US1417718A - Diaphragm - Google Patents

Description

A. F. R. COTTON.

` DIAPHRAGM.

APPLICATION FILED FES. 8,1921

1,417,718, Patented May 30,1922.-

-F1g1. ngz. Flg. Figa.

ARTHUR. FREDERICK RIcHMoND corro-N, or LONDON, ENGLAND.

To all. 'whom-,it concern:

Be it known `that I, ARTHUR FREDERICK 'RICHMOND Co'i'roN, a British-subject, residing at la Chesterfield' Street, Mayfair, L on-l don,Fingland, have invented certain new and useful Improvements in Diaphragms, of

which the following is a specification;

vThis invention relates to vibratory diapliragmsv for' telephone receivers, for the sound boxes4 of gramophonesand the like,

DIAPHBAGM.

Specication of Letters Patent. Patented luay 30,' 1922.

s, i921. serial No. 443,331.

tained the best results by employing a woven linen fabric of the kind known as tracing Cloth. A y

The fabric -is Cut into discs of suitable size, and is applied to a celluloid sheet or disc b preferably thicker (Figure 2), which .is treated with aeroplane dope, acetoneV or like solvent; the/,two juxtaposed materialsv (see Figure 3) are preferably subjected to slight pressure,.whereby the softened Celluandfor other similar purposes, and consist/s. loid is caused to penetrate the textile mateof an improved diaphragm suitable both for the preparation of sound records and for the reproduction ofV sound `by .records or other means. The main object is. to provide a diaphragm with no .musical note or fre- -quency of its own and thereby to eliminate resonance effects due to the actual material of the diaphragm.

According to the 'present invention, Vthe discforming .the diaphragm is composed of one or more layers of woven or other fabric Aof textile material which is or are stiifened lposed discs ready for pressure. f

Figure 5 illustrates a frame\liolding the by` impregnation with Celluloid by means of asuitable solvent of the latter.

A4The invention ,is hereafter more fully described withl reference tothe accompanying drawings, inwhich f .t

Figures 1 and 2 represent ,suitable discs of linen `and celluloid respectively for the construction .of thel diaphragm.

Figures 3 and 4 show sections of the j uxtatextile material before application of the Celluloid disc.

Figure 6 representsl in section the coml pleted diaphragm ready for mounting.v

Figure 7 is an elevationl of a Completed diaphragm suitable for a telephone receiver.

Figure 8 is a section of the same.

- Figure) is an'elevation of a diaphragm for the soundbox of a gramophone.

Figure 10 is a part sectional elevation of the diaphragm fitted -inthe soundbox.

The improved diaphragm A comprises a foundation. Consisting of artextile fabric,

g `which may be of cotton, muslin, linen or silk, and is'stilfened by impregnation with Celluloid. The fabric may be woven as v .shown by the disc a iniFigure 1`, or may Consist of superposed layers al a2 of parallel threads, as shown in Figure 5, where the two layers merely cross one another. I have ob- !UNITEDVSTATES Ai'nrrsla'l A ofi-Tricia.

rial. The solvent lis then removed, its departure being accelerated by artificial drying if desired.

Alternatively4 the linen or like material may be stretched in` a suitable frame c as shown in Figure 5, in which it is gripped around lthe periphery by means of clamping nuts cllpressing upon a cover plate c2; the solvent is then applied and the celluloid disc b is pressed into contact with the fabric, as indicated in Figure. 3.. Th@ celluloiddiscs may be applied on both sides of the fabric a if desired, as shown. in Figure 4. In either case the softened celluloid is Caused to penev`trate the fabric, resulting in an adherent structure, the section of which is shown in Figure 6. v

In thev case of a telephone receiver, the centre of the diaphragm A is provided with means for electromagnet operation, such as a disc d of soft iron, as seen in Figure 7, to form ay magnetic armaturesuitably secured in position b-y a rivet d1 and -washer d2 igure 8). i For gramophone sound boxes and the like, the stylus bar e is -connected to the' impregnated linen diaphragm LA (Figure 9) by I means of two washers or nuts e1 c2 upon av Central pin 'or rivet es passing ,through the diaphragm, as shownin' Figure 10, 4or kby means of a screw which pierces the diaphragm and is secured to the stylus bar.

I have found by experiment that dia- .phragms constructed' as above described pos- 'the ordinary type.' .By using Celluloid of ductions withl gramophone diaphragme of greater thickness than the textile the latter becomes entirely immersed Within the cellu-v,

loid.

Having thus described my invention, What I claim as such and desire to secure by Letters Patent is l. A vibratory diaphragm, composed of textile fabric stiffened byimpregnation with Celluloid by means of a solvent of the latter.

2. A vibratory diaphragm composed of linen applied to a sheet of Celluloid which is treated with a solvent of the latter and caused to penetrate the fabric.

3. A vibratory diaphragm, composed of textile fabric and Celluloid, said Celluloid being caused to impregnate said' fabric.

4. A vibratory diaphragm, composed of textile fabric and Celluloid, said Celluloid being softened by means of a solvent and While thus softened caused to impregnate said fabric.

5. A vibratory diaphragm, comprising a foundation of vtextile material and a layer thereinto.

6. A vib'ratory diaphragm, consisting of a -foundation of textile material, and a covering of Celluloid, said Celluloid being treated with a solvent and Caused to impregnate said textile material, being thereafter freed from said solvent byVV evaporation caused by drying. I 7. A diaphragm for the soundboxes of gramophones, comprising a' disc made of tracing linen, layers of Celluloid applied to both sides of said disc, said layers of celluloid being treated with aeroplane dope and subjected to pressure against said disc.'

In testimony whereof Lhereunto aiix my signature.

ARTHUR FREDERICK" RICHMOND COTTON.

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