Replacement brush heads for electric toothbrushes and electric toothbrushes

Abstract

To provide a replacement brush for an electric toothbrush and an electric toothbrush that can suppress rattling and improve durability. [Solution] The electric toothbrush comprises a toothbrush body and a replacement brush 14 for the electric toothbrush. The replacement brush 14 comprises a driving member 40, driven members 42, 44, and a brush housing 50. The brush housing has driven arc surfaces 66, 68 centered on the rotation center of the driven members. Driven filaments 46, 48 are implanted in the first region of the driven members 42, 44, and driven contact surfaces 112, 124 are formed in the second region that slidably contact the driven arc surface. In the third region located between the first and second regions, driven gear portions 114, 126 are formed, having driven teeth 114a, 126a that extend along the rotation axis. On the outer circumferential surface of the driving member, a driving gear portion 94 is formed, extending along the rotation axis and having driving teeth 94a that mesh with the driven teeth of one of the driven members 42.

Description

Technical Field

[0001] The present invention relates to a replacement brush for an electric toothbrush attached to a toothbrush body having an electric drive unit, and an electric toothbrush including the replacement brush.

Background Art

[0002] The following Patent Document 1 describes an example of a conventional electric toothbrush. This electric toothbrush includes a handle, a connecting rod integrally formed with the handle, a brush head provided at the tip of the connecting rod, and a drive device housed inside the handle. The brush head has an outer shell, and inside the outer shell, a plurality of shafts with bristles planted thereon are arranged. Each shaft is supported by a bearing portion formed in the brush head, and gears that mesh with each other are provided at one end of each shaft. And one shaft and the drive device are connected via a transmission shaft.

[0003] According to the electric toothbrush of Patent Document 1, the driving force of the drive device can swing the bristles planted on each shaft, and dental plaque and the like attached to the teeth can be efficiently removed. However, when the bristles are pressed against the teeth, the load concentrates on the bearing portion and the shaft, so there is a risk of damage to these. Also, if the shaft deflects due to the load, the axial distance between the gears may vary, and there is a risk of abnormal wear and rattling of the gears.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] The present invention has been made to address the above problems, and an object thereof is to provide a replacement brush for an electric toothbrush and an electric toothbrush that can suppress rattling and improve durability.

[0006] To achieve the above objective, the replacement brush for an electric toothbrush according to the present invention is characterized by being a replacement brush for an electric toothbrush that is attached to a toothbrush body having an electric drive unit, a drive shaft that is rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, comprising: a driving member that is rotated by a rotational force applied from the drive shaft, at least one driven member that is rotated by a rotational force applied from the driving member, a brush housing that has a housing space for housing the driving member and the driven member in a state where their rotational axes are parallel and is detachably connected to the main body housing, and a plurality of linear driven filaments provided on the driven member, and the brush housing The gear has an opening that opens the housing space to the outside and a driven arc surface centered on the rotation center of the driven member, the driven filament is implanted in a first region on the outer circumferential surface of the driven member on the opening side, the driven contact surface is formed in a second region on the outer circumferential surface of the driven member located on the opposite side of the first region and is slidably in contact with the driven arc surface, the driven gear portion having at least one driven tooth extending along the rotation axis direction is formed in a third region on the outer circumferential surface of the driven member and is located between the first and second regions, the driven gear portion having at least one driven tooth extending along the rotation axis direction and meshing with the driven tooth is formed on the outer circumferential surface of the driven member Furthermore, the driven member is provided with protruding detachment prevention portions at both ends in the direction of the rotation axis, and the brush housing has a stopper portion facing the detachment prevention portion from the opening side. It is about that.

[0007] With this replacement brush for electric toothbrushes, when the driven filament is pressed against the tooth, the external force (load) applied to the driven member can be distributed and received by the arcuate surface, thereby suppressing rattle of the driven member and improving durability. In addition, since gaps are less likely to occur between the driven contact surface of the driven member and the driven arcuate surface of the brush housing, the entire replacement brush for electric toothbrushes can be made compact. Furthermore, since the driven gear part is formed on the driven member and the driving gear part is formed on the driving member, there is no need to prepare these gear parts as separate components, which reduces manufacturing costs and the number of assembly steps.

[0008] Also Because the driven contact surface slides smoothly while making surface contact with the driven arc surface, vibrations and noise during operation are suppressed, resulting in quiet operation. Furthermore, the stopper prevents the driven member from falling out of the housing space.

[0009] Another feature of the replacement brush for an electric toothbrush according to the present invention is that the plurality of driven filaments are arranged in the direction of the rotation axis, and the driven contact surface is formed in the range of the second region corresponding to the range of the first region in which at least the plurality of driven filaments are provided.

[0010] This replacement brush for electric toothbrushes allows the external forces applied to the driven member from multiple driven filaments to be efficiently received by the driven arc surface, thereby suppressing rattle of the driven member and improving its durability.

[0013] Another feature of the replacement brush for electric toothbrush according to the present invention is that at least the driven contact surface of the driven member is formed of a first synthetic resin having self-lubricating properties, and at least the driven arc surface of the brush housing is formed of a second synthetic resin that is self-lubricating and has a molecular structure different from that of the first synthetic resin.

[0014] This replacement brush for electric toothbrushes uses a self-lubricating first synthetic resin (driven member side) and a second synthetic resin (brush housing side) to keep frictional resistance low.

[0015] Other features of the replacement brush for electric toothbrushes according to the present invention are: A replacement brush for an electric toothbrush, which is attached to a toothbrush body having an electrically operated drive unit, a drive shaft rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, comprising: a driving member rotated by rotational force applied from the drive shaft, at least one driven member rotated by rotational force applied from the driving member, a brush housing having a housing space that houses the driving member and the driven member with their rotational axes parallel, and which is detachably connected to the main body housing, and a plurality of linear driven filaments provided on the driven member, wherein the brush housing has an opening that opens the housing space to the outside. The driven member has an opening and a driven arc surface centered on the rotation center of the driven member, the driven filament is implanted in the first region on the opening side of the outer circumferential surface of the driven member, the driven contact surface is formed in the second region on the outer circumferential surface of the driven member opposite to the first region and slidably contacts the driven arc surface, the driven gear portion having at least one driven tooth extending along the rotation axis is formed in the third region on the outer circumferential surface of the driven member located between the first region and the second region, and the driving gear portion having at least one driving tooth extending along the rotation axis and meshing with the driven tooth is formed on the outer circumferential surface of the driving member. The driven teeth are formed linearly and continuously along the entire length of the outer circumferential surface of the driven member in the direction of rotation, while the driving teeth are formed intermittently along the direction of rotation of the driving member.

[0016] With this replacement brush for electric toothbrushes, the intermittently formed active teeth partially contact the continuously formed driven teeth, thereby reducing frictional resistance due to contact and improving the efficiency of rotational power transmission. In addition, foreign matter that has entered between the active and driven teeth can be removed from the damaged area of ​​the active tooth.

