US2893011A - Sound attenuator helmet - Google Patents

Description

W. S. FlNKEN ETAL SOUND ATTENUATOR HELMET July 7, 1959 2 Sheets-Sheet 1 Filed Sept. 24, 1954 INVENTORS WALTEQ 6. F/A KE/V JAc/(so/v A. A/MQ y 1959 w. s. FINKEN ET AL SOUND ATTENUATOR HELMET 2 Sheets-Sheet 2 Filed Sept. 24, 1954 INVENTORS M41759 6. F/A/KZA BY mc/rsm A. AVAFO Ed-9% M Arm/WE! some other physical process. attenuator is used herein as a generic term ll'lClUdlDg any United States Patent SOUND A'ITENUATOR HELMET Walter S. Finken, Brooklyn, N.Y., and Jackson A. ileo, Carbondale, Pa., assignors to Leonard P. Fneder, Great Neck, N.Y.

Application September 24, 1954, Serial No. 458,094

' 5 Claims. (Cl. 2-3) 'llhis invention relates to sound attenuators generally, and more specifically, it is concerned with a specially adapted sound attenuator which may be used with a helmet or cap arrangement, in order to reduce the noise level as required in special instances.

The principal mechanisms for the attenuation of sound are absorption and reflection. Absorption commonly takes place when a sound wave encounters a soft, rough surfaced material, so that the wave is scattered and its energydissipated in the material. Reflection commonly takes place when a sound wave encounters a hard, smooth-surfaced material. Reflection may not measurably reduce the total energy in an impinging wave. Nevertheless, if a reflecting surface is placed between the source of a wave and a point where the intensity ofthe wave is to be measured, that surface effectively reduces the wave intensity at that point. Reflection occurs, to some extent, at any interface between materials of different densities.

The term, sound attenuation, as used herein, is intended to include generically any reduction in the intensity or energy level of sound waves, whether that reduction is accomplished by absorption, reflection, or Similarly, the term sound means effective at a given measuring point, e.g., the ears of a person, for reducing the intensity or energy level of sound waves emanating from a source, e. g., a jet .engine, at a. different locality.

In certain fields of endeavor, notably in aircraft-carrier deck operations, under modern conditions, the noise level, encountered may quite considerably exceed a safe limit for human ears. This is especially true in connection with modern aircraft such as jet-type craft where the personnel working with and near a craft during carrierdeck operations is exposed to the very high energy noise level created by the engines of such aircraft.

The apparatus according to this invention may be employed in conjunction with conventional ear plugs or the like if desired. However, under most circumstances, the attenuators disclosed by this invention are adequately effective to obviate the use of any additional sound-attenuation devices such as cotton'wads in the ears, or the a like.

' high noise levels with safety.

Another object of this invention is to provide a compact and effective arrangement for attenuating sound by employingsound-absorbing as well as sound-reflecting layers directly over the ears of the wearer. Briefly, the invention includes a supporting element or cap, and sound-attenuating means supported thereby over the ears of a wearer. Themodification of the invention disclosed herein includes a close-fitting head covering cap having a chin strap attached thereto, first sound attenuator means for encircling the ears, and second sound attenuator means for covering the ear within said earencircling means. The second sound attenuator means preferably includes a relatively hard sound-reflecting layer as well as a fibrous sound-absorbent layer and a sound-absorbent cellular layer. The apparatus of the invention further includes strap means cooperating with the chin strap for pressing the ear covering sound-attenuator means into intimate contact with the ear-encircling means and with the wearers ears, and for pressing the ear-encircling means into engagement with the wearers head.

The foregoing and other objects of the invention will become apparent from a consideration of the following specification and claims, taken together with the accompanying drawings.

In the drawings- Fig. l is a side elevation showing a helmet embodying a sound attenuator according to this invention;

Fig. 2 is a front elevation of the same helmet and sound attenuators;

Fig. 3 is an enlarged cross-sectional view of one of the sound attenuators taken along the line 3-3 of Fig. 1;

Fig. 4 is a side elevation of a different embodiment of a sound attenuator according to this invention, partly broken away to show the interior construction in a sectional view similar to Fig. 3; and

Fig. 5 is a longitudinal cross-sectional view similar to Fig. 3, taken centrally through still another embodiment of a sound attenuator according to this invention.

