US1241887A - Speed-regulator for phonographs. - Google Patents

Description

ALRUCKGABER.

SPEED REGULATOR FOR PHONOGRAPHS.

APPLICATION FILED Aue.31. 1915.

1,241,887. Patented Oct. 2,1917.

ll V. j 2 SHEETSSHEET l.

A. RUCKGABER.

SPEED REGULATOR FOR PHONOGRAPH S APPLICATION FILED AUG-3|. 1915.

1,241,887. 7 Patented Oct. 2, 1917.

2 SHEETS-SHEET 2.

l llllllllllll l l I 1 |||||1|||||||||1| ALBERT RUCKGABER, OF BROOKLYN, NEW YORK.

SPEED-REGULATOR F03 PHBNOGRAPHS.

Specification of Letters Patent.

Patented Oct. 2, 1917.

Application filed August 31, 1915. Serial No. 48,146.

T all "whom it may concern:

Be it known that 1, ALBERT RUCKGABER, a citizen of the United States, and a resident of Brooklyn, in the county of Kings, city and State of New York, have invented certain new and useful Improvements in Speed- Regulators for Phonographs, of which the following is a specification.

This invention relates to phonographs and more particularly to improvements therein, the object, of which is to provide means for the regulation of the speed of the record disk. More particularly the object of the present invention is to provide improvements over certain structures for which I filed patentapplications on March 6. 191% under Serial No. 822,933 and on August 7. 191 under Serial No. 855,618..

The invention of this application is shown in the drawings and will be more fully described hereinafter and finally pointed out in the claims.

In the accompanying drawing,

Figure 1 is a side view with parts partly in section and partly in elevation, showing my improvements embodied in a phonograph, 4 I r Fig.2 is also a side view showing parts partly in section and partly in elevation. of a diiferent form of my invention,

Fig. 3 is a diagrammatic view of the electrical connections shown in Fig. 1,

Fig. i is a side view showing partly in section and partly in elevation, of still a different embodiment ofiny invention, and

Fig. 5 is a plan view of one embodiment of the coil used on the disk.

Similar reference numerals indicate corresponding parts throughout the figures of the d rawing.

Referring to the drawings and more particularly to Figs. 1 and '2. the phonograph frame '10 has arranged therein in the usual manner the spring motor 11, which is provided with the gear 12 meshing with the pinion 13 on a shaft 14:, having secured thereto the gear 15 meshing with the bevel gear 16 on the shaft 17, to which shaft the record disk table 18 supporting the record disk 19 is secured, as clearly shown in Fi 1. The shaft 17 has a gear 20 meshing with the pinion 21 secured to a vertical shaft 22, and has its upper end 23 in a bearing support :24 and its lower end secured to a rotatable supporting plate or frame 25. Lhis support 25 is embraced by a magnet 52% as clearly shown in Fig. 1, which magnet is secured to the bracket 27 which in turn is keyed or secured to the vertical shaft 28 by means of the thumb screw or other suitable connection The shaft 28 extends vertically upwardly and passes through the tonearm 30, and has pivoted at its upper end the lever 31 having the handle 32 which is adapted to engage the locking member 33 secured to the tone-arm 30. This lever 31 is adapted to engage also the locking memher 3% on a stationary upright 35. The tone-arm is provided with the sound box 36 of any suitable construction, and this has the stylus 37 of the usual type.

Corresponding parts to those just describedare also shown in the embodiment shown in Fig. 2. with the difference, however, that to the pinion 13 is secured the horizontal shaft it) which has secured thereto the gear l1 which meshes with the pinion 42 on the shaft 43. to which is secured the gear it. This gear 'f-l' meshes with the gear 45 which acts as an idler, and this idler 45 meshes with the pinion 46 secured to a shaft 47 to which is secured the bevel gear 48 which meshes with the bevel gear l9 secured to the shaft 50. The shaft 50 is provided with a ball governor of the usual type. It is, however. quite clear that the gears 4A and 46 may be so constructedas to have a direct mesh, in which case the idler 45 need not be used. To the shaft 43 to which the gear is secured. there is secured a plate 52 supporting magnets 53 which embrace a metallic disk 5+. constituting a magnetic coupling. To the coupling member 5i is secured a small shaft to which is secured the bevel car 56 which meshes with the bevel gear 54. which corresponds to the bevel gear 16 of Fig. 1. and which is secured to the upright shaft 17, which is like the shaft 1.? of Fig. 1, and to which shaft the record disk table 18 is secured, which is like the record disk table in Fig. 1.

