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Description  |
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TECHNICAL FIELD
The invention relates to a protection element for the sound conduction
opening on an all-in-the-ear hearing aid.
BACKGROUND
The normal ear produces earwax which is conveyed outwards in the direction
of the outer auditory canal by a ciliary system. The presence of a hearing
aid in the outer ear can irritate the ear so that the production of wax
increases. In connection with the insertion of the hearing aid in the
auditory canal, it can happen that wax is pressed into the hearing aid's
sound conduction opening, and in certain cases completely into the sound
transducer, which is hereby ruined and must be changed. The sound
transducer can also be ruined in attempts to clean the sound conduction
opening. This phenomenon is a great problem for the propagation of this
otherwise very attractive type of hearing aid.
The problem of wax has hitherto been solved in many different ways. Some
solutions are based on a special shaping of the tip of the hearing aids,
whereby the wax collects in places where it causes no immediate damage and
is relatively easy to remove. Other solutions are based on replaceable or
cleanable devices called wax filters which intercept the wax.
With the known embodiments, the replacement of the wax filter is a
difficult operation. As example can be mentioned two
commercially-available systems. The one system has a circular filter cap
with internal thread and with a diameter of 3.7 mm and a height of 1.5 mm.
In the filter itself there are a number of small sound holes plus two
slightly larger holes. An accompanying tool for replacement is in the form
of a rod with two studs in the one end. These studs fit into the two
larger holes in the filter. When renewing the filter, the studs on the
replacement tool are engaged in the corresponding holes in the filter cap,
after which the filter cap can be screwed off. The used filter is removed
from the tool, and a new filter is mounted on the tool's studs, after
which it is screwed on to the hearing aid's threaded stub. Another known
system uses rectangular plastic filters which are pressed down in a stub
at the sound conduction opening of the hearing aid. These filters are
3.times.1.times.1.2 mm. The one side of the filter is provided with a
small hole of 1.times.0.5 mm, and along the edges of the filter there is a
collar which prevents the filter from being pressed too far into the
hearing aid. A bar-shaped tool has a small stud in the one end and a small
metal spade in the other end. The spade-shaped end is used to twist a
blocked filter out of the hearing aid, and the stud is used to hold a new
filter by means of the small hole in the filter edge while the filter is
mounted on the hearing aid and pressed into place.
From German presentation document no. 2,258,118 and from U.S. Pat. No.
3,414,685, protection elements for hearing aids of the kind mentioned are
known in the form of wax filters. In the patent documents, no guidance is
provided with regard to how the filters are exchanged, presumably because
this must always be carried out in a workshop for reasons of the filter's
very small dimensions.
From U.S. Pat. No. 4,444,677 is known a filter element which can be
introduced into the sound conduction opening on a hearing aid, and secured
by means of an elastic ear plug which surrounds and is snapped on to an
extension of the hearing aid housing itself. The patent document contains
no guidance in the exchanging of the filter.
As will be apparent, all of the known methods are characterized by parts
with very small dimensions, the handling of which places great demands on
both the eyesight and motory abilities. Moreover, the users of hearing
aids are frequently elderly people whose eyesight and powers of
manipulation do not allow them to handle such small parts. Therefore, the
users of hearing aids most often find it necessary to employ the services
of a special workshop in order to get a filter replaced.
The object of the invention is to present a protection element of the kind
mentioned which is very easy to mount on a hearing aid, and which provides
the user with the possibility of being able to renew the filter element
without having to resort to a specialist or another helper, if the user
has reduced eyesight or poor motory abilities, or is suffering from both
ailments.
This is achieved by designing the protection element in accordance with the
invention. The protection element consists of a sound conduction tube
which is firmly mounted in the hearing aid's sound conduction opening, and
a filter element arranged to be mounted on the sound conduction tube by a
snap connection between the filter element and the tube. The mounting is
effected simply by bringing the filter element and the hearing aid
together, preferably by pressing the hearing aid (which is much larger
than the filter) against the filter element. The snap connection is
designed in such a way that the filter element can be snapped both on and
off.
By configuring the protection element according to the invention, the
snapping action is effected in a manner which is perceptible, so that the
user is directly able to feel in the fingers when the filter element is
snapped correctly on the sound conduction tube, in that the snapping-on
takes place with a slight click which can be felt with the fingers.
By configuring the protection element according to the invention, one can
ensure that neither the filter element nor the sound conduction tube get
damaged, even though the mounting of the filter element is effected with a
relatively hard pressure. Moreover, the special configuration of the
filter edge and the sound conduction tube results in a free edge arising
on the filter element. This edge can serve as a surface of engagement for
a tool for the removal of the filter element. Furthermore, this
configuration results in the tool for the removal of the filter element
being able to be very simple in design, cf. the tool discussed later.
