CN110051409B

CN110051409B - Head assembly and surgical instrument

Info

Publication number: CN110051409B
Application number: CN201910400355.2A
Authority: CN
Inventors: 朱莫恕
Original assignee: 5r Med Technology Chengdu Co ltd
Current assignee: 5r Med Technology Chengdu Co ltd
Priority date: 2019-05-15
Filing date: 2019-05-15
Publication date: 2024-05-03
Anticipated expiration: 2039-05-15
Also published as: CN110051409A

Abstract

The invention discloses a head assembly and a surgical instrument, which comprise a base, a first jaw and a second jaw which are matched with each other, wherein the first jaw comprises a first jaw tail, and the second jaw comprises a second jaw tail; the base comprises a shaft shoulder, a first fixing arm and a second fixing arm, wherein the first fixing arm and the second fixing arm extend to the far end, the shaft hole penetrates through the shaft shoulder, the movement base surface and the buckling surface are approximately perpendicularly intersected, and the intersection line of the movement base surface and the buckling surface is basically coincident with a first central shaft of the shaft hole; the first jaw tail and the second jaw tail are clamped between the first fixed arm and the second fixed arm, the first jaw tail and the first fixed arm form a first revolute pair, and the second jaw tail and the second fixed arm form a second revolute pair.

Description

Head assembly and surgical instrument

Technical Field

The invention relates to a minimally invasive surgical instrument, in particular to a endoscopic handheld instrument.

Background

Endoscopic surgery (including hard-lumen endoscopes, fiber endoscopes), i.e., the use of elongated endoscopic hand-held instruments, into a patient's body via a natural lumen or a constructed puncture channel, to complete tissue grasping, shearing, separation, coagulation, suture closure, etc. The main advantages over traditional open surgery are reduced trauma and pain and accelerated recovery. In endoscopic surgery, a doctor can only access internal organs of a patient by means of instruments, and cannot directly feel the internal organs by hands; in addition, the field of view of the laparoscopic surgeon is severely limited and only a localized area of the working head of the instrument can be observed in real time by means of an endoscope and imaging system. Because of limited field of view and lack of tactile feedback in surgical medicine, high requirements are placed on the accuracy, consistency, operability and the like of endoscopic hand-held instruments (endoscopic scissors, endoscopic graspers, endoscopic separation forceps and the like).

To date, reusable endoscopic hand-held instruments (abbreviated as reusable instruments) have been dominant in the market, and disposable endoscopic hand-held instruments (abbreviated as disposable instruments) have relatively few clinical applications. However, many medical documents have deeply parsed the multiplexing apparatus to have problems, a doctor paper named Safety Evaluation of Surgical Instruments,a thesis submitted for the degree of Philosophy doctor(PHD)of University of Dundee,February 2017 has summarized in detail the unreliable and uncontrollable problems of cleaning, distribution and use of the multiplexing apparatus, such as the ion in human blood is very easy to corrode the stainless steel multiplexing apparatus, and no reliable solution has been found so far.

Disposable instruments can effectively solve many problems of multiplexing instruments, however, the cost of a good quality disposable instrument is too high. A research paper, named Reducing the Cost of Laparoscopy:Reusable versus Disposable Laparoscopic Instruments,Minimally Invasive Surgery,Volume 2014, has shown that the cost of application of disposable devices is about 10 times that of reusable devices. The expensive disposable instruments burden the patient and severely hamper the development of laparoscopic surgery. The cost of the apparatus mainly comprises the manufacturing cost of parts, the assembly cost, the sterilization cost, the storage and transportation cost and the like. On the premise of ensuring and even optimizing the functional performance, the cost is very difficult to reduce. One of the most difficult challenges is how to improve the head structure of the instrument. Heretofore, current endoscopic instruments have largely used pin riveting to form the revolute joint. The rivet fixing of the joint pin must be very fine: firstly, the rigidity and hardness of the pin are enough, secondly, the riveting is firm to prevent the pin from falling off, thirdly, the clearance between the pin and the matching hole is reasonable, and the pin can rotate smoothly. Riveting of the joint pin typically requires multiple manual repairs by experienced advanced technicians and multiple verification and validation, which greatly increases the manufacturing cost of the instrument. The single-use endoscopic handheld instrument with performance approaching to, equivalent to or even exceeding that of the multiplexing instrument is optimally designed and manufactured, and meanwhile, the overall cost is obviously reduced, so that the single-use endoscopic handheld instrument is very difficult but has great significance.

