A dental handpiece

Abstract

This utility model relates to the field of medical device technology, specifically to a dental curved handpiece. The dental curved handpiece includes a head assembly, a transmission assembly, a liner assembly, a screw, and a curved handle. The transmission assembly and the liner assembly are embedded in the curved handle at a preset bending angle. The bottom end of the liner assembly abuts against the curved handle, and the top end of the liner assembly abuts against the transmission assembly. One end of the head assembly engages with the transmission assembly for transmission, and the other end extends beyond the top end of the head assembly. A limiting groove is formed on the outer wall of the head assembly. One end of the screw abuts against the limiting groove, and the other end is embedded in the bottom end of the curved handle. The screw is threadedly connected to the transmission assembly, and their axes are parallel. The angle between the screw and the head assembly is a preset bending angle, allowing the top end of the screw to extend into the limiting groove. By abutting against the inner wall of the limiting groove and / or the corner of the groove bottom, the screw axially limits the head assembly, preventing it from dislodging from the curved handle during treatment.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a dental curved handpiece. Background Technology

[0002] Dental handpieces, commonly used medical instruments in oral treatment, play a crucial role in clinical practice. The curved design of the handpiece head relative to the handle allows for easier access to deeper parts of the oral cavity for examination and treatment. Drilling and cutting are then performed using burs connected to the handpiece head.

[0003] Dental curved handpieces typically use threaded connections between their segments and the handle, such as internal and external threads or snap-fit ​​connections secured with bolts. After each use, dental curved handpieces require cleaning and disinfection. However, the threaded connection between the handle and the handpiece head easily traps impurities such as blood, saliva, and plaque generated during treatment. These impurities seep into the threaded gaps, increasing the difficulty of cleaning. Furthermore, the threaded connection method is cumbersome to install and remove, increasing the time and operational difficulty for medical staff when changing the handpiece head or performing equipment maintenance. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a dental curved handpiece, which solves the technical problems of difficult cleaning of the threaded connection of the existing threaded dental curved handpiece and cumbersome disassembly and assembly of the threaded connection.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the dental handpiece of this utility model includes a head assembly, a transmission assembly, an inner liner assembly, a screw, and a bent handle.

[0008] The transmission component and the inner lining component are embedded in the elbow handle at a preset bending angle; the bottom end of the inner lining component abuts against the elbow handle, and the top end of the inner lining component abuts against the transmission component.

[0009] One end of the head assembly engages with the transmission assembly for transmission, and the other end extends out from the top of the head assembly;

[0010] A limiting groove is formed on the outer wall of the machine head assembly; one end of the screw abuts against the limiting groove, and the other end is built into the bottom end of the elbow handle; the screw is threadedly connected to the transmission assembly, and the axes of the two are parallel.

[0011] Optionally, the head assembly includes a head, a core shaft, a drive shaft, a second gear, a third gear, and a retaining sleeve;

[0012] The movement shaft is built into the headstock;

[0013] The second gear and the third gear are respectively disposed at both ends of the transmission shaft; the second gear meshes with the movement shaft for transmission, and the axes of the two are perpendicular to each other;

[0014] The fixing sleeve is fitted onto the drive shaft; the limiting groove is formed on the outer wall of the fixing sleeve.

[0015] Optionally, a tapered groove is also provided on the outer wall of the fixing sleeve;

[0016] The conical groove is connected to the limiting groove; the top end of the screw abuts against the conical groove.

[0017] Optionally, the transmission assembly includes a fourth gear, a bearing housing, a connecting shaft, a first spring, and a shift fork;

[0018] The bearing housing is sleeved on the connecting shaft, and the two are rotatably connected; the bottom end of the bearing housing abuts against the top end of the inner liner assembly; the first spring and the shift fork are both built into the inner liner assembly; the screw is threadedly connected to the bearing housing.

[0019] One end of the connecting shaft passes through the bearing housing and is connected to the fourth gear, while the other end is connected to the shift fork.

[0020] The first spring is sleeved on the connecting shaft; one end of the first spring is connected to the bearing seat sleeve, and the other end is connected to the shift fork.

