CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national phase application under 35 U.S.C. § 371 of PCT International Application No. PCT/EP2006/011967, filed Dec. 13, 2006, which claims priority to German Application No. 10 2005 061 1491.4, filed Dec. 22, 2005. The contents of each of these applications are incorporated herein by reference in their entirety.
This invention relates to a preferably electric toothbrush having a handpiece and a detachable toothbrush head.
From DE 197 29 516 there is known a manual toothbrush in which toothpaste can be supplied from a reservoir in the handpiece to a set of bristles on the toothbrush head through a conduit provided in the interior of a detachable toothbrush head. In electric toothbrushes the space available in the toothbrush head is very limited since it serves at the same time to accommodate the drive train for transmitting the drive motion to the brush head. The toothpaste conduit and in particular its associated conduit coupling have to be built to very small dimensions to enable them to be accommodated in the toothbrush head. In addition, the brush heads of electric toothbrushes are exchanged frequently, for example, when a handpiece has several users, where each user plugs his or her attachment brush onto the handpiece and removes it again. Any toothpaste remaining in the detached toothbrush head, meaning in the conduit provided thereon, may dry up, resulting in a clogged conduit.
In one aspect, a toothbrush head of a toothbrush has a set of bristles and a coupling device for coupling it to a handpiece of the toothbrush. The toothbrush head includes a conduit for supplying a pasty, gel-type and/or liquid substance to be applied, in particular toothpaste. The coupling device has a conduit coupling for coupling the conduit to a conduit section on the handpiece side.
Another aspect features the handpiece of such a toothbrush with a coupling device for coupling the toothbrush head thereto. The handpiece includes a conduit for supplying a pasty, gel-type and/or liquid substance to be applied, in particular toothpaste. The coupling device has a conduit coupling for coupling the conduit on the handpiece side to the conduit on the brush head side.
In some implementations, the conduit coupling connects the conduit on the handpiece side with the conduit on the brush head side for supplying the substance to be applied in such a way that the conduit cross-section is automatically closed when the toothbrush head is disengaged from the handpiece and is automatically opened on re-engagement. In some implementations, the conduit coupling comprises a control valve which opens automatically by engagement of a valve actuator when the brush head is coupled to the handpiece of the toothbrush. The control valve connects a conduit section on the handpiece side with a conduit section on the brush head side, and closes the conduit automatically on decoupling from the handpiece. In this arrangement, the control valve may be generally provided either on the toothbrush head or on the handpiece, with the valve actuator being arranged on the respective other toothbrush portion. A control valve arranged on the toothbrush head is opened by a valve actuator provided on the handpiece, while a control valve arranged on the handpiece is opened by a valve actuator provided on the toothbrush head.
The valve actuator function may be performed in particular by the respective conduit end to be connected. When the control valve is brought into engagement with the conduit section to be coupled on coupling of the toothbrush head to the handpiece, the control valve is opened.
In some implementations, the control valve may include an elastic valve opener which is elastically deformable and actuatable by the conduit end to be coupled. When the control valve or its elastic valve opener portion is brought into engagement with the end portion of the conduit to be coupled on coupling the toothbrush head to the handpiece, the valve opener deforms elastically, thereby opening the valve. Conversely, when the toothbrush head is detached from the handpiece of the toothbrush, thereby causing the coupled conduit end to become disengaged from the valve opener, the latter returns, on account of its elasticity, automatically to its initial position, whereby the valve becomes closed again.
Advantageously, the valve opener forms at the same time a coupling section through which the conduit section to be coupled is adapted to be brought into fluid communication with the conduit section connected with the control valve in fluid or medium-tight manner. This lends the valve opener a dual function. On the one hand, it serves to open the control valve during coupling and decoupling. On the other hand, it ensures the fluid-tight connection with the conduit to be coupled.
The valve opener may in particular form a neck which is adapted to be slid onto the end of the conduit to be coupled when the toothbrush head is coupled to the handpiece. In this arrangement, the inside diameter of the neck is advantageously smaller than the outside diameter of the conduit end to be inserted, which causes the neck to expand radially when it is slid onto the conduit end to be coupled. This elastic expanding motion is translated by the control valve into an opening motion of the valve cross-section.
