US1740651A - Ernst hxteter - Google Patents

Description

Dec. 24, 1929. E, HUETER 1,740,651

SOUND GENERATOR Filed Jan. 30. 1925 5" ksr-W- -H- aw+ ,Z'nvenow EYnS Hllefer 1749.2'. .2 //Q, mm

'45 of the system.

Patented Dee. 24, .1929 l UNITED STATES PAT-ENT Aorriciz' ERNST HUETER, oF DARMSTADT, GERMANY soUND GENERATOR The present invention refers to diaphragms which, for practical reasons ,'are mainly used as generators, viz fiat or differently shaped objects, actuated mechanically or by elec.-

6 tricity. Such generator diaphragms have the disadvantage-of not reproducing speech and music accurately, for instance, owing to distortion. These distortions are principally due to the resonance propensities of the 10 regular diaphragm, inasmuch ason one hand,

sound frequencies near the natural frequency of the respective diaphragm are, relat1vely,

reproducedmuch louder than sounds beyond this zone; and on the other'hand, the natural '15 vibrations of the object rise above the forced,y

i. e. the intended vibration. All of this is based upon the fact that the diaphragm has a mass, as well as resettingpower, and thus becomes a. vibrating system (a diaphragm actuated in one'direction'by the impulse to be reproducedA and in the oppositedirection by the resiliency ofthe diaphragm).

That is to say, if t-he mass of the diaphragm is great, resonance makes the energy required to oscillate the diaphragm large and a large force is necessary to return the diaphragm.

after it is deflected. If the weightof the diaphragm can be made small, the requiredresetting force inherent in the diaphragm may be correspondingly small. The diaphragm thus requires a smaller force to operate, it may be less rigid, and

made thinner.

The object of the present invention is the 'creation of a diaphragm showing a non-pronounced resonance curve, i. e. one as flat as.

possible, in order to warrant a better reproduction', as free from distortion as possible, thereby causing a quicker succession of the 40 natural vibrations. fAccordingto the invention this end is gained bythe reduced weight 'of the vibrating system, whereby the resetting power Amay be reduced in the same degrec, without changing the natural frequency Generally' speaking, the natural frequency of a system serving as a generator, unless one is willing to stand a number of drawbacks, must be near the center of the register of speech frequencies.. -.According to the present invention, by the specific construcaccordingly may be ApplicationY tiled January 30, 1925', Serial No. 5,8327, and in Germany Ianuaryr'22, 1924.

tion of the diaphragm, one succeeds iu greatly reducingtlie weight of the system, and at the same time in retaining such anamount of the resetting poweras to keep the natural frequency of the diaphragm less pronounced within the desired zone, which leads to Aan improved -reproduction of the sound.

The diaphragm of the invention consists of a (lattice) network, so arranged as to have ,a relatively large expansion vertically to the so diaphragm plane, and upon which, as a working diaphragm, a homogeneous material is placed, in order to secure -the'required {irmness',v at the smallest weight. l j The annexed drawing shows a generator diaphragm corresponding to the invention, in

two forms:

Fig. 1 is a v'ention.

Fig. 2,is a cross sectional view on line 2.-2 70 ofFigl.A Y Fig. 3 is a lan vie7 of a' second form ot my invention taiien on line .3 3 of Fig. 4. Fig. 4 is a cross sectional view of the second form of my invention on' line 4 4 of Fig. 3 75 with the Vupper plate removed to facilitate illustration.

In the form shown in Figs. land 2, the diaphragm consists of plate 1, to which a number of reinforcing stays 2 have been attached. so These stays need not be arranged symmetrically. They may be placed irregularly, thereby obtainingv a greater number of d- -visional natural frequencies. A .reinforcing plan view of one form of my inring 3 is provided about the periphery of said 85 A diaphragm. i

A diaphragm with a relatively great resetting power, of light weight, is produced by employing the` principles'of my invention. Iron foil, for instance, may be used for the v90 material of the`diaphragm, as this willobviate an incr'ease in the eflicient weight, wlii hI would follow through additional iron plates'f-s orfother armature needed Vwherever the diaphragm is actuated by magnetic power. If in such case the foil is not strong enough to receivethe magnet-ic power lines, it may be reinforced by additional layers, in the respetive place, or by using heavier foil from the beginning. f

'l One form osuch arrangement is shown in F i`gs..3 and 4. The dia hragm consists of plates 4 and', made o suitable material," which plates areseparated by network 5., and.

reinforcing ring 8.-

The coverings for itself is very {lightinweight In one ot tlie preferred forms of the :inventionpthe plate'lV is made of'a thin woodlayer with Wooden A slats. lIn Fig. 3 the plates 4 and 6 are'thin wooden layers and the lattice work 5 and the riml8 are of Woodor otherlight Weight porous Y material. I have obtained successful 'opera-,

tionwith' thejplates 4 and 6 constructed of palfr and the. lattice work 5 and rirn 8 .of cor Such diaphragms, Awithout great increase in Weight, may be made large enough to dispense with anA acoustic horn or amplifier to `secure the-required sound effect.

Claims:` '1. A sound reproducer having a diaphragm'comprising a shect'of elastic material and `aplurality of reinforcing members of porous material and a second sheet of elastic material secured to said reinforcing members in spaced relation to saidffirs't mentioned sheet anda rim'member connecting the p'e- Q* inforcing mem ripheries of each of said sheets and prede- Y termining the spacial relation thereof.

2. A soundrcproducerhaving*a diaphragm comprisingala er of Wood, a plurality of reliefs-'extending at angles to each other across said .diaphragm and a see- -ond layer of wood mounted on said reinfor ing members in spaced relation to .said first mentioned'layer of wood and a rim member 'connecting the peripheries of said layers and o predetermining the spacial relation thereof.

. In testimony whereof I affix my signature.

ERNST HUETER.

o the lattice work are thin, homogenous and elastic and the lattice work

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