toothbrush

Abstract

A toothbrush having a handle, at least one cleaning zone, and at least one deformable element, the deformable element having a first flexible arm disposed relatively toward the cleaning zone and a second flexible arm disposed relatively away from the cleaning zone. The deformable element is movable from a rest position in which the first arm is substantially flat and aligned with the handle to a cleaning position in which the first arm and the cleaning zone adopt the curvature of the surface of the dentition, the arms forming a wedge shape connected to each other at one end of the deformable element and separated from each other at the other end of the deformable element. The first and second arms are linked by at least two bridges tiltable relative to the first and second arms when pressure is applied to the cleaning zone, the arms and bridges enclose a void space.

Description

[Technical field]

[0001] The present invention relates to a toothbrush, in particular to a toothbrush having a cleaning zone that can be adapted to the shape of the tooth surface. [Background technology]

[0002] Toothbrushes are known tools and generally comprise a handle in which the toothbrush is held and a cleaning zone (commonly known as a "head") in which the tooth cleaning elements are arranged and which are pressed with a cleaning pressure against the teeth during cleaning. The head and handle define a handle-head longitudinal direction of the toothbrush, with a longitudinal neck between the head and the handle. The tooth cleaning elements usually project from the cleaning zone in a direction transverse to the longitudinal direction. Summary of the Invention [Problem to be solved by the invention]

[0003] WO 2006 / 089784 discloses a toothbrush comprising a cleaning zone and a deformable element that allows the cleaning zone to adapt to the shape of the tooth surface when a cleaning pressure is applied by the user. The deformable element of the toothbrush comprises at least a first flexible wing arranged relatively towards the cleaning zone and a second flexible wing arranged relatively away from the cleaning zone, and comprises at least one guiding element integrally formed with the wing, the first and second wings retaining a wedge-shaped space at least partially filled with an elastic material, gel or fluid. This solution does not have a satisfactory deformability due to the material used and the filling of the wedge-shaped space.

[0004] Currently, there remains a need for improved toothbrushes that conform to the shape of the tooth surfaces and therefore effectively clean the teeth while reducing the risk of breakage and difficulty in manufacturing. [Means for solving the problem]

[0005] The present disclosure provides a toothbrush having a handle, at least one cleaning zone, and at least one deformable element, the deformable element having a first flexible arm arranged relatively towards the cleaning zone and a second flexible arm arranged relatively away from the cleaning zone. According to the present invention, the deformable element can move from a rest position in which the first arm is substantially flat and aligned with the handle to a cleaning position in which the first arm and the cleaning zone adopt the curvature of the surface of the dentition. According to the present invention, the arms form a wedge shape connected to each other at one end and away from each other at the other end, the first and second arms are linked by at least two bridges that are tiltable relative to the first and second arms when pressure is applied to the cleaning zone, the arms and bridges enclose a void space. Because the bridges are tiltable relative to the arms, the deformable element can adopt the curvature of the surface of the dentition when pressure is applied to the cleaning zone. The arrangement of the arms and bridges within the deformable element recalls the structure of a fish fin, with two bones arranged in a wedge shape connected by connective tissue. Inspired by the analysis of fish fins, biologist Leif Kniese discovered the FIN RAY effect, where applying a force to a fin-like structure causes the base and tip to deform toward the applied force. This technology has been used in namely robotic grippers, but not in the area of ​​oral hygiene in general or toothbrushes in general. The inclusion of void space between the arms and bridges allows the deformable element of the present invention to easily bend toward the applied load in the cleaning position. Providing void space within the deformable element also reduces the manufacturing complexity of the toothbrush, as this feature removes the need for additional manufacturing steps such as filling the voids with an elastic material, gel, or fluid.

[0006] In one embodiment, the arms and bridge are integrally formed by injection moulding, which makes manufacture particularly efficient and reduces the risk of separation of the arms and bridge during use.

[0007] In one embodiment, the arms and bridge are made from a thermoplastic elastomer (TPE) material. TPE is a class of polymeric materials that have both thermoplastic and elastomeric properties that provide the desired flexibility and solidity.

