the recess, thereby allowing spring 44 to relax or expand, which in turn will rock the bell-crank back to the rest or idle position shown in Fig. 6, which will break the electric connection at the clips or switch 4647 and deenergize the magnet 41. Instantly upon the breaking of the circuit the carriage will gravitate by its own Weight from the position shown in Fig. 5 to that shown in Fig. 6, and at the same time lever 38, owing to the engagement of the clutchteeth 3439,' will be forced away from the drum 7. Then, if the machine continues to operate, by reason of the meshing of the racks 3'6 and 37 with the worms 24 and 25, the carriage will be held in true horizontal position, and will be moved from the head toward the tail of the machine, at a rate of speed governed by the number and fineness of the threads of the worms. If it is necessary to stop the carriage 31 at any time before it has traveled the full length of the drum 7, this may be done by simply manipulating the lever 38 and thereby energizing the magnet 41. The power should be shut ofi at the same time that the lever 38 is operated, so as to prevent the automatic starting of the carriage, as described.

The electric and associated parts carried by the machine will now be described.

In the present device, the impressions or record which are recorded on the cylinder 8, are made in the first instance by a stylus or needle 53, which is carried by a spider or holder 54, which is soldered or otherwise I ing or nonconducting material may be used for the purpose. The diaphragm 55 is disposed between the top 57 and the base 58, as best seen in Fig. 5. A series of bolts 56 clamp and hold the sections 57 and 58 together.

g The diaphragm 55 is vibrated by the fluctuations of an electric current which i passes through a series of magnets, a, b, c and d, which connect to and depend from a steeLor iron ring 60, which is rigidly supported in a chamber 61 of the cap 57, by a of the cap 57. When the diaphragm 55 is placed in operative position in the receiver, the spider 54 and also the stylus 53 project slightly below the bottom part 58, so that when the half nuts 36 and 37 engage the worms 24 and .25, the point of the stylus 53 will be in engagement with the top surface of the record cylinder 8 (see Fig. 6). When the receiver 56 is employed for recording the vibrations on a blank record, the said receiver is placed within the circular carriage frame 31. The rear side of the receiver being secured, by one of the bolts 56 to an inwardly projecting part 65, which is pivoted or hinged to the bottom side of the frame 31 by a pin 65'. The forward or opposite side of the receiver is adjustably supported in the frame 31 by means of a bolt or rod 66, which passes through the top and bottom sections of the receiver and then upwardly through one arm of the bracket 35 and a coil spring 67, and the said spring is held in place and given the desired tension by means of a thumb-nut 67 The spring 67 imparts a slight resilience or flexibility to the forward side of the receiver and permits of a fine adjustment of the stylus or needle 53 relative to the surface of the record cylinder 8. The electric current which energizes the. magnets a, b, c

jam-nuts 70. I. next and d is supplied by a pair of wires 72 and 73, which form parts of a secondary alternatin circuit which will later be described.

Be ore a new record is made the operator should make a mark, as 68, on the record cylinder 8, opposite the recess or groove 11 in the flange 10 of the drum, the said mark is toindicate the point where the stylus 53 shall begin the record, as indicated by the threads in Figs. 1 and 2. After he has made the'mark 68, he should then adjust the carriage 31, so as to bring the point of the stylus to said mark. To adjust the carriage- 31 and receiver 56, I provide a lug 69 on the sleeve 33, throu h which a screw 69 is threaded, the said screw being locked and held in any desired position by means of rovide a similar lug 71 on the sleeve 39 0 lever 38. The inner end of screw 69' engages the lug 71, which serves as a stop for limiting the return movement of the carriage toward the head of the machine. By the use of the screw 69, the carriage may be adjusted for setting the stylus exactly on the mark 68, or many other position desired. At the time the record is made on the cylinder 8, there are no sound waves received by the diaphragm 55, and no sounds uttered at or near the receiver 56, can enter the receiver or have any efi'ectwhatever upon the diaphragm 53. Hence, no matter what sounds or noises may be made in the vicinity-of the receiver 56, no record or impression will be made upon the record cylinder 8. So far as the recording and transmitting of the record on the part 8 is concerned, the machine is entirely silent. 7 At the time the records are made, the soundsof voices, music or other noises are made at a distance from the machine. These are received by a specially constructed transmitter to which a horn is attached. ,Whatever impressions are made on the record are effected entirely by electromagnetic vibrations, produced by the fluctuations in the electric currents or cir cuits, which are received through the wires '72 and 73, and transmitted by the magnets a, b, c and d to the diaphragm 55 and then to the stylus 53, which frictionally engages the cylinder 8', and indents or otherwise formsimpressions which correspond to said vibrations.

