Brush head of an electric toothbrush

A brush head includes a connecting member detachably mounted in a brush head body, and an elastic element mounted on an outer surface of the connecting member and including a connecting portion with a slot and two clamping portions. A through opening is formed in the connecting member and the middle of each clamping portion is bent inwardly to form an abutting arch capable of deforming elastically in a radial direction of the slot. When the abutting arches are not stressed, the distance between vertex ends of the abutting arches is smaller than a radial thickness of the driving shaft of the electric toothbrush. After the driving shaft is inserted into the slot, the two abutting arches penetrating through the through openings is deformed and directly abut against the driving shaft so that the brush head and the driving shaft are connected stably. The brush head is simple in structure.

TECHNICAL FIELD

The present disclosure relates to the technical field of toothbrushes, in particular to a brush head of an electric toothbrush.

BACKGROUND

With the improvement of living standard, people are paying more and more attention to oral health, and electric toothbrushes are becoming ever popular because of their advantages of being high in cleaning capacity, easy to use and capable of reducing damage to teeth/gums.

A typical electric toothbrush comprise a handle and a replaceable brush head, wherein the handle has a driving shaft protruding out of one end of the handle and is internally provided with a driving device for driving the driving shaft to rotate/vibrate, the driving shaft is inserted into the brush head, and the torque of the driving shaft is transmitted to the brush head by a connecting structure between the driving shaft and the brush head.

It can thus be seen that the connecting structure between the brush head and the driving shaft is of great importance for the connection stability between the brush head and the driving shaft. At present, the connecting structures between the brush head and the handle of the electric toothbrush are of different forms, and some of these structures are complicated and have too many assembled parts, thus resulting in high production costs.

BRIEF SUMMARY OF THE INVENTION

It is desired to provide an improved brush head for an electric toothbrush which is simple in structure and capable of maintaining a stable connection between the brush head and a driving shaft of the electric toothbrush.

A brush head of an electric toothbrush comprises a hollow brush head body; bristles disposed at an end of the brush head body; and a connecting member and an elastic element being disposed in the brush head body. The connecting member is detachably mounted in the brush head body, the connecting member defining a slot to allow a driving shaft of an electric toothbrush to be mounted therein. The elastic element is mounted on an outer surface of the connecting member and comprises a connecting portion and two clamping portions extending from opposite sides of the connecting portion, the connecting portion is located at a top of the connecting member, and ends, close to the connecting portion, of the clamping portions and ends, away from the connecting portion, of the clamping portions are clamped between the connecting member and the brush head body, so that a resilience force is generated in a middle of each said clamping portion. A through opening is formed in a position, corresponding to a middle portion of each of the clamping portions, of the connecting member, and the middle portion of each of the clamping portions is inwardly bent into the through opening to form an abutting arch capable of deforming elastically in a radial direction of the slot. When the abutting arches are not stressed, a distance between vertex ends of the abutting arches is smaller than a radial thickness of the driving shaft of the electric toothbrush, and when the driving shaft is inserted into the slot of the connecting member, the abutting arches extend through the through openings with the vertex ends directly abutting against two opposite sides of the driving shaft respectively.

Compared with the prior art, the embodiments of the invention has the following beneficial effects: the distance between the vertex ends of the two abutting arches is smaller than the radial thickness of the driving shaft when the abutting arches are not stressed. After a handle and the brush head of the electric toothbrush are assembled, the driving shaft will apply an outward expansion force to the clamping portions to cause the abutting arches to deform and the inner wall of the brush head body forces the abutting arches to rebound, so that the two clamping portions tightly clamp the driving shaft from both sides of the driving shaft. The brush head has a simple structure, and the driving shaft is clamped by the elastic element so that a stable connection is formed between the brush head and the driving shaft.

DETAILED DESCRIPTION OF THE INVENTION

To allow those skilled in the art to have a better understanding of the technical solution of the embodiments of the invention, the technical solution of the embodiments of the invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments. Obviously, the embodiments in the following description are merely illustrative ones, and not all possible ones of the invention. All other embodiments obtained by those ordinarily skilled in the art based on the following ones should also fall within the protection scope of the embodiments of the invention.

Referring toFIG. 1andFIG. 2which illustrate a preferred embodiment of the invention, an electric toothbrush comprises a handle1and a replaceable brush head2, wherein a driving shaft11protrudes out of one end of the handle1and is being insertable into the brush head2.