[0008] According to a preferred embodiment, the TPE material has a Shore D hardness of about 50-66, preferably about 54-62, more preferably about 56-60, most preferably about 58. The use of such a TPE material provides sufficient flexibility to the deformable element to move to the cleaning position when a force is applied to the cleaning zone, while also providing ease of manufacture on a large scale. Furthermore, a reliable adhesion to the gel pad can be obtained.

[0009] In one embodiment, the bridge comprises a hinge flexibly connecting the bridge to the arm. Such hinge allows the required tilting. Preferably, the angle between the bridge and the arm is about 90° in the rest position, and when pressure is applied to the cleaning zone and the bridge tilts relative to the arm, the angle increases to about 95°-110°, preferably about 97°-105°.

[0010] According to a preferred embodiment, said hinge is a one-piece hinge, i.e. the hinge is formed integrally with the connecting arms and bridge during the manufacturing process, preferably made from the same material during an injection moulding process, which is particularly advantageous in terms of tilt angle and ease of manufacture, reducing the risk of breakage.

[0011] According to a preferred embodiment, the integral hinge has a thickness in the longitudinal direction of the toothbrush of about 0.2-0.4 mm. This is advantageous as it provides the integral hinge with the required flexibility while minimizing the risk of breakage. This is particularly advantageous when using a TPE material with a Shore D hardness of 54-62.

[0012] In one embodiment, the distance between the arms at the proximal end of the deformable element is about 3 mm to 5 mm, preferably 3.5 mm to 4.5 mm, which is advantageous as it reduces the risk of breakage, increases the efficiency of cleaning, and is compact enough to fit comfortably in the user's mouth during cleaning.

[0013] In one embodiment, the longitudinal distance between the bridges is about 5-9 mm, preferably 7-8 mm. Furthermore, the longitudinal distance between the bridge closest to the tip of the toothbrush head and the tip is also preferably 5-9 mm, preferably 7-8 mm. Preferably, the longitudinal distance between the bridge closest to the handle and the end of the deformable element, i.e. the length of the gap closest to the toothbrush handle, is preferably smaller than the longitudinal distance between the bridges, for example 5-6 mm. Various tests have shown that these dimensions, i.e. in combination with the use of three bridges, provide optimal results in terms of deformability and cleaning performance.

[0014] In one embodiment, the deformable element is no more than 150% of the length of the cleaning zone, preferably no more than 130% of the length of the cleaning zone. Consumer tests have shown that an excessively long deformable element causes an unpleasant sensation in the mouth of the user. A deformable element that is no more than 130% of the length of the cleaning zone also reduces the difficulty of the molding manufacturing process and the possibility of breakage during use.

[0015] In one embodiment, the deformable element has 2-7 bridges, preferably 3-5 bridges, most preferably 3 bridges. It has been found that less than 3 bridges do not provide the desired deformation characteristics, i.e. the deformable element is still too rigid with only 2 bridges. On the other hand, consumer tests have shown that consumers do not like to have too many bridges in the deformable element of a toothbrush. An excessive number of bridges often requires a longer deformable element as well, which creates an unpleasant sensation during brushing. The larger void space associated with the additional bridges may also be more prone to being filled with toothpaste and thus require additional post-brushing cleaning. Toothbrushes with 3 bridges are preferred because such toothbrushes have optimal functionality, i.e. in terms of cleaning characteristics, while minimizing user discomfort and void space size.

[0016] In one embodiment, the handle comprises a polypropylene skeleton and is integrally formed in one piece with the deformable element by injection molding.

[0017] In one embodiment, the deformable element is made of a material, preferably a TPE, with an elongation at break of 500-800%, preferably 600-750%, more preferably 650-700%, which provides the required flexibility and reduces the risk of breakage during use.

