US1325673A - Speed-kegttlatok - Google Patents

Description

E. M. HILL.

SPEED REGULATOR FOR GRAPHQPHONES.

APPLICATION FILED MAY 15. 1918.

Patented Dec. 23,1919.

2 SHEETSSHEET 1.

E. M. HILL.

' SPEED REGULATOR FOR GBAPHOPHONESI v AFN-NATION FILED MAYIE), 918. Ififififi'? Patented Dec. 23,1919.

2 SHEETSSHEET 2,

16 Ill EARL. lVL HILL, or ionr'roiv, onto.

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Application filed May 15, 1918. Serial No. 234,666.

To all whom it may concern:

Be it known that I, EARL M. HILL, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Speed-Regulators for Graphophones; and I do hereby declare the following to be a full, clear, and eXact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of the invention is to provide graduated speed regulating means for use in connection with phonographs, graphophones and similar instruments both in the original production or formation of the records and in the reproduction thereof so as to utilize to the utmost and economize the space or surface of the record with a view to increasing the capacity of the same as compared with those now in use and ordinarily employed. In order that the ad vantages of the invention may be fully appreciated it should be noticed that in the present practice, both in the formation of the record and in the reproductionthereof, the record disk is operated at a uniform speed of rotation, that is to say a uniform angular movement, and therefore at the outer portion of the surface of the record, or near the periphery thereof, the linear movement of the tone groove or record groove is very much more rapid with reference to the needle than near-the center or end of the record. Consequently in order that the tone groove may travel with reference to the needle at the desired speed as the latter approaches the center of the record, it is necessary to drive the record at such a rate as to use the outer portion of the surface very much more rapidly than is required and much more rapidly than the inner portion thereof. It is the depot of this invention to provide for securing a unlform speed of movement of the tone groove with reference to the stylus or needle, and to this end to adopt and producea graduated speed or rotation of therccord, said speedbeing relatively slow when the stylus or needle is in engagement with the entrance to the tone groove and increasing gradually" and uniformly as the stylus or needle approaches the center, so that the lineal speed of movement of the groove may be uniform throughout. In this way a record of from seventyfive to one hundred per cent. greater length can be placed upon the same superficial area thereof must be used both in originally producing the record and in reproducing the same. a i

Further objects and advantages will appear hereinafter in the course of the following description of the preferred embodiment of the invention, but it will be understood that changes therein, within the scope of theappended claims may be resorted to without departing from the essential principles of the spirit of the invention.

In the drawings:

Figures 1 and Qare diagrammatic views indicating graphically the relative angular velocities of the record when the stylus or needle is in engagement with different portions of the tonal groove respectively near the periphery and near the center of the record. i

Fig. 3 is a sectional view showing a means whereby the graduated speed of revolution ofthe record carrying table may be secured.

Fig. 4-. is a detail sectional view on the plane indicatedby the line 4:-fl of Fig. 3.

Fig. 5 is a sectional view on the plane indicated by the line 55 of Fig. 4.

Fig. 6 is a sectional view on the plane indicated by the line 66 of Fig. 3.

