Attachment for oral care device handle

Abstract

To provide an oral care device attachment coupled to an oral care device handle having a cylindrical drive shaft coupling end portions.SOLUTION: An attachment includes: an external attachment tube having a coupling end portion designed to be fixed to a housing of an oral care device handle to be attachable / detachable; a carrier attached to the external attachment tube for drive motion; and a motion transmission part arranged inside the external attachment tube. The motion transmission part includes: a first end portion coupled to the carrier; and a second end portion provided to be coupled to a cylindrical drive shaft coupling end portion. The second end portion has a connection unit including an upper plate and one elastic or flexible wall element extending from the upper plate.SELECTED DRAWING: Figure 7A

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to an oral care device attachment for coupling to a drive shaft of an oral care device handle having an essentially cylindrical drive shaft coupling end. [Background technology]

[0002] It is known that a drive shaft of an oral care device handle, such as an electric toothbrush, can be coupled by magnetic attraction to a motion transmission unit disposed within an oral care device attachment, such as a replacement brush head, particularly when the drive shaft provides linear vibration. The motion transmission unit may be coupled to a carrier attached to the outer tubular housing of the attachment so that, when the linear vibration of the drive shaft is transmitted to the carrier by the motion transmission unit, the carrier is driven into oscillatory rotation about the rotation axis. Such magnetic coupling avoids wear-prone mechanical coupling components and serves to transmit linear vibration with low noise, as magnetic attraction holds the coupling partners together. Because the magnetic coupling partners only need to connect on an axial surface, for example, the distance between the drive shaft coupling end and the oral care device handle housing can be relatively small, e.g., with a circumferential distance or gap of less than 1 mm, which reduces the overall coupling area compared to other designs. Such a coupling concept is described, for example, in European Patent No. 2550938(B1).

[0003] However, magnetic coupling requires, for example, a magnet located at the coupling end of the drive shaft of the oral care device handle and additional magnets or magnetizable elements at each coupling end of the motion transmission part located within the attachment, which components make the coupling relatively expensive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent No. 2550938(B1) Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, there is a need to provide a less expensive connection between the essentially cylindrical connection end of the drive shaft of the oral care device handle and the motion transmission part of the oral care device attachment for the oral care device handle, which still allows for a small circumferential gap between the connection end of the drive shaft and the housing of the oral care device handle. [Means for solving the problem]

[0006] According to at least one aspect, an oral care device attachment for coupling to an oral care device handle having an essentially cylindrical drive shaft coupling end is provided, the attachment comprising: an outer attachment tube having a coupling end intended to be removably fixed to a housing of the oral care device handle; a carrier attached to the outer attachment tube for driving movement; and a motion transmission part arranged inside the outer attachment tube, the motion transmission part having a first end coupled to the carrier and a second end arranged to couple to the essentially cylindrical drive shaft coupling end, the second end having a coupling unit each having an upper plate and at least one at least partially deformable essentially cylindrical wall element extending from the upper plate, or at least two elastic or flexible wall elements extending from the upper plate, each elastic or flexible wall element extending over a portion of an imaginary receiver cylinder such that an essentially cylindrical receiver receptacle is defined by the upper plate and one at least partially deformable essentially cylindrical wall element, or by the upper plate and at least two elastic or flexible wall elements.

[0007] According to at least one embodiment, an oral care device attachment configured to be coupled to a drive shaft of an oral care device handle having an essentially cylindrical drive shaft coupling end is provided, the attachment comprising: an outer attachment tube having a coupling end intended to be fixed to the oral care device handle; a carrier attached to the outer attachment tube for driving movement; and a motion transmission part arranged inside the outer attachment tube, the motion transmission part having a first end coupled to the carrier and a second end configured to be coupled to the essentially cylindrical drive shaft coupling end, the second end comprising a coupling unit having an upper plate; and a spring arranged between the outer attachment tube and the motion transmission part, which biases the motion transmission part toward the coupling end of the outer attachment tube. [Brief explanation of the drawings]

[0008] The present disclosure will be further clarified by reference to the detailed description of the exemplary embodiments and drawings. [Figure 1] FIG. 1 is a diagram of an oral care device embodied as an electric toothbrush. [Figure 2] 1 is a diagram of a replaceable oral care attachment for an oral care device, where the attachment is realized as a toothbrush head. [Figure 3] FIG. 1 is a cross-sectional view through the connection between an oral care handle and an interchangeable oral care attachment, as known from the prior art. [Figure 4A] 1 is a cross-sectional view of a first example of an oral care device attachment proposed in the present disclosure. [Figure 4B] 10A and 10B are diagrams showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a first example; [Figure 4C] 4B is a cross-sectional view through the attachment shown in FIG. 4A with the motion transmission member coupled to the drive shaft of the oral care device handle. [Figure 4D]4B is a perspective view of the parts of the attachment shown in FIG. 4A, also showing the mechanical connectors omitted in FIG. 4A, showing only the outer attachment tube. [Figure 5A] FIG. 1 is a cross-sectional view of a second example of an oral care device attachment as proposed in the present disclosure. [Figure 5B] FIG. 10 shows a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a second example. [Figure 6A] FIG. 10 is a cross-sectional view of a third example of an oral care device attachment as proposed in the present disclosure. [Figure 6B] 10A and 10B are diagrams showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a third example; [Figure 7A] FIG. 10 is a cross-sectional view of a fourth example of an oral care device attachment proposed in the present disclosure. [Figure 7B] FIG. 10 is a diagram showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a fourth example. [Figure 8A] FIG. 10 is a cross-sectional view of a fifth example of an oral care device attachment as proposed in the present disclosure. [Figure 8B] FIG. 10 is a diagram showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a fifth example. [Figure 9A] FIG. 10 is a cross-sectional view of a sixth example of an oral care device attachment proposed in the present disclosure. [Figure 9B] FIG. 10 is a diagram showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a sixth example. [Figure 10A] FIG. 10 is a cross-sectional view of a seventh example of an oral care device attachment proposed in the present disclosure. [Figure 10B] FIG. 13 is a diagram showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a seventh example. [Figure 11A] FIG. 10 is a cross-sectional view of an eighth example of an oral care device attachment proposed in the present disclosure. [Figure 11B] FIG. 13 is a diagram showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to an eighth example. [Figure 12A] FIG. 10 is a cross-sectional view of a ninth example of an oral care device attachment as proposed in the present disclosure. [Figure 12B] FIG. 13 is a diagram showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a ninth example. [Figure 13A] FIG. 14 is a cross-sectional view of a tenth example of an oral care device attachment proposed in the present disclosure. [Figure 13B] FIG. 19 is a diagram showing a part of a motion transmission part and a coupling unit provided at a second end of the motion transmission part according to a tenth example. [Figure 14] FIG. 1 is a perspective view of the upper end of an oral care handle including an essentially cylindrical drive shaft coupling end and a drive shaft housing. DETAILED DESCRIPTION OF THE INVENTION

