Toothbrush head for electric toothbrush

Abstract

The present invention provides a toothbrush head for an electric toothbrush. The toothbrush head comprises: a handle rod portion, the handle rod portion having a proximal end and a distal end, and the distal end being configured to connect to a handle body of the electric toothbrush; a brush plate, the brush plate being rotatably disposed at the proximal end of the handle rod portion; and a rocker, the rocker being disposed within the handle rod portion, and a proximal end of the rocker being connected to the brush plate to drive the brush plate to perform reciprocating rotation. The toothbrush head further comprises a magnetic coupling assembly and an elastic member. The magnetic coupling assembly comprises a magnetic coupling flux guide and a brush head permanent magnet, the magnetic coupling flux guide having a first acting surface and a second acting surface, the first acting surface facing the distal end of the handle rod portion, and the second acting surface being arranged opposite a pole surface of the brush head permanent magnet with a certain gap therebetween. The magnetic coupling flux guide is fixedly connected to the handle rod portion, the brush head permanent magnet is fixedly connected to the rocker, and the elastic member is disposed to provide an elastic force between the handle rod portion and the rocker. The toothbrush head of the present invention effectively improves noise and vibration during the use of the electric toothbrush and reduces energy loss.

Description

Toothbrush heads for electric toothbrushes Technical Field

[0001] This invention relates to the technical field of personal care devices, and more specifically, to toothbrush heads for electric toothbrushes. Background Technology

[0002] Currently, there are various types of electric toothbrushes on the market, including drive devices for reciprocating motion. These drive devices are connected to external cleaning or operating components to achieve the corresponding actions.

[0003] There is currently a type of electric toothbrush in which a permanent magnet is installed on the drive shaft of the handle body. When the toothbrush head is installed on the handle body, the permanent magnet of the drive shaft of the handle body is connected to the moving parts inside the toothbrush head through magnetic attraction. As the drive device inside the handle body moves back and forth linearly, it drives the brush plate at the near end of the toothbrush head to rotate back and forth.

[0004] However, in this type of electric toothbrush, the drive shaft of the handle body and the moving parts of the brush head are directly mechanically connected. When the drive shaft of the handle body moves at high speed, there is often a slight periodic relative movement at the connection point. This relative movement causes energy loss and high-frequency noise.

[0005] As consumers increasingly demand higher quality electric toothbrushes, they expect improvements in reducing high-frequency noise and vibration during use, and also hope to further reduce energy consumption. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a toothbrush head for an electric toothbrush, the toothbrush head comprising: a handle portion having a proximal end and a distal end, the distal end being configured to connect to the handle body of the electric toothbrush; a brush disc rotatably disposed at the proximal end of the handle portion; and a swing arm disposed within the handle portion, the swing arm reciprocating about a rotation axis, the proximal end of the swing arm being connected to the brush disc to drive the brush disc to reciprocate; wherein the toothbrush head further comprises a magnetic coupling assembly and an elastic element, the magnetic coupling assembly comprising a magnetic coupling conductor and a brush head permanent magnet, wherein the magnetic coupling conductor has a first working surface and a second working surface, the first working surface and the second working surface are not coplanar, the first working surface faces the distal end of the handle portion, while the second working surface is arranged opposite to the magnetic pole surface of the brush head permanent magnet at a distance of a gap, wherein the magnetic coupling conductor is fixedly connected to the handle portion, the brush head permanent magnet is fixedly connected to the swing arm, and the elastic element is configured to provide an elastic force between the handle portion and the swing arm.

[0007] According to one aspect of the invention, the magnetically connected magnetic conductor is formed by stacking and bending take-off magnetic material sheets, the first working surface and the second working surface are stacked end faces exposing the ends of a plurality of take-off magnetic material sheets, the second working surface is closer to the proximal end of the handle portion than the first working surface; the second working surface is not aligned with the first working surface in the axial direction, and the second working surface is radially further away from the rotation axis than the first working surface.

[0008] According to another aspect of the invention, the brush head permanent magnet includes a first brush head permanent magnet and a second brush head permanent magnet, which are disposed separately on the rear end of the swing arm about the rotation axis of the swing arm. The magnetic connection assembly includes two second working surfaces facing the first brush head permanent magnet and the second brush head permanent magnet, respectively. Each of the first brush head permanent magnet and the second brush head permanent magnet includes a pair of magnetic pole faces opposite to the second working surfaces. The first brush head permanent magnet and the second brush head permanent magnet are symmetrically arranged about the swing midpoint plane containing the swing arm.