[0021] Optionally, the liner assembly includes a bushing, a water pipe, and an air pipe;

[0022] The bottom end of the bushing abuts against the bottom end of the elbow handle, and the top end abuts against the transmission assembly;

[0023] One end of the water pipe and one end of the air pipe are connected to the bushing, and the other end of the water pipe and the other end of the air pipe are connected to the head assembly.

[0024] Optionally, the dental handpiece also includes an optical fiber;

[0025] One end of the optical fiber passes through the inner liner assembly and exits the bottom end of the elbow handle; the other end of the optical fiber passes through the top outer wall of the elbow handle.

[0026] The optical fiber is positioned between the water pipe and the gas pipe.

[0027] Optionally, the liner assembly further includes a second spring and a paddle;

[0028] The paddle is slidably connected to the bottom outer wall of the bushing along the axial direction of the bushing;

[0029] One end of the second spring is connected to the bushing, and the other end is connected to the top of the lever; the second spring is capable of extending and retracting along the axial direction of the bushing.

[0030] The transmission assembly has a first clearance groove; the bushing has a second clearance groove; the screw passes through the first clearance groove and the second clearance groove in sequence;

[0031] The lever is provided with a U-shaped groove; the bottom end of the screw is located inside the U-shaped groove.

[0032] Optionally, the elbow handle includes a locking nut and an elbow section and a grip section connected at the preset bending angle;

[0033] The head assembly is located inside the bend section; the transmission assembly and the liner assembly are built into the grip section;

[0034] The bottom outer wall of the grip section is provided with an external thread, which is threadedly connected to the locking nut; the locking nut abuts against the bottom end of the inner liner assembly.

[0035] (III) Beneficial Effects

[0036] The beneficial effects of this utility model are:

[0037] The screw is parallel to the axis of the transmission assembly, creating a preset bending angle between the screw and the handpiece assembly. This allows the top of the screw to extend into the limiting groove. By abutting against the inner wall and / or the corner of the groove bottom, the screw axially limits the handpiece assembly, preventing it from dislodging from the curved handle during treatment. The other end of the screw is integrated into the bottom of the curved handle, allowing rotation to engage or disengage it from the limiting groove, thus locking or unlocking it. Compared to existing threaded connection structures, this invention allows locking or unlocking the handpiece assembly simply by turning the screw, eliminating the need for disassembly. This reduces the time and difficulty for medical personnel when changing the handpiece or performing equipment maintenance. Furthermore, the threaded connection of the screw is far from the head of the handpiece assembly, making it difficult for impurities generated during treatment to enter the threaded connection. This eliminates the need for cleaning the threaded connection, significantly reducing the difficulty of cleaning the dental handpiece. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the dental curved handpiece of this utility model;

[0039] Figure 2This is an exploded view of the dental curved handpiece of this utility model;

[0040] Figure 3 This is a cross-sectional schematic diagram of the dental curved handpiece of this utility model;

[0041] Figure 4 This is an exploded view of the head assembly of this utility model;

[0042] Figure 5 This is a schematic diagram of the transmission component of this utility model;

[0043] Figure 6 This is a front view of the connection between the head assembly and the transmission assembly of this utility model.

[0044] Figure 7 This is a bottom view showing the connection between the head assembly and the transmission assembly of this utility model;

[0045] Figure 8 This is a perspective view showing the connection between the head assembly and the transmission assembly of this utility model.

[0046] [Explanation of Labels in the Attached Image]

[0047] 1: Head assembly; 11: Head; 12: Core shaft; 13: Drive shaft; 14: Second gear; 15: Third gear; 16: Fixing sleeve; 161: Limiting groove; 162: Tapered groove; 17: End cover;

[0048] 2: Transmission assembly; 21: Fourth gear; 22: Bearing housing; 221: First clearance groove; 222: Threaded hole; 23: Connecting shaft; 24: First spring; 25: Shift fork;

[0049] 3: Inner liner assembly; 31: Bushing; 311: Second clearance groove; 32: Water pipe; 33: Air pipe; 34: Second spring; 35: Paddle; 351: U-shaped groove;

[0050] 4: Screw;

[0051] 5: Elbow handle; 51: Locking nut; 52: Elbow section; 53: Grip section; 531: External thread;

[0052] 6: Fiber optic cable. Detailed Implementation

[0053] To better explain and facilitate understanding of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0055] Furthermore, in this utility model, the use of terms such as "first," "second," etc., is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0056] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; "connection" can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0057] See Figures 1 to 3 This utility model provides a dental curved handpiece, which includes a head assembly 1, a transmission assembly 2, an inner liner assembly 3, a screw 4, and a curved handle 5. The transmission assembly 2 and the inner liner assembly 3 are embedded in the curved handle 5 at a preset bending angle. The bottom end of the inner liner assembly 3 abuts against the curved handle 5, and the top end of the inner liner assembly 3 abuts against the transmission assembly 2. One end of the head assembly 1 is engaged with the transmission assembly 2 for transmission, and the other end extends out of the top end of the head assembly 1. A limiting groove 161 is formed on the outer wall of the head assembly 1. One end of the screw 4 abuts against the limiting groove 161, and the other end is embedded in the bottom end of the curved handle 5. The screw 4 is threadedly connected to the transmission assembly 2, and the axes of the two are parallel.

[0058] The curved handle 5 has openings at both its top and bottom. The top opening connects to the head assembly 1, and the bottom opening connects to an external motor. The external motor extends into the curved handle 5 through the bottom opening and engages with the inner liner assembly 3. The output shaft of the external motor is connected to the transmission assembly 2. When the transmission assembly 2 rotates, it drives the head assembly 1 to rotate, ultimately causing the bur connected to the head assembly 1 to rotate. In this embodiment, the dental curved handpiece is a low-speed dental curved handpiece. The preset bending angle can be the angle between the transmission assembly 2 and the inner liner assembly 3, or the angle between the corresponding axes of the head assembly 1 and the transmission assembly 2.

[0059] The screw 4 is threadedly connected to the transmission assembly 2, meaning the screw 4 is fixed by the transmission assembly 2. The screw 4 is parallel to the axis of the transmission assembly 2, resulting in a preset bending angle between the screw 4 and the head assembly 1. This allows the top end of the screw 4 to extend into the limiting groove 161. By abutting against the bottom of the limiting groove 161 and / or the bottom corner of the limiting groove 161, the screw 4 axially limits the head assembly 1, preventing it from dislodging from the curved handle 5 during treatment. The other end of the screw 4 is built into the bottom of the curved handle 5, allowing rotation at the bottom of the curved handle 5 to move the screw 4 against or away from the limiting groove 161, thus locking or unlocking the limiting groove 161. Compared to existing threaded connection structures, the screw 4 of this invention can lock or unlock the handpiece assembly 1 simply by turning it. The screw 4 does not need to be disassembled, reducing the time cost and operational difficulty for medical staff to replace the handpiece or perform equipment maintenance. At the same time, the threaded connection structure of the screw 4 is far away from the head end of the handpiece assembly 1 (the head end of the handpiece assembly 1 is equipped with a sealing ring and other sealing structures). Therefore, impurities generated during treatment are difficult to enter the threaded connection of the screw 4, eliminating the need to clean the threaded connection structure and greatly reducing the cleaning difficulty of the dental handpiece.

[0060] like Figure 4 As shown, the head assembly 1 includes a head 11, a core shaft 12, a drive shaft 13, a second gear 14, a third gear 15, and a fixing sleeve 16. The core shaft 12 is built into the head 11. The second gear 14 and the third gear 15 are correspondingly located at both ends of the drive shaft 13. The second gear 14 meshes with the core shaft 12, and their axes are perpendicular. The fixing sleeve 16 is sleeved on the drive shaft 13. A limiting groove 161 is formed on the outer wall of the fixing sleeve 16. Specifically, the first gear is sleeved on the core shaft 12, and the first gear meshes with the second gear 14. The needle is inserted into the inside of the core shaft 12, so that the drive shaft 13 can drive the needle to rotate when it rotates. The shape of the fixing sleeve 16 is adapted to the shape of the corresponding installation position of the head assembly 1, so that the outer wall of the fixing sleeve 16 fits the inner wall of the head assembly 1, effectively preventing the head assembly 1 from shifting due to vibration during treatment. The bottom end of the fixing sleeve 16 is located at the bend of the elbow handle 5, creating a certain gap between the bottom end of the fixing sleeve 16 and the inner wall of the elbow handle 5. The top end of the screw 4 can extend into the limiting groove 161 through this gap and abut against the limiting groove 161 for limiting. Optionally, the head assembly 1 also includes an end cover 17, which is elastically connected to the head 11. Pressing the end cover disengages the insert from the movement shaft 12, facilitating the replacement of the insert.