Fig. 6 illustrates a transmitter employed for reproducing the vibrations or impressions recorded on the roll 8, which will now be described: Assuming that a record has already been made on the roll 8, as indicated by the threads 8 in Figs. 1 and 2, and that the reproduction thereof is to be cffected, I place within the circular frame 31 of the carriage a transmitter 75, which comprises a solid back or cap 76 and 'a base 77. Both of these parts are preferably made of an insulating material, such as hard rubber, fiber and the like. The parts 76 and 77 are circular, as shown. The top 76 is prefer,

ably hollow for providing a relatively large chamber 78, while the bottom 77 is provided with a shallow recess or depression 79, and a four-way slotted opening 80. Between the two sections of the transmitter is disposed a relatively large circular disk or diaphragm" 81, which may be made of steel, wood -orcomposition, so long as it is sufliciently metalicized to serve as an electromagnetic conductor. The diaphragm 81 rests upon a narrow felt or like ring 82, which is disposed beneath its edges. The said diaphragm is preferably held in place upon the felt, under the requisite amount of pressure, by a series of springs 83, which also serve as electrodes, and these are disposed at intervals around the top side of the diaphragm 81. The springs 83 are held in place and given more or less tension as desired, by means of a series of bolts 84 and nuts 84', the, upper ends of the bolts 84 serving as binding posts. To the underside of the diaphragm 81 is secured a four-arm f spider 85, similar to the part 54 of the receiver, the outer ends of said arms being.

represents a stylus or needle which is con-- nected to the spider 85 in any suitable manner. The stylus 86 is preferably similar to those employed on phonographs for reproducing the records. The spider 85 and stylus 86 preferably project slightly below the base 77, in position to readily engage the record cylinder 8, when the carriage isin the operative position shown in Figs. 1, 2 and 6. Upon the diaphragm '81 is mounted a series of hard rubber cups '87, each of which is glued or otherwise rigidly fastened to diaphragm 81, and the interior of said cups are-filled with granulated carbon 88, which rests upon the top surface of the diaphragm. The carbon 88 is subjected to a suitable pressure, by means of a series of screws or bolts 89, which are carried by the top 76, thelower end of the screws being fitted with concave cone-shaped electrodes 90, which are arranged to exert an even pressure upon the carbon in the lateral and downward directions. The upper ends of the bolts 89 comprise binding-posts and these are fitted with adjusting nuts 89 and thumb-nuts 91, between which wires 92, 93, 94 and 95 are connected. 96 represents a wire which connects in series with the hinding-posts 84 of thesprings 83. The four wires first named comprise separate primary circuits having a common return throug wire 96 to the batteries which are controlled by the transmitter 75. The transmitter 75 is disposed in the carriage 31, in exactly the same manner as the receiver 56, the rear side of the transmitter being secured to the hinge member 65, which is pivoted to the carriage by a pin The forward side of the transmitter is adjustably supported in the carriage frame 31 by a vertically arranged bolt or rod 66, which passes through the rubber parts 76 and 77 and then extends upwardly and passes through one arm of a bracket 35. The rod 66 is fitted with a coil spring 67, the lower end of which rests upon the bracket 35, while its upper end is engaged by a thumb-nut 67 by means of which any desired tension may be given to the said spring for raising or lowering the transmitter relative to the record roll 8 and also the carriage.