[0009] According to another aspect of the present invention, the first brush head permanent magnet and the second brush head permanent magnet each include two permanent magnet portions disposed adjacent to each other, the magnetic pole surfaces of the two permanent magnet portions being opposite to the second working surface in an axial or radial direction, and the polarities of the magnetic pole surfaces of the two permanent magnet portions being opposite.

[0010] According to another aspect of the invention, the magnetic pole faces of two adjacent permanent magnet portions facing away from the second working surface are connected by a shorting conductor, which is fixed to the rocker arm by an embedded molding process.

[0011] According to another aspect of the invention, a first recess and a second recess are formed at the proximal end of the magnetically connected magnetic conductor, and a second working surface is formed on the inner surface of each of the first and second recesses. The paired magnetic pole faces of each of the first and second brush head permanent magnets are two circumferentially opposite surfaces of the same brush head permanent magnet. The first and second brush head permanent magnets are respectively partially received in the first and second recesses, and the second working surface is opposite to the magnetic pole faces of the first and second brush head permanent magnets in the circumferential direction.

[0012] According to another aspect of the invention, the rear end of the swing arm has a hollow portion and an open sleeve portion, and a brush head permanent magnet is disposed in the sleeve portion, with the magnetic pole surface of the brush head permanent magnet opposite to the second working surface protruding from the surface of the sleeve portion.

[0013] According to another aspect of the invention, the elastic element is a torsion spring, which is disposed in the hollow part of the sleeve portion. A slot is provided on the side wall of the sleeve portion. The first fixed end of the torsion spring is fixed to the slot, and the second fixed end of the torsion spring is fixed to the handle portion.

[0014] According to another aspect of the invention, the handle portion includes a housing and a bushing disposed inside the rear end of the housing. The bushing has a hollow portion, and a magnetically connected magnetic conductor is held by the bushing. A first working surface of the magnetically connected magnetic conductor is exposed in the hollow portion of the bushing, or the first working surface of the magnetically connected magnetic conductor is embedded in the bushing material and close to the hollow portion of the bushing. A second working surface of the magnetically connected magnetic conductor is exposed outside the proximal side of the bushing, or the second working surface of the magnetically connected magnetic conductor is embedded in the bushing material and close to the proximal side of the bushing. The size of the hollow portion of the bushing is configured to accommodate a drive shaft permanent magnet of an electric toothbrush, and the first working surface faces the magnetic pole face of the drive shaft permanent magnet.

[0015] According to another aspect of the invention, the elastic element is a torsion spring, the proximal end of the bushing is provided with a boss protruding towards the proximal end, the torsion spring is sleeved on the boss, and the second fixed end of the torsion spring is fixed to the bushing.

[0016] Using the toothbrush head according to the present invention can effectively improve the noise and vibration during the use of electric toothbrushes and reduce energy consumption. Attached Figure Description

[0017] For a more complete understanding of the invention, reference can be made to the following description of exemplary embodiments taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 shows a perspective view of a toothbrush head according to the present invention.

[0019] Figure 2 shows a cross-sectional perspective view of a toothbrush head according to a first embodiment of the present invention.

[0020] Figure 3 shows a perspective view of a portion of the internal structure of a toothbrush head according to a first embodiment of the present invention.

[0021] Figure 4 shows a partial cross-sectional perspective view of the internal structure shown in Figure 3.

[0022] Figure 5 shows a schematic diagram of a portion of the structure of a toothbrush head according to a first embodiment of the present invention.

[0023] Figure 6 shows a perspective view of the magnetic coupling assembly according to a first embodiment of the present invention.

[0024] Figure 7 shows another perspective view of the magnetic coupling assembly according to the first embodiment of the present invention.

[0025] Figure 8 shows a perspective cross-sectional view of a toothbrush head according to a second embodiment of the present invention.

[0026] Figure 9 shows a perspective view of the magnetic coupling assembly according to a second embodiment of the present invention.

[0027] Figure 10 shows a perspective view of the combination of the drive shaft permanent magnet and the brush head permanent magnet according to the second embodiment of the present invention.

[0028] Figure 11 shows a perspective view of the pendulum rod according to a second embodiment of the present invention.

[0029] Figure 12 shows a perspective cross-sectional view of the pendulum rod according to a second embodiment of the present invention.

[0030] Figure 13 shows a perspective view of the motion structure of the toothbrush head according to a second embodiment of the present invention.