[0061] Furthermore, a conical groove 162 is also provided on the outer wall of the fixing sleeve 16; the conical groove 162 communicates with the limiting groove 161; the top end of the screw 4 abuts against the conical groove 162. In this embodiment, the limiting groove 161 is a square groove, and only the bottom of the limiting groove 161 and / or the bottom corner of the limiting groove 161 abut against the screw 4, resulting in a small contact area. By adding a conical groove 162, the large-diameter end of the conical groove 162 communicates with the limiting groove 161, while the small-diameter end is away from the limiting groove 161, allowing the screw 4 to extend into the conical groove 162 and abut against and limit its position, further enhancing the limiting strength of the screw 4 on the fixing sleeve 16 and improving the shock resistance of the head assembly 1 during treatment.

[0062] See Figure 5 The transmission assembly 2 includes a fourth gear 21, a bearing housing 22, a connecting shaft 23, a first spring 24, and a shift fork 25. The bearing housing 22 is fitted onto the connecting shaft 23, and the two are rotatably connected. The bottom end of the bearing housing 22 abuts against the top end of the inner liner assembly 3. The first spring 24 and the shift fork 25 are both built into the inner liner assembly 3. The screw 4 is threadedly connected to the bearing housing 22. One end of the connecting shaft 23 passes through the bearing housing 22 and connects to the fourth gear 21, while the other end connects to the shift fork 25. The first spring 24 is fitted onto the connecting shaft 23. One end of the first spring 24 connects to the bearing housing 22, and the other end connects to the shift fork 25. Specifically, the bearing housing 22 contains a bearing, which is rotatably connected to the connecting shaft 23. The bottom end of the bearing housing 22 is embedded in the top groove of the inner liner assembly 3, facilitating quick assembly and disassembly and precise positioning of both components. The external motor is engaged with the inner liner assembly 3 via the bottom end of the elbow handle 5. The output shaft of the external motor is engaged with the shift fork 25. The external motor sequentially drives the shift fork 25, the fourth gear 21, the third gear 15, the second gear 14, the first gear, the movement shaft 12, and the needle to rotate. The first spring 24 can apply an axial force to the shift fork 25, improving the stability of the connection between the shift fork 25 and the output shaft of the external motor, and ensuring the stability of the transmission. Secondly, the outer wall of the bearing housing 22 is provided with a first clearance groove 221 and a threaded hole 222. The first clearance groove 221 is used to avoid clearance with the screw 4, and the threaded hole 222 is threadedly connected to the threaded section on the screw 4 to realize the axial movement of the screw 4.

[0063] like Figure 6 and Figure 7As shown, the inner liner assembly 3 includes a bushing 31, a water pipe 32, and an air pipe 33. The bottom end of the bushing 31 abuts against the bottom end of the elbow handle 5, and the top end abuts against the transmission assembly 2. One end of the water pipe 32 and one end of the air pipe 33 are connected to the bushing 31, and the other ends of the water pipe 32 and the air pipe 33 are connected to the machine head assembly 1. Specifically, water and atomized air are introduced into the water pipe 32 and the air pipe 33 through the bushing 31, and the water and atomized air are delivered to the machine head 11 for spraying out to cool and rinse the needle. In this embodiment, the water pipe 32 and the air pipe 33 are arranged on one side of the inner wall of the elbow handle 5, and the screw 4 is arranged on the other side of the inner wall of the elbow handle 5. The spatial layout is reasonable and easy to disassemble and assemble.

[0064] Furthermore, the dental handpiece also includes an optical fiber 6; one end of the optical fiber 6 passes through the inner liner assembly 3 and exits the bottom end of the elbow handle 5; the other end of the optical fiber 6 exits the top outer wall of the elbow handle 5; the optical fiber 6 is positioned between the water pipe 32 and the air pipe 33. Specifically, the optical fiber 6, water pipe 32, and air pipe 33 are all located on the same side of the inner wall of the elbow handle 5. The optical fiber 6 guides the light from the external motor to the handpiece head 11 for initial illumination. The optical fiber 6, water pipe 32, and air pipe 33 are all in a bent straight line shape, with a short path, facilitating disassembly and assembly as well as media delivery.