In order to accomplish accurate opening and closing of the valve, provision may be made for at least one sealing lip which forms the bottom of the above-mentioned neck and is connected therewith, so that it opens on expansion of the neck and closes the valve passageway again on contraction of the neck. In this arrangement, said sealing lip is in particular integrally formed on the peripheral inner wall of the neck and protrudes therefrom inwardly into the interior of the valve passageway, so that it can move through the valve on expansion of the neck in a direction transverse to the direction of flow.
According to a particularly advantageous embodiment, said sealing lip for opening and closing the valve passageway may be formed by an elastic cross bar or an elastic partition wall which sits in the valve passageway of the control valve and is connected with the valve passageway wall annularly circumferentially and includes preferably approximately centrally a preferably approximately slot-shaped valve opening whose edges form sealing lips sitting fluid-tight one on top of the other or side-by-side in the non-open state of the control valve. When said neck and hence the valve passageway are expanded, the elastic partition wall is pulled apart radially on its edges because of its connection with the wall of the valve passageway, as a result of which the valve lips move apart, causing the slot-shaped valve opening to open and become larger.
In order to make opening of the sealing lips easier, the cross-section of the valve body may be tapered in the area of the partition wall. In particular, the control valve may have on its outer periphery in the area of the partition wall a constriction which facilitates the expansion of the neck adjoining the constriction and hence the pulling apart of the sealing lips. In addition, the expansion of the neck is, so to speak, decoupled from the valve section arranged on the opposite side of the sealing lips, that is, only the neck with the sealing lips connected therewith is expanded, whilst the remaining part of the valve is not expanded or at least only insignificantly.
The control valve may be fixedly connected with the section of the conduit to which the control valve is assigned by a connecting section. In this arrangement, the connecting section of the control valve may be configured in such a way that it can be plugged onto or into the corresponding conduit. Advantageously, the connecting section has a circumferential bead seal enabling a fluid-tight sealing of the control valve relative to the respective conduit or the wall sections bounding said valve.
The control valve may be built to comprise several parts and include components made of various materials. In some implementations, however, the control valve is formed as a one-piece construction and is comprised of a fully elastic valve body of soft plastics, where applicable, also of rubber or a rubber-like material.
The toothbrush, including the toothbrush head and the handpiece, provides a simple, small-size conduit coupling which inhibits toothpaste in the conduit from drying up.
BRIEF DESCRIPTION OF THE DRAWINGS
Features described herein will be explained in the following with reference to an embodiment for an electric toothbrush illustrated in the accompanying drawings.
FIG. 1 is an overall perspective view of an electric toothbrush having a conduit for the supply of toothpaste to the toothbrush head;
FIG. 2 is a perspective sectional view of a control valve in closed condition; and
FIG. 3 is a perspective sectional view of the control valve of FIG. 2 in open condition.
The toothbrush shown in FIG. 1 comprises a handpiece 1 and a toothbrush head 2 which sits on a brush tube 3 forming a frontal end of the handpiece 1 or being connected therewith. The handpiece 1 is formed by a toothbrush housing 4 which accommodates single-use or rechargeable batteries and a drive motor which can be switched on and off by means of a switch 6 arranged on the outside surface of the housing 4. Further received in the handpiece 1 is a toothpaste reservoir from which a supply of toothpaste can be fed to the brush head 2 through a conduit 7 a provided inside the brush tube 3, either by manual means or by motor means, for example, by a pump driven by the drive motor 5.
The toothbrush head 2 has a drivable set of bristles 9 which is adapted to be driven by the drive motor in an oscillatory rotational motion through a drive train, not shown in greater detail, which is received in the interior of the brush tube 3.
As FIG. 1 shows, the toothbrush head 2 can be detached from the handpiece 1 at a parting line 8. The detachable connection between the toothbrush head 2 and the handpiece 1 is accomplished by a coupling device 10. The parting line 8 may also be provided between the brush tube 3 and the toothbrush housing 4, i.e., the brush tube 3 and the toothbrush head 2 may be integrally made of one piece.
The conduit 7 for supplying the toothpaste continues beyond the parting line 8, with a fluid or conduit coupling 11 being inserted in the conduit 7, which coupling is part of the coupling device 10 and couples the section 7 a of the conduit 7 on the handpiece side to the section 7 b of the conduit 7 on the brush head side when the toothbrush head 2 is attached to the handpiece 1, while enabling on the other hand the two conduit sections 7 a and 7 b to be separated from each other when the toothbrush head 2 is detached.
In this configuration, the conduit coupling 11 comprises the control valve 12 shown in FIGS. 2 and 3, which in the embodiment shown is fixedly connected with the section 7 b of the conduit 7 on the brush head side and is detachably connectible with the section 7 a of the conduit 7 on the handpiece side. It will be understood, however, that such a control valve 12 may also be mounted on the section 7 a of the conduit 7 on the handpiece side.
The control valve 12 is comprised of a single-piece, fully elastic valve body 13 which in the embodiment shown is constructed to be essentially rotationally symmetrical about a valve longitudinal axis 14. As FIGS. 2 and 3 show, formed in the valve body 13 is a valve passageway 15 which may be closed and opened by an equally elastic control member 17. Serving as control member 17 is a diaphragm, meaning an elastic transverse wall 18 of an essentially disk- or plate-shaped configuration which extends substantially radially. The transverse wall 18 is integrally formed on the inner wall of the valve passageway 15 in an annular circumferential fashion, forming, so to speak, a partition wall which divides the valve passageway 15 into the valve passageway sections 15 a and 15 b lying coaxially one behind the other.
Provided in the transverse wall 18 is a slot-shaped valve passageway opening 19 so that the adjoining sections of the transverse wall 18 form sealing lips 16 which, in the closed condition of the valve according to FIG. 2, rest against one another, thereby closing the valve passageway opening 19.
As FIG. 2 shows, the valve body 13 has in the area of the sealing lips 16 on its outer circumference a constriction 20 where the outside diameter of the valve body 13 is reduced and the wall thickness of the valve body 13 is also reduced relative to the axially adjoining sections. This makes it easier for the sealing lips 16 to open.
The entire valve body 13 in the area of the valve passageway section 15 a is radially expansible. The valve passageway section 15 a forms a neck into which the conduit section 7 a on the handpiece side is insertable. In this arrangement, the inside diameter of the approximately cylindrical valve body section 13 a, which surrounds and defines said valve passageway section 15 a, is constructed to be somewhat smaller than the outside diameter of the conduit section 7 a to be inserted into the valve passageway section 15 a. When the toothbrush head 2 is attached to the handpiece 1 by means of the coupling device 10, the conduit section 7 a is inserted into the undersize valve passageway section 15 a, causing the valve body section 13 a to expand, as shown in FIG. 3. The expansion of the valve body section 13 a also pulls the partition wall 18 radially apart, whereby the sealing lips 16 open and the valve passageway opening 19 between the sealing lips 16 is formed, as shown in FIG. 3.
Insofar, said valve body section 13 a forms the valve opener by means of which the control valve 12, more accurately speaking, its elastic sealing lips 16 can be opened. At the same time, said valve body section 13 a forms a coupling section by means of which the control valve 12 is detachably connectible with the conduit section 7 a to be coupled.
As FIGS. 2 and 3 show, said valve body section 13 a extends in the embodiment shown from the constriction 20 to the one end of the valve body 13 and is of an essentially cylindrical configuration, with a flange-shaped, radial edge rib being formed at the frontal end of the valve body section 13 a, which rib may serve as seal.
The opposite valve passageway section 15 b lying on the other side of the sealing lips 16 is likewise embraced by an essentially cylindrical valve body section 13 b which also has at its frontal end a radially outwardly directed bead seal 22. In this configuration, the valve body section 13 b serves to connect the control valve 12 with the conduit section 7 b on the brush head side on which the control valve 12 may be mounted.
Owing to the freely selectable geometry of the valve body 13, in particular of its valve body sections 13 a and 13 b, it is possible to accomplish an optimal sealing function relative to the brush tube 3 and the brush head 2, respectively. The actual switching function of the valve lies in the area of the sealing lips 16 and the diameter of the neck 15 a. When the toothbrush head 2 is coupled to the handpiece 1, the conduit section 7 a on the handpiece side is introduced into said neck 15 a, causing the sealing lips 16 to open and enabling the application substance, in particular the toothpaste, to flow through unhindered. Conversely, when the toothbrush head 2 is detached from the handpiece 1, said conduit section 7 a is retracted from the neck 15 a, causing the sealing lips 16 to close and preventing the toothpaste from drying out.