Disclosure of Invention

Therefore, in order to solve the problems of the prior art, an instrument assembly capable of effectively reducing the manufacturing cost is proposed.

In one aspect of the invention, a head assembly for minimally invasive surgery includes a base and first and second jaws that cooperate with each other; the first jaw comprises a first jaw tail, a first jaw wrist connected with the first jaw tail and a first jaw head extending to a distal end; the second jaw includes a second jaw tail and a second jaw wrist connected thereto and a second jaw head extending to a distal end. The base comprises a shaft shoulder, a first fixing arm and a second fixing arm, wherein the first fixing arm and the second fixing arm extend to the far end, the shaft hole penetrates through the shaft shoulder, the movement base surface and the buckling surface are approximately perpendicularly intersected, and the intersection line of the movement base surface and the first central shaft of the shaft hole is basically coincident. The first jaw tail and the second jaw tail are clamped between the first fixed arm and the second fixed arm, the first jaw tail and the first fixed arm form a first revolute pair, and the second jaw tail and the second fixed arm form a second revolute pair.

In one embodiment, the first and second tangs are sandwiched between a first fixed arm and a second fixed arm, wherein the first tangs and the first fixed arm form a first under-constrained revolute pair and the second tangs and the second fixed arm form a second under-constrained revolute pair. In a specific embodiment, the first under-constrained revolute pair comprises a first outer cylindrical surface and a first inner cylindrical surface; the first rotation axis of the first underconstrained revolute pair is approximately parallel to the buckling surface and approximately perpendicular to the movement base surface; the first outer cylinder and the first inner cylinder comprise 2 degrees of freedom, namely a rotational degree of freedom about the first rotational axis and a translational degree of freedom along the first rotational axis. Similarly, in a specific scheme, the second under-constrained revolute pair comprises a second outer cylindrical surface and a second inner cylindrical surface; the second rotation axis of the second under-constrained revolute pair is approximately parallel to the buckling surface and approximately perpendicular to the movement base surface; the second outer cylinder and the second inner cylinder comprise 2 degrees of freedom, namely a rotational degree of freedom about the second rotational axis and a translational degree of freedom along the second rotational axis.

In yet another specific scheme, the first jaw tail comprises a first inner cylinder integrally connected with the first jaw tail, the first fixing arm comprises a first outer cylinder integrally connected with the first jaw tail, and the first inner cylinder and the first outer cylinder form a first rotating pair in a free contact mode without additional fixing measures. Similarly, in yet another aspect, the second tail comprises a second inner cylinder integrally connected thereto, the second fixed arm comprises a second outer cylinder integrally connected thereto, and the second inner cylinder and the second outer cylinder form a second revolute pair in free contact without additional fixing means.

In yet another specific aspect, the first tail comprises a first outer cylindrical surface integral therewith, the first fixed arm comprises a first inner cylindrical surface integral therewith, and the first inner cylindrical surface and the first outer cylindrical surface form a first rotating pair in free contact without additional fixing measures. Similarly, in yet another aspect, the second tail comprises a second outer cylindrical surface integral therewith, the second fixed arm comprises a second inner cylindrical surface integral therewith, and the second inner cylindrical surface and the second outer cylindrical surface form a second revolute pair in free contact without additional fixing means.

In one scheme, the first rotating pair and the second rotating pair do not generate extra parts except the first jaw, the second jaw and the base in the assembling and disassembling processes; the assembly and disassembly of the first jaw, the second jaw and the base do not generate additional parts, so that the manufacturing cost of the parts is reduced, the assembly cost is reduced, and the assembly is more accurate and compact.

In still another preferred embodiment, the first jaw, the second jaw and the base satisfy the following relationship: hf1 < Hw1, hf2 < Hw2. Wherein: hb1 is a distance between the first and second fixed arms; hf1 is the protrusion height of the first boss; hf2 is the protrusion height of the second boss; hw1 is the thickness of the first jawbone; hw2 is the thickness of the second jaw.

In yet another preferred embodiment, the base of the elongate shaft assembly, the first jaw, the second jaw are configured and dimensioned to satisfy the following relationship: hw1+hw2+δ2=hb1; wherein Hw1 is the thickness of the first jawbone; hw2 is the thickness of the second jaw tail; hb1 is a distance between the first and second fixed arms; δ2 is a machining error.