[0018] In another preferred embodiment, the deformable element is made of a material, preferably a TPE, with a tensile strength of 25-36 MPa, preferably 30-33 MPa, more preferably 31-32 MPa. The tensile strength influences the adhesive and physical properties, and values ​​within these ranges provided the best results with regard to adhesion of the deformable element to the gel pad and with regard to the risk of breakage. Effect of the Invention

[0019] The toothbrush of the present invention is formed by a cascade injection molding process. In a single cavity in a mold, TPE is injected to form the deformable element and neck area, while polypropylene (PP) is injected to produce the skeleton for the handle area. Different TPE materials are injected on top of or around the PP skeleton to provide the desired surface feel and grip. The TPE and PP materials of the deformable element and handle are mixed together in the contact zone, and all materials used are bonded to each other in this bi-injection molding process. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 shows a side view of the neck and head of the toothbrush when not in use. [Diagram 2] 1 shows a side view of the neck and cleaning zone of a toothbrush during brushing of the dentition, the inset shows a detailed view of the bridge and hinge of the toothbrush. [Diagram 3] A side cutaway view of the toothbrush is shown, the cut being along the length of the cleaning zone-handle. [Figure 4] 4 shows a cut through the head of the toothbrush in the rest position, along a plane perpendicular to the view of FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Figure 1 shows a side view of the head and neck of a toothbrush according to an embodiment of the invention. The toothbrush comprises a head 5, which is made up of a cleaning zone 2 and a deformable element 3, and a toothbrush neck 12, which connects the head 5 to a handle 1 (see Figure 4, not shown in Figure 1). The cleaning zone 2 has a gel pad 22 which holds cleaning elements 21. The cleaning elements 21 of the depicted toothbrush are bristles arranged in tufts (tufts not shown in the figures), as is typical for toothbrushes. The gel pad 22 is of the order of 12 mm wide and 27 mm long in the longitudinal direction of the cleaning zone 2-handle 1, and is made of a TPE material, i.e. a flexible gel-type material, with a Shore A hardness of 28.

[0022] The deformable element 3 has a first flexible arm 31 on which the cleaning zone 2 is placed, and a gel pad 22 is arranged on the surface of the flexible arm 31. The deformable element 3 further has a second flexible arm 32 arranged relatively away from the cleaning zone 2. The first and second arms 31, 32 form a wedge shape (V-shape), whereby the arms are connected to each other at a distal end 33 and are spaced apart from each other at a proximal end 34 of the deformable element 3 relative to the neck zone 12 and the handle 1. The distance I'''' between the first and second arms 31, 32 at the proximal end 34 of the deformable element 3 is on the order of about 3.5 mm. As the first and second arms 31, 32 converge towards the distal end 33 of the deformable element 3, the distance between the arms decreases as indicated by I, I' and I'', respectively, in FIG. 1. The first and second arms 31, 32 are connected to each other by three bridges 35, 35', 35'' extending in a direction perpendicular to the longitudinal direction of the handle 1. Each bridge 35, 35', 35'' is connected to the first and second flexible arms 31, 32 via an integral hinge 38, which allows the bridge to tilt relative to the first and second arms 31, 32, as shown in the cleaning position depicted in FIG. 2. When pressure is applied to the cleaning zone during brushing, the bridges 35, 35', 35'' tilt, which causes a curvature of the deformable element 3 and brings the two flexible arms 31, 32 closer to each other at their proximal ends 34. Thereby, the cleaning zone 2 of the toothbrush head 5 adopts the curvature of the dentition 40, which leads to a more uniform pressure across the teeth and a reduced risk of gingival irritation. The bridges 35, 35', 35'' have lengths parallel to the distances I, I', I'', and I''' between the arms 31, 32 in a direction transverse to the longitudinal axis of the handle 1 shaft, which increase from the distal bridge 35 to the proximal bridge 35'', and these lengths range from about 2 mm to 3.5 mm. The arms 31, 32 and bridges 35, 35', 35'' surround a plurality of void spaces 36, 36', 36'', 36'''' (see Figures 1 and 2).The lengths of these void spaces 36, 36', 36'', 36''' in the longitudinal direction of the handle 1 are between 5 and 8 mm and are shown as D1, D2, D3 and D4 in FIG. 1. The three distal voids 36, 36', 36'', closer to the tip 33 of the head 5, are similar or equal in length to D1, D2, D3 and all extend below the cleaning zone 2, while the proximal void 36'' has a shorter length D4 and extends beyond the cleaning zone 2 towards the neck 12. The region between the proximal end 34 of the deformable element 3 and the S-bend zone 14 is referred to herein as the neck 12. The S-bend zone 14 serves as a consumer desirable design element and does not provide additional functionality to the toothbrush of the present invention, particularly increased flexibility.

