CN214511261U

CN214511261U - Torsion limiting device and ultrasonic cutting hemostasis system

Info

Publication number: CN214511261U
Application number: CN202023042631.XU
Authority: CN
Inventors: 邵宏泉
Original assignee: Sonoscape Medical Corp
Current assignee: Sonoscape Medical Corp
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2021-10-29
Anticipated expiration: 2030-12-16

Abstract

The utility model provides an ultrasonic cutting hemostasis system and a torsion limiting device thereof, wherein the torsion limiting device comprises a sleeve shaft which is used for being connected with or integrated with a cutter bar component and a rotating head which is sleeved on the sleeve shaft; one of the two is provided with a first tooth, the other one is provided with a first cantilever on the circumferential surface facing the one, the first cantilever extends along the axial direction and forms an avoiding space with the circumferential surface, and the free end of the first cantilever is provided with a second tooth which is engaged with the first tooth in the circumferential direction; when the rotating head drives the cutter bar assembly to rotate relative to the energy converter handle along the screwing-in direction and exceeds the critical torque, the second tooth moves into the avoiding space to slip off the first tooth and interrupt the torque transmission. From this, the utility model discloses can ensure that threaded connection tightness between cutter arbor subassembly and the transducer handle is moderate to, can satisfy various design force value requirements under the radial space size's that need not the increase rotating head the condition, have stronger designability and practicality.

Description

Torsion limiting device and ultrasonic cutting hemostasis system

Technical Field

The utility model belongs to the technical field of medical instrument, in particular to torsion limiting device and ultrasonic cutting hemostasis system.

Background

The ultrasonic cutting hemostasis system comprises a host, an ultrasonic knife, a transducer handle and a pedal. The main machine and the transducer handle are multi-use products, the ultrasonic knife is a disposable product, and part of the ultrasonic knife can be used for multiple times, wherein the number of times of use is not more than 10. The cutter bar component and the transducer handle in the ultrasonic knife are connected through threads, ultrasonic vibration generated by the transducer handle is transmitted to the inner rod of the cutter bar component through the threads, and then is transmitted to the tong head through the inner rod, so that the cutting and blood coagulation functions of the ultrasonic knife are realized.

The threaded connection is a key factor for ensuring the stable operation of the ultrasonic cutting hemostasis system. Too loose a threaded connection can result in unstable vibration transmission, failure of the ultrasonic cutting hemostasis system to vibrate at the desired operating frequency, and failure to achieve the desired working effect. The over-tight connection can accelerate the damage of the thread of the transducer and shorten the service life of the transducer.

Therefore, the problem to be solved by those skilled in the art is how to ensure a moderate tightness of the threaded connection between the knife bar assembly and the transducer handle.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a torsion limiting device and ultrasonic cutting hemostasis system can ensure that threaded connection tightness is moderate between cutter arbor subassembly and the transducer handle.

In order to solve the technical problem, the utility model provides a torsion limiting device which is used for limiting the tightness of the threaded connection between a cutter bar component of an ultrasonic knife and a handle of an energy converter, the torsion limiting device comprises a sleeve shaft and a rotating head, wherein,

the sleeve shaft is used for being connected with the cutter bar assembly, or the sleeve shaft is integrated with the cutter bar assembly;

the rotating head is used for driving the sleeve shaft to rotate around a shaft, and the rotating head is sleeved on the sleeve shaft;

one of the sleeve shaft and the rotating head is provided with a first tooth, the other one of the sleeve shaft and the rotating head is provided with a first cantilever on the peripheral surface facing the one of the sleeve shaft and the rotating head, the first cantilever extends along the axial direction and forms an avoiding space with the peripheral surface, the free end of the first cantilever is provided with a second tooth, and the second tooth and the first tooth are a pair of circumferential meshing teeth;

when the rotating head drives the cutter bar assembly to rotate relative to the energy converter handle along the screwing-in direction and exceeds the critical torque, the second tooth moves into the avoidance space to slip off from the first tooth and interrupt torque transmission;

when the rotating head drives the cutter bar assembly to rotate relatively to the transducer handle along the screwing-out direction, the first tooth and the second tooth are meshed.

