An electric toothbrush head

Abstract

This invention discloses an electric toothbrush head, including a brush handle and a brush disc. The brush handle has a cavity in the middle, and the brush disc is fitted with bristles. The brush disc is connected to the upper end of the brush handle and can rotate relative to the brush handle. A transmission rod is installed inside the cavity of the brush handle. One end of an L-shaped linkage rod is connected to the brush disc, and the other end of the L-shaped linkage rod is connected to the upper part of the transmission rod. The other end of the L-shaped linkage rod does not coincide with the rotation center axis of the transmission rod. When the electric toothbrush head is installed on an electric toothbrush drive body, the lower part of the transmission rod is connected to the drive shaft of the electric toothbrush drive body. The transmission rod is driven to rotate back and forth circumferentially through the drive shaft, and the transmission rod then drives the brush disc to rotate back and forth through the L-shaped linkage rod. Preferably, the brush handle includes a head, a middle support part, and a locking part; the transmission rod is pivotally connected in the middle support part, and the axial direction of the transmission rod is limited by the middle support part and the locking part. The transmission component of this invention has a simple structure, is easy to assemble, and has high transmission reliability.

Description

Technical Field

[0001] This invention relates to the field of electric toothbrush manufacturing technology, and in particular to an electric toothbrush head. Background Technology

[0002] Electric toothbrushes work by rapidly rotating or vibrating a motor, causing the brush head to rotate or vibrate at high frequency. This instantly breaks down toothpaste into fine foam, deeply cleaning between teeth. Simultaneously, the bristle vibrations promote blood circulation in the mouth and massage the gums. Therefore, electric toothbrushes have gradually gained acceptance and use among the public. Current electric toothbrushes typically consist of a motor and a brush head. The brush head is assembled onto the motor and needs to be replaced when the bristles wear down. Figure 1 This is an existing electric toothbrush drive body, whose drive shaft 10 rotates back and forth in the circumferential direction. The power for the circumferential rotation of the drive shaft 10 can be achieved by setting a swing motor or other structures on the electric toothbrush drive body 100. The drive shaft 10 may also be provided with a locking groove 101 to facilitate connection with the electric toothbrush head.

[0003] In order to enable the electric toothbrush head to cooperate with the aforementioned electric toothbrush drive body, so that the brush plate and bristles can swing back and forth together, various electric toothbrush head structures have been designed. For example, a Chinese invention patent with patent number ZL201220407088.5 and title "Electric Toothbrush Head" was published on February 13, 2013. It includes a brush handle and a brush disc with bristles installed at the top of the brush handle. The brush disc is installed on the mounting end at the top of the brush handle by a metal positioning pin and can swing within a swing angle of 20-35 degrees. The brush handle is provided with a transmission component, which includes a mounting rod made of plastic material. The mounting rod is provided with a transmission shaft. The transmission shaft is fitted with a spring and installed in the mounting hole of the mounting rod. The top of the transmission shaft is provided with a swing pin that can swing the brush disc left and right. The top of the mounting rod is also provided with a fixing pin. After the fixing pin is installed in the brush handle, the mounting rod can rotate left and right around the fixing pin as the axis. The tail of the mounting rod is provided with a mounting hole for installing a drive component. Under the drive of the drive device, the transmission component drives the brush disc to swing left and right. The transmission components of this type of electric toothbrush head include a mounting rod, a drive shaft, a spring, a swing pin, and a fixing pin. The structure is relatively complex and assembly is difficult, and the reliability of the transmission needs to be improved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an electric toothbrush head with a simple transmission component structure, which is easy to assemble and has high transmission reliability.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: an electric toothbrush head includes a brush rod and a brush disc. The brush rod has a cavity in the middle, and the brush disc is equipped with bristles. The brush disc is connected to the upper end of the brush rod and can rotate relative to the brush rod. A transmission rod is installed in the cavity of the brush rod. One end of an L-shaped linkage rod is connected to the brush disc, and the other end of the L-shaped linkage rod is connected to the upper part of the transmission rod. The other end of the L-shaped linkage rod does not coincide with the rotation center axis of the transmission rod. When the electric toothbrush head is installed on the electric toothbrush drive body, the lower part of the transmission rod is connected to the drive shaft of the electric toothbrush drive body. The transmission rod is driven to rotate back and forth in the circumferential direction through the drive shaft, and the transmission rod then drives the brush disc to rotate back and forth through the L-shaped linkage rod.