In my applications heretofore referred to, the stylus follows freely the groove of the record disk. This method is not used in all cases. Sometimes the stylus and tone arm are moved over the record disk by the operation of suitable mechanism. In this last named one revolution of the record disk brings about a movement of the stylus a distance corresponding to the radial distance between two grooves irrespective of what the speed of the record disk happens to be. In such cases, it it is desired to relieve the stylus of the work of moving the tone-arm and the control magnet, the tone-arm and magnet are driven by means of driving mechanism so arranged as to keep the stylus exactly over the groove of the record disk at all points and synchronous. Such a mechanism is shown in Fig. 1, and is operated by providing the shaft ll with, a pinion 60 meshing with a gear 61 having secured thereto a shaft 62 to which is secured a pinion (33 meshing in turn with. the gear (54: secured to a shaft 66 having a pinion 65, in turn meshing with the gear 67 having secured thereto the shaft 68, to the other end of which a worm 69 is secured, which meshes with the worm gear 70, secured to the sleeve-shaft 71. On the shaft. 71 slides one clutch member 72 which is adapted to engage with a fixed clutch member 73, which is fixedly secured to a tube H which is secured to the tone-arm 30 and movable therewith. The clutch member 72 is embraced by a volrc 75 pivoted at 76, having a handle 77, which handle enables the clutch member 72 to be raised or lowered into or out of engagement with the clutch member 78. When the clutch member 72 engages the clutch member Y3, positive connection is made between the spring motor and the tone-arm by the train of mechanism described, and with each revolution of the record disk the stylus 37 is moved a certain distance corresponding to the space between the grooves. Assuming that the stylus moves inward, that the driving-train speed is correctly computed and that the stylus is placed at the commencement of the outermost groove, then on the rotation of the record disk, the stylus will be moved by the mechanism inward a space correspond ing to the distance between the grooves at each revolution of the record dish. Gr. in other words, after the stylus is once placed in the groove, the stylus will always track the groove.

The train of mechanism described to connect the spring motor with the tone-arm so as to carry this out, is also clearly shown in Fig. 2, and in this case the shaft 5.? has an extension 55 having secured thereto a gear 60 meshing with a gear (31 secured to the shaft 62.

When it is'desired to use the stylus and record disk in. a manner so that the stylus follows the groove, as in the well-known Victor type, then. the yoke 75 is operated by the handle 77 and the clutch member 72 is moved. out of engagement with the clutch member '23. ll hen the clutch member 72' is brought out of engagement with the clutch member Y8 by means of the handle 7?, then the tone-arm. can move freely over the record.

When it is desired to use the device for a constant linear velocity, then the lever 31 or the lever 31 is brought into the position as shown in Figs. 1 and 2, namely, it locks with the locking member 33, and the magnet moves with the tone-arm. If the clutch members 72 and 73 are brought into engagement with each other, then a direct driving action would exist between the spring motor and the tone-arm. But when it is desired to use a constant speed record, then the lever 31 or the lever 31 is moved out of engagement with the locking member 83 and brought into engagement with the stationary locking catch ill or the catch 3& In the latter case, the magnet 26 would be locked in a permanent position. And when it is desired to have the record line drive the stylus, the clutch members 72 and 7 3 are disengaged from each other.