The circuits employed in connection with the receiver 56 and transmitter 75 will now be described.

Referring to Fig. 3 the primarycircuits.

around the coils in a separate windings, as

consist of the four direct wires, 92, 93., 94

and 95, which pass in the form of a cable 97 toa box 98, in which is disposed a series of. coils, illustrated diagrammatically at 99. Each of the four wires last referred to pass indicated, and then through batteries 92', 93,- 94' and 95 respectively. From the batteries, these four wires lead to and connect with a common return wire, which is the wire 96, and which connects in series the binding-posts 84. Under this arrangement, each of the electrodes 89 is supplied with a direct current through its own primary circuit, while the electrodes 8384 are connected with the common return wire 96. No matter whether the transmitter 7 5 is employed for transmitting the sounds to the receiver 56 for recording the corresponding electro-magnetie vibrations on a blank record cylinder, or whether it is employed for picking up the vibrations from the record and transmitting them to the receiver which reconverts the vibrations into sounds which are reproduced through a horn, aslOO, the transmitter is always directly connected to the primary circuits, as described. On the other hand, the receiver 56 is always connected with the secondary circuit, which consists of the wires 72 and 73, which as described, pass around the magnets a, b, 0 and d by means of a series winding, then to the binding-posts 63 and 64, thence to the four coils 101, where the windings are arranged in parallel. The electro-motive-force induced in the secondary coils 101, is preferably higher than the primary electro-motiveforce, although this may be varied to suit conditions.

Fig. 4 represents the receiver 56, when the electric parts are employed, .(as illustrated in Fig. 3,) for reproducing a record of the vibrations which had previously been prepared, as described. The receiver shown in Fig. '4, differs from the receiver shown in Fig. 5 in that the diaphragm 53 has been substituted by a plain diaphragm 102, which is disposed between the rubber cap 56 and a modified base 103, which is provided .With a neck 104 for receiving and supporting the amplifying horn 100. The base 103 is provided with a clear concentric opening 105 which afiords unobstructed commumcation with the diaphragm 102..

Under the'construction and arrangement of the electric circuits, as herein shown and described. both the receiving and the reproducing of the sounds may be effected at any reasonable or desired distance from the electrograp'h machine, by simply lengthening or 12 shortening the wires 72 and 73 of the secondary circuit. On the other hand, to make a new record, the transmitter 75 (see Fig.

11) is provided with a plain diaphragm 106, and a modified base 107 is substituted for the base 77 to which the horn 108 may be conof considerably "heavier gage than the dia-t phragms of the common telephone receivers and transmitters. The purpose of these modifications is to prevent, as far as possible the vibration of the diaphragms directly by any-sound waves whatever. In the present invention the diaphragm is only intended to be vibrated by the electro-magnetic fluctuations in the currentwhich act upon magnets a, b, 0 and d. The diaphragm 81 is only intended to be vibrated by the vibrations or pulsations it receives through the contact of the stylus 86 with the record cylinder 8,

At the time a new record is made, the waves of the sounds of voices, music and the like, are carried by a born, as 108, to a plain diaphragm, as 106 which is placed in the transmitter 75, for the purpose. These waves cause the diaphragm to vibrate, and the vibrations in turn cause-an increase and decrease of the pressure between the fine particles of the carbon 88, which will correspondingly increase and decrease the resistance in the said carbon, thereby simultane ously increasing and decreasing the current in the separate'circuit-s of the electrodes 90, causing the said circuits to fluctuate synchronously with the vibrations of the diaphragm. The fluctuations-of these currents in the primary coils 99 induce like fluctuations in the secondary coils 101, and are car-- ried by the wires 72-73 to the magnets a, b, c and aof the receiver 56, setting up magnetic fluctuations therein, which act upon the diaphragm armature 55, setting up in it vibrations. which are then recorded upon a suitable blank record, like 8. To reproduce the said record, the order of the electric parts is reversed The transmitter 75 is mounted in the carriage 31; and it is fitted with the diaphragm 81; having the stylus 86. The stylus 86, when brought into contact with the record cylinder 8, picks up the impressions which were recorded thereon, and

imparts them to the diaphragm 81, setting up therein vibrations or pulsations. The said vibrations or pulsations correspondingly increase and decrease. the pressure upon the granulated carbon 88 confined between said diaphragm and the cone-shaped electrodes 90. The increase and decrease of multaneously fluctuations of the magnetic circuit, whitth will set up in the plain diaphragm 102 of the receiver vibrations corresponding exactly to the vibrations set up in the diaphragm 81 of the transmitter, and

the sound Waves resulting therefrom will.