[0017] Other features of the replacement brush for electric toothbrushes according to the present invention are: A replacement brush for an electric toothbrush, which is attached to a toothbrush body having an electrically operated drive unit, a drive shaft rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, comprising: a driving member rotated by rotational force applied from the drive shaft, at least one driven member rotated by rotational force applied from the driving member, a brush housing having a housing space that houses the driving member and the driven member with their rotational axes parallel, and which is detachably connected to the main body housing, and a plurality of linear driven filaments provided on the driven member, wherein the brush housing has an opening that opens the housing space to the outside. The driven member has an opening and a driven arc surface centered on the rotation center of the driven member, the driven filament is implanted in the first region on the opening side of the outer circumferential surface of the driven member, the driven contact surface is formed in the second region on the outer circumferential surface of the driven member opposite to the first region and slidably contacts the driven arc surface, the driven gear portion having at least one driven tooth extending along the rotation axis is formed in the third region on the outer circumferential surface of the driven member located between the first region and the second region, and the driving gear portion having at least one driving tooth extending along the rotation axis and meshing with the driven tooth is formed on the outer circumferential surface of the driving member. When one of the two driven members is designated as the first driven member, and the other of the two driven members is designated as the second driven member, and the driven gear portion of the first driven member is designated as the first driven gear portion, and the driven gear portion of the second driven member is designated as the second driven gear portion, the first driven gear portion is formed to mesh with the driving gear portion, and the second driven gear portion is formed to mesh with the first driven gear portion.

[0018] This replacement brush for electric toothbrushes allows for a shorter distance between the first and second driven members, resulting in a more compact design.

[0019] Another feature of the replacement brush for an electric toothbrush according to the present invention is that when one of the two driven members is designated as the first driven member and the other as the second driven member, and the driven gear portion of the first driven member is designated as the first driven gear portion and the driven gear portion of the second driven member is designated as the second driven gear portion, the first driven gear portion and the second driven gear portion are formed to mesh with the driving gear portion.

[0020] With this replacement brush head for electric toothbrushes, rotational force is directly applied from the driving member to the first and second driven members, allowing for precise synchronization of their movements. Therefore, the user can experience a stable and comfortable user experience.

[0021] Other features of the replacement brush for electric toothbrushes according to the present invention are: A replacement brush for an electric toothbrush, which is attached to a toothbrush body having an electrically operated drive unit, a drive shaft rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, comprising: a driving member rotated by rotational force applied from the drive shaft, at least one driven member rotated by rotational force applied from the driving member, a brush housing having a housing space that houses the driving member and the driven member with their rotation axes parallel, and which is detachably connected to the main body housing, and a plurality of linear driven filaments provided on the driven member, wherein the brush housing has an opening that opens the housing space to the outside and a driven arc surface centered on the rotation center of the driven member, and the driven filaments are implanted in a first region on the opening side of the outer circumferential surface of the driven member, A driven contact surface is formed in the second region on the outer circumferential surface of the driven member, opposite to the first region, which slidably contacts the driven arc surface; a driven gear portion is formed in the third region on the outer circumferential surface of the driven member, which is located between the first region and the second region, which has at least one driven tooth extending along the rotation axis direction; a driving gear portion is formed on the outer circumferential surface of the driving member, which has at least one driving tooth extending along the rotation axis direction and meshing with the driven tooth; when one of the two driven members is designated as the first driven member, the other as the second driven member, the driven gear portion of the first driven member is designated as the first driven gear portion, and the driven gear portion of the second driven member is designated as the second driven gear portion, the first driven gear portion and the second driven gear portion are formed to mesh with the driving gear portion. Multiple linear drive filaments provided on the drive member moreoverThe brush housing has a driving arc surface centered on the pivot point of the driving member, the driving filaments are implanted in the fourth region on the opening side of the outer circumferential surface of the driving member, a driving contact surface is formed in the fifth region on the outer circumferential surface of the driving member that is on the opposite side of the fourth region and is slidably in contact with the driving arc surface, and the driving gear portion is formed in the sixth region located between the fourth region and the fifth region on the outer circumferential surface of the driving member.

[0022] With this replacement brush for electric toothbrushes, when the active filament is pressed against the tooth, the active component can be supported by the active arc surface, which suppresses rattle of the active component and improves durability. In addition, since there is less chance of a gap forming between the active contact surface of the active component and the active arc surface of the brush housing, the overall design of the replacement brush for electric toothbrushes can be made compact.

[0023] Another feature of the replacement brush for an electric toothbrush according to the present invention is that the main member is configured to be connectable with respect to the drive shaft such that their pivot centers coincide, and when the pivot centers of the main member and the two driven members are viewed from the direction of the pivot axis, they are arranged such that the shape formed by connecting the pivot centers with straight lines is an isosceles triangle with the straight line connecting the pivot centers of the two driven members as its base.

[0024] With this replacement brush head for electric toothbrushes, the distance from the driving member to one driven member is equal to the distance from the driving member to the other driven member, improving weight balance and providing the user with a stable feel. Furthermore, compared to cases where the driving member and the two driven members are arranged in the same plane, the overall design of the replacement brush head for electric toothbrushes can be made more compact.

[0025] To achieve the above objective, the electric toothbrush according to the present invention is characterized by comprising an electric drive unit, a drive shaft that is rotated while switching the direction of rotation by the drive unit, a toothbrush body having a main body housing that accommodates these, and the above-mentioned replacement brush for the electric toothbrush.

[0026] According to this electric toothbrush, the effects obtained by the above replacement brush for an electric toothbrush can be obtained as they are.

Brief Description of the Drawings

[0027] [Figure 1] It is a diagram showing the configuration of an electric toothbrush according to an embodiment, where (A) is a plan view and (B) is a front view. [Figure 2] (A) is a perspective view showing the configuration of the drive unit, and (B) is a left side view showing the configuration of the drive unit. [Figure 3] It is a diagram showing the configuration of a replacement brush for an electric toothbrush according to the first embodiment, where (A) is a plan view, (B) is a cross-sectional view taken along line IIIB-IIIB in FIG. 1(B), and (C) is a partially enlarged plan view showing the configuration of the replacement brush for an electric toothbrush with the stopper portion removed. [Figure 4] It is an exploded front view (partial cross-section) showing the configuration of a replacement brush for an electric toothbrush according to the first embodiment. [Figure 5] It is an exploded perspective view (partial omission) showing the configuration of a replacement brush for an electric toothbrush according to the first embodiment. [Figure 6] It is a diagram showing a method of assembling a replacement brush for an electric toothbrush according to the first embodiment, where (A) is a diagram showing the step of preparing the housing body of the brush housing, (B) is a diagram showing the step of inserting the driving member into the housing body, (C) is a diagram showing the step of arranging two driven members in the accommodation space of the brush housing, and (D) is a diagram showing the step of attaching the stopper portion to the housing body. [Figure 7] It is a diagram showing the operation of an electric toothbrush according to the first embodiment, where (A) is a diagram showing the state where two driven members are rotated inward, and (B) is a diagram showing the state where two driven members are rotated outward. [Figure 8] It is an exploded perspective view (partial omission) showing the configuration of a replacement brush for an electric toothbrush according to the second embodiment. [Figure 9] (A) is a plan view showing the configuration of a replacement brush for an electric toothbrush according to the third embodiment, and (B) is a cross-sectional view corresponding to FIG. 3(B) in (A). [Figure 10] (A) is a cross-sectional view corresponding to Figure 3(B) showing the configuration of a replacement brush for an electric toothbrush according to the fourth embodiment, and (B) is a cross-sectional view corresponding to Figure 3(B) showing the configuration of a replacement brush for an electric toothbrush according to the fifth embodiment. [Modes for carrying out the invention]

[0028] Hereinafter, a replacement brush for an electric toothbrush and an electric toothbrush according to an embodiment of the present invention will be described with reference to the drawings.