In order to regulate the speed of the record disk, means are provided which utilize the action of a relay, as clearly shown in Fig. 1, the electrical connection of the relay being shown in a diagrammatic manner in Fig. 3 for greater clearness. In Fig. 5 is shown one embodiment of a coil used on the disk, and for generating an clectromotivc force. The disk or frame in this case, is provided with a series of coils 80. suitably wound to act as an armature, which have their ends 81 secured. to a coi'i'ulnitator having brushes S3 and Si contacting therewith. The brush 84 has secured thereto a conductor 85, which conductor is in electrical contact with the spiral spring 87 which has its end in electrical contact with one end of the winding 88 and the other end of this winding or movable coil 88 is electrically connected with a similar spiral spring which. is electrically connected with the end of a conductor which has in series there with a resistance 90, and which. conductor is connected with the brush The winding or movable coil 88 is movable over a fixed iron core 93. arrai'iged between magnet poles 91. and 92 of the magnet 93. These parts are. not shown in detail. as they are well known. The winding or coil has secured thereto a shaft 94, and to the shaft is secured a downwardly, depending pointer 95, both shaft 94 and pointer 95 being insulated from the winding or coil. The pointer ias its movement limited by an adjustable stop 96 at one side, and by adjustable stop contacts 97 and 98 at the other side. "he pointer is secured to a spring 99 which has its tension controlled by a thumb screw 100 movable in or supported by a stationary part 101. which may be a suitable part of the frame of the phonograph or an extension thereof. The contact point 97 has secured thereto a conductor 103, which has connected therewith in series resistance 104- and which conductorlOfi is connected with. the

conductor 85, which, as stated, is connected with the brush 84. The contact point 98 has secured thereto a conductor 105 which is secured to the conductor 89 which, as before stated, is connected in series with the resistance 90 and which conductor, as stated, conmeets with the brush 83. The conductor 107 connects the stationary frame 86 with the conductor 89 at a position between the brush 83 and the resistance 90. The frame 86 is in electrical contact with the pointer 95.

In Fig. 3 the conductors and electrical connections just described are shown diagrammatically, and the same reference characters are applied thereto, the relay 88 is shown in Fig. 3 as in yertical position,

while in Fig. 1 as ininclined position, but the position of the relay 88 is not material.

The operation underlying these electrical connections is as follows: Referring now to Fig. 1, when the disk or frame 25 with its coil 80 is rotated in respect to the magnetlc member 26, an electromotive force is produced. The resulting current flows through the brush 84, conductor 85, coil 88, conductor 89, and resistance 90, and brush 83. In this case, the pointer 95 contacts with the stop 96, and does so until the voltage produced exceeds a certain assumed normal. When, however, the electromotive force increases above this assumed normal, then the coil 88 will be moved, which will move the pointer 95, and this pointer 95 will make contact with the contact points '97 and 98. Then part of the current will flow from the brush 84 through the conductor 85 through the coil 88, conductor 89, not through the resistance 90, but through the conductor 105, past the contact point 98 through the pointer 95, through the stationary bar 86, through the conductor 107, then through the conductor 89 to the brush 83. That 1s, practically all the current will flow through the pointer in preference to going through the resistance 90. It has been said that part of the current goes through the conductor 85. The other part of the current flowin from the brush 84 passes through the resistance 104 and through the conductor 103, and past the contact point 97 into the pointer 95, then through the pointer 95, past the frame 86,

through the conductor 107, conductor 89, and back to the brush 83, of course, again avoiding the resistance 90. The resistance 104 is sufiiciently low so that the moment contact between the pointer 95 and the contact points 97 and 98 is ma e, a comparatively large current is produced which, flowing through the coil 80, produces in conjunction with the magnet 26 a larger drag. This reduces the speed of the coil 80, until the electromotive force and current produced is lowered. The pointer 95 then moves away from the contact points 97 and 98, and by reason of the spring 99 is moved .of the magnet 93 as to correspond to a definite induced electromotive force in the coil 80, independent of the loss of electromotive force in the coil 80 due to the larger current flowing when the circuit is completed through the resistance 104. However, when the pointer 95 closes with the contacts 97 and 98, then there is a drop in voltage in the windings of the coil 80, and this reduces the current flowing in the movable coil 88. In order to prevent this, the resistance 90 is practically short circuited, thus allowing the same current to flow through the coil 88 as before. The resistance 90 must be adjusted beforehand to permit this to be carried out, so that there is always the same current in the coil 88, for a given induced electromotive force, so that no matter whether the current flows through the resistance 104 or not, the same current must flow through the movable coil 88. The spring 99 is regulated by the thumb-screw 100, and it affords a means for compensating for any variation in the magnetism of the magnet 26 or any ,means of variation in the electromotive force produced. Thus the stronger the spring 99, the greater the induced electromotive force necessary to move the coil 88 and the pointer 95.

