阅读说明：本技术 一种可切换双刀头的手术电刀 (Operation electrotome with double switchable knife heads ) 是由 陈聪德 吴碎春 林孝坤 夏立广 何国荣 于 2019-08-13 设计创作，主要内容包括：本发明公开了一种可切换双刀头的手术电刀,其在壳体中可滑移的设置对称的两组不同规格的电刀本体,向外伸出手柄进行对电刀本体的操作；两组电刀本体内侧设置导电触点,电源线连接两组导电板,当电刀本体伸出壳体时,导电触点活动至与导电板接触导通电源,当电刀本体收回壳体时,导电触点与导电板分离；壳体中还设置有旋转抵触件,旋转抵触件设置为由一侧电刀本体伸出抵触旋转抵触件旋转时,旋转后的旋转抵触件抵触另一侧的电刀本体令其无法伸出。本发明通过双刀头切换结构的设置,避免原来多组电刀难以管理以及线路缠绕的困扰；通过结构实现收纳在壳体中时刀头不通电,更加安全；通过结构保持一刀头伸出时另一刀头无法伸出,保证安全使用。(The invention discloses a surgical electric knife with switchable double knife heads, wherein two groups of symmetrical electric knife bodies with different specifications are arranged in a shell in a sliding manner, and a handle is extended outwards to operate the electric knife bodies; the inner sides of the two groups of electrotome bodies are provided with conductive contacts, the power line is connected with the two groups of conductive plates, when the electrotome bodies extend out of the shell, the conductive contacts move to be in contact with the conductive plates to conduct the power supply, and when the electrotome bodies are retracted into the shell, the conductive contacts are separated from the conductive plates; still be provided with rotatory conflict piece in the casing, rotatory conflict piece sets up to stretch out the rotatory conflict piece rotation time by one side electrotome body, and rotatory conflict piece after the rotation makes it unable to stretch out by the electrotome body of opposite side. According to the invention, through the arrangement of the double-tool-bit switching structure, the trouble that a plurality of groups of original electric tools are difficult to manage and the lines are wound is avoided; the cutter head is not electrified when being accommodated in the shell through the structure, so that the cutter head is safer; the structure keeps that one cutter head cannot extend out when the other cutter head extends out, so that the safe use is ensured.)

1. The utility model provides a changeable two-bit surgical electric knife, includes casing (1), set up in casing (1) and stretch out electrotome body (2) of use from casing (1) one end to and set up in casing (1) the other end and carry out power cord (3) of electricity connection with electrotome body (2), its characterized in that: the electric knife comprises a shell (1), two groups of electric knife bodies (2) which are arranged in the shell (1) symmetrically and are arranged in different specifications, the two groups of electric knife bodies (2) are arranged in the shell (1) in a sliding manner, handles (21) are arranged outside the side wall of the shell (1) in the two groups of electric knife bodies (2) in the extending manner, the handles (21) are positioned in longitudinal grooves (11) in the side wall of the shell (1) in the sliding manner, and the two groups of electric knife bodies (2) are driven to extend out of or retract into the shell (1); the inner sides of the two groups of electrotome bodies (2) are respectively provided with a conductive contact (22), the power line (3) is connected with two groups of conductive plates (31), when the electrotome bodies (2) extend out of the shell (1), the conductive contacts (22) on the electrotome bodies are moved to be in contact with the conductive plates (31) to conduct a power supply, and when the electrotome bodies (2) are retracted into the shell (1), the conductive contacts (22) are separated from the conductive plates (31); the rotary contact piece (12) is further arranged in the shell (1), and when the rotary contact piece (12) is arranged to extend out of the electric knife body (2) on one side and abut against the rotary contact piece (12) to rotate, the rotary contact piece (12) after rotation abuts against the electric knife body (2) on the other side, so that the rotary contact piece cannot extend out.

2. The electric surgical knife of claim 1 in which: the rotary contact piece (12) is a rod piece with the middle part rotatably arranged in the shell (1), the electric knife bodies (2) are provided with arc-shaped elastic pieces (23) which are in contact fit with the rod piece, and the arc-shaped elastic pieces (23) of the two groups of electric knife bodies (2) are in contact with the rod piece on one side of the electric knife bodies when extending out; when the rod piece is pushed out by the arc-shaped elastic piece (23) on one side in an outward rotating mode, the other side of the rod piece rotates inwards to block the arc-shaped elastic piece (23) on the other side from extending out.

