Electric dental handpiece with automatic telescopic function

Abstract

The invention discloses an electric dental handpiece with an automatic telescopic function, which comprises a handle (1) and a handpiece (2), the handpiece (2) is fixedly connected with one end of the handle (1), a hollow shaft (3) and a bur mounting shaft (4) are arranged in the handpiece (2), the hollow shaft (3) is rotatably mounted in the handpiece (2), the bur mounting shaft (4) is in spline connection with the hollow shaft (3), and the hollow shaft (3) is rotatably mounted in the handpiece (2). The hollow shaft (3) is provided with a hollow needle mounting shaft (4), a needle (6) is in threaded connection with the needle mounting shaft (4), an elastic piece is arranged in the hollow shaft (3), the needle mounting shaft (4) is connected with the bottom surface of an end cover assembly (5) through a connecting piece, the end cover assembly (5) is in threaded connection with the top end of the machine head (2), and the bottom surface of the end cover assembly (5) is an inclined surface. According to the invention, the machine needle can perform reciprocating motion while rotating at a high speed, manual point contact operation is replaced, and the working efficiency is improved.

Description

Technical Field

[0001] The present invention relates to a dental handpiece, in particular to an electric dental handpiece with an automatic telescopic function. Background Art

[0002] With the improvement of people's living standards, more and more people are concerned about dental health problems. Currently, dental handpieces are required for tooth extraction, dental implantation, dental disease treatment, and dental cosmetology.

[0003] Dental handpieces are currently mainly divided into two categories. One category drives the core to rotate through high-pressure gas, and the rotation of the core drives the bur on it to rotate. The other category drives the transmission shaft through an electric motor, and the transmission shaft drives the core to rotate, and the rotation of the core drives the bur on it to rotate. However, currently, both electric-driven and high-pressure gas-driven dental handpieces can only achieve the rotation function of the bur. When dentists work, they need to use a point-touch method to drill, grind, and cut teeth. Especially when extracting impacted wisdom teeth or embedded teeth, due to the need for continuous point-touch operations, it consumes a lot of physical strength, resulting in finger fatigue of dentists holding the dental handpiece and low work efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide an electric dental handpiece with an automatic telescopic function to solve the technical problems in the prior art. It can make the bur rotate at a high speed while generating a reciprocating motion, replacing manual point-touch operations and improving work efficiency.

[0005] The present invention provides an electric dental handpiece with an automatic telescopic function, including a handle and a head. The head is fixedly connected to one end of the handle. A hollow shaft and a bur mounting shaft are arranged in the head. The hollow shaft is rotatably mounted in the head. The bur mounting shaft is splined to the hollow shaft. The bur is threadedly connected to the bur mounting shaft. An elastic member is installed in the hollow shaft. The bur mounting shaft is connected to the bottom surface of the end cap assembly through a connecting member. The end cap assembly is threadedly connected to the top end of the head. The bottom surface of the end cap assembly is an inclined surface.

[0006] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, an annular limiting boss is provided on the inner wall of the lower end of the head, and a thread is provided on the inner wall of the upper end of the head.

[0007] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, the interior of the hollow shaft has a stepped cavity structure that is larger at the top and smaller at the bottom, and several internal splines are provided on the inner wall of the upper part of the hollow shaft.

[0008] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, a first bearing is installed on the outer wall of the upper end of the hollow shaft, a second bearing is installed on the outer wall of the lower end of the hollow shaft, the bottom surface of the outer ring of the second bearing abuts against the annular limiting boss, a first bevel gear is further installed on the outer wall of the hollow shaft, a transmission shaft is rotatably installed in the handle, a second bevel gear is provided at the end of the transmission shaft, and the second bevel gear meshes with the first bevel gear.

[0009] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, a bur guiding shaft is fixedly provided at the lower end of the hollow shaft, a bur guiding hole is formed in the center of the bur guiding shaft, the upper end of the bur guiding shaft is a frustum structure with a larger upper part and a smaller lower part, and the lower end of the bur guiding shaft is a cylindrical structure.

