ZERO-SUCKBACK DEVICE FOR DISPOSABLE HIGH-SPEED TURBINE DENTAL DRILL HANDPIECE

Abstract

A zero-suckback device for a disposable high-speed turbine dental drill handpiece includes two units respectively installed at two ends of the head of the handpiece. On one side of the handpiece head where a drill pin is installed, one unit consists of an elastic shaft sealing casing which is centrally embedded with a central framework made of hard substances and a non-elastic shaft sealing casing, and a lip portion of the elastic shaft sealing casing fits a wind wheel shaft with a tapered end. On the cover side of the handpiece head and between a button housing and a head housing, an O-shaped sealing ring is installed, and a one-way ball valve is installed at the center of the button housing. Suckback prevention measures are adopted at both sides of the handpiece head, so matters sucked back can be controlled to be a very low level, nearly zero.

Claims

1. A zero-suckback device for a disposable high-speed turbine dental drill handpiece, jointly comprising a suckback prevention device installed on one side of the dental drill handpiece where the handpiece head is equipped with a drill pin and a suckback prevention device installed on one side of the dental drill handpiece where the handpiece head is equipped with a head housing, wherein the dental drill handpiece comprises a handpiece head, a drill pin, a head cover, a front handle and a rear handle, the head cover comprises a head housing and a button housing; a power wind wheel and a wind wheel shaft which drive the drill pin to rotate are disposed in a space formed by fastening the handpiece head and the head cover; the wind wheel shaft is supported by two bearings; O-shaped rubber damping rings are disposed between the bearings and the handpiece head; the wind wheel shaft is provided with the head cover at the upper end; a neck of the head is provided with a water duct, an air intake passage and an air exhaust passage; an opening of the air intake passage is positioned at the power wind wheel; and wherein: an annular clamping slot is disposed between the head housing and the button housing and positioned on an inner side of the head housing, the clamping slot is internally embedded with an O-shaped sealing ring; the button housing is provided with a one-way air exhaust mechanism; wherein the wind wheel shaft disposed in the handpiece head has one end connected to the drill pin while the end is a conical brake face, a lower end of the wind wheel shaft is retractably disposed in the handpiece head; wherein the handpiece head is equipped with an elastic shaft sealing casing and a non-elastic shaft sealing casing on an end face connected to one side of the drill pin, the elastic shaft sealing casing is centrally formed with a drill pin hole with a size which is a little greater than a size of an outer diameter of the drill pin, an outer edge of the non-elastic shaft sealing casing is in connected with an outer edge of the handpiece head through screw threads, the non-elastic shift sealing cover is centrally formed with a drill pin hole with a size which is a little greater than the size of the outer diameter of the drill pin; wherein a thickness of the elastic shaft sealing casing close to a central portion is greater than a thickness of a ring-shaped portion between the central portion and the edge of the elastic shaft sealing casing, an inner surface of the central portion of the elastic shaft sealing casing is a tapered face matched with a brake surface of the wind wheel shaft; and wherein the elastic shaft sealing casing is disposed in the non-elastic shaft sealing casing, and a shape of the inner wall of the non-elastic shaft sealing casing is matched with the exterior shaft of the elastic shaft sealing casing in the inflated state.

2. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 1, wherein the handpiece head and the head cover are made of metal or rubber plastic materials.

3. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 1, wherein the elastic shaft sealing casing is made of rubber or rubber plastics.

4. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 1, wherein the non-elastic shaft sealing casing is made of metal or hard plastic materials.

5. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 1, wherein the O-shaped sealing ring between the head housing and the button housing is made of rubber, plastic or rubber plastic materials.

6. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 1, wherein the one-way air exhaust mechanism is a one-way ball valve, comprising vent holes which are formed in a center of the button housing and a valve body which is disposed on the button housing, positioned in the dental drill handpiece and corresponds to the vent hole; the valve body contains a valve ball inside; and an exhaust opening is formed at the lower end of the valve body and communicates with an interior of the dental drill handpiece.

7. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 6, wherein a quantity of the vent holes is 2-8.

8. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 7, wherein the quantity of the vent holes is 4.

9. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 6, wherein the valve body is a copper or stainless steel product.

10. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 6, wherein the valve ball is a metal or rubber plastic product.

11. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 1, wherein on one side of the non-elastic shaft sealing casing, the elastic shaft sealing casing is internally embedded with a hard central framework.

12. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 11, wherein the outer diameter of the hard central framework is a little smaller than that of the central portion of the elastic shaft sealing casing, and the size of the inner diameter is a little greater than the size of the outer diameter of the drill pin.

13. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 11, wherein the hard central framework is made of metals, hard rubber plastics or hard plastics.

14. The zero-suckback device for the disposable high-speed turbine dental drill handpiece according to claim 11, wherein the hard central framework is a metal ring.

15. A method of using a zero-suckback device, comprising: providing a high-speed turbine dental drill handpiece comprising: a zero-suckback device for a disposable high-speed turbine dental drill handpiece, jointly comprising a suckback prevention device installed on one side of the dental drill handpiece where the handpiece head is equipped with a drill pin and a suckback prevention device installed on one side of the dental drill handpiece where the handpiece head is equipped with a head housing, wherein the dental drill handpiece comprises a handpiece head, a drill pin, a head cover, a front handle and a rear handle, the head cover comprises a head housing and a button housing; a power wind wheel and a wind wheel shaft which drive the drill pin to rotate are disposed in a space formed by fastening the handpiece head and the head cover; the wind wheel shaft is supported by two bearings; O-shaped rubber damping rings are disposed between the bearings and the handpiece head; the wind wheel shaft is provided with the head cover at the upper end; a neck of the head is provided with a water duct, an air intake passage and an air exhaust passage; an opening of the air intake passage is positioned at the power wind wheel; and wherein: an annular clamping slot is disposed between the head housing and the button housing and positioned on an inner side of the head housing, the clamping slot is internally embedded with an O-shaped sealing ring; the button housing is provided with a one-way air exhaust mechanism; wherein the wind wheel shaft disposed in the handpiece head has one end connected to the drill pin while the end is a conical brake face, a lower end of the wind wheel shaft is retractably disposed in the handpiece head; wherein the handpiece head is equipped with an elastic shaft sealing casing and a non-elastic shaft sealing casing on an end face connected to one side of the drill pin, the elastic shaft sealing casing is centrally formed with a drill pin hole with a size which is a little greater than a size of an outer diameter of the drill pin, an outer edge of the non-elastic shaft sealing casing is in connected with an outer edge of the handpiece head through screw threads, the non-elastic shift sealing cover is centrally formed with a drill pin hole with a size which is a little greater than the size of the outer diameter of the drill pin; wherein a thickness of the elastic shaft sealing casing close to a central portion is greater than a thickness of a ring-shaped portion between the central portion and the edge of the elastic shaft sealing casing, an inner surface of the central portion of the elastic shaft sealing casing is a tapered face matched with a brake surface of the wind wheel shaft; and wherein the elastic shaft sealing casing is disposed in the non-elastic shaft sealing casing, and a shape of the inner wall of the non-elastic shaft sealing casing is matched with the exterior shaft of the elastic shaft sealing casing in the inflated state; and using the zero-suckback device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1 is a structural view of a high-speed turbine dental drill handpiece;

[0050] FIG. 2 is an assembling drawing of the head of the handpiece in the prior art in the working state (when the wind wheel chamber is in the positive pressure state, the two ends of the head exhausts air at two ends without suckback);

[0051] FIG. 3 is an assembling drawing of the head of the handpiece in the prior in the state when the wind wheel rotates by inertia after the air supply is stopped and generates a negative pressure (when the wind wheel chamber is in the negative pressure state, the two ends of the head supplies airflow to the wind wheel chamber, generating the phenomenon of sucking the contaminants back);

[0052] FIG. 4 is a state diagram in which suckback is prevented by the patent ZL 200610200741.X;

[0053] FIG. 5 is a drawing of the handpiece which is only equipped with the suckback prevention device on one side where a drill pin is installed;