[0023] FIG. 2 shows a side view of the neck 12 and head 5 of the toothbrush during brushing of the surface of the dentition 40, i.e. when pressure is applied for cleaning. The cleaning elements 21 attached to the gel pad 22 contact the surface of the dentition 40 during brushing and exert a force on the cleaning zone 2, which causes the deformable elements 3 to adopt the curvature of the surface of the dentition 40, as already described above. The inset shows a detailed view of one of the bridges 35″ of the deformable elements 3. The bridge 35″ has a thickness of about 0.9 mm in the longitudinal direction in the direction of the handle, as indicated by w2 in the figure. The detailed view shows that the bridge 35″ is connected to the two flexible arms 31, 32 via two hinges 38. These hinges 38 are integrally formed with the bridge 35″ shown in the inset (similar for all three bridges 35, 35′, 35″) and have a thickness of about 0.3 mm, as indicated by w1 in the figure. The integral hinges 38 flexibly connect the bridge 35, 35', 35'' to the first and second arms 31, 32 so that the deformable element 3 can adopt the curvature of the surface of the dentition 40 when a force is applied by the user, as already explained above. When the deformable element 3 deforms under an applied force, the hinges 38 of the bridge 35, 35', 35'' are inclined at an angle α relative to the first and second arms 31, 32, the angle α varying from 90° when no pressure is applied to 120° during cleaning, preferably 110° when pressure is applied.

[0024] FIG. 3 shows a side cutaway view of the toothbrush, the cut being along the length of the handle 1 and perpendicular to the plane of the gel pad 22. The toothbrush is formed by a cascade injection molding process, whereby a TPE material is injected into a single cavity in a mold to form the deformable element 3 and part of the neck 12. The TPE material used for the deformable element has a Shore D hardness of about 50-66, preferably about 54-62, more preferably about 56-60. In this preferred embodiment shown in the figures, the Shore D hardness is about 58. To produce the skeleton of the handle 1 below the S-bend zone 14, polypropylene PP is injected and both materials are mixed in the S-bend zone 14. The TPE and PP adhere to each other in this bi-injection molding process.

[0025] FIG. 4 shows a cut of the head 5 through a plane perpendicular to and passing through the bridges 35, 35', 35'', the toothbrush being in a rest position, i.e. the gel pad 22 is flat. The deformable element 3 has a width, indicated as w5, towards the proximal end 34 relative to the neck 12 and the handle 1, of about 7.2 mm, w5 narrowing slightly as it extends towards the distal end 33, as shown in FIGS. 1 and 2. The three bridges 35, 35', 35'' of the deformable element 3 have a rectangular cross section with rounded edges. As shown in FIG. 2, the width of the bridges 35, 35', 35'' in the longitudinal direction of the handle 1 is about 0.3 mm, indicated here as w2. The width of the bridges 35 in the transverse direction is between about 4.4 and 5 mm, indicated here as w4, w4', and w4''. The gel pad 22 is shown behind the deformable element 3 in a rear view. The gel pad (22) has a capsule shape with rounded ends and has a width that extends beyond the width of the deformable element 3 in a direction perpendicular to the handle 1. The deformable element 3 is manufactured in one piece by injection molding and is made from a thermoplastic elastomer (TPE) material.