[0065] like Figure 8 As shown, the inner liner assembly 3 also includes a second spring 34 and a lever 35; the lever 35 is slidably connected to the bottom outer wall of the bushing 31 along the axial direction of the bushing 31; one end of the second spring 34 is connected to the bushing 31, and the other end is connected to the top of the lever 35; the second spring 34 can extend and retract along the axial direction of the bushing 31; a first clearance groove 211 is provided on the bearing seat sleeve 22; a second clearance groove 311 is provided on the bushing 31; the screw 4 passes through the first clearance groove 211 and the second clearance groove 311 in sequence; a U-shaped groove 351 is provided on the lever 35; the bottom end of the screw 4 is located inside the U-shaped groove 351. Specifically, in the original position, the bottom surface height of the lever 53 is lower than the bottom surface height of the screw 4, which can effectively prevent the screw 4 from moving axially due to external collisions, thereby ensuring the limiting stability of the screw 4 on the head assembly 1. When it is necessary to unlock the machine head assembly 1, press the lever 35 to expose the bottom surface of the screw 4 through the U-shaped groove 351. Tighten the screw 4 to adjust its axial direction, thereby disengaging it from the limiting groove 161 and unlocking the machine head assembly 1. The machine head assembly 1 can then be pulled out from the top opening of the elbow handle 5. Optionally, both the first clearance groove 211 and the second clearance groove 311 are engaged with the screw 4, so that the screw 4 serves as the installation reference for the first clearance groove 211 and the second clearance groove 311, improving the installation accuracy of the external motor, the inner liner assembly 3, and the transmission assembly 2.

[0066] In addition, the elbow handle 5 includes a locking nut 51 and an elbow section 52 and a grip section 53 connected at a preset bending angle; the head assembly 1 is partially disposed inside the elbow section 52, and the bottom end of the head 11 is engaged and sealed with the top end of the elbow section 52; the transmission assembly 2 and the inner liner assembly 3 are built into the grip section 53; an external thread 531 is provided on the outer wall of the bottom end of the grip section 53, and the external thread 531 is threadedly connected to the locking nut 51; the locking nut 51 abuts against the bottom end of the inner liner assembly 3. In this embodiment, the elbow section 52 and the grip section 53 are injection molded as a single piece, without the need for machining. Compared with CNC machining, this simplifies the manufacturing process of the elbow handle, improves the molding accuracy of the actual preset bending angle of the elbow handle 5 relative to the theoretical preset bending angle, enhances the overall shock resistance and transmission stability of the dental handpiece, and ensures the consistency of the production and assembly of the elbow handle 5.

[0067] When installing a dental curved handpiece, first connect the screw 4 to the transmission assembly 2 via threads; then embed or abut the transmission assembly 2 at the top of the inner liner assembly 3, with the screw 4 simultaneously inserted into the first clearance groove 211, the second clearance groove 311, and the U-shaped groove 351; the screw 4, transmission assembly 2, and inner liner assembly 3 are then inserted into the curved handle 5 via the bottom end of the grip section 53, and the locking nut 51 is installed and tightened on the external thread 531; the optical fiber 6 and the handpiece assembly 1 are installed sequentially from the opening at the top of the curved section 52, with the water pipe 32 and air pipe 33 correspondingly connected to the docking holes at the bottom of the handpiece 11; according to treatment needs, install the corresponding type of bur on the mandrel 12. Disassembly of the dental curved handpiece is similar and will not be described further. This invention provides a convenient dental curved handpiece for assembly and disassembly, facilitates cleaning, and reduces the time and operational difficulty for medical personnel when replacing the handpiece or performing equipment maintenance.

[0068] It should be understood that the above description of the specific embodiments of this utility model is only for illustrating the technical route and features of this utility model, and its purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. However, this utility model is not limited to the specific embodiments described above. All changes or modifications made within the scope of the claims of this utility model should be covered by the protection scope of this utility model.

