U.S. patent application number 12/520051 was filed with the patent office on 2010-02-25 for toothbrush and attachment therefor.
Invention is credited to Gerhard Kressner.
Application Number | 20100043156 12/520051 |
Document ID | / |
Family ID | 39150678 |
Filed Date | 2010-02-25 |
United States Patent
Application |
20100043156 |
Kind Code |
A1 |
Kressner; Gerhard |
February 25, 2010 |
TOOTHBRUSH AND ATTACHMENT THEREFOR
Abstract
An electric toothbrush includes a handpiece with a drive shaft
and attachment, which has a working head and a coupling member
connecting the working head and the handpiece. The coupling member
of the attachment contains a plug-on shaft to engage the drive
shaft. An attachment coupling part is axially movable in a
longitudinal direction to produce an unlocking or locking movement
of the plug on shaft in the transverse direction. The connection
can be released and re-established by axial push-on and pull-off
movements. A transversely movable engagement part of a coupling
contour of the plug-on shaft of the attachment and an actuating
part provided on the coupling member are movable in the attachment
longitudinal direction, such that relative movement of the
actuating part and engagement part in the longitudinal direction
produces an unlocking or locking movement of the engagement part in
a direction transverse to the attachment longitudinal
direction.
Inventors: |
Kressner; Gerhard;
(Altenstadt, DE) |
Correspondence
Address: |
FISH & RICHARDSON PC
P.O. BOX 1022
MINNEAPOLIS
MN
55440-1022
US
|
Family ID: |
39150678 |
Appl. No.: |
12/520051 |
Filed: |
December 7, 2007 |
PCT Filed: |
December 7, 2007 |
PCT NO: |
PCT/EP07/10673 |
371 Date: |
June 18, 2009 |
Current U.S.
Class: |
15/22.1 |
Current CPC
Class: |
A61C 17/222
20130101 |
Class at
Publication: |
15/22.1 |
International
Class: |
A46B 13/02 20060101
A46B013/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2006 |
DE |
102006060133.5 |
Claims
1-26. (canceled)
27. An attachment mountable to an electric toothbrush handpiece
having a drive shaft, the attachment comprising: a working head; a
coupling member joined to the working head and configured to mount
to the toothbrush handpiece; and a plug-on shaft disposed in the
coupling member and defining a coupling contour comprising an
engagement part configured to lock with the drive shaft; wherein
the engagement part is movable to produce one of a locking movement
and an unlocking movement in a direction transverse to a
longitudinal attachment axis in response to axial movement of the
coupling member relative to the longitudinal attachment axis.
28. The attachment according to claim 27, wherein the coupling
member further comprises an actuating part comprising an unlocking
section configured to move the engagement part into an unlocked
position during an axial movement of the actuating part away from
the working head.
29. The attachment according to claim 28, wherein the engagement
part and the actuating part define cooperative beveled surfaces
configured to move the engagement between locked and unlocked
positions as the engagement part rides over the actuating part.
30. The attachment according to claim 28, wherein the engagement
part defines a detent contour configured to be radially movable by
the actuating part.
31. The attachment according to the claims 28, wherein the
engagement part includes a detent ring which is radially expandable
by cooperation with a tapered surface on the actuating part.
32. The attachment according to claim 28, wherein the actuating
part comprises a slide which is axially displaceable relative to
the longitudinal axis of the attachment.
33. The attachment according to claim 28, wherein the actuating
part is connected to a sleeve-shaped coupling insert slideably
disposed within the coupling member
34. The attachment according to the claim 33, wherein the coupling
insert is configured such that axial movement of the coupling
insert relative to the longitudinal attachment axis moves the
engagement section between locked and unlocked positions in a
direction transverse to the longitudinal attachment axis.
35. The attachment according to claim 34, wherein the coupling
insert is configured as one of a cylindrical mount and a conical
mount, and is configured to receive a complementary connecting part
of the toothbrush handpiece.
36. The attachment according to the claim 35, wherein the conical
mount of the coupling insert has a bevel of more than 7 degrees and
is configured to be non-self-locking.
37. The attachment according to claim 33, wherein the plug-on shaft
of the coupling member comprises one of a detent clip and a spring
catch configured to slide along the drive shaft and to rebound
elastically to snap into engagement while the coupling member is
being mounted onto the toothbrush handpiece.
38. The attachment according to claim 37, wherein the one of the
detent clip and the spring catch is unseatable from an engaged
position by a relative axial movement of the actuating member and
the coupling insert.
39. The attachment according to claim 27, wherein the coupling
contour comprises one of a conical faying surface and a plurality
of circumferentially spaced faying surfaces.
40. The attachment according to claim 27, wherein the coupling
contour comprises one of a conical faying surface defining a bevel
of more than 7 degrees.
41. An attachment to be connected to a toothbrush handpiece having
a drive shaft, the attachment comprising: a working head; a
coupling member joined to the working head and mountable on the
toothbrush handpiece; and a plug-on shaft disposed in the coupling
member and defining a coupling contour configured to engage the
drive shaft of the toothbrush handpiece, wherein the coupling
contour defines at least one conical faying surface configured to
engage with a complementary faying surface on the drive shaft of
the toothbrush handpiece.
42. The attachment according to claim 41, wherein the conical
faying surface defines a bevel of more than 7 degrees.
43. The attachment according to claim 41, wherein the coupling
member comprises a coupling insert in the form of a sleeve
configured to axially lock the coupling member onto a neck of the
toothbrush handpiece with the complementary conical faying surfaces
of the plug-on shaft and the drive shaft engaged.
44. The attachment according to claim 41, wherein the coupling
contour is axially biased away from the working head.
45. An attachment to be connected to a toothbrush handpiece having
a drive shaft, the attachment comprising: a working head; a
coupling member joined to the working head and mountable on the
toothbrush handpiece; and a plug-on shaft disposed within the
coupling member, and defining two coupling contours, each contour
configured to engage a drive shaft of a respective toothbrush
handpiece.
46. The attachment according to claim 45, wherein: a first one of
the two coupling contours comprises an engagement part movable in a
direction transverse to a longitudinal axis of the attachment to
lock with a drive shaft of a first toothbrush handpiece; and a
second one of the two coupling contours comprising at least one
conical faying surface configured to engage with a complementary
conical faying surface on a drive shaft of a second toothbrush
handpiece.