[0031] Figure 14 shows a perspective cross-sectional view of the motion structure of the toothbrush head according to a second embodiment of the present invention.

[0032] Figure 15 shows a perspective view of the oscillating arm and magnetic connection assembly of a toothbrush head according to a third embodiment of the present invention.

[0033] Figure 16 shows a perspective sectional view of the lever and connecting assembly of the toothbrush head according to a third embodiment of the present invention.

[0034] Figure 17 shows another perspective sectional view of the motion structure of the toothbrush head according to a third embodiment of the present invention.

[0035] List of reference numerals: 1, 1' toothbrush head; 10 handle; 11 outer shell; 125 positioning shaft; 12 bushing; 121 boss; 122 proximal end wall; 20 brush disc; 30, 30', 30" swing arm; 31, 31', 31" sleeve; 32 slot; 40, 40', 40" torsion spring; 41 first fixed end; 42 second fixed end; 58, 58" shorting magnet; 50, 50', 50" brush head permanent magnet; 60, 60', 60" magnetic connection magnet; 61, 61', 61" first working surface; 62, 62', 62" second working surface; 70 drive shaft permanent magnet; F1, F2 magnetic force; L1 rotation axis; L2 brush disc axis. Detailed Implementation

[0036] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0037] In the following description, "proximal / proximal end" refers to the side or end of the brush plate 20 near the toothbrush head 1, while "distal / distal end" refers to the side or end of the brush plate 20 away from the toothbrush head 1. "Axial" refers to the direction of extension of the rotation axis L1 of the swing arm 30 of the toothbrush head 1, "radial" refers to the radial direction relative to the rotation axis L1 of the swing arm 30 of the toothbrush head 1, and "circumferential" refers to the circumferential direction around the rotation axis L1 of the swing arm 30.

[0038] Figure 1 shows the outline of a toothbrush head 1 suitable for an electric toothbrush according to the present invention. The toothbrush head 1 is mounted to the handle body of the electric toothbrush during use. The handle body of the electric toothbrush includes a drive shaft with a drive shaft permanent magnet 70 (see Figure 8) at its proximal end. The drive shaft drives the drive shaft permanent magnet to perform reciprocating linear motion.

[0039] As shown in Figure 1, the toothbrush head 1 includes a handle portion 10, with a brush disc 20 movably connected to the proximal end of the handle portion 10. A moving component is provided inside the handle portion 10, and the brush disc 20 of the toothbrush head 1 reciprocates around the brush disc axis L2 of the brush disc 20 under the actuation of the moving component. A connecting device is provided at the distal end of the handle portion 10 for detachably connecting the toothbrush head 1 to a matching connecting device on the handle body; for example, the connecting device is a rotary snap-fit ​​device.

[0040] Figures 2 to 7 illustrate a first embodiment of the toothbrush head 1 according to the present invention. As shown in Figure 2, the moving parts within the handle portion 10 mainly include a rocker arm 30, an elastic element, and a magnetic coupling assembly. The rocker arm 30 is disposed within the handle portion 10, and the handle portion 10 and the rocker arm 30 are respectively provided with a positioning shaft 125 and a positioning shaft hole for receiving the positioning shaft 125. The positioning shaft 125 is rotatably fitted in the positioning shaft hole, and the rotation axis L1 extends through the positioning shaft 125. The magnetic coupling assembly is configured to transfer the driving force from the drive shaft of the electric toothbrush, and in conjunction with the elastic element, realizes the oscillating force of the rocker arm 30 oscillating about the rotation axis L1. Specifically, as shown in Figure 7, the magnetic connection assembly mainly includes a magnetic connection conductor 60 and a brush head permanent magnet 50. The magnetic connection conductor 60 guides the magnetic field from the drive shaft permanent magnet 70, so that it is superimposed with the magnetic field generated by the brush head permanent magnet 50 in the magnetic connection assembly. As the drive shaft permanent magnet 70 reciprocates, the magnetic induction intensity of the magnetic field from the drive shaft permanent magnet 70 and guided by the magnetic connection conductor 60 is in an alternating state. The two superimposed magnetic fields generate an alternating magnetic force on the brush head permanent magnet 50. The alternating magnetic force and the elastic force generated by the elastic element combine to drive the swing arm 30 to swing back and forth around the axis L1.

