The subject matter disclosed herein relates to earplugs and a method of assembling an earplug.
Hearing protection devices (HPDs) may be broadly categorized into earplugs, which are placed into or against an entrance of an ear canal of a user to form a seal and block sound (insert or semi-insert), earmuffs, which fit over and around the ear (circumaural) to provide an acoustic seal against the head, and helmets, which normally encase the entire head of the user. Earplugs are typically made from materials such as slow-recovery closed-cell foam, vinyl, silicone, elastomer formulations, spun fiberglass and cotton/wax combinations. They may be grouped into the categories of foam earplugs, pre-molded earplugs, formable earplugs, custom molded earplugs and semi-insert earplugs.
Foam earplugs are generally made from either slow-recovery PVC or polyurethane closed-cell material, both of which provide similar amounts of sound attenuation. PVC earplugs are commonly punched from sheets of foam to have simple contours with parallel sides and cylindrical or hexagonal footprints. Polyurethane earplugs are molded to have shapes like bullets or bells and may have asymmetrical features like ridges. Since their introduction, foam earplugs have become widely used because they are generally comfortable to wear and they provide a high degree of amount of sound attenuation. They can, however, be difficult for some users to insert fully and properly.
Pre-molded earplugs, on the other hand, are formed from flexible materials, including foam, into conical, bulbous or other shapes and are typically affixed to or enshroud a flexible stem for handling and insertion. Users can, therefore, grip the stem and push the earplugs into place in the ear canal whereupon an acoustic (pneumatic) seal is made against the canal walls.
Foam earplugs or pre-molded earplugs can, therefore, be used by students taking tests who want to have an amount of ambient sound attenuated or by musicians in concert, flight deck personnel or employees on the floor of a manufacturing plant who are exposed to extremely loud sounds that would otherwise impair their hearing after prolonged exposures. In each case, the effectiveness of the earplugs depends greatly on the amount and types of sounds that are attenuated, the comfort users experience when the earplugs are worn, the ability of the users to insert their earplugs safely into their ear canals and the ability of the users to remove their earplugs safely when desired.
Often, however, the factors that relate to the effectiveness of earplugs can be in conflict with one another. For example, an earplug whose tip is very dense may attenuate a large amount of sound but may also be very uncomfortable to wear. Meanwhile, an earplug that is less dense may be very forgiving but may not attenuate a sufficiently large amount of sound and could be difficult to insert properly. Similarly, an earplug that comes equipped with a relatively stiff stem may be easy to insert into an ear canal, but the same earplug may be dangerous if the stem were subject to an impact that forced the earplug deep into the ear canal.
According to one aspect of the invention, an earplug is provided and includes a tip for use in forward and lateral sealing, which is formed to define a rearward recessed cavity, and a stem, including a user graspable elongate portion configured with a stiffness in a first direction that is greater than a stiffness in a second direction, which is transverse to the first direction, and a member, disposed at a forward end of the elongate portion and configured to be insertable into the cavity, wherein the member includes a surface to be adhered to an interior facing surface of the cavity and on which a channel is defined to allow for outflow from the cavity, and the member is formed with a shape to complement that of the cavity to axially and circumferentially align the tip and the stem.
According to another aspect of the invention, an earplug is provided and includes a tip for use in forward and lateral sealing, which is formed to define a rearward recessed cavity, and a stem, including a user graspable elongate portion configured with a stiffness in a first direction that is greater than a stiffness in a second direction, which is transverse to the first direction, and a member, disposed at a forward end of the elongate portion, which is configured to be insertable into the cavity with axial and circumferential alignment and to be adhered to an interior facing surface thereof.
According to yet another aspect of the invention, an earplug is provided and includes a tip for use in forward and lateral sealing, which is formed to define a rearward recessed cavity, and a stem, including a user graspable elongate portion, and a member, disposed at a forward end of the elongate portion and configured to be insertable into the cavity, wherein the member includes a surface to be adhered to an interior facing surface of the cavity and on which a channel is defined to allow for outflow from the cavity, and the member is formed with a shape to complement that of the cavity to axially and circumferentially align the tip and the stem.