[0010] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, a plurality of external splines are provided on the outer wall of the bur mounting shaft, a circular plate is fixedly provided at the top end of the bur mounting shaft, the connecting member is arranged at the edge of the top surface of the circular plate, a bur mounting hole is formed in the bur mounting shaft, internal threads are provided on the inner wall of the bur mounting hole, and the upper end of the bur is threadedly connected to the bur mounting hole.

[0011] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, the connecting member includes a connecting column, a limiting cap and a ball, the lower end of the connecting column is fixedly connected to the top surface of the circular plate, a spherical groove is formed at the top end of the connecting column, the ball is placed in the spherical groove and limited by the limiting cap, the limiting cap is threadedly connected to the upper end of the connecting column, and a through hole is formed in the limiting cap, and the diameter of the through hole is smaller than the diameter of the ball.

[0012] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, the end cap assembly includes a cover plate and a connecting cylinder, the connecting cylinder is fixedly provided at the bottom of the cover plate, external threads are provided on the outer wall of the connecting cylinder, the connecting cylinder is threadedly connected to the inner wall of the upper end of the machine head, the inner diameter of the connecting cylinder is larger than the diameter of the circular plate, and the bottom surface of the cover plate in the area inside the connecting cylinder is an inclined surface.

[0013] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, a plurality of arc-shaped grooves are formed on the circumferential wall of the cover plate.

[0014] In the aforementioned electric dental handpiece with an automatic telescopic function, preferably, the elastic member is a spring.

[0015] Compared with the prior art, the present invention includes a handle and a machine head. The machine head is fixedly connected to one end of the handle. Inside the machine head, a hollow shaft and a bur mounting shaft are provided. The hollow shaft is rotatably mounted inside the machine head. The bur mounting shaft is splined to the hollow shaft. The bur is threadedly connected to the bur mounting shaft. An elastic member is installed inside the hollow shaft. The bur mounting shaft is connected to the bottom surface of the end cap assembly through a connecting member. The end cap assembly is threadedly connected to the top end of the machine head. The bottom surface of the end cap assembly is an inclined surface. In the present invention, the bur mounting shaft is splined to the hollow shaft, enabling the bur mounting shaft to axially move relative to the hollow shaft. Through the cooperation of the connecting member with the inclined surface at the bottom of the end cap assembly and under the action of the elastic member, the bur mounting shaft makes a reciprocating motion. Thus, while the bur rotates, it also makes an axial reciprocating motion, replacing the dentist's point-touch operation. The dentist only needs to hold the handle, reducing physical exertion and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is an isometric view of the present invention;

[0017] Figure 2 is an exploded view of the present invention;

[0018] Figure 3 is a schematic diagram of the internal structure after the machine head and the handle are cut open;

[0019] Figure 4 is a front view of the present invention after partial half-section;

[0020] Figure 5 is a schematic diagram of the structure of the bur mounting shaft, the circular plate and the connecting member;

[0021] Figure 6 is a schematic diagram of the structure of the hollow shaft and the first bevel gear after partial half-section;

[0022] Figure 7 is an isometric view of the end cap assembly.

[0023] DESCRIPTION OF THE REFERENCE NUMERALS: handle 1, machine head 2, hollow shaft 3, bur mounting shaft 4, end cap assembly 5, bur 6, internal spline 7, first bearing 8, second bearing 9, first bevel gear 10, transmission shaft 11, second bevel gear 12, bur guide shaft 13, bur guide hole 14, external spline 15, circular plate 16, connecting column 17, limit cap 18, ball 19, cover plate 20, connecting cylinder 21, arc-shaped groove 22, bur mounting hole 23, annular limit boss 24, spring 25. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0025] Embodiment of the present invention: As Figures 1-7 shown, an electric dental handpiece with an automatic telescopic function includes a handle 1 and a head 2. The head 2 is fixedly connected to one end of the handle 1. A hollow shaft 3 and a bur mounting shaft 4 are arranged in the head 2. The hollow shaft 3 is rotatably mounted in the head 2. The bur mounting shaft 4 is spline-connected to the hollow shaft 3. A bur 6 is threadedly connected to the bur mounting shaft 4. An elastic member is installed in the hollow shaft 3. The bur mounting shaft 4 is connected to the bottom surface of the end cap assembly 5 through a connecting member. The end cap assembly 5 is threadedly connected to the top end of the head 2. The bottom surface of the end cap assembly 5 is an inclined surface.