47. The attachment according to claim 46, wherein one of the
engagement part of the first coupling contour and an actuating part
disposed on the coupling member is axially movable relative to an
attachment longitudinal axis, the engagement part configured to
cooperate with the actuating part such that relative axial movement
of the actuating part and the engagement part produces an unlocking
or locking movement of the engagement part in a direction
transverse to the attachment longitudinal axis, and wherein the
second coupling contour comprises at least one conical beveled
surface defining a bevel of more than 7 degrees.
48. The attachment according to claim 45, further comprising an
adapter connected to the plug-on shaft and defining one of the two
coupling contours is defined.
49. An electric toothbrush handpiece configured to be removably
connected to an attachment comprising a plug-on shaft and a
coupling contour, wherein the handpiece comprises a neck and a
drive shaft configured to engage the plug-on shaft of the
attachment, the drive shaft defining a conical coupling contour
with a bevel of more than 7 degrees.
50. The toothbrush handpiece according to claim 49, wherein the
coupling contour is substantially free of undercuts and axially
effective snap-action connections.
51. The toothbrush handpiece according to claim 49, wherein the
drive shaft is axially displaceable relative to the neck of the
toothbrush handpiece in the direction of a toothbrush handpiece
longitudinal axis
52. The toothbrush handpiece according to claim 49, wherein the
coupling contour of the drive shaft defines a locking contour
extending in a direction transverse to the drive shaft longitudinal
direction, the locking contour being connected to an adapter
seatable onto the drive shaft and defining a coupling contour
configured to couple with the attachment plug-on shaft.
Description
TECHNICAL FIELD
[0001] This invention relates to an electric toothbrush having a
handpiece and an attachment mountable thereon.
BACKGROUND
[0002] EP 0 500 537 B1 discloses an electric toothbrush on which
the attachment brush is connected on the one hand to a front-end
shank part of the toothbrush handpiece and on the other hand to a
drive shaft projecting therefrom. For this purpose the attachment
brush has radially resilient detent hooks which can be locked in
place in corresponding detent notches on the handpiece.
[0003] DE 103 52 993 A1 discloses in addition an electric
toothbrush on which the attachment brush is fixed only directly to
the drive shaft which projects at the front end out of the
toothbrush handpiece. For this purpose the attachment brush has a
coupling member with an inner recess of the blind-hole type into
which an on the whole sleeve-shaped mount is inserted. Said mount,
into which the drive shaft can be inserted with a snug fit,
includes several spring elements which are radially resilient and
intended to ensure a zero-play connection between the attachment
brush and the drive shaft.
[0004] Excess play in attachment couplings and drive mechanisms can
adversely affect handpiece and attachment life and performance. For
example, the attachment can become separated due to the vibrations
of the electric toothbrush drive and the forces applied by
brushing. Accordingly, improvements are sought in electric
toothbrushes and attachment tools for treating the oral cavity.
SUMMARY
[0005] One aspect of the invention features an electric toothbrush
with an improved handpiece and an improved attachment including an
easy-to-couple and high tolerance connection between the plug-on
shaft of the attachment and the drive shaft of the toothbrush
handpiece, The connection couples two sections of the drive train
with zero play, and yet can be easily released and re-established.
The attachment can include different drive shaft configurations in
order to be suitable for use with different toothbrush
handpieces.
[0006] One aspect of the invention features an attachment connected
to a toothbrush handpiece with a drive shaft. The attachment
features a working head, a coupling member joined to the working
head and mountable on the toothbrush handpiece, and a plug-on shaft
for driving the working head. The plug-on shaft is disposed in the
coupling member and defines a coupling contour for coupling by
positive engagement with the drive shaft of the toothbrush
handpiece. Additionally, the coupling contour includes an
engagement part movable in a direction transverse to the attachment
longitudinal direction and configured to lock with the drive shaft.
The transversely movable engagement part is movable in response to
movement of the coupling member in the attachment longitudinal
direction, to produce an unlocking or locking movement of the
engagement part in a direction transverse to the attachment
longitudinal direction.
[0007] In some implementations, the coupling member further
features an actuating part including an unlocking section. The
unlocking section is arranged and configured such that during an
axial movement of the actuating part away from the working head the
unlocking section is movable into engagement with the engagement
part and capable of moving the engagement part into an unlocked
position.
[0008] In some cases, the engagement part and the actuating part
define a pair of beveled surfaces configured to produce the
unlocking and locking movement while the engagement part rides over
the actuating part.
[0009] In some cases, the engagement part defines a transverse axis
and a detent contour on a protruding end of the engagement part.
The protruding end is configured to be radially movable by the
actuating part.
[0010] In some cases, the engagement part includes a detent ring
which is radially extensible and compressible, and has a
wedge-shaped surface. Additionally, the dentent ring is radially
extensible by a wedge-shaped surface on the actuating part when the
detent ring rides axially over the actuating part in the attachment
longitudinal direction.
[0011] In some cases, the actuating part is connected to a
sleeve-shaped coupling insert provided in the coupling member. The
coupling insert connects the coupling member to the toothbrush
handpiece and is axially displaceable relative to the coupling
member in the attachment longitudinal direction.
[0012] In some cases, the coupling insert is connected to the
toothbrush handpiece by one of positive engagement and frictional
engagement. Additionally, an axial movement of the coupling insert
relative to the coupling member produces unlocking and locking
movements of the engagement section in a direction transverse to
the attachment longitudinal direction.
[0013] In some cases, the coupling insert forms a sleeve having one
of a cylindrical mount and a conical mount configure to receive a
complementary connecting part of the toothbrush handpiece.
[0014] In some cases, the actuating part features a slide which is
axially displaceable in the longitudinal direction of the
attachment.
[0015] In some cases, the conical mount of the coupling insert has
a bevel of more than 7.degree. and is configured in a
non-self-locking manner.
[0016] In some cases, the plug-on shaft of the coupling member
forms one of a detent clip and a spring catch configured to slide
along the drive shaft while the coupling member is being plugged
onto the toothbrush handpiece and rebound elastically to snap into
engagement.
[0017] In some cases, the one of the detent clip and the spring
catch is unseatable from its snapped-in position by a relative
axial movement between the actuating member and the coupling
insert.