According to yet another aspect of the invention, a method of assembling an earplug is provided and includes forming a tip for use in forward and lateral sealing, boring a rearward recessed cavity into the tip from a rear face thereof, forming a stem with a biaxial stiffness including an elongate portion, and a member, disposed at a forward end of the elongate portion and configured to be insertable into the cavity, defining a channel along a surface of the member, aligning the member with the cavity, and adhering the surface of the member to an interior facing surface of the cavity with outflow from the cavity being urged along the channel.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
With reference to
The sound attenuating material of the tip 20 may be polymer foam or the like and has a normal non-deformed diameter, d1, which is generally wider than a width of an ear canal for a human being. For the small minority of people (2-10% of the general population) whose ear canals are either relatively narrow or relatively wide, d1 can be decreased or increased. Thus, the tip 20 can be provided so as to fit snugly in the ear canal of most people with the polymer foam acting as an acoustic or pneumatic sealant against undesirable noise levels.
In accordance with embodiments of the invention, the polymer foam has a density range between about 5 to about 20 lb/ft3 with an optimum density range of about 9 to about 15 lb/ft3. Thus, the polymer foam is easily deformable by the user and tends to rebound following the deformation. In this way, the tip 20 may be inserted with appropriate force into the ear canal whereupon the polymer foam adaptively responds to the shape and the size of the ear canal interior and freely articulates with respect to the stem 30.
The adaptive response of the tip 20 to the shape and size of the ear canal interior can be manifested as inward and outward deformations of the polymer foam that arise from pressure applied to the tip 20 by the ear canal walls. The free articulation of the polymer foam can be manifested as radial deformations of the polymer foam that arise from torsion forces applied by the user in opposition to frictional forces present between the ear canal walls and the exterior surface of the tip 20.
The tip 20 is formed with a forward portion 21 of sound attenuating material and lateral portions 22 of sound attenuating material. As such, the forward portion 21 of the tip 20 provides sealing to the ear canal of the user in the forward, SF, sealing direction as the tip 20 is inserted into the ear canal. Similarly, the lateral portions 22 of the tip 20 provide sealing to the ear canal in the lateral, SL, sealing directions. With reference to
As shown in
As will be discussed below, the tip 20 may be formed with variable shapes and/or designs. For example, the tip 20 may resemble a piston with the forward portion 21 resembling a piston dome. Further, the tip 20 can include additional design elements, such as wrist pin bores 103, ring lands and grooves 104 and piston dome features 105 (see
With reference to
With reference to
Referring back to
The member 50 is the component of the stem 30 that is inserted into the cavity 26 when the earplug 10 is assembled. The member 50 generally extends integrally from the flange 40 along a longitudinal direction in parallel with that of the stem 30. The member 50 includes a surface 51 that is to be adhered to the sound attenuating material of the tip 20 that is located at the interior facing surface of the cavity 26 when the member 50 is inserted therein. An adhesive, such as Loctite 403 glue, can be used to cause the surface 51 to adhere to the interior facing surface of the cavity 26.
A channel 60 is defined as a crevice in the surface 51 and may run along the longitudinal length of the member 50. The channel 60 allows for an outflow of air and excess adhesive from the cavity 26 when the member 50 is inserted therein. The channel 60 may be provided as a single channel or, more commonly, as a pair of channels disposed on opposite sides of the member 50. Of course, it is to be understood that still further additional channels 60 can be provided on the surface 60. Moreover, the cavity 26 can also include channels of its own.
While the channel 60 is illustrated as being straight, it is to be understood that the channel 60 may have various shapes and sizes that are either regular or irregular. For example, the channel 60 could be straight, as shown in
With reference to
In detail, as shown in
Conversely, as shown in
With the member 50 and the cavity 26 having complementary shapes that axially and circumferentially align the tip 20 and the stem 30, the earplug 10 is further provided with increased structural stability. That is, with the respective shapes of the member 50 and the cavity 26 complementing one another, a potential for relative rotation between the stem 30 and the tip 20 when the user rotates the stem 30 during, e.g., the insertion of the tip 20 into the ear canal, is reduced. In this way, while the exterior of the tip 20 may freely articulate with respect to the stem 30, once the earplug is removed from the ear canal or reoriented therein, the tip 20 will be urged to rebound to its original form.