3. The electric surgical knife of claim 2 in which: the inner side and the outer side of the rotary contact piece (12) are respectively provided with a stop block (13) for limiting the rotary limit position of the rotary contact piece (12), and the two stop blocks (13) are located at symmetrical positions and located on the same straight line with the rotary shaft of the arc-shaped elastic piece (23).

4. A switchable double-bladed electrosurgical knife according to claim 2 or 3, characterized in that: the casing (1) comprises an upper casing (14) and a lower casing (15) which are oppositely installed into a whole, a rotating shaft (16) for the rotary contact piece (12) to be rotatably sleeved is arranged in the lower casing (15), and the rotary contact piece (12) can be disassembled and assembled from one open end of the rotating shaft (16); the utility model discloses a rotary electric knife cutting machine, including last casing (14), set up one and rotatory contaction piece (12) position corresponding opening (141) on the epitheca (14), apron (142) are established to opening (141) department detachable lid, conflict pivot (16) open end when apron (142) lid is established and carry out axial spacing to rotatory contaction piece (12), can dismantle rotatory contaction piece (12) from opening (141) department when apron (142) are dismantled, relieve rotatory contaction piece (12) to the spacing of two electrotome bodies (2).

5. A switchable double-bladed electrosurgical knife according to claim 1, 2 or 3, characterized in that: the casing (1) is outside to be provided with annular groove group (4) along axial longitudinal groove (11) corresponding position, still includes snap ring (5), snap ring (5) set up in the position of annular groove group (4) department limit handle (21) through deformation detachable.

6. The electric surgical knife of claim 5 in which: the annular groove group (4) comprises a first annular groove (41) positioned at the retraction limit position of the handle (21) and a plurality of second annular grooves (42) which are continuously arranged in the axial direction and used for limiting the extension length of the electric knife body (2); elasticity snap ring (5) include U-shaped body (51) and set up draw-in groove (52) that be used for both sides handle (21) to go into respectively at U-shaped body (51) both ends, the oral area of U-shaped body (51) is located in first annular (41) or second annular (42) through deformation card, and draw-in groove (52) of both sides restrict the axial activity of handle (21) through blocking handle (21).

7. The electric surgical knife of claim 6 in which: a convex column (53) is arranged in the middle of the inner side of the U-shaped body (51), and a column groove (43) matched with the convex column (53) for limiting is arranged on the inner walls of the first annular groove (41) and the second annular groove (42); the second ring grooves (42) and the corresponding column grooves (43) are arranged at equal intervals.

8. The electric surgical knife of claim 4 in which: the casing (1) is outside to be provided with annular groove group (4) along axial longitudinal groove (11) corresponding position, still includes snap ring (5), snap ring (5) set up in the position of annular groove group (4) department limit handle (21) through deformation detachable.

9. The electric switchable bistrique scalpel according to claim 8, wherein: the annular groove group (4) comprises a first annular groove (41) positioned at the retraction limit position of the handle (21) and a plurality of second annular grooves (42) which are continuously arranged in the axial direction and used for limiting the extension length of the electric knife body (2); elasticity snap ring (5) include U-shaped body (51) and set up draw-in groove (52) that be used for both sides handle (21) to go into respectively at U-shaped body (51) both ends, the oral area of U-shaped body (51) is located in first annular (41) or second annular (42) through deformation card, and draw-in groove (52) of both sides restrict the axial activity of handle (21) through blocking handle (21).

10. The electric switchable bistrique scalpel of claim 9, wherein: a convex column (53) is arranged in the middle of the inner side of the U-shaped body (51), and a column groove (43) matched with the convex column (53) for limiting is arranged on the inner walls of the first annular groove (41) and the second annular groove (42); the second ring grooves (42) and the corresponding column grooves (43) are arranged at equal intervals.

Technical Field

The invention relates to the field of medical instruments, in particular to an electric scalpel capable of switching double knife heads.