[0006] Further improvements include a first connecting hole on the upper part of the transmission rod, the central axis of which is parallel to but does not coincide with the rotational central axis of the transmission rod; a second connecting hole on the brush disc, the central axis of which is parallel to but does not coincide with the rotational central axis of the brush disc; one end of the L-shaped linkage rod is inserted into the second connecting hole, and the other end is inserted into the first connecting hole. This facilitates installation.

[0007] Preferably, the brush rod includes a head, a middle support, and a locking part. The lower end of the head is sleeved with the upper end of the middle support, and the locking part is locked with the middle support. The transmission rod is pivotally connected inside the middle support, and the axial direction of the transmission rod is limited by the middle support and the locking part. This facilitates the manufacturing and installation of the brush rod.

[0008] As an improvement, the head is provided with multiple elastic snap-fit ​​protrusions, the free ends of which are provided with hooks. The inner surfaces of the multiple snap-fit ​​protrusions are on the same cylindrical surface. A pivot shaft extends outward from the side of the brush disc away from the bristles. An annular positioning groove is provided in the middle of the pivot shaft. The outer circumferential surface of the pivot shaft mates with the inner surfaces of the multiple snap-fit ​​protrusions. The hooks on each snap-fit ​​protrusion engage with the annular positioning groove.

[0009] Furthermore, the lower end of the transmission rod is provided with a connecting recess, the inner side of the connecting recess is provided with a snap-fit ​​protrusion, the snap-fit ​​part is provided with a protrusion that fits into the connecting recess, the snap-fit ​​part is also provided with a through hole corresponding to the connecting recess, and the outer circumferential surface of the drive shaft is provided with a snap-fit ​​groove. When the drive shaft passes through the through hole and is inserted into the connecting recess, the snap-fit ​​protrusion cooperates with the snap-fit ​​groove.

[0010] The transmission rod has a limiting shoulder on its outer circumference in the middle, and a limiting part inside the middle support part, which cooperates with the limiting shoulder. This structure facilitates the assembly and axial positioning of the transmission rod.

[0011] As another improvement, a rotating seat is pivotally connected to the upper part of the brush rod, and a connecting shaft extends outward from the rear of the brush disk. The connecting shaft is connected to the rotating seat in an axially movable and circumferentially fixed manner. One end of the L-shaped linkage rod is connected to the brush disk through the connecting rotating seat. When the transmission rod is driven to rotate back and forth in the circumferential direction by the drive shaft, the transmission rod then drives the brush disk to rotate back and forth through the L-shaped linkage rod and the rotating seat.

[0012] Furthermore, the rotating base has an outer cylindrical surface and mating holes distributed axially along the outer cylindrical surface. The connecting shaft on the brush plate is inserted into the mating hole. The upper part of the brush rod has an inner cylindrical surface that mates with the outer cylindrical surface. The connecting shaft has a radially distributed limiting groove in its middle. The upper part of the brush rod is also pivotally connected to a first limiting pin parallel to the axial direction of the outer cylindrical surface. The first limiting pin has a radial limiting protrusion. Rotating the first limiting pin causes the radial limiting protrusion to engage with or disengage from the limiting groove. The rotating base has a connecting hole, and one end of the L-shaped linkage rod is inserted into the connecting hole. In this way, when the bristles on the electric toothbrush head wear down, only the brush plate and bristles need to be replaced, instead of replacing the entire electric toothbrush head, which can effectively reduce the cost of using the electric toothbrush.

[0013] Furthermore, the upper part of the brush rod is also equipped with a second limiting pin that is perpendicular to the axial direction of the outer cylindrical surface. The second limiting pin locks the rotating seat so that the rotating seat cannot detach from the brush rod.