[0018] In some implementations, the coupling contour has one of a
conical faying surface and a plurality of circumferentially spaced
faying surfaces.
[0019] In some cases, the conical faying surface defines a bevel of
more than 7.degree..
[0020] Another aspect of the invention features an attachment
connected to a toothbrush handpiece having a drive shaft. The
attachment features a working head, a coupling member joined to the
working head and mountable on the toothbrush handpiece, a plug-on
shaft disposed in the coupling member and connectable to the
working head, and a coupling contour on the plug-on shaft
configured to engage the drive shaft of the toothbrush handpiece.
The coupling contour includes at least one conical faying surface
configured to engage with a complementary faying surface on the
drive shaft of the toothbrush handpiece.
[0021] In some cases, the conical faying surface includes a bevel
of more than 7.degree..
[0022] In some cases, the coupling member features a sleeve-shaped
coupling insert configured to axially lock the coupling member onto
a neck of the toothbrush handpiece with the conical faying surfaces
on the plug-on shaft and the drive shaft in relative
engagement.
[0023] In some cases, the coupling contour is axially biased away
from the working head.
[0024] Another aspect of the invention features an attachment to be
connected to a toothbrush handpiece having a drive shaft. The
attachment features a working head, a coupling member having an
actuating part joined to the working head and mountable on the
toothbrush handpiece, and a plug-on shaft within the working head
and the coupling member. The plug-on shaft features a coupling
contour configured to engage a drive shaft provided on the
toothbrush handpiece and includes two coupling contours configured
to engage different drive shafts of different toothbrush
handpieces.
[0025] In some implementations, a first one of the two coupling
contours has an engagement part movable in a direction transverse
to the longitudinal direction of the attachment for locking with
the drive shaft. Additionally, a second one of the two coupling
contours includes at least one conical faying surface for
engagement with a complementary conical faying surface on the drive
shaft of the toothbrush handpiece.
[0026] In some cases, the engagement part of the first coupling
contour and an actuating part disposed on the coupling member are
movable in the attachment longitudinal direction. The engagement
part is engageable with the actuating part and configured such that
relative movement of the actuating part and the engagement part in
the attachment longitudinal direction produces an unlocking or
locking movement of the engagement part in a direction transverse
to the attachment longitudinal direction. Additionally, the second
coupling contour has at least one conical beveled surface defining
a bevel of more than 7.degree..
[0027] In some implementations, one of the two coupling contours is
defined on an adapter attachable to the plug-on shaft.
[0028] Another aspect of the invention features a toothbrush
handpiece connected to an attachment having a plug-on shaft and a
coupling contour. The handpiece features a neck, and a drive shaft
insertable into the plug-on shaft of the attachment and defining a
conical coupling contour with a bevel of more than 7.degree..
[0029] In some implementations, the coupling contour is configured
to be devoid of undercuts and axially effective snap-action
connections.
[0030] In some implementations, the drive shaft is axially
displaceable relative to the neck of the toothbrush handpiece in
the toothbrush handpiece longitudinal direction and biasing means
are provided for axially biasing the coupling contour of the drive
shaft.
[0031] In some implementations, the coupling contour of the drive
shaft includes a locking contour extending in a direction
transverse to the drive shaft longitudinal direction. The locking
contour is non-releasably locked to an adapter which is seatable
onto the drive shaft and has on its outer surface a coupling
contour for coupling with the plug-on shaft of an attachment.
[0032] Another aspect of the invention features an attachment to be
connected to a toothbrush handpiece having a drive shaft. The
attachment includes a working head and a coupling member joined to
the working head and mountable on the toothbrush handpiece; and a
plug-on shaft for driving the working head disposed in the coupling
member and defining a coupling contour for coupling by positive
engagement with the drive shaft of the toothbrush handpiece. The
coupling contour includes an engagement part movable in a direction
transverse to the attachment longitudinal direction and configured
to lock with the drive shaft; and wherein the transversely movable
engagement part is movable in response to movement of the coupling
member in the attachment longitudinal direction, to produce an
unlocking or locking movement of the engagement part in a direction
transverse to the attachment longitudinal direction.
[0033] In a particular implementation, a tubular coupling member is
axially movable in the attachment longitudinal direction and to
convert axial movement into an unlocking or locking movement of the
coupling of the drive train in a direction transverse to the
attachment longitudinal direction for the attachment to engage and
disengage the handpiece. The coupling member enables a firm and
vibration-resistant connection between the attachment and the
handpiece. while enabling the connection to be released and
re-established by the axial push-on and pull-off movement.
[0034] In some implementations, a transversely movable engagement
part of a coupling contour of the plug-on shaft of the attachment
and/or an actuating part provided on the coupling member of the
attachment are movable in the attachment longitudinal direction,
with the engagement part being engageable with the actuating part
such that a movement of the actuating part and/or of the engagement
part in the attachment longitudinal direction produces an unlocking
or locking movement of the engagement part in a direction
transverse to the attachment longitudinal direction. If the
coupling contour of the plug-on shaft of the attachment is locked
onto the drive shaft of the handpiece, the attachment or an
actuating part connected thereto can be moved axially in the
attachment's longitudinal direction relative to the locked coupling
contour, whereby the engagement part of the coupling contour is
unlocked in a direction transverse to the toothbrush longitudinal
direction to enable the plug-on shaft to be pulled with the
attachment off the drive shaft of the toothbrush handpiece.
[0035] This attaching or connecting mechanism permits even
non-self-locking connecting or faying contours, in particular those
with a more pronounced taper, to be provided at the interface of
the drive train because fixed connection is assured by the locking
movement which takes place in a direction transverse to the
attachment's longitudinal direction. In particular, the interface
of the drive train can thus be rendered insensitive to
tolerances.
[0036] To achieve simple operation of the attachment and be able to
readily pull the attachment off the toothbrush handpiece, another
aspect of the invention features the actuating part having an
unlocking section arranged and configured such that during an axial
movement of the actuating part away from the working head, the
unlocking section is engageable with the engagement part of the
plug-on shaft and forces the engagement part into an unlocked
position. In other words, the actuating part is arranged and
configured such that the actuating part automatically unlocks the
coupling insert when the attachment is being separated from the
toothbrush handpiece.