In order that a uniform lineal speed of movement of the tonal groove with refer-A ence to the stylus or needle may be secured it is necessary that starting with a given rate of rotation of the record carrier 10, it will be necessary to increase the angular velocity of the record as the stylus,which is indicated at 11, approaches the center of the record, the relation of angular velocity of disk, it being understood of course that the r same method and means or the equivalent to speed of travelof the tonal groove being indicated comparatively in Figs. 1 and 2 wherein, during a given length of time a which may be selected as a unit, the por tion of the tonal groove terminally indicated by A and B will traverse the stylus, or will pass within. operative relation therewith. This length of tonal groove near the periphery of the record, as shown in Fig, 1, .will necessitatea comparatively slow angular movement of the record as shown by the radial lines a, and 6, whereas a similar length of tonal groove near the center of therecord, as shown at A and B, will be brought into operative relation with the stylus only by a much morerapid angular velocity of the disk, as shown by the radial lines a and Z) in Fig. 2. The regulation of the angular velocity may be accurately secured from and controlled by the tone arm or sound box carrying arm 12 of the ordinary graphophone or phonograph, as shown in Fig. 3, by providing a graduated brake mechanism, the stress of which is dependent upon the position of the tone arm or is dependent upon. whether the stylus is operating near theperiphery or near the center of the record. In the construction illustrated, the brake disk 13, which may be of the ordinary form having the adjustable contact 1% and regulating screw 15, may be utilized by employing an auxiliary brake shoe 16 carried, for example, by a lever 17 which is pivoted at 18 and is provided at its free end with a cam 19 in the path of the extremity of a shifting lever 20. A spring or similar yielding means 21 serves to hold the auxiliary brake shoev in contact with the brake disk 13 with which may be connected the ordinary governor 22 and related parts while the shifting lever may in turn be provided with a spring or other yielding actuating means 23'tensioned to hold the extremity of the shifting arm out of engagement with the cam 19 or move the said extremity in a direction to release the cam and thus permit the tensioning spring 21 to force the auxiliary brake shoe into contact with the disk. Arranged upon the tone arm 12 of the instrument is a. cam 2% operating in relation to the other arm of said shifting lever and tending as the tone arm moves inward 0r carries the stylus inward, to move the shifting lever and cause its opposite terminal' to traverse the cam 19 in opposition to the tension of the spring 23 and thus move the lever 17 in opposition' to the spring 21 and thereby diminish the frictional pressure of the auxiliary brake shoe upon the brake disk 13.

In other words, with the auxiliary brake shoe in contact with the brake disk 13 at a prescribed stress, sufficient to cause the operating mechanism of the disk carrier to rotate at a slow speed when the stylus is in engagement with the tonal groove of the record near the periphery of the latter, the gradualinward movement ofthe stylus accompanied by the swinging movement of the tone arm 12 will cause a corresponding gradual movement of the shifting lever and hence will cause the latter to gradually traverse the surface of the cam 19 and move the auxiliary brake shoe to gradually relieve the frictional pressure upon the brake disk and permit a gradually increasing rapidity of movement of the carrier actuating means. Moreover, it will be understood that this graduation or gradual increase in the velocity of the actuating means maybe accomplished regardless of the initial speed of movement which may be controlled as in the ordinary way by the brake mechanism including the brake shoe 1% and adjusting screw 15, the effect of which remains constant throughout and the purpose of which is to accurately determine the fundamental or initial speed of rotation of the record so that the proper pitch of tone and an effective reproduction of the record may be secured.

In order that the adjustment of the cam 19 with reference to the shifting lever 20 may be effected, so that the desired initial speed of rotation of the brake disk may be possible, the fulcrum 18 of the cam lever 17 is mounted in a sliding bearing block 25 suitably arranged in the frame of the machine and controlled by a regulating screw 26.

The illustrated means for securing the above described results are obviously susceptible of modification in various ways, particularly in adapting the invention to difierent types and makes of machines, but essentially the same consists in speed controlling or regulating means with reference to the angular velocity of the record carrier variable proportionately to the distance radially between the stylus and the axis of movement of the record to secure a uniform linear progress of the tonal groove with relation to the stylus.

Having described the invention what is claimed is:

1. The combination with. a phonograph having a record support, a stylus supporting arm and a brake mechanism including a disk and brake shoe, an arm pivotally secured to the brake shoe, resilient means sup porting the inner end of the arm, a cam formed on the free end of the arm, and a shifting member actuated by the stylus arm for progressive movement relative to the cam to gradually reduce the frictional contact of said brake shoe with the disk of the brake mechanism.

2. The combination in a phonograph having a record support, a stylus supporting arm and a brake mechanism including a disk and brake shoe, means pivotally securing the brake shoe in position, a rearwardly extending arm pivotally secured to the lower end of the brake shoe. a cam formed on the free end of the arm, resilient means supporting the inner end of the arm, and a cam carried by the stylus arm for progressive movement relative to the first mentioned cam and arranged in the path of the same to gradually reduce frictional contact of said brake shoe with the disk brake mechanism,

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

EARL M. HILL.

VVitnesses-z THOMAS S. GARRE'FI, PHILIP E. DOFFERBERTIL

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