Moreover, this free edge with the engagement surface turns in towards the
hearing aid itself, and thus does not inconvenience the user in any way
whatsoever.
By configuring the protection element according to the invention a
relatively inexpensive and uncomplicated filter is achieved, said filter
having proved to function in an excellent manner and preventing any
ingress of earwax or dirt in the sound conduction opening, without any
blocking of the sound conduction opening acoustically. It is very
advantageous that the filter element can be produced for a low price,
hereby enabling the hearing aid users to change the filter element
frequently, so that a blockage capable of reducing the function of the
hearing aid is avoided. Moreover, the configuration results in the filter
element being slightly springy, which enables it to be designed with
relatively tight fitting against the sound conduction tube, without this
having any negative influence on the exchanging of the filter element. In
addition, the configuration enables the outer side, i.e. that side of the
filter element which faces in towards the user's ear drum, to be provided
with rounded and completely smooth surfaces, so that the filter element is
of no inconvenience whatsoever for the user.
By configuring the protection element according to the invention, the
necessity is avoided of having to make precise and accurate contact when
the hearing aid and the filter element are brought together during the
mounting of a new filter element, in that the parts are shaped in such a
way that they are guided into place for the snapping together, which is a
very great advantage when the users themselves need to mount a new filter
element on the hearing aid.
By configuring the protection element according to the invention , the
possibility is afforded of providing it with smaller diameters, i.e. the
whole construction can be of a slimmer form, and can thus be better used
by persons with narrow auditory channels.
The invention also relates to a tool for use in the removal of a filter
element from a hearing aid, in that said tool is arranged for use by the
users of the hearing aids themselves. The tool must be designed in such a
manner that there is no way in which it can be used incorrectly, and such
that it cannot damage the hearing aid in any way, regardless of how the
user applies the tool. This is achieved by designing the tool according to
the invention. The tool consists simply of a plate, preferably of plastic,
and with an opening of a certain clearance or diameter. The hearing aid is
brought with the sound conduction opening against the opening in the tool,
against which it is firmly pressed. The area on the tool is slightly
funnel-shaped towards the opening, so that the hearing aid's sound
conduction opening with the filter element is led towards said opening.
When the hearing aid is again drawn free of the opening, the filter
element is removed from the hearing aid. Also here the user will be able
to perceive a slight click, which indicates that the filter has been
removed. If one is in doubt, the operation may merely be repeated, in that
repeated attempts will damage neither the hearing aid nor the sound
conduction tube.
It can be an adavantage for the tool to be in the form of a dispenser. By
this is achieved that the filter sits firmly in the dispenser until it is
secured correctly on the sound conduction tube. When it is sitting
correctly and firmly on the sound conduction tube, and one thereafter
removes the hearing aid from the dispenser, the filter element is released
along the break-lines and the hearing aid is again ready for use.
Furthermore, in this way the tool is both a tool for the removal of the
used filters, and a tool for assisting in the mounting of new filters,
while at the same time it contains a closed chamber in which the used
filters are collected, thus preventing them from being inadvertently
reused, and avoiding inconveniences as a consequence hereof.
The tool according to the invention can be configured whereby one always
has a clear view of how many new filters are remaining in the dispenser,
in that this can be observed directly through the transparent cover. The
transparent, turnable cover has a delivery opening which can be turned to
stand over a new filter and help the user, so that he can more easily
guide the hearing aid down against the new filter when this is required to
be mounted. In this configuration, the tool itself can constitute sales
packing for new filters, thus rendering further packing unnecessary.
The invention will now be described in closer detail with reference to the
drawing, in that
FIG. 1 shows an all-in-the-ear hearing aid with protection element
according to a first embodiment of the invention,
FIG. 2 shows, on a larger scale and partly in plane section through the
sound conduction end, a mounted protection element according to the
invention,
FIG. 3 shows the filter element itself seen from the outer side,
FIG. 4 shows the filter element itself seen from the inner side,
FIG. 5 shows a dispenser with new filters,
FIG. 6 shows a plane section in the dispenser in FIG. 5, seen in the
direction VI--VI, and
FIG. 7 shows an all-in-the-ear hearing aid with protection element
according to a second embodiment of the invention.
In FIG. 1 of the drawing is seen a normal all-in-the-ear hearing aid 1
which comprises a housing of thermoplastic material which contains the
whole of the electronic circuit, sound receiver, sound transducer plus
battery and regulation elements. In the tip 2 of the housing there is a
sound conduction end with a protection element comprising a filter element
3, so that earwax cannot penetrate in through the sound conduction end,
which via a short sound channel leads to the sound transducer.