[0037] In a particular implementation, the attachment includes a
working head and
[0038] a coupling member joined to the working head and mountable
on the toothbrush handpiece. A plug-on shaft is disposed in the
coupling member and connectable to the working head a defines a
coupling contour configured to engage the drive shaft of the
toothbrush handpiece, wherein the coupling contour includes at
least one conical faying surface configured to engage with a
complementary faying surface on the drive shaft of the toothbrush
handpiece.
[0039] In a particular implementation, the engagement part of the
coupling contour of the plug-on shaft and/or the actuating part
defines a wedge-shaped surface, which produces an unlocking
movement while the engagement part rides over the actuating part. A
pair of plane wedge-shaped surfaces may be provided, but it is also
possible to use a pair of beveled surfaces arched in a spherical or
concave configuration in the manner of a cam or a cam-type control
surface on the one hand and an actuating member riding over it on
the other hand. When the engagement part rides over the actuating
part as a result of the axial relative movement, the axial movement
causes an unlocking movement in a direction transverse to the axial
direction.
[0040] It is also possible, in reversal of the kinematics, to
provide for the actuating part to affect not the unlocking but the
locking of the coupling contour of the plug-on shaft or the
engagement part connected thereto. In this case the engagement part
in its initial position may adopt, or be biased into, a non-locking
position. When the attachment is plugged onto the toothbrush
handpiece, the engagement part of the coupling is forced into its
locking position by way of the actuating part.
[0041] The coupling contour of the plug-on shaft can thus be
configured to be self-locking while the attachment is being seated
onto the toothbrush handpiece, is then released by means of the
actuating part while the attachment is being removed again.
[0042] In a particular implementation, the engagement part forms a
spring catch or a detent clip which, while the coupling member is
being plugged onto the toothbrush handpiece, slides along the
connecting member of the drive shaft of the toothbrush handpiece,
rebounds elastically in the process and, upon reaching the fully
plugged-on position, snaps into place by positive engagement. When
the attachment is to be removed again from the toothbrush
handpiece, the spring catch or the detent clip is unseated from its
snapped-in position by a relative axial movement between the
actuating part and the spring catch or detent clip.
[0043] Generally, the engagement part may be configured in a
variety of ways. According to a particular implementation, the
engagement part defines a detent contour in the form of a detent
hook, which is located at the protruding end of an engagement
finger advantageously resilient and/or pivotal about a transverse
axis and is radially movable by the actuating part. At least one
engagement finger may be integrally made of one piece with the body
of the coupling section of the plug-on shaft and be isolated from
the rest of the body, for example, by longitudinal slits in order
to be resilient in relation to the remaining body. The engagement
finger may also be part of a separate coupling attachment secured
to the plug-on shaft.
[0044] In some implementations, an engagement part can also be
provided in the form of a rocker which at its one end has a
suitable detent contour, generally in the form of a detent hook for
locking engagement with the toothbrush handpiece, and at its other
end forms an actuating section which is movable into engagement
with the actuating part. In this case, too, the engagement part may
be integrally made of one piece with the body of the coupling
insert, generally by way of a flexible connecting bar in the middle
section of the rocker.
[0045] Other implementations may comprise a slotted detent ring on
the plug-on shaft, where the ring is radially compressible and
extensible. Compression can be accomplished particularly by biasing
the detent ring, while conversely an extension or widening of the
detent ring can be affected, for example, by way of a pair of
beveled surfaces on the detent ring and the actuating part.
[0046] The actuating part for unlocking or, if applicable, for
locking the coupling of the drive train may be configured in a
variety of ways. In a particular implementation, the actuating part
is configured for automatic operation so that it operates
automatically when the attachment is being pulled off or plugged
on, unlocking or locking the engagement part of the drive train
coupling automatically.
[0047] In some implementations, the actuating part may be connected
to a coupling insert, generally being integrally made of one piece
therewith, where coupling insert is arranged in the tubular
coupling member of the attachment and serves to be locked with the
neck of the toothbrush handpiece by positive and/or frictional
engagement in order to hold the attachment on the toothbrush
handpiece. Furthermore, this coupling insert of the attachment is
axially displaceable relative to its coupling member in the
attachment longitudinal direction and connected to an engagement
part which is lockable with the neck of the toothbrush handpiece by
positive or frictional engagement, such that the coupling insert
experiences an axial movement in the attachment longitudinal
direction relative to the tubular coupling member of the attachment
when the attachment is pulled off and/or plugged onto the
toothbrush handpiece. When the attachment is pulled off or plugged
on, this configuration produces automatically also an axial
actuating movement of the actuating part for the drive shaft
coupling which is converted into the actuating movement of the
engagement part of the drive train coupling in a direction
transverse to the attachment longitudinal axis.
[0048] In this arrangement, the actuating part is configured in the
form of a pulling hook which protrudes from the frontal end of the
preferably sleeve-shaped coupling insert and extends as far as the
drive train coupling for engagement therewith the engagement part
of the coupling contour of the plug-on shaft.
[0049] In a particular implementation, the attachment is configured
with regard to said coupling insert in such a way that the axial
movement of the coupling insert relative to the coupling member
and/or an actuating part provided thereon produces an unlocking
and/or locking movement of the engagement section of the coupling
insert in a direction transverse to the attachment longitudinal
direction. If the coupling insert or its engagement section is
locked onto the toothbrush handpiece, it is first necessary for the
attachment or an actuating part connected thereto to be moved
axially substantially in the attachment longitudinal direction
relative to the locked coupling insert, whereby the coupling insert
initially does not move relative to the toothbrush handpiece on
account of its being locked thereto. Not until the axial relative
movement has released the lock is it possible for the coupling
insert to be pulled together with the attachment off the toothbrush
handpiece. This two-stage attaching or connecting mechanism permits
even non-self-locking connecting or faying contours to be provided
at the interface between the toothbrush handpiece and the coupling
insert because fixedly securing is assured nevertheless by the
locking movement which takes place in a direction transverse to the
attachment longitudinal direction.
[0050] As an alternative to the fastening of the actuating part of
the drive train coupling to such a coupling sleeve, it is also
possible generally for the actuating part to be configured as a
part separate from the connecting means of the tubular coupling
member on the handpiece neck. For example, the actuating part could
be in the form of a slide mounted for displacement on the coupling
member, said slide preferably including a fingertip control and/or
being displaceable, for example, by a user's thumb in the
attachment longitudinal direction relative to the tubular coupling
member in order to release or lock the drive train coupling.