Optionally, a contact surface of the first tooth and the second tooth is a tooth surface, and an inclination of the tooth surface in a screwing-in direction is smaller than an inclination of the tooth surface in a screwing-out direction.

Optionally, the cross section of the tooth-shaped surface is asymmetric V-shaped or trapezoidal.

Optionally, the first tooth is a convex tooth, and the second tooth is a concave tooth; or, the first tooth is a concave tooth, and the second tooth is a convex tooth;

the number of the concave teeth is integral multiple of the convex teeth.

Optionally, the torque limiting device further includes an elastic washer, and the elastic washer is disposed in the avoiding space.

Optionally, the sleeve shaft is mounted on the cutter bar assembly through a pin shaft.

Optionally, a protective sleeve is sleeved on the pin shaft.

Optionally, an axial limiting mechanism is further arranged between the rotating head and the sleeve shaft.

Optionally, the axial limiting mechanism includes:

an annular groove disposed on one of the rotary head and the sleeve shaft;

a cantilevered snap disposed on the other of the rotary head and the quill, the cantilevered snap including a second cantilever and a snap disposed at a free end of the second cantilever;

the buckling part is clamped in the annular groove, and the buckling part is in clearance fit with the annular groove.

The utility model also provides an ultrasonic cutting hemostasis system, include:

an ultrasonic blade comprising a blade bar assembly; and the number of the first and second groups,

a transducer handle threadedly connected with the cutter bar assembly;

wherein the ultrasonic blade further comprises:

the torque limiting device as described above, disposed on the knife bar assembly, for limiting the tightness of the threaded connection of the knife bar assembly and the transducer handle.

The utility model provides a torque force limiting device's beneficial effect lies in:

one of a sleeve shaft and a rotating head of the torsion limiting device is provided with a first tooth, the other one of the sleeve shaft and the rotating head faces the circumferential surface of the one of the sleeve shaft and the rotating head is provided with a first cantilever, the first cantilever extends along the axial direction and forms an avoiding space between the circumferential surface and the first cantilever, the free end of the first cantilever is provided with a second tooth, the first tooth and the second tooth are in circumferential meshing transmission in the screwing-in process of driving a cutter bar assembly through the rotating head, torsion applied to the rotating head by an operator is transmitted to an inner rod of the cutter bar assembly by means of tooth surface friction force, and then the end part with internal threads in the inner rod is screwed into a screw rod of a transducer handle, so that the cutter bar assembly and the transducer handle are connected. When the screw thread is screwed to the design force value, the torque force required to be transmitted by the tooth surface is greater than the friction force of the tooth surface, so that the second tooth moves into the avoiding space, the second tooth slides relative to the first tooth, the rotating head slips relative to the sleeve shaft, the screw thread is not screwed any more, and the screw thread connection tightness between the cutter bar assembly and the energy converter handle is moderate. Wherein, because first cantilever extends along the axial, its extension length basically has no influence to the radial space size of rotating head, so, in practical application, can design the extension length (the arm of force) of first cantilever in a flexible way based on arbitrary given design power value to, this torsion limiting device can satisfy various design power value requirements under the condition that need not to increase the radial space size of rotating head (avoid forming the interference between the operation button in rotating head and the operating handle), has stronger designability and practicality.

The utility model provides an ultrasonic cutting hemostasis system has above-mentioned torsion limiting device, consequently, and it has above-mentioned beneficial effect equally, and the repeated description is omitted here.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an ultrasonic cutting hemostasis system provided by an embodiment of the present invention;

fig. 2 is a sectional view of an assembly structure of the cutter bar assembly, the operating handle, the transducer handle and the torque limiting device according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view of the assembled structure shown in FIG. 2 taken along the line A-A, with the associated structure of the knife bar assembly omitted;

fig. 4 is a schematic structural diagram of a sleeve provided in an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a rotary head according to an embodiment of the present invention.