[0041] In the first embodiment, the magnetic coupling conductor 60 is fixedly connected to the handle portion 10, while the brush head permanent magnet 50 is fixedly connected to the swing arm 30. The magnetic coupling conductor 60 forms two working surfaces: a first working surface 61 and a second working surface 62 (see Figures 3 and 4), wherein the first working surface 61 is the surface opposite to the proximal magnetic pole surface of the drive shaft permanent magnet 70 of the electric toothbrush, and the second working surface 62 is the surface facing the magnetic pole surface of the brush head permanent magnet 50.

[0042] Specifically, in the first embodiment, as shown in FIG6, the magnetically connected magnetic conductor 60 is formed by combining two magnetic conductor portions that are symmetrical about a plane parallel to the axis. Preferably, each magnetic conductor portion is formed by stacking multiple sheets of take-off magnetic material and bending them at two right angles. The stacked end faces of the multiple sheets of take-off magnetic material at opposite ends form a first working surface 61 and a second working surface 62. The first working surfaces 61 of each magnetic conductor portion are arranged adjacently on the same radial plane. The second working surfaces 62 of each magnetic conductor portion are separated by a distance and arranged on another radial plane, and the second working surfaces 62 of each magnetic conductor portion face the corresponding brush head permanent magnet 50 through a small axial gap.

[0043] The arrangement of the brush head permanent magnets 50 is clearly seen in Figure 5. The brush head permanent magnets 50 include a first brush head permanent magnet and a second brush head permanent magnet, which are symmetrically arranged about the swing midpoint plane of the swing arm 30, including the rotation axis L1. The first and second brush head permanent magnets are arranged in pairs, that is, each of the first and second brush head permanent magnets includes two adjacent permanent magnet portions or blocks, whose magnetic poles on the opposite second working surface 62 have opposite polarities, one being the S pole and the other the N pole. The two opposing magnetic poles are coplanar; preferably, the two magnetic poles have the same size and shape, thereby generating a magnetic flux of essentially the same magnitude but opposite direction. Meanwhile, as shown in Figure 6, each pair of permanent magnet portions is connected at their opposite magnetic poles on the second working surface 62 by a short-circuit conductor 58, as shown in Figure 7.

[0044] In the first embodiment, the magnetic coupling conductor 60 and the brush head permanent magnet 50 in the magnetic coupling assembly are held by the handle portion 10 and the swing arm 30 of the toothbrush head 1, respectively.

[0045] As shown in Figure 2, the handle portion 10 of the toothbrush head 1 includes a housing 11 and a bushing 12. The bushing 12 is inserted into the hollow portion of the housing 11 through a distal opening. The outer contour of the bushing 12 matches the shape of the inner wall space of the rear end portion of the housing 11. Preferably, the bushing 12 is snapped into the housing 11. Preferably, the magnetically connected magnetic conductor 60 is fixed in the proximal end wall portion 122 of the bushing 12 by an embedded molding method. The first working surface 61 of the magnetically connected magnetic conductor 60 is exposed in the hollow portion of the bushing 12, while the second working surface 62 is exposed outside the bushing 12. The first working surface 61 and the second working surface 62 are not directly opposite or aligned along the rotation axis L1, that is, the second working surface 62 is radially further away from the rotation axis L1 relative to the first working surface 61.

[0046] Obviously, the first embodiment can be modified as follows without affecting the implementation of the present invention. The first working surface 61 of the magnetic coupling conductor 60 may be embedded in the material of the bushing 12 (e.g., the first working surface is covered by the plastic material of the bushing 12) and close to the hollow portion of the bushing 12. Similarly, the second working surface 62 may be embedded in the material of the bushing 12 and close to the proximal end of the bushing 12. The first working surface 61 and the second working surface 62 of the magnetic coupling conductor 60 are spaced apart along the rotation axis L1. The first working surface 61 and the second working surface 62 are opposite or aligned along the rotation axis L1, that is, the second working surface 62 and the first working surface 61 are formed by two opposite surfaces of the magnetic coupling conductor extending along the rotation axis L1.

[0047] When the toothbrush head 1 is installed onto the handle body of the electric toothbrush, the drive shaft permanent magnet 70 of the handle body can be inserted into the hollow part of the bushing 12, and the magnetic pole surface of the drive shaft permanent magnet 70 is opposite to the first working surface 61 of the magnetically connected magnetic conductor 60. During use, the drive shaft permanent magnet 70 reciprocates axially relative to the handle part 10 in the hollow part of the bushing 12, while the magnetically connected magnetic conductor 60 is stationary relative to the handle part 10. In other words, the drive shaft permanent magnet 70 reciprocates linearly along the axis relative to the magnetically connected magnetic conductor 60 in the hollow part of the bushing 12.