In addition, the complementary shapes of the member 50 and the cavity 26 provide stability to the earplug 10 while the adhesive bonding the surface 51 of the member 50 to the cavity 26 sets. This allows the member 50 and the cavity 26 to be aligned with one another for appearance purposes. With the tip 20 and the stem 30 so aligned, the achievement of an accurate rod and piston design, for example, is promoted.
In accordance with an embodiment of the invention, as mentioned above, the member 50 and the cavity 26 are extendable through the tip 20 and beyond at least a center of mass, CM, 90 of the tip 20 such that an end of the cavity 26 and the distal end 52 of the member 50 are disposed between the CM 90 and the forward portion 21 when the member 50 is inserted into the cavity 26. This configuration tends to prevent undesirable deformation of the tip 20, such as a folding of the tip 20 over itself.
This configuration also increases an ability of the sound attenuating material of the tip 20 to acoustically seal the ear canal. When the tip 20 is inserted in the ear canal, the member 50 acts as a relatively rigid central body that impinges against the sound attenuating material of the tip 20 in opposition to the forces applied by the ear canal walls upon the sound attenuating material in an inward direction. The opposing forces counterbalance one another and increase the acoustic sealing provided by the tip 20. Thus, with the distal end 52 of the member 50 disposed between the CM 90 and the forward portion 21, a relatively large amount of the forces applied by the ear canal walls are counterbalanced by the extension of the member 50 into the tip 20. At the same time, the presence of the forward portion 21 of the tip 20 increases user comfort by protecting the inner components from abutment with the relatively rigid structure of the member 50.
As mentioned above, the flange 40 serves to delimit a boundary between the elongate portion 31 and the member 50 and extends in an outward radial direction from the forward end of the elongate portion 31 and a rear end of the member 50. The flange 40 is generally positioned such that the member 50 is sufficiently long to fully inhabit the cavity 26 when the member 50 is installed therein. Also, the flange 40 serves as an additional surface for adhesion to the tip 20 or, alternately, to deflect the outflow of excess adhesive flowing along the channel 60 from the cavity 26.
In accordance with an embodiment of the invention, the tip 20 and the stem 30 may be formed to resemble any desired image. In particular, where the earplug is intended for use in an automobile manufacturing plant, the tip 20 and the stem 30 can appropriately resemble a rod and piston combination. Here, as mentioned above, the tip 20 may include design elements, such as wrist pin bores 103, ring lands and grooves 104 and piston dome features 105, while the stem 30 may include design elements, such as rod faces 101 and rod structural features 102. Of course, such designs are merely exemplary and other shape and size options are available.
In accordance with further embodiments of the invention, the biaxial stiffness of the stem 30 is directed such that the lateral direction, DL, and the normal direction, DN, are circumferentially aligned with at least one of the circumferential position of the channel 60 around the member 50, the arrangement of the complementary shapes of the member 50 and the cavity 26 and/or the exterior appearance of the tip 20 and the stem 30. That is, where the stem 30 is less relatively stiff in the normal direction, DN, the surface 51 of the member 50 may have channels 60 defined thereon in alignment with faces 36 and 37 and off-phase with respect to sidewalls 34 and 35. In this way, outflow of air and/or excess adhesive can be promoted by a simple bend of the stem 30 in the normal direction, DN. Similarly, where the complementary shapes of the member 50 and the cavity 26 are aligned with the normal direction, DN, the likelihood that the tip 20 and the stem 30 be misaligned during assembly may be reduced. Finally, the exterior appearance of the tip 20 may be irregular or, for example, the tip 20 may have oval cross-section that corresponds to the shape of an ear canal. In such a case, having the normal direction, DN, be aligned with the long axis of the tip 20, may encourage the user to take advantage of the oval shape of the tip 20 while inserting the earplug 10 into his/her ear canal by bending the stem 30 only about the faces 36 and 37 and the long sides of the tip 20.