[0014] Furthermore, a tension spring is installed between the first limiting pin and the brush rod. One end of the tension spring is connected to the first limiting pin, and the other end is connected to the brush rod. The tension of the spring allows the radial limiting protrusion to stably engage with the limiting groove. A latch is provided at the rear end of the first limiting pin, and a through hole corresponding to the latch is provided at the upper rear end of the brush rod. A key can be inserted through the through hole into the latch to rotate the first limiting pin. This allows for faster replacement of the brush disc and bristles.

[0015] Furthermore, the brush rod includes a head, a middle support, and a locking part. The lower end of the head is sleeved with the upper end of the middle support, and the locking part is locked with the middle support. The transmission rod is pivotally connected inside the middle support, and the axial direction of the transmission rod is limited by the middle support and the locking part. The rotating seat is mounted on the head, and the through hole corresponding to the locking slot is provided on the head. A hinge seat is provided inside the head, and the middle part of the first limiting pin is pivotally connected to the hinge seat, and the rear end of the first limiting pin is engaged with the through hole corresponding to the locking slot.

[0016] Furthermore, the rotating base has an outer cylindrical surface and mating holes axially distributed along the outer cylindrical surface. The connecting shaft on the brush plate is inserted into the mating hole. The upper part of the brush handle has an inner cylindrical surface that mates with the outer cylindrical surface. The rear end of an elastic part is connected to the rear part of the connecting shaft, and the front end of the elastic part has a limiting protrusion. The upper part of the brush handle has a limiting through hole. When the limiting protrusion engages with the limiting through hole, it restricts the axial displacement of the connecting shaft. Pressing down the limiting protrusion disengages it from the limiting through hole, releasing the restriction on the axial displacement of the connecting shaft. This structure also facilitates the replacement of the brush plate and bristles, reducing the operating cost of the electric toothbrush.

[0017] Furthermore, the outer surface of the rotating seat is also provided with a clearance through hole communicating with the mating hole. The limiting protrusion can extend from the clearance through hole or be pressed into the mating hole. The upper part of the brush rod is also equipped with a limiting pin perpendicular to the axial direction of the connecting shaft. The limiting pin is inserted into the clearance through hole and locks the rotating seat so that the rotating seat cannot detach from the brush rod. This not only prevents the rotating seat from detaching from the brush rod, but also allows the elastic part to move freely.

[0018] This invention uses an L-shaped linkage rod, one end of which is connected to the brush disc, and the other end of which is connected to the upper part of the transmission rod. The other end of the L-shaped linkage rod does not coincide with the rotation center axis of the transmission rod. In this way, the L-shaped linkage rod and the transmission rod work together to drive the brush disc to rotate back and forth. The transmission component has a simple structure, is easy to assemble, and has high transmission reliability. Attached Figure Description

[0019] Figure 1 This is a perspective view of a conventional electric toothbrush drive body according to the present invention;

[0020] Figure 2 This is a perspective view of the first embodiment of the present invention;

[0021] Figure 3 yes Figure 2 Hidden brush handle 3D view;

[0022] Figure 4 This is a top view of the first embodiment of the present invention;

[0023] Figure 5 yes Figure 4 AA section view;

[0024] Figure 6 yes Figure 4 BB cross-sectional view;

[0025] Figure 7 This is a perspective view of the brush rod according to the first embodiment of the present invention;

[0026] Figure 8 yes Figure 7 3D exploded view of the brush handle;

[0027] Figure 9 This is the first embodiment of the present invention and Figure 1 A partial cross-sectional view of the electric toothbrush drive unit;

[0028] Figure 10 A perspective view of the second embodiment of the present invention;

[0029] Figure 11 yes Figure 10 Hidden brush handle 3D view;

[0030] Figure 12 This is a top view of the second embodiment of the present invention;

[0031] Figure 13 yes Figure 12 CC section view;

[0032] Figure 14 yes Figure 12 DD sectional view;

[0033] Figure 15 This is a perspective view of the brush rod according to the second embodiment of the present invention;

[0034] Figure 16 This is a perspective view of the rotating seat according to the second embodiment of the present invention;