[0054] FIG. 6 is a negative pressure diagram of the handpiece which is equipped with the suckback prevention device only on one side when the handpiece stops rotating;

[0055] FIG. 7 is a working state diagram of the handpiece of the disclosure herein; 7a is an overall working state diagram; FIG. 7b is an amplified view of position A in FIG. 7a (the wind wheel chamber is in the positive pressure state, the handpiece head exhausts air from the two ends without suckback);

[0056] FIG. 8 is a state diagram of the handpiece of the disclosure herein when the wind wheel rotates by inertia after the air supply is stopped and generates a negative pressure without suckback; FIG. 8a is an overall state diagram; FIG. 8b is an amplified view of the head housing; FIG. 8c is a top view of the button housing; FIG. 8d is an amplified view of vent holes of the button housing; FIG. 8e is a state diagram of the suckback prevention of the ball valve;

[0057] FIG. 9 is a diagram of the semi-immersion test of one side of the handpiece equipped with the drill pin (the arrow portion is the inlet air pressure indicator);

[0058] FIG. 10 is a diagram of the full water immersion test of the handpiece equipped with the drill pin (the arrow portion is the inlet air pressure indicator);

REFERENCE LABELS

[0059] 1-Handpiece head; 2-head cover; 3-drill pin; 4-front handle; 5-rear handle; 6-non-elastic shaft sealing casing; 7-elastic shaft sealing casing; 8-hard central framework; 9-tapered end face of the wind wheel shaft; 10-bearing; 11-O-shaped rubber damping ring; 12-wind wheel; 13-wind wheel chamber; 14-O-shaped sealing ring; 15-button housing; 16-valve exhaust opening; 17-vent hole; 18-valve ball; 19-valve body; 20-wind wheel shaft

DETAILED DESCRIPTION

Embodiment 1

[0060] Refer to FIG. 1 and FIG. 8. The zero-suckback device for a disposable high-speed turbine dental drill handpiece comprises or consists of a handpiece head 1, a head cover 2, a drill pin 3, a front handle 4 and a rear handle 5. The zero-suckback device of the disclosure herein is installed at two ends of the handpiece head 1.

[0061] 1) On the side where the drill pin 3 is installed, the tapered end face 9 of the wind wheel shaft is manufactured to be conical and fits the lip portion of the elastic shaft sealing casing 7 which is internally embedded with the hard central framework 8, and the opposite face of the other side of the elastic shaft sealing casing 7 is equipped with a non-elastic shaft sealing casing 6 which is installed on the handpiece head 1, preventing the elastic shaft sealing casing 7 from transitional deformation during positive pressure blowing. Meanwhile, the hard central framework 8 in the center of the elastic shaft sealing casing 7 drives the central portion of the elastic shaft sealing casing 7 to move parallel to the central line of the wind wheel shaft 20 during blowing to prevent the narrowing of the compressed air passage during the deformation of the lip portion of the elastic shaft sealing casing 7, thus reducing the rotation speed and the output power losses. The lip portion (namely the center of the elastic shaft sealing casing close to the edge of the drill pin) of elastic shaft sealing casing 6 of the device presses against the tapered end face 9 of the wind wheel shaft by the joint effect of the elastic resetting of the elastic shaft sealing casing 6 and the negative pressure in the wind wheel chamber 13, so the wind wheel 12 brakes and seals up the tapered end face 9 of the wind wheel shaft, preventing the sucked substances from flowing into the wind wheel chamber 13.

[0062] 2) On the side where the handpiece head 1 is equipped with the head cover, the following changes are made and present.

[0063] a) An O-shaped sealing ring 14 is installed between the button housing 15 and the head housing 2, and on the inner side of the head cover, the head housing 2 is formed with an annular slot for embedding the O-shaped sealing ring to prevent contaminants from entering the handpiece when the wind wheel chamber 13 is in negative pressure state.