The brush head2of the electric toothbrush comprises a hollow brush head body21, bristles22, a connecting member23, an elastic element24and a decorative ring25. The bristles22are located at one end of the brush head body21, the connecting member23is detachably mounted in the brush head body21, the elastic element24is mounted on the outer surface of the connecting member23, and the decorative ring25is located at an end, close to the handle1, of the brush head body21and is different in color from the handle1and the brush head body21to identify the brush head2.

Referring alsoFIG. 3toFIG. 8, a mounting hole211matching the connecting member23in shape is formed in an end, away from the bristles22, of the brush head body21, and the connecting member23is mounted in the mounting hole211. A slot231allowing the driving shaft11to be mounted therein is formed in the connecting member23. The elastic element24is formed by an integrally bent metal sheet and comprises a connecting portion241and two clamping portions242which are bent from two opposite sides of the connecting portion241respectively. The connecting portion241is located at the top of the connecting member23. Ends2421, close to the connecting portion241, of the clamping portions242and ends2422, away from the connecting portion241, of the clamping portions242are clamped between the connecting member23and the brush head body21, so that a resilience force is generated in the middle of each clamping portion242. A through opening232is formed in a position, corresponding to the middle of each clamping portion242, of the connecting member23. The middle of the clamping portions242are bent toward each other to form abutting arches2423capable of deforming elastically in the radial direction of the slot231. When the driving shaft11is inserted into the slot231of the connecting member23, the two abutting arches2423penetrating through the through openings232directly abut against two opposite sides of the driving shaft11. When the abutting arches2423are not stressed, the distance between vertexes of the two abutting arches2423is smaller than the radial thickness of the driving shaft11between the two opposite sides.

When the brush head2and the handle1are assembled together, the driving shaft11is inserted into the slot231and applies an outward expansion force to the two abutting arches2423to cause the abutting arches2423to deform. Because the two ends2421and2422of the clamping portions242are clamped between the connecting member23and the brush head body21, the abutting arches2423are forced to rebound to enable the two clamping portions242to tightly clamp the driving shaft11from both sides. When the electric toothbrush is used, the driving shaft11is clamped by the elastic element24to be firmly assembled with the connecting member23so that the driving shaft11drives the bristles22to rotate/vibrate to complete cleaning.

Specifically, matching portions of the connecting member23and the elastic element24are approximately conical, and the two clamping portions242incline outwards relative to the middle line located between the two clamping portions242. In some embodiments, each clamping portion242inclines outwards relative to the middle line by 4°. Each of the two clamping portions242has a free end formed at a side away from the connecting portion241. The free ends are bent and extended toward with each other to form limiting hooks2424, recesses233are correspondingly formed in the connecting member23, and the limiting hooks2424are slidably disposed in the recesses233. Due to the clamping portions242are limited in the space between the inner wall of the brush head body21and the connecting member23in the radial direction of the driving shaft11, when the abutting arches2423deform elastically, the limiting hooks2424will slide vertically in the recesses233in the axial direction of the slot231.

An end, close to the bristles22, of the connecting member23is provided with two limiting blocks234which are arranged in a spaced manner in the axial direction of the slot231, and the through openings232are located between the limiting blocks234. The connecting portion241is clamped between the top end, of the limiting block234close to the bristles22and the inner wall of the brush head body21, the two clamping portions242are located at two opposite sides of the limiting blocks234, respectively, and the abutting arches2423correspond to the through openings232in position and are bent into the through openings232. Each limiting block234has two limiting portions2341which are symmetrically arranged left and right along the axial direction of the slot231, the slot231extends from one end of the connecting member23into the limiting block234close to the bristles22, and the two clamping portions242abut against the two symmetrical limiting portions2341, so that the two sides of the driving shaft11are stressed uniformly.

When the brush head2and the handle1are assembled together, the driving shaft11is inserted into the slot231from the bottom of one end of the connecting member23, penetrates through one limiting block234and is then inserted into the limiting block234close to the bristles22. The two limiting blocks234are arranged one above the other in the axial direction of the slot231, so that the stability of the driving shaft11can be further enhanced, and abnormal swinging of the driving shaft11in the radial direction is avoided. A gap between the driving shaft11and the inner wall of the slot231of the limiting block234is preferably 0.02 mm. If the gap is too large, the driving shaft11will swing in the slot231.

