Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02649594 2009-01-13
DEVICE FOR CLEANING TEETH
This application is a division of Canadian Patent Serial
No. 2,439,560 filed on March 14, 2001.
This invention relates to an electric dental cleaning
device. The invention relates in particular to the handle
section of such a dental cleaning device which has at least
one or several coupling sections for the coupling of various
cleaning tools, a drive mechanism for driving the coupled
cleaning tool, and a control device. Finally the invention
relates to the cleaning tools, particularly brush attachments
for such a handle section.
Dental cleaning devices such as electric toothbrushes or
electric oral irrigators customarily have a grip or a handle
section or handhold to which a variety of cleaning tools such
as brush attachments, jet nozzles, interproximal brushes are
attachable, thus enabling several users to use the dental
cleaning device with their own, in particular person-related
cleaning tools. Such electric toothbrushes are known, for
example, from DE 19627752 Al or EP 0624079 B1.
From DE 299 15 858 Ul a dental cleaning device is known
in which each of the different toothbrushes can be inserted
only into its assigned receptacle in a console. This then
starts the program provided for this particular toothbrush.
Particularly children find it however difficult to locate the
individual opening for insertion of their personal toothbrush
and to mate the plug there. Furthermore, this console in-
volves high complexity of manufacture, considering that it
requires the provision of a plurality of different
receptacles and each of the toothbrushes has a different plug
assigned to its own receptacle.
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In a further device disclosed in U.S. Pat. No.
5,184,959, each hand toothbrush is assigned its own accommo-
dating slot in a housing, so that each toothbrush can be
assigned an individual brushing time signal via the housing.
This arrangement is very elaborate from the manufacturing
point of view without providing for the detection and storage
of user-specific data of the tooth cleaning operation.
Such dental cleaning devices are capable of improvement
on many counts. One problem is in particular that in
storage-battery-operated toothbrushes the storage battery may
become depleted prematurely. This may happen, for example,
in cases where the toothbrush is not properly stowed away in
a travel bag or the like, so that the drive mechanism turns
on accidentally. Furthermore, it may happen that the handle
section is not always coupled with the correct brush attach-
ments, so that as a result of the lack of compatibility the
handle section, for example, the coupling sections, may be
damaged particularly in the area of the drive train, or a
proper cleaning function is not assured, likewise for lack of
compatibility.
It is therefore an object of the present invention to
provide an improved handle section of an electric dental
cleaning device and improved cleaning tools therefor, which
avoid the disadvantages of the prior art, develop it further
and afford additional advantages. In particular the inven-
tion aims to provide a comfortable safety device preventing
accidental activation and/or improper use of the dental
cleaning device.
According to the invention the object referred to in the
foregoing is accomplished in a handle section of an electric
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dental cleaning device of the type initially referred to
essentially in that a control device of the handle section
possesses an interlock device which can be deactivated by an
interlock canceling element provided on the cleaning tool.
With regard to the cleaning tool of the type initially re-
ferred to, this object is accomplished in that it possesses
an interlock canceling element for deactivating the interlock
device of the handle section. Preferred embodiments of the
invention are the subject-matter of dependent claims.
These solutions hence afford protection against acciden-
tal activation of the dental cleaning device. The drive
mechanism of the handle section can be turned on only when a
compatible cleaning tool is attached to the handle section,
whereupon the interlock device is deactivated. Accidental
turning on in the travel case can be prevented simply by de-
taching the cleaning tool from the handle section. Any inad-
vertent premature discharge of a storage battery is not
possible either. Additional provisions in terms of the
design or mechanics for implementation of the interlock, for
example, on the switch of the handle section, are unneces-
sary.
In a further aspect of the invention provision may be
made for the interlock device to be deactivatable exclusively
by the interlock canceling element of the cleaning tool, in
particular only when the cleaning tool is properly coupled to
the handle section. This is accomplishable in that the in-
terlock canceling element provided on the cleaning tool and a
detection device provided on the handle section for detecting
the presence of the interlock canceling element are con-
structed and in relative agreement in such manner that the
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interlock canceling element is effective preferably in a pre-
determined orientation and/or position relative to the detec-
tion device and hence to the handle section.
To prevent the handle section, in particular the drive
train or its coupling device from being damaged by the
attachment of incompatible brush attachments, the interlock
canceling element may be configured as an encoding identify-
ing the cleaning tool. The handle section then includes an
encoding detection device detecting the encoding of the
attached cleaning tool. The interlock device is deactivated
only when the encoding detection device reads the proper en-
coding and generates a corresponding signal. Hence the
handle section detects the cleaning tool attached thereto and
controls, in response to the detected cleaning tool, the re-
lease of the drive mechanism.
It will be understood that the encoding detection device
may sample an encoding of the cleaning tool at predetermined
intervals. In a particular configuration of the invention
the encoding detection device is activated only when an on-
switch of the handle section, for example, of the electric
drive mechanism, is actuated. This has the advantage that
the current consumption of the encoding detection device is
kept at a minimum level. To turn the dental cleaning device
on, the user actuates the on-off switch of the control device
or of the electric motor as usual. Actuation of the switch,
however, does not set the electric motor, meaning the drive
mechanism, in operation directly, but initially activates
only the encoding detection device which, upon establishing
that a compatible brush attachment, i.e., a brush attachment
with the proper encoding, is coupled to the handle section,
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then sets the motor of the handle section in operation.
Ultimately, therefore, an activation of the encoding detec-
tion device by means of the on-off switch sets the drive
mechanism of the handle section in operation only indirectly,
that is, when the interlock canceling element of the brush
section deactivates the interlock device of the handle sec-
tion. In the absence of a brush section attached or coupled
to the handle section or in the event of an incompatible
brush section fitted to the handle section, the encoding de-
tection device, upon actuation of the on-off switch, will
fail to detect a proper encoding, or the absence of the in-
terlock canceling element on the brush attachment will pre-
vent the interlock device on the handle section from being
deactivated, so that in this case the handle section of the
electric-motor-operated toothbrush cannot be set in opera-
tion. Among other advantages, this approach involving acti-
vation of the encoding detection device by means of the on-
off switch has the advantage that power supply to the encod-
ing detection device is necessary preferably only during
operation of the on-off switch of the handle section, while
being otherwise inactive or passive. It will be understood,
of course, that it is also possible for the encoding detec-
tion device to be activated at regular or irregular intervals
during operation of the toothbrush in order to check the
presence of a compatible, that is, properly encoded brush
attachment also during periods other than the on-off switch-
ing period. When the on-off switch is actuated again on
termination of the dental cleaning operation to turn off the
drive of the handle section, this will stop the drive
promptly and, where provided, will deactivate the interlock
device, so that when the on-off switch on the handle section
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is switched on again subsequently the described cycle can be
repeated.
A variety of approaches are possible for detection of
the encoding provided directly on the cleaning tools or the
signals of the interlock canceling element and for the encod-
ing or configuration of the interlock canceling element of
the cleaning tools.
In particularly simple manner the cleaning tool is en-
coded by its shape. It may possess one or several shaped
bodies which are connected to the body of the cleaning tool
in particular fixedly and lie in the range of detection of
the encoding detection device of the handle section when the
cleaning tool is coupled to the handle section. The encoding
may embody a specific geometrical contour, for example, outer
contour, and/or a specific spatial arrangement of the shaped
body relative to the coupling section of the cleaning tool
and hence also to the encoding detection device on the handle
section. Detection of the shaped body or bodies may be per-
formed in noncontacting fashion using, for example, light
barriers or the like.