[0035] Figure 17 This is a three-dimensional view of the brush plate according to the second embodiment of the present invention;

[0036] Figure 18 This is the second embodiment of the present invention and Figure 1 A partial cross-sectional view of the electric toothbrush drive unit;

[0037] Figure 19 This is a perspective view of the third embodiment of the present invention;

[0038] Figure 20 yes Figure 19 Hidden brush handle 3D view;

[0039] Figure 21 This is a top view of the third embodiment of the present invention;

[0040] Figure 22 yes Figure 21 EE sectional view;

[0041] Figure 23 This is a perspective view of the brush rod according to the third embodiment of the present invention;

[0042] Figure 24 This is a perspective view of the rotating seat according to the third embodiment of the present invention;

[0043] Figure 25This is a three-dimensional view of the brush plate according to the third embodiment of the present invention. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0045] Example 1 Figures 1 to 9 As shown, an electric toothbrush head includes a brush handle 1 and a brush disc 2. The brush handle 1 has a cavity 1a in the middle, which connects one side of the upper end of the brush handle 1 and the lower end face of the brush handle 1. The brush disc 2 has bristles 2a fixedly connected to it. The brush disc 2 is connected to the upper end of the brush handle 1 and can rotate relative to the brush handle 1. A transmission rod 3 is installed in the cavity 1a of the brush handle 1. One end of an L-shaped linkage rod 4 is connected to the brush disc 2, and the other end of the L-shaped linkage rod 4 is connected to the upper part of the transmission rod 3. The other end of the L-shaped linkage rod 4 does not coincide with the rotation center axis of the transmission rod 3. When the electric toothbrush head is installed on the electric toothbrush drive body 100, the lower part of the transmission rod 3 is connected to the drive shaft 10 of the electric toothbrush drive body 100. The transmission rod 3 is driven to rotate back and forth in the circumferential direction through the drive shaft 10. The transmission rod 3 then drives the brush disc 2 to rotate back and forth through the L-shaped linkage rod 4.

[0046] More specifically, the transmission rod 3 has a first connecting hole 31 on its upper part. The central axis of the first connecting hole 31 is parallel to but does not coincide with the rotation center axis of the transmission rod 3. The first connecting hole 31 is a through hole. The brush plate 2 has a second connecting hole 21. The central axis of the second connecting hole 21 is parallel to but does not coincide with the rotation center axis of the brush plate 2. The second connecting hole 21 is a blind hole. One end of the L-shaped linkage rod 4 is inserted into the second connecting hole 21, and the other end is inserted into the first connecting hole 31.

[0047] The brush rod 1 includes a head 11, a middle support 12, and a locking part 13. The lower end of the head 11 is sleeved with the upper end of the middle support 12, and the locking part 13 is locked with the middle support 12. The middle support 12 has a through groove 12a in the lower part, and locking recesses 12b are provided on both inner sides of the through groove 12a. Locking hooks 13a are provided on both sides of the locking part 13. The locking part 13 is partially embedded in the through groove 12a, and each locking hook 13a cooperates with a locking recess 12b. The transmission rod 3 is pivotally connected in the middle support 12, and the axial direction of the transmission rod 3 is limited by the middle support 12 and the locking part 13.

[0048] The head 11 is provided with a plurality of elastic snap-fit ​​protrusions 111, and the free end of the snap-fit ​​protrusions 111 is provided with a hook 112. The inner surfaces of the plurality of snap-fit ​​protrusions 111 are on the same cylindrical surface. The brush disk 2 extends outward from the side away from the bristles 2a by a pivot shaft 2b. The pivot shaft 2b is provided with an annular positioning groove 21b in the middle. The outer circumferential surface of the pivot shaft 2b cooperates with the inner surfaces of the plurality of snap-fit ​​protrusions 111. The hook 112 on each snap-fit ​​protrusion 111 is engaged in the annular positioning groove 21b.