In one aspect of the invention, an instrument head assembly for minimally invasive surgery includes a base, a first jaw, a second jaw, and a drive head. The first jaw comprises a first jaw tail, the second jaw comprises a second jaw tail, the base comprises a shaft shoulder, a first fixing arm and a second fixing arm, the first fixing arm and the second fixing arm extend to the far end, the shaft hole penetrates through the shaft shoulder, the movement base surface and the buckling surface are approximately perpendicularly intersected, and the intersection line of the movement base surface and the first central shaft of the shaft hole is basically coincident. The first jaw tail and the second jaw tail are clamped between the first fixed arm and the second fixed arm, the first jaw tail and the first fixed arm form a first revolute pair, and the second jaw tail and the second fixed arm form a second revolute pair. The drive head is clamped between the first jaw tail and the second jaw tail, the drive head and the first jaw tail form a first cam pair, and the drive head and the second jaw tail form a second cam pair.

In one scheme, the driving head can translate along the central axis direction, so that the first cam pair is driven to generate relative sliding to force the first rotating pair to rotate mutually, the second cam pair is driven to generate relative sliding to force the second rotating pair to rotate mutually, and then the first jaw and the second jaw are driven to open or close in rotation.

In one aspect, the first revolute pair, the second revolute pair, the first cam pair and the second cam pair are repeatedly detachable and repeatedly reloadable. In an alternative, no additional parts except the first jaw, the second jaw and the base are generated during the disassembly and reassembly of the first rotating pair and the second rotating pair; the first cam pair and the second cam pair do not generate extra parts except the first jaw, the second jaw and the driving head in the disassembling and reassembling process.

In one aspect, the drive head includes a drive block and first and second drive lugs extending outwardly of the block; the first jaw tail comprises a first driven groove, and the second jaw tail comprises a second driven groove; the first driving lug is matched with the first driven groove to form a first cam pair, and the second driving lug is matched with the second driven groove to form a second cam pair.

In yet another embodiment, the first driven groove comprises a first driven groove proximal opening, and the head assembly first jaw opening angle A1 has three span values: the limit opening angle Au1 ensures that when A1 is more than or equal to Au1, the first driving lug can be completely separated from the first driven groove; the critical opening angle Ae1 such that when a1=ae1, the first drive lug is aligned with the first driven slot proximal opening; the working opening angle Aw1 is designed so that the first driving lug and the first driven groove always keep in contact when A1 is less than or equal to Aw 1.

In yet another embodiment, the first rotating pair comprises a first outboard pair comprising a first cylindrical surface and a first cutout, and a first inboard pair comprising a first cylindrical portion and a first narrow body feature, the dimensions of which satisfy the relationship: dr1 is more than or equal to Df1 and Br1 is more than or equal to Bf1; wherein: dr1 is the cross-sectional diameter of the first cylindrical surface; br1 is the cross-sectional width of the first notch; df1 is the cross-sectional diameter of the first cylindrical portion; bf1 is the cross-sectional width of the first narrow body feature.

In yet another aspect, the first jaw, the second jaw, the drive head and the base satisfy the following relationship: hj1+hj2+hd1+δ1=h1; wherein Hj1 is the thickness of the first tail; hj2 is the thickness of the second tail; hd1 is the thickness of the drive block; hb1 is a distance between the first and second fixed arms; δ1 is a machining error.

In yet another aspect, the drive head includes a drive block and first and second drive lugs extending outwardly of the block; the first jaw tail comprises a first outer side pair and an annular first driven groove, and the second jaw tail comprises an annular second driven groove; the shortest distance between the geometric centroid of the distal end of the first driven groove and the geometric centroid of the first outer side pair along the buckling surface is Lj1, and the distance between the geometric centroid of the first driving lug and the central shaft is Ld1, wherein Lj1 is more than or equal to Ld1.

In another specific implementation scheme, the opening angle A1 of the first jaw comprises two value intervals, namely a design disassembly opening angle Ac1 and a design working opening angle Aw1, wherein Ac1 is larger than Aw1; when A1 is more than or equal to Ac1, the first inner side pair can be separated from the first outer side pair, and when A1 is less than or equal to Aw1, the first inner side pair and the first outer side pair are always kept in contact.

In yet another aspect of the invention, an elongate shaft assembly for minimally invasive surgery is provided, the shaft assembly comprising the foregoing head assembly, a hollow tube coupled to a base, and a drive rod coupled to a drive head. The hollow tube may be rigid or flexible and the drive rod may be rigid or flexible. In one implementation, the shoulder of the base includes a retaining wall extending to a proximal end, and the distal end of the hollow tube is deformed by shrinkage and is wrapped around the outer surface of the retaining wall. In one implementation, the drive head and drive rod are connected with a removable snap fitting, and the snap fitting is restrained within the shaft bore to prevent the snap fitting from falling out.