[0029] (Electric toothbrush components) Figure 1(A) is a plan view showing the configuration of the electric toothbrush 10 in an embodiment, and Figure 1(B) is a front view showing the configuration of the electric toothbrush 10. Figure 2(A) is a perspective view showing the configuration of the drive unit 18, and Figure 2(B) is a left side view showing the configuration of the drive unit 18.

[0030] The electric toothbrush 10 shown in Figures 1(A) and 1(B) comprises a toothbrush body 12 and a replacement brush head (hereinafter simply referred to as "replacement brush head") 14 that is detachably attached to the toothbrush body 12. In other words, the replacement brush head 14 is a part of the electric toothbrush 10.

[0031] As shown in Figures 1(A) and 1(B), the toothbrush body 12 includes a battery 16, an electric drive unit 18 powered by electricity supplied from the battery 16, a drive shaft 20 rotated by the drive unit 18, and a body housing 22 that houses these components. The drive unit 18 is configured to reciprocate the drive shaft 20 within a predetermined angular range while switching the direction of rotation.

[0032] As shown in Figure 2(A), the drive unit 18 of this embodiment includes a motor 24, an operating plate 26 connected to the output shaft 24a of the motor 24, and an eccentric projection 28 provided on the operating plate 26. The drive unit 18 also has an elongated plate-shaped oscillating member 30 fixed to the drive shaft 20. The oscillating member 30 has an elongated hole 30a extending in the longitudinal direction, and the eccentric projection 28 is inserted into the elongated hole 30a so as to be movable in the longitudinal direction.

[0033] As shown in Figure 2(A), the base end of the drive shaft 20 is rotatably attached to a plate-shaped mounting portion 34 via a bearing portion 32. As shown in Figures 1(A) and 1(B), the tip of the drive shaft 20 protrudes outward from the main body housing 22, and a connecting portion 36 is formed at this tip, which is detachably connected to the main driving member 40 (Figure 1(B)) of the replacement brush 14.

[0034] When the line connecting the center line K1 of the operating plate 26 and the center line K2 of the drive shaft 20, as shown in Figure 2(B), is defined as a virtual line L, in the state shown in Figure 2(B) (hereinafter referred to as the "reference state"), the eccentric projection 28 is located on the virtual line L below the center line K1 of the operating plate 26. When the operating plate 26 and the eccentric projection 28 are rotated counterclockwise (or clockwise) from the reference state, the oscillating member 30 is pushed by the eccentric projection 28 and rotated counterclockwise (or clockwise) around the center line K2 of the drive shaft 20, and consequently the drive shaft 20 is rotated counterclockwise (or clockwise).

[0035] When the eccentric projection 28 reaches a virtual straight line L above the centerline K1 of the operating plate 26, the rotation of the drive shaft 20 is momentarily stopped. When the operating plate 26 and the eccentric projection 28 are further rotated counterclockwise (or clockwise), the drive shaft 20 is rotated clockwise (or counterclockwise), and the state of the drive unit 18 returns to the reference state.

[0036] The maximum rotation angle of the oscillating member 30 with respect to the virtual straight line L shown in Figure 2(B) is not particularly limited, but is preferably within the range of 3 to 15 degrees, and especially preferably within the range of 5 to 10 degrees. In this embodiment, the maximum rotation angle is set to 7 degrees. Therefore, the oscillation angle of the oscillating member 30 is set to 14 degrees.

[0037] As shown in Figures 1(A) and 1(B), the tip of the main body housing 22 has an insertion opening 38 which is inserted into the receiving opening 58 of the brush housing 50 shown in Figure 4.

[0038] (Components of replacement brush heads for electric toothbrushes) Figure 3 shows the configuration of the replacement brush 14 according to the first embodiment, where Figure 3(A) is a plan view, Figure 3(B) is a cross-sectional view along line IIIB-IIIB in Figure 1(B), and Figure 3(C) is a partially enlarged plan view showing the configuration of the replacement brush 14 with the stopper portion 54 removed. Figure 4 is an exploded front view (partial cross-section) showing the configuration of the replacement brush 14. Figure 5 is an exploded perspective view (partially omitted) showing the configuration of the replacement brush 14.

[0039] The replacement brush 14 shown in Figure 3(A) comprises a driving member 40 that is rotated by a rotational force applied from the drive shaft 20 (Figures 1(A), (B)), a first driven member 42 and a second driven member 44 that are rotated by a rotational force applied from the driving member 40, a first driven filament 46 and a second driven filament 48 that contact the user's teeth, and a brush housing 50.

[0040] As shown in Figure 4, the brush housing 50 has a housing body 52 having a housing space S that accommodates the driving member 40 and driven members 42 and 44 shown in Figures 3(A) and (B) with their pivot axes parallel, and a stopper part 54 that is detachably attached to the upper part of the housing body 52.

[0041] The housing body 52 has a housing section 56 that constitutes the housing space S, and a cylindrical connecting section 60 that is integrally formed with the housing section 56 and constitutes a receiving opening 58 into which the toothbrush body 12 insertion opening 38 (Figures 1(A), (B)) is inserted. An opening 62 is provided at the top of the housing section 56 that opens the housing space S to the outside.

[0042] As shown in Figure 5, the inner surface of the housing section 56 has a driving arc surface 64 centered on the rotation center of the driving member 40 housed in the housing space S, and a first driven arc surface 66 and a second driven arc surface 68 centered on the rotation centers of the driven members 42 and 44 housed in the housing space S. In other words, the brush housing 50 has the above-mentioned housing space S, opening 62, driving arc surface 64, first driven arc surface 66, and second driven arc surface 68.

[0043] In this embodiment, the main arc surface 64 is formed smoothly in the left-right direction at the center of the front-rear direction at the bottom of the housing section 56. The first driven arc surface 66 is formed smoothly in the left-right direction behind the main arc surface 64 at the bottom of the housing section 56, and the second driven arc surface 68 is formed smoothly in the left-right direction in front of the main arc surface 64 at the bottom of the housing section 56. In this embodiment, the main arc surface 64 and the driven arc surfaces 66,68 are formed along the entire length of the housing space S, and the lowest position of the main arc surface 64 is set lower than the lowest positions of the driven arc surfaces 66,68.

[0044] As shown in Figure 3(C), first lower recesses 70a, 70b for receiving the first detachment prevention portions 42a, 42b of the first driven member 42 and second lower recesses 72a, 72b for receiving the second detachment prevention portions 44a, 44b of the second driven member 44 are formed on the inner surfaces of both the left and right sides of the housing portion 56. The inner circumferential surfaces of the first lower recesses 70a, 70b and the second lower recesses 72a, 72b are formed in a semi-cylindrical shape that is open upward, allowing the first detachment prevention portions 42a, 42b and the second detachment prevention portions 44a, 44b to be received from the open portion.