[0048] To hold the brush head permanent magnet 50, as shown in Figure 5, the rear end of the swing arm 30 forms a cylindrical sleeve portion 31 with a diameter larger than the rest of the swing arm 30. The sleeve portion 31 has a hollow interior and an open rear end. Two pairs of brush head permanent magnets 50 protrude from the annular ends of the sleeve portion 31. The swing arm 30 is typically made of plastic. For ease of manufacturing, the brush head permanent magnets 50 and the shorting conductors 58 are formed in the swing arm 30 by an embedded molding method, making the brush head permanent magnets 50, the shorting conductors 58, and the swing arm a single piece. A boss 121 protruding axially is provided on the proximal end wall of the bushing 12. This boss 121 is inserted into the sleeve portion 31, as shown in Figure 2. Alternatively, the shorting magnet 58 can also be formed in the swing arm 30 by an embedded molding method, and the brush head permanent magnet 50 can be glued to the shorting magnet 58, so that the brush head permanent magnet 50, the shorting magnet 58 and the swing arm are made into a single piece.

[0049] On the other hand, as shown in Figures 4 and 6, the elastic element is a torsion spring 40, which is housed in the hollow portion of the sleeve portion 31 of the rocker arm 30 and fitted onto the boss 121 of the bushing 12. As shown in Figure 5, an axially extending slot 32 is formed in the side wall of the sleeve portion 31. The first fixed end 41 of the torsion spring 40 is engaged in the slot 32, thereby fixing the first fixed end 41 to the rocker arm 30. The second fixed end 42 of the torsion spring 40 is inserted into a socket formed near the boss 121 of the bushing 12, so that the second fixed end 42 of the torsion spring 40 is fixed by the bushing 12 and correspondingly forms a fixed connection with the handle portion 10. In this way, the torsion spring 40 can provide a reciprocating force for the reciprocating swing of the rocker arm 30 relative to the handle portion 10.

[0050] After the toothbrush head 1 of the first embodiment of the present invention is connected to the handle body, the brush plate 20 can achieve reciprocating rotational motion as the drive shaft of the handle body moves linearly in the reciprocating direction. Specifically, the magnetic pole surface of the drive shaft permanent magnet 70 is directly opposite the first working surface 61 of the magnetic connecting magnetic conductor 60. The magnetic field energy of the drive shaft permanent magnet 70 is guided through the magnetic connecting magnetic conductor 60 to the second working surface 62 opposite to the brush head permanent magnet 50. The magnetic field flowing out from the second working surface 62 is superimposed with the magnetic field of the brush head permanent magnet 50, causing the magnetic field generated by the brush head permanent magnet 50 itself to be distorted. In order to maintain the original shortest magnetic path, the magnetic field of the brush head permanent magnet 50 generates circumferential or tangential magnetic forces F1 and F2 between the second working surface 62 and the brush head permanent magnet 50, as shown in FIG5. When the drive shaft permanent magnet 70 is driven closer to the magnetically connected magnetic conductor 60, the magnetic induction intensity B from the drive shaft permanent magnet 70 increases because the magnetically connected magnetic conductor 60 is stationary. Consequently, the magnetic induction intensity flowing from the second working surface 62 of the magnetically connected magnetic conductor 60 also increases, resulting in larger magnetic forces F1 and F2. When the magnetic forces F1 and F2 increase to the point that they can overcome the resistance of the torsion spring 40, the rocker arm 30 will be pushed to rotate around the rotation axis L1. As the drive shaft permanent magnet 70 is driven away from the magnetically connected magnetic conductor 60, the magnetic induction intensity flowing from the second working surface 62 of the magnetically connected magnetic conductor 60 decreases, and the magnetic forces F1 and F2 generated between the second working surface 62 and the brush head permanent magnet 50 also decrease accordingly. When the magnetic forces F1 and F2 are less than the elastic force of the torsion spring 40, the torsion spring 40 releases its potential energy, pushing the rocker arm 30 to rotate around the rotation axis L1. Thus, as the permanent magnet 70 of the drive shaft reciprocates, the magnetic induction intensity B from the permanent magnet 70 of the drive shaft and the magnetic induction intensity flowing out from the second working surface 62 of the magnetic connector 60 alternately change, and the magnetic forces F1 and F2 alternately change. Under the action of the changing magnetic forces F1 and F2 and the elastic force of the torsion spring 40, the rocker arm 30 realizes reciprocating rotation around the rotation axis L1.