[0026] By designing the bottom surface of the end cap assembly 5 as an inclined surface, when the connecting member moves on the bottom surface of the end cap assembly 5, an axial displacement will be generated at the same time, so that the bur mounting shaft 4 also generates an axial displacement. Since there is an elastic member at the lower end of the bur mounting shaft 4, the elastic member always provides a thrust to the bur mounting shaft 4. In this way, while the hollow shaft 3 drives the bur mounting shaft 4 to rotate, the bur mounting shaft 4 can also perform reciprocating motion along the axis, replacing the point-touch operation of the human hand, thereby improving work efficiency.

[0027] In a specific embodiment, an annular limiting boss 24 is provided on the inner wall at the lower end of the head 2, and a thread is provided on the inner wall at the upper end of the head 2. The interior of the hollow shaft 3 has a stepped cavity structure that is larger at the top and smaller at the bottom. A plurality of internal splines 7 are provided on the upper inner wall of the hollow shaft 3. The diameter of the lower part of the hollow shaft 3 is slightly larger than the diameter of the bur 6, so that the bur 6 can rotate smoothly without wobbling.

[0028] The purpose of designing the interior of the hollow shaft 3 as a stepped cavity is to make the lower end of the elastic member have a supporting part. In this embodiment, the elastic member is a spring 25. The lower end of the spring 25 abuts against the stepped surface, and the upper end of the spring 25 abuts against the bottom surface of the bur mounting shaft 4. The spring 25 always provides an upward thrust to the bur mounting shaft 4, so that the upper end of the connecting member can always be in contact with the bottom surface of the end cap assembly 5.

[0029] Further, a first bearing 8 is installed on the outer wall at the upper end of the hollow shaft 3, and a second bearing 9 is installed on the outer wall at the lower end of the hollow shaft 3. The inner rings of the first bearing 8 and the second bearing 9 are in interference fit with the hollow shaft 3, that is, the first bearing 8 and the second bearing 9 will not produce axial displacement on the hollow shaft 3. The bottom surface of the outer ring of the second bearing 9 abuts against the annular limiting boss 24, and the annular limiting boss 24 is used to limit the axial position of the second bearing 9. The outer diameters of the first bearing 8 and the second bearing 9 are equal to the inner diameter of the machine head 2; a first bevel gear 10 is also installed on the outer wall of the hollow shaft 3, and the first bevel gear 10 is in interference fit with the hollow shaft 3. A transmission shaft 11 is rotatably installed in the handle 1, and a second bevel gear 12 is provided at the end of the transmission shaft 11. The second bevel gear 12 is also in interference fit with the transmission shaft 11, and the second bevel gear 12 meshes with the first bevel gear 10.

[0030] The internal structure of the handle 1 adopts the prior art. In the figure, only the second bevel gear 12 that needs to cooperate with the first bevel gear 10 and the transmission shaft 11 for installing the second bevel gear 12 are shown. Other structures and components in the handle 1 are not described in detail in this embodiment and are not shown in the figure either. One end of the handle 1 away from the machine head 2 is connected to a drive motor (the drive motor is the prior art and is not shown in the figure). During operation, the drive motor drives the transmission shaft 11 in the handle 1 to rotate. The second bevel gear 12 at the end of the transmission shaft 11 drives the first bevel gear 10 to rotate, and the first bevel gear 10 drives the hollow shaft 3 to rotate. Since the needle mounting shaft 4 is in spline connection with the hollow shaft 3, when the hollow shaft 3 rotates, it will drive the needle mounting shaft 4 to rotate synchronously, so that the needle 6 rotates.

[0031] Further, a needle guide shaft 13 is fixedly provided at the lower end of the hollow shaft 3. A needle guide hole 14 is provided at the center of the needle guide shaft 13. The upper end of the needle guide shaft 13 is a frustum structure with a larger upper part and a smaller lower part, and the lower end of the needle guide shaft 13 is a cylindrical structure.

[0032] The diameter of the needle guide hole 14 is slightly larger than the diameter of the needle 6. The setting of the needle guide shaft 13 can play a role in guiding the needle 6 and prevent the needle 6 from being skewed.