[0026] The TPE material used for the deformable element has, as mentioned above, a Shore D hardness of 58. Furthermore, the TPE material has a tensile strength of 25-36 MPa, preferably 30-33 MPa, more preferably 31-32 MPa. In the preferred embodiment shown in the figures, the TPE material has a tensile strength of about 31 MPa. The TPO material used for the deformable element further has a breaking elongation of preferably 500-800%, preferably 600-750%, more preferably 650-700%. In this preferred embodiment, the TPO material has a breaking elongation of 686%. The breaking elongation was measured using the ISO 37 standard test, but, deviating from the standard test protocol, the standard specimen S2 was tested at a travel speed of 200 mm / min. The PP material used for the skeleton of the handle 1 is a conventional PP material, as it is frequently used for toothbrush handles.

Claims

1. A toothbrush having a handle (1), at least one cleaning zone (2), and at least one deformable element (3), the deformable element (3) having a first flexible arm (31) arranged relatively towards the cleaning zone (2) and a second flexible arm (32) arranged relatively away from the cleaning zone (2), the deformable element (3) being movable from a rest position in which the first flexible arm (31) is substantially flat and aligned with the handle (1), to a cleaning position in which the first flexible arm (31) and the cleaning zone (2) adapt to the curvature of the surface of the dentition (40). the first and second flexible arms (31, 32) are connected to each other at one end (33) of the deformable element and form a wedge shape that is spaced apart from each other at the other end (34) of the deformable element, the first and second flexible arms (31, 32) are connected by at least two bridges (35, 35', 35'') that are tiltable relative to the first and second flexible arms (31, 32) when pressure is applied to the cleaning zone (2), and the first and second flexible arms (31, 32) and bridges (35, 35', 35'') surround void spaces (36, 36', 36'', 36''').

2. 2. The toothbrush of claim 1, wherein said first and second flexible arms (31, 32) and said bridge (35) are integrally formed by injection molding.

3. 3. The toothbrush according to claim 1 or 2, wherein the first and second flexible arms (31, 32) and the bridge (35, 35', 35'') are made from a thermoplastic elastomer material (TPE material).

4. 4. The toothbrush of claim 3, wherein the TPE material has a Shore D hardness of about 50-66, preferably about 54-62, more preferably about 56-60, and most preferably about 58.

5. 2. The toothbrush of claim 1, wherein the bridge (35, 35', 35'') has a hinge (38) flexibly connecting the bridge (35, 35', 35'') to the first and second flexible arms (31, 32).

6. 6. The toothbrush of claim 5, wherein said hinge (38) is a living hinge.

7. The toothbrush of claim 6, wherein the living hinge (38) has a thickness in the longitudinal direction of the toothbrush of about 0.2 to 0.4 mm.

8. The toothbrush according to claim 1, wherein the distance (I''') between the first and second flexible arms (31, 32) at the proximal end (34) of the deformable element is between about 3 mm and 5 mm, preferably between 3.5 and 4.5 mm.

9. The longitudinal distance between adjacent bridges (D ２ , D ３ 2. The toothbrush of claim 1, wherein the length of the tooth ridge is about 5 to 9 mm, preferably 7 to 8 mm.

10. 2. The toothbrush according to claim 1, wherein the deformable element (3) is no more than 150% of the length of the cleaning zone (2), preferably no more than 130% of the length of the cleaning zone (2).

11. 2. The toothbrush according to claim 1, wherein the deformable element (3) has 2 to 7 bridges (35, 35', 35''), preferably 3 to 5 bridges (35, 35', 35''), most preferably 3 bridges (35, 35', 35'').

12. 2. The toothbrush according to claim 1, wherein said handle (1) comprises a polypropylene skeleton and is formed in one piece integrally with said deformable element (3) by injection molding.

13. The toothbrush according to claim 1, wherein said deformable element (3) is made of a material having an elongation at break of 500-800%, preferably 600-750%, more preferably 650-700%.

14. 2. The toothbrush according to claim 1, wherein the angle (α) between the bridge (35, 35', 35'') and the first and second flexible arms (31, 32) is about 90° in the rest position and is about 95° to 110°, preferably about 97° to 105° when pressure is applied to the cleaning zone (2).

Images