[0051] During the movement of the drive shaft permanent magnet 70 inside the handle 10, the drive shaft permanent magnet 70 does not directly contact the magnetically connected magnetic conductor 60. Therefore, the noise and vibration of the electric toothbrush are effectively improved, and energy loss is reduced.

[0052] Figures 9 to 14 show a toothbrush head 1' according to a second embodiment of the present invention. Unlike the arrangement in the first embodiment where the second working surface of the magnetically connected magnetic conductor 60 and the magnetic pole face of the brush head permanent magnet 50 are axially opposite each other, in the second embodiment, the second working surface 62' of the magnetically connected magnetic conductor 60' and the magnetic pole face of the brush head permanent magnet 50' are circumferentially opposite each other with a gap between them. Thus, in the second embodiment, the magnetically connected magnetic conductor 60' guides the magnetic flux from the drive shaft permanent magnet 70 to be perpendicular to the rotation axis L1 and along the circumferential direction. As shown in Figure 10, the second working surface 62' of the magnetically connected magnetic conductor 60' forms a plurality of magnetic poles (N') corresponding to the drive shaft permanent magnet 70.

[0053] As shown in Figure 13, in the second embodiment, the brush head permanent magnet 50' of the magnetic connection assembly includes two independent brush head permanent magnets 50'. The two permanent magnets 50' are symmetrically arranged on the end of the sleeve portion 31' of the swing rod 30' around the swing mid-position plane (the "swing mid-position plane" is generally located at the middle position of the swing rod in the swing range and passes through the axis L2 of the rotation shaft) and protrude from the rear end face. The surface of the two brush head permanent magnets 50' that is perpendicular to the rear end face of the sleeve portion 31' and faces the second working surface 62' of the magnetic connection conductor 60' is a magnetic pole surface, with one side surface being the S pole and the other side surface being the N pole.

[0054] On the other hand, two recesses are formed near the proximal end of the magnetically connected magnetic conductor 60', and the brush head permanent magnet 50' is received in each recess. The side surface of each recess is opposite to the magnetic pole face of the side of the brush head permanent magnet 50', thereby forming a second working surface 62'. As shown in Figures 10 and 13, the magnetically connected magnetic conductor 60' is formed by stacking and bending layers of magnetically conductive material sheets. Its first working surface 61' and second working surface 62' are also the stacked end faces of the material sheets, that is, the end face includes the end face of each layer of magnetically conductive material sheet. The first working surface 61' of the magnetically connected magnetic conductor 60' is the same as that in the first embodiment. In the second embodiment, the first working surface 61' and the second working surface 62' are not directly opposite or aligned with each other in the axial direction. They are in intersecting planes. The first working surface 61' is in a plane perpendicular to the rotation axis L1, while the second working surface 62' is in a plane approximately radial to the rotation axis L1.

[0055] The structure of the rocker arm 30', bushing 12' and torsion spring 40' in the second embodiment is similar to that in the first embodiment, and will not be described again here.

[0056] As the distance between the permanent magnet 70 of the drive shaft and the magnetic conductor 60' changes back and forth, the magnetic induction intensity from the permanent magnet 70 of the drive shaft guided by the magnetic conductor 60' increases or decreases accordingly, causing the magnetic force generated by the interaction with the permanent magnet 50' of the brush head to increase or decrease. Under the action of the elastic force of the torsion spring 40', the swing arm 30' reciprocates around the rotation axis.

[0057] Figures 15 to 17 illustrate a toothbrush head according to a third embodiment of the present invention. In the third embodiment, the second working surface 62” of the magnetic coupling magnetic conductor 60” and the magnetic pole surface of the brush head permanent magnet 50” are arranged opposite each other in the radial direction with a gap between them. In this way, the magnetic coupling magnetic conductor 60” guides the magnetic lines of force from the drive shaft permanent magnet 70” in a radial direction perpendicular to the rotation axis L1. The first working surface 61” and the second working surface 62” are not directly opposite or aligned with each other in the axial direction, and the planes in which they lie intersect each other.

