Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF THE INVENTION
The present invention relates generally to a
wax guard system and more particularly to a system for
preventing ear wax from entering the sound channel and
receiver of "in the ear" or "canal" type hearing aids.
Many hearing aids include a shell that holds
the components of ~he hearing aid and rests within the
ear canal of a user. The components include a receiver
and a sound channel interconnecting the receiver and
shell. Electrical signals representative of the sounds
are sent to the receiver by other components within the
hearing aid, and the receiver responsively creates
sound. The sound travels from the receiver~ through the
sound channel and shell, to the user's ear canal and ear
drum.
; The ears of most users naturally secrete a
substance referred to as cerumen or earwax. While -the
earwax tends to clean the interna~ structure of an ear,
it also tends to flow into the sound cbannel and
2~ receiver of the hearing aid. Upon reaching the
receiver, the earwax interferes with, or prevents,
proper operation of the receiver.
Consequently, the hearing aid may require
complete disassembly so that the receiver may be cleaned
or replaced. Of course, bringing the hearing aid to a
service center ~or such disassembly is both inconvenient
and expensive for the user.
Unfortunately, presently available systems
are poorly suited to guard against earwax buildup in the
sound channel and receiver of a hearing aid. Some
hearing aids, for example, have no protection against
earwax. Other conventional systems may use a rigid
.g.,. . ~ ~
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metal screen that is ineEfective in stopping the flow of
earwax into the receiver and must be carefully cleaned
periodically with a special toolO
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SUMMARY 3F THE INVENTION
In a principal aspect, the present invention
is a wax guard system for a hearing aid~ The hearing
aid includes a shell having both an interior surface
about a cavity defined by the shell and an exterior
surface which is exposed to a region that is external to
the hearing aid.
The shell also includes a hearing aid port
between the exterior and interior surfaces. Moreover, a
receiver, having an output port, rests within the
cavity. A sound channel interconnects the output pork
of the receiver and the hearing aid port so that sound
may travel from the receiver to the external region.
The sound channel defines a centerline and a cross-
sectional dimension substantially perpendicular to thecenterline.
The wax guard system includes a pliant, porous
s ructure, referred to as a ~Iguard~ inserted into the
hearing aid port. The guard substantially allows sound
to pass from the sound channel to the external region.
Moreover, the guard substantially prevents earwax from
flowing from the external region into the sound channel.
The pliant guard has a cross-sectional
dimension greater than the crs~ss-sectional dimension of
the sound channel. In addi~ion, a retainer ring is
affixed to the hearing aid port between the pliant guard
and external region. The retainer ring defines an
aperture having a cross-sectional dimension less than
the cross~sectional dimension of the pliant guard. As a
result, the retainer ring retains the pliant guard
within the hearing aid port~
;
Thus, an object of the present invention is an
improved wax guard system Eor hearing aids. Another
object is a wax guard system that is more e~:Eective and
less expensive.
Still another object is a wax guard system
that uses a more pliable and saEe guard. In adclition,
an object is a wax guard system that uses a guard which
collects wax and thereaEter may easily be removed,
disposed of, and replaced with another guard.
BRIEF DESCRIPTION OF THF, DRAWING
FIGURE 1 is a perspective view of the hearing
aid shell and receiver used with the present insention;
FIGU~F. 2 is a cross-sectional view ~taken
substantially along line 2-2) of the preferred
embodiment of the present invention of FIGURE l; and
FIGU~E 3 is an enlarged cross-sectional view
(taken substantially along line 3-3) of the sound
channel, pliant guard, and retainer ring of the
preferred ~mbodiment shown in FIGURE 2.
3~
DETAILED DESCR PTION OF THE PREFERRED EMBODIMENT
Referring to FI~URES 1-3, the preferred
embodiment of the present invention is shown as an.
improved wax guard system, generally desiynated 10, for
"in the ear" or "canal" type hearing aids, illustra-
tively designated 12.
Such hearing aids often include a pl.astic
housing or shell 14. The shell 14 includes an interior
surface 16, exterior surface 18, and hearing aid port
1~ 20. The interior surface 16 defines an interior cavity
22 of the shell 14.
The exterior surEace 18 is exposed to a region
24 that is external to the hearing aid 12. The hearing
aid port 20 extends between the interior and exterior
surfaces 16, 18 of the shell 14. The port 20 is
cylindrically shaped, having a length between the
internal and external surfaces 16, 18 of approximately
.060 inch and a diameter of about oll0 inch.
In the pr~ferred embodiment, the interior
cavity 22 of the shell 14 contains components for the
hearing aid 12S such as a receiver 26, sound channel 28,
and filler material 30~ The receiver 26 includes a
protuberant output port 32. Sound is emitted from the
receiver 26 through its output port 32. The filler
materia:l 30 substantially fills a portion of the
interior cavity 22 and cradles the receiver 260
The sound channel 28 is a hollow, substan--
tially cylindrically~shaped passageway. The sound
channel 28 interconnects the output port 32 of the
receiver 26 with the hearing a:id port 20. It may be
formed, for example, either by a tube or, as in the
preferred embodiment, by the absence of filler material
30 between the output port 32 and hearing aid port 20.
The sound channel 28 ~efines a centerline 34
between the output port 32 of the receiver 26 and
hearing aid port 20. The centerline 34 is in the very
midd:Le of the sound channel 28 and is shown as being
straight. The sound channel 28 may be formed in a
variety of non-straight shapes, of course and the
centerline 34, extending down the middle of the sound
channel 28 would then also assume a non-straight shape.