It will be appreciated that the sound attenuators according to this invention might be arranged in any convenient manner to be supported in place over the wearers ears. However, it has been found that a light material, closefitting cap in the nature of a helmet is readily adaptable to act as a supporting means for the attenuators. In this connection it is to be noted that for the most eflicient operation of the attenuators, it is necessary to apply some force tending to press the attenuators, particularly the central portions thereof, against the wearers head, with some pressure 'being applied to the outer surface of the wearers ears. The helmet disclosed herein is provided with straps over the attenuators that cooperate with the chin strap of the helmet in a manner to be presently described to accomplish the application of the necessary force and pressure.

Like reference numbers will refer to like parts throughout the various figures of the drawings.

Figs. 1 to 3 There is a close fitting cap or helmet 11 illustrated in Figs. 1 and 2 that may be constructed of any desirable material depending upon the conditions under which the wearer is intended to operate While wearing the same. The helmet illustrated is particularly well adapted for the use of personnel attending aircraft operations aboard a carrier or the like, and for warm weather the cap may have open-mesh panels as illustrated which may be in the nature of the panels particularly described in our copending application Serial No. 382,048, filed September 24,

1953. A chin strap 12 is attached at one end thereof to the helmet 11 in any suitable manner as by stitching. A readily disconnectable attaching device such as a snap fastener 13 is mounted on the free end of the chain strap 12, and is attachable to a mating snap fastener 13a (Fig. 2). The chin strap is adjustable as to length in any convenient manner, as by means of a buckle 14 illustrated. In this manner the size of the chain strap may be adjusted to the individual wearer in order .to hold the lower edges of hehnet 11 snugly against the face so as to produce a desired pressure against the head of the wearer in a manner to be presently described.

A strap 15 extends centrally over the outside of each attenuator, and may be fastened to the helmet at either end thereof in any convenient manner as by stitching, illustrated. The straps l cooperate with the chin strap 12, when the chin strap is adjusted and fastened, to produce an inward force on the attenuators against the head of the wearer. Such action will be very clear upon an inspection of the view illustrated in Fig. 2. This inward pressure may be additionally adjusted as desired by means of any convenient adjustment mechanism such as a buckle 16 illustrated, see Figs. 1-3. Each attenuator is composed of a number of elements and is generally indicated as a unit by reference numeral 1'7.

The attenuators 17 may take various forms. A preferred embodiment is that illustrated in Figs. 1, 2 and 3, the details of which are clearly illustrated in Fig. 3. The ear-encircling element may take the form of a torus or doughnut-like element 18. This doughnut-like element 18 includes a cover 18a composed of a material having a soft felt-like exterior and formed in a tube by stitching 19 along an edge of the material as shown. The doughnut-like or torus element 18 is filled with any desirable fibrous material 20, e.g., kapok. The torus element 18 forms a soft, sound absorbent, somewhat elliptical ring which is pressed against the head of the wearer encircling each ear in order to create a good sound seal and also to relieve the wearers outer car from undue pressure thereon.

The ear-covering element of attenuator 17 comprises a reflecting plate 21, a thin inner pad 24, and a thick outer pad 25. The doughnut element 18 is attached to the plate 21, which is formed of plastic material that is relatively stiff. Such material may be a stiff grade or rubber or the like. This plate 21 is shaped to fit over or receive a portion of the doughnut element 18. The plate 21 may be covered on the outside by a layer of cloth 22 to match the cloth employed in the construction of the helmet 11. Cloth layer 22 is preferably cemented or glued to the relatively stiff plate 21. The plate 21 with its cloth covering 22 is attached to the helmet 11, in any convenient manner such as by means of stitching 23 completely around the edges of the plate 21, as illustrated in Fig. 1. Within doughnut-like element 18 and beneath the plastic plate 21, i.e., next to the wearers car, there is a thin pad 24 having a cover 24a next to the wearers ear that is preferably constructed of the same or similar soft felt-surface material as the cover 18a. This pad 24- may be fastened in place in a convenient manner such as for example by stitching at the edges onto the surface of the doughnut element 18 as illustrated. This pad 24 may also be glued to the inner surface of the plastic plate 21 if desired, and the pad is filled with a fibrous material such as kapok, for example.