Background

The electric knife is a medical instrument for replacing a mechanical scalpel to cut tissues, and the tissue is heated when high-frequency high-voltage current generated by the tip of an effective electrode is contacted with a body, so that the separation and solidification of the body tissue are realized, and the aims of cutting and hemostasis are fulfilled. In the prior art, the electrotome head has multiple styles, namely a wide style and a pointed style which are commonly used, but basically one electrotome head is configured for a single operation electrotome, and a plurality of electrotomes need to be configured when different electrotomes are used, so that the operation environment is easily disordered due to the winding of circuits; if the mode of changing the tool bit is adopted, the tool bit has certain temperature, and the operation is careless after the tool bit is taken down, so that doctors or patients are easily scalded.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the electric scalpel capable of switching the double knife heads, which is not needed to be disassembled and replaced and is safer; can use by two tool bits of a electrotome configuration of adaptability, improve operation efficiency, reduce the operation configuration, make the operation environment more orderly.

The invention adopts the following technical scheme: a surgical electric knife with switchable double knife heads comprises a shell, electric knife bodies and a power line, wherein the electric knife bodies are arranged in the shell, extend out of one end of the shell for use, and are arranged at the other end of the shell and electrically connected with the electric knife bodies; the inner sides of the two groups of electrotome bodies are respectively provided with a conductive contact, the power line is connected with the two groups of conductive plates, when the electrotome bodies extend out of the shell, the conductive contacts on the electrotome bodies move to be in contact with the conductive plates to conduct the power supply, and when the electrotome bodies are retracted into the shell, the conductive contacts are separated from the conductive plates; still be provided with rotatory conflict piece in the casing, rotatory conflict piece sets up to stretch out the rotatory conflict piece rotation time by one side electrotome body, and rotatory conflict piece after the rotation makes it unable to stretch out by the electrotome body of opposite side.

As an improvement, the rotary touch piece is a rod piece with the middle part rotatably arranged in the shell, the electric knife bodies are provided with arc elastic pieces which are matched with the rod piece in a touch way, and the arc elastic pieces of the two groups of electric knife bodies are touched with the rod piece on one side of the electric knife bodies when extending out; when the rod piece is outwards rotated and supported out by the arc-shaped elastic piece at one side, the other side of the rod piece inwards rotates to prevent the arc-shaped elastic piece at the other side from extending out.

As an improvement, the inner side and the outer side of the rotary contact piece are respectively provided with a stop block for limiting the rotary limit position of the rotary contact piece, and the two stop blocks are positioned at the symmetrical positions and positioned on the same straight line with the rotary shaft of the arc-shaped elastic piece.

As an improvement, the shell comprises an upper shell and a lower shell which are oppositely installed into a whole, a rotating shaft for the rotary contact piece to be rotatably sleeved is arranged in the lower shell, and the rotary contact piece can be disassembled and assembled from one open end of the rotating shaft; offer one on the epitheca with rotatory conflict position corresponding opening, the apron is established to opening part detachable lid, and the apron lid is contradicted the open end of pivot and is carried out axial spacing to rotatory conflict piece when establishing, can follow the rotatory conflict piece of opening part dismantlement when the apron is dismantled, relieves the spacing of rotatory conflict piece to two electrotome bodies.

As an improvement, the shell is externally provided with an annular groove group along the axial longitudinal groove corresponding position, and the shell further comprises an elastic snap ring which is detachably arranged at the position of the limiting handle at the annular groove group through deformation.

As an improvement, the annular groove group comprises a first annular groove positioned at the retraction limit position of the handle and a plurality of second annular grooves which are continuously arranged in the axial direction and used for limiting the extension length of the electrotome body; the elastic clamping ring comprises a U-shaped body and clamping grooves which are arranged at two ends of the U-shaped body and used for clamping the handles at two sides respectively, the opening part of the U-shaped body is clamped at the first annular groove or the second annular groove through deformation, and the clamping grooves at two sides limit the axial movement of the handles through clamping the handles.

As an improvement, a convex column is arranged in the middle of the inner side of the U-shaped body, and column grooves matched with the convex column for limiting are arranged on the inner walls of the first annular groove and the second annular groove; a plurality of second ring groove and a plurality of corresponding column groove equidistant setting.

The invention has the beneficial effects that: through the arrangement of the double-cutter head switching structure, a doctor can realize the use requirements of two common cutter heads by using one electrotome, two sets of electrotomes are not required to be prepared, the operation environment is optimized, and the trouble that the original management is difficult and the circuit is wound is avoided; and accomodate the tool bit through the casing and need not to change, the condition that the tool bit lost or injure people takes place when avoiding changing. Through the structure of sliding to conduct the power supply, the cutter head can not be electrified when not used, namely when the cutter head is accommodated in the shell, so that the use is safer; the interference structure keeps one cutter head from extending out while the other cutter head cannot extend out, so that the safety and stability of use are further ensured; the whole structure is simple, the batch manufacturing is convenient, and the device can be better applied to clinical operations.