[0045] As shown in Figure 3(C), a recess 74 is formed on the left inner surface of the housing 56 to receive the projection 40a (Figure 5) of the main drive member 40. Also, as shown in Figure 3(B), a through hole 76 is formed on the right inner surface of the housing 56 into which the main drive member 40 is inserted. Furthermore, as shown in Figure 3(C), a fitting groove 78 is formed on the upper surface of the housing 56 into which the fitting projection 84 of the stopper portion 54 shown in Figure 4 is fitted.

[0046] The stopper portion 54 shown in Figure 4 is a member for preventing the driven members 42 and 44 (Figure 3(B)) housed in the housing space S from falling out of the housing space S, and is formed in a rectangular ring shape in plan view. As shown in Figure 3(A), first upper recesses 80a and 80b that receive the first detachment prevention portions 42a and 42b (Figure 3(C)) of the first driven member 42, and second upper recesses 82a and 82b that receive the second detachment prevention portions 44a and 44b (Figure 3(C)) of the second driven member 44 are formed on the inner surfaces of both the left and right sides of the stopper portion 54. The inner circumferential surfaces of the first upper recesses 80a and 80b and the second upper recesses 82a and 82b are formed in a semi-cylindrical shape that is open downwards, and the first detachment prevention portions 42a and 42b and the second detachment prevention portions 44a and 44b can be received from the open portion.

[0047] Furthermore, as shown in Figure 4, a fitting projection 84 is formed on the lower surface of the stopper portion 54, which fits into the fitting groove 78 of the housing body 52. ​​When the stopper portion 54 is fixed to the housing body 52 by fitting the fitting projection 84 into the fitting groove 78, the first lower recesses 70a, 70b of the housing body 52 and the first upper recesses 80a, 80b of the stopper portion 54 combine to form the first circular recesses 86a, 86b shown in Figure 3(A). Also, the second lower recesses 72a, 72b of the housing body 52 and the second upper recesses 82a, 82b of the stopper portion 54 combine to form the second circular recesses 88a, 88b shown in Figure 3(A).

[0048] In this state, the inner circumferential surfaces of the first upper recesses 80a and 80b of the stopper portion 54 face the first detachment prevention portions 42a and 42b of the first driven member 42 from above (towards the opening 62), and the inner circumferential surfaces of the second upper recesses 82a and 82b of the stopper portion 54 face the second detachment prevention portions 44a and 44b of the second driven member 44 from above (towards the opening 62). The inner diameters of the first circular recesses 86a and 86b are set to be sufficiently larger than the diameters of the first detachment prevention portions 42a and 42b, and the inner diameters of the second circular recesses 88a and 88b are set to be sufficiently larger than the diameters of the second detachment prevention portions 44a and 44b. Therefore, although the driven members 42 and 44 are prevented from detaching from the housing space S, vertical movement is permitted within a certain range.

[0049] As shown in Figures 4 and 5, the main drive member 40 has a main body portion 90 arranged in the housing space S, a connecting portion 92 integrally formed with the main body portion 90 and detachably connected to the drive shaft 20 of the toothbrush body 12 (Figures 1(A), (B)), and a main drive gear portion 94 formed on the outer circumferential surface of the main body portion 90.

[0050] The main body portion 90 is formed in the shape of a round bar having a constant outer diameter along its entire length, and a projection 40a is formed at the tip of the main body portion 90 for positioning the driving member 40 within the housing space S. The length of the main body portion 90 is set to be approximately the same as the length of the housing space S in the left-right direction, and the outer diameter of the main body portion 90 is set to be sufficiently smaller than the outer diameter of the driven members 42, 44 (Figure 5).

[0051] The connecting portion 92 is formed in the shape of a round bar, with its outer diameter gradually increasing from the left end to the right end. A connecting hole 96 (Figure 4) is formed at the right end of the connecting portion 92 into which the connecting portion 36 (Figures 1(A), (B)) of the drive shaft 20 is fitted, and the left end of the connecting portion 92 is integrally connected to the main body portion 90. In other words, the main drive member 40 is configured to be connectable to the drive shaft 20 in a state where their centers of rotation coincide. The shape of the connecting portion 36 and the connecting hole 96 is not particularly limited, but it is desirable that they be non-circular, such as D-shaped or polygonal, in order to prevent slippage and reliably transmit rotational force.

[0052] The driving gear portion 94 is the portion that meshes with the first driven gear portion 114 of the first driven member 42. As shown in Figure 5, the driving gear portion 94 has at least one (one in this embodiment) driving tooth 94a formed on the outer circumferential surface of the main body portion 90 so as to extend along the rotation axis direction. The driving tooth 94a in this embodiment is formed intermittently along the rotation axis direction of the driving member 40 so as to be distributed along the entire length of the main body portion 90, i.e., the entire length of the outer circumferential surface of the driving member 40 in the rotation axis direction. In other words, the driving tooth 94a in this embodiment is divided by a plurality (three in this embodiment) of missing portions 100. Furthermore, a region is secured on the outer circumferential surface of the main body portion 90 in which the driving gear portion 94 is not formed, and the cylindrical outer surface of this region is a driving contact surface 102 that slidably contacts the driving arc surface 64 of the brush housing 50.

[0053] As shown in Figure 5, the first driven member 42 is a rod-shaped member placed in the housing space S, and has a solid rod-shaped first main body portion 104 and protruding first detachment prevention portions 42a and 42b formed at both axial ends of the first main body portion 104.

[0054] A flat first flocked surface 108 is formed in the first region 106a on the opening 62 side of the outer circumferential surface of the first driven member 42 (first main body portion 104). Multiple (six in this embodiment) first flocked holes 110 are formed on the first flocked surface 108, arranged in the direction of the rotation axis, and into which the first driven filaments 46 are flocked. In other words, multiple first driven filaments 46 are provided on the first flocked surface 108, arranged in the direction of the rotation axis.

[0055] In the second region 106b, located on the outer circumferential surface of the first driven member 42 (first main body portion 104) opposite to the first region 106a, an arc-shaped first driven contact surface 112 is formed with the same curvature as the first driven arc surface 66, and is slidably in contact with the first driven arc surface 66. The first driven contact surface 112 is formed in a range of the second region 106b that corresponds to at least the range of the first region 106a where the plurality of first driven filaments 46 are provided.

[0056] A first driven gear portion 114 is formed in a third region 106c located between the first region 106a and the second region 106b on the outer circumferential surface of the first driven member 42 (first main body portion 104). The first driven gear portion 114 is the portion that meshes with the main gear portion 94 of the main member 40 and the second driven gear portion 126 of the second driven member 44, and has at least one (five in this embodiment) first driven teeth 114a that extend linearly and continuously along the rotation axis direction. In this embodiment, the first driven teeth 114a are formed linearly and continuously along the entire length in the rotation axis direction on the outer circumferential surface of the first driven member 42. In this embodiment, the two first driven teeth 114a located at both ends in the circumferential direction are formed in a shape in which a portion is missing compared to the other three first driven teeth 114a.