[0058] As shown in Figures 16 and 17, a first brush head permanent magnet and a second brush head permanent magnet are separately disposed at the rear end of the sleeve portion 31” of the swing arm 30”. Each brush head permanent magnet 50” includes two adjacent permanent magnet portions or blocks. The inner circumferential surface of the brush head permanent magnet 50” around the axial direction is a magnetic pole surface, one of which is the N pole and the other is the S pole. As shown in Figure 16, the magnetic connecting magnetic conductor 60” is formed by bending two sets of magnetic conductive materials into an L shape and then splicing them together. The outer surface of the front end of the magnetic connecting magnetic conductor 60” is a stacked end face, which constitutes the second working surface 62”, which is radially spaced from the magnetic pole surface of the inner circumferential surface of each pair of brush head permanent magnets 50” by a gap.

[0059] Preferably, both the second working surface 62” and the inner circumferential surface of the brush head permanent magnet 50” are arc-shaped surfaces, so that the second working surface 62” is substantially parallel to the magnetic pole surface of the brush head permanent magnet 50”, maintaining a uniform gap. The first working surface 61” of the magnetic coupling conductor 60” is a radially extending plane, which is also disposed inside the bushing.

[0060] Furthermore, a shorting conductor 58” is provided on the radial outer side of the brush head permanent magnet 50”, so that the magnetic circuits of the magnetic pole portions of the paired brush head permanent magnets 50” facing away from the second working surface are shorted. The shorting conductor 58 can be embedded in the rear sleeve portion 31” of the swing arm 30”, while the brush head permanent magnet 50” is fixed to the inner periphery of the shorting conductor 58”.

[0061] The structure and connection method of the rocker arm 30”, bushing and torsion spring 40” in the third embodiment are similar to those in the first embodiment, and will not be described again here.

[0062] In the above embodiments, a first brush head permanent magnet and a second brush head permanent magnet are respectively provided on the swing arms 30, 30', and 30" respectively. Each of them provides a set of opposite magnetic pole surfaces, namely an S pole surface and an N pole surface, opposite to the second working surface of the magnetically connected magnetic conductor 60. This set of magnetic pole surfaces can be provided by two permanent magnets or by two opposing surfaces of a single permanent magnet. Preferably, the first brush head permanent magnet and the second brush head permanent magnet are symmetrically arranged about the swing midpoint plane containing the rotation axis L1 of the swing arm 30.

[0063] After the toothbrush head 1 according to the invention is connected to the handle body having a drive shaft permanent magnet, as the drive shaft permanent magnet 70 moves relative to the magnetically connected magnetic conductors 60, 60', 60" respectively, the magnetic force generated between the second working surface of the magnetically connected magnetic conductor and the brush head permanent magnet changes alternately in the circumferential direction relative to the rotation axis L1. The torsion spring should be appropriately selected so that the maximum magnetic force F1, F2 generated between the second working surface of the magnetically connected magnetic conductor and the brush head permanent magnet is greater than the initial resistance of the elastic element, causing the swing arm 30 to swing. At the same time, the elastic force generated by the deformation of the elastic element is greater than the minimum magnetic force generated between the second working surface of the magnetically connected magnetic conductors 60, 60', 60" and the brush head permanent magnets 50, 50', 50" respectively, thereby realizing the reciprocating rotation of the swing arm 30, 30', 30" around the rotation axis L1.

[0064] In the above embodiments, the magnetically connected magnetic conductors 60, 60', and 60" are preferably made by stacking and bending take-off magnetic material sheets. Preferably, the magnetically connected magnetic conductors 60, 60', and 60" are also symmetrically arranged about the swing midpoint plane containing the rotation axis L1 of the swing rod 30. The take-off magnetic material sheets can be grain-oriented silicon steel sheets or grain-oriented silicon steel sheets. The easily magnetizable grains of the take-off magnetic material sheets are distributed along the rolling direction, with high magnetic field induction intensity and low magnetic reluctance in the rolling direction. The magnetic reluctance increases in the non-rolling direction, thus making it easier for magnetic lines of force to concentrate and flow along the rolling direction of the grain-oriented silicon steel sheets.

[0065] In other alternative embodiments, the magnetic coupling conductor can also be made of stacked non-oriented magnetic material sheets, with non-oriented silicon steel sheets having similar magnetic resistance in all directions.

[0066] While the invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the invention.