In an embodiment of the invention the encoding of the
individual cleaning tool is brought into mechanical contact
with the encoding detection device, enabling it to read the
encoding. This results in a particularly straightforward
construction.
The handle section may include a scanning device for
scanning the encoding provided on the respective cleaning
tool being used, that is, for deactivating the interlock.
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Preferably the handle section may include a movable or
deformable sensing element which is moved, deformed or other-
wise acted upon by the mechanical encoding of the cleaning
tool as the latter is being seated onto the handle section.
Depending on the encoding, the sensing element is moved or
displaced or deformed by a predetermined amount or in a pre-
determined direction. The sensing element produces a signal
responsive to the movement or deformation so that the encod-
ing can be detected. The sensing element may also be config-
ured in such manner that it senses a force or a field, for
example, an electromagnetic field, which is generated by the
encoding and acts upon the sensing element as the cleaning
tool is being seated onto the handle section, causing the
sensing element to deliver actively a signal. To obtain a
particularly simple configuration the sensing element may be
constructed as a preferably electromechanical contact member.
This member, upon being correspondingly deformed or moved by
the encoding of the cleaning tool, then opens or preferably
closes one or several contacts so that a corresponding signal
is produced.
The sensing element may be configured in such a manner
that it is deformed to different degrees or moved in differ-
ent directions responsive to the encoding of the attached
cleaning tool, correspondingly closing different contacts or
a different number of contacts.
In a further aspect of the invention provision is made
for several sensing elements so that different encodings of
the cleaning tools cause different sensing elements or a
different number of sensing elements to be actuated.
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The sensing element(s) may be arranged so as to be
freely accessible. In this arrangement the sensing element
may be brought into operative association directly with a
corresponding encoding element of the cleaning tool. In an
advantageous embodiment of the invention the sensing element
is indirectly actuatable. The sensing element may be dis-
posed in the interior of a housing of the handle section
which may have a deformable portion, for example in the form
of a soft plastic portion, through which the sensing element
can be actuated. This enables a sealed, in particular fluid-
tight construction of the handle section to be obtained.
In another advantageous embodiment of the invention the
encoding detection device may include a movable probe element
which is moved by the encoding of the cleaning tool during
its seating engagement with the handle section. The encoding
detection device includes a motion sensor detecting the move-
ment or displacement of the probe element advantageously in
terms of amount and/or magnitude. The encoding of different
cleaning tools may be uniform or, alternatively, different so
as to effect movements or displacements of the probe element
of different magnitude and/or in different directions as the
cleaning tool is being attached to the handle section. Pro-
vision may be made for several probe elements so that indi-
vidual probe elements or different combinations of probe ele-
ments can be actuated by differently arranged encoding
sections of the cleaning tools.
Various configurations are possible for the
motion/displacement sensor. It may operate optically, for
example, in the manner of a light barrier. It may also de-
tect the force exerted on the probe element by an encoding.
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Preferably a sensing element of the type described in the
foregoing may find application which in this case is actuated
indirectly, that is, through the probe element.
A particularly advantageous embodiment of the invention
resides in that the probe element is the drive shaft of the
drive mechanism arranged in the handle section for driving
the cleaning tool. The drive shaft may be mounted in the
handle section in longitudinally displaceable fashion so that
it is pushed into the interior of the handle section a cer-
tain amount by the encoding of the cleaning tool as it is
being seated onto the handle section. The use of the drive
shaft as probe element obviates the need for any specific
additional arrangements with regard to the sealing of the
handle section because the drive shaft is invariably sealed.
In this embodiment it proves however necessary for the
attachment, in particular the brush attachment, to be held on
the handle section in a defined end position when in coupled
condition. This is accomplishable, for example, by providing
in or on the coupling shank of the handle section detent
elements such as grooves, projections or the like which coop-
erate with corresponding mating detent elements as, for
example, the tube of the attached cleaning tool and ensure,
by such cooperation, that the brush attachment can be coupled
to the handle section only in an accurately defined position.
This position is selected such that when an attachment is in
this defined coupling position the drive shaft is displaced
axially toward the handle section by a predetermined amount,
this displacement being used, for example, to actuate a
switch or the like. The prerequisite for this is, of course,
that the attachment includes elements registering with the
drive shaft or the shaft's free end, as, for example,
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abutments, bearing surfaces, activating elements, which on
seating of the brush attachment onto the handle section and
bringing it into the defined end position produce a defined
axial displacement of the drive shaft so that this displace-
ment of the drive shaft enables the actuation of associated
switches or other sensors arranged in the interior of the
handle section, this arrangement being hence likewise suit-
able for detecting the presence of a coupled brush attachment
on the handle section provided that the brush attachment is a
compatible replacement brush or some other replacement clean-
ing tool suited or permitted for use with the handle section.
As encoding the cleaning tool preferably has an actuat-
ing surface, in particular a pressure application surface, an
abutment or some other activating element which is con-
structed and arranged such as to make engagement or contact
with an engagement surface of the encoding detection device
when the cleaning tool is seated onto the handle section,
exerting a defined effect on said surface. The actuating
surface and the engagement surface thus form interacting sur-
faces. Provision may be made for actuating surfaces of
different encoding to exert different effects on the same
engagement surface, moving it, for example, a greater or
lesser amount. Provision may further be made for different
actuating surfaces to act on different engagement surfaces,
thereby enabling the encoding to be read. The engagement
surface on the handle section may be disposed directly on the
sensing element previously described or, alternatively, on
the probe element likewise described in the foregoing, in
particular on the drive shaft of the handle section. In the
last mentioned instance the actuating surface is preferably
provided on a drive shaft section of the drive shaft provided
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in the cleaning tool. This arrangement is particularly ad-
vantageous because it makes use of the existing coupling
sections provided for the coupling of cleaning tool and
handle section, which coupling sections, suitably modified,
detect the respective cleaning tool, thus obviating the need
to provide additional mechanical elements for this purpose.
The coupling section on the cleaning tool is suitably encoded
by means and in the form of an actuating surface to exert a
defined effect, particularly a defined actuating motion, for
example, a defined stroke, on the coupling section on the
handle section which for this purpose is provided with a
corresponding engagement surface.
In another advantageous embodiment of the invention the
encoding detection device is of the noncontacting type. This
has the advantage of avoiding malfunctions due to contami-
nated contact surfaces or wear resulting from frequent
attachment and disengagement operations.
According to a further aspect of the invention the
handle section may include a signal receiver for receiving
from the cleaning tool an encoded signal or an interlock de-
activating signal. The handle section may also possess a
signal transmitter emitting an interrogation or activation
signal to the cleaning tool which responds by sending the en-
coded signal or the interlock deactivating signal back. The
emission of the encoded signal or interlock deactivating sig-
nal by the cleaning tool may take place actively by a corre-
sponding signal transmitter or a suitable acting member, as a
magnet or the like. The possibility also exists for passive
reflection to take place on the cleaning tool, which produces
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a corresponding encoding of the signal or an interlock
deactivating signal.