With a given tension in the spring 99, the

voltage or electromotive force induced in the coil 80 will cause the relay coil 88 to be in a certain angular position, as for instance, that indicated in Fig. 1. Though the magnet 26 may vary in its position relatively to the support 25 or coil 80, the relay coil 88 will always take the same position fora given induced electromotive force. If this electromotive force increases, then the pointer 95 would make contact with the points 97 and 98. In that case, the larger current will flow through the resistance 104, and operate in the manner described. Now the reaction between the current flowing in the coil 80 and the magnet26 will, as stated, cause a of the coil 80 and consequently the electromotive force produced, and thus the coil 88 will move back to its initial position, until the pointer 95 breaks contact with the contact points 97 and 98.

By the electric connections described, the use of friction to control the speed of the record disk, which in some cases is regarded as undesirable, as friction varies from time to time and is affected by dust or other conditions, may be dispensed with. By the means proposed, it is possible and feasible to replace the drag produced by friction, by a drag produced by utilizing the reaction between the current flowing in the winding of the disk armature 80, and the control magnet 26. The present means utilize an auxiliary circuit so as to cause a very much greater current than the normal to flow in the coil 80 for an instant, thus increasing greatly thecounter torque of the armature and thus coacting with the magnet 26 to bring about a retardation of the speed. The relay operates by constantly opening and closing the auxiliary circuit, the frequency with which it does this being dependent upon the state of winding of the spring motor 11, and upon the speed of rotation of the record disk. In other words, the relay closes the auxiliary circuit as soon as the linear velocity or induced voltage exceeds a certain per cent. increase above the normal amount, and keeps the auxiliary circuit closed'until the linear velocity or induced voltage is reduced a certain per cent. below the normal amount. In this last case, the relay again opens the auxiliary circuit, and then the operation is repeated. By the means thus described, the coil 80 not only is a means of measuring the linear velocity, but also furnishes the energy for acting as a brake for keeping the speed at a predetermined amount. One advantage of this system consists in the fact that only a very small amount of energy is consumed by the relay, and only at intervals is a large amount consumed, and this is supplied by the energy of the spring stored up as energy of rotation of the rotating parts. A further advantage is the high degree of accuracy under which the parts cooperate.

The limits of electromotive force or speed above or below the normal electromotive force or speed will depend upon the sensitiveness of the relay. If the speed is too low, pointer 95 will be drawn against stop 96, and there will be no current flowing through resistance 104. Any excess unbalanced torque of the spring will then accel erate the speed, the energy for this being supplied by the spring.

Assuming the speed of the record as one, with the stylus located at the periphery of the record, then with the stylus at a point on the record one-fifth of the radius from the center, the speed of the record will be five. In these two cases, the excess unbalanced torque of the spring will do work at the rate of one to five. By excess unbalanced torque, is meant that torque beyond that necessary to operate the parts satisfactorily. The amount of energy required in these two cases for a given per cent. increase or decrease from normal speed in the two cases, will be in proportion to the square of the two speeds, or as one to twenty-five. Therefore, the time to increase the speed from a given per cent. below normal to a given per cent. above normal speed for the two cases will be given by the ratio of the energy required to the rate of work done in each case, or, for the two cases considered, the times will be as one is to five. Therefore, the time to accelerate the speed a given per cent. with the stylus at the periphery of the record and with the stylus one-fifth of the distance from the center. will be as one to five, or in other words, as far as the acceleration of the speed is concerned, the pointer will open and close the auxiliary circuit five times as fast when the stylus is at the periphery as with the stylus one-fifth of the distance from the center.