In accordance with yet another aspect of the invention, a method of assembling an earplug is provided and includes forming a polymer foam tip 20, for use in forward and lateral sealing with a rearward recessed cavity 26, forming a stem 30 with a biaxial stiffness including an elongate portion 31, and a member 50, and inserting the member 50 into the cavity 26. The member 50 is disposed at a forward end of the elongate portion 31 and is configured to be insertable into the cavity 26. The member 50 includes a surface 51 to adhere to an interior facing surface of the cavity 26. A channel 60 is defined on the surface 51 to allow for outflow from the cavity 26 when the member 50 is inserted therein. The member 50 is formed with a shape to complement that of the cavity 26 to axially and circumferentially align the tip 20 and the stem 30 when the member 50 is inserted into the cavity 26. The inserting of the member 50 into the cavity 26 is achieved such that adhesive adheres the surface 51 to the interior facing surface of the cavity 26 and such that outflow proceeds from the cavity 26 along the channel 60.
In an alternate embodiment, the stem 30 is held with the member 50 placed in a given position. The polymer foam of the tip 20 is then formed around the member 50 such that the polymer foam adheres to the surface 51 of the member 50. Here, the flow channel 60 allows air exhausted from the formation of the polymer foam, to flow out from the cavity 26.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
This application is a continuation of U.S. Ser. No. 29/337,641 filed May 27, 2009, now abandoned the disclosure of which is incorporated by reference in its entirety herein.
Number | Name | Date | Kind |
---|---|---|---|
D124880 | Teunisz | Jan 1941 | S |
3005564 | Weichselbaum | Oct 1961 | A |
3020333 | Bangert et al. | Feb 1962 | A |
3850361 | Day et al. | Nov 1974 | A |
D237853 | Katz | Dec 1975 | S |
D247160 | LaCroce et al. | Feb 1978 | S |
D248873 | Raitto | Aug 1978 | S |
D254446 | Raitto | Mar 1980 | S |
D265129 | Leight | Jun 1982 | S |
D267429 | Harada | Dec 1982 | S |
D267512 | Carlsson et al. | Jan 1983 | S |
4375016 | Harada | Feb 1983 | A |
4541377 | Amos | Sep 1985 | A |
4576430 | Dufresne | Mar 1986 | A |
D321128 | DeBose, Jr. | Oct 1991 | S |
5074375 | Grozil | Dec 1991 | A |
5080110 | Weldon et al. | Jan 1992 | A |
D372070 | Zak et al. | Jul 1996 | S |
5564431 | Seward | Oct 1996 | A |
D377493 | Oda | Jan 1997 | S |
5607152 | Strassburger | Mar 1997 | A |
D398531 | DeVries | Sep 1998 | S |
D399212 | Roderweiss | Oct 1998 | S |
D412118 | Rodea | Jul 1999 | S |
D432604 | Scheiner | Oct 2000 | S |
D435330 | Soergel | Dec 2000 | S |
6226865 | Tanikawa et al. | May 2001 | B1 |
6234812 | Ivers et al. | May 2001 | B1 |
D443259 | Okubo | Jun 2001 | S |
D444141 | Koss et al. | Jun 2001 | S |
6252164 | Wise | Jun 2001 | B1 |
D445694 | Gans | Jul 2001 | S |
D445774 | Matsuoka | Jul 2001 | S |
D451401 | Silvers et al. | Dec 2001 | S |
6439413 | Prevot et al. | Aug 2002 | B1 |
D462185 | Sandy | Sep 2002 | S |
D463392 | Khadivar | Sep 2002 | S |
6457969 | Khosla | Oct 2002 | B1 |
D466995 | Knauer et al. | Dec 2002 | S |
D467363 | West | Dec 2002 | S |
D479832 | Homewood et al. | Sep 2003 | S |
D486815 | Jones | Feb 2004 | S |
D489007 | Hall et al. | Apr 2004 | S |
D497191 | Shore | Oct 2004 | S |
