US1432139A - Sound reproducer - Google Patents

Description

IVI. J. TRUIVIBLE.

SOUND REPRODUCER.

APPLICATION FILI-:D APR, 25. I92I.

Patnted; Oct. i7, 1922..

revisarse oei., i7, iaaa UNHTE @Filial-@ido 'MILN 5'. TRUMBLE, OFT ALHAHIBEJA, CALIFORNCA.

sonno anraonocna.

A.hmplileaftion nled'flprll ay 19531.

To all whom it may concern:

Be it known that l,

MILON J TRUMeLn,

a citizen of the United States., residing at Alhambra, county of Los Angeles and State 5 of California, have invented a new and use- Jful improvement in Sound Reproducers, of which the following is a specification.

of soundand is invention relates particularly applicable to to the reproduction the reproduction of sound from phonograph records.

Referring to the drawing which is for illustrative purposes only,

Fig. 1 is a side elevation of my invention when applied to a sound record is groove.

Fig. hy the line 2-2 of disc record in which the formed on the side'oi the 2 is a section on a plane represented Fig. 1, and,

, Fig. 3 is a section on a plane represented by the line 3-3 ln the form of et Fig. 1.

the invention shown., a

supporting structure 11 isprovided in which a sound ch amber 12 is formed., the front of this sound chamber being closed by a main diaphragm 13 and the bach of this sound chamber having an opening lllthrough which the sound p llflounted on pivots E cn i hy means ci screws 21 is a stylus holder 22 asses into a tone arm 15. 'the structure 11 which has a socket in which the stylus or needle 23 may loe placed, this needle being clamped therein by means of a screw 24C. rlhe stylus holder 22 extends up and is provided with a round end 25 having a facing of rubber or similar material which presses against the center oi the diaphragm 13. 'Eiztending through an opening in the stylus holder 22 is one end of a cross lever 31, this cross lever being in ounted on pivots 32 which' are parallel to the stylus holder 22. 7llhe other end 38 of screw 34., the roun against a drum diaphragm the iront ot an auxiliary chamber 36, such chamber having a hack thereof.

it will 'be noted that the is substantially at holder 2Q which is movements parallel to the diaphragm 13 and the stylus holder 22. By

at right angles to the cross lever 31 carries a ded end or which presses 35 which closes relief opening 37 in the cross vvlever 31 right angles tothe stylus thus restrained from any Serial No. tslwt restraining the stylus holder in this manner, l eliminate a great deal oi? the scratchy sound produced hy ordinary reproducers. IThe screw 34 is set up until the drum diaphragm 35 exerts considerable pressure between the end 25 of the stylus holder 22 and the main diaphragm 18. l have found that the dia'- phragm 13 may be conveniently made oit mica and that the drum diaphragm 35 may be conveniently made of very thin metal. l have also found that it is preferable to malte the drum diaphragm 35 and the main diaphragm 13 of different diameters so that they wil have different periods of vibration. The reproduced sound is improved by placing an anvil in the sound chamber 12' and l pre` ier to use a conical shaped anvil i6 suspended in such chamber at three points by means oit screws 4:7. The anvil i6 is provided with an opening i8 extending therethrough at right angles to the diaphragm 13, the ace of the anvil having a series of circular grooves and the sides of the anvil'being spaced apart and substantially conforming to the walls of the chamberil.

ll have ,further found that by making a reproducer substantially as shown, that y. l produce a very clear reproduction o the record which reproduction is not marredhy scratching noises which are often noticeable when an ordinary'reproducer is used.

l claim as my invention:

1. a phonograph reproducer, the comhination of: a 'supporting structure; a mainv diaphragm closing the h'ont oi a sound cham loer formed in said structure; means for attaching a tone arin to said structure; a styhis holder flexibly mounted on said structure and having its upper end in contact with said diaphragm; means for securing needle in the other end oit said stylus holder; a cross lever engaging said stylus holder; drum diaphragm against which one end of said cross lever rests; .and pivots parallel to said stylus holder v upon which said cross lever isA supported. l

2. ln a phonograph reproducer, the coinbinationvof: a supporting structure; a main diaphragm closing the front ci a sound chamher formed in said structure; means tor attachin a tone arm to said structure; .a stylus ho der dexibly mounted on said strucmamas@ upon which `xsmicfcross lever f, I have hereunto set, 10 goles, California, this 21.

dmphm against which one ond of' said cross lover rests; amd piyots parallel to said.

oN mmm.,

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