[0051] The coupling contour of the drive train coupling may be
generally shaped in a variety of ways. In a particular
implementation, the coupling contour of the plug-on shaft defines a
conical mount which widens in a direction away from the working
head of the attachment, has a bevel of more than 7.degree. and is
accordingly no longer configured to be self-locking, while in
corresponding manner the stub-shaped connecting member of the drive
shaft of the toothbrush handpiece, which conventionally projects at
the front end, may be conically shaped in corresponding manner with
a bevel of more than 7.degree.. In reversal of the kinematics, so
to speak, it is generally also possible to reverse this arrangement
and provide on the drive shaft of the handpiece a conical mount,
into which the similarly conical plug-on shaft of the attachment
can be plugged. Said relatively pronounced taper of the connecting
members of the two shafts renders the connection insensitive to
tolerances because any difference in diameter can be compensated
for by a corresponding axial movement.
[0052] Such a conical configuration of the interface faying
surfaces of the drive train coupling is advantageous in connection
with the previously described locking of the two shaft parts by
means of an engagement part movable in a direction transverse to
the attachment longitudinal direction, because such a locking
prevents an unwanted disengagement of the relatively cooperating
coupling contours even in the presence of a non-self-locking
configuration. Nevertheless, the pair of conical faying surfaces
enables a firm and zero-play shaft connection to be accomplished
which accommodates tolerances.
[0053] Additionally, said conical configuration of the faying
surfaces of the drive train interface may also be used to advantage
with a locking of the tubular coupling member of the attachment
brush on the neck of the toothbrush handpiece. By locking the
tubular coupling member onto the toothbrush handpiece by positive
and/or frictional engagement, also the coupling contours of the
plug-on shaft and the drive shaft are securely held against each
other without an unintentional disengagement being possible. This
has the advantage if the coupling contours of the two shaft parts
are biased into their coupling position, which can be accomplished,
for example, by guiding the drive shaft axially displaceably in the
toothbrush handpiece and biasing it toward the attachment brush by
means of a suitable spring device. It is also possible for the
plug-on shaft in the attachment brush or at least for the end piece
carrying the coupling contour to be biased by a suitable spring
away from the working head of the attachment brush, i.e., toward
the toothbrush handpiece. In a particular implementation, the
plug-on shaft may include two shaft parts slidable one into the
other and out of each other in the manner of a telescopic
shaft.
[0054] The coupling contours on the plug-on shaft and/or the drive
shaft can be implemented in a way affording particular ease of
manufacture by the absence of any undercuts and axially effective
snap-action connections on the coupling contour of the plug-on
shaft and the complementary coupling contour of the drive shaft.
Accordingly, the two shaft parts can be simply plugged one into the
other, with the torque transmission being made possible by the
conical faying surface which is generally not symmetrical about the
axis. In this arrangement, the axial securing of the coupling
contours one upon the other is ensured by the previously described
locking of the tubular coupling member of the attachment onto the
neck of the toothbrush handpiece.
[0055] In a particular implementation, the plug-on shaft of the
attachment is configured in respect of its coupling section in such
a way that it can be coupled with different drive shafts of
toothbrush handpieces.
[0056] In some cases, the plug-on shaft of the attachment may
include two separate, independently effective coupling contours,
each for positive-engagement coupling to different drive shafts of
different toothbrush handpieces. In this context, separate and
independently effective means advantageously that a drive shaft of
the toothbrush handpiece to be coupled to the plug-on shaft is
moved into force- or torque-transmitting engagement with a
respective one of the two coupling contours.
[0057] In a particular implementation, a first one of the two
coupling contours has an engagement part movable in a direction
transverse to the attachment longitudinal direction for locking, by
positive and/or frictional engagement, with the drive shaft of the
toothbrush handpiece, while a second one of the two coupling
contours includes a conical faying surface for engagement with an
equally conical faying surface on the drive shaft of the toothbrush
handpiece, which is devoid of undercuts and devoid of axially
effective snap-action connections. In a particular implementation,
the first one of the two coupling contours may include a
transversely movable engagement part, for example, a detent finger,
a split detent ring or a pivotal part which is actuatable by way of
the axially movable actuating part particularly in the form of a
pulling hook secured to the aforedescribed coupling sleeve. The
second one of the two coupling contours may be non-self-locking in
the manner previously described and it may have a taper with a
bevel of more than 7.degree..
[0058] Another aspect of the invention an electric toothbrush
attachment including a working head and a coupling member joined to
the working head. The attachment is mountable on the toothbrush
handpiece, with a plug-on shaft for driving the working head
disposed in the coupling member and having a coupling contour for
coupling by positive engagement with a drive shaft of the
toothbrush handpiece. In some cases, the toothbrush handpiece
includes a drive shaft insertable into the plug-on shaft of the
attachment with a close fit. In various cases, the attachment can
be an attachment brush for dental cleansing, interproximal cleaning
devices, gum massage heads or other oral care instrument.
[0059] In a particular implementation, the handpiece and attachment
comprises complementary connection tapers to permit more lenient
tolerances. The drive shaft of the handpiece and the plug-on shaft
of the attachment also comprise complementary tapered connection
surfaces to enable a connection which allows more lenient
tolerances.
DESCRIPTION OF DRAWINGS
[0060] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and the description below.
Other features, objects, and advantages of the invention will be
apparent from the description and drawings, and from the
claims.
[0061] FIG. 1 is a fragmentary view, in longitudinal section, of
one implementation of an electric toothbrush showing the front-end
connecting member of the toothbrush handpiece and the attachment
brush seated thereon, with the coupling insert, which is seated in
the tubular coupling member of the attachment brush, being shown in
its locked position.
[0062] FIG. 2 is a longitudinal sectional view of the toothbrush of
FIG. 1, which is turned through 90.degree. compared to the
illustration in FIG. 1.
[0063] FIG. 3 is a sectional view of the toothbrush of FIGS. 1 and
2 in the region of the catch mechanism between the coupling insert
in the attachment brush and the neck of the toothbrush
handpiece.
[0064] FIG. 4 is a simplified and enlarged fragmentary view, in
longitudinal section, of the electric toothbrush of FIGS. 1 to 3,
showing the connection of the plug-on shaft of the attachment brush
with the drive shaft of the handpiece of the toothbrush in more
detail.