In the case of the retardation, when pointer 95 makes contact with points 97 and 98, the rate of work done in driving the cur rent through the resistance 104, will be the same for the two cases considered above. Therefore, disregarding the effect of the excess unbalanced torque of the spring acting against the retardation produced by the current flowing in resistance 10%, which will be small, the time to retard the speed a given per cent. with the stylus at the periphery of the record and with the stylus onefifth of the distance from the center, will be as one to twenty-five. However, as the re tardation will be rapid as compared to the acceleration, the rate at which the pointer opens and closes the auxiliary circuit will be only slightly greater than five times as fast with the stylus at the periphery as with the stylus at one-fifth of the distance from the center.

The relay would operate, therefore, as follows: lVith the spring 11 wound up, and the magnet at the periphery of the coil 80. and the record revolving at say, fifteen revolutions per minute, the pointer opens and closes the auxiliary circuit comparatively quickly. As the stylus moves inward, the action of the pointer would gradually be retarded until at a speed of the record of seventyfive revolutions per minute the relay closes the circuit only one-fifth as often as at the beginning, assuming the spring fully wound. If the spring is just sutiicicntly wound to operate the mechanism satisfactorily, the pointer need not theoretically close the auxiliary circuit at all, whether the stylus is at the periphery or at the center.

Assuming the record disk 19 to rotate, and the stylus 37 to be in position, with the spring 11 wound up to operate the train of mechanism coacting therewith, the device shown in Fig. 1 may be used in various diflerent ways. Ii it is desired to use the same as a constant speed machine, then and in that case the locking member 31 is swung over to the holder 34: and the tone-arm 30 is free to move. At the same time the clutch members 72 and 73 may take the position as shown in Fig. 1, namely, in disengaged position, and the record line will drive the stylus. Similarly, in Fig. 2, when the locking member 81 is swung over the stationary holder and the clutch is in disengaged position, as shown in Fig. 2, the device causes the record disk to rotate at constant speed, and the stylus follows the record groove. If, however, it is desired to have the tone-arm 30 positively move the stylus over the record disk 19, the clutch members 72 and 73 are brought into engaging position. In this event, the machine may be used either as a constant speed machine by having the looking member in engagement with the member 34:, or the machine may be used as a constant linear velocity machine by swinging the locking member 31 into the position shown in Fig. 1.

When the pointer 95 is moved into contact with the contacts 97 and 98, the operation hereinabove described takes place, until the induced electromotive force again reaches a little below normal so as to permit the pointer to be swung back to its initial position against the stop 96 by virtue of the action of the spring'99. The swinging of the pointer from its position against the stop 96 to its position against the contacts 97 and 98 takes place when the induced electromotive force is increased above the nor mal, and its return swing takes place when the induced electromotive force is again a little below the normal. Thus any tendency to increase the speed of the coil 80 resulting from the unbalanced excess torque otthe spring 11, such as to change the electromotive force induced by the cooperation of the coil 80 with the magnet 26, will bring the speed back to a speed a little below the normal. Any increase of speed of the coil 80 will cause the drag to take place and this brings the speed back again to a little below normal. This variation or fluctuation of the speed a little above normal and a little below normal, within narrow limits, brings about a general average, which is, of course, the normal speed. This variation above or below the normal, within these very narrow limits, is considerably less than similar variations above or below the normal obtained in the use of the ordinary ball governor, as applied to the ordinary phonograph.

The result of this control, and the cooperation of the relay with its electrical connections described, brings about a substantially constant linear velocity of the record line with respect to the stylus.