[0064] b) A one-way valve with a valve ball 18 is installed in the center of the button housing 15 to play the following role: when the wind wheel 12 is rotating and the wind wheel chamber 13 is in positive pressure state, the one-way valve exhausts air for cooling a bearing 10 via vent holes 17. When the wind wheel 12 rotates by inertia after the air supply to the wind wheel 12 is stopped, the valve ball 18 is sucked to reset by the negative pressure in the wind wheel chamber 13, blocking the exhaust opening 16 of the valve body to prevent contaminants from entering the handpiece head 1.

[0065] The handpiece head 1 and the head cover are made of rubber plastic or metal materials.

[0066] The elastic shaft sealing casing 7 is a rubber or rubber plastic product.

[0067] The elastic shaft sealing casing 7 is internally embedded with the hard central framework 8 which is made of metal, hard rubber plastic or hard plastic materials.

[0068] The non-elastic shaft sealing casing 6 outside the elastic shaft sealing casing 7 is made of metal or hard plastics.

[0069] The O-shaped sealing ring 14 between the button housing 15 and the head housing 2 is a rubber or rubber plastic product.

[0070] The quantity of the vent holes 17 of the button housing 15 of the one-way valve is 2-8, preferably 4. The quantity and size of the vent hole are related to the designed exhaust area of the wind wheel.

[0071] The valve body 19 installed in the center of the button housing 15 is a metal or rubber plastic product, and the valve ball 18 in the center is a metal or rubber plastic product, preferably stainless steel ball which is hardened by quenching to increase the wear resistance.

Embodiment 2

[0072] Below is the use method of the high-speed turbine dental drill handpiece equipped with the zero-suckback device of the disclosure herein.

[0073] The use method and operation method of the disposable high-speed turbine dental drill handpiece equipped with the zero-suckback device of the disclosure herein are not different from those of other turbine dental drill handpieces.

[0074] 1) Due to the O-shaped sealing ring 14 installed between the button housing 15 and the head housing 2, the button housing is slightly lowly raised when the doctor installs or removes the drill pin, but at last, can be completely raised to be reset. When the button housing is pressed down, the force applied is completely the same as the force applied to other handpieces, and users may feel gentle and have a better hand feel.

[0075] 2) The handpiece equipped with the zero-suckback device can be quickly braked when the air supply is stopped, thus preventing the occurrence of suckback, and the doctor will feel more safer, convenient and reliable.

[0076] 3) Due to almost zero sucked substance, contaminants are completely prevented from entering the handpiece head and the pipeline, thus effectively preventing cross infection.

Embodiment 3

[0077] Instructions of the water immersion test of the handpiece can be seen in FIG. 9 and FIG. 10.

[0078] The water immersion test of the handpiece is a reliable and convenient method for testing the suckback prevention device of the handpiece.

[0079] 1) Semi-immersion test: see FIG. 9. Take out the handpiece from the therapeutic connector, weigh the handpiece using a balance with a relatively high accuracy, record the weight of the handpiece at this time, re-install the handpiece in the therapeutic machine, close the water spray pipe, pedal the foot-switch to drive the handpiece to rotate normally, immerse the side of the handpiece where the handpiece is equipped with the drill pin into water in a water cup until the water level reaches the half of the handpiece head (the head cover may not be immersed in water), and stop the handpiece from rotating in water. After the handpiece stops, take the handpiece out of the water, remove the handpiece from the therapeutic machine, wipe off the water beads on the surface of the handpiece, and weigh it with the balance again. The weight added on the basis of the weight when the handpiece is not immersed is the suckback quantity of the handpiece after the handpiece is half immersed in water.

[0080] 2) Full water immersion test: see FIG. 10.

[0081] Such test is identical with the semi-immersion test. But, the handpiece should be completely immersed in water after rotating and stops rotating in water. Then, take out the handpiece, weigh the handpiece, and compare the result with the weight of the handpiece before water immersion. The increase is the suckback quantity.

[0082] The handpiece of the disclosure herein can control the suckback quantity to zero or to a very tinny level in the full water immersion test or the semi-immersion test.

[0083] Therefore, such handpiece is called zero-suckback handpiece.