[0009] According to the present disclosure, a solution is proposed for coupling an oral care device attachment to an oral care device handle having a drive shaft with an essentially cylindrical drive shaft coupling end. The drive shaft is arranged to provide linear oscillation, i.e., oscillatory motion of the drive shaft along its longitudinal axis. The essentially cylindrical drive shaft coupling end may have (a) a diameter in the range of 4 mm to 8 mm, preferably about 6 mm, such as 6.2 mm; (b) a relatively small circumferential distance to a portion of the handle housing surrounding the essentially cylindrical drive shaft coupling end, where the circumferential gap or distance may be less than about 1 mm, preferably less than about 0.8 mm, and more preferably about 0.6 mm; and / or (b) at least one recess, circumferential groove, or may continue at a smaller diameter. The circumferential direction may not be constant, i.e., the housing surrounding the essentially cylindrical drive shaft coupling end may have a non-circular cross section or may be arranged non-coaxially with respect to the essentially cylindrical drive shaft coupling end. This may mean that the circumferential gap has a gap width of, for example, about 0.6 mm in at least one region and a gap width of, for example, 1.0 mm in another region. The gap width is understood to be measured in a plane perpendicular to the longitudinal axis of the essentially cylindrical drive shaft coupling end. Furthermore, the essentially cylindrical drive shaft coupling end may have a length extension in the direction of the longitudinal axis of between 4 mm and 20 mm, preferably between 8 mm and 16 mm, and more preferably about 14 mm, such as 13.8 mm.

[0010] FIG. 1 is a diagram of an exemplary oral care device 1 comprising an oral care device attachment 10 (also referred to herein simply as the “attachment”) and an oral care device handle 20 (also referred to herein simply as the “handle”). Attachment 10 comprises an outer attachment tube or housing 11 and a carrier 12 attached to outer attachment tube 11 for driven oscillating rotation as indicated by double arrow R (although attachments proposed herein are not limited to having carriers driven in oscillating rotation). Here, oral care elements 13 are attached to carrier 12. The handle comprises a housing 21. Attachment 10 is removably attached to handle 20; preferably, outer attachment tube 11 is mechanically fixed to housing 21 of handle 20, such that, in the attached state, outer attachment tube 11 and housing 21 do not move relative to each other. As will be explained in more detail, the drive shaft of the handle 20 is removably connected to a motion transmission part disposed within the outer attachment tube 11 such that motion provided by the drive shaft (typically linear vibration along its longitudinal direction) is transmitted by the motion transmission part to the carrier 12 during operation. The oral care device 1 is shown here as an electric toothbrush, the attachment 10 as a replaceable brush head, and the oral care elements 13 as bristle tufts.

[0011] 2 is a view of an exemplary attachment 10A shown in isolation. The attachment 10A comprises an outer attachment tube or housing 11A, a carrier 12A attached to the outer attachment tube 11A for drive movement, and a plurality of oral care elements 13A attached to the carrier 12A.