Claims

1. A toothbrush head for an electric toothbrush, the toothbrush head comprising: The handle portion has a proximal end and a distal end, the distal end being configured to connect to the handle body of the electric toothbrush; A brush disc, which is rotatably disposed at the proximal end of the handle portion; as well as A swing arm is disposed inside the handle portion and swings back and forth about a rotation axis. The proximal end of the swing arm is connected to the brush disk to drive the brush disk to rotate back and forth. Its features are, The toothbrush head also includes a magnetic connection assembly and an elastic element. The magnetic coupling assembly includes a magnetic coupling conductor and a brush head permanent magnet. The magnetic coupling conductor has a first working surface and a second working surface, which are not coplanar. The first working surface faces the distal end of the handle portion, while the second working surface is arranged opposite to the magnetic pole face of the brush head permanent magnet at a distance from it. The magnetic coupling conductor is fixedly connected to the handle portion, and the brush head permanent magnet is fixedly connected to the swing arm. The elastic element is configured to provide an elastic force between the handle portion and the rocker arm.

2. The toothbrush head as described in claim 1, characterized in that, The magnetically connected magnetic conductor is formed by stacking and bending layers of take-off magnetic material sheets. The first functional surface and the second functional surface are stacked end faces that expose the ends of multiple take-off magnetic material sheets. The second working surface is closer to the proximal end of the handle portion than the first working surface; The second working surface is not aligned with the first working surface in the axial direction, and the second working surface is radially further away from the axis of rotation than the first working surface.

3. The toothbrush head as described in claim 1, characterized in that, The brush head permanent magnet includes a first brush head permanent magnet and a second brush head permanent magnet, which are separately disposed on the rear end of the swing arm around the rotation axis of the swing arm. The magnetic connection assembly includes two second working surfaces that are respectively facing the first brush head permanent magnet and the second brush head permanent magnet. Each of the first and second brush head permanent magnets includes a pair of magnetic pole faces opposite to the second working surface. The first and second brush head permanent magnets are arranged symmetrically about the swing midpoint plane containing the swing arm.

4. The toothbrush head as described in claim 3, characterized in that, The first brush head permanent magnet and the second brush head permanent magnet each include two permanent magnet parts arranged adjacent to each other. The magnetic pole surfaces of the two permanent magnet parts are opposite to the second working surface in the axial or radial direction, and the polarities of the magnetic pole surfaces of the two permanent magnet parts are opposite.

5. The toothbrush head as described in claim 4, characterized in that, The magnetic pole faces of the two adjacent permanent magnets that are away from the second working surface are connected by a short-circuit magnetic conductor, which is fixed to the rocker arm by embedding molding.

6. The toothbrush head as described in claim 3, characterized in that, The proximal end of the magnetically connected conductor forms a first recess and a second recess, and the inner surface of each of the first and second recesses forms a second working surface. The paired magnetic pole faces of each of the first and second brush head permanent magnets are two circumferentially opposite surfaces of the same brush head permanent magnet. The first brush head permanent magnet and the second brush head permanent magnet are respectively partially received in the first recess and the second recess, and the second working surface is opposite to the magnetic pole surface of the first brush head permanent magnet and the second brush head permanent magnet in the circumferential direction.

7. The toothbrush head as described in claim 3, characterized in that, The rear end of the swing arm has a hollow portion and an open sleeve portion, and the permanent magnet of the brush head is disposed in the sleeve portion. The magnetic pole face of the permanent magnet of the brush head, which is opposite to the second working surface, protrudes from the surface of the sleeve portion.

8. The toothbrush head as described in claim 7, characterized in that, The elastic element is a torsion spring, which is disposed in the hollow portion of the sleeve. A slot is provided on the side wall of the sleeve portion, the first fixed end of the torsion spring is fixed to the slot, and the second fixed end of the torsion spring is fixed to the handle portion.

9. The toothbrush head as described in claim 1, characterized in that, The handle portion includes a housing and a bushing disposed inside the rear end of the housing. The bushing has a hollow portion, and the magnetically connected conductor is held by the bushing. The first functional surface of the magnetic connector is exposed in the hollow portion of the bushing, or the first functional surface of the magnetic connector is embedded in the bushing material and close to the hollow portion of the bushing. The second functional surface of the magnetic coupling conductor is exposed outside the proximal side of the bushing, or the second functional surface of the magnetic coupling conductor is embedded in the bushing material and close to the proximal side of the bushing. The size of the hollow portion of the bushing is configured to accommodate the permanent magnet of the drive shaft of the electric toothbrush, and the first working surface faces the magnetic pole face of the permanent magnet of the drive shaft.

10. The toothbrush head as described in claim 9, characterized in that, The elastic element is a torsion spring. The proximal end of the bushing is provided with a boss protruding towards the proximal end. The torsion spring is sleeved on the boss, and the second fixed end of the torsion spring is fixed to the bushing.

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