Drawings

Fig. 1 is a schematic overall perspective view of a first embodiment of the electrosurgical knife of the present invention.

Fig. 2 is a partial longitudinal sectional structural view of a second embodiment of the electrosurgical knife of the present invention.

Fig. 3 is a partial front view of a third embodiment of the electrosurgical knife of the present invention.

Fig. 4 is a partial front perspective structure diagram of a fourth embodiment of the electrosurgical knife of the present invention.

Fig. 5 is a front sectional view of the elastic clasp used in the scalpel of the present invention.

Fig. 6 is a side perspective view of the elastic clasp used in the electric scalpel according to the present invention.

Detailed Description

The following detailed description of specific embodiments of the invention refers to the accompanying drawings.

Fig. 1, 2, 3, 4, 5 and 6 show a specific embodiment of the electric surgical knife with switchable double-bit according to the invention. The electric knife comprises a shell 1, electric knife bodies 2 which are arranged in the shell 1 and extend out of one end of the shell 1 for use, and power lines 3 which are arranged at the other end of the shell 1 and are electrically connected with the electric knife bodies 2, wherein the electric knife bodies 2 are arranged in the shell 1 in two symmetrical groups and are arranged in different specifications, the two groups of electric knife bodies 2 are arranged in the shell 1 in a sliding manner, handles 21 are arranged on the two groups of electric knife bodies 2 in a manner of extending outwards of the side wall of the shell 1, the handles 21 are positioned in longitudinal grooves 11 of the side wall of the shell 1 for sliding, and the two groups of electric knife bodies 2 are driven to extend out; the inner sides of the two groups of electrotome bodies 2 are respectively provided with a conductive contact 22, the power cord 3 is connected with two groups of conductive plates 31, when the electrotome bodies 2 extend out of the shell 1, the conductive contacts 22 on the electrotome bodies move to be in contact with the conductive plates 31 to conduct power supply, and when the electrotome bodies 2 are retracted into the shell 1, the conductive contacts 22 are separated from the conductive plates 31; the casing 1 is further provided with a rotary contact piece 12, and the rotary contact piece 12 is set to extend from one side of the electric knife body 2 to contact with the rotary contact piece 12 to rotate, and the rotary contact piece 12 after rotating contacts with the electric knife body 2 at the other side to prevent the electric knife body from extending.

When the electric knife is used, the circuit can be realized by adopting the prior art, on the basis of the original circuit, a plug is led out from a power line 3 to be connected with an external socket for power supply, two groups of conducting plates 31 are connected and arranged inside the electric knife and are matched with the conducting contacts 22 of the two groups of electric knife bodies 2, and the circuit is conducted when the electric knife bodies 2 extend out of the shell 1 for use; as shown in fig. 2, the current conducting plate 31 is arranged at the side of the sliding direction of the electrotome body 2, and covers a certain length distance, so that the electrotome body 2 can realize the contact conduction of the current conducting contact 22 and the current conducting plate 31 when extending out the shell 1, when the electrotome body 2 extends out different distances, the electrotome body 2 can be flexibly used, the extension length of the electrotome body 2 can be selected by a doctor as required, and the position of the electrotome body 2 can be fixed by the handle 21 through the existing structure to complete the position location of the electrotome body 2. For avoiding stretching out electrically conductively in the electrotome body 2 of both sides, further set up rotatory conflict 12, after one side electrotome body 2 stretches out, conflict rotatory conflict 12 one side screw-out, the inside precession of opposite side, the electrotome body 2 of the opposite side of can be good of contradicting, make it blocked and can't stretch out. Therefore, by the arrangement of the double-cutter head switching structure, a doctor can realize the use requirements of two common cutter heads by one electrotome, two sets of electrotomes do not need to be prepared, the operation environment is optimized, and the trouble that the original operation is difficult to manage and the circuit is wound is avoided; and accomodate electrotome body 2 through casing 1 and need not to change, the condition that the tool bit lost or injure the people when avoiding changing takes place. The structure that the power supply is conducted in a sliding mode is realized through the specific conductive contact 22 and the conductive plate 31, so that the electrotome body 2 cannot be electrified when not used, namely when being accommodated in a shell, and the use is safer; the interference structure of the rotary contact piece 12 keeps one electrotome body 2 from extending out when the other electrotome body 2 extends out, so that the safety and stability of use are further ensured; the whole structure is simple, the batch manufacturing is convenient, and the device can be better applied to clinical operations.