[0012] FIG. 3 is a cross-sectional view through the top of an oral care device 1B including an attachment 10B removably attached to a handle 20B (only partially shown) having a housing 21B, which is only shown here. The attachment 10B and handle 20B generally extend along a longitudinal axis L, which here coincides with the central axis of the drive shaft 31B of the handle 20B. The cross-sectional view shows an oral care device 1B as generally described, for example, in EP 2550940 B1. In the oral care device 1B, a motion transmission part 13B is coupled at a first end to a carrier 12B, which carries a plurality of oral care elements 13B and is mounted to an outer attachment tube 11B of the attachment 10B for driven rotation about an axis 15B, i.e., about the axis of rotation defined by the axis 15B. The motion transmission part 13B comprises a first magnetic interaction element 14B at a second end and is releasably coupled to an essentially cylindrical drive shaft coupling end 30B. The essentially cylindrical drive shaft coupling end 30B includes a second magnetic interaction element 32B that magnetically interacts with the first magnetic interaction element 14B, such that both magnetic interaction elements 14B and 32B remain essentially in contact during normal operation when the drive shaft 31B provides linear reciprocating motion along the longitudinal axis L. The magnetic interaction is established by each of the magnetic interaction elements 14B and 32B being realized as a magnet, or by one of them being realized as a magnet and the other as a magnetizable element. The first magnetic interaction element 14B is fixed to the second end of the motion transmission portion 13B, and the second magnetic interaction element 32B is part of the essentially cylindrical drive shaft coupling end 30B. Because the attachment 10B may typically be intended to be a disposable part, it may be preferable to realize the second magnetic interaction element 32B as a magnet and the first magnetic interaction element 14B as a magnetizable element.The essentially cylindrical drive shaft coupling end 30B is realized here by a cap 34B, e.g., a metal cap. A second magnetic interaction element 32B, which may be a cylindrical magnet, e.g., a cylindrical NdFeB-type magnet, is fixed to the cap 34B by adhesive 33B on the one hand and to the drive shaft 31B by adhesive 33B on the other hand. The essentially cylindrical drive shaft coupling end 30B has a diameter d and a length 1, as shown in FIG. 3 . Possible values ​​of the diameter d and the length 1 are described in the previous paragraph. Since the drive shaft 31B may have a smaller diameter than the essentially cylindrical drive shaft coupling end 30B, an undercut may be provided below the essentially cylindrical drive shaft coupling end 30B, i.e., at the lower end facing the handle 20B. Therefore, the term “undercut” in this application refers to a portion below the essentially cylindrical drive shaft coupling end that has a smaller diameter than the essentially cylindrical drive shaft coupling end itself, whether in all directions or only in one or several circumferentially distributed regions. The attachment 10B here includes a mating end with a first mechanical connector 16B that detachably couples with a second mechanical connector 26B of the handle 20B, thereby positionally securing the outer attachment tube 11B and the drive shaft housing 22B relative to one another. The first and second mechanical connectors 16B and 26B may be mechanically coupled to one another by a mechanical coupling element, such as a flexible snap hook, as is commonly known in the art. The drive shaft 31B may be sealed to the hollow portion of the drive shaft housing 22B by a seal 35B, such that liquids cannot enter the hollow portion.

[0013] Ten exemplary embodiments of an oral care device attachment according to the present disclosure are described below. All exemplary attachments except the tenth exemplary attachment comprise a coupling unit having a top plate and either (a) one at least partially deformable, essentially cylindrical wall element that, together with the top plate, defines a receiver cylinder suitable for receiving an essentially cylindrical drive shaft coupling end of a drive shaft from an oral care device handle, or (b) at least two elastic, flexible, or pivotable wall elements that define an essentially cylindrical receiver volume or receptacle for receiving the essentially cylindrical drive shaft coupling end. There are at least three additional aspects considered in the exemplary embodiments, which can be implemented individually or together, i.e., two of the three aspects together, or all three aspects together. These three additional aspects are as follows: (1) A spring disposed between the outer attachment tube and the motion transmission part, such that the second end of the motion transmission part including the coupling unit is biased towards the coupling end of the attachment, in other words, in the attached state and during the attachment process, it is biased against the essentially cylindrical drive shaft coupling end. (2) A separable mechanical connection between the coupling unit and the remainder of the motion transmission section, such that the coupling unit can be considered an adapter that can be attached to an essentially cylindrical drive shaft coupling end and remain there when the remainder of the attachment is removed. (3) At least one protrusion provided on the deformable, essentially cylindrical wall element or on at least one of the at least two elastic, flexible or pivotable wall elements, the protrusion being suitable for interacting with a receptacle or undercut of the essentially cylindrical drive shaft coupling end.

[0014] Possible material choices for realizing at least one at least partially deformable essentially cylindrical wall element from a thermoplastic elastomer or natural rubber include, but are not limited to, one of the following materials: thermoplastic elastomer (TPE), nitrile rubber (NBR), silicone rubber, EPDM rubber, styrene-butadiene rubber (SBR).

[0015] Possible material choices for realizing the at least partially deformable essentially cylindrical wall element or the at least two elastic or flexible wall elements from a thermoplastic material include, but are not limited to, one of the following materials: polypropylene (PP), polyamide (PA), polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), thermoplastic elastomers (TPE) such as Hytrel, or polybutylene terephthalate (PBT). If the top plate or part thereof is made from a thermoplastic material, the same material can be chosen to realize the top plate.

[0016] Possible material choices for realizing the at least partially deformable, essentially cylindrical wall element or at least two elastic or flexible wall elements from sheet metal include, but are not limited to, one of the following materials: stainless steels, for example, with material numbers 1.4301, 1.4303, 1.4305, 1.4306, 1.4307, and 1.4310 according to standard EN 10027-2, as well as other non-corrosive steels or other metals suitable for producing thin foils with good elastic properties, preferably classified as food-grade materials. Other metallic materials, such as molybdenum, titanium, or alloys, can also be used, but tend to be more expensive. If the top plate or part of it is made from metal, the same material can be selected to realize the top plate.

[0017] 4A-4D are diagrams of a first example of an attachment 100 proposed herein. Fig. 4A is a cross-sectional view of attachment 100, Fig. 4B is a perspective detail view showing the second end of motion transmission portion 140 including coupling unit 200, Fig. 4C is a cross-sectional view of the lower portion of attachment 100 and drive shaft 22 including essentially cylindrical drive shaft coupling end 30, and Fig. 4D is a partially transparent perspective view of attachment 100' further including first mechanical connector 300, which is omitted in Fig. 4A. Identical features of attachment 100 or 100' have the same reference numerals.