If it is desired to use the phonograph as a constant speed machine, which may be done as before stated, the lever 31 is thrown into the stationary member 3i, and permits thereby the tone-arm 30 with its stylus to move over the record disk independently of the magnet 26, which now becomes locked in position by reason of the lever 31 engaging the locking support 3 1. In this case the relay with its electrical connections acts in the same way as hereinbefore described. In this case, with the record disk rotating at a constant speed, any unbalanced excess torque will tend to increase the speed of the record disk. This tendency to increase the speed would cause larger induced electromotive force to be created, by reason. of the cooperation of the coil 80 with the magnet 26, which magnet 26 is now stationary. But this induced electromotive force will move the coil 88 and hence move the pointer 95 into contact position with the parts 97 and 98, and will bring about an action as described hereinbetore, so that with any tendency to change the speed of the support 25 with its coil 80, for any position of the stylus on the record disk, the induced electromotive force will cause a cooperation of the windings 8S, and the electrical connections, until the speed is again brought down somewhat below the normal, and the fluctuations above and below the normal within very narrow limits will again take place, so that the average or normal speed produced Will be maintained for all positions of the stylus.

In Fig. 4 is shown a portion of a'phonograph operated by means of electric power, and utilizing the armature and magnet as a motor for use on constant linear velocity records. The frame of the phonograph supports the record disk table 111 on which the record disk 112 is suitably placed, and

which record disk is engaged by the stylus 113 of the sound box 114 on the tone arm 115 whichcomniunicates with the horn 116. The tone arm has secured thereto the vertical rod 118 by means of the key pin 119. This vertical rod 118 passes through the horn 116 at 120 and has its lower end secured to a bracket 121 by means of screws 122. The bracket 121 supports and has secured thereto permanent magnet 123, which moves with the tone arm 115. The rotatable table 111 has secured thereto the shaft 125, to which in turn is secured the v gear wheel 126 meshing with a pinion 127 through which the shaft 128 passes, and on which shaft 128 the commutator 129 is secured. The rotatable plate or disk or frame 130, which passes between the jaws of the permanent magnet 123 is also secured to the shaft 128. Suitable wires 131 connect the commutator 129 with the armature 132, the armature 132 having its wires wound into suitable coils in a manner similar to the windings shown in Fig. 5, and more partic ularly shown in my previous patent application Serial No. 855,618, filed August 7th, 1911, patented January 16th, 1917, No. 1,212,693. The commutator 129 is electrically connected with the brushes 136 and 137, the brush 136 being connected with the conductor 138 which in turn contacts with a variable resistance 139 which is in series with the terminal 140. The other terminal 1&1 is connected with the electrical conductor 112 which is connected with the brush 137.

The impressed electromotive force enters at the terminals 1&0 and 1 11 and the commutator 129 has its brushes 136, and 137, together with the coil 132 and permanent magnet 123, act as a motor, and thereby the shaft 128 is rotated, so that the coacting train of mechanism rotates the record disk 112. As the stylus 113 moves inwardly or outwardly, the shaft 118 is moved corre spondingly and the permanent magnet 123 moves therewith. This permanent magnet 123 may be replaced by an electromagnet connected in series or shunt with the armature.

In certain cases the frame 130 is provided with cut-out portions of such a shape that the current flowing into the armature is a constant for a constant electroinotive force impressed on the motor terminals. The varying elements that need to be balanced in order to maintain the current constant, are the windings and friction of the moving parts for various speeds, the friction of the brushes on the commutator for various speeds and the possible variations in the electrical loss in the brushes, due to the various speeds. Theoretically, the stylus, for a constant linear velocity phonograph, will take a constant power to drag it over the record disk, as the product of torquearm and speed is a constant. Hence all the above losses can be balanced by suitably cutting out portions of the disk, so that for each position of the stylus on the record disk, with a constant linear velocity, there will be a certain constant friction and eddy current loss, thus requiring a constant power to overcome the losses in the phonograph. The necessary torque will vary inversely as the speed, but the product of the two, or the power, is constant. Therefore, for a given constant impressed voltage at the motor terminals, there will be a constant drop in voltage, due to a constant current flowing and a constant armature resistance, thus leaving a constant counter electromotive force or induced voltage, and therefore a constant relative linear velocity of record line and stylus. If stable conditions of operation have been obtained at one position of the stylus on the record, moving the stylus inward to a new position will momentarily reduce the counter electromotive force, thus allowing a greater current to flow, which will cause the disk armature to speed up, until the former counter electromotive force is reached, when the current will be the same as before, and hence the linear velocity will be as before. And on the other hand, moving the stylus outward will increase the counter electromotive force, and reduce the current flowing, thus causing the speed to be reduced.