As an improved specific embodiment, the rotary contact element 12 is a rod element whose middle part can be rotatably arranged in the shell 1, the electric knife bodies 2 are provided with arc-shaped elastic elements 23 which are in interference fit with the rod element, and the arc-shaped elastic elements 23 of the two groups of electric knife bodies 2 are in interference fit with the rod element on one side of the electric knife body when extending out; when the arc-shaped elastic piece 23 on one side rotates the rod outwards, the arc-shaped elastic piece 23 on the other side rotates inwards to stop the rod from extending outwards.

As shown in fig. 2 and 4, the electric knife body 2 is specifically provided with an arc-shaped elastic part 23 which is in interference fit with the rod part, so as to ensure the softness of interference between the parts, the arc-shaped elastic part 23 can be preferably a non-conductive elastic plastic part, is mounted on the inner side of the structure of the electric knife body 2 through a fastener, protrudes inwards to be in interference with the rod part, and the electric knife body 2 and the rod part are not in interference structurally; the arc-shaped elastic piece 23 faces the rod piece, and is abutted against the rod piece by virtue of the arc shape, so that the abutted state can be well kept when the rod piece rotates, and the abrasion is small; the member has the ascending displacement of certain width direction after rotatory swing, and the arc of arc elastic component 23 can adapt to the change on the width, good conflict member, member one side by back of screwing out, and the opposite side precession is spacing with the arc elastic component 23 of opposite side to simple structure has realized the alternative use of two electric knife bodies 2, low in manufacturing cost is favorable to medical industry's using widely.

As a modified embodiment, the inner side and the outer side of the rotary contact member 12 are provided with stoppers 13 for limiting the rotation limit position of the rotary contact member 12, and the two stoppers 13 are located at symmetrical positions and are aligned with the rotation axis of the arc-shaped elastic member 23.

As shown in fig. 2 and 4, in order to prevent the rotary contact element 12 from excessively influencing the use, two sets of inner and outer stoppers 13 are further optimally arranged, the arc-shaped elastic element 23 abuts against the stoppers 13 after extending out and abutting against the rotary contact element 12, so that the position of the arc-shaped elastic element is stable (as the position state of fig. 4), the arc-shaped elastic element 23 can continue to extend out along with the electric knife body 2, and is pressed on the rotary contact element 12 through the elastic deformation of the arc-shaped elastic element 23, so that the arc-shaped elastic element is stable in limiting, and is applied to the rotary contact element 12 with a larger resistance, so that the electric knife body 2 on the other side is blocked from moving outwards together with the arc-shaped elastic element 23, the limiting effect is better, and a user is difficult to drive the blocked.

As a modified specific embodiment, the housing 1 includes an upper shell 14 and a lower shell 15 which are oppositely installed as a whole, a rotating shaft 16 for the rotary contact piece 12 to be rotatably sleeved is arranged in the lower shell 15, and the rotary contact piece 12 can be detached from one open end of the rotating shaft 16; the upper shell 14 is provided with an opening 141 corresponding to the position of the rotary contact element 12, the opening 141 is detachably covered with a cover plate 142, the cover plate 142 is abutted against the open end of the rotating shaft 16 to axially limit the rotary contact element 12 when covering, when the cover plate 142 is detached, the rotary contact element 12 can be detached from the opening 141, and the limit of the rotary contact element 12 on the two electric knife bodies 2 is released.