[0065] FIG. 5 is a fragmentary view, in section, of the drive train
coupling in the coupling member of an attachment brush according to
another implementation in which the coupling has a pivotally
mounted locking arm with a cam-type actuating part.
[0066] FIG. 6 is a fragmentary view, in section, of the drive train
coupling in the coupling member of an attachment brush according to
another implementation in which the coupling has a pivotally
mounted locking arm which is mounted for pivotal movement on a
spring part on a side opposite the pulling hook of the actuating
part.
[0067] FIG. 7 is a fragmentary view, in section, of the drive train
coupling in the coupling member of an attachment brush according to
another implementation in which the coupling has a pivotally
mounted locking arm, with the pulling hook of the actuating part
being arranged to act on a side opposite the detent projection of
the locking arm.
[0068] FIG. 8 is a fragmentary view, in section, of the drive train
coupling in the coupling member of an attachment brush according to
another implementation in which the coupling includes a split
extensible detent ring.
[0069] FIG. 9 is a fragmentary view, in longitudinal section, of
another implementation in which solely the coupling insert in the
coupling member of the attachment brush is locked with the
toothbrush handpiece, while the drive train coupling is comprised
of conical faying surfaces of the non-self-locking type without
axial locking.
[0070] FIG. 10 is a fragmentary view, in longitudinal section, of
the toothbrush of FIG. 9 in a plane turned through 90.degree.
compared to FIG. 9.
[0071] FIG. 11 is a sectional view of the connection between the
attachment brush and the handpiece of the toothbrush of FIGS. 9 and
10 in the region of the detent hooks of the coupling insert.
DETAILED DESCRIPTION
[0072] The toothbrush 1 shown in FIGS. 1 to 3 comprises a handpiece
4 and an attachment in the form of an attachment brush 33. The
handpiece 4 comprises in a manner known in the art a housing in
which a drive motor and a power supply device, for example in the
form of a rechargeable battery, are accommodated and on which an
actuating switch for switching the drive on and off is provided. On
the frontal end of the handpiece 4 shown in FIG. 1, the housing of
the handpiece 4 forms a forward-protruding stub-shaped connecting
member 34 which in the implementation shown is conically shaped and
tapers towards its free end, with the conical contour of the
connecting member 34 having a bevel 35 of more than 7.degree..
Extending from the frontal end of the connecting member 34 is a
drive shaft 31 which is adapted to be driven in an oscillatory
rotational motion.
[0073] The attachment brush 33 comprises a working head 2 with a
set of bristles, not shown in greater detail, which in one
implementation shown is adapted to be driven in an oscillatory
rotational motion about a bristle zone axis pointing approximately
in the bristle longitudinal direction. The working head 2 is
carried by a whole tubular coupling member 3, which can be plugged
onto the neck or the connecting member 34 of the toothbrush
handpiece 4. In the interior of the tubular coupling member 3 of
the attachment brush 33 comprises a plug-on shaft 29 adapted to be
coupled to the drive shaft 31 of the handpiece in a manner
preventing relative rotation.
[0074] To fasten the attachment brush 33 to the handpiece 4 the
tubular coupling member 3 includes a coupling insert 5 in the form
of a coupling sleeve, which is accommodated in the tubular coupling
member 3 for axial displacement in the direction of the attachment
longitudinal direction 38. The inner wall of the coupling member 3
includes an insert mount 16 in which the coupling insert 5 is
seated with a snug fit in its locked condition. The insert mount 16
may be configured in a variety of ways. For example, it may be of
an on the whole cylindrical or on the whole tapered or conical
configuration, or also it may include a cylindrical section as well
as a conical section. The insert mount 16 is on the whole slightly
conical, with a cylindrical section being provided on its region 40
intended for the inner end of the coupling insert 5.
[0075] In a particular implementation, a spring holds the coupling
insert 5 axially in the coupling member 3 or biases it into a
predetermined initial position. The spring may be provided on the
side of the coupling insert 5 close to the working head 2 and be
connected to the coupling insert 5 on the one hand and be fixed to
the coupling member 3 on the other hand.
[0076] The sleeve-shaped coupling insert 5 forms with its inner
circumferential surface a mount 13 which is shaped to conform to
the outer circumferential contour of the connecting member 34 of
the toothbrush handpiece 4 so that the handpiece can be inserted
into the mount 13 with a snug fit. The mount 13 is of an on the
whole conical configuration, with the bevel of the respective taper
adapted to the connecting member 34 and being greater than
7.degree.. The coupling insert 5 has two mutually opposing
engagement sections 6 in the form of resilient coupling or spring
fingers 12 which are integrally made of one piece with the
remaining body of the coupling insert 5 and are separated from the
insert by U-shaped slits so that engagement fingers 12 can spring
open and shut radially in a direction transverse to the attachment
longitudinal direction 38. The engagement fingers 12 extend with
their longitudinal axis substantially parallel to the attachment
longitudinal direction 38.
[0077] As FIG. 1 shows, the engagement fingers 12 carry on their
free ends radially inwardly protruding detent hooks 11 adapted to
snap into conformably shaped detent notches 41 in the outer
circumferential surface of the connecting member 34 of the
toothbrush handpiece 4. Other suitable detent contours may be
provided, for example, a geometrical reversal of the illustrated
implementation comprising detent projections on the connecting
member 34 and detent notches on the engagement fingers 12.
[0078] As FIG. 3 shows, the connecting member 34 and the mount 13
defined by the coupling insert 5 are not circular in cross section
but are both flattened. The connecting member 34 has two mutually
opposing flattened surfaces where the detent notches 41 are
provided. The engagement fingers 12 have their inner sides
complementary to the two flattened surfaces and the detent notches
41 provided therein.
[0079] To be able to release the lock shown in FIG. 1 between the
coupling insert 5 and the connecting member 34 of the toothbrush
handpiece 4, the coupling member 3 of the attachment brush 33
includes an actuating member 7 in the form of a ring which in the
illustrated implementation is seated on the frontal end of the
tubular coupling member 3 on the side remote from the working head
2. The ring may be colored so that the user is able to identify
"his" or "her" attachment brush from the color of the actuating
member 7.
[0080] In a particular implementation, the actuating member 7
comprises two unlocking sections 8, each in the form of an
actuating finger 21 projecting axially in the attachment
longitudinal direction into the interior of the coupling member 3.