[0049] The lower end of the transmission rod 3 is provided with a connecting recess 32, and the inner side of the connecting recess 32 is provided with a snap-fit ​​protrusion 33. The snap-fit ​​part 13 is provided with a protrusion 131 that fits into the connecting recess 32. The protrusion 131 extends upward from one end face 132 of the snap-fit ​​part 13. The connecting recess 32 on the transmission rod 3 fits into the protrusion 131, and the lower end of the transmission rod 3 abuts against the end face 132. The snap-fit ​​part 13 is also provided with a through hole 133 corresponding to the connecting recess 32. The outer circumferential surface of the drive shaft 10 is provided with a snap-fit ​​groove 101. When the drive shaft 10 passes through the through hole 133 and is inserted into the connecting recess 32, the snap-fit ​​protrusion 33 cooperates with the snap-fit ​​groove 101.

[0050] The transmission rod 3 has a limiting shoulder 34 on its outer circumferential surface in the middle, and a limiting part 121 is provided inside the intermediate support part 12. The limiting part 121 cooperates with the limiting shoulder 34. The axial direction of the transmission rod 3 is limited by the limiting part 121 of the intermediate support part 12 and the end face 132 of the locking part 13.

[0051] The brush rod 1 and brush disc 2 can be injection molded.

[0052] When using this embodiment, as follows: Figure 9 As further shown, the drive shaft 10 of the electric toothbrush drive body 100 is inserted into the connecting recess 32 at the lower end of the transmission rod 3. The snap-fit ​​groove 101 on the outer circumferential surface of the drive shaft 10 cooperates with the snap-fit ​​protrusion 33 on the transmission rod 3. The lower part of the brush rod 1 cooperates with and is relatively fixed to the outer shell of the electric toothbrush drive body 100. When the switch 100a of the electric toothbrush drive body 100 is pressed, the drive shaft 10 rotates back and forth in the circumferential direction. The transmission rod 3 is driven to rotate back and forth in the circumferential direction through the drive shaft 10. The transmission rod 3 then drives the brush plate 2 to rotate back and forth through the L-shaped linkage rod 4. In this way, the brush plate 2 can drive the bristles 2a to rotate back and forth for electric brushing.

[0053] Example 2 Figures 10 to 18 As shown, an electric toothbrush head differs from Embodiment 1 in that: a rotating seat 5 is pivotally connected to the upper part of the brush rod 1, and a connecting shaft 21 extends outward from the rear of the brush disc 2. The connecting shaft 21 is connected to the rotating seat 5 in an axially movable and circumferentially fixed manner. One end of the L-shaped linkage rod 4 is first connected to the brush disc 2 through the connecting rotating seat 5. When the transmission rod 3 is driven to rotate back and forth in the circumferential direction by the drive shaft 10, the transmission rod 3 then drives the brush disc 2 to rotate back and forth through the L-shaped linkage rod 4 and the rotating seat 5.

[0054] More specifically, the rotating seat 5 has an outer cylindrical surface 51 and mating holes 52 distributed axially along the outer cylindrical surface 51. The connecting shaft 21 on the brush plate 2 is inserted into the mating hole 52. The upper part of the brush rod 1, i.e., the upper head 11 of the brush rod 1, is provided with an inner cylindrical surface 111, which mates with the outer cylindrical surface 51. The rotating seat 5 can be injection molded. The connecting shaft 21 is provided with a radially distributed limiting groove 211 in the middle. The upper part of the brush rod 1 is also pivotally connected to a first limiting pin 6 parallel to the axial direction of the outer cylindrical surface 51. The head of the brush rod 1 is provided with a hinge seat 112. The middle part of the first limiting pin 6 is pivotally connected to the hinge seat 112. The first limiting pin 6 is provided with a radial limiting protrusion 61. Rotating the first limiting pin 6 causes the radial limiting protrusion 61 to engage with or disengage from the limiting groove 211.

[0055] The upper part of the brush rod 1, i.e. the upper head 11 of the brush rod 1, is also equipped with a second limiting pin 7 that is perpendicular to the axial direction of the outer cylindrical surface 51. The second limiting pin 7 locks one end of the rotating seat 5 so that the rotating seat 5 cannot be disengaged from the brush rod 1.