[0057] As shown in Figure 5, the second driven member 44 is a rod-shaped member positioned in the housing space S, and, like the first driven member 42, has a solid rod-shaped second main body portion 116 and protruding second detachment prevention portions 44a and 44b formed at both axial ends of the second main body portion 116.

[0058] A flat second flocked surface 120 is formed in the first region 118a on the opening 62 side of the outer circumferential surface of the second driven member 44 (second main body portion 116). Multiple (six in this embodiment) second flocked holes 122 are formed on the second flocked surface 120, arranged in the direction of the rotation axis, into which the second driven filaments 48 are flocked. In other words, multiple second driven filaments 48 are provided on the second flocked surface 120, arranged in the direction of the rotation axis.

[0059] In the second region 118b, located on the outer circumferential surface of the second driven member 44 (second main body portion 116) opposite to the first region 118a, an arc-shaped second driven contact surface 124 is formed with the same curvature as the second driven arc surface 68, and is slidably in contact with the second driven arc surface 68. The second driven contact surface 124 is formed in a region of the second region 118b that corresponds to at least the area of ​​the first region 118a where the plurality of second driven filaments 48 are provided.

[0060] A second driven gear portion 126 is formed in a third region 118c located between the first region 118a and the second region 118b on the outer circumferential surface of the second driven member 44 (second main body portion 116). The second driven gear portion 126 is the portion that meshes with the first driven gear portion 114 of the first driven member 42, and has at least one (five in this embodiment) second driven teeth 126a that extend linearly and continuously along the rotation axis direction. In this embodiment, the second driven teeth 126a are formed linearly and continuously along the entire length in the rotation axis direction on the outer circumferential surface of the second driven member 44. In this embodiment, the two second driven teeth 126a located at both ends in the circumferential direction are formed in a shape in which a portion is missing compared to the other three second driven teeth 126a.

[0061] As shown in Figure 5, in this embodiment, spur gears having a tooth profile based on an involute curve are used as the driving gear portion 94, the first driven gear portion 114, and the second driven gear portion 126. However, the shapes of the driving teeth 94a and the driven teeth 114a, 126a can be changed as appropriate. For example, they may be formed in a plate shape that extends along the rotation axis direction and has two parallel sides. Also, in this embodiment, the driving teeth 94a are formed intermittently along the rotation axis direction of the driving member 40, but the driving teeth 94a may be formed linearly and continuously along the rotation axis direction. Furthermore, the types of driving gear portions 94 and driven gear portions 114, 126 can be changed as appropriate. For example, helical gears may be used.

[0062] As shown in Figure 3(B), when the rotation centers of the main member 40 and the two driven members 42 and 44 are viewed from the direction of the rotation axis, the shape formed by connecting each rotation center with lines P1, P2, and P3 is an isosceles triangle with line P1, which connects the rotation centers of the two driven members 42 and 44, as its base. In other words, the main member 40 and the two driven members 42 and 44 are arranged such that the shape formed by connecting each rotation center with lines P1, P2, and P3 is an isosceles triangle with line P1, which connects the rotation centers of the two driven members 42 and 44, as its base.

[0063] In this embodiment, at least the driven contact surfaces 112 and 124 of the driven members 42 and 44 shown in Figure 5 are formed of a first synthetic resin having self-lubricating properties, and at least the driven arc surfaces 66 and 68 and the driving arc surface 64 of the brush housing 50 are formed of a second synthetic resin that has self-lubricating properties and a molecular structure different from that of the first synthetic resin. At least the driving contact surface 102 of the driving member 40 is formed of a third synthetic resin that has self-lubricating properties and a molecular structure different from that of the second synthetic resin.

[0064] The types of the first, second, and third synthetic resins are not particularly limited as long as they are self-lubricating, but in this embodiment, glass fiber reinforced polyphenylene sulfide (PPS) is used as the first synthetic resin that forms the driven members 42 and 44. In addition, unreinforced polybutylene terephthalate (PBT) is used as the second synthetic resin that forms the brush housing 50, and a synthetic resin that uses polyoxymethylene (POM) as a base material and contains polytetrafluoroethylene (PTFE) is used as the third synthetic resin that forms the driving member 40.

[0065] The first driven filament 46 and the second driven filament 48 shown in Figure 3(B) are components that have the function of brushing the user's teeth and are formed in a continuous linear shape from a synthetic resin such as nylon or polypropylene. The length of the driven filaments 46 and 48 is not particularly limited, but it is desirable to be in the range of 7 mm to 15 mm. In particular, it is desirable to be in the range of 9 mm to 12 mm, and in this embodiment, it is set to 10 mm. As shown in Figure 5, a plurality of first driven filaments 46 are bundled together in a cylindrical shape and implanted in the first filament holes 110 of the first driven member 42. Similarly, a plurality of second driven filaments 48 are bundled together in a cylindrical shape and implanted in the second filament holes 122 of the second driven member 44. Note that in Figure 5, the driven filaments 46 and 48 are shown as dashed lines (dotted lines).

[0066] As shown in Figure 3(B), the driven filaments 46 and 48 implanted on the first driven member 42 and the second driven member 44 have their cylindrical bundles' centerlines (not shown) positioned outward from the rotational axis of each driven member 42 and 44. This results in an asymmetrical trajectory for the swinging of the driven filaments 46 and 48, producing a "sweeping effect" similar to manual brushing, allowing for efficient tooth cleaning.

[0067] The eccentricity distance from the pivot axis to the centerlines of the driven filaments 46 and 48 is not particularly limited, but in this embodiment, it is set within the range of 0.3 mm or more and 0.6 mm or less. If the eccentricity distance is less than 0.3 mm, the asymmetry of the trajectory is insufficient, making it difficult to obtain a sufficient "sweeping effect" like that of hand polishing. On the other hand, if it exceeds 0.6 mm, the centrifugal force balance during rotation is disrupted, making it easier for vibrations and rattles to occur.

[0068] (How to assemble a replacement brush head for an electric toothbrush) Figure 6 shows the assembly method of the replacement brush 14 according to the first embodiment. Figure 6(A) shows the process of preparing the housing body 52 of the brush housing 50, Figure 6(B) shows the process of inserting the driving member 40 into the housing body 52, Figure 6(C) shows the process of arranging the two driven members 42 and 44 in the housing space S of the brush housing 50, and Figure 6(D) shows the process of attaching the stopper part 54 to the housing body 52.

[0069] When assembling the replacement brush 14, first prepare the housing body 52 with the stopper portion 54 removed, as shown in Figure 6(A). Next, as shown in Figure 6(B), insert the main drive member 40 through the through hole 76 of the housing body 52, bringing the main drive contact surface 102 into contact with the main drive arc surface 64, and position the projection 40a shown in Figure 5 inside the recess 74 shown in Figure 3(C).