These actuating fingers 21 engage in the mount 13 formed by the
coupling insert 5 in the area of the free ends of the engagement
fingers 12. Provided on the projecting ends of the actuating
fingers 21 are beveled surfaces 10 which serve to cooperate with
beveled surfaces on the projecting ends of the engagement fingers
12 of the coupling insert 5. The beveled surfaces 10 are formed
such that during the axial riding motion of the engagement fingers
12 over the actuating fingers 21, the engagement fingers 12 are
spread radially outwardly, whereby they are lifted out of the
detent notches 41 in the connecting member 34 of the toothbrush
handpiece 4.
[0081] In one implementation, the coupling insert 5 is axially
displaceable in the coupling member 3 in order to produce the axial
movement. In some cases, the annular actuating member 7 could be
axially displaceable in the coupling member 3. The actuating member
7 is however securely seated on the coupling member 3 by a catch
mechanism 42 on the inner wall of the coupling member 3.
[0082] As shown in FIG. 2, also the coupling interface between the
plug-on shaft 29 and the drive shaft 31 is lockable by positive
engagement by an engagement part movable in a direction transverse
to the attachment longitudinal direction 38. The engagement part
106 is formed by an engagement finger 112 pivotal about a
transverse axis 140 and having on its inner circumferential surface
a detent projection in the form of a detent hook 111 which
protrudes towards the inside of the mount 43 intended for the drive
shaft 31. The engagement finger 112 is integrally made of one piece
with the body of the plug-on shaft 29. The pivot axle or transverse
axle 140 may be formed by weakening the material at selected
regions. In the implementation shown, the detent hook 111 is
provided in the form of a beveled projection fitting snugly in an
approximately V-shaped notch 131 extending in the drive shaft 31 in
a transverse direction.
[0083] To actuate the engagement finger 112, an actuating part 107
in the form of a pulling hook 132 is provided, which is integrally
made of one piece with the previously described sleeve-shaped
coupling insert 5 and projects from its frontal surface as far as
the area of the drive shaft interface. The pulling hook 132
embraces the end of the engagement finger 112 on the side remote
from the transverse axle 140, and a pair of beveled surfaces 109
and 110 is provided at the overlapping ends of the engagement
finger 112 and the pulling hook 132 so that, while the engagement
finger 112 rides over the pulling hook 132 or vice versa, the axial
relative movement between the two parts is converted into a radial
actuating movement of the engagement finger 112.
[0084] As FIG. 4 shows, the blind-hole-shaped mount 43 in the
plug-on shaft 29 includes two independently active coupling
contours 130a and 130b. The first one 130a of the two coupling
contours is formed by the engagement finger 112 described and an
associated plug-in contour of the mount 43 which generally may have
a cylindrical section 130c. In the implementation shown, a
complementary drive shaft 31 is plugged in whose engagement section
is of an overall cylindrical configuration and whose cross-section
is conveniently not circular cylindrical but has a flattened
surface on one side in order to ensure a corresponding torque
transmission. In this arrangement, the drive shaft 31 is secured to
the plug-on shaft 29 by means of the transversely movable
engagement finger. The second one 130b of the two coupling contours
is axially spaced from the first coupling contour 130a and in the
embodiment shown is arranged in advance of said first coupling
contour 130a as seen looking from the end of the plug-on shaft 29.
In the implementation shown, it is comprised of an overall conical
section of the mount 43 which has a plane beveled surface 130d
inclined relative to the longitudinal axis of the plug-on shaft 29,
advantageously at a bevel of more than 7.degree.. As shown in FIG.
4, the conical second coupling contour extends as far as into the
region of the detent hook 111 so that the second coupling contour
may also be utilized in cooperation with the detent hook 111 of the
engagement finger 112. As shown in FIGS. 2 and 4, however, the
second coupling contour 130b is not utilized because the drive
shaft 31 of the toothbrush handpiece 4 is cylindrically shaped in
the described manner.
[0085] Consequently, the following mode of operation results:
[0086] In a particular application, while the attachment brush 33
is being plugged onto the toothbrush handpiece 4, the connecting
member 34 threads into the mount 13 of the coupling insert 5,
whereby the detent hooks 11 slides along the outer circumferential
surface of the connecting member 34 as the engagement fingers 12
spread open. Upon the fully plugged-on position being reached, the
engagement fingers 12 spring radially inwardly causing the detent
hooks 11 to engage the detent notches 41 with a snap action. The
coupling insert 5 forms a spring catch which upon being plugged
onto the toothbrush handpiece 4 locks automatically to the
handpiece. In the locked position the connecting member 34 sits in
the conical mount 13 with a snug fit. Similarly, the coupling
insert 5 is snugly received in the insert mount 16 of the coupling
member 3.
[0087] To release the positive-engagement lock the user simply
needs to pull the attachment brush 33 in the attachment
longitudinal direction 38 off the toothbrush handpiece 4. This
results first in an axial relative movement between the coupling
member 3 and the coupling insert 5 because the latter is held by
the detent hooks 11 axially securely on the toothbrush handpiece 4.
As the result of such axial relative movement the actuating fingers
21 of the actuating member 7 move under the engagement fingers 12
or the detent hooks 11 so that the engagement fingers 12 are lifted
by way of the pair of beveled surfaces 9 and 10 radially out of the
detent notches 41. During the axial relative movement between the
coupling insert 5 and the coupling member 3, a corresponding
deformation of the spring sections 18 and 19 of the spring 17
occurs.
[0088] When the engagement fingers 12 with their detent hooks 11
are unlocked from the toothbrush handpiece 4, the coupling insert 5
is pulled together with the coupling member 3 off the handpiece 4.
In some implementations, a spring 17 operates to return the
coupling insert 5 to its initial position. Due to the conical
configuration of the mount 13 and/or a possibly provided follower
element, the coupling insert 5 would be pushed back into its
locking position when plugged again onto the toothbrush handpiece 4
even in the absence of the spring 17.
[0089] At the same time, the axial movement of the coupling insert
5 or of the pulling hook 132 formed thereon causes the lock between
the plug-on shaft 29 and the drive shaft 31 to be released. By way
of the pair of beveled surfaces 109 and 110, the axial movement of
the pulling hook 132 relative to the engagement finger 112 pulls
the latter radially outwardly, causing it to be unseated from the
notch 131 in the drive shaft 31. The drive shaft 31 can thus be
pulled off the plug-on shaft 29.