In yet another aspect of the invention, an instrument product for minimally invasive surgery is presented, the instrument product comprising the foregoing elongate shaft assembly, and further comprising a handle assembly coupled to the elongate shaft assembly. The handle assembly comprises a first handle, a second handle and a handle rotating shaft, wherein the first handle is connected with the hollow tube, the second handle is connected with the driving rod, the first handle and the second handle can rotate around the handle rotating shaft so as to drive the driving head to do translational motion along the central shaft direction, further drive the first cam pair to generate relative sliding so as to force the first rotating pair to rotate mutually, and drive the second cam pair to generate relative sliding so as to force the second rotating pair to rotate mutually, so that the first jaw and the second jaw are rotated to open or close mutually.

Drawings

For a fuller understanding of the nature of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic side view of a base 30;

fig. 2 is a perspective view of the base 30 from the distal end to the proximal end;

FIG. 3 is a schematic side view of the drive head 70;

Fig. 4 is a perspective view of the drive head 70 from the distal end to the proximal end;

fig. 5 is a schematic perspective view of the first jaw 10 (second jaw 20);

fig. 6 is a schematic side view of the head assembly 2;

Fig. 7 is an inside projection view of the first jaw 10a (second jaw 20 a);

FIG. 8 is a schematic view of the limit angle state of the head assembly 2 a;

FIG. 9 is a schematic view of the critical angle state of the head assembly 2 a;

FIG. 10 is a side projection view of the base 30 b;

FIG. 11 is a schematic view of the limit angle state of the head assembly 2 b;

FIG. 12 is a schematic view of the working angle state of the head assembly 2 b;

Fig. 13 is an outside projection view of the first jaw 10c (second jaw 20 c);

fig. 14 is a perspective view of the first jaw 10c (second jaw 20 c);

FIG. 15 is a schematic view of an assembly method of the head assembly 2 c;

FIG. 16 is a distal partial schematic view of the head assembly 2 c;

FIG. 17 is a schematic side view of the base 30 d;

FIG. 18 is a cross-sectional view taken along line 18-18 of FIG. 17;

fig. 19 is a perspective view of the first jaw 10d (second jaw 20 d);

FIG. 20 is a distal partial schematic view of the head assembly 2 d;

fig. 21 is a perspective view of the first jaw 10e (second jaw 20 e);

fig. 22 is a reverse perspective view of the first jaw 10e (second jaw 20 e) shown in fig. 21;

FIG. 23 is a schematic view of the limit angle state of the head assembly 2 e;

FIG. 24 is a schematic side view of the base 30 e;

fig. 25 is a schematic side view of the base 30 f;

FIG. 26 is a cross-sectional view taken along line 26-26 of FIG. 25;

Fig. 27 is a perspective view of the head assembly 2 f;

FIG. 28 is a schematic perspective view of the first jaw 10 g;

FIG. 29 is a schematic perspective view of the head assembly 2 g;

FIG. 30 is an inboard projection view of the first jaw 10 h;

FIG. 31 is a schematic side view of the first jaw 10 h;

FIG. 32 is an assembled schematic view of the head assembly 2 f;

FIG. 33 is a schematic illustration of the connection of the base to the hollow tube;

FIG. 34 is a cross-sectional view of 34-34 of FIG. 33;

FIG. 35 is a schematic view of a connection scheme of a drive head to a drive rod;

FIG. 36 is a schematic view of an asymmetric quick snap-in solution for a drive head and drive rod;

FIG. 37 is a schematic illustration of a drive head and drive rod in a riveted connection;

FIG. 38 is a schematic view of a symmetrical quick-snap-fit solution for a drive head and drive rod;

FIG. 39 is a schematic diagram of a T-shaped quick snap-on solution for a drive head and drive rod;

fig. 40 is a schematic side view of the instrument 1;

throughout the drawings, like reference numerals designate identical parts or elements.

Detailed Description

Embodiments of the present invention are disclosed herein, but it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, the disclosure herein is not to be interpreted as limiting, but merely as a basis for the claims and as a basis for teaching one skilled in the art how to employ the invention.

Referring to fig. 1, for convenience of description, the side closer to the operator is defined as the proximal side, and the side farther from the operator is defined as the distal side. In performing laparoscopic surgery, a penetrating cannula assembly (not shown) is typically used to create a surgical path for instruments into and out of the patient's body wall, and various minimally invasive instruments, such as instrument 1, may be inserted into a body cavity through the path created by the cannula assembly. One or more cannula assemblies may be used simultaneously during surgery, and instrument 1 may be configured for one or more simultaneous operations, as desired during surgery.