The reference numerals in the above figures include:

a host 100; an ultrasonic blade 200; a knife bar assembly 210; an inner rod 211; a middle sleeve 212; an outer sleeve 213; an operating handle 220; a transducer handle 300; a screw 310; a foot board 400;

a torsion limiting device 500; a sleeve shaft 510; a first tooth 511; a rotating head 520; a second tooth 521; an encapsulating layer 522; an elastic washer 530; a pin 540; a protective sleeve 541; an annular groove 551; a cantilevered snap 552; precessing in; and out of the way.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated with respect to the orientation description, such as up, down, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality is more than two, and if there is a description that the first and the second are only used for distinguishing technical features, it is not understood that the relative importance is indicated or implied or the number of the indicated technical features is implicitly indicated or the precedence of the indicated technical features is implicitly indicated.

In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.

The core of the utility model is to provide a torsion limiting device and ultrasonic cutting hemostasis system can ensure that threaded connection tightness between cutter arbor subassembly and the transducer handle is moderate.

In order to make those skilled in the art better understand the technical solutions provided by the present invention, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Fig. 1 is a schematic structural diagram of an ultrasonic cutting hemostasis system provided by an embodiment of the present invention; specifically, referring to fig. 1, the ultrasonic cutting hemostasis system includes: a host 100, an ultrasonic blade 200, a transducer handle 300, and a foot pedal 400.

Host 100 is communicatively coupled to transducer handle 300 and foot pedal 400, respectively. An operator may input a control signal to the host 100 through the foot pedal 400. Based on the received control signal, the host 100 may generate an excitation signal and transmit the excitation signal to the transducer handle 300 to excite the transducer handle 300 to generate mechanical vibration.

One end of the transducer handle 300 is provided with a screw 310, and the screw 310 is provided with an external thread for connecting with the ultrasonic blade 200.

The ultrasonic blade 200 includes a blade bar assembly 210 and an operating handle 220 for an operator to grasp and input control signals. Specifically, as shown in fig. 2, the knife bar assembly 210 includes an inner rod 211, a middle sleeve 212, and an outer sleeve 213, which are sequentially sleeved from inside to outside, and the three are fixedly connected by a pin 540. The end of the inner rod 211 is provided with an internal threaded hole, which can extend into the operating handle 220 to connect with the external thread on the screw 310 of the transducer handle 300, so as to transmit the mechanical vibration generated by the transducer handle 300 from the proximal end (i.e., the end close to the operator) to the distal end (i.e., the end far away from the operator) to perform ultrasonic cutting and/or hemostasis on the tissue.

In particular, in the present embodiment, the ultrasonic cutting hemostasis system further comprises a torsion limiting device 500 disposed on the knife bar assembly 210 and used for limiting the tightness of the threaded connection of the knife bar assembly 210 and the transducer handle 300.

It should be understood that the core of the present invention lies in the torque limiting device 500, and therefore, the embodiments of the present invention are described in detail with respect to the torque limiting device 500. For other structures in the ultrasonic cutting hemostasis system provided by the embodiment, reference may be made to the related art, and detailed description thereof will not be provided herein.

Specifically, referring to fig. 2 and 3, the torque limiting device 500 may include: a sleeve shaft 510 and a swivel head 520. Wherein:

sleeve shaft 510 is adapted to couple with knife bar assembly 210, or sleeve shaft 510 may be integrated directly with knife bar assembly 210.

That is, in one embodiment, for convenience of production and cost reduction, the sleeve shaft 510 may be a separate component, which is fixedly connected to the knife bar assembly 210 and can drive the knife bar assembly 210 to rotate together. Specifically, sleeve shaft 510 may be mounted to knife bar assembly 210 via pin 540 (i.e., via pin 540, securing inner rod 211, middle sleeve 212, outer sleeve 213, and sleeve shaft 510 together). Further, the pin shaft 540 may be sleeved with a protective sleeve 541, and the protective sleeve 541 may specifically be an elastic member such as a silica gel sleeve, which may play a role in anti-skidding and vibration reduction.

Alternatively, in another embodiment, to reduce the number of parts and space, the related structure of the sleeve shaft 510 may be directly integrated into the knife bar assembly 210, for example, the related structure of the sleeve shaft 510 is formed on the outer sleeve 213 of the knife bar assembly 210. In this embodiment, i.e. using the outer sleeve 213 as the sleeve shaft 510, the modification of all embodiments of the present invention is performed on the outer sleeve 213, and the machining modification is performed on the outer sleeve 213 during the actual production.