correspond absolutely to 'those received by the transmitter of the recording instrument and will be rendered audible bv the horn 100.

It is obvious that two or more receivers and horns may be connected to the electrograph, for reproducing records at as many diflerent points simultaneously, and that some changes and modifications may be made in the parts of the device, within the scope defined by the appended claims, without departing from the spirit of the invention.

Having thus described my invention, what I claim as new, and desire to secure by Let- Patent, is

1. The combination of a frame, a rotatable drum supported by said frame, said drum having a circumferential groove and adapted to support a record, a carriage reciprocable in said frame above said drum, a transmitter supported by said carriage and having a stylus adapted to engage said .rec- 0rd, a rocking lever carried by said frame, means for interlocking said lever with said carriage, said lever capable of being rocked by hand for tilting saidcarriage and transmitter away from the record and drum, for stopping the playing of the record, a magnet, said magnet having an armature connected to said lever adapted when said magnet is energized to hold said carriage in the tilted position, and a pin carried by said lever adapted to enter the groove of said drum for deenergizing said magnet for allowing said caniage to gravitate toward said drum.

2. In combination, a rotatable drum adapted to carry a cylindrical record, a carriage mounted above said drum, means for moving said carriage from the head toward the tail of the drum, a rocking lever adapted to tilt said carriage away from the record cylinder,

an electro-magnet adapted for holding said' lever and said carriage. in the tilted position, means carried by said drum, and means carried by said lever adapted to efiect the denergizing of said magnet for allowing said carriage to gravitate to the starting position. 1

3. In combination, a rotatable drum having a circumferential recess, said drum adapted to carry and operate a record, a carriage mounted above and adapted to travel along said drum, a rocking lever adapted to lift said carriage away from said drum, a reciprocating pin carried by said lever, a magnet to hold said carriage in the elevated position until said reciprocating pin engages the recess in said drum, and means controlled by said reciprocating pin for efiecting the starting of said carriage at a fixed point on the record relative to the recess in said drum.

4. In combination, a frame, a rotatable drum supported by said frame, said drum having a circumferential notch, a carriage disposed above said drum, said carriage supporting a transmitter having a stylus adapted to engage a record carried by said drum, a lever pivoted in said frame, said lever having a pin adapted to engage the notch of said drum, said lever capable of being operated by hand for lifting said carriage for breaking the engagement of said stylus with the record and for bringing said pin into engagement with said drum, a magnet for holding said carriage and stylus in the inoperative position, and means for rotating said drum so as to permit said pin to enter the notch in said drum for efii'ecting the lowering of the carriage and the engagement of the stylus with the record.

5. In an eletrograph, the combination with a frame and a rotatable drum adapted to support a record, said drum having a key for engaging a key-way in' the record, a carriage reciprocably mounted in frame, said carriage supporting a transmitter in position to engage the record, a shaft carriedby the frame upon which said carriage isslidable, a rocking lever, said lever journaled at one end on said shaft and having a clutch-portion adapted to engage a similar portion of the carriage, whereby said carriage is lifted away from the record when said lever is brought toward said drum, an electro-magnet adapted when energized to temporarily hold said lever in said operated position, and means for deenergizing said magnet for allowing said carriage to approach the record for startingthe recording or reproducing.

In testimony whereof I afiix my signature in presence of two witnesses.

RICHARD S. M. MITCHELL. Witnesses:

HARRY DE WALLACE, ETHEL M. Jones.

said-

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