[0070] Next, as shown in Figure 6(C), two driven members 42 and 44 are placed in the housing space S of the brush housing 50. Specifically, the first detachment prevention parts 42a and 42b of the first driven member 42 and the second detachment prevention parts 44a and 44b of the second driven member 44 are placed from above in relation to the first lower recesses 70a and 70b and the second lower recesses 72a and 72b shown in Figure 3(C). Finally, as shown in Figure 6(D), the stopper part 54 is attached to the upper part of the housing body 52. ​​Specifically, the fitting projection 84 of the stopper part 54 is fitted into the fitting groove 78 of the housing body 52 shown in Figure 3(C).

[0071] (Electric toothbrush operation) Figure 7 shows the operation of the electric toothbrush 10 according to the first embodiment. Figure 7(A) shows the state in which the two driven members 42 and 44 are rotated inward, and Figure 7(B) shows the state in which the two driven members 42 and 44 are rotated outward. The arrows in the figures indicate the direction in which the driven filaments 46 and 48 rotate.

[0072] When the electric toothbrush 10 shown in Figures 1(A) and 1(B) is switched on, and the motor 24 of the drive unit 18 shown in Figure 2(A) is driven, the drive shaft 20 rotates while switching its rotational direction, and this rotational force is transmitted to the main member 40 shown in Figures 7(A) and 7(B). As a result, the main member 40 rotates stably while switching its rotational direction with its main contact surface 102 in surface contact with the main arc surface 64, and the driven members 42 and 44 rotate stably while switching their rotational direction with their driven contact surfaces 112 and 124 in surface contact with the driven arc surfaces 66 and 68. As a result, the driven filaments 46 and 48 oscillate within a certain angular range.

[0073] (Effects of the electric toothbrush according to the first embodiment) According to the electric toothbrush 10 of this embodiment, the above configuration can achieve the following effects. Specifically, when the driven filaments 46 and 48 are pressed against the teeth, the load (external force) applied to the driven members 42 and 44 can be distributed and received by the driven arc surfaces 66 and 68, thereby suppressing rattling of the driven members 42 and 44 and improving durability.

[0074] Since gaps are unlikely to occur between the main contact surface 102 of the main member 40 and the main arc surface 64 of the brush housing 50, and gaps are unlikely to occur between the driven contact surfaces 112 and 124 of the driven members 42 and 44 and the driven arc surfaces 66 and 68 of the brush housing 50, the entire replacement brush 14 can be made compact. Furthermore, since the driven gear sections 114 and 126 are integrally formed with the driven members 42 and 44, and the main gear section 94 is integrally formed with the main member 40, there is no need to prepare these gear sections as separate parts, which reduces manufacturing costs and the number of assembly steps.

[0075] Since the driven contact surfaces 112 and 124 smoothly slide while making surface contact with the driven arc surfaces 66 and 68, vibrations and noise during operation are suppressed, resulting in quiet operation.

[0076] Multiple driven filaments 46, 48 are arranged in the direction of the rotation axis, and the driven contact surfaces 112, 124 are formed in the range of the second region 106b, 118b, which corresponds to the range of the first region 106a, 118a where at least multiple driven filaments 46, 48 are provided. As a result, the load (external force) applied to the driven members 42, 44 can be efficiently received by the driven arc surfaces 66, 68. This suppresses rattling of the driven members 42, 44 and improves durability.

[0077] First detachment prevention portions 42a and 42b are provided at both ends of the first driven member 42 in the direction of the rotation axis, and second detachment prevention portions 44a and 44b are provided at both ends of the second driven member 44 in the direction of the rotation axis. The brush housing 50 has stopper portions 54 that face these detachment prevention portions from the opening 62 side, so that the driven members 42 and 44 can be prevented from falling out of the housing space S.

[0078] Since at least the driven contact surfaces 112 and 124 of the driven members 42 and 44 are formed of a first resin that has self-lubricating properties, and at least the driven arc surfaces 66 and 68 of the brush housing 50 are formed of a second resin that has self-lubricating properties and a different molecular structure from the first resin, the frictional resistance between the driven members 42 and 44 and the driven contact surfaces 112 and 124 can be kept low.

[0079] Since the driven teeth 114a are formed linearly and continuously along the entire length of the driven member 42 in the direction of the rotation axis, and the driving teeth 94a are formed intermittently along the direction of the rotation axis of the driving member 40, frictional resistance due to contact between the two can be reduced, and the efficiency of rotational power transmission can be improved. In addition, foreign matter that gets stuck between the driving teeth 94a and the driven teeth 114a can be removed from the missing portion 100 of the driving teeth 94a.

[0080] The first driven gear section 114 is formed to mesh with the driving gear section 94, and the second driven gear section 126 is formed to mesh with the first driven gear section 114. This allows the distance between the first driven member 42 and the second driven member 44 to be shortened, making the entire replacement brush 14 more compact.

[0081] When the rotation centers of the main member 40 and the two driven members 42 and 44 are viewed from the direction of the rotation axis, the shape formed by connecting each rotation center with straight lines P1, P2, and P3 is an isosceles triangle with the straight line P1 connecting the rotation centers of the two driven members 42 and 44 as its base. In other words, the distance from the main member 40 to the first driven member 42 is equal to the distance from the main member 40 to the second driven member 44. Therefore, the weight balance is improved, and the user can obtain a stable feeling of use. In addition, the overall structure of the replacement brush 14 can be made more compact compared to the case where the main member 40 and the two driven members 42 and 44 are arranged in the same plane.

[0082] (modified version) In implementing the present invention, the invention is not limited to the embodiments described above, and various modifications are possible as long as they do not depart from the objective of the invention. That is, in the embodiments described above, the brush housing 50, the driving member 40, the first driven member 42, and the second driven member 44 are all made of synthetic resin, but in these cases, only the sliding parts where the members come into contact and slide against each other may be made of ceramic or metal material, and the other parts may be made of synthetic resin.

[0083] In the above embodiment, the brush housing 50 is configured to be separable into a housing body 52 and a stopper portion 54, but the number of divisions of the brush housing 50 may be three or more. In addition, instead of fitting, adhesive, welding, or screw joining may be used as the method for joining the divided parts. Furthermore, the brush housing 50 may be configured as a single component, in which case the inner circumference of the opening 62 may be configured to expand elastically so that the two driven members 42 and 44 can be inserted into and removed from the housing space S.

[0084] In the above embodiment, the rotational force of the drive shaft 20 constituting the toothbrush body 12 is directly applied to the main drive member 40 of the replacement brush 14. However, the rotational force of the drive shaft 20 may be applied indirectly to the main drive member 40 via a power transmission mechanism such as a gear unit. In this case, the power transmission mechanism may be incorporated into either the main body housing 22 or the brush housing 50.

[0085] Figure 8 is an exploded perspective view (partially omitted) showing the configuration of the replacement brush 128 according to the second embodiment. Figure 9(A) is a plan view showing the configuration of the replacement brush 130 according to the third embodiment, and Figure 9(B) is a cross-sectional view corresponding to Figure 3(B) in Figure 9(A). Figure 10(A) is a cross-sectional view corresponding to Figure 3(B) showing the configuration of the replacement brush 132 according to the fourth embodiment, and Figure 10(B) is a cross-sectional view corresponding to Figure 3(B) showing the configuration of the replacement brush 134 according to the fifth embodiment.