[0018] The attachment 100 shown in FIG. 4A includes an outer attachment tube 110 and a motion transmission unit 140 disposed within the hollow portion of the outer attachment tube 110. The motion transmission unit 140 has a first end coupled to a carrier 120 that carries an oral cleaning element 130 and is disposed for driving motion relative to the outer attachment tube 110. The attachment 100 has a lower end including an opening 111 for coupling the attachment 100 to a handle of an oral care device. Specifically, the drive shaft of the handle enters the hollow portion through the opening 111 and establishes a connection with the second end or coupling end of the motion transmission unit 140, the coupling end of which includes a coupling unit 200. The coupling unit 200 includes an upper plate 210 and an at least partially deformable, essentially cylindrical wall element 220 that defines an imaginary receiver cylinder 251 for receiving the essentially cylindrical drive shaft coupling end of the drive shaft of the handle of the oral care device (see FIG. 4C). The lower end of the attachment 100 typically includes a first mechanical connector 300, which is omitted from Figures 4A and 4C but is shown in Figure 4D.

[0019] FIG. 4B shows the lower portion of the motion transfer part 140, where "lower" refers to the second end of the motion transfer part 140, which comprises the coupling unit 200. The motion transfer part 140 has a first part 141 extending toward the first end, which is coupled to the carrier 120 (see FIG. 4A), and a second part 143 continuing to the coupling unit 200. A pivot 142 is provided between the first part 141 and the second part 143 of the motion transfer part 140 to compensate for angulation between the first part 141 and the second part 143 of the motion transfer part 140 during operation. The pivot 142 is realized here as an integral hinge. The coupling unit 200 comprises an upper plate 210, which is here integral with the motion transfer part 140; the complete integral part may be made by plastic injection molding. The at least partially deformable cylindrical wall element 220 includes a slot 221 extending from its lower end to the height of the top plate 210 to allow the wall element 220 to be at least partially deformable due to its elastic properties. The at least partially deformable cylindrical wall element 220 may be made from a thin, bent metal sheet, for example, the metal sheet may have a thickness of 50 micrometers to 500 micrometers, preferably 75 micrometers to 250 micrometers, e.g., 75 micrometers, 100 micrometers, 125 micrometers, 150 micrometers, 175 micrometers, 200 micrometers, 225 micrometers, or 250 micrometers. These thickness values ​​are generally applicable to all embodiments including sheet metal components. The at least partially deformable cylindrical wall element 220 may be connected to the top plate 210 by at least one, preferably at least two, crimping projections 211 extending from the top plate 210. This does not exclude that the wall element 220 may be fixed to the top plate 210 by other or additional techniques, such as (laser) welding, gluing, riveting, screwing, etc. Instead of or in addition to the slot 221, the wall element 220 may comprise a slot 222, which is shown in dashed lines and which may extend along the entire length of the wall element 220.The coupling unit 200 comprises a receiver opening 250 that allows the essentially cylindrical drive shaft coupling end to enter an imaginary receiver cylinder 251 (see FIG. 4A).

[0020] FIG. 4C shows the same cross-sectional view as shown in FIG. 4A , but only a portion of the attachment 100, including the upper portion of a drive shaft 31 having an essentially cylindrical drive shaft coupling end 30, shown here in a coupled state received within an imaginary receiver cylinder 251. As already described in connection with FIG. 3 , the essentially cylindrical drive shaft coupling end 30 can comprise a magnet or magnetizable element 32, a cap 34, and adhesive 33 that securely connects the cap 34, the magnet or magnetizable element 32, and the drive shaft 31 together. However, it should be noted that magnetic interaction capability is not important here, since the attachments described herein are mechanically attached to the essentially cylindrical drive shaft coupling end 30. Thus, the essentially cylindrical drive shaft coupling end 30 can simply be a cylinder, e.g., a plastic or metal cylinder. A reduced diameter portion 36 can extend below the essentially cylindrical drive shaft coupling end 30, thereby providing an undercut therein according to the definition of “undercut” provided in the previous paragraph. The embodiment shown in Figures 7A to 11B takes advantage of the presence of such an undercut beneath the essentially cylindrical drive shaft coupling end 30. It should be noted that instead of a reduced diameter portion achieving the undercut, a groove or individual receptacle may be provided in the essentially cylindrical drive shaft coupling end 30 to achieve the undercut.

[0021] Figure 4D is a perspective view of an attachment 100' that is essentially identical to the attachment 100 shown in Figures 4A and 4C, but with the outer attachment tube 110 shown transparent and the first mechanical connector 300 located at the lower end of the attachment 100', the term lower end referring to the end of the attachment 100' that is intended to be coupled with a handle. The other elements shown in Figure 4D have already been described, so please refer to the above description of Figures 4A-4C.

[0022] 5A and 5B are diagrams of a second example of an attachment 100A proposed herein. Elements of this embodiment that remain essentially the same as those in FIGS. 4A and 4B will not be described again (reference numerals will change, for example, from 120 to 120A or 120B in the following embodiments), and only the differences will be highlighted. This also applies to the following description of FIGS. 13A and 13B. Instead of an integral hinge as described for the first exemplary embodiment, the second exemplary embodiment includes a pivot 142A realized by a swivel joint having a pivot axis 1421A. The pivot 142A allows the first and second portions 141A and 143A of the motion transmission part 140A to pivot relative to each other, enabling changes in the angulation between the first and second portions 141A and 143A. The coupling unit 200A comprises an upper plate 210A and an at least partially deformable, essentially cylindrical wall element 220A defining an imaginary receiver cylinder 251A for receiving the essentially cylindrical drive shaft coupling end of the drive shaft. The upper plate 210A and the second part 143A of the motion transfer part 140A may be made of a metal such as non-magnetic steel, and the partially deformable, essentially cylindrical wall element 220A may also be made of a non-magnetic thin metal sheet material and may be connected to the upper plate 210A by laser welding or any other metal connection technique such as adhesive bonding, screwing, riveting, etc.

