Adjustable Ear Plug

Abstract

A flexible ear plug has flanges thereon of gradually increasing size. The plug can be inserted into an auditory canal after which the diameter of the flanges can be increased by forcing an insert into a cavity in the plug. One size plug, due to the variation in the diameters of the flanges and the fact that the diameters can be increased by use of the insert, fits all sizes of auditory canals.

Description

BACKGROUND OF THE INVENTION

As the general noise level has risen and as the noise level at specific locations has risen to tremendous heights, it has become more and more important to make available protection for the ears. A large variety of devices have been devised for this purpose. Most of these have consisted of a central portion shaped much like the interior of the auditory canal and have had flanges around them. Multiple flanges serve the purpose of sealing the auditory canal at more than one region against the entrance of sound. Many of the devices have passages therethrough so that some sound is allowed to pass. Such a channel also serves the purpose of equalizing the pressure in the auditory canal with that of the atmosphere.

The principle of expanding the inserted device in order to provide a tight fit between the device and the wall of the canal is exemplified in a number of designs. U.S. Pat. No. 2,824,558 shows a tapered cone and socket. The device has no flanges. Pushing in the inner cone causes the point of the outer cone to bulge. U.S. Pat. No. 2,876,767 discloses an inflatable ear plug without flanges, the purpose of which is to seal out water. U.S. Pat. No. 2,053,995 shows a hollow ear plug having a threaded screw in a socket which shortens the plug and increases its diameter. This device has no flanges thereon. It has a passage therethrough for the purpose of equalizing air pressure. U.S. Pat. No. 2,476,224 shows an ear plug designed to pass low intensity sound but to damp out high intensity sound. The device has a diaphragm therein.

All of these devices have features which appear to make them relatively effective for the purposes intended. However, the ultimate measure of the success of an ear plug is the attenuation achieved thereby. While a through-hole passing from the exterior end to the interior end of the plug has the advantage of equalizing air pressure it inevitably permits transit of sound energy therethrough, decreasing the effectiveness of the device. Consequently, it is necessary that means be provided for equalizing air pressure inside the autditory canal with atmospheric pressure without the use of a passageway. Also, it is highly desirable that a plug should be designed so that it fits all sizes of ear canals including those of children and adult men. Otherwise, it becomes necessary for the vendor to stock the material in a variety of sizes, this, in turn requiring a manufacturer to provide a variety of sizes so that the cost of the device is increased.

A second requirement of prime importance is that the device be comfortable. Otherwise it would be impossible for an individual who is to be exposed to loud noises for a lengthy period of time to continue to use the device. To achieve comfort, a tight seal between the device and the autditory canal must be accomplished without exerting undue pressure on the wall of the canal. The problem therefore presents itself of sealing an ear plug tightly against the wall of an auditory canal, preferably at a plurality of regions without exerting radial pressure beyond that which can be tolerated by the user for a substantial period of time.

SUMMARY OF THE INVENTION

An ear plug in accordance with the present invention is essentially a hollow rod, closed at one end, with a series of flanges graduated in size surrounding same. The flanges are sufficiently flexible so that the plug can be inserted into an ear of any size between that of a child and a male adult, the number of flanges entering the ear depending on the size of the auditory canal. The interior of the rod is preferably threaded and a relatively rigid screw can be inserted manually into the threaded portion of the ear plug. The screw is threaded into the rod by the user to a distance just short of that at which discomfort is felt.

In the process of inserting the plug into the ear canal, the plug is rocked from side to side to allow equalization of air pressure. Moreover, the cavity within the plug does not extend into the forward end thereof. The result is that the forward end remains flexible even after the screw is inserted; this makes it possible for the forward end of the plug to follow the natural curve of the auditory canal.

Accordingly, an object of the present invention is to provide an improved ear plug which is an effective attenuator of sound and which can be worn comfortably for extended periods.

Another object of the present invention is a flexible ear plug of a design such that one size fits virtually all sizes of auditory canals.

A further object of the present invention is to provide an improved ear plug having flanges which seal the auditory canal at a plurality of regions and in which the length of plug and diameter of the flanges can be increased after insertion of the ear plug into the auditory canal.

Still another object of the present invention is to provide an improved ear plug of a flexible, non-irritating material which can be molded in one piece.

Yet another object of the present invention is to provide an improved ear plug which provides the wearer with the option of balancing improvement in sound attenuation against comfort.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises an article of manufacture possessing the features, properties, and the relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWING

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a side view of an ear plug in accordance with the present invention in enlarged scale;

FIG. 2 is an end view of the ear plug shown in FIG. 1;

FIG. 3 is a sectional view of the same ear plug;

FIG. 4 is a side view of the insert used to expand the diameter of the ear plug;

FIG. 5 is a sectional view of another emebodiment of an ear plug in enlarged scale; and

FIG. 6 is a side view of a rigid screw which when threaded into the ear plug of FIG. 5 increases the diameter of said ear plug.

DESCRIPTION OF PREFERRED EMBODIMENTS

An embodiment of an ear plug in accordance with the present invention is shown in FIG. 1 and is indicated generally by the reference numeral 11. The inner end 12 of said ear plug is rounded to facilitate entry into the auditory canal. Said inner end 12 forms a flange 13 toward the rear thereof. The flange is tapered from the rear toward the front. The body of the device is essentially rod-like, the diameter of which corresponds to the position of the reference numeral 14. In the embodiment shown, flanges 13, 15 and possibly 15a are expected to be inserted into the ear canal, the ear plug 11 being of soft, elastic, non-irritating material. The diameter of the plug at 16 may be slightly larger than at 14 but this is not necessary.

In the embodiment of FIGS. 1, 2 and 3, only two flanges, namely those given the reference numerals 13 and 15, are expected to enter every ear. The diameter of flange 15 should be slightly larger than that of flange 13 and there may be further flanges as desired, each of successively larger diameter as the distance increases from tip 12. Flange 17 is purposely of sufficiently large diameter so that it cannot enter an auditory canal and thus serves as a stop against the possibility of inserting the plug so far into an unusually large auditory canal that difficulty may be had in withdrawing same.

To expand the ear plug an insert 18 is forced into the outer portion of the ear plug. The relationship of insert portion 18 to the outer portion is shown in end view in FIG. 2 and in sectional side view in FIG. 3 together with side view of insert 18 in FIG. 4. Insert 18 as shown in FIG. 4 has a head 19 which preferably is knurled or ribbed, a section 21 of constant diameter, a threaded section 22 and a conical end portion 23. A cavity in the outer member of ear plug 11 is indicated generally by the reference numeral 24; cavity 24 has a threaded section 26 for mating with threaded section 22 of insert 18. Threaded portion 26 ends in a tapered or frusto-conical section 27 leading to a section 28 having a diameter approximately the same as the smaller end of frustoconical section 27.

It will be noted from FIGS. 3 and 4 that the solid angle of frustoconical section 27 is greater than the solid angle of the conical end 23 of insert 18. As a result, when insert 18 is screwed into the cavity of the outer member, conical end 23 forces the walls of frustoconical section 27 and section 28 apart, thereby increasing the diameters of flanges 15 and 15a to the positions shown by the dashed lines 29 and 31. The wearer adjusts the degree to which flanges 15 and 15a are expanded by the extent to which he inserts insert 18. In general, insert 18 is used to increase the diameter of flanges 15 and 15a to the maximum extent compatible with comfort, thereby achieving the maximum attenuation of sound compatible with comfort.

It should be noted that cavity 24 ends at a region substantially short of tip 12, thereby providing a portion of the outer member which is sufficiently flexible to follow the curvature of the auditory canal, since the relatively rigid insert 18 does not reach into end portion 12.

During the insertion of ear plug 11, it is desirable to pull the top of the ear upward and rearward thereby straightening the outer portion of the auditory canal, and to rock the ear plug from side to side so as to provide momentary gaps between the flanges and the auditory canal, thus providing for equalization of the air pressure within the canal and the ambient air pressure. Otherwise, the seal achieved between the flexible flanges and the walls of the canal is sufficiently tight so that the air in that portion of the canal interior to the plug is compressed enough to make the wearer uncomfortable.

The ear plug is preferably made of silicone rubber, a material which is soft, elastic and non-irritating to the walls of the auditory canal. A preferred material is AGC-9248-2 a product having a methyl vinyl polysiloxane base manufactured by Stauffer-Wacker Silicone Corporation of Adrian, Michigan, 49221. This material is heat molded at about 350.degree.-375.degree.F for about 10 minutes. Suitable material for insert 18 are nylon, Teflon or other relatively rigid plastics.

Another embodiment of the invention is shown in FIG. 5 where the outer member of the ear plug is represented generally by the reference numeral 32. This embodiment has four flanges 33, 34, 35 and 36 of successively larger diameters. It has been found that a suitable diameter for flange 33 is about three-eighths inch and a suitable diameter for flange 36 is about one-half inch, successive flanges increasing in diameter by steps of about one-sixteenth inch. From one to four flanges may enter the auditory canal depending on the diameter of said canal. Fifth flange 37, on the other hand, is purposely made large enough so that tapered wall 38 will fit against the exterior opening of the auditory canal thus preventing insertion of flange 37 into the canal. A suitable diameter for flange 37 is eleven-sixteenths inch. In the embodiment of FIG. 5, threaded section 26 (FIG. 3) is replaced by a hexagonal nut 39 molded into outer member 32 as an insert during the molding process. The hexagonal exterior of nut 39 prevents rotation of same during insertion of insert 41 (FIG. 6). Cavity 42 has a frustoconical section 43 and a section 44 of constant diameter essentially equal to the smaller end of frustoconical section 43. Tip 52, of cavity 42 falls well short of tip 47 of outer member 32. Consequently the forward portion of the ear plug is flexible even when insert 41 is completely inserted into cavity 42. This section is preferably about one-fourth inch in length and provides for conforming of the inner end of outer member 32 to the auditory canal of the wearer. It will be noted that the diameters of flanges 33 and 34 are not appreciably affected by the insertion of insert 41.

Insert 41 is preferably of nylon or Teflon and has a threaded portion 49 of constant diameter. This threaded portion may be viewed as being frustoconical with a solid angle equal to zero. From this point of view, frustoconical section 43 of cavity 42 has a larger solid angle than portion 49 of insert 41.

As insert 41 is threaded into nut 39, the diameter of flange 36 is first increased and then the diameter of flange 35. The diameter of flange 34 is changed only to a relatively small extent. As tip 51 of insert 41 reaches the narrow end of frustoconical section 43, the length of outer member 32 begins to increase simultaneously with increase in the diameter of flange 36. The increase in length continues as insert 41 penetrates cavity 42. Threaded portion 49 is purposely made longer than the depth of cavity 42. In addition, when tip 51 of insert 41 meets bottom 52 of cavity 42, if rotation of insert 41 is continued, the length of outer member 32 is still further increased. This increase in length forces flanges 34 and 33 further into the auditory canal giving a further measure of tightening of the flanges against the wall of the auditory canal. As aforenoted, the forward or inner end of the outer member is not penetrated by the relatively rigid insert so that said inner end can follow the curvature of the auditory canal.

After use of the ear plug of the present invention, removal of the insert 41 from the outer member makes it easy to remove the plug from the ear due to the decrease in the diameter of the flanges. It is advisable to rock the plug from side to side during removal to avoid producing a decrease in pressure inside the auditory canal. The plug can be reused any number of times and if made of a soft, elastic material having a sufficiently high melting point, can be sterilized if desired.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above article without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Claims

What is claimed is:

1. A sound-attenuating device adjustable in outer diameter for insertion into the exterior opening of the auditory canal comprising an outer member of a soft, elastic non-irritating material, said outer member having an outer diameter such that it can readily be inserted into an auditory canal and having an interior end and an exterior end, said member further having an essentially axial cavity therein open only at the exterior end thereof, and an inner member of an essentially rigid material adapted for insertion into said outer member at said exterior end with interference between said inner member and the wall of said cavity, the relative dimensions of said inner member and the wall of said cavity being such that as said inner member is forced into said outer member at said exterior end, the exterior diameter and the length of said outer member are increased to an extent which is a function of the distance to which said inner member is inserted into said outer member, thereby enabling a user to adjust said device for maximum attenuation of sound compatible with comfort, said device being adjustable in size over a range such that a single model fits any normal auditory canal.

2. The device in accordance with said claim 1 wherein said outer member is internally threaded and the exterior of said inner member is threaded for mating with the thread in the interior of said outer member, adjustment of the exterior diameter of said outer member being obtainable by rotation of said inner member relative to said outer member.

3. The device in accordance with claim 2, wherein said inner member has on the outer end thereof an element which is adapted for grasping for convenient rotation of said inner member.

4. The device in accordance with claim 3, wherein said element is a knurled or ribbed knob.

5. The device in accordance with claim 1, wherein said member has at least one flexible flange about the exterior thereof, said flange being located intermediate the ends of said member at a position such that forcing said inner member into the cavity in said member increases the diameter of said flange.

6. The device in accordance with claim 1, wherein said member has a flange at the exterior end thereof sufficiently larger than auditory canals to limit the extent to which said member can be inserted into a canal.

7. The device in accordance with claim 1, wherein the interior of said outer member and the exterior of said inner member are both essentially conical or frustoconical and the solid angle of said inner member is smaller than that of said interior.

8. The device in accordance with claim 1, wherein said cavity in said member has an intermediate frustoconical portion of a solid angle greater than the solid angle of said inner member and an end portion of approximately the same diameter as the smaller end of said intermediate frustoconical portion, said end portion serving to facilitate distension of said outer member and reception of said inner member as said inner member is forced into said outer member.

9. The device in accordance with claim 1, wherein said outer member is of silicone rubber and said inner member is of nylon.

10. The device as defined in claim 1, further comprising a nut of relatively rigid material within said cavity, the axis of said nut coinciding with the axis of said cavity, and wherein said cavity has an intermediate frustoconical section and end section, the larger end of said frustoconical section being adjacent said nut and having approximately the same diameter as the root diameter of the thread in said nut and said end section of said cavity having approximately the same diameter as the smaller end of said frustoconical section, said frustoconical end sections of said cavity being on that side of said nut closer to said interior end of said outer member.

11. The device as defined in claim 10, wherein said inner member comprises a threaded portion of constant diameter and said inner member is of length great enough to penetrate into said end section of said cavity, said threaded section being adapted to mate with said nut.

12. The device as defined in claim 10, whrerein said nut is of nylon and said outer member of molded silicone rubber with said nut as an insert proximate the exterior end of said outer member.

13. The device as defined in claim 12, wherein said outer member is of a molded silicone rubber having a methyl vinyl polysiloxane base.

14. The device as defined in claim 12, wherein said outer member has a plurality of flanges thereon, the outermost of said flanges being large enough to seat against that portion of the ear proximate the opening of the auditory canal, successive flanges in the direction of the inner end of said device each being of smaller diameter than the preceding flange, each flange being essentially frustoconical with the smaller end toward the inner end of said outer member.

15. The device as defined in claim 14, wherein said outer member is sufficiently longer than said cavity so that at least one of said flanges and a portion of said outer member lie beyond the inner end of said cavity, threreby providing that said relatively rigid inner member cannot penetrate at least one of said flanges and making it possible for a portion of the inner end of said outer member to conform to the normal curvature of the auditory canal.

16. The deviece as defined in claim 10, wherein the diameter of the smallest of said plurality of flanges is about three-eighth inch, the diameter of successive flanges increases by about one-sixteenth inch, the diameter of the largest of said flanges is at least eleven-sixteenth inch, the root diameter between the innermost and next innermost flanges is about three-sixteenth inch, and the length of said outer member is about twenty five-thirty seconds inch.