[0033] A plurality of external splines 15 are provided on the outer wall of the needle mounting shaft 4. A circular plate 16 is fixedly provided at the top end of the needle mounting shaft 4. The connecting member is arranged at the edge of the top surface of the circular plate 16. A needle mounting hole 23 is provided on the needle mounting shaft 4. The inner wall of the needle mounting hole 23 has threads, and the upper end of the needle 6 is threadedly connected to the needle mounting hole 23.

[0034] The external splines 15 on the outer wall of the needle mounting shaft 4 cooperate with the internal splines 7 on the inner wall of the hollow shaft 3. In this way, when the hollow shaft 3 rotates, it will drive the needle mounting shaft 4 to rotate synchronously, and at the same time, it does not affect the axial movement of the needle mounting shaft 4.

[0035] The connecting piece includes a connecting column 17, a limiting cap 18 and a ball 19. The lower end of the connecting column 17 is fixedly connected to the top surface of the circular plate 16. A spherical groove is formed at the top end of the connecting column 17. The ball 19 is placed in the spherical groove and is limited by the limiting cap 18. The limiting cap 18 is threadedly connected to the upper end of the connecting column 17. A through hole is provided on the limiting cap 18, and the diameter of the through hole is smaller than the diameter of the ball 19.

[0036] After the limiting cap 18 is tightened with the connecting column 17, the ball 19 can roll smoothly between the connecting column 17 and the limiting cap 18 and will not come off. Using the ball 19 to contact the bottom surface of the end cover assembly 5 can effectively reduce the friction force and improve the service life.

[0037] The end cover assembly 5 includes a cover plate 20 and a connecting cylinder 21. The connecting cylinder 21 is fixedly provided at the bottom of the cover plate 20. The outer wall of the connecting cylinder 21 has a thread, and the connecting cylinder 21 is threadedly connected to the inner wall of the upper end of the machine head 2. The inner diameter of the connecting cylinder 21 is larger than the diameter of the circular plate 16. The area of the bottom surface of the cover plate 20 located inside the connecting cylinder 21 is an inclined surface.

[0038] A plurality of arc-shaped grooves 22 are formed on the circumferential wall of the cover plate 20. The design of the arc-shaped grooves 22 facilitates the disassembly and assembly of the cover plate 20 using tools.

[0039] The working principle of the present invention: When in use, the present invention is connected to a driving motor. When the driving motor works, it drives the transmission shaft 11 to rotate. The second bevel gear 12 at the end of the transmission shaft 11 drives the first bevel gear 10 inside the machine head 2 to rotate. The first bevel gear 10 drives the hollow shaft 3 to rotate. Since the drill bit mounting shaft 4 and the hollow shaft 3 are in spline fit, when the hollow shaft 3 rotates, it drives the drill bit mounting shaft 4 to rotate synchronously. Since the drill bit 6 is threadedly connected to the drill bit mounting hole 23 on the drill bit mounting shaft 4, the drill bit 6 will rotate synchronously with the drill bit mounting shaft 4. While the drill bit mounting shaft 4 is rotating, the circular plate 16 drives the connecting piece to move, and the ball 19 on the connecting piece rolls on the bottom surface of the cover plate 20. Since the bottom surface of the cover plate 20 is an inclined surface, when the ball 19 moves on the bottom surface of the cover plate 20, it will generate an axial movement. Figure 4 The state shown is the maximum position where the drill bit mounting shaft 4 moves upward. When the circular plate 16 rotates 180°, the ball 19 contacts the lowest position of the bottom surface of the cover plate 20. At this time, the drill bit mounting shaft 4 moves downward to the maximum position. As the position of the ball 19 changes, the drill bit mounting shaft 4 rotates and makes an axial reciprocating motion while rotating, enabling the drill bit 6 to have a point contact effect.

[0040] The structure, features and effects of the present invention have been described in detail based on the embodiments shown in the drawings. The above is only the preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the drawings. Any changes made according to the concept of the present invention, or equivalent embodiments modified into equivalent changes, should still be within the protection scope of the present invention when they do not exceed the spirit covered by the specification and the drawings.