The encoding or configuration of the interlock canceling
element of the cleaning tools and the corresponding detection of
the encoding or interlock canceling element may be implemented
in a further variety of ways. According to a preferred
embodiment of the invention provision is made for a magnetic
sensor detecting a magnetic encoding or a magnetically effective
interlock canceling element of the respective cleaning tool
attached to the handle section. The magnetic encoding or
configuration of the interlock canceling element of the cleaning
tool(s) may take place by introducing a uniform or, where
provided, individually different number of magnetic particles or
a preferably small magnetic, for example, a bar magnet or some
other permanent magnet into the cleaning tool itself or in a
portion or part of the cleaning tool, for example, in a colored
ring or profiled ring as represented, for example in WO
99/20202. The sensor for detecting the magnet, meaning the
magnetic field, of the cleaning tool may also be of different
configurations. According to a preferred embodiment of the
invention the handle section includes, preferably in the upper
section of the area of coupling with the attachable cleaning
tool, a Hall sensor providing an electrical signal corresponding
to the magnetic encoding or to the one uniform magnet of the
interlock canceling element of the respective cleaning tool.
According to a further preferred embodiment of the invention the
handle section may include an LC oscillator which is detuned by
the magnetic encoding or the magnet of the attached cleaning
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tool, thus supplying different frequencies assignable to the
individual users for purposes of deactivating the interlock
of the handle section.
Another advantageous embodiment of the invention resides
in the provision of one or several reed contacts on the
handle section which are actuated in particular individually
when the cleaning tools are attached to the handle section.
Depending on the combination of contacts actuated, an inter-
lock deactivating signal may be generated or not. In accor-
dance with an advantageous embodiment of the invention provi-
sion may be made for an optical sensor for detecting an
optical encoding of the respective cleaning tool attached to
the handle section. As optical encoding a color code may be
provided on the cleaning tool which is identified by a color
sensor.
Advantageously the handle section may also be equipped
with one or several optical waveguides exiting from the
handle section and emitting an optical signal. The light
signal delivered to the cleaning tool is encoded by the tool
and returned to the handle section which receives this en-
coded signal by means of a corresponding sensor or detector
and converts it, receiving it by means of corresponding opti-
cal waveguides and transmitting it to a corresponding sensor.
The encoding may take place by defined interruption or par-
tial obstruction of the optical waveguides exiting from the
handle section. Moreover, the light exiting from the handle
section through the optical waveguide can be reflected dif-
ferently by the toothbrush. The interlock device can be
deactivated in response to the intensity of reflection.
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According to another preferred embodiment of the inven-
tion provision may be made for a capacitive sensor for
detecting a capacitive encoding, meaning the presence of the
interlock canceling element of the respective cleaning tool
attached. In particular the handle section may have two or
more capacitor plates whose capacitance is varied by the in-
troduction of a dielectric provided on the cleaning tool.
The encoding of the cleaning tools may be performed by
different dielectric portions on the respective cleaning
tool. A particular or compatible cleaning tool is then de-
tectable in accordance with the variation in capacitance.
In a further advantageous embodiment of the detection
device provision is made for an electrically operating sensor
for detecting an electrical encoding, meaning the presence of
the interlock canceling element of the respective cleaning
tool attached. The cleaning tool sends an encoded electrical
signal to the handle section, meaning to a signal receiver
provided thereon, thus enabling the respective cleaning tool
to be identified. It is also possible for the handle section
to send initially an interrogation signal to the cleaning
tool which is encoded by the cleaning tool and subsequently
sent back.
In a further aspect of the invention provision may be
made for a transmit or radio device for detecting the respec-
tive cleaning tool attached by means of electromagnetic
waves. In particular a transponder may be associated with
the cleaning tool. The handle section initially emits elec-
tromagnetic waves for energy supply to the transponder. The
transponder stores the energy and sends an individual identi-
fication back to a detector in the handle section which
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detects it and correspondingly identifies the cleaning tool
and deactivates the interlock.
The characteristic features of the cleaning tool thus
include a magnetic, electrical, optical, capacitive, electro-
magnetic and/or mechanical encoding device or such an inter-
lock canceling element. Another characteristic feature may
include a signal receiver for receiving a signal from the
dental cleaning device and a signal transmitter for transmit-
ting an encoded signal to the dental cleaning device, with an
encoding device being inserted between the signal receiver
and the signal transmitter for encoding the received signal.
The encoding device or interlock canceling element is
preferably constructed as a separate component suitable for
detachment from the remaining part of the cleaning tool or
for replacement. This affords the advantage of requiring
only a single mold for the manufacture of the cleaning tool.
By mounting the separate encoding device the cleaning tools
are encoded on an individual basis and assignable to a handle
section of a particular type. However, the encoding device
constructed as interlock canceling element may also be inte-
grated in the cleaning tool when it is desirable to implement
merely the function of a safety interlock preventing switch-
ing on of the appliance on travels or in combination with
incompatible cleaning tools.
The encoding device is arranged preferably in the area
of the connection or coupling between the cleaning tool and
the handle section. This facilitates the reading of the en-
coding, meaning the detection of the interlock canceling
element by the recognition device on the handle section. In
particular the encoding device may be integrated in a ring
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arranged at the end of the cleaning tool close to the handle
section, being in particular snap-fittable thereto by posi-
tive engagement therewith. The various configurations of the
recognition devices may be provided singularly or in combina-
tion. The same applies to the various configurations of the
encoding device on the cleaning tool.
Apart from protecting the handle section against inad-
vertent turning on and improper use of incompatible cleaning
tools, an encoding of the cleaning tools and its detection by
the handle section may be utilized to advantage for imple-
menting further functions. In a further aspect of the inven-
tion the handle section may control one or preferably several
functions of the dental cleaning device in dependence upon
the respective cleaning tool detected. Assuming that each
user of the handle section has his or her own cleaning tool,
particularly the control device of the handle section may
establish automatically, by referring to the detected encod-
ing on the cleaning tool, which user is currently using the
dental cleaning device. There is no need on the user's part
to inform the dental cleaning device of its current user as
by pressing a button and the like. An adaptation to the in-
dividual user can take place automatically. This results in
a maximum of user friendliness.
In particular in a further feature of the invention the
control device is capable of adapting operating parameters
such as brushing frequency, brushing speed and brushing time
or threshold value or desired range of application pressure
automatically to the individual user identified. A variety
of user profiles can be set and stored, one of which is used
by the control device after, at the beginning of brushing,
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the encoding of the cleaning tool being used has been de-
tected and the respective user has been established. To this
effect the encoding detection device has issued a correspond-
ing signal to the control device. Where electric tooth-
brushes are used, it is possible for example for the motor
speed to be reduced from the usual speed for adults when a
child is the user, so that a gentler cleaning operation is
performed for the child. In addition, the control device may
vary, responsive to a signal from the encoding detection
device, the duration of a timer according to the user identi-
fied, setting the timer to two minutes for children and to
three minutes for adults, for example. The type of timer
signal could also be modified, as by selecting a tune for
children and a buzzer tone for adults.
In a further aspect of the invention it is also
possible to store, process and indicate as on a display user-
specific data such as brushing frequency, brushing speed,
brushing time, time interval between brushing operations or
application pressure automatically in response to a corre-
sponding signal from the detection device. This too results
in enhanced user comfort.
