US834629A - Diaphragm for transmitting sound-waves. - Google Patents

Description

No. 834,629. PATBNTEB 0011.30, 1906.

E. H. MOBLBY. DIAPHRAGM Foa TRANSMITTING SOUND WAVES.

APPLICATION FILED SEPT. 17. 1903.

ELI'QIY Wim/55555: [Nl/ENTOR narran strates ramena ernten.

EDWlN H. MOBLEY, OF MORTON, PENNSYLVANlA.

DIAPHRAGM FGF@ TRANSMlTTlNG SQUNDeWAVES.

no. senese.

Specification of Letters Patent.

,Patented oct. so, ieee.

Application filed September 17, 1903. Serial No. 173,501.

T0 all whom, it may concern:

Beit known that i, EDWIN H. MOBLEY, of Morton, Delaware county, State of Pennsylvania, have invented an Improvement in Diaphragme for Transmitting Sound-Waves, of which the following is a specification.

One of the difficulties which has been met in preserving the clearness and distinctness as well as the natural tone or timbre of sounds transmitted by vibratory diaphragme has been due to the fact that, owing to the construction of the diaphragm, it assumes a more or less curved or arched position while vibrating under the action vof the soundwaves, which results in the deflection of the sound-waves and their consequent interference with one another.

if the diaphragm, or that portion of it which is eective in the transmission of the sound-waves, vibrates in the plane of its surface, or without curvature in the diameter of its plane, the Waves will not be deflected, but will be transmitted in direct lines. While this result can'and possibly has been obtained in diaphragms of special construction where the central vibratory portion has been connected with the clamping edge or outer support by separate connectingsprings, such constructions are unsatisfactory not only because of their complicated and expensive construction, but also because the openings afforded by these spring connections permit a portion of the sound-waves to pass through without acting on the diaphragm. Not only are such sound-waves lost, but the openings permit air-currents to pass throu h, which affect the sound-Waves transmitte by the vibrations of the diaphragm.

a diaphragm composed of a single integral sheet without openings or attenuated portions'in which the central part may vibrate under the action of the sound -waves Without appreciable curvature in the lines of its diameter or plane of its surface.

The diaphragm is formed of a thin sheet of strong resilient material, having its central portion united with the clamping edge by an integral, continuous, and unattenuated spring portion of substantial width, so that the central portion is strengthened or stayed against curvature and the radial movements necessary to permit the vibrations are taken up in the integral uniting spring portion.

The diaphragm may be used in any instru- It is the object of my invention to provide yvibrations are transmitted, is connected with the outer edge l), by which the diaphragm is clamped in place, by an integral spring portion c. This Vspring ortion c is of substantial width, so as to al ow for sulicient movement during the vibration of the central portion to enable the said central portion to maintain a flat uncurved surface. This is illustrated in dotted lines in Fi 2, from which it will be seen that the radia motion is taken up entirely inthe portion c, andthe central operative 'part a is not arched or bent, as is Athe case with integral diaphragms as they have 'heretofore been constructed. v

The practical effect of thus maintaining the centralpor tion of the diaphragmin a flat un# curved condition duri-ng its vibrations is to transmit the sound-.waves at right anglest the face of the diaphragm and not to deflect them laterally, as wouldv be the case if they pere transmitted by a curved or arched sur 3.06. mitted are more' clear and distinct and their natural quality or timbre is more perfectly preserved. v

d is an annular corrugation about the center" of the diaphragm at a substantial distance from the outer edge, and h represents a series of radial corrugations extendingfrom the center of the diaphragm to said annular corrugation. These radial corrugations form the central stiifened vibratory portion, and the spring portion c is-between the annular corrugation d and the outer edge. A vsecond annular corrugation dpmay be formed near the outer edge, the spring portion c being theflat uncorrugated annulus between said corrugations d and d. y

'Attention is particularly directed to the fact that the diaphragm is composed. of a single integral piece of uniform thickness and that'the spring connection. between the central portion and supporting edge, which pre- By reason of this the sounds trans-1 ICO IIC

serves the fiat position of the Central portion during the vibrations, `is formed without weakening or reducing the metal.`

The diaphragms mayI be stamped or spun np.

What I claim as new, and desire to secure by Letters Patent, is as follows:

1. A diaphragm for transmitting soundwaves consisting of a thin sheet of strong resilient material, having an annular corrugation near the outer edge, a smaller annu ar oorrugation within said outer oorrugation, and a series of radial eorrugations extending from the .center of the diaphragm to said smaller annular oorrugatiomsaid small annular oorrugation and radial corrugationsforming a Central stiffened vibratory portion, and the annular portion between said annular corrugations forming a resilient connecting portion between the stiened center and the outer edge 2. A diaphragm for transmitting soundwaves consisting of a thin sheet of strong resilient material having an annular corrugation about the center at a substantial distance from the vouter edge, and a series of radial oorrugations Vextending from the center of the diaphragm to said annular corruga tion, said oorrugations forming a central stiffened vibratory portion.

In testimony of which invention I hereunto set my hand.

EDWIN H. MOBLEY.

Witnesses:

ERNEST'HOWARD HUNTER, M. J. EYRE.

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