[0086] As shown in Figure 5, in the above embodiment, the active arc surface 64 and the driven arc surfaces 66, 68 are each formed as a single smooth arc surface, and the active contact surface 102 and the driven contact surfaces 112, 124 are each formed as a single smooth arc surface. However, multiple fine grooves or recesses (not shown) may be formed on these surfaces, or multiple linear protrusions or multiple point-shaped protrusions extending in the circumferential direction may be formed. With these configurations, the area of ​​the sliding portion can be reduced, so frictional resistance can be kept low.

[0087] In the replacement brush 128 according to the second embodiment shown in Figure 8, multiple (five in the second embodiment) linear projections 136a, 136b extending in the circumferential direction are formed at intervals in the rotation axis direction in the second regions 106b, 118b of the driven members 42, 44, and the surfaces of each projection 136a, 136b become driven contact surfaces 112, 124. Therefore, the contact area of ​​the driven contact surfaces 112, 124 with respect to the driven arc surfaces 66, 68, i.e., the area of ​​the sliding portion, can be reduced, and frictional resistance can be kept low.

[0088] As shown in Figures 3(A) and 3(B), in the above embodiment, rotational force is transmitted from the driving member 40, which does not have a filament, to the two driven members 42 and 44. However, it is also possible to configure the system so that rotational force is transmitted from the driving member, which has a filament, to at least one driven member.

[0089] The replacement brush 130 according to the third embodiment shown in Figures 9(A) and (B) comprises a driving member 138, a driving filament 140 provided on the driving member 138, a driven member 142, and a driven filament 144 provided on the driven member 142. A bristle surface 148 is formed in the fourth region 146a on the opening 62 side of the outer circumferential surface of the driving member 138, on which the driving filament 140 is implanted. A driving contact surface 154 is formed in the fifth region 146b on the outer circumferential surface of the driving member 138, on the opposite side from the fourth region 146a, on which the driving contact surface 154 contacts the driving arc surface 152 of the brush housing 150. A driving gear portion 156 is formed in the sixth region 146c, which is located between the fourth region 146a and the fifth region 146b.

[0090] Furthermore, the main drive member 138 has an integrally formed connecting portion 158 that is detachably connected to the drive shaft 20 (Figure 2(A)) of the toothbrush body 12, and the brush housing 150 is configured to be separable in the vertical direction (or front-to-back direction) in order to accommodate the connecting portion 158 in its internal space.

[0091] With this replacement brush 130, when the active filament 140 is pressed against the tooth, the active member 138 can be supported by the active arc surface 152, thereby suppressing rattle of the active member 138 and improving durability. In addition, since a gap is less likely to occur between the active contact surface 154 of the active member 138 and the active arc surface 152 of the brush housing 150, the entire replacement brush 130 can be made compact.

[0092] The replacement brush 132 according to the fourth embodiment shown in Figure 10(A) comprises a driving member 160, a driving filament 162 provided on the driving member 160, a first driven member 164, a first driven filament 166 provided on the first driven member 164, a second driven member 168, and a second driven filament 170 provided on the second driven member 168. A driving gear portion 172 is formed on the driving member 160, a first driven gear portion 174 is formed on the first driven member 164, and a second driven gear portion 176 is formed on the second driven member 168.

[0093] The driving member 160 is positioned between the two driven members 164 and 168, and the pivot axes of the driving member 160 and the driven members 164 and 168 are located in the same plane. Furthermore, the distance from the pivot axis of the driving member 160 to the pivot axes of the driven members 164 and 168 are set to be equal in order to improve weight balance.

[0094] The driven gear portions 174 and 176 of the driven members 164 and 168 are formed to mesh with the drive gear portion 172 of the drive member 160, thereby enabling the simultaneous transmission of rotational force from the drive member 160 to the two driven members 164 and 168. Consequently, the operation of the two driven members 164 and 168 can be precisely synchronized, providing the user with a stable and reliable user experience.

[0095] As shown in Figure 3(B), in the above embodiment, driven filaments 46 and 48 are provided on each of the two driven members 42 and 44. However, as in the replacement brush 134 of the fifth embodiment shown in Figure 10(B), at least one driven member 178 may be provided with a rod-shaped massage member 180 made of a soft material for massaging the gums, instead of driven filaments. [Explanation of Symbols]

[0096] K1, K2…Centerline, L…Virtual straight line, S…Accommodation space, P1, P2, P3…Straight line, 10…Electric toothbrush, 12…Toothbrush body, 14…Replacement brush for electric toothbrush, 16…Battery, 18…Drive unit, 20…Drive shaft, 22…Main body housing, 24…Motor, 24a…Output shaft, 26…Operating plate, 28…Eccentric projection, 30…Oscillating member, 30a…Slot, 32…Bearing part, 34…Mounting part, 36…Connecting part, 38…Insertion port, 40…Main driving member, 40a…Protrusion , 42...First driven member, 42a...First detachment prevention part, 42b...First detachment prevention part, 44...Second driven member, 44a...Second detachment prevention part, 44b...Second detachment prevention part, 46...First driven filament, 48...Second driven filament, 50...Brush housing, 52...Housing body, 54...Stopper part, 56...Housing part, 58...Receiving opening, 60...Connecting part, 62...Opening, 64...Driven arc surface, 66...First driven arc surface, 68...Second driven arc surface, 70a,70b... First lower recess, 72a, 72b... Second lower recess, 74... Recess, 76... Through hole, 78... Fitting groove, 80a, 80b... First upper recess, 82a, 82b... Second upper recess, 84... Fitting projection, 86a, 86b... First circular recess, 88a, 88b... Second circular recess, 90... Main body, 92... Connecting part, 94... Driving gear part, 94a... Driving tooth, 96... Connecting hole, 100... Missing part, 102... Driving contact surface, 104... First main body, 106a... First region, 106b... Second region ,106c...Third area, 108...First bristle surface, 110...First bristle hole, 112...First driven contact surface, 114...First driven gear part, 114a...First driven tooth, 116...Second main body part, 118a...First area, 118b...Second area, 118c...Third area, 120...Second bristle surface, 122...Second bristle hole, 124...Second driven contact surface, 126...Second driven gear part, 126a...Second driven tooth, 128,130,132,134...Replacement brush for electric toothbrush, 136a,136b…Protrusion, 138…Driver member, 140…Driver filament, 142…Driven member, 144…Driven filament, 146a…Fourth region, 146b…Fifth region, 146c…Sixth region, 148…Brush surface, 150…Brush housing, 152…Driver arc surface, 154…Driver contact surface, 156…Driver gear section, 158…Connecting section, 160…Driver member, 162…Driver filament, 164…First driven member, 166…First driven filament, 168…Second driven member, 170…Second driven filament, 172…Driver gear section, 174…First driven gear section, 176…Second driven gear section, 178…Driven member, 180…Massage member.

