US1665284A - Acoustic diaphragm - Google Patents

Description

April l0, 1928 J. Q. sLYE ET AL ACOUSTIC DIAPHRAGM Filed Deo. 16, 1926 w O W T of Q :S75/e MH Patented Apr. 10, 1928.

UNITEDSTATES PATENT OFFICE.

JOHN Q. SLYE AND RICHARD/H. COFFBEN, 0F WASHINGTON, DISTRICT OF COLUMBIA.

ACOUSTIC DIAPHBAGM.

Application llled December 16, 1926. Serial No. 155,220.

This invention relates to improvements in sound reproducing instruments and more particularly to a nove'l diaphragm for' talking machines, loud speakers and the llke.

With a view of improving sound reproduction instruments and to obtain better results, various kinds of diaphragms lhave been devised. Some of these are made up of laminated layers. The present invention relates more specifically to diaphragms of the last mentioned type.

One of the objects of the invention is to provide a diaphragm made up of at least three layers, each playing an important part with tone vibrations in musical records and the like. One layer preferably consists of double-faced satin, and this is combined with a second layer of thinly rolled' tin foil, these two layers combining to give rich tone quality to the music and dampening the metallicrin usually present in talking machines an ythe like. The third layer preferably consists of a circular piece of cork which modifies the great friction which is usually aociated with talking machine records.

Wth the foregong objt voutlined and with other objects in view which will appear as the description proceeds, the invention consists in t e novel features hereinafter described in detail, illustrated in the accompanying drawing, and more particularly ointed out in the appended claims.

Re erring to the drawing:

Fig. 1 is a face view of a standard talking machine reproducer provided with the'y improved diaphragm.

Fig. 2 is a vertical sectional view taken on line 2-2 of Fig. 1. l

Fig. 3 is an enlarged vertical sectional view of a portion of the diaphragm, to clearly illustrate the arrangement of the layers.

In the drawing, 1 designates a talking machine reproducer, which may be of any preferred construction, to be combined with the improved diaphragm, the latter being connected to the usual stylus 3.

As best shown in Fi-g. 3, the diaphragm forming the subject matter, of this invention consists of a layer 4.- of textile fabric. We have found in practice that doublefaced brown satin is particularly suitable for. our purpose, owing to its appearance and` construction. Arranged at the rear of the fabric layer, is a layer 5 of thin metallic foil, preferably tin foil, and arranged rearwardly of this layer is a third layer of dampening material, such as cork. This layer is of smaller size than the other 2 60 layers to permit free vibration of the diaphragm.

In manufacturing this diaphragm, the three layers, while in a flexible condition are pressed together and dried by heat, and in actual practice, we have built u a diaphragm of this character, in the ollowing way:-

We used one thin circular piece of cork 1% inch in diameter; one circular layer of 70 tin foil of larger diameter rolled ver thinly; and one layer of double-face satin treated on both sides with quick drying French varnish. The layers were superposed, and adhesive placed between the tin 7h oil and cork, and then the laminations were pressed together and dried by heat. The resulting diaphragm was placed in a reproducer casing and was found to produce improved' results, re roducing sound 4more 80 Shar ly and softly t an the diaphragm now on t e market.

From the foregoing it is believed that the method of manufacture, and thenimproved construction may be clearly understood, and it is obvious that changes may be made in the details disclosed Without departing from the s irit of the invention as expreed in the c aims.

What is claimed and desired to be secured 9o by Letters Patentis:

1. A laminated diaphragm for sound re producers comprising at least three layers, one layer of textile fabric, one of metallic foil, andV one of sound dampening material, and adhesive securing said layers together.

2. A laminated diaphragm for sound reproducers comprisi ff at least three layers, one layer of textile abric, one layer of metallic foil, and one layer of cork, the cork 10o Q 1 ,emee

layer being of smaller diameter than the formed of (zoek, and the intemeiete teg/e11- other layers, and. adhesive seeming said layformed of tmoil,` and adhesive securing said 10 ers together. layers together.

3. A. laminated diaphagm for soulld ren testimony whereof we mx om'i signe.-z

5 prouees compgismg et least three layers, tures,

one outer layer formed of double-faced satin coated on both sides with veemsh7 the JOHN SLYE. other outer ayer being of smaller size and RECHARD H. COFFREN.

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