The handle section then detects, i.e., identifies, the
individual user indirectly by referring to the cleaning tool
used or its encoding. Each user is assigned to a cleaning
tool of his or her own. For this purpose the cleaning tools,
which otherwise may be of identical construction, may have
user-specific encoding elements.
Provision may also be made for a specific function con-
trol in dependence upon the particular type of cleaning tool
used. For instance, operating parameters of the handle
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section may be varied automatically when a brush attachment
with specific properties such as high or low hardness is
used. Equally, an other operating program may be run when a
cleaning tool of different type as, for example, an inter-
proximal cleaning tool, a tool for gum massage or a tongue
scraper is attached to the handle section. Rotational speed,
desired cleaning time, driving motion, cleaning frequency,
cleaning speed, application pressure threshold value, etc.
can be suitably adapted in response to the individual and/or
person-related exchangeable cleaning tool.
Still further, by identifying an individual cleaning or
brushing tool or refill unmistakably it is possible to estab-
lish its state of wear precisely, for example, by evaluating
the history of this particular cleaning tool, in particular
the time of past uses. Where cleaning tools with chemical
additives are used, their ,use by" date can be identified by
the date of manufacture hidden in the encoding. Predeter-
mined cleaning or maintenance intervals can be indicated.
In summary, the gist of the present invention shall be
presented as follows, also independently of the wording in
the claims: The interlock canceling element on the cleaning
tool for deactivation of the interlock device can be config-
ured in the simplest configuration of the encoding detection
device in such manner that only the presence or absence of a
replacement brush on the handle section is detectable. To
this effect, for example, an acting member may be arranged in
the brush which corresponds with a reacting member disposed
in the handle section in such manner that with the cleaning
tool and the handle section in coupled condition the reacting
member receives from the acting member a signal and
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deactivates, for example, the interlock device, thus enabling
the handle section and hence also the cleaning tool to be set
in operation by means of the drive mechanism. This provides
a simple design of a travel safety device for the handle sec-
tion preventing the handle section from operating when the
cleaning tool with its acting member is not coupled thereto
as described above. Accordingly it is sufficient to decouple
the cleaning tool from the handle section to activate the
travel interlock. Further steps for locking, for example,
the on-off switch of the handle section or any other devices
are not necessary. It is also helpful to arrange such an
acting member in the cleaning tool which in coupled condition
corresponds or communicates with a reacting member in the
handle section so that operation of the handle section with
incompatible cleaning tools can be prevented, because the
manufacturer does not equip such incompatible cleaning tools
with an acting member capable of communicating with the re-
acting member of the handle section. This represents an
encoding detection device in its simplest form, it is of
relatively straightforward construction and permits merely a
decision to be made as to whether a cleaning tool is coupled
to the handle section or whether a compatible cleaning tool
is coupled to the handle section.
For exceptional situations provision may also be made
for the acting member typically provided in the cleaning
tool, for example, a magnet or the like or the encoding
device to be made available to the end user as a separately
handleable isolated part or to provide it on the handle sec-
tion itself. This approach offers itself, for example, when
the end user is already in possession of a handle section
equipped with an interlock device but has a household supply
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of brushing or cleaning tools available which are not
equipped with an interlock canceling element or an acting
member for deactivation of the interlock of the handle sec-
tion or handhold. To assure usability of these typically
older replacement cleaning tools which, while being mechani-
cally compatible with the more recent handhold, do not have
as yet an interlock canceling element which would be suited
for communication with, and deactivation of, the interlock
device provided in the handle section, a meaningful approach
may therefore be to make the interlock canceling element or
the acting member available to the end user as a separately
handleable component, providing for these exceptional situa-
tions a fastening device on the handle section to fasten the
interlock canceling element there. This enables, for
example, the end user to fasten this interlock canceling
element or acting member directly to the handle section or
handhold equipped with the interlock device, as on the ex-
terior of the housing in the area of the reacting member of
the handle section, and to deactivate for such special or
exceptional cases the interlock device on the handle section
by arranging the acting member on the handle section itself
and not on the cleaning tool. As a result, the handle sec-
tion is also operable with cleaning tools which, while being
mechanically compatible, are not as yet equipped with an in-
terlock canceling element or an acting member communicating
with the interlock device. This solution may also be contem-
plated when for cost reasons, for example, not all of the re-
placement cleaning tools compatible or mechanically mating
with the handle section or handhold are equipped with such an
interlock canceling element, an encoding device or an acting
member. It will be understood, of course, that the solution
involving the fastening of the interlock canceling element
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directly to the handle section as by its user is an excep-
tional situation, and that as a rule the interlock canceling
element should be arranged on the brush section or cleaning
section. Particularly in the event of the interlock cancel-
ing element being a magnetic field effecting member having
associated with it a reacting member in the handle section or
handhold which is responsive to magnetic fields, a solution
offering itself for this exceptional case may involve mag-
netization of the handle section's drive shaft, which is
typically disposed in close proximity to the reacting member,
for deactivation of the interlock device of the handle sec-
tion, or to provide a magnetic adhesive strip or the like
which may be adhered to the handle section at a suitable lo-
cation in the area of the reacting member. This approach,
too, enables deactivation of the interlock device and opera-
tion of the handle section or handhold with compatible clean-
ing tools having no interlock canceling element.
Still further, the encoding detection device may also be
configured so as to enable the coupling of a cleaning tool
allowing for a few possibilities of distinction of cleaning
tools. While the encoding detection device initially de-
scribed permits, for example, only a yes/no decision, that
is, a decision as to whether or not a compatible cleaning
tool is coupled to the handle section, a modified encoding
detection device permitting, for example, the identification
of two, four or six different encodings of the cleaning tool
enables further functions to be implemented in addition to
the travel safety function. Thus, for example, it is
possible for the handle section to identify whether a
toothbrush designed for adults (hard bristles) or a tooth-
brush designed for children (soft bristles) is coupled to the
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handle section, whether an interproximal cleaning device is
used in lieu of a toothbrush, or also to distinguish between
other parameters. Where provided, the detected encoding can
be used for an individual actuation of the control device for
the drive including, for example, a control of the speed of
the drive as the rotational speed or the desired brushing
time or the like. In the event of provision being made for
an encoding or an encoding detection device with few (between
about two and about ten) possibilities of distinction, it is
however not possible as yet to identify an individual clean-
ing tool from a million of commercially available cleaning
tools. With these limited possibilities of distinction it is
at best possible to identify a special type of cleaning tool
(child toothbrush, adult toothbrush, interproximal brush,
dental flossing device, each configured as an attachment to
the handle section) and to make a distinction between a few
person-related cleaning or brushing tools.
When it is desired to detect with the encoding detection
device every single individual cleaning tool produced by the
manufacturer which is adapted to be coupled to the handle
section as a compatible part, allowance need be made for a
multiplicity of possibilities of distinction in the range
from about l06 to about 1012, for which purpose a transponder
or similar electronic device is typically used. In this case
identification of an individual cleaning tool supplied by the
manufacturer and coupled to the handle section is possible.
In addition to the possibilities already mentioned in connec-
tion with simpler encodings, this provides the prerequisite
for the ability to determine, for example, the degree of wear
of the cleaning tool more accurately by evaluating the tool
history. Where replacement cleaning tools with chemical
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additives are used, the date of manufacture indicated in the
encoding enables ,use by" dates to be identified or predeter-
mined cleaning or maintenance intervals of the cleaning tool
to be indicated or complied with.