Located outside the plastic layer 21 with its cloth covering 22, is a generally oval-shaped sound attenuator pad 25. This pad 25 may be constructed in any convenient manner but is illustrated as having a cover 25a of cloth with stitched seams 26 as necessary. The pad cover 25a is preferably glued or cemented onto the fiat surface within the shaped portion of plate 21 above the cloth surface 22, in order to hold the whole pad 25 in place in case the strap 15 is loosened. Also when the helmet is not on the wearers head the pad 25 should be secured to the helmet in order not to be separated from the helmet. Within the pad cover 25a there are located two separate layers of different materials, one of which is a single layered cushion 27 which may be constructed with a cloth exterior and filled with fibrous material such as kapok. Above the cushion 27 (when viewed as shown in Fig. 3) and within the pad 25 there is a dual layer of cellular material 28 which may be any spongy or cellular material in the nature of sponge rubber or the like. This cellular material 28 may be made up of a single layer of material but it is preferred to construct this layer of two separate elements which are glued together or otherwise held in intimate contact at one face of each. By using material such as sponge rubber and ha ing a smooth surface, such as may be gained by vulcanizing or the like, some reflection of sounds of certain frequencies may be obtained at such smooth surfaces.

Fig. 4

Fig. 4 illustrates a somewhat different embodiment of an attenuator according to this invention, and the elements which are different will be described.

In this embodiment the ear-encircling element 18 is attached to a comparable plate 29 of plastic material that compares with plate 21 above, but does not extend across the area inside of doughnut element 18. Instead, plate 25 is in the form of an oval-shaped ring leaving an opening at the center thereof over the wearers car. In this embodiment, a strap 30 corresponds to the strap 15 of the previously-described attenuator helmet, but there is in addition a snap fastener 31 at one end of the strap 30 in order to be able to unfasten and fold back the central portion of the attenuator in a manner to be described. The strap 30 is fastened to the helmet in a permanent manner at the right hand end thereof, as it appears in Fig. 4, which end is preferably above the attenuator when in place on the wearers head. The strap 30 passes through a pair of loops 32 that are securely fastened centrally on the outside of a casing 33 of plastic material.

The casing 33 partially encloses the ear-encircling element of the attenuator in Fig. 4, and is shaped to correspond to the hole on the central portion of the doughnut 18 and fits snugly therein in a manner illustrated in Fig. 4. The casing 33 may be constructed of any suitable rigid but flexible plastic material; and has fastened across the inside thereof a cover 34 composed of cloth or the like. Within the lower portion of the casing 33 and adjacent the cloth cover 34 there is a relatively thick layer of fibrous material 35 which may be kapok or the like. In the upper portion of the casing 33 there is a layer of cellular material 36. The cloth cover 34 may be attached to casing 33 in any secure way, c.g., by gluing or cementing a strip of cloth 37 around the outside of the bottom edge of the casing 33 and then stitching cover 34 to the strip 37 as illustrated in Fig. 4.

In use, the embodiment according to Fig. 4, may be shifted from a sound attenuating condition to a condition of no attenuation, without removal of the helmet 11 from the wearers head. Such a shift may be accomplished by disconnecting the snap fastener 31 and then folding back the strap 30 so as to lift out the whole casing 33 with its attached parts and leave the wearers ear exposed. By proper arrangement of the parts of snap fastener 31 on each of the pair of attenuators that are attached to the helmet 11, the snap fasteners could be attached to one another over the top of the wearers head so as to hold both casings 33 and connected elements out away from the cars. In this manner the wearer may rapidly apply the attenuators to his ears as desired while conveniently carrying the equipment handy and ready for use at all times. At the same time the wearer may have his hands free and his person relatively unencumbered.

Fig. 5 illustrates another embodiment of an attenuator according to this invention, which embodiment comprises an annular ear-encircling element 40 and a central earcovering element 47. The element 40 includes a frame 41 of plastic material. Frame 41 has a flange 41a by means of which the attenuator may be attached to the cap or helmet 11 in any convenient manner such as by, stitching. Located on the outside of the frame 41 there is a pair of loops 42 for holding a strap (not shown) such as the strap 15 of Figs. 1 through 3. The element 40 is covered on its outer side by a cloth cover 43 and on its inner side by a cloth cover 44 which may be constructed of cloth having a soft felt surface corresponding to the surface of doughnut element 18 of the other embodiments. The covers 43 and 44 are stitched together at 43a. Contained within the annular frame 41 of the upper portion thereof, as viewed in the drawing, there is an annular layer 45 of cellular material, such as sponge rubber or the like beneath which is located a layer 46 of fibrous material that may be kapok or the like.