By arranging the resistance in series with the motor adjustable, the linear velocity of the record line and stylus can be adjusted to the proper amount.

This method of operation may, of course, be styled empirical, in that the cut-out portions of the disk must probably be adjusted or changed for each machine.

I have described several embodiments of my invention, but it is clear that changes may be made therein without departing from the spirit thereof as defined in the appended claims.

I claim 1. In a phonograph, the combination of a record medium, a medium coacting therewith and movable thereon, means for moving the record medium, means operated by said last-named means for positively moving the coacting medium, members magnetically coacting with each; other, means for changing the action of one of said magneticallv coactingmembers upon the other, upon the change-of position of the said coacting medium on the record iiedium, and means capable of changing the relative linear velocity of the record medium and coacting medium at their coacting point on the change of action of one of the mag netically coacting members with the other.

2. In a phonograph, the combination of a record medium. a medium coacting therewith and movable thereon, means for moving the record medium, means operated by said last-named means for positively mov ing the coacting medium, members magnetically coacting with each other, means for changing the action of one of said magnetically coacting members upon the other, upon the change of position of the said coacting medium on the record medium, means capable of changing the relative linear velocity of the record medium and said coacting; medium at their coacting point, on the change of action of one of the 1 magnetically coacting members with the other, means on one of said magnetically coacting members for inducing therein electric energy, and means operated by said electric energy for maintaining the relative linear velocity of the record medium and coacting medium at their coacting point, substantially constant.

3. In a phonograph, the combination of a record medium, a medium coacting thrrewith and movable thereon, means for moving the record medium, means operated by said last-named means for positively moving the coacting medium, members magnetically coacting with each other, means for changing the action of one of said magnetically coacting members upon the other upon the change of position of the said coacting medium on the record medium, means capable of changing the relative V linear velocity of the record medium and said coacting medium at their coacting point, on the change of action of one of the magnetically coacting members with the other, means on one of said magnetically coacting members for inducing therein electromotive force, and means operated by the resulting electric energy for maintaining the induced electromotive force approximately constant.

4. In a phonograph, the combination of a record medium, a medium coacting therewith and movable thereon, members magnetically coacting with each other, means for changing the action of one of said magnetically coacting members upon the other, upon the change of position of the said coacting medium on the record medium, means capable of changing the linear velocity of the record medium relatively to the said coacting medium, on the change of ac- .tion of one of the magnetically coacting -members with the other, means on one of 5. In a phonograph, the combination of a. record medium, a medium coacting therewith, means for moving the record medium, members magnetically coacting with each other, one of said membersbeing moved by the means for moving the record medium, means on one of said members for inducing therein an electromotive force, a relay in circuit with the inducing means, and electric energy absorption means operated by the relay.

6. In a phonograph, the combination of a record medium, a medium coacting therewith, members magnetically coacting with each other, electric energy conducting means on one of said members, means for supplying electrical energy to said last-named means, means connecting one of said members with the record medium for moving the record. medium on the movement of one of said members, means operated by said lastnamed means for positively moving the coacting medium in respect to the record medium, and means connecting the other member with the coacting medium for moving the said member on the movement of the coacting medium.

7 In a phonograph, having a record medium, and a medium coacting therewith, and members magnetically coacting with each other and comprising two elements of an electric motor, one of said members being movable with respect to the other, so

that a constant induced electromotive force in one of the said members results in a constant linear velocity of the coacting medium with respect to the record medium at their coacting point.

8. In a phonograph having a record medium and a medium coacting therewith, and members magnetically coacting with each other and comprising two elements of an electric motor, one of said members driving one of said mediums and the other member movable with respect to the first said member, so that the linear velocity of the two members with respect to each other, at their coacting point, bears a constant relationship to the linear velocity of the record medium and the coacting medium relatively to each other at their coacting point.

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

Jos. BISBANO, JOHN SCHWARZ.

Images