US1599861A - Tone arm and yoke for phonographs - Google Patents

Description

Sept. 14 1926.

c. A. YATES Tom: ARMAND YOKE FOR PHONOGRAPHS C'b/P/Ic'eA. Yates Aiyo Filed May '7, 1923 2 Sheets-Sheet 1 'lIllllllllllllfl Sept. 14 1926. 1,599,861

C. A. YATES TONE ARM AND YOKE FOR PHONOGRAPHS Filed May 7. 1923 2 Sheets-Sheet 2 llllllllliillllll-llllm, l A -'I F 4 Z] Clarence/1. Kites H jf wiwmo'zlw Patented Sept. l4 ,1926.-

UNITED STATES PATENT OFFICE.

CLARENCE- A. YATES, OF LOB ANGELES, CALIFORNIA, ASSIGNOB ONE-HALF TO FRANK E. COTTEB, 01 LOS ANGELES, CALIFORNIA.

TONE ARM AND YOKE FOB PHONOGRAPHS.

Application filed Kay 7,

My invention relates to sound reproducing apparatus of that type embodied 1n my copending application filed October 1, 1921, serially numbered 504,683, in which sound waves are regenerated by a conical shaped fibrous tymganum without the employment of an ampli cation device. I

It is a purpose of my present invention to provide a sound reproducing apparatus of the above described character having a vibration conducting mechanism includin a tubular member provided with a. reedike extremity which is associated with a rigidly sustained stylus holder in such manner that l the vibrations set up by the stylustraversinga sound record efiect molecular vibrations of thetubular member which, although being of increased intensity, are transmitted to the t panum without distortion so as to pro- 2 SOHIld waves of unusually large volume and great carrying power.

It is also a purpose of my invention to provide a sound reproducing apparatus in which the sound wave conductin mechanism embodies a bridge-like mem er rigidly mounted for molecular'vibration, with the reed-like extremity of the tubular member associated therewith so as to heel respond to the molecular vibrations thereo whereby, the sound (producing undulations or a record are cause to be converted into molecular vibrations and accurately transmitted to the tympanum.

A further purpose of my invention isa as provision of a mounting for the tympanum and vibration conducting mechanism which not only allows of the necessary universal adjustment of these elements in permittin the stylus to accurately follow the soun groove of a record, but utilizes the weight of the tympanum and conducting mechanlsm to counterbalance each other so that the pressure imparted to the stylus will be so slight as to prevent wear of the vibration producl ing undulations of arecord, but suflicient to cause the accurate reproduction of the vibrations by the stylus.

Another purpose of my invention is a provision of a sty us holder which sustains the co stylus at such an angle with respect to the plane of a disc record as to prevent the point of the stylus from engaging the bottom of the sound groove thereby eliminating the noises generated incident to the contact of the stylus point with the bottom of the sound 1928. Serial No. 687,057.

roove. Further, the stylus holder allows of t e projection of the stylus from the holder various distances whereby the intensity or volume of the sound waves reproduced can be regulated at will.

Althou h I have shown and will describe only one orm of sound reproducing. a paratus embodying m invention, it isto understood that various changes and modifications may be made herein without departing from the spirit of the invention and the spirit and scope of the appended claims.

In the accompanying drawings Figure 1 is a view showing in side elevation one form of sound reproducing ap aratus embodying my invention in applie position within a cabinet.

Fig. 2 is an enlarged fragmentary view showing in side elevation the sound reproducing apparatus shown in Fig. 1.

Fig. 3 is a view showing the apparatus in vertical longitudinal section.

Fig. 4 is a fragmentary view showing in side elevation the mounting for the apparatus. I

Fig. 5 is a fragmentary sectional view showlng a portion of the mounting shown in Fig. 4.

Fig. 6 is an enlarged sectional view partly in elevation of the sound wave conducting mechanism embodied in the apparatus shown in Fig. 2. A

Fig. 7 is a fragmentary view showing in ipp plan one end of the mechanism shown in Fig. 8 is a fragmentary view showing in side elevation that portion of the mechanism shown in Fig. 7.

Fig. 9 is a transverse sectional view taken on the line 99 of Fig. 7.

Fi 10 is a transverse sectional view of a soun groove of the record shown in Fig: 1 with the stylus in applied position.

Similar reference characters refer to simiv lar partsin each of the several views.

Referring specifically to the drawings and particularl to Fig. 1, my'invention in its present em odiment is shown as housed in a cabinet K having a filigreed front side 15, and a rear side provided with an opening controlled by a door 16. Through this opening access is had to the interior of the cabinet for manipulating the apparatus and aplying and removing sound records to and ii-om the turntable. Within the cabinet K is located a housing 17 which contains the mechanism for driving a turntable 18 upon which a disc record 19 is adapted to be supported.

The sound reproducing apparatus embodying my invention comprises, in the present instance, a standard 20 arranged in front of the housing 17 and rigidly braced by an arm 21. Upon the upper end of the standard 20 is secured, as clearly shown in Fig. 3, a mounting including a base 22 provided centrally thereof with a bearing collar 23, and extendin upwardly from the collar is a substantial y L-shaped arm 24 rovided at its horizontal portion with an a justable bearing element 25. A yoke 26 of rectangular outline is provided with a depending extension 27 which is journaled in the collar 23. .The upper portion of the yoke 26 is recessed as indicated at 28 to provide a bearing for the member 25. Thus the members 25 and 27 cooperate to allow limited rotational movement of the yoke about a vertical axis. The yoke 26 carries in its vertical portions a pair of screws 29 having conical bearings formed on their inner ends for engagement with two recesses provided in a supporting arm 31. The arm 31 is of tubular form, as clearly shown in Figs. 2 and 3, and is provided with cutaway portions 32 to accommodate the yoke 26 and thus provide for the necessary movement of the arm upon the yoke in applying the sound reproducing apparatus to or removing the same from the sound record. Through the medium of the screws 29, the arm 31 is capable of swinging movement about a horizontal axis, and by virtue of the mounting of the yoke 26, it will be clear that the arm 31 is also capable of being swung about a vertical axis.

The various elements forming the universal joint shown in Fi 3 form what is technically known as a gimbal joint.

As shown in Figs. 2 and 3 the arm 31 is formed of relatively hard steel or other suitable metal and of such ponderous proportions and weight that they will be unresponsive to the rigid mechanical vibrations of the stylus. As shown, the arm 31 is connected to one end of the casing 33 and disposed at an angle with respect to the casing so that when t e apparatus is in active position it will occupy a position inclined with respect to the perpendicular, while the casing 33 will assume "a position substantially parallel to the turntable 18.

As shown in Fig. 3, the '33 contains a vibration transmitting member 34 which is of tubular form and provided with relatively thick walls so that/it will not respond to the mechanical vibrations. This transmittin member, as clearly shown in Figs. 6 and 7, is provided at one end with a reed-like extension 35, while adjacent such extension the tube is beveled as indicated at 36 so that the tube is tapered in the direction of the extension 35 for a purpose which is hereinafter described. The opposite end of the member 34 is supported concentrically within the casing by means of a felt plug 37 bored to receive the tube 34 and of a diameter to snugly fit within the end of the casing 33. The adjacent end of the tube 34 is threaded interiorly as indicated at 38 in Fig. 6, to receive a screw 39. This screw 39 supports a pair of conical shaped clamp ing plates 40 which embrace the apex of a conical shaped tympanum 41 formed of fibrous material such as paper, cardboard, or the like. The adjacent end of the tube 34 is provided with beveled edge 42 so as to conform to the contour of the inner plate 40 and thus provide a snug fit between the two. The screw 39 carries a pair of nuts 43 the inner one of which engages a washer 44 havin' a beveled edge to snugly fit the outer clamping plate 40. The outer nut serves as a lock nut for securing the inner nut against rotation.

As shown in Fi 7, the reed-like extension 35 is connecte to the bridge portion 45 of a stylus holder through the medium of anextension 46 rigidl secured to the portion 45 and having a t readed projection 47 to receive a nut 48 for securing the extension 35 to the extension 46. The bridge portion 45 is rigidly secured to a supportin bar 49 through the medium of screws 50 w ich extend loosely through suitable openings in the bar 49 and which threadedly engage the bridge portion 45 adjacent the ends thereof, as clearly shown in Fig. 6. The bar 49 is provided with terminal projections 51 which receive screws 52 for rigidly securing the bar within the casing 33, as clearly shown in Fig. 3. The screws 50 serve to hold the bridge portion 45 in engagement with hearing pins 53 seated within the bar 49, as shown in Fig. 6, which are arranged to engage the bridge portion at the opposite ends thereof.

Extending medially from the bridge portion 45is a stylus supporting arm 54 having a depending extension 55 formed with a duct 56 which is co-extensive in length with the extension so as to accommodate styli of difierent lengths or to allow the longi tudinal adjustment of a stylus so that it can bemade to project various distances from the extension. The stylus designated at 57 is retained in any adjusted position within the extension by means of a set screw 58.