Regardless of how simple or complicated the encoding of
the cleaning tool and the encoding detection device, each of
these encodings is suitable for providing a travel safety
function by decoupling the in particular compatible cleaning
tool from the handle section, thereby preventing operation of
the handle section. Setting the handle section in operation
is likewise prevented with any one of these encodings,
whether of simple or elaborate design, if the cleaning tool
does not have an encoding or interlock canceling element in
the first place. When such a cleaning tool which is not en-
coded or not equipped with an interlock canceling element is
coupled to the handle section, the reacting member, transmit-
ter, receiver or similar device positioned in the handle sec-
tion is unable to communicate with the acting member, trans-
mitter, receiver, transponder or similar device not provided
in the incompatible cleaning tool, so that precisely as in
the case of a cleaning tool which is compatible but not
coupled to the handle section, the presence of this incom-
patible cleaning tool is not recognized on the handle
section, as a result of which the handle section cannot be
set in operation due to the absence of the interlock cancel-
ing element and the attendant lack of possible deactivation
of the interlock device.
In the basically most straightforward form of construc-
tion of the encoding of the cleaning tool or the encoding
detection device in the handle section of the electric tooth-
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CA 02649594 2009-01-13
brushing device, care has to be taken only to ensure that the
encoding detection device in the handle section is in a posi-
tion to recognize whether or not a proper, i.e., compatible
cleaning tool is coupled to the handle section. If such a
proper, i.e., compatible cleaning tool is not coupled to the
handle section, the handle section cannot be set in opera-
tion, because the cleaning tool has no associated interlock
canceling element suitable for deactivation of an interlock
device provided in the handle section. By contrast, when a
compatible cleaning tool equipped with the interlock cancel-
ing element or the proper encoding is coupled to the handle
section, it is not later than on actuation of the on-off
switch on the handle section that the presence of the proper
encoding or interlock canceling element will be detected by
means of a detection device in the handle section, causing
deactivation of the interlock device and setting the handle
section in operation, so that the cleaning end, for example,
the brush head of the cleaning tool, is set in operation by
the drive mechanism of the handle section.
Insofar, the present invention also relates to a method
of operating an electric tooth cleaning or tooth brushing
device comprised of a handle section and a cleaning tool
adapted to be attached or coupled thereto, as for example, a
brush attachment or the like, wherein the handle section and
the cleaning tool communicate with each other in coupled con-
dition, devices being provided in the handle section which
are in a position to detect whether a cleaning tool is
coupled to the handle section and/or whether the cleaning
tool coupled to the handle section is a cleaning tool com-
patible with the handle section. When no cleaning tool is
coupled to the handle section, this information is used for
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CA 02649594 2009-01-13
suppressing an activation of the electric drive of the handle
section, which could take place, for example, by means of the
on-switch provided on the handle section. This may be accom-
plished, for example, by an interlock device in the handle
section. Hence it is not possible to set the handle section
in operation with the cleaning tool not coupled or attached
thereto, whereby a comfortable travel safety device is ob-
tained. A further feature characteristic of the method is
that the cleaning tool includes an interlock canceling ele-
ment signaling to a detection device arranged in the handle
section that the cleaning tool is coupled to the handle sec-
tion and the interlock device can be deactivated, meaning
canceled, to enable the dental cleaning appliance to be set
in operation by turning on the electric drive. If however
the cleaning tool is not equipped with such an interlock can-
celing element, even in coupled condition of cleaning tool
and handle section the drive of the handle section cannot be
activated because in the absence of an interlock canceling
element on the cleaning tool it has to be assumed that a
cleaning tool incompatible with the handle section is in-
volved.
Further embodiments of the method also include the step
of encoding the different cleaning tools to be coupled to the
handle section on a person-related, cleaning-tool-related or
similar basis, enabling the handle section or handhold to be
informed, via a corresponding encoding detection device, not
only of the coupled or non-coupled condition of a cleaning
tool or a compatible cleaning tool but also of the type of
cleaning tool used or the individual using the cleaning tool,
so that corresponding parameters or also operating parameters
of the handle section can be set or stored as person- and/or
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cleaning-tool-related data. These individual approaches are
explained in detail within the scope of the description of the
device and also pertain to the present method as features
essential to the present invention. It will be understood that
within the scope of the present invention the terms interlock
device and encoding detection device or recognition device as
well as the terms interlock canceling element and encoding device
or encoding element are used as synonyms and may be used
interchangeably in each individual case without departing from
the scope of the invention.
In summary of the foregoing, there is provided in one aspect
of the invention a handle section of an electric dental cleaning
device that is capable of use with a cleaning tool that includes
a first coil configured to receive and transmit electromagnetic
waves, the handle section comprising a handle housing; a coupling
section at an end of the handle housing for coupling the cleaning
tool thereto; a detector and a second coil configured to transmit
and receive electromagnetic waves to and from first coil in the
cleaning tool; a drive mechanism for driving the cleaning tool
coupled to the coupling section; and a control device located in
or on the handle housing that controls the drive mechanism and
comprises an interlock device for preventing operation of the
drive mechanism, wherein the interlock device is deactivated when
the cleaning tool is coupled to the coupling section and provides
an electromagnetic signal to the second coil and the detector,
thereby enabling operation of the drive mechanism.
In accordance with another aspect of the invention, there is
provided a brushing or cleaning tool for an electric dental
cleaning device that is capable of use with a handle section
including a detector and a first coil configured to transmit and
receive electromagnetic waves to and from the cleaning tool, the
cleaning tool comprising a cleaning tool body for removably
coupling to the handle section; a cleaning section at a distal
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end of the cleaning tool body; a coupling section at a proximal
end of the cleaning tool body to effect coupling to the handle
section of the electric dental cleaning device; and an interlock
canceling element disposed in or on the cleaning tool body;
wherein the interlock canceling element comprises a transponder
tuned to a detector located in or on the handle section; and a
second coil configured to transmit and receive electromagnetic
waves to and from the first coil in the handle section; wherein
the interlock canceling element deactivates an interlock device
disposed in the handle section upon coupling the cleaning tool
with the handle section, thereby enabling operation of the dental
cleaning device.
Further objects, advantages, features and application
possibilities of the present invention will become apparent from
the subsequent description of embodiments illustrated in the
accompanying drawings. It will be understood that any features
described and/or represented by illustration, whether used
singularly or in any meaningful combination, form the
subject-matter of the present invention, irrespective of their
summary in the claims or their back reference.