[0023] 6A and 6B are diagrams of a third example of the attachment 100B proposed herein. Here, a spring 250B is disposed between a coupling unit 200B and an outer attachment tube 110B, biasing the coupling unit 200B toward an opening 111B at the lower end of the attachment 110B. Here, the spring 250B abuts at one end against an annular abutment surface 112B on the inner surface of the outer attachment tube 110B, and at the other end against an upper abutment surface 212B of the upper plate 210B of the coupling unit 200B. The spring 250B supports the attachment of the coupling unit 200B onto the essentially cylindrical drive shaft coupling end of the drive shaft during the attachment process. The outer attachment tube 110B may have an essentially cylindrical inner portion 113B that provides a guide for the spring 250B, preventing the spring from expanding or moving laterally. The coupling unit 200B here comprises an upper plate 210B and an at least partially deformable essentially cylindrical wall element 220B, which may be made from plastic and may be realized as an integral part together with the motion transmission part 140B. As discussed with respect to the previous embodiment, the at least partially deformable essentially cylindrical wall element 220B may be provided with slots or other cutouts 221B that support deformation of the at least partially deformable essentially cylindrical wall element 220B.

[0024] 7A and 7B are diagrams of a fourth example of the attachment 100C proposed herein. The attachment 100C includes a coupling unit 200C that has some similarities to a secondary closure for a champagne bottle. The coupling unit 200C has two flexible or pivotable wall elements 2210C and 2220C attached to an upper plate 210C of the coupling unit 200C. Each of the two flexible wall elements 2210C and 2220C is flexible or pivotable about an axis 225C, i.e., an axis defined by the axis 225C, against a restoring spring force. In their rest position, the two flexible wall elements 2210C and 2220C enclose an imaginary receiver cylinder 251C for receiving the essentially cylindrical drive shaft coupling end of the drive shaft. Each of the two deflectable wall elements 2210C and 2220C comprises a spring extension 2211C and 2221C, respectively, abutting against an abutment surface 1431C of the second part 143C of the motion transmitting part 140C, but this is considered non-limiting and the restoring spring force may be provided in other ways. When one of the two deflectable wall elements 2210C or 2220C is deflected essentially radially outward about the axis 225C, the respective spring extension 2211C or 2221C is pressed against the second part 143C of the motion transmitting part 140C and thus elastically deforms, thereby generating a restoring spring force that pushes the deflected wall element 2210C or 2220C back to its rest position. In the illustrated embodiment, each of the two deflectable wall elements 2210C and 2220C includes a notch 2212C and 2222C, respectively, provided at its lower end and a radially inwardly extending protrusion 2213C and 2223C, respectively. The protrusions 2213C and 2223C may be realized as being integral with the respective deflectable wall element 2210C and 2220C on which they are provided. For example, the wall elements 2210C and 2220C may be made from a thin metal sheet material, and the protrusions 2213C and 2223C may be made from a rolled, folded, or bent piece of metal sheet material, as shown in FIG. 7B .When the essentially cylindrical drive shaft coupling end enters the imaginary receiver cylinder 251C, the protrusions 2213C and 2223C push the two flexible wall elements 2210C and 2220C radially outward, causing them to pivot about axis 225C until the protrusions 2213C and 2223C snap into an undercut, such as a reduced diameter portion below the essentially cylindrical drive shaft coupling end, or a groove or receptacle provided in the essentially cylindrical drive shaft coupling end.

[0025] 8A and 8B are diagrams of a fifth example of an attachment 100D proposed herein. The attachment 100D comprises a coupling unit 200D with two flexible wall elements 2210D and 2220D that define a virtual receiver cylinder 251D. In contrast to the fourth embodiment, the two flexible wall elements are not arranged to be pivotable about an axis, but are arranged to be flexible or bendable due to the elasticity of the material from which they are made; for example, they may be made of metal sheet material. The upper plate 210D and the motion transmission part 140D of the coupling unit 200D are an integral part that can be made by plastic injection molding. The two flexible wall elements 2210D and 2220D may be connected to the upper plate 210D by one or several crimping projections 211D or other techniques, as already described with reference to FIG. 4B. Furthermore, the two deflectable wall elements 2210D and 2220D each comprise a protrusion 2213D and 2223D, respectively, extending radially inward. The protrusions 2213D and 2223D may be made by stamping or bending. It should be noted here that, for clarity, in this embodiment the protrusions 2213D and 2223D are realized in a different way than the protrusions described with respect to the fourth exemplary embodiment, but this should not be understood as limiting. All methods for realizing protrusions may be used interchangeably in all embodiments in which protrusions are used; in particular, two or more protrusions do not all have to be made in the same way.

[0026] 9A and 9B are diagrams of a sixth example of the attachment 100E proposed herein. This embodiment has some similarities to the embodiment shown in FIGS. 8A and 8B, but here the top plate 210E and the two deflectable wall elements 2210E and 2220E that define the imaginary receiver cylinder 251E are realized together as a single piece, for example, a plastic injection-molded part. The single piece may also include a motion-transmitting portion 140E. The two deflectable wall elements 2210E and 2220E may again include radially inwardly extending protrusions 2213E and 2223E, respectively, which may be made in this embodiment by a plastic injection-molding process.