Claims

1. A replacement brush for an electric toothbrush, which is attached to a toothbrush body having an electrically operated drive unit, a drive shaft that is rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, A driving member that is rotated by the rotational force applied from the drive shaft, At least one driven member that is rotated by the rotational force applied from the driving member, A brush housing having a housing space for accommodating the driving member and the driven member with their pivot axes parallel to each other, and which is detachably connected to the main body housing, The driven member comprises a plurality of linear driven filaments, The brush housing has an opening that opens the housing space to the outside and a driven arc surface centered on the rotation center of the driven member, The first region on the opening side of the outer circumferential surface of the driven member is flocked with the driven filament. A driven contact surface is formed in the second region on the outer circumferential surface of the driven member, which is located on the opposite side of the first region, and which slidably contacts the driven arc surface. A third region located between the first region and the second region on the outer circumferential surface of the driven member is formed, and a driven gear portion having at least one driven tooth extending along the rotation axis direction is formed therein. A drive gear portion is formed on the outer circumferential surface of the drive member, having at least one drive tooth that extends along the rotation axis and meshes with the driven tooth. The driven member is provided with protruding detachment prevention parts at both ends in the direction of the rotation axis, The brush housing has a stopper portion facing the detachment prevention portion from the opening side, and is a replacement brush for an electric toothbrush.

2. Multiple of the driven filaments are arranged in the direction of the rotation axis, The replacement brush for an electric toothbrush according to claim 1, wherein the driven contact surface is formed in the range of the second region corresponding to the range of the first region in which at least a plurality of the driven filaments are provided.

3. At least the driven contact surface of the driven member is formed of a first synthetic resin having self-lubricating properties. The replacement brush for an electric toothbrush according to claim 1, wherein at least the driven arc surface of the brush housing is formed of a second synthetic resin that is self-lubricating and has a molecular structure different from that of the first synthetic resin.

4. A replacement brush for an electric toothbrush, which is attached to a toothbrush body having an electric drive unit, a drive shaft that is rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, A driving member that is rotated by the rotational force applied from the drive shaft, At least one driven member that is rotated by the rotational force applied from the driving member, A brush housing having a housing space for accommodating the driving member and the driven member with their pivot axes parallel to each other, and which is detachably connected to the main body housing, The driven member comprises a plurality of linear driven filaments, The brush housing has an opening that opens the housing space to the outside and a driven arc surface centered on the rotation center of the driven member, The first region on the opening side of the outer circumferential surface of the driven member is flocked with the driven filament. A driven contact surface is formed in the second region on the outer circumferential surface of the driven member, which is located on the opposite side of the first region, and which slidably contacts the driven arc surface. A third region located between the first region and the second region on the outer circumferential surface of the driven member is formed, and a driven gear portion having at least one driven tooth extending along the rotation axis direction is formed therein. A drive gear portion is formed on the outer circumferential surface of the drive member, having at least one drive tooth that extends along the rotation axis and meshes with the driven tooth. The driven teeth are formed linearly and continuously along the entire length of the outer circumferential surface of the driven member in the direction of the rotation axis, The aforementioned driving teeth are formed intermittently along the rotation axis of the driving member, and are replacement brushes for an electric toothbrush.

5. A replacement brush for an electric toothbrush, which is attached to a toothbrush body having an electric drive unit, a drive shaft that is rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, A driving member that is rotated by the rotational force applied from the drive shaft, At least one driven member that is rotated by the rotational force applied from the driving member, A brush housing having a housing space for accommodating the driving member and the driven member with their pivot axes parallel to each other, and which is detachably connected to the main body housing, The driven member comprises a plurality of linear driven filaments, The brush housing has an opening that opens the housing space to the outside and a driven arc surface centered on the rotation center of the driven member, The first region on the opening side of the outer circumferential surface of the driven member is flocked with the driven filament. A driven contact surface is formed in the second region on the outer circumferential surface of the driven member, which is located on the opposite side of the first region, and which slidably contacts the driven arc surface. A third region located between the first region and the second region on the outer circumferential surface of the driven member is formed, and a driven gear portion having at least one driven tooth extending along the rotation axis direction is formed therein. A drive gear portion is formed on the outer circumferential surface of the drive member, having at least one drive tooth that extends along the rotation axis and meshes with the driven tooth. One of the two driven members is designated as the first driven member. The other of the two driven members is designated as the second driven member. The driven gear portion of the first driven member is defined as the first driven gear portion. When the driven gear portion of the second driven member is designated as the second driven gear portion, The first driven gear portion is formed to mesh with the driving gear portion, The second driven gear portion is formed to mesh with the first driven gear portion, and is a replacement brush for an electric toothbrush.

6. One of the two driven members is designated as the first driven member. The other of the two driven members is designated as the second driven member. The driven gear portion of the first driven member is defined as the first driven gear portion. When the driven gear portion of the second driven member is designated as the second driven gear portion, The replacement brush for an electric toothbrush according to claim 1, wherein the first driven gear portion and the second driven gear portion are formed to mesh with the driving gear portion.

7. A replacement brush for an electric toothbrush, which is attached to a toothbrush body having an electric drive unit, a drive shaft that is rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, A driving member that is rotated by the rotational force applied from the drive shaft, At least one driven member that is rotated by the rotational force applied from the driving member, A brush housing having a housing space for accommodating the driving member and the driven member with their pivot axes parallel to each other, and which is detachably connected to the main body housing, The driven member comprises a plurality of linear driven filaments, The brush housing has an opening that opens the housing space to the outside and a driven arc surface centered on the rotation center of the driven member, The first region on the opening side of the outer circumferential surface of the driven member is flocked with the driven filament. A driven contact surface is formed in the second region on the outer circumferential surface of the driven member, which is located on the opposite side of the first region, and which slidably contacts the driven arc surface. A third region located between the first region and the second region on the outer circumferential surface of the driven member is formed, and a driven gear portion having at least one driven tooth extending along the rotation axis direction is formed therein. A drive gear portion is formed on the outer circumferential surface of the drive member, having at least one drive tooth that extends along the rotation axis and meshes with the driven tooth. One of the two driven members is designated as the first driven member. The other of the two driven members is designated as the second driven member. The driven gear portion of the first driven member is defined as the first driven gear portion. When the driven gear portion of the second driven member is designated as the second driven gear portion, The first driven gear portion and the second driven gear portion are formed to mesh with the driving gear portion, The main drive member further comprises a plurality of linear main drive filaments, The brush housing has a main arc surface centered on the pivot point of the main member, The fourth region on the opening side of the outer circumferential surface of the main drive member is flocked with the main drive filaments. A fifth region located on the outer circumferential surface of the main drive member, opposite to the fourth region, is formed with a main contact surface that slidably contacts the main arc surface. The drive gear portion is formed in a sixth region located between the fourth region and the fifth region on the outer circumferential surface of the drive member, and is a replacement brush for an electric toothbrush.

8. The main drive member is configured to be connectable to the drive shaft in a state where their pivot centers coincide. The replacement brush for an electric toothbrush according to any one of claims 5 to 7, wherein when the rotation centers of the main member and the two driven members are viewed from the direction of the rotation axis, they are arranged such that the shape formed by connecting the rotation centers of each member with a straight line is an isosceles triangle with the straight line connecting the rotation centers of the two driven members as its base.

9. A toothbrush body having an electrically operated drive unit, a drive shaft that is rotated by the drive unit while switching the direction of rotation, and a main body housing that houses these, An electric toothbrush comprising a replacement brush for an electric toothbrush according to any one of claims 1 to 7.

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