In addition, the mounting position of the outer surface of the connecting member23corresponding to the elastic element24is formed with a concave mounting groove235, wherein the depth of the mounting groove235corresponding to the clamping portions242is smaller than the thickness of the clamping portions242, so that after the connecting member23is assembled on the brush head body21, the inner wall of the brush head body21can clamp/grasp the two clamping portions242of the elastic element24to thereby provide a rebound force for the two abutting arches2423. In this embodiment, surfaces2425of the clamping portions242protrude out of the surface of the connecting member23by a thickness of 0.01 mm-0.3 mm. In addition, a gap between the surface, corresponding to the two clamping portions242, of the connecting member23and the inner wall of the brush head body21is 1 mm-1.8 mm; if the gap is too small, the driving shaft11cannot be inserted into the slot231; and if the gap is too large, the rebound force provided by the inner wall of the brush head body21will be insufficient, which in turn leads to unstable clamping. In this embodiment, the gap between the surface, corresponding to the two clamping portions242, of the connecting member23and the inner wall of the brush head body11is 1.3 mm.

One of the two opposite outer walls of the connecting member23is a plane236, and the other one is an arc surface. Such an asymmetric design can prevent mistaken alignment when the connecting member23and the brush head body11are assembled.

To ensure that the elastic element24and the connecting member23are assembled in place, portions, close to the two ends of the two abutting arches2423, of the limiting portions2341are slopes2342, and the two ends of the two abutting arches2423abut against the corresponding slopes2342, so that the abutting arches2423are sustained by the slopes2342and the two ends of the abutting arches2423are prevented from being suspended.

As shown inFIG. 4, a distance between the vertex end of one of the clamping portions242and a central axis of the slot231is equal to a distance between the vertex end of the other of the clamping portions and the central axis of the slot, and the two clamping portions242are symmetrical or asymmetrical in shape with respect to the central axis of the slot231. In this embodiment, the two clamping portions242are asymmetric in shape with respect to the central axis of the slot231, the vertex end of the abutting arch2423of one abutting portion242is a plane to enlarge the contact area between the clamping portion242and the driving shaft11, and the vertex end of the abutting arch2423of the other clamping portion242is an arc surface. The plane of the top end of the abutting arch2423is further formed with a plurality of parallel grooves2426, so that a plurality of concave-convex structures are formed in the abutting arch2423; and correspondingly, as shown inFIG. 7, the surface, in contact with the plane of the abutting arch2423, of the driving shaft11is also a plane111which is provided with a plurality of similar concave-convex structures112. Through the cooperation of the concave-convex structures2426and112on the abutting arch2423and the driving shaft11, the contact tightness of the driving shaft11and the elastic element24can be enhanced, and the anti-slip effect is improved. It can be understood that the two clamping portions in the embodiments of the invention are not limited to the above form, and may be also in other forms. For example, the vertex ends of the abutting arches of the two clamping portions both are flat surfaces or arc surfaces. Moreover, the plane of the vertex end of the abutting arch in this embodiment is not limited to a plane with the grooves form mentioned above, and may also be in other forms as long as the plane can meet the roughness requirement and can improve the friction. In addition, as shown inFIG. 5, a coating243for lowering noises and improving wear resistance is disposed on the outer surface of the elastic element24, and the coating may be made of rubber oil.

In this embodiment, due to the distance between the vertexes of the two abutting arches2423is smaller than the radial thickness of the driving shaft11when the abutting arches2423are not stressed, namely when the handle1and the brush head2are not assembled, the driving shaft11will apply an outward expansion force to the clamping portions242after assembly to cause the abutting arches2423to deform, and the inner wall of the brush head body21forces the abutting arches2423to rebound, so that the two clamping portions242tightly clamp/grasp the driving shaft11from both sides of the driving shaft11. The brush head2is simple in structure. The driving shaft11is firmly clamped by the elastic element24so that the brush head2and the driving shaft11are connected stably.

The above embodiments are merely preferred ones of the invention, and are not intended to limit the invention. All variations, modification, substitutions, combinations and simplifications made without departing from the spirit and principle of the invention should be construed as equivalents of the invention and should also fall within the protection scope of the invention.