Example 1:

Fig. 1-6 depict a head assembly 2 of a typical endoscopic hand-held instrument 1. The head assembly 2 comprises a first jaw 10, a second jaw 20, a base 30 and a drive head 70. The first jaw 10 and the second jaw 20 are matched with each other and mounted between the bases 30, and the driving head 70 is matched with the first jaw 10 and the second jaw 20 with each other; and the driving head 70 is installed in the base 30, and the driving head 70 can move in the axial direction and drive the first jaw 10 and the second jaw 20 to perform a mutual rotational opening or closing movement.

Fig. 1-2 depict the structure and composition of the base 30 in detail. The base 30 includes a shoulder 31 and first and second fixed arms 33 and 34 extending to distal ends, the first and second fixed arms forming a mounting space 300 having a pitch Hb 1. The shaft hole 32 extends through the shoulder 31, and the movement base 371 and the engagement surface 372 intersect substantially perpendicularly, with the intersection line substantially coinciding with the first central axis 37 of the shaft hole 32. The distal end of the first fixed arm 33 includes a first boss 331 of height Hf1 extending from the first mounting surface 330 toward the movement base 371; the distal end of the second fixed arm 34 includes a second boss 341 of height Hf2 extending from the second mounting surface 340 toward the movement base 371. The mounting surface 330, the mounting surface 340 and the base surface 371 are substantially parallel. In one aspect, the first boss 331 and the second boss 341 are respectively located at two sides of the fastening surface 372 and are asymmetric; the first boss 331 and the second boss 341 are respectively located on two sides of the base 371 and are asymmetric.

Fig. 3-4 depict the structure and composition of the drive head 70 in detail. The drive head 70 comprises a second central axis 71, a first transverse plane 711 and a first longitudinal plane 712 intersecting substantially perpendicularly, the intersection line of which coincides substantially with the second central axis 71. The first translation surface 74 and the second translation surface 75 are substantially parallel to said transversal plane 711 and define a driving block 73 of thickness Hd 1. The first drive lug 740 extends by a height Hp1 from said translation surface 74 towards the outside of said block 73; the second drive lug 750 extends from the translation surface 75 to a height Hp2 outside the block 73. As shown in fig. 3-4, the first driving lug 740 has a geometric centroid that is spaced from the central axis 71 by Ld1, and the second driving lug 750 has a geometric centroid that is spaced from the central axis 71 by Ld2, and Ld1 and Ld2 may be equal or unequal. In one version, the first and second drive lugs 740, 750 are on either side of the longitudinal plane 712 and are asymmetric; the first and second drive lugs 740, 750 are on either side of the transverse plane 711 and are asymmetric. The first translation surface 74 and the second translation surface 75 extend proximally to intersect the drive neck 72.

Fig. 5 depicts in detail the structure and composition of the first jaw 10 and the second jaw 20. The proximal end of the first jaw 10 comprises a first tail 13 of thickness Hj1 defined by a first lateral side 11 and a first medial side 12. The first base hole 14 is recessed from the first outer side 11 toward the inside of the tail 13, and the first driven groove 15 is recessed from the first inner side 12 toward the inside of the tail 13. The first jaw wrist 16 is integral with the first jaw tail 13 and extends distally to form a first jaw head 19. The proximal end of the second jaw 20 comprises a second tail 23 of thickness Hj2 defined by a second outer side 21 and a second inner side 22. The second base hole 24 is recessed from the second outer side surface 21 toward the inside of the tail 23, and the second driven groove 25 is recessed from the second inner side surface 22 toward the inside of the tail 23. The second wrist 26 is integral with the second tail 23 and extends distally to form a second jaw 29. Those skilled in the art will readily appreciate that the first (second) jaw may be a split clamp, grasper, scissors, etc.

Fig. 6 depicts the composition and assembly relationship of the head assembly 2. The first jaw 10 and the second jaw 20 are mounted in the base 30, wherein a first mounting surface 330 mates with the first outer side 11 and a second mounting surface 340 mates with the second outer side 21. The first boss 331 is matched with the first base hole 14 to form a first rotating pair 100 (not shown in the figure); the second boss 341 is matched with the second base hole 24 to form a second revolute pair 200 (not shown in the figure); the first revolute pair 100 and the second revolute pair 200 are not coaxial. The drive head 70 is mounted into the base 30 with the first central axis 37 and the second central axis 71 aligned; the first translation surface 74 mates with the first inner side 12; the second translation surface 75 matches the second inner side 22; first drive lug 740 mates with first driven slot 15 to form first cam pair 700 (not shown); the second drive lug 750 mates with the second driven groove 25 to form a second cam pair 800 (not shown). The driving head 70 can move in a translational manner along the central axis direction, so that relative sliding is generated in the first cam pair 700 to drive the first jaw 10 to rotate around the first rotating pair 100; forcing the second cam pair 800 to slide relative to drive the second jaw 20 to rotate about the second revolute pair 200.