In the drawings,
FIG. 1 is a perspective view of an electric toothbrush
having a handle section and a brush attachment attachable
thereto;
FIG. 2 is a schematic longitudinal sectional view of the
handle section of the electric toothbrush of FIG. 1, showing
arranged in the housing thereof the drive motor with gearing and
drive shaft, the storage battery for the drive motor and the
charging module for the storage battery;
FIG. 3 is a schematic view of an electric toothbrush,
showing a magnetic encoding of the brush attachment and a
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Hall sensor for detecting the encoding according to a pre-
ferred embodiment of the invention;
FIG. 4 is a sectional detail view of the toothbrush of
FIG. 3, showing the arrangement of the Hall sensor and the
magnetic encoding of the brush attachment which is coupled to
the handle section;
FIG. 5 is a schematic view of an electric toothbrush
having a magnetically encoded brush attachment and an LC
oscillator in the handle section to detect the encoding
according to a further preferred embodiment of the invention;
FIG. 6 is a sectional detail view of the toothbrush of
FIG. 5, showing the arrangement of the LC oscillator and the
magnetic encoding of the brush attachment which is coupled to
the handle section;
FIG. 7 is a schematic view of an electric: toothbrush
having a magnetically encoded brush attachment and a handle
section with reed contacts to detect the encoding according
to a further preferred embodiment of the invention;
FIG. 8 is a sectional detail view of the toothbrush of
FIG. 7, showing the arrangement of the reed contacts and the
magnetic encoding of the brush attachment which is coupled to
the handle section;
FIG. 9 is a schematic view of an electric toothbrush
having an optically encoded brush attachment and a handle
section with optical waveguides according to a further pre-
ferred embodiment of the invention;
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FIG. 10 is a sectional detail view of a toothbrush simi-
lar to FIG. 9, showing the arrangement of a light emitter and
a light detector in the handle section and an encoding of the
brush attachment in the form of an optical waveguide, with
the brush attachment and the handle section being shown in
coupled condition;
FIG. 11 is a top plan view of the optical waveguides at
the end, close to the handle section, of the brush attachment
of FIG. 10;
FIG. 12 is a sectional detail view of a toothbrush simi-
lar to FIG. 10, showing the arrangement of a light emitter
and a light detector in the form of a single integrated com-
ponent in the handle section and an encoding of the brush
attachment in the form of an optical waveguide, with the
brush attachment and the handle section being shown in
coupled condition;
FIG. 13 is a schematic view of an electric toothbrush
having an optically encoded brush attachment and a handle
section with color sensor for identification of the encoding
of the brush attachment according to a further preferred em-
bodiment of the invention;
FIG. 14 is a sectional detail view of the toothbrush of
FIG. 13, showing the arrangement of the color sensor in the
handle section and the color code of the brush attachment
which is coupled to the handle section;
FIG. 15 is a schematic view of an electric toothbrush
having a brush attachment encoded mechanically by its shape
in accordance with another preferred embodiment of the inven-
tion;
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CA 02649594 2009-01-13
FIG. 16 is a perspective view of the toothbrush of FIG.
15, showing the brush attachment as it is being coupled to
the handle section;
FIG. 17 is a sectional detail view of the toothbrush of
FIGS. 15 and 16, showing the arrangement of the encoding pro-
jections on the brush attachment and the sensing elements in
the form of electromechanical contacts for sensing the encod-
ing projections, with the brush attachment and the handle
section being shown in coupled condition;
FIG. 18 is a schematic view of an electric toothbrush
having an electromagnetically encoded brush attachment with a
transponder bonded thereto by adhesion or integrated therein
and a corresponding detection device in the handle section
according to a further preferred embodiment of the invention;
FIG. 19 is a perspective view of the toothbrush of FIG.
18;
FIG. 20 is a sectional detail view of a toothbrush simi-
lar to FIGS. 18 and 19, showing the arrangement of a
transponder chip in an encoding ring provided at the end of
the brush attachment, and a transmitter coil and a receiver
coil together with an associated electronic evaluation device
in the handle section, with the brush attachment and the
handle section being shown in coupled condition;
FIG. 21 is a schematic view of an electric toothbrush
having a capacitively encoded brush attachment and capacitor
plates in the handle section to detect the encoding of the
brush attachment according to a further preferred embodiment
of the invention;
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CA 02649594 2009-01-13
FIG. 22 is a detail view, in longitudinal section, of
the toothbrush of FIG. 21, showing the arrangement of the
dielectric portion of the brush attachment and the capacitor
plates in the handle section, with the brush attachment and
the handle section being shown in coupled condition;
FIG. 23 is a detail view, in cross section, of the
toothbrush taken along the line A-A of FIG. 22, showing the
arrangement of the dielectric portion of the brush attachment
and the capacitor plates in the handle section;
FIG. 24 is a sectional view of a handle section having a
longitudinally displaceable drive shaft and an electro-
mechanical sensing element for detecting the displacement of
the drive shaft according to a further preferred embodiment
of the invention; and
FIG. 25 is a sectional view of the handle section of
FIG. 23, showing the brush attachment in coupled condition.
The electric toothbrush shown in the Figures has a
handle section 1 with a closed housing 26 accommodating,
among other components and as illustrated in FIG. 2, in a
manner known in the art an electric motor 23, a storage
battery 24 adapted to be coupled to a charging station
through a charging module 25 disposed at the bottom, and a
control device 27 which may possess a printed circuit board
or microprocessor. Various brush attachments 2 are seatable
upon the end of the handle section 1 to function as brushing
or cleaning tools. By means of a coupling device 3 the brush
attachment 2 can be mechanically coupled to the handle sec-
tion 1 in order to transmit the driving motion of the elec-
tric motor to the brush head 4 of the brush attachment 2.
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The coupling device 3 which may be made of one or several
parts or pieces comprises a positive- or frictional-
engagement element for positioning the cleaning tool body in
its proper location and, in addition, a drive coupling which
transmits the driving motion of the drive to the brush head 4
of the brush attachment. Protruding from the end of the
handle section 1 is a drive shaft 28 adapted to be driven by
the drive motor 23 via a gearing 29 in a manner equally known
in the art. The drive shaft 28 has a coupling section 30
adapted to receive by positive or frictional engagement
therewith a complementary coupling section of a drive shaft
arranged in the cleaning tool 2, so that the driving motion
is transmitted, enabling the brush head 4 of the brush
attachment to be driven in a reciprocating, rotating,
oscillating, etc. manner.
The control device 27 has an electronic interlock device
100 which prevents operation of the drive of the handle sec-
tion unless a compatible brush attachment 2 is attached to
the handle section 1 which then releases the drive for opera-
tion. The key to this electronic interlock device 100 is an
encoding or interlock canceling element 7 provided on the
brush attachment 2.
To identify the brush attachment 2 when attached, provi-
sion is made on the handle section 1 for an encoding detec-
tion device 5 or a device for detecting the presence of the
interlock canceling element 7. In response to a signal from
this device or encoding detection device 5, the control
device 27 releases the drive for operation or not.
According to FIG. 3 a Hall sensor 6 is provided at the
coupling end of the handle section 1 in order to read,
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meaning identify, a magnetic encoding 7 on the brush
attachment 2. The magnetic encoding 7 is formed by a slip-on
ring 8 or a profiled ring 102 as disclosed in WO 99/20202,
which is provided at the coupling end of the brush attachment
2. The slip-on ring 8 is available in a variety of colors
containing either permanent magnets or like magnetic bodies
or, depending on the color, a different number of magnetic
particles or magnetic bodies differing in number, magnetic
orientation and/or magnetic field strength. As FIG. 4 shows,
the slip-on ring 8 or profiled ring 102 may be positioned in
its proper location on the body of the brush attachment
advantageously by positive engagement therewith, being in
particular snap-fitted thereto. This connection may be
constructed such that the ring 8 or profiled ring 102 is
securable to the body of the brush attachment in only one
predetermined orientation relative thereto. The Hall sensor
6 in the handle section 1 supplies a signal correlating with
the magnetic body or the number of magnetic particles or the
arrangement of the magnetic bodies, the value of this signal
being characteristic particularly of the respective brush
attachment 2 and suitable for further processing by the
control device in the handle section 1. The color of the
slip-on ring 8 makes it easy to remember which brush
attachment 2 is assigned to which user.