[0027] 10A and 10B are diagrams of a seventh example of an attachment 100F proposed herein. The attachment 100F comprises a coupling unit 200 detachably coupled to at least a portion of a motion transmission part 140F. More precisely, in the illustrated embodiment, a first part 141F of the motion transmission part 140F terminates in a first detachable coupling part 1421F that is detachably coupled to a second detachable coupling part 1422F, and the first and second detachable coupling parts 1421F and 1422F together form a detachable joint 142F, which may be realized as a detachable ball joint. The first detachable coupling part 1421F is realized here as a spherical end of the first part 141F of the motion transmission part 140F, and the second detachable coupling part 1422F comprises several flexible arms that define a spherical receiver volume that can receive the spherical end. The coupling unit 200F is here realized integrally with the second separable coupling portion 1422F and the second portion 143F of the motion transmission part 140F, whereby together they form a separable adapter 400F, which may be realized as a plastic injection-molded part. The coupling unit 200F here comprises two flexible wall elements 2210F and 2220F that define a virtual receiver cylinder 251F, each of the two flexible wall elements 2210F and 2220F comprising radially inwardly extending protrusions 2213F and 2223F, respectively, that may be structured to enable only one-time attachment to an essentially cylindrical drive shaft coupling end by engaging undercuts. Once the coupling unit 200F is attached to the essentially cylindrical drive shaft coupling end, it may be removable only by breaking the protrusions 2213F and 2223F. Alternatively, protrusions 2213F and 2223F may be shaped such that coupling unit 200F can be removed from the essentially cylindrical drive shaft coupling end only by applying a relatively high force without destroying protrusions 2213F and 2223F. Such a removal force may be well in excess of the normal forces acting on adapter 400F during normal operation; for example, the removal force may be greater than 15N, greater than 20N, or greater than 25N.The removal force should in particular be set higher than the separation force required to separate the separable joint 142F. The basic idea here is that the integral part comprising the coupling unit 200F, the second part of the motion transmission 143F and the second separable coupling part 1422F remains attached to the essentially cylindrical drive shaft coupling end, while the remaining part of the attachment 100F can be replaced when it wears out or to attach a different attachment serving a different purpose.

[0028] 11A and 11B are diagrams of an eighth example of an attachment 100G proposed herein. The eighth exemplary embodiment combines the seventh embodiment described with reference to FIGS. 10A and 10B with the spring 250G described with reference to FIGS. 6A and 6B for the third embodiment. This eighth embodiment is provided specifically to demonstrate that the various aspects described herein can be combined to the extent that they are not mutually exclusive.

[0029] 12A and 12B are diagrams of a ninth example of an attachment 100H proposed herein. This ninth embodiment is a variation of the seventh embodiment having a separable pivot joint 142F; the ninth embodiment also includes a separable pivot joint 142H. However, instead of two deflectable wall elements, the coupling portion 200H of the ninth embodiment includes a deformable, essentially cylindrical wall element 220H that defines a cylindrical receiver volume 251H. The deformable, essentially cylindrical wall element 220H can be made of an elastomeric material, such as synthetic or natural rubber.

[0030] 13A and 13B are diagrams of a tenth example of the attachment 100I proposed herein. This tenth embodiment deviates from all previously described embodiments insofar as it does not include a wall element for defining a cylindrical wall element. Instead, the coupling unit 200I includes only an upper plate 210I having a flat coupling surface 215I configured to be biased against the flat coupling surface of the essentially cylindrical drive shaft coupling end when the attachment 100I is attached to the handle. A spring 250I serves to apply the biasing force. As previously described, the spring 250I is disposed between the inner annular abutment protrusion of the outer attachment tube 110I and the upper plate 210I. The upper plate 210I may be guided by the inner cylindrical portion 113I of the outer attachment tube 110I. In addition to what is shown here, the top plate 210I may be provided with one or several downwardly extending alignment protrusions to establish positional alignment between the flat coupling surface 215I and the coupling surface of the essentially cylindrical drive shaft coupling end. The spring 250I and its spring constant should be selected so that the flat coupling surface 215I always remains in contact with the coupling surface of the essentially cylindrical drive shaft coupling end. The drive of the handle then needs to act on the spring 250I during the phase in which the drive shaft moves upward, compressing the spring, but this stored energy is released again when the spring support pushes the drive shaft downward. Only the plastic deformation of the spring and the conversion of motion to heat cause additional drive losses. This also applies to other embodiments with biasing springs.