In the preferred embodiment shown in FIGURE 3,
the cross section of the sound channel 2g is
perpendicular to the centerline 34 and has a pre-
determined, circular shape. The diameter of the
circular shape is approximately .050 inch.
The wax guard system also includes a pliant,
porous structure, hereinafter referred to as a porous
guard 36 and retainer cup or ring 38. The pliant guard
36 is comprised of a cylindrical disk of open cell
polyurethane. While a large variety of such foams will
prove suitable for use with the present invention,
applicants have discovered that Scott Industrial Foam
manufactured by the Foam Division of the Scott Paper
Company, 1500 East Second Street, Chester, Pennsylvania
19013l functions satisfactorily.
Such foam having a density of approximately 80
pores per inch has been found acceptable. The foam is
capable of allowing sound to pass therethrou~h without
substantial interEerence and still resist the flow of
wax therethrough n Moreover, the soft, light pliable
nature of the foam makes it well-suited for use within
the human ear. Even if dropped within the ear, its
pliability will substantially resist irritating or
abrading the skin or structures within the ear~
Moreover, the ~oam is chemically inert~ Thus it is
not adversely affected by body aclds, perspiration, cr
mild soaps.
In the preferred embodiment, the cylindrical,
pliant guard 36 has a thickness (between the interior
and exterior surfaces 16, 18 of the shell 14) of
appro,ximately .030 inch. The pliant guard 36 also has a
diameter (or cross-sectional dimension) of approx-
imately .080 inch.
The plian~ guard 36 is inserted in the hearing
aid port 20 abu~ting both the sound channel 28 and
filler material 30 within the interior cavity 22 of the
shell 14. Since the pliant guard 36 has a cross-
sectional dimension (diameter) O030 inch larger than the
cross-sectional dimension (diameter) of ~he sound
channel 28, the pliant guard 36 resists moving into the
sound channel 28 or output port 32 of the receiver 26.
The entire retainer ring 38 has an outside
diamelter o roughly .lL0 inch and is af~ixed to the
hearing aid port 20 substantially between the pliant
guard 36 and external region 24. The retainer ring 38
may be permanently affixed by gluing it in the hearing
aid port 20 with a strong glue 40 such as a cyano-
acrylate ester.
In the preferred embodiment, the retainer
ring 38 is a unitary, substantially ring-shaped device.
For purposes of illustration, however, the retainer ring
38 may~ be considered as having both an upper region 42
adjacent the sound channel 28 and filler material 30 and
a lower region 44 adjacent the external region 24. The
upper region 42 is approximately .030 inch thick (which
is roughly the same thickness as the pliant guard 36)
and defines a central aper-ture 46 that is approxirnately
.080 inch in diameter (which is roughly the same
#~
_g_
diameter as the pliant guard 36). Thus, the pliant
guard 36 lies wil:hin the central aperture 46 of the
upper region 42 of the retainer ring 38.
The lower region 44 of the retainer ring 38
abuts the upper region 42 and is also approximately .030
inch thick. The lower region 44, however, deEines at
least one central aperture 48 that is only .060 inch in
diameter. The upper and lower regions 42, 44 of the
retainer riny 38 may thus cooperatively define a catch
50 for preventing the pliant guard 36 from slipping out
of the hearing aid 12 into the external region 24.
Moreover, the lower region 44 of the retainer ring 38
also includes an outer, tapered edge 52 that is tapered
away from the centerline 34 of the sound channel 23.
The tapered edge 52 acts as a gradual transition from
the central aperture to the external region 24.
In operation, the hearing aid 12 is inserted
into the canal of the userls ear with the hearing aid
port 20 pointing toward the ear drum. Sound is emitted
from the receiver 26 through the output port 32. The
sound passes through the sound channel 28 and through
the pliant guard 36 into the external region 24, which
includes the user's ear canal and ear drum.
Earwax may flow into the hearing aid port 20,
but is substantially prevented from entering the sound
channel 28 and output port 32 of the receiver 26 by the
pliant guard 36~ Instead, the pliant guard 36 collects
the wax.
After the pliant guard 36 has collected wax,
khe hearing aid 12 may be removed from the ear. An
implement, such as a simple tweezers (not ~hown), may
then be inserted into the hearing aid port 20 to grab
onto the pliant guard 36 and remove it. The soiled
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pliant guard 36 may then be disposed of and a fresh, new
pliant guard 36 may be inserted into the upper region 42
of the retainer ring 38. The heariny aid 12 is then
ready for continued use without fear that earwax will
enter the receiver 26 to clog or destroy it.
A preferred embodiment of the present
invention has been described herein. It is to be
understood, however, tha-t changes and modificatlons can
be made without departing from the true scope and spirit
of the present invention.
For example, the thickness and density of the
pliant guard 36 may be changed so that it will modify or
dampen, in a predetermined, desired manner, the sound
emitted from the hearing aid 12. In addition, the
preferred embodiment previously described shows the
shell 14 and retainer ring 38 as being separate
elements. Those of ordinary skill in the art will
quickly recognize, for example, -that the shell 14 and
retainer ring 38 could also be made as a single, uni~ary
cons~ruction. The true scope and spirit of the
invention are defined by the following claims and their
equivalents, to be interpreted in light of the foregoing
specification.