[0090] An alternative implementation of the drive shaft interface
and its locking engagement is shown in FIG. 5. The engagement part
of the plug-on shaft 29 which affects the locking engagement is
provided in the form of a pivotal engagement finger 112 having an
inwardly protruding detent hook 111, where the engagement finger
112 forms a pivotal latch or a pawl. In this arrangement, the
engagement finger 112 is formed as a part separate from the
remaining body of the plug-on shaft 29 and arranged in an axially
extending recess 106 in the area of the mount 43, so that the
detent hook 111 projects inwardly into the mount 43. The
transversely extending pivot axle 140 may be formed by an axle pin,
for example.
[0091] In the implementation shown in FIG. 5, the engagement finger
112 is actuated by a function arm 135 protruding axially from the
coupling insert 5 and forming the actuating part 107. In
particular, for actuating the pivotal engagement finger 112
cam-type beveled surfaces 109 and 110 are provided at the front end
of the function arm 135 and the engagement finger 112, with the
beveled surface 109 on the engagement finger 112 having a lever arm
in relation to the finger's pivot axle 140 and in the
implementation shown is arranged between said pivot axle 140 and
the detent hook 111.
[0092] Another variant of the engagement part 106 is shown in FIG.
6, according to which the engagement part 106 is formed by a
pivotal pawl 136 which extends transversely across and beyond the
mount 43 in the plug-on shaft 29. Similar to the previously
described implementations, the detent pawl 136 also has a detent
hook 111 for engagement in the notch 131 of the drive shaft 31. In
the implementation of FIG. 6, however, the detent pawl 136 is
mounted on the plug-on shaft 29 on the opposite side of the detent
hook 111 about a pivot axle 140 which equally extends in a
transverse direction. A spring device 137 biases the detent pawl
136 into its locking position, and the spring device 137 may be
formed by a spring arm integrally formed on the plug-on shaft
29.
[0093] To actuate the detent pawl 136, an actuating part 107 in the
form of a pulling hook 132 is provided which protrudes from the
coupling insert 5 axially as far as the area of the drive shaft
interface. Similar to the implementation of FIGS. 1 to 4, actuation
of the detent pawl 136 is effected by way of a pair of beveled
surfaces 109 and 110.
[0094] FIG. 7 shows an implementation of the locking mechanism
between the two shafts 29 and 31 similar to FIG. 6. The detent pawl
136 extends transversely across and beyond the mount 43 in the
plug-on shaft 29, but in contrast to the implementation of FIG. 6,
the transversely extending pivot axle 140 and the detent hook 111
are arranged on the same side of the drive shaft 31. The section
136a of the detent pawl 136 extending to the opposite side of the
mount 43 forms an actuating arm which is actuatable by the pulling
hook 132 by way of a pair of beveled surfaces 109 110 similar to
the previously described implementation.
[0095] Another implementation of the locking mechanism between the
plug-on shaft 9 and the drive shaft 31 is shown in FIG. 8.
According to this embodiment, the plug-on shaft 29 includes an
engagement part 106 in the form of a detent ring 125 which can be
radially widened and narrowed, which can be of a longitudinally
slotted configuration, for example, to enable its widening.
Advantageously, the detent ring 125 may be configured to be
elastically biased into its locking, narrowed position. As FIG. 8
shows, the detent ring 125 has on its inner circumferential surface
an inwardly protruding detent contour in the form of a detent hook
111 which engages in a notch 131 in the drive shaft 31.
[0096] In this arrangement, the detent ring 125 is seated in a
circumferential recess on the body of the plug-on shaft 29. In the
region of said detent hook 111 the detent ring 125 has on its outer
circumferential surface an engagement notch which cooperates with
the pulling hook 132 which in turn is integrally formed on the
coupling insert 5 in axially protruding manner. Again, a pair of
beveled surfaces 109 and 110 may be provided on the detent ring 125
and the pulling hook 132. For the better support, an expansion
chamfer may be provided on the recess in the outer circumferential
surface of the plug-on shaft 29 and/or on the abutting front edge
of the detent ring 125, so that an axial movement of the detent
ring 125 relative to the body of the plug-on shaft 29 by means of
the pulling hook 132 produces an expanding movement.
[0097] The mode of operation of the locking engagement of the drive
shaft interface is similar to the previously described
embodiments.
[0098] FIGS. 9 to 11 show a particular implementation which is
generally similar to the implementation of FIGS. 1 to 3. A
significant difference lies in the construction of the coupling
interface in the drive train. As is shown in FIG. 10, the plug-on
shaft 29 of the attachment brush 33 is coupled to the drive shaft
31 of the handpiece by conical faying surfaces, the drive shaft 31
being conically shaped on its end protruding from the housing of
the handpiece 4, and a bevel being equally allowed to be greater
than 7.degree.. The plug-on shaft 29 has a conformably shaped,
frontally open, advantageously blind-hole type mount 43 which
comprises a faying surface 130c which is adapted to the taper of
the drive shaft 31 and likewise has a bevel of more than 7.degree..
By firmly plugging on the attachment brush 33, a connection by
positive and/or frictional engagement can be established between
the plug-on shaft 29 and the drive shaft 31. This connection
between the shafts may be free of axially effective snap-action
connections or other axial holding means.
[0099] To make sure that only one of the two coupling contours 130a
and 130b of the plug-on shaft 29 is used, for example, to ensure
that a user can only use "his" or "her" attachment brush or
toothbrush, it is possible for one of the two coupling contours
130a and 130b to be covered by non-releasable insertion of an
adapter. For example, an adapter could be non-releasably inserted
into the mount 43 of the plug-on shaft 29, which adapter closes the
first coupling contour 130a so that the second conical coupling
contour 130b is left for use. Alternatively or in addition, such an
adapter could also be provided on the handpiece, in particular by
plugging it onto the drive shaft 31 of the toothbrush handpiece 4.
For example, a conical adapter could be slipped onto the drive
shaft 31 shown in FIG. 4 by way of example and be non-releasably
snapped into the notch 131 there, so as to enable a coupling to be
effected with the conical second coupling contour 130b.
* * * * *