As FIG. 4 shows, the magnetic encoding 7 and the Hall
sensor 6 are disposed at the coupling ends of the brush
attachment and the handle section, respectively, lying advan-
tageously opposite each other in order to enable an accurate
detection to be accomplished.
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The electric toothbrushes according to the further em-
bodiments illustrated in the further Figures are constructed
basically in the same way as the toothbrush illustrated in
FIGS. 1 and 2, so that like components are assigned like
reference numerals, and the subsequent description deals only
with the different implementations of the encoding 7 of the
brush attachments 2 and the corresponding encoding detection
devices 5 on the handle section 1.
In the electric toothbrush illustrated in FIGS. 5 and 6
the brush attachment 2 carries likewise a slip-on ring 8
which is available in various colors and contains magnetic
particles differing in number depending on the color. To de-
tect the magnetic encoding of the brush attachment 2, the
recognition device 5 has an LC oscillator 9 which is disposed
at the coupling end of the handle section 1 and detuned by
the magnetic material in the brush attachment 2, thereby
supplying different frequencies assignable to the brush
attachments. The corresponding frequency signals are further
processed by the control device in the handle section 1 in
order to effect deactivation of the interlock device 100 or
also to set further operating parameters or to process and
indicate user-specific data.
As FIG. 6 shows, the LC oscillator has a coil 31 and a
capacitor 32 which are both disposed in the coupling end
region of the handle section. The coil is arranged directly
at the end. It may be mounted on a shoulder or the like of a
handle section chassis. The capacitor is positioned under-
neath the coil which faces the encoding ring 8. This enables
the encoding to be detected with precise accuracy.
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FIGS. 7 and 8 show a further embodiment of an electric
toothbrush in which the slip-on ring 8 of the brush attach-
ment 2 is provided with magnetic material only at defined
locations on its circumference (cf. FIG. 7a). The recogni-
tion device 5 comprises reed contacts 10 (cf. FIG. 8)
arranged in the handle section 1 at the handle end close to
the coupling device 3. When the brush attachment 2 is seated
down onto the handle section 1, defined actuation of the reed
contacts 10 takes place in accordance with the magnetic en-
coding of the slip-on ring 8. Depending on the combination
of contacts actuated, a specific brush attachment can be
identified. Here too, the slip-on ring 8 is a colored ring
to make it easier for the user to identify his or her
assigned brush. For enhanced response of the reed contacts,
the magnetic ring 8 or profiled ring 102 and the reed con-
tacts 10 have their respective ends in relative opposite
arrangement.
FIGS. 9 to 12 illustrate a preferred and advantageous
embodiment of an electric toothbrush in which the brush
attachment 2 is detected optically. The recognition device 5
comprises in the handle section 1 one or several optical
waveguides 11 exiting at the coupling end of the handle sec-
tion and experiencing defined interruptions or partial
obstructions by the brush attachment 2. The brush attachment
2 returns the light signal emitted from the optical waveguide
11 to the handle section 1 in encoded form, the encoded light
signal being directed through the optical waveguide 12 to a
sensor 13 which detects whether or not and/or in which inten-
sity light was returned and issues a corresponding recogni-
tion signal enabling the brush attachment to be identified
and/or the interlock device 100 to be actuated. For encoding
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and returning the light signal the brush attachment 2 may
possess a preferably likewise colored slip-on ring 8 in which
corresponding optical waveguides 14 are provided (cf. FIG.
9a). According to a further variant the light emitted from
the handle section 1 through the optical waveguide 11 is re-
flected individually by the brush attachment 2 or a corre-
spondingly encoded slip-on ring 8. Depending on the inten-
sity of reflection a particular brush attachment can be iden-
tified.
FIGS. 10 and 11 illustrate an advantageous variant of
the toothbrush of FIG. 9 with optical encoding of the brush
attachment and corresponding detection of the encoding by the
handle section 1. Provided in the handle section I directly
at its coupling end are a light emitter 33 and in circumfer-
entially offset position a light detector 34 which, through a
light exit opening 35 and a light entrance opening 36 pro-
vided at the end of the handle housing 26, look at the
coupled brush attachment 2. The light exit and light
entrance openings may be closed by a transparent material to
obtain a closed construction of the housing 26. Both the
emitter 33 and the detector 34 are connected to the control
and evaluation device 27 of the handle section 1. As FIG. 11
shows, the slip-on ring 8 of the brush attachment 2
accommodates an optical waveguide 37 receiving the light
emitted by the emitter 33 through a light entrance opening 38
(cf. FIG. 10), encoding and returning it through a light exit
opening 39 in the slip-on ring 8 to the detector 34 in the
handle section. The light may be guided in a variety of
ways, particularly by reflection. In this case the optical
waveguide may be configured as a reflector. The signal
issued by the light detector can be evaluated by the control
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device of the handle section 1 to identify the specific brush
attachment attached. The optical waveguide 37 extends in the
slip-on ring 8 in an approximately arcuate configuration
(cf. FIG. 11) To increase the possibilities of encoding,
multiple light processing devices may be provided. FIG. 11
shows a second optical waveguide 40. Encoding may be per-
formed by selection of a particular one of multiple light
detectors to which the respective optical waveguide returns
the received light. Encoding may also be performed by the
optical waveguides modifying or processing the received light
in different ways, in particular reflecting it in different
intensities. This is then converted into a corresponding
signal by the light detector.
FIG. 12 shows a further variant of optical encoding.
The light emitter 41 and the light detector 42 are con-
structed as an integral component. A partition wall 43 is
preferably provided to separate the light entrance and light
exit openings from each other. The light may be encoded in
particular by different magnitudes of reflection.
The embodiment of an electric toothbrush illustrated in
FIGS. 13 and 14 has similar to the preceding embodiments a
colored slip-on ring 8 secured to the end of the brush
attachment 2 close to the coupling device 3. The handle sec-
tion 1 has as recognition device 5 a color sensor 15 disposed
at the coupling end of the handle section 1 and oriented in
the direction of the colored slip-on ring 8. The color
sensor 15 detects the color of the slip-on ring 8, enabling
the brush attachment or the user of the toothbrush to be de-
termined. Conveniently, the color sensor is arranged
directly at the coupling end of the handle section 1 and
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oriented in the direction of the ring 8 when the brush
attachment sits on the handle section 1.
FIGS. 15, 16 and 17 illustrate an embodiment of an elec-
tric toothbrush in which the brush attachments 2 are recog-
nized mechanically. The colored slip-on ring 8 at the end of
the brush attachment 2 is an individually shaped encoding
body having preferably projections 16 or recesses in the form
of ribs or grooves. According to one embodiment of the in-
vention the shaped bodies extend as projections from the end
of the brush attachment, in particular essentially parallel
to the longitudinal axis of the brush attachment. At the
opposite end of the handle section 1 provision is made for
elastically deformable sensing elements in the form of
mechanical contacts 17 which are subjected to individual and
defined actuation by the brush attachment 2, meaning the pro-
jections 16 on the slip-on ring 8, so that the respective
brush attachment 2 is identified according to the combination
of actuated contacts. The shaped encoding bodies 16 have for
this purpose actuating or pressure application surfaces which
are arranged, oriented and/or configured such as to depress
the sensing element a predetermined amount when the brush
attachment is seated down on the handle section. The sensing
elements generate a signal responsive to the amount of
depression, in the simplest case an on-off signal according
to the contacting of the contact sections provided at the
sensing elements' ends. Actuation of the mechanical contacts
17 can be checked preferably electrically. To cover the
mechanical contacts 17 and shield them against the environ-
ment a soft membrane 18 may be placed over the mechanical
contacts 17 at the end of the handle section 1, through which
membrane the mechanical contacts 17 can be actuated by the
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projections 16. To accomplish this the housing 26 may be a
two-component injection molded part fabricated from hard and
soft plastics material.
