US1016704A - Diaphragm. - Google Patents

Description

F. B. MEECH.

DIAPHRAGM.

APPLICATION FILED 0011.4, 1910.

1,016,704. mama Feb.6,1912.

I WITNESSES [WENT R W BY ATTORNEY FRANK ".8. MEECH, (3F LJEW YGHK. :33. Y.

'IJIAPHRAGlvI.

Specification of Letters Patent. ""1; @n'l'intll 1 6 i t5. 1%}12,

Application filed October 4, 1910. Serial No. 585,975.

To (ZZZ trim-m '1' 6 may concern,

Be it lcnoivn that l. Fnmzu li. Min-mu. a citizen of the United some. residing at Ken: York. in the county and State of New York.

have invented new and useful lmprouunents in Diaphragms, of which the following a speci tication.

This invention relates to sound apparalus where sound vibrations are received from or transmitted to a diaphragm.

More particularly the invention relates to a dia 'ihragm where. voice or musical sound vibrations are received or utilized. such vibrations or Waves being compounded frcnn many individual sound sources or 00711130 nen't vibrations, and. resulting in a complicated or intricately composed ave. If the diaphragm does not respond exactly to the wave form in all its detail and complication, the purity of the sound Will he lost.

One of the objects of the. present invention is to provide adiaphragm of such a character that the sound purity will be preserved; in other words in which the sound Wave will be received or utilized Without changing its characteristics, even in the more minute or complicated details of sound wave form.

So far as l ain aware, diaphragms have hitherto b8( i made on the principle of securing Inerelyhigh elasticity; mica glass, copper, aluminum or other similar sonorous substances being examples. Such materials by virtue of their jelastic and sonorous character seem to he and are adapted to ve cer tain acoustic results. So far as Iain aware the effort at inniroveInQnt has hitherto been constantly in the direction of obtainingmaterials inore elastic and more vibratile or sonorous in character than those hitherto utilized, and the latest developments are in the direction of mica as being a. material having the above characteristics most prominently inherent in it.

Itis one of the objects of the present in vention to utilize new principles of action which have not been hitherto considered as having any hearing, or relation, and by'utilining such new principles to provide an improved diaphragm.

The invention relates to an improved diaphragm in its various aspects.

To this end the invention cons material employed and in the co ructions and combinations as hereinafter setforth.

in the drawings, Figure l, is a perspective view of a diaphragi'n eniihodying the prineiplu'agrm:

is a. similar a modified form oil diu- 3 and l, illustrate further modili-z .l igrs. and (l. are rcspec tively sectional and front. views of another modifi d form of diaphragm mlmdving the invention, and Fi e. T, shows diagramnuiiirally the use of a diaphragm in asound 1'11" cording or reproducingapymratu The invention will include a cellular diaphra e'ni of'a material which is light in 'sveicjht. in accordance with the principles of vibration and motion, the inertia or weight of anything acted upon tends to produce a lag between the cause and el .l; 0. between action and the motion resi-lting from the action. 'The reducii'ig of the pies o'l my invention: Fist. 2, View sl weight is therefore a matter of importance,

which, however, is related to other matters of equal importance. A second principle or attribute of my diaphragm. flexibility, meaning flexibility in ditl'erent. Ways or directions. A third principle or attribute uniformity in any elastic stress or strain put on the material by any deformation. A.

fourth principle or attribute of the present;

diaphragm is absence of vicosity, the ideal material being one which recovers its -origi nal form instantly when the deforming 'influence is removed. A fifth principle or attribute that the factors above mentioned 27. c. flexibility uniform elasticity and absence of vicosity mnst be present particularly in deformations hi the diaphragm be tween narrow ranges or limits of movement or deformation, rather than between wide limits, in order to suit the microscopic char actor of actual sound vibration.

In order to find a material satisfying the,

ahve principles and requirements, I have conducted experiments and have discovered that cork "when out in sheet form and made into a diaphragm gives results which are not only siuierior to any results hi thei'to olotained, but are markedly different. in character, particularly with reference to the purity ofthe sound received or utilized. The invention will therefore in its best form include cork in the form of a diaphragm as A in Fig. 1. The actual forms, details and arrangementof the cork diaphragm may be varied. The cork may he in its natural state. or may be compr :d. or it; may be treated or used in prepa 'ations known as composition cork. It may be cut in thin sheets A. Fig. 1. or thick sheets l3. 2. It

made in unitary construction asin'llig. 1, or

in sectional construction, as shown in Figs] 5 and 6. in these figures there is provided a plurality of sectors or sections grouped around a common center and associated into unitary'forni by cement or otherwise.

The diaphragm may have a thickened rim portion asl Fig. 3, either integral or separately applied. it may be made of tWo sheets or sections such as E and F l? ig. t cemented together so as to cure the naturalporosity of a plain corlrsheet.

The essential physical characteristic of my improved diaphragm Which distinguishes it from other diz'lphragins hitherto used, .is that it has a very light comparatively honiogene' 011s cellular structure. .ln addition to this there is the further characteristic that its tension in a given median plane of vibration Wholly dependent on its own resiliency, or in other Words not dependent on outside factorssuch as metal plates.

The microscopic cellular structure of n y diaphragm is such that it is almost perfectly elastic to recover itself from deformation through a minute deflection, although when considerably deformed it does not appear to be elastic: and does not recover itself promptly. This is due to the cellular charactor of the cork, the cells being very much like a mass of bubbles of very small size and uniformly homogeneous in all planes. A very small deflection does not bend or crush any of the Walls between the cells, Which 'alls are exceedingly thin and delicate. The vibration on the other hand is a true vibra- W tion, and the recovery of the cork is doubtless due to the air in the cells as Well as the resiliency of their delicate cellular Walls.

In accordance With'my present diaphragm the stiffness is secured not by tensioning the diaphragm, but by making it quite thick, for example or of an inch in thickness.

In Fig. 7 I hiive shown diagrammatically one use of the diaphragm in a sound box for sound recording and reproducing purposes. 1 denotes the sound box; 2 the diaphragm therein, and 3 the means or stylus connected to said diaphragm for transmitting sound vib -ations. V

\Vhile l have described certain forms of diaphragm I do not desire to be particularly limited or restricted to the particular constructions shown, since variations may be made within the principles of the invention,

'without departing from the spirit or scope thereof.

hat I claim is:'-

A diaphragm for sound recording and reproducing apparatus comprising a disk or plate of natural cork permanently cemcnte to a similar disk or plate of natural cork, said plates of cork being adapted to transversely stiffen one another throughout. their entire area.

in testimony whereof, I have signed my name to this specification in the presence of two subscribing W tnesses, this 3rd day of Cctober 1910.

FRANK B. MEEGl-l.

"Witnesses GRACE T. Dixon, ALFRED W. Pnoo'ron.

Images