In FIG. 2 is seen a plane section on a larger scale through the sound
conduction channel 6 in the housing 2, the bottom of said channel 6 being
terminated with a sound conduction tube 5 of plastic or steel. In the tip
end of the hearing aid housing 2 can also be provided a ventilation
opening, as shown in the left side of FIG. 2.
The sound conduction tube 5 will normally be axis symmetrical, as shown in
FIG. 2, and be secured in the housing 2 of the hearing aid by means of
adhesive, crimping or by other means. The tube 5 has a free end 4 which
extends outside the housing, and the part which lies outside of the
housing is provided with a circular collar 7 which abuts against the outer
side of the housing 2. The free end 4 of the tube part is provided with a
projecting flange 8 with chamfered or rounded edges, as shown. The filter
element 3, which is in the form of a cap which can be snapped down over
the free end of the sound conduction tube, has a circular flange 13 around
its inside edge. For reasons of the resilient construction of the filter
element 3, said circular flange 13 can be snapped down over the projecting
flange 8 on the tube 5. The filter element 3 has an external diameter D
which is greater than the external diameter T of the sound conduction tube
5, so that there arises an annular, free and sharp edge 14 with an
engagement surface in which a tool for the removal of the filter element 3
can gain a hold.
In FIGS. 3 and 4 is seen the actual filter element 3, which is a one-piece
plastic part and comprises an annular and cylindrical part 9, a plane
masking part 10 and a number of bridge parts 11 between said two parts.
There thus arises a number of sound conduction openings 12, partly
concealed by the masking part 10 which covers the openings 12 so that wax
and the like cannot directly penetrate through the openings and into the
sound conduction tube 5, and thereby into the sound conduction channel 6.
In FIGS. 5 and 6 of the drawing is seen a tool designed as a dispenser 22
and for use in the replacement of filter elements 3 according to the
invention. The dispenser consists of three parts 15,16,17, all of which
are preferably of plastic. The part 15, which constitutues a support part
for the remaining parts, also comprises a number of moulded filter
elements 3 which are moulded in one with the support part 15, and which at
the bridge-like deadheads 18 are firmly connected to the support part 15.
The deadheads 18 narrow down towards the filter elements, so that said
elements can be broken free of the deadheads in such a manner that the
deadheads remain sitting firmly on the part 15. Below the filter elements,
which in the example shown are disposed in a ring in the dispenser, is
provided a bottomplate 16 which serves as underlayer and support when a
filter is being mounted by the hearing aid's sound conduction tube being
pressed down into the filter element. In addition, the dispenser comprises
a transparent cover 17 with an opening 25. This opening 25 can be turned
into place over an unused filter when the filter is to be secured to a
hearing aid. A central part 24 of the support part 15 is formed as a
chamber 21 which is closed by the bottomplate 16. The chamber has a
centrally disposed opening 20 with a clearance or diameter d which is
smaller than the outer diameter D of the filter element. Preferably, d is
equal to t, see FIG. 2. The chamber 21 is intended for the collection of
used filter elements. 19 indicates an empty place from which the filter
element has been removed. The central part 24 will preferably be of a
slight funnel shape in towards the central opening 20.
When a hearing aid 1 with filter element 3 is pressed down against the
opening 20, the filter element 3 will be able to be fed in through the
opening 20 and into the chamber 21 with a slight click. When the hearing
aid is removed again, the edge 14 of the filter element will abut against
the under edge of the opening 20, and the filter element will be removed
and remain in the chamber 21.
It will be obvious to those skilled in the art that the configuration of
the sound conduction tube 5 and the filter element 3 shown in the drawing
is only an example of how these can be configured. Said parts can be
designed in many other ways without deviating from basic concept of the
invention. FIG. 7 of the drawing shows an example of an embodiment in
which the filter element 3' is snapped firmly inside the sound conduction
tube 5'. The same reference figures have been used for all parts as in
FIG. 2, and those parts which are configured differently are indicated
with the FIGS. 3', 5', 8' and 13'. The inside of the sound tube 5' has a
recess which prevents the filter element 3' from being pressed too far
inside the tube. The filter element 3' has an annular bottom part 23 which
goes over to a tubular part 24 which is arranged for insertion into the
sound conduction tube, said tube having an internal annual groove for the
flange 13' on the filter unit 3'. This filter unit 3' is mounted and
removed in the same manner as described earlier in connection with the
first embodiment.
Similarly, the dispenser shown in FIGS. 5 and 6 is solely an example of how
such a tool can be arranged for use in the exchanging of filter elements.
In the examples shown in the drawing, the filter element is of the
following dimensions: D=4.2 mm and the greatest height of the filter
element is 1.45 mm. The sound conduction tube has an axial length of 2.65
mm and t=3.9 mm.
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