[0056] A tension spring 8 is installed between the first limiting pin 6 and the brush rod 1. One end of the tension spring 8 is connected to the first limiting pin 6 and the other end is connected to the brush rod 1. Specifically, a connecting post 113 is provided in the head 11 of the brush rod 1, and the other end of the tension spring 8 is connected to the connecting post 113. The tension of the tension spring 8 enables the radial limiting protrusion 61 to stably fit in the limiting groove 211.

[0057] The first limiting pin 6 has a latch 62 at its rear end, and the upper part of the brush rod 1, i.e., the rear end of the head 11, has a through hole 114 corresponding to the latch 62. A key can be inserted into the latch 62 through the through hole 114 to rotate the first limiting pin 6. The rear end of the first limiting pin 6 is engaged with the through hole 114 corresponding to the latch 62.

[0058] The rotating seat 5 is also provided with a connecting hole 53, which is a through hole, and one end of the L-shaped linkage rod 4 is inserted into the connecting hole 53.

[0059] The brush rod 1 in this embodiment is the same as that in Embodiment 1, except that the head 11 is different from the head structure in Embodiment 1. The structure of the middle support part 12 and the snap-fit ​​part 13 and the connection method of the three are the same as those in Embodiment 1.

[0060] When using this embodiment, as follows: Figure 18As further shown, the drive shaft 10 of the electric toothbrush drive body 100 is inserted into the connecting recess 32 at the lower end of the transmission rod 3. The snap-fit ​​groove 101 on the outer circumferential surface of the drive shaft 10 cooperates with the snap-fit ​​protrusion 33 on the transmission rod 3. The lower part of the brush rod 1 cooperates with and is relatively fixed to the outer shell of the electric toothbrush drive body 100. When the switch 100a of the electric toothbrush drive body 100 is pressed, the drive shaft 10 rotates back and forth in the circumferential direction. The transmission rod 3 is driven to rotate back and forth in the circumferential direction through the drive shaft 10. The transmission rod 3 then drives the brush plate 2 to rotate back and forth through the L-shaped linkage rod 4 and the rotating seat 5. In this way, the brush plate 2 can drive the bristles 2a to rotate back and forth for electric brushing.

[0061] In this embodiment, the brush plate 2 with bristles 2a can be replaced separately. When the bristles 2a are worn, the key is inserted through the through hole 114 into the bayonet 62 to rotate the first limiting pin 6, causing the radial limiting protrusion 61 to disengage from the limiting groove 211, thereby releasing the restriction on the axial displacement of the connecting shaft 21. The brush plate 2 can then be removed, replaced with a new brush plate 2 with bristles 2a, and the key is then pulled out. The radial limiting protrusion 61 then engages with the limiting groove 211 again, restricting the axial displacement of the connecting shaft 21, allowing it to be reused, effectively reducing the cost of using the electric toothbrush.

[0062] Example 3 Figures 19 to 25 As shown, an electric toothbrush head differs from Embodiment 2 in that: the rear end of an elastic part 22a is connected to the rear part of the connecting shaft 22, and the front end of the elastic part 22a is provided with a limiting protrusion 22b. The upper part of the brush rod 1, i.e., the head 11 of the brush rod 1, is provided with a limiting through hole 11a. When the limiting protrusion 22b is engaged with the limiting through hole 11a, it restricts the axial displacement of the connecting shaft 22. When the limiting protrusion 22b is pressed down, the limiting protrusion 22b disengages from the limiting through hole 11a, releasing the restriction on the axial displacement of the connecting shaft 22.

[0063] The rotating seat 5 has an outer cylindrical surface 5a and a mating hole 5b distributed along the axial direction of the outer cylindrical surface 5a. The connecting shaft 22 on the brush disk 2 is inserted into the mating hole 5b. The upper part of the brush rod 1 is provided with an inner cylindrical surface 11b, which mates with the outer cylindrical surface 5a.