The central ear-covering element 47 comprises a thin casing 48 having a dish-like shape. This casing is preferably constructed of a relatively stifi plastic material such as rubber or the like. Within this dish-like structure 48 there is a disc-shaped layer 49 of cellular material such as sponge rubber or the like. A layer 50 of fibrous material, such as kapok, is located below (as it appears in Fig. 5) the layer 49 of cellular material. The lower boundary of fibrous layer 50 comprises a sound-reflecting layer 51 made of any relatively hard material, e.g., metallic foil or the like. Beneath this reflecting layer 51 there is a soft cloth layer 52 that may be constructed of a felt or other soft-surfaced cloth which will rest against the wearers ear with least discomfort.

It will be observed that an attenuator according to this invention is an extremely efiective device for cutting down the energy level of sounds reaching the wearers ear, and is comfortable when worn for long periods of time.

While there have been described specific embodiments of the invention, these are not to be taken as in any way limiting this invention but merely as being descriptive thereof.

It is claimed:

1. Sound attenuating apparatus comprising a support adapted to fit over a wearers head, a pair of sound attenuating devices, each adapted to fit over one ear of the wearer when the support is in place on the head, each device comprising an annular plate of relatively stiff material attached at its edges to the support and adapted to encircle the wearers car, an elliptically annular pad attached to the inner side of the plate and extending inwardly therefrom, said pad having internal dimensions large enough to encircle the ear, an elliptical pad shaped peripherally to conform with the internal dimensions of the annular pad and the annular plate, means supporting said elliptical pad within said annular pad and plate, said pads being formed at least in part of compressible material, and compressing strap means for each device, means fixedly securing spaced portions of each said strap means to said support at spaced localities on opposite sides of its associated sound attenuating device, each said strap means having an intermediate portion between said spaced portions, which intermediate portion extends across and engages the outwardly extending portion of said associated sound attenuating device, each said strap means including length adjustment means by which the compression of each said sound attenuating device may be independently varied with respect to each other.

2. Sound attenuating apparatus comprising a support adapted to fit over a wearers head including a crown portion, side portions fixed to opposite sides of the crown portion, and a chin strap connecting said side portions, said crown portion, said side portions and said chin strap cooperating when in place to extend circumferentially around the wearers head, said chin strap including length adjustment means by which said support may be tightened on the head to bring said side portions into close engagement therewith, a pair of sound attenuating devices each adapted to fit over one ear of the wearer when the support is in place on the head, means attaching one of said devices to each of said side portions with portions of the devices extending outwardly from each said side portion, said devices being formed at least in part of compressible material and comprising strap means for each device, means fixedly securing spaced portions of each said strap means to one of said side portions at spaced localities on opposite sides of its associated sound attenuating device, each said strap means having an intermediate portion between said spaced portions, which intermediate portion extends across and engages the outwardly extending portion of said associated sound attenuating device, each said strap means including length adjustment means by which the compression of each said sound attenuating device may be independently varied with respect to each other and with respect to the tightening of said support.

3. Sound attenuating apparatus as defined in claim 1, in which said elliptical pad extends outwardly beyond the support and beyond the annular pad and is engaged by the compressing strap means.

4. Sound attenuating apparatus as defined in claim 1, including means for removably supporting the elliptical pad within the annular pad to close the central opening therein, said removable supporting means comprising means on the outer side of said elliptical pad for receiving said intermediate portion of said strap, the fixedly securing means for said strap means at one of said spaced portions being disengageable to permit removal of said elliptical pad from said opening.

5. Sound attenuating apparatus as defined in claim 2, in which each said sound attenuating device includes a plate of relatively stiff plastic material attached at its edges to said support and extending over the wearers car, an elliptically annular pad attached to the inner side of the plate and extending inwardly thereof, said pad having internal dimensions large enough to encircle the ear, and an elliptical pad shaped peripherally to conform with the internal dimensions of the annular pad, said elliptical pad being mounted no the outer side of said plate and projecting outwardly therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 1,354,524 Timmons Oct. 5, 1920 1,456,524 Waldron May 29, 1923 2,593,892 Kindel Apr. 22, 1952 2,684,067 Lienard July 20, 1954 FOREIGN PATENTS 210,875 Great Britain Feb. 11, 1924 598,030 Great Britain Feb. 9, 1948 UNITED STATES AT N 'QE I CERTIFICATE OF. CORRECTION Patent No. 2,893,011

v v it July 7, 195" Walter S. Finken et ale It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent shouldreadas corrected below.

Column 3, line 35, for "grade or" read e grade of I column 6;, line 48, for "mounted no" read mounted on ---Q Signed and sealed this 3rd day of May 1960,

(SEAL) Attest:

KARL H. AXLINE 3 ROBERT C. WATSON Attesting ()fiicer Commissioner of Patents

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