FIGS. 18 to 20 illustrate a further embodiment of an
electric toothbrush in which the brush attachment 2 is de-
tected, i.e., identified by means of radio signals. The
brush attachment 2 is equipped with a transponder 19 which
may be bonded by adhesion to or on the brush attachment 2 as
in the form of a label referred to as smart label (FIG. 19).
Advantageously, the transponder 19 may also be contained in
the colored slip-on ring 8 at the end of the brush attachment
2 (cf. FIGS. 18a and 20). Provided in the handle section 1
is a detector 20 tuned to the transponder 19 and serving as
both a signal transmitter and a signal receiver. Via the
coil 45 the detector 20 in the handle section 1 initially
emits electromagnetic waves to the coil 44 connected to the
transponder 19 in order to supply power to the transponder 19
or its microchip. The transponder stores the energy and
sends a specific identification back to the detector 20 which
receives said identification, identifies it by means of its
electronic evaluation device 46 and delivers a corresponding
signal to the control device 27 of the handle section 1. The
coils 44 and 45 hence serve as both transmitter and receiver
facility. In a preferred embodiment the coils are disposed
in relative opposite arrangement at the ends of the brush
attachment 2 and the handle section 1, respectively (cf.
FIG. 20). The identification sent back by the transponder 19
enables the brush attachment 2 to be identified.
In the embodiment of an electric toothbrush illustrated
in FIGS. 21, 22 and 23, identification of the brush
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attachment 2 is performed capacitively. Provided in the
handle section 1 are two or several capacitor plates 21
between which a dielectric 22 is insertable to vary the
capacitance of the capacitor formed by the capacitor plates
21. The dielectric 22 is arranged at the end of the brush
attachment 2, and it may be in particular part of a slip-on
ring 8 fittable to the brush attachment 2. The dielectric
portion 22 extends preferably approximately parallel to the
longitudinal axis of the brush attachment, in particular
approximately parallel to its circumferential surface.
Provided in the circumferential surface of the handle housing
26 is an indentation 47 open towards the end and having the
form of a longitudinally parallel groove suitable for
engagement by the dielectric portion 22 of the brush
attachment as it is being coupled to the handle section 1.
The capacitor plates 21 are disposed in the interior of the
housing 26 on either side of the indentation referred to so
that the dielectric comes to lie between the capacitor
plates. The use of different dielectrics makes it possible
to encode the brush attachments 2 individually. Depending on
the capacitance or the variation in capacitance by the
different dielectrics, the corresponding brush attachment 2
can be identified. In an arrangement involving several
capacitors, an encoding is also obtainable by the arrangement
and/or number of dielectrics. It will be understood that the
capacitance of the capacitor can also be varied by a
variation in the distance between the capacitor plates 21,
which is accomplishable by providing the brush attachment 2
with mechanical elements acting on the capacitor.
FIGS. 24 and 25 illustrate a specific embodiment of the
invention involving a brush attachment encoded mechanically,
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that is, by its shape, and a mechanical detection of this en-
coding. The encoding of the brush attachment is part of its
coupling section 48 used for coupling the drive train 49 in
the brush section with the drive shaft 28 in the handle sec-
tion, to be more precise, with the coupling section 30
thereof. As FIG. 25 shows, the body of the brush attachment
is seated onto a brush mount 50 of the handle section 1 with
an exact fit so that the brush attachment sits on the handle
section 1 in a defined position. By means of detent noses
and corresponding recesses the brush attachment is secured in
place by making, for example, positive engagement with the
handle section, that is, its brush mount. Axial securing can
be accomplished also by frictional engagement. When the
brush attachment is pushed onto its mount, the coupling sec-
tions 48 and 30 in the drive train also make interfitting
engagement. The coupling sections are formed by a shaft stub
and a complementary recess in the form of a blind-end hole in
the opposite shaft end, thus enabling the shaft stub to be an
exact fit within the blind-end type shaft bore. Torque
transmission takes place preferably by positive engagement.
The coupling sections have complementary mating surfaces
51 and 52, preferably in the form of a flattening on the
drive shaft 28 and a corresponding bore secant surface in the
recess 53 of the drive shaft portion 54 of the brush attach-
ment. A spline or a splined-shaft profile may also be pro-
vided for torque transmission.
The brush attachment, in particular the coupling section
48, has as encoding an actuating surface 55 which in coupled
condition is in engagement with an associated engagement sur-
face on the handle section 1, in particular on the coupling
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section 30 of the drive shaft 28. The actuating surface 55
mates with the engagement surface 56 in such manner that a
predetermined interaction occurs between these two surfaces
in coupled condition. In particular the actuating surface 55
is arranged and aligned so as to exert a predetermined
pressure on the engagement surface 56. To be able to read or
scan the configuration of the actuating surface 55, the asso-
ciated engagement surface 56 is formed on a movable probe
element, producing as interaction a predetermined movement of
the probe element. It will be understood that it is also
possible to detect a force, but a movement can be detected
with greater ease. Different configurations of the actuating
surfaces 56 are translated into different movements of the
associated engagement surface 56 of the probe element.
As probe element the drive shaft 28 of the handle sec-
tion is preferably used. The drive shaft is mounted longitu-
dinally displaceably and preferably biased into protrusion
from the handle section by means of biasing members. When
the brush attachment 2 is seated down on the handle section
the brush attachment's actuating surface 55 urges the drive
shaft 28 a predetermined distance into the interior of the
handle section 1. The displacement is detected by a dis-
placement or motion sensor which may embody a variety of
configurations, being operable for example as a light
barrier. Other displacement sensors may also be employed.
Preferably provision may be made for an elastically deform-
able sensing element with electromechanical contact of the
type previously described with reference to FIG. 17. The
drive shaft 28 preferably sits with a lug, preferably with
its end remote from the coupling section 30, on the sensing
element 57. The sensing element may at the same time serve
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as biasing member. When the drive shaft 28 is pressed down,
the sensing element produces a corresponding signal, in par-
ticular opening or closing a corresponding contact. By
suitably constructing the sensor or sensing element or multi-
ple sensing elements the encoding of the brush attachment can
be read or scanned.
As FIG. 25 shows, the actuating surface 55 is formed by
the bottom surface of the blind-end type recess 53 in the
brush attachment's drive shaft. The associated engagement
surface is formed by the end of the drive shaft 28. While
being reversible, this arrangement is preferably configured
as illustrated.
Alternative embodiments of the actuating and engagement
surfaces 55 and 56, respectively, are possible. In a further
aspect of the invention provision may be made for conical
mating surfaces. Other configurations may also be
contemplated.
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