The rotating head 520 is sleeved on the sleeve shaft 510 for driving the sleeve shaft 510 to rotate around the shaft, so as to drive the inner rod 211 in the knife bar assembly 210 to rotate. The rotating head 520 and the sleeve shaft 510 may be disposed coaxially with the inner rod 211, and thus, the shaft may be a central axis of the inner rod 211. Further, the holding position of the spin head 520 may be provided with an encapsulating layer 522. The encapsulating layer 522 is made of a softer material, so that the use feeling can be improved.

Specifically, in the present embodiment, the sleeve shaft 510 is provided with a first tooth 511, the rotary head 520 is provided with a first cantilever on a circumferential surface facing the sleeve shaft 510, the first cantilever extends in an axial direction (i.e., the first cantilever is parallel to a central axis of the cutter bar assembly 210) and forms an avoidance space with the circumferential surface, a free end of the first cantilever is provided with a second tooth 521, and the second tooth 521 and the first tooth 511 are a pair of circumferentially engaged teeth;

when the tool bar assembly 210 is driven by the rotary head 520 to rotate relative to the transducer handle 300 in the screwing direction and the critical torque is exceeded, the second tooth 521 moves into the avoidance space to slip off the first tooth 511 and interrupt the torque transmission, so that the torque over-force protection is formed.

When the cutter bar assembly 210 is driven to rotate in the unscrewing direction relative to the transducer handle 300 by the swivel head 520, the first teeth 511 and the second teeth 521 mesh.

It should be noted that the critical torque is a preset value and is set to prevent the threaded screw thread from being damaged due to over-tightening of the knife bar assembly 210 and the transducer handle 300. After the thread specification is determined, the thread tightening torque is obtained with reference to national standards. The design of the tooth pairs is designed according to this torque value, so that the critical torque of the tooth pairs is equal to or slightly greater than this value.

Further, it is understood that, in the present embodiment, the first teeth 511 are provided on the outer circumferential surface of the sleeve shaft 510 (i.e., the circumferential surface facing the rotator head 520), the first cantilevers are provided on the inner circumferential surface of the rotator head 520 (i.e., the circumferential surface facing the sleeve shaft 510), the first cantilevers extend in the axial direction and form an escape space with the inner circumferential surface of the rotator head 520, and the free ends of the first cantilevers are provided with the second teeth 521 only for the convenience of exemplary illustration; in other embodiments, the inner circumferential surface of the rotating head 520 may be provided with first teeth, the outer circumferential surface of the sleeve shaft 510 may be provided with first cantilevers, the first cantilevers extend in the axial direction and form an escape space with the outer circumferential surface of the sleeve shaft 510, and the free ends of the first cantilevers are provided with second teeth.

In a specific embodiment, as shown in fig. 3, the first tooth 511 and the second tooth 521 are in a close fit state under the elastic force of the first cantilever. The contact surface of the first tooth 511 and the second tooth 521 is a tooth surface, and specifically includes a first tooth surface M1 and a second tooth surface M2. The first tooth surface M1 has an angle A1 with the perpendicular bisector, the second tooth surface M2 has an angle A2 with the perpendicular bisector, and the sum of A1 and A2 is the included angle between the two tooth surfaces. Wherein a1 is smaller than a2, the inclination of the first tooth face M1 can be made larger than that of the second tooth face M2. It will be appreciated that the greater the inclination of the tooth faces, the greater the acceptable rotational torque for the tooth pair.

In the present embodiment, the second tooth surface M2 is set to be a tooth surface in the screwing-in direction, and the first tooth surface M1 is set to be a tooth surface in the screwing-out direction, whereby the inclination of the tooth surface in the screwing-in direction is smaller than the inclination of the tooth surface in the screwing-out direction, so that the acceptable rotational torque of the tooth pair in the screwing-in direction is smaller than the acceptable rotational torque thereof in the screwing-out direction.