Claims

1. An electric dental handpiece with an automatic telescopic function, comprising a handle (1) and a head (2), the head (2) being fixedly connected to one end of the handle (1), characterized in that: A hollow shaft (3) and a bur mounting shaft (4) are arranged in the machine head (2). The hollow shaft (3) is rotatably mounted in the machine head (2). The bur mounting shaft (4) is splined to the hollow shaft (3). A bur (6) is threadedly connected to the bur mounting shaft (4). An elastic member is mounted in the hollow shaft (3). The bur mounting shaft (4) is connected to the bottom surface of the end cap assembly (5) through a connecting member. The end cap assembly (5) is threadedly connected to the top end of the machine head (2). The bottom surface of the end cap assembly (5) is an inclined surface.

2. The electric dental handpiece with an automatic telescopic function according to claim 1, characterized in that: An annular limiting boss (24) is provided on the inner wall at the lower end of the machine head (2), and a thread is provided on the inner wall at the upper end of the machine head (2).

3. The electric dental handpiece with an automatic telescopic function according to claim 2, wherein: The interior of the hollow shaft (3) has a stepped cavity structure with a larger upper part and a smaller lower part. A plurality of internal splines (7) are provided on the inner wall of the upper part of the hollow shaft (3).

4. The electric dental handpiece with an automatic telescopic function according to claim 3, characterized in that: A first bearing (8) is mounted on the outer wall at the upper end of the hollow shaft (3), and a second bearing (9) is mounted on the outer wall at the lower end of the hollow shaft (3). The bottom surface of the outer ring of the second bearing (9) abuts against the annular limiting boss (24). A first bevel gear (10) is further mounted on the outer wall of the hollow shaft (3). A transmission shaft (11) is rotatably mounted in the handle (1). A second bevel gear (12) is provided at the end of the transmission shaft (11). The second bevel gear (12) meshes with the first bevel gear (10).

5. The electric dental handpiece with an automatic telescopic function according to claim 4, characterized in that: A bur guiding shaft (13) is fixedly provided at the lower end of the hollow shaft (3). A bur guiding hole (14) is formed in the center of the bur guiding shaft (13). The upper end of the bur guiding shaft (13) has a frustum structure with a larger upper part and a smaller lower part, and the lower end of the bur guiding shaft (13) has a cylindrical structure.

6. The electric dental handpiece with an automatic telescopic function according to claim 5, characterized in that: A plurality of external splines (15) are provided on the outer wall of the bur mounting shaft (4). A circular plate (16) is fixedly provided at the top end of the bur mounting shaft (4). The connecting member is arranged at the edge of the top surface of the circular plate (16). A bur mounting hole (23) is formed in the bur mounting shaft (4). A thread is provided on the inner wall of the bur mounting hole (23). The upper end of the bur (6) is threadedly connected to the bur mounting hole (23).

7. The electric dental handpiece with an automatic telescopic function according to claim 6, characterized in that: The connecting member includes a connecting column (17), a limiting cap (18) and a ball (19). The lower end of the connecting column (17) is fixedly connected to the top surface of the circular plate (16). A spherical groove is formed at the top end of the connecting column (17). The ball (19) is placed in the spherical groove and limited by the limiting cap (18). The limiting cap (18) is threadedly connected to the upper end of the connecting column (17). A through hole is formed in the limiting cap (18), and the diameter of the through hole is smaller than the diameter of the ball (19).

8. The electric dental handpiece with an automatic telescopic function according to claim 7, characterized in that: The end cap assembly (5) includes a cover plate (20) and a connecting cylinder (21). The connecting cylinder (21) is fixedly provided at the bottom of the cover plate (20). The outer wall of the connecting cylinder (21) has threads, and the connecting cylinder (21) is threadedly connected to the inner wall of the upper end of the machine head (2). The inner diameter of the connecting cylinder (21) is larger than the diameter of the circular plate (16). The area of the bottom surface of the cover plate (20) located inside the connecting cylinder (21) is an inclined surface.

9. The electric dental handpiece with an automatic telescopic function according to claim 8, characterized in that: A plurality of arc-shaped grooves (22) are formed on the circumferential wall of the cover plate (20).

10. The electric dental handpiece with an automatic telescopic function according to claim 1, characterized in that: The elastic member is a spring (25).

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