[0031] 14 is a perspective view of the coupling end of an oral care device handle 320, which includes an essentially cylindrical drive shaft coupling end 330 and a drive shaft housing 322. As previously described, the drive shaft housing can function to mechanically receive the outer attachment tube of an oral care device attachment, thereby removably coupling the two to one another. The drive shaft housing 322 has a somewhat elongated cross-sectional shape, such as an oval or elliptical shape, such that the inner hollow portion of the drive shaft housing 322 that accommodates the essentially cylindrical drive shaft coupling end 330 also has an essentially elongated cross-sectional shape. Preferably, the essentially cylindrical drive shaft coupling end 330 is not coaxially or centrally disposed within the hollow portion of the drive shaft housing 322, thereby resulting in a gap 323 having a variable width between the drive shaft housing 322 and the essentially cylindrical drive shaft coupling end 330. As visualized in FIG. 14 , the width of the gap 323 between the essentially cylindrical drive shaft coupling end 330 and the drive shaft housing 322 in a plane perpendicular to the extension axis of the drive shaft (see axis L in FIG. 3 ) may have a minimum value w1 and a maximum value w2. In one example, the minimum width w1 may be approximately 0.6 mm and the maximum width w2 may be approximately 1.0 mm. More generally, without limitation, the minimum width w1 may range from 0.3 mm to 0.9 mm, and the maximum width w2 may range from 0.6 mm to 2.0 mm. The difference between the minimum width w1 and the maximum width w2 may be at least approximately 0.1 mm, preferably at least 0.2 mm, and more preferably at least approximately 0.4 mm. Instead of or in addition to the eccentric arrangement between the essentially cylindrical drive shaft coupling end 330 and the drive shaft housing 322, the drive shaft housing 322 may be provided with one or several pockets 3221, 3222, 3223 on its inner wall. At least one pocket 3221, 3222, 3223 can have a circumferential extension of at least about 10 degrees, preferably at least 20 degrees, more preferably at least about 30 degrees, and even more preferably at least about 45 degrees. In some examples, the circumferential extension may be at least 60 degrees.In some examples, the drive shaft housing 322 can have two, three, four, or five such pockets. In a preferred example, the drive shaft housing 322 has three pockets as shown in FIG. 14, although the dimensions shown in FIG. 14 are merely exemplary. The length extension of at least one pocket 3221, 3222, 3223 along the drive shaft extension axis (see axis L in FIG. 3) may be, but is not limited to, at least about 1 mm, preferably at least about 2 mm, more preferably at least about 3 mm, and preferably less than about 20 mm. The depth of the pocket across the width of the gap 323 may be at least about 0.05 mm, preferably at least about 0.1 mm, more preferably at least about 0.15 mm, and even more preferably at least about 0.2 mm.

[0032] The just-described structure of the gap 322 between the essentially cylindrical drive shaft coupling end 330 and the drive shaft housing 320 may be reflected in the dimensions of the at least partially deformable essentially cylindrical wall element or at least two elastic or flexible wall elements, which have already been described with reference to numerous embodiments. This means, for example, that the width of the at least partially deformable essentially cylindrical wall element can vary circumferentially, using the available space provided by the gap. The at least partially deformable essentially cylindrical wall element may then have a smaller width, with the width w1 of the gap 323 being the smallest, or a larger width, with the width w2 of the gap 323 being the largest. The actual width selected depends on the tolerances of the various elements and may also depend on the lateral movement of the essentially cylindrical drive shaft end 330 during operation. The same applies to the width(s) of one or more of the at least two elastic or flexible wall elements, with at least one of these wall elements having a larger width than the other(s). Matching the width of the wall element(s) to the available gap width may be beneficial for the strength of the coupling. The wall element(s) may also be adapted to the geometric shape provided by the at least one pocket 3221, 3222, 3223, i.e. the wall element(s) may have respective thickened portions that protrude towards or may even extend into the at least one pocket 3221, 3222, 3223.

[0033] 13A and 13B, one or more downwardly extending alignment protrusions for establishing alignment between the flat mating surface 215I and the mating surface of the essentially cylindrical drive shaft mating end may be dimensioned to extend into the space provided by or at least align with at least one pocket 3221, 3222, 3223, so that the increased width of the gap avoids collision between the protrusions and the inner wall of the drive shaft housing 322. In one example, the drive shaft housing 322 includes three pockets 3221, 3222, 3223, preferably evenly distributed circumferentially, and the oral care device attachment includes three downwardly extending alignment protrusions, evenly distributed circumferentially, for establishing alignment between the flat mating surface 215I and the mating surface of the essentially cylindrical drive shaft mating end.

[0034] According to one aspect, an oral care device attachment is proposed for connection to an oral care device handle having an essentially cylindrical drive shaft connection end, the attachment comprising: an outer attachment tube having a connection end intended to be removably fixed to a housing of the oral care device handle; a carrier attached to the outer attachment tube for driving movement; and a motion transmission part arranged inside the outer attachment tube, the motion transmission part having a first end connected to the carrier and a second end arranged to connect to the essentially cylindrical drive shaft connection end, the second end comprising a connection unit having an upper plate and one elastic or flexible wall element extending from the upper plate, the elastic or flexible wall element having a protrusion protruding inward.

[0035] The embodiment described in the previous paragraph may be arranged such that one resilient or flexible wall element is aligned with the maximum width of the gap between the essentially cylindrical drive shaft coupling end and the drive shaft housing. In such an example, the coupling unit may be at least a portion of a separable adapter, and preferably, at least a portion of the motion transmission section and the separable adapter are coupled by a separable coupling, such as a separable ball joint. This allows the separable adapter with one resilient or flexible wall element to be first introduced into the maximum width gap region until the inwardly protruding protrusion snaps into the undercut of the essentially cylindrical drive shaft coupling end, then rotated to a position where the one resilient or flexible wall element extends through the smaller width gap region, and then rotated to a position where the separable adapter cannot be easily separated from the essentially cylindrical drive shaft coupling end because no gap width is available for removal, before rotating the separable adapter back to a position where the one resilient or flexible wall element again extends through the wider width gap portion. Other elements as described in this disclosure, such as a biasing spring, may also be added to this embodiment.

[0036] Dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

Claims

1. 1. An oral care device attachment for coupling to an oral care device handle having an essentially cylindrical drive shaft coupling end, said attachment comprising: an outer attachment tube having a coupling end intended to be removably secured to a housing of the oral care device handle; a carrier attached to said outer attachment tube for driving movement; a motion transmission part disposed inside the outer attachment tube, the motion transmission part having a first end coupled to the carrier and a second end arranged for coupling to the essentially cylindrical drive shaft coupling end, the second end comprising a coupling unit each having a top plate and at least one at least partially deformable essentially cylindrical wall element extending from the top plate, or at least two elastic or flexible wall elements extending from the top plate, each of the elastic or flexible wall elements extending over a portion of an imaginary receiver cylinder such that an essentially cylindrical receiver receptacle is defined by the top plate and the one at least partially deformable essentially cylindrical wall element, or by the top plate and the at least two elastic or flexible wall elements; An oral care device attachment comprising:

2. Attachment according to claim 1 , wherein the at least partially deformable essentially cylindrical wall element is at least partially made from a thermoplastic elastomer or natural rubber.

3. Attachment according to claim 1 , wherein the at least partially deformable essentially cylindrical wall element or the at least two elastic or flexible wall elements are at least partially made from a thermoplastic material.

4. 4. An attachment according to claim 3, wherein the upper plate is made from a thermoplastic material, and preferably the upper plate and the at least partially deformable essentially cylindrical wall element or the at least two elastic or flexible wall elements are realised as a single-piece integral unit.

5. 2. An attachment according to claim 1, wherein the at least partially deformable essentially cylindrical wall element or the at least two elastic or flexible wall elements are at least partially made from sheet metal, in particular non-magnetic sheet metal, preferably the sheet metal having a thickness of less than or equal to about 250 micrometers, more preferably less than or equal to about 150 micrometers.

6. 6. The attachment according to claim 5, wherein the upper plate is made from a thermoplastic material and the at least partially deformable essentially cylindrical wall element or the at least two elastic or flexible wall elements are connected to the upper plate by at least one connection technique from the group of welding, snapping, riveting, adhesive and / or screwing.

7. Attachment according to claim 5, wherein the upper plate is made from metal, in particular a non-magnetic metal, and the at least partially deformable, essentially cylindrical wall element or the at least two elastic or flexible wall elements are connected to the upper plate by at least one connection technique from the group of welding, snapping, caulking, gluing, screwing and / or overmolding.

8. 8. An attachment according to any one of claims 1 to 7, wherein the at least partially deformable essentially cylindrical wall element or at least one of the at least two elastic or flexible wall elements is provided with an inwardly projecting protrusion.

9. 9. An attachment according to any one of claims 1 to 8, wherein a spring is disposed between the outer attachment tube and the motion transmission part, biasing the motion transmission part towards the coupling end of the outer attachment tube.

10. 10. An attachment according to any one of claims 1 to 9, wherein at least one of the at least two resilient or flexible wall elements is biased to a rest or clamped position relative to the motion transmission part by a spring providing a biasing force, the biased resilient or flexible wall element being pivotable about a pivot axis when a force acts on the biased resilient or flexible wall element against the biasing force, preferably the biasing spring being realised as a single-piece element together with the biased resilient or flexible wall element.

11. 11. An attachment according to any one of claims 1 to 10, wherein the coupling unit is or is part of a separable adapter, and preferably at least part of the motion transmission part and the separable adapter are coupled by a separable coupling such as a separable ball joint.

12. 12. An oral care device comprising: an attachment according to any one of claims 1 to 11; and an oral care device handle having an essentially cylindrical drive shaft coupling end coupled to the attachment, wherein the attachment is coupled to the essentially cylindrical drive shaft coupling end such that at least a portion of the essentially cylindrical drive shaft coupling end is received in the essentially cylindrical receiver receptacle.

13. 13. The oral care device of claim 12, wherein the attachment is coupled to the essentially cylindrical drive shaft coupling end such that the essentially cylindrical drive shaft coupling end is fully received within the essentially cylindrical receiver receptacle, and preferably an inwardly protruding protrusion realized in the at least partially deformable essentially cylindrical wall element extending from the upper plate or in at least one of the at least two elastic or flexible wall elements extending from the upper plate extends below the essentially cylindrical drive shaft coupling end.

14. An oral care device as described in claim 12 or 13, wherein there is a circumferential gap of less than about 1 mm, preferably less than about 0.8 mm, and more preferably less than about 0.6 mm between the essentially cylindrical drive shaft coupling end and a portion of the oral care device handle housing.

15. A kit comprising: at least one attachment comprising: an outer attachment tube having a coupling end intended to be coupled with the oral care device handle; a carrier attached to the outer attachment tube for a driving movement; and a motion transmission part disposed inside the outer attachment tube, the motion transmission part having a first end coupled with the carrier and a second end comprising a first side of a separable joint; an adapter coupled to a drive shaft of an oral care device handle having an essentially cylindrical drive shaft coupling end and coupled to the attachment, the adapter comprising: a first end comprising a second side of the separable joint; and a second end comprising coupling units each having a top plate and at least one at least partially deformable essentially cylindrical wall element extending from the top plate, or at least two elastic or flexible wall elements extending from the top plate, each of the flexible wall elements extending across a portion of an imaginary receiver cylinder such that an essentially cylindrical receiver receptacle is defined by the top plate and the one at least partially deformable essentially cylindrical wall element, or by the top plate and the at least two elastic or flexible wall elements; A kit comprising:

16. 1. An oral care device attachment for coupling to a drive shaft of an oral care device handle having an essentially cylindrical drive shaft coupling end, said attachment comprising: an outer attachment tube having a coupling end intended to be secured to the oral care device handle; a carrier attached to said outer attachment tube for driving movement; a motion transmission part disposed inside the outer attachment tube, the motion transmission part having a first end coupled to the carrier and a second end configured to be coupled to the essentially cylindrical drive shaft coupling end, the second end comprising a coupling unit having an upper plate; An oral care device attachment, wherein a spring is disposed between the outer attachment tube and the motion transmission part, biasing the motion transmission part toward the coupling end of the outer attachment tube.

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