In the operation of my invention the cas ing 33 serves as a handle to move the sound conducting mechanism and the tympanum upon the mounting so that one can apply the stylus to the record 19 or move the same to inactive position at one side of the turntable. It will be understood that the mounting for to follow the sound groove of the record 19. With the stylus in applied position upon the record to engage the records undulations,

the stylus holder is Subjected to molecular vibrations by virtue of the fact that the bridge member 45 is rigidly secured to the bar 49. This molecular vibratory movement of the bridge member 45 is transmitted to the reed-like extension 35 through the extension 46 thereby setting up in the conducting member 34 molecular vibrations of greatly increased intensity as compared to the vibrations occurring in the stylus holder. It will be understood that the reed-like member is extremely sensitive to vibrations because of its attenuated form, and that as a consequence the molecular vibrations of the stylus holder are intensified during transmission from the holder to the member 34. With the member 34 subjected to intensified molecular vibrations, such vibrations are directly transmitted to the tympanum as the.

' and low pitch as well as the tones of medium pitch, and in fact I obtain a reproduc tion of tones ordinarily lost in the graphophones heretofore produced.

In order to secure this superior tone reproduction, it isnecessary that the stylus holder be formed of case hardened metal such as steel, tungsten, or the like in order that there may be no excessive molecular vibrations therein when the stylus is excessively vibrated. To carry out this idea the member 34 is made of relatively hard metal, which may or may not be of the same degree of hardness as the member 34. Both the casing 33 and the arm 31 are preferably formed of metal but as these elements are not subjected to molecular vibrations, the degree of hardness of the metal of which they are formed is immaterial.

As previously mentioned, the stylus is supported through the medium of the stylus h holder so as to occupy an lnclined position with relation to the record to prevent its point from actually contacting with the respond to the undulations of the record 'while it is at the same time held out of engagement with the bottom of the sound groove thereby eliminating the noise in-- cident to such engagement.

The stylus 57 is of a type having a blunt point forming a close fit between the opposite sides of the groove and therebysupporting the stylus so that its point does not engage the bottom face of the groove.

From a consideration of Fig. 2, it will be seen that the fulcrum point 29 for the arm 31 is disposed at one side of the connection between the casing 33 and the tympanum 41 thus causing the weight of the tympanum to partly counterbalance the weight of the casing and arm so as to render the pressure exerted by the casing and arm upon the stylus 57 relatively slight. As a consequence, the pressure exerted by the stylus upon the record is correspondingly slight so that the undulations of the record are not subjected to any undue wear. I consider this counterbalancing feature of the Weights -of the casing and tympanum a. very important part of my invention because I have found in practice that after repeated use of 'a single record no appreciable wear of the record is apparent, and as a matter of fact, the quality of the sound reproduction appears to improve with use.

What I claim is 1. A sound reproducing apparatus coinprising in combination a gimbal joint, an arm connected thereto, a tubular casing secured to the arm near one end of the easlng, a bridge secured to the opposite end of the casing, a stylus holder spaced from but connected to the bridge, a vibration absorbmg plug at the opposite end ofthe casing from the bridge, a vibration transmitting hollow bar secured to the stylus holder, and a tympanum mounted on the opposite end 0f the bar.

2. A sound reproducing apparatus comprising a casing, a'stylus holder including a bridge portion sustained within the casing,

. ing, a reed-like extension formed in one end of the tube and connected to said lateral extension, and a tympanum of conical form supported at'its apex upon the other end of said tube.

3. In a sound reproducing apparatus, a tubular supporting casing, a bar secured at one end of the casing, a stylus holder ineluding a bridge, relatively sharp bearing members interposed between the bridge and the bar, fastening members engaging the bar and bridge for holding the bridge in contact with the said bearing members, a stylus secured to the holder, and a sound transmitting rod also secu ed to the holder and passing through the casing.

4. In a sound reproducing apparatus, a stylus holder, means for sup orting the stylus holder, -a sound transmittin rod having a central bore therethrough an cut away at one end completely across the bore and leaving a thin reed-like portion, means for connecting the reed portion to the stylus holder, and a tympanum supported by the other end of the rod.

5. A sound reproducing apparatus comprising in combination a tubular casing, 21 gimbal joint, a support therefor connected to said gimbal joint, abar having terminal projections with screws securing the projections rigidly to one end of the casing, a stylus holder having-a bridge, sharp bearing threaded members holding the members spacing the bar and brid e, screw er and bridge pressed toward each other, a stylus connected to the bridge, a rod having a central bore therethrough and cut away at one end completely across the bore leaving a reed-like portion at one end, a pin securing the reed-like portion to the stylus holder, said rod extending through the casing and supported at the opposite end from the stylus holder, and a tympanum secured to the end of the rod by a screw threaded into the bore of the rod.

In testimony-whereof I have signed my name to this specification.

CLARENCE A. YATES.

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