As the threads are threaded in, second flank M2 is the primary force-bearing surface, relying on flank friction to transmit the torque force applied by the operator on rotary head 520 to the cutter bar assembly 210, thereby connecting the cutter bar assembly 210 to the transducer handle 300. When the torque force required to be transmitted by the second tooth face M2 is larger than the tooth face friction force when the rotating head 520 is screwed to the designed force value, the second tooth 521 is forced to spread outward and move into the avoiding space, so that the rotating head 520 slips relative to the sleeve shaft 510, the thread is not screwed any further, the second tooth 521 passes over the previously engaged first tooth 511 and is engaged with the next adjacent first tooth 511 under the action of the restoring force of the first cantilever, and the in-position prompt sound is given.

After the operation, when the threaded connection between the cutter bar assembly 210 and the transducer handle 300 needs to be loosened, the rotating head 520 is rotated reversely, and the torque transmission surface is the first tooth surface M1, and because the inclination of the tooth surface is larger, larger torque can be transmitted, so the rotating head 520 and the sleeve shaft 510 can be taken as a whole to drive the cutter bar assembly 210 and the transducer handle 300 to loosen the threaded connection.

Further, the cross section of the tooth-shaped surface may be an asymmetric V-shape or a trapezoid. In particular, the V-shaped profile can withstand teeth with low structural strength, and is generally applied to lower critical torque. And the structural strength of the teeth which can be borne by the trapezoidal tooth-shaped surface is higher. Two sides of the V-shaped or trapezoidal tooth-shaped surface are designed into two asymmetric tooth surfaces with different inclinations. Of course, the tooth-shaped surface can be designed into other forms according to actual conditions.

Specifically, in the present embodiment, as shown in fig. 4 and 5, the first teeth 511 are concave teeth, and specifically may be toothed grooves provided on the outer peripheral surface of the sleeve shaft 510; the second tooth 521 is a protruding tooth, and may be a tooth-shaped protrusion protruding from the surface and disposed on the first suspension arm. Of course, in some other embodiments, the first tooth 511 may be a convex tooth, and the second tooth 521 may be a concave tooth, as long as the circumferential engagement between the first tooth 511 and the second tooth 521 can be achieved.

In one case, the number of concave teeth is equal to the number of convex teeth. In another case, the number of concave teeth is an integer multiple of the number of convex teeth. By the arrangement, less convex teeth and more concave teeth can be matched, and the circumferential rotation angle capable of achieving the purpose of limiting torque can be reduced. Preferably, the number of teeth is 3-8.

Further, in order to keep the tooth flanks always in tight fit, the torque limiting device 500 may further include an elastic washer 530, and the elastic washer 530 is disposed in the escape space for providing resiliency to the first cantilever so that the engaging tooth flanks always keep in tight fit.

Here, the rotating head 520 and the sleeve shaft 510 may be formed by injection molding for convenience of production, however, the elastic restoring force provided by the first cantilever of the rotating head 520 formed in this way may not satisfy the design requirement, and the reliability of the torsion limiter 500 may be improved by adding the elastic washer 530. In addition, when the first cantilever has a breakage problem, the elastic washer 530 can keep the broken cantilever at the original position (i.e. the pair of teeth are engaged all the time), and prevent the broken cantilever from scattering in the avoiding space.

The material and hardness of the elastic washer 530 may be selected according to actual conditions, and may be a rubber pad. The elastic washer 530 is an optional element which can be omitted when the structural elasticity of the rotary head itself satisfies a design value.

Further, in order to prevent the second tooth 521 from slipping off one of the first teeth 511 and engaging with the next adjacent first tooth 511 under the restoring force of the first cantilever, an axial position-limiting mechanism may be disposed between the rotary head 520 and the sleeve shaft 510. The axial stop mechanism may axially stop the rotator head 520 and the sleeve shaft 510, but does not limit the rotational freedom of the rotator head 520 relative to the sleeve shaft 510.

Specifically, as shown in fig. 2, 4 and 5, the axial stop mechanism may include an annular groove 551 disposed on the sleeve shaft 510, and a cantilevered catch 552 disposed on the rotary head 520, the cantilevered catch 552 including a second cantilevered arm and a catch disposed at a free end of the second cantilevered arm. The snap fit is configured to snap into the annular groove when the rotator 520 and the sleeve shaft 510 are assembled such that the second tooth 521 mates with the first tooth 511 to axially position the rotator 520 and the sleeve shaft 510. The engagement portion is in clearance fit with the annular groove 551, so that the axial limiting mechanism does not affect the relative rotation between the rotary head 520 and the sleeve shaft 510.