[0064] The outer surface of the rotating seat 5 is also provided with a clearance through hole 5c that communicates with the mating hole 5b. The limiting protrusion 22b can extend out of the clearance through hole 5c or be pressed into the mating hole 5b. The upper part of the brush rod 1, i.e. the head 11 of the brush rod 1, is also equipped with a limiting pin 11c that is perpendicular to the axial direction of the connecting shaft 22. The limiting pin 11c is inserted into the clearance through hole 5c and locks the rotating seat 5 so that the rotating seat 5 cannot be separated from the brush rod 1.

[0065] The brush plate 2, connecting shaft 22, and elastic part 22a can be integrally molded by injection molding, and the rotating seat 5 can also be molded by injection molding. The rotating seat 5 is also provided with a connecting hole 53, and one end of the L-shaped linkage rod 4 is inserted into the connecting hole 53.

[0066] In this embodiment, the connection method with the electric toothbrush drive body is the same as in Embodiment 2. When the bristles 2a wear down, the elastic part 22a is pressed down through the limiting through hole 11a with a tool, pressing the elastic part 22a into the mating hole 5b. This releases the axial displacement restriction of the connecting shaft 22, allowing the brush plate 2 with worn bristles 2a to be removed and replaced with a new brush plate 2 with bristles 2a. After the connecting shaft 22 is inserted into the mating hole 5b, the limiting protrusion 22b engages with the limiting through hole 11a due to the action of the elastic part 22a, restricting the axial displacement of the connecting shaft 22. This allows for normal use with the electric toothbrush drive body, effectively reducing the operating cost of the electric toothbrush.

[0067] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. An electric toothbrush head, comprising a brush handle and a brush disc, wherein the brush handle has a cavity in the middle, the brush disc is equipped with bristles, the brush disc is connected to the upper end of the brush handle and can rotate relative to the brush handle, characterized in that: The cavity of the brush rod contains a transmission rod, one end of an L-shaped linkage rod is connected to the brush disc, the other end of the L-shaped linkage rod is connected to the upper part of the transmission rod, and the other end of the L-shaped linkage rod does not coincide with the rotation center axis of the transmission rod. When the electric toothbrush head is installed on the electric toothbrush drive body, the lower part of the transmission rod is connected to the drive shaft of the electric toothbrush drive body. The transmission rod is driven to rotate back and forth in the circumferential direction through the drive shaft, and the transmission rod then drives the brush plate to rotate back and forth through the L-shaped linkage rod. The brush rod includes a head, a middle support, and a locking part. The lower end of the head is sleeved with the upper end of the middle support, and the locking part is locked with the middle support. The transmission rod is pivotally connected inside the middle support, and the axial direction of the transmission rod is limited by the middle support and the locking part. The upper part of the transmission rod is provided with a first connecting hole, the central axis of the first connecting hole is parallel to but does not coincide with the rotation center axis of the transmission rod, and the brush plate is provided with a second connecting hole, the central axis of the second connecting hole is parallel to but does not coincide with the rotation center axis of the brush plate; one end of the L-shaped linkage rod is inserted into the second connecting hole and the other end is inserted into the first connecting hole.

2. The electric toothbrush head according to claim 1, characterized in that: The head is provided with multiple elastic snap-fit ​​protrusions, and the free end of each snap-fit ​​protrusion is provided with a hook. The inner surfaces of the multiple snap-fit ​​protrusions are on the same cylindrical surface. A pivot shaft extends outward from the side of the brush disc away from the bristles. The pivot shaft is provided with an annular positioning groove in the middle. The outer circumferential surface of the pivot shaft cooperates with the inner surfaces of the multiple snap-fit ​​protrusions. The hook on each snap-fit ​​protrusion cooperates with the annular positioning groove.

3. An electric toothbrush head according to claim 1, characterized in that: The lower end of the transmission rod is provided with a connecting recess, and the inner side of the connecting recess is provided with a snap-fit ​​protrusion. The snap-fit ​​part is provided with a protrusion that fits into the connecting recess. The snap-fit ​​part is also provided with a through hole corresponding to the connecting recess. The outer circumferential surface of the drive shaft is provided with a snap-fit ​​groove. When the drive shaft passes through the through hole and is inserted into the connecting recess, the snap-fit ​​protrusion and the snap-fit ​​groove cooperate. The transmission rod has a limiting shoulder on its outer circumference and a limiting part inside the middle support part. The limiting part cooperates with the limiting shoulder.