As shown in fig. 4, as a further optimization of the structure, the rotary contact 12 is configured as a structure convenient for disassembly, the housing 1 of the scalpel is designed as a structure of an upper shell 14 and a lower shell 15, and is clamped by an edge clamping structure or fixedly installed by a fastener, and other parts can be separated by the upper shell 14 and the lower shell 15 and then installed in an inner cavity in a centralized manner; if the electrotome body 2 needs to be cleaned, the whole disassembly is not convenient enough. The design of rotatory piece 12 of supporting of windowing dismantlement alone more than adopting, when needs wash two sets of electrotome bodies 2, dismantle the apron 142 of opening 141 department, it is spacing to relieve the axial of rotatory piece 12 of supporting, can take out rotatory piece 12 of supporting, relieve the spacing to both sides arc elastic component 23, then just can stretch out casing 1 simultaneously to both sides electrotome body 2, supply the simultaneous cleaning and disinfection, and efficiency is improved, needn't wholly dismantle casing 1, or spend the twice time to stretch out electrotome body 2 of both sides respectively and carry out cleaning and disinfection. After cleaning and disinfection, the rotary contact piece 12 is installed back again and the cover plate 142 is installed back by reverse operation, which is convenient for quick maintenance of the electric scalpel.

As a modified specific embodiment, the outer part of the shell 1 is provided with an annular groove group 4 along the position corresponding to the axial longitudinal groove 11, and the shell further comprises an elastic snap ring 5, wherein the elastic snap ring 5 is detachably arranged at the position of the limit handle 21 at the annular groove group 4 through deformation. The annular groove group 4 comprises a first annular groove 41 positioned at the retraction limit position of the handle 21 and a plurality of second annular grooves 42 which are continuously arranged in the axial direction and used for limiting the extending length of the electrotome body 2; the elastic clamping ring 5 comprises a U-shaped body 51 and clamping grooves 52 which are arranged at two ends of the U-shaped body 51 and used for clamping the handles 21 at two sides respectively, the opening part of the U-shaped body 51 is clamped at the first annular groove 41 or the second annular groove 42 through deformation, and the clamping grooves 52 at two sides limit the axial movement of the handles 21 by clamping the handles 21.

As shown in fig. 3, 5 and 6, on the basis that the electric knife body 2 is provided with the handle 21, an optimized limit structure is further arranged to realize the positioning of the extending length of the electric knife body 2; when the electric knife is not used, the electric knife bodies 2 on the two sides are retracted to the extreme position, the first annular groove 41 is correspondingly arranged at the position, the elastic snap ring 5 is clamped into the first annular groove 41 by expanding the opening of the U-shaped body 51 according to the deformation of the U-shaped body 51, and the U-shaped body 51 is restored to deform after being clamped in place to realize firm clamping; the clamping grooves 52 on the two sides are clamped to the handle 21, so that the handle 21 cannot move along the longitudinal groove 11, and locking and limiting are realized; when the electric knife body 2 on one side extends out for use, the elastic snap ring 5 arranged at the first ring groove 41 can only be clamped on the handle 21 of the electric knife body 2 on the other side for locking. Handle 21 of the electrotome body 2 that stretches out and use need stop when the length position of needs, and it is relative with the second annular 42 that corresponds the position, then install snap ring 5, can stretch out electrotome body 2 to the required length position of doctor, and the doctor of being convenient for uses the operation electrotome under different custom or under the operating environment, improves use comfort to its location is firm, and the debugging is convenient, is convenient for make processing, and the cost is controlled.

As a modified specific implementation manner, a convex column 53 is arranged in the middle of the inner side of the U-shaped body 51, and a column groove 43 matched with the convex column 53 for limiting is arranged on the inner walls of the first annular groove 41 and the second annular groove 42; the second ring grooves 42 and the corresponding column grooves 43 are arranged at equal intervals.

As shown in fig. 3, 5 and 6, in order to ensure the stable position of the elastic snap ring 5, the use hand feeling of the doctor or the positioning of the handle 21 is not influenced by the rotation; a middle convex column 53 is further arranged to be inserted and matched with the column grooves 43 on the first ring groove 41 and the second ring groove 42; the elastic clamping ring 5 needs to be installed in an accurate direction, and the clamping groove 52 cannot rotate relative to the handle 21 after the elastic clamping ring is installed in place, so that the limiting stability is improved. On the other hand the setting of second ring groove 42 department post groove 43 further provides the reference for the doctor selects the length that electrotome body 2 stretches out, can further set up the reading as the optimization at post groove 43 periphery, for example mark number serial number indicates the centimetre that stretches out, makes the doctor directly select the centimetre that stretches out that oneself is suitable as required, slides handle 21 to corresponding second ring groove 42 and post groove 43 department, uses after installing snap ring 5, more convenience.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.