Claims

1. A dental handpiece characterized by, The dental handpiece includes a head assembly (1), a transmission assembly (2), a liner assembly (3), a screw (4), and a bend handle (5); The transmission assembly (2) and the inner lining assembly (3) are built into the elbow handle (5) at a preset bending angle; the bottom end of the inner lining assembly (3) abuts against the elbow handle (5), and the top end of the inner lining assembly (3) abuts against the transmission assembly (2). One end of the head assembly (1) engages with the transmission assembly (2) for transmission, and the other end extends out of the top of the head assembly (1); A limiting groove (161) is provided on the outer wall of the head assembly (1); one end of the screw (4) abuts against the limiting groove (161), and the other end is built into the bottom end of the elbow handle (5); the screw (4) is threadedly connected to the transmission assembly (2), and the axes of the two are parallel.

2. The dental handpiece of claim 1, wherein, The head assembly (1) includes a head (11), a core shaft (12), a transmission shaft (13), a second gear (14), a third gear (15), and a fixing sleeve (16); The movement shaft (12) is built into the head (11); The second gear (14) and the third gear (15) are respectively disposed at both ends of the transmission shaft (13); the second gear (14) meshes with the movement shaft (12) for transmission, and the axes of the two are perpendicular to each other; The fixing sleeve (16) is sleeved on the transmission shaft (13); the limiting groove (161) is provided on the outer wall of the fixing sleeve (16).

3. The dental handpiece of claim 2, wherein, A tapered groove (162) is also provided on the outer wall of the fixing sleeve (16); The conical groove (162) is connected to the limiting groove (161); the top end of the screw (4) abuts against the conical groove (162).

4. Dental handpiece according to any one of claims 1 to 3, characterized in that The transmission assembly (2) includes a fourth gear (21), a bearing seat (22), a connecting shaft (23), a first spring (24), and a shift fork (25); The bearing seat sleeve (22) is sleeved on the connecting shaft (23) and the two are rotatably connected; the bottom end of the bearing seat sleeve (22) abuts against the top end of the inner liner assembly (3); the first spring (24) and the fork (25) are both built into the inner liner assembly (3); the screw (4) is threadedly connected to the bearing seat sleeve (22); One end of the connecting shaft (23) passes through the bearing seat (22) and is connected to the fourth gear (21), while the other end is connected to the shift fork (25). The first spring (24) is sleeved on the connecting shaft (23); one end of the first spring (24) is connected to the bearing seat (22), and the other end is connected to the pull fork (25).

5. The dental handpiece according to any one of claims 1-3, wherein, The inner lining assembly (3) includes a bushing (31), a water pipe (32), and an air pipe (33); The bottom end of the bushing (31) abuts against the bottom end of the elbow handle (5), and the top end abuts against the transmission assembly (2); One end of the water pipe (32) and one end of the air pipe (33) are connected to the bushing (31), and the other end of the water pipe (32) and the other end of the air pipe (33) are connected to the head assembly (1).

6. The dental handpiece of claim 5, wherein, The dental handpiece also includes an optical fiber (6); One end of the optical fiber (6) passes through the inner liner assembly (3) and exits the bottom end of the elbow handle (5); the other end of the optical fiber (6) passes through the top outer wall of the elbow handle (5). The optical fiber (6) is disposed between the water pipe (32) and the air pipe (33).

7. The dental handpiece of claim 5 wherein, The lining assembly (3) also includes a second spring (34) and a paddle (35); The paddle (35) and the bottom outer wall of the bushing (31) are slidably connected along the axial direction of the bushing (31); One end of the second spring (34) is connected to the bushing (31), and the other end is connected to the top of the paddle (35); the second spring (34) is capable of extending and retracting along the axial direction of the bushing (31); The transmission assembly (2) is provided with a first clearance groove (211); the bushing (31) is provided with a second clearance groove (311); the screw (4) passes through the first clearance groove (211) and the second clearance groove (311) in sequence; The paddle (35) is provided with a U-shaped groove (351); the bottom end of the screw (4) is located inside the U-shaped groove (351).

8. The dental handpiece according to any one of claims 1-3, wherein, The elbow handle (5) includes a locking nut (51), an elbow section (52) and a grip section (53) connected at the preset bending angle; The head assembly (1) is partially disposed inside the elbow section (52); the transmission assembly (2) and the liner assembly (3) are built into the grip section (53); The grip section (53) has an external thread (531) on its bottom outer wall, and the external thread (531) is threadedly connected to the locking nut (51); the locking nut (51) abuts against the bottom end of the inner liner assembly (3).

Images