4. An electric toothbrush head according to claim 1, characterized in that: A rotating seat is pivotally connected to the upper part of the brush rod. A connecting shaft extends outward from the rear of the brush disk. The connecting shaft is connected to the rotating seat in an axially movable and circumferentially fixed manner. One end of the L-shaped linkage rod is connected to the brush disk through the connecting rotating seat. When the transmission rod is driven to rotate back and forth in the circumferential direction by the drive shaft, the transmission rod then drives the brush disk to rotate back and forth through the L-shaped linkage rod and the rotating seat.

5. An electric toothbrush head according to claim 4, characterized in that: The rotating seat has an outer cylindrical surface and mating holes distributed axially along the outer cylindrical surface. The connecting shaft on the brush plate is inserted into the mating hole. The upper part of the brush rod is provided with an inner cylindrical surface, which mates with the outer cylindrical surface. The connecting shaft has a radially distributed limiting groove in the middle, and the upper part of the brush rod is also pivotally connected to a first limiting pin parallel to the axial direction of the outer cylindrical surface. The first limiting pin has a radial limiting protrusion. Rotating the first limiting pin causes the radial limiting protrusion to engage with or disengage from the limiting groove. The rotating seat is provided with a connecting hole, and one end of the L-shaped linkage rod is inserted into the connecting hole.

6. An electric toothbrush head according to claim 5, characterized in that: The upper part of the brush rod is also equipped with a second limiting pin that is perpendicular to the axial direction of the outer cylindrical surface. The second limiting pin locks the rotating seat so that the rotating seat cannot detach from the brush rod.

7. An electric toothbrush head according to claim 5, characterized in that: A tension spring is installed between the first limiting pin and the brush rod. One end of the tension spring is connected to the first limiting pin and the other end is connected to the brush rod. The tension of the tension spring enables the radial limiting protrusion to stably fit in the limiting groove. The first limiting pin has a slot at its rear end, and the upper rear end of the brush rod has a through hole corresponding to the slot. A key can be inserted into the slot through the through hole to rotate the first limiting pin.

8. An electric toothbrush head according to claim 7, characterized in that: The brush rod includes a head, a middle support, and a locking part. The lower end of the head is sleeved with the upper end of the middle support, and the locking part is locked with the middle support. The transmission rod is pivotally connected inside the middle support, and the axial direction of the transmission rod is limited by the middle support and the locking part. The rotating seat is mounted on the head, and the through hole corresponding to the locking slot is provided on the head. A hinge seat is provided inside the head, and the middle part of the first limiting pin is pivotally connected to the hinge seat, and the rear end of the first limiting pin is engaged with the through hole corresponding to the locking slot.

9. An electric toothbrush head according to claim 4, characterized in that: The rotating seat has an outer cylindrical surface and mating holes distributed axially along the outer cylindrical surface. The connecting shaft on the brush plate is inserted into the mating hole. The upper part of the brush rod is provided with an inner cylindrical surface, which mates with the outer cylindrical surface. The rear end of an elastic part is connected to the rear part of the connecting shaft, and the front end of the elastic part is provided with a limiting protrusion. The upper part of the brush rod is provided with a limiting through hole. When the limiting protrusion is engaged with the limiting through hole, it restricts the axial displacement of the connecting shaft. When the limiting protrusion is pressed down, the limiting protrusion disengages from the limiting through hole and releases the restriction on the axial displacement of the connecting shaft.

10. An electric toothbrush head according to claim 9, characterized in that: The outer surface of the rotating seat is also provided with a clearance through hole that connects to the mating hole, and the limiting protrusion can extend out of the clearance through hole or be pressed into the mating hole; The upper part of the brush rod is also equipped with a limiting pin that is perpendicular to the axis of the connecting shaft. The limiting pin is inserted into the clearance through hole and locks the rotating seat so that the rotating seat cannot be disengaged from the brush rod.

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