In a specific embodiment, the base 30, the driving head 70, the first jaw 10 and the second jaw 20 satisfy the following relationship: hj1 is equal to or greater than HP1, hj1 is equal to or greater than Hf1, hj2 is equal to or greater than HP2, hj2 is equal to or greater than Hf2, hj1+hj2+hd1+δ1=Hb1. Hj1 is the thickness of the first tail; hj2 is the thickness of the second tail; hd1 is the thickness of the drive block; hb1 is a distance between the first and second fixed arms; δ1 is a machining error.

Example 2:

Fig. 7-9 depict a further embodiment of the present invention, head assembly 2a. The reference numerals for the geometric structures in fig. 7-9 are the same as the corresponding reference numerals in fig. 1-6, meaning that the structures of the same reference numerals are substantially identical. The same reference numerals in the different embodiments hereafter denote substantially identical structures. The head assembly 2a includes a first jaw 10a, a second jaw 20a, a base 30 and a drive head 70.

Fig. 7 depicts in detail the structure and composition of the first jaw 10a (second jaw 20 a). The first jaw 10a (second jaw 20 a) is similar in construction to the first jaw 10 (second jaw 20) described above, with the primary difference being the arrangement of the base aperture and the driven slot. The first tail 13 of the first jaw 10a comprises a first base aperture 14a and a first driven slot 15a. The first base hole 14a includes a first cylindrical base surface 142a having a diameter Dr1 and a first cutout 141a having a width Br1, and the cutout 141a cuts out a part of the cylindrical base surface 142a to form a half-open structure. The first driven groove 15a includes a first groove distal end 159a and a first groove proximal end opening 151a having a width Ss 1. The second tail 23 of the second jaw 20a further comprises a second base aperture 24a and a second driven slot 25a. The second base hole 24a includes a second cylindrical base surface 242a having a diameter Dr2 and a second cutout 241a having a width Br2, and the cutout 241a cuts out a portion of the cylindrical base surface 242a to form a half-open structure. The second driven groove 25a includes a second groove distal end 259a and a second groove proximal opening 251a having a width dimension Ss 2. It will be appreciated by those skilled in the art that the values of Dr1 and Dr2, dr1 and Br1, dr2 and Br2 may be equal or different. In an alternative, the first boss 331 comprises a cylinder having a diameter Df1, and the second boss 341 comprises a cylinder having a diameter Df 2; where Df1, dr1, br1 are approximately equal and Df2, dr2, br2 are approximately equal.

The parts of the head assembly 2a cooperate, the driving and movement relationship of the assembly 2 described above being substantially identical, in general terms the first boss 331 being matched with the first base aperture 14a to form a first rotating pair 100a; the second boss 341 is matched with the second base hole 24a to form a second revolute pair 200a (not shown in the figure); the first drive lug 740 mates with the first driven slot 15a to form a first cam pair 700a; the mating of the second drive lug 750 with the second follower slot 25a forms a second cam pair 800a (not shown) and is understood with reference to fig. 8-9 and in conjunction with the foregoing, and will not be described in detail. For the convenience of observation and understanding, the base 30 is subjected to perspective (virtual) processing in fig. 8 and 9, and the two-dot line is indicated, and the structure indicated by the two-dot chain line is indicated hereinafter.

Referring now to fig. 8-9, in one specific design, the opening angle A1 of the first jaw 10a (or the second jaw 20 a) of the head assembly 2a is measured by: as shown in fig. 9, the rotation axis of the revolute pair is approximately parallel to the included angle between the virtual plane of the jaw and the buckling surface. The opening angle A1 comprises three value intervals: a limit opening angle Au1, a critical opening angle Ae1, and a working opening angle Aw1.

Limit opening angle Au1: there is a limit angle Au1, when A1. Gtoreq.Au 1, the first driving lug 740 is completely disengaged from the first driven groove 15a, and the first jaw 10a is rotatable about the first revolute pair 100a without interfering with the first driving lug 740.