D500021 | Hu | Dec 2004 | S |
D512409 | Ishizaki | Dec 2005 | S |
D518728 | Frantz | Apr 2006 | S |
D519870 | Pritchard | May 2006 | S |
D521637 | Yang | May 2006 | S |
D523345 | Kamineni | Jun 2006 | S |
D524655 | Baez | Jul 2006 | S |
D526564 | Slavin et al. | Aug 2006 | S |
D526981 | Kim et al. | Aug 2006 | S |
D528213 | Darley et al. | Sep 2006 | S |
D529822 | Munn | Oct 2006 | S |
D531056 | Ioannides et al. | Oct 2006 | S |
D531517 | Hillard | Nov 2006 | S |
D531586 | Poulet | Nov 2006 | S |
D532400 | DeZhang | Nov 2006 | S |
D536262 | Ioannides et al. | Feb 2007 | S |
D536264 | Ioannides et al. | Feb 2007 | S |
D538361 | Sato | Mar 2007 | S |
D538600 | Jennewein et al. | Mar 2007 | S |
D542153 | Farrow et al. | May 2007 | S |
D542656 | Szczesniak | May 2007 | S |
D546706 | Ioannides et al. | Jul 2007 | S |
D549596 | Ioannides et al. | Aug 2007 | S |
D554603 | Murakami | Nov 2007 | S |
D559382 | Sanpei | Jan 2008 | S |
D561715 | Sugiyama | Feb 2008 | S |
D561732 | Motoishi | Feb 2008 | S |
D562987 | Colin et al. | Feb 2008 | S |
D564824 | Henry | Mar 2008 | S |
D568743 | Kunesh et al. | May 2008 | S |
D569253 | Cracchiolo | May 2008 | S |
D572206 | Ikeda et al. | Jul 2008 | S |
D575427 | Nelson et al. | Aug 2008 | S |
D578394 | Shurtleff et al. | Oct 2008 | S |
D581286 | White | Nov 2008 | S |
D581289 | Westphal | Nov 2008 | S |
D582285 | Cracchiolo | Dec 2008 | S |
D584152 | VerWeyst et al. | Jan 2009 | S |
D585402 | Shimizu | Jan 2009 | S |
D585558 | Feeley et al. | Jan 2009 | S |
D586666 | Lucido | Feb 2009 | S |
D587378 | Powers et al. | Feb 2009 | S |
D588936 | Ioannides et al. | Mar 2009 | S |
D590055 | Butler et al. | Apr 2009 | S |
D592300 | Yeh | May 2009 | S |
D593858 | Kubicek et al. | Jun 2009 | S |
D594117 | Patzer et al. | Jun 2009 | S |
D595268 | Kolton | Jun 2009 | S |
D595837 | Benner | Jul 2009 | S |
D596500 | Diss et al. | Jul 2009 | S |
D596956 | Diss et al. | Jul 2009 | S |
D596957 | Diss | Jul 2009 | S |
D599829 | Jorgensen | Sep 2009 | S |
D599907 | Mulvey et al. | Sep 2009 | S |
D603715 | Serrano Diaz | Nov 2009 | S |
D604611 | Ames et al. | Nov 2009 | S |
D605172 | Seade | Dec 2009 | S |
D606050 | Nousiainen | Dec 2009 | S |
D608767 | Liner | Jan 2010 | S |
D611344 | Longacre | Mar 2010 | S |
D611821 | Gabrielsson et al. | Mar 2010 | S |
D611835 | Chou Huang | Mar 2010 | S |
D611929 | Blanchard | Mar 2010 | S |
D612249 | Wurster et al. | Mar 2010 | S |
D613862 | Vue et al. | Apr 2010 | S |
D614049 | Diss et al. | Apr 2010 | S |
D614955 | Diss | May 2010 | S |
D616747 | Stull et al. | Jun 2010 | S |
D616979 | Falco | Jun 2010 | S |
D617191 | Stull et al. | Jun 2010 | S |
D620366 | Bruscha et al. | Jul 2010 | S |
D620377 | Diss | Jul 2010 | S |
D621030 | Falco | Aug 2010 | S |
D621271 | Soni | Aug 2010 | S |
D622591 | Biesecker et al. | Aug 2010 | S |
D622837 | Falco | Aug 2010 | S |
D623286 | Falco | Sep 2010 | S |
D627019 | Martin | Nov 2010 | S |
D633196 | Falco | Feb 2011 | S |
D641465 | Falco | Jul 2011 | S |
20040129276 | Kuno et al. | Jul 2004 | A1 |
Number | Date | Country |
---|---|---|
18732 | Aug 1952 | CA |
568217 | Sep 2006 | EM |
WO 2004021941 | Mar 2004 | WO |
Number | Date | Country | |
---|---|---|---|
20100300460 A1 | Dec 2010 | US |
Number | Date | Country | |
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Parent | 29337641 | May 2009 | US |
Child | 12781159 | US |