Wherein the second cantilever extends in an axial direction and forms a rebound space with an inner circumferential surface of the rotary head 520. When the rotator 520 and the sleeve shaft 510 are assembled, the engagement portion is outwardly opened by the deformation of the second cantilever and moves into the rebound space. When the buckling part reaches the annular groove, the interference between the two parts is eliminated, the buckling part is buckled into the annular groove under the action of the restoring force of the second cantilever, and at the moment, the second tooth 521 is just butted with the first tooth 511.

In order to facilitate the mold opening and the assembly, the second cantilever may be disposed between two adjacent first cantilevers.

Further, it is understood that in other embodiments, a cantilevered snap may be provided on the sleeve shaft 510 and an annular groove may be provided on the rotator head 520.

Further, in the present embodiment, the operating handle 220 is provided with a fitting groove, which may be a U-shaped groove, and the sleeve 510 is provided with a positioning protrusion for cooperating with the fitting groove. The fitting groove cooperates with the positioning protrusion to limit axial positioning and circumferential rotation of the sleeve shaft 510 on the operating handle 220. The positioning projection and the fitting groove have a play in a circumferential direction such that the sleeve shaft 510 can be circumferentially rotated with respect to the operating handle 220. In addition, the operating handle 220 includes two detachably connected housings, the two housings are respectively provided with a clamping slot and a buckle, and the two housings are buckled and connected.

Thus, when assembling the ultrasonic blade 200, the rotating head 520 may be firstly sleeved on the outer circumference of the sleeve shaft 510 to complete the assembly of the torque limiting device 500; then, fixedly connecting the sleeve shaft 510 with the knife bar assembly 210 through the pin 540, so as to arrange the torsion limiting device 500 on the knife bar assembly 310; subsequently, the positioning protrusion of the sleeve shaft 510 is engaged in a fitting groove of one of the housings of the operating handle 220, and connects the blade lever assembly 210 with other components (e.g., a clamping driving mechanism, etc.) in the operating handle 220; finally, the two housings of the operating handle 220 are snap-coupled, thereby completing the assembly of the ultrasonic blade 200.

From the foregoing, it can be seen that the primary function of rotator head 520 is to provide over-force protection when the knife bar assembly 210 is threadably coupled to the transducer handle 300, but it will be appreciated that it also has a rotation angle function that allows the knife bar assembly 210 to be angled away from the jaws disposed at the distal end of the knife bar assembly 210 during a surgical procedure.

Specifically, in the using process, the first tooth 511 and the second tooth 521 are tightly matched, and the force required for driving the cutter bar assembly 210 and the transducer handle 300 to rotate is small, so that when the rotary head 520 is shifted by a small force, the matched tooth surface between the rotary head 520 and the sleeve shaft 510 cannot slip, and therefore the angle change of the cutter bar assembly 210 and the tong head can be realized by shifting the rotary head 520.

It can be seen from the above embodiment that the utility model provides a torsion limiting device 500 is provided with first tooth 511 in sleeve axle 510 and rotating head 520 one, is provided with first cantilever on another person's global towards one, first cantilever along axial extension and with be formed with between the global and dodge the space, the free end of first cantilever is provided with second tooth 521, in the process of precessing through rotating head 520 drive cutter arbor subassembly 210, first tooth 511 and second tooth 521 mesh the transmission in the circumference, rely on the flank of tooth frictional force to transmit the torsion that operating personnel applyed on rotating head 520 to interior pole 211 of cutter arbor subassembly 210, have the internal screw thread tip screw in on the screw rod 310 of transducer handle 300 in with interior pole 211 to connect cutter arbor subassembly 210 and transducer handle 300. When the thread is screwed to the designed force value, the torque force required to be transmitted by the tooth surface is larger than the friction force of the tooth surface, so that the second tooth 521 moves into the avoidance space, the second tooth 521 slides relative to the first tooth 511, the rotating head 520 slips relative to the sleeve shaft 510, the thread is not screwed any more, and the threaded connection tightness between the cutter bar assembly 210 and the transducer handle 300 is moderate. Wherein, because the first cantilever extends along the axial direction, its extension length basically has no influence to the radial space size of rotating head 520, so, in practical application, can design the extension length (the arm of force) of the first cantilever in a flexible way based on arbitrary given design power value, thereby, this torsion limiting device 500 can satisfy various design power value requirements under the condition that need not to increase the radial space size of rotating head 520 (avoid rotating head 520 and the operation button on operating handle 220 to interfere), have stronger designability and practicality.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The principles and embodiments of the present invention have been explained herein using specific examples, and the above descriptions of the embodiments are only used to help understand the method and its core ideas of the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.

Claims

1. A torque limiting device (500) for limiting the tightness of a threaded connection of a knife bar assembly (210) of an ultrasonic knife (200) and a transducer handle (300), characterized in that the torque limiting device (500) comprises a sleeve shaft (510) and a rotating head (520), wherein,

the sleeve shaft (510) is used for connecting with the cutter bar assembly (210), or the sleeve shaft (510) is integrated with the cutter bar assembly (210);

the rotating head (520) is used for driving the sleeve shaft (510) to rotate around a shaft, and the rotating head (520) is sleeved on the sleeve shaft (510);

one of the sleeve shaft (510) and the rotating head (520) is provided with a first tooth (511), the other one of the sleeve shaft and the rotating head is provided with a first cantilever on the peripheral surface facing the one of the sleeve shaft and the rotating head, the first cantilever extends along the axial direction and forms an avoidance space with the peripheral surface, the free end of the first cantilever is provided with a second tooth (521), and the second tooth (521) and the first tooth (511) are a pair of circumferential meshing teeth;

when the rotating head (520) drives the cutter bar assembly (210) to rotate relative to the transducer handle (300) along a screwing direction and a critical torque is exceeded, the second tooth (521) moves into the avoidance space to slip off the first tooth (511) and interrupt torque transmission;

the first tooth (511) and the second tooth (521) engage when the rotary head (520) drives the cutter bar assembly (210) to rotate relative to the transducer handle (300) in a screw-out direction.

2. The torque limiting device (500) according to claim 1, wherein a contact surface of the first tooth (511) and the second tooth (521) is a toothed surface, and an inclination of the toothed surface in a screwing-in direction is smaller than an inclination of the toothed surface in a screwing-out direction.

3. The torque limiting device (500) according to claim 2, wherein a cross-section of the toothed surface is asymmetric V-shaped or trapezoidal.

4. The torque limiting device (500) according to claim 1, wherein the first teeth (511) are male teeth and the second teeth (521) are female teeth; or, the first tooth (511) is a concave tooth and the second tooth (521) is a convex tooth;

the number of the concave teeth is integral multiple of the convex teeth.

5. The torque limiting device (500) according to claim 1, further comprising a resilient washer (530), wherein the resilient washer (530) is disposed within the relief space.

6. The torque limiting device (500) of claim 1, wherein the sleeve shaft (510) is mounted to the knife bar assembly (210) by a pin (540).

7. The torque limiting device (500) according to claim 6, wherein the pin (540) is sleeved with a protective sleeve (541).

8. The torque limiting device (500) according to any of claims 1 to 7, wherein an axial limiting mechanism is further provided between the rotating head (520) and the sleeve shaft (510).

9. The torque limiting device (500) of claim 8, wherein the axial limiting mechanism comprises:

an annular groove (551) disposed on one of the rotary head (520) and the sleeve shaft (510);

a cantilevered snap (552) disposed on the other of the rotary head (520) and the sleeve shaft (510), the cantilevered snap (552) comprising a second cantilever and a snap disposed at a free end of the second cantilever;

the buckling part is clamped in the annular groove (551), and the buckling part is in clearance fit with the annular groove (551).

10. An ultrasonic cutting hemostasis system, comprising:

an ultrasonic blade (200) comprising a blade bar assembly (210); and the number of the first and second groups,

a transducer handle (300) threadedly coupled with the knife bar assembly (210);

wherein the ultrasonic blade (200) further comprises:

the torque limiting device (500) according to any of claims 1 to 9, arranged on the knife bar assembly (210) for limiting the tightness of the threaded connection of the knife bar assembly (210) and the transducer handle (300).