Critical opening angle Ae1: there is a critical angle Ae1 such that when a1=ae 1, the first drive lug 740 is aligned with the first driven slot proximal opening 151 a; when A1 > Ae1, the first driving lug 740 is disengaged from the first driven groove 15 a; when A1 < Ae1, the first drive lug 740 mates with the first follower slot 15a to form a first cam pair 700a.

Working opening angle Aw1: the working angle Aw1 is present such that the first drive lug 740 remains in contact with the first driven groove 15a at all times when Aw1 is less than or equal to Aw 1.

In one embodiment, au1 > Ae1 > Aw1. In a specific embodiment, aw1 is 0 to 40.

The head assembly 2a can be conveniently and rapidly disassembled and assembled, and in the assembling and disassembling processes, a small pin shaft or other small scattered parts are not required to be assembled or disassembled, so that the assembling and disassembling efficiency can be improved to a large extent, the assembling cost and the finished product rejection rate are greatly reduced, and the overall cost of the disposable instrument is greatly reduced. Referring to fig. 8-9, first, the first boss 331 is matched with the first base hole 14a to form a first revolute pair 100a, and the second boss 341 is matched with the second base hole 24a to form a second revolute pair 200a; the first jaw is then rotated, the second jaw is set to an open angle set to the critical angle Ae1, and finally the drive head 70 is moved to cause the first drive lug 740 to enter and mate with the first driven slot 15a via the first slot proximal opening 151a to form the first cam pair 700a, while the second drive lug 750 enters and mates with the second driven slot 25a via the second slot proximal opening 251a to form the second cam pair 800a. It will be readily appreciated by those skilled in the art that a limit may be added such that the instrument 1 limits the opening angle A1 of the head assembly 2a to the range of working opening angles Aw1 during use, preventing the first jaw 10a (second jaw 20 a) from backing out during operation.

Example 3:

Fig. 10-12 depict yet another preferred head assembly 2b. The head assembly 2b includes a first jaw 10a, a second jaw 20a, a base 30b and a drive head 70. The structure and composition of the base 30b will now be understood with reference to fig. 10 in conjunction with fig. 1-2. The base 30b is similar in structure and composition to the base 30. Briefly, the base 30b includes a shoulder 31, a shaft hole 32, a motion base 371, a fastening surface 372, a first fixing arm 33, a second fixing arm 34, a first boss 331b, and a second boss 341b.

In one embodiment, the first boss 331b includes a first stationary cylindrical portion 333b having a cross-sectional diameter Df1 and a first narrow body feature 334b having a cross-sectional width Bf1, where Bf1 < Df1. In an alternative, the first cylindrical fixation portion 333b comprises two oppositely disposed cylindrical surfaces, and the first narrow body feature comprises two oppositely disposed tangential planes, however, it may comprise only one tangential plane or a shaped cut-out surface, forming a shaped cylinder 331b (or shaped prism 331 b) comprising a partial cylinder and a partial narrow body. In one implementation, the second boss 341b includes a second stationary cylindrical portion 343b having a cross-sectional diameter Df2 and a second narrow body feature 344b having a cross-sectional width Bf2, where Bf2 < Df2. In the alternative, the second cylindrical fixation portion 343b comprises two oppositely disposed cylindrical surfaces and the second narrow body feature 344b comprises two oppositely disposed tangential planes. In a preferred embodiment, the diameter Dr1 of the first cylindrical base surface 142a of the first jaw 10a, the width of the first notch 141a is Br1, and Dr1 is larger than or equal to Df1 > Br1 is larger than or equal to Bf1; the diameter Dr2 of the second cylindrical basal plane 242a of the second jaw 20a, the width of the second notch 241a is Br2, and Dr2 is larger than or equal to Df2 > Br2 is larger than or equal to Bf2.

The fitting relationship between the head assembly 2b and the components of the head assembly 2a is substantially identical, and the assembly method and the disassembly method are also substantially identical, and the main difference is in the assembly process of the first boss 331b and the first base hole 14a, and the second boss 341b and the second base hole 24 a. Briefly, the first narrow body feature 334b passes into the first base aperture 14a via the first cutout 142a, and the first jaw 10a is rotated to mate the first cylindrical base surface 142a with the first stationary cylindrical portion 333b to form the first rotating pair 100b; the second narrow body feature 344b is received into the first base aperture 24a via the second cutout 241a, and the second jaw 20a is rotated to mate the second cylindrical base surface 242a with the second fixed cylindrical portion 343b to form the second revolute pair 200b. The method of assembly and the kinematic relationships thereof will be readily understood by those skilled in the art with reference to fig. 11-12 and the foregoing and will not be described in detail herein.

The head assembly 2b is more precise and reliable than the head assembly 2 a. When the first jaw 10a (the second jaw 20 a) of the head assembly 2a is rotated to a certain angle, a shaking may occur between the first jaw 10a and the second jaw 20a, particularly when there is no clamping or shearing of tissue between the first jaw 10a and the second jaw 20a, i.e., there is no or little reaction force therebetween, which shaking is more pronounced. In the process that the first jaw 10a and the second jaw 20a of the head assembly 2b rotate to any angle during working (within the working angle range), the first cylindrical base surface 142a and the first fixed cylindrical portion 333b are tightly matched with each other, and the gap between the second cylindrical base surface 242a and the second fixed cylindrical portion 343b during the movement of the first jaw 10a and the second jaw 20a can be effectively reduced, so that better operation experience is obtained. In a preferred embodiment, the narrow body feature 334b forms an included angle Ap1 with the fastening surface 372, and the narrow body feature 344b forms an included angle Ap2 with the fastening surface 372, in a specific implementation, ap1 is less than or equal to 0 and less than or equal to 45 °, ap2 is less than or equal to 0 and less than or equal to 45 °, which is beneficial to increasing the dynamic fit area (dynamic contact area) of the cylindrical base surface and the fixed cylindrical portion when the first jaw 10a (the second jaw 20 a) rotates to any angle during operation, so that the fit is tighter, and precise feedback information is given to the surgeon during clinical application.

Example 4:

fig. 13-16 depict yet another head assembly 2c of the present invention. The head assembly 2c includes a first jaw 10c, a second jaw 20c, a base 30b and a drive head 70.

Fig. 13-14 depict the structure and composition of the first jaw 10c and the second jaw 20 c. The first jaw 10c (second jaw 20 c) is similar in construction to the first jaw 10a (second jaw 20 a) described above, with the primary difference being the arrangement of the base aperture and the driven slot. The first jaw 10c includes a first outer side 11, a first inner side 12, a first tail 13, a first wrist 16 and a first jaw head 19. The first base hole 14c is recessed from the first outer side surface 11 toward the inside of the tail, and the first driven groove 15c is recessed from the first inner side surface 12 toward the inside of the tail. The first base hole 14c includes a first cylindrical base surface 142c having a diameter Dr1 and a first cutout 141c having a width Br1, and the cutout 141c cuts out a part of the cylindrical base surface 142c to form a half-open structure. The first driven groove 15c includes a first driven groove distal end 159c and generally parallel groove sides extending from the groove distal end to the first driven groove proximal end 151 c. The slot proximal end 151c, slot sides and slot distal end 159c form a closed racetrack annular groove. Although the slot sides are shown as straight sides, curved sides may be used.

The second jaw 20c includes a second outer side 21, a second inner side 22, a second tail 23, a second wrist 26, and a second jaw head 29. The second base hole 24c is recessed from the second outer side surface 21 toward the inside of the tail, and the second driven groove 25c is recessed from the second inner side surface 22 toward the inside of the tail. The second base hole 24c includes a second cylindrical base surface 242c having a diameter Dr2 and a second cutout 241c having a width Br2, and the cutout 241c cuts out a portion of the cylindrical base surface 242c to form a half-open structure. The second driven groove 25c includes a second driven groove distal end 259c and generally parallel groove sides extending from the groove distal end to the second driven groove proximal end 251 c. The slot proximal end 251c, slot side and slot distal end 259c form a closed racetrack annular groove.

The main difference between the first jaw 10c and the first jaw 10a is that the first base hole 14c and the first driven groove 15c form a blind hole or blind groove (non-penetrating) structure, i.e. do not penetrate the first jaw tail 13, so that the strength of the jaw tail can be enhanced, sharp corners of the appearance of the instrument can be reduced, and accidental injuries in clinical application can be reduced. It will be appreciated by those skilled in the art that the base aperture 14c and the driven slot 15c may also partially or fully penetrate the first tail 13.

The composition and movement relationship of the head assembly 2c will now be understood in connection with fig. 15-16. The first jaw 10c and the second jaw 20c are sandwiched between the first fixed arm 33 and the second fixed arm 34 of the base 30c, the first base hole 14c and the first boss 331b form a first revolute pair 100c, and the second base hole 24c and the second boss 341b form a second revolute pair 200c (not shown). The first revolute pair 100c is not coaxial with the second revolute pair 200 c. The driving head 70 is clamped between the first jaw tail 13 and the second jaw tail 23, and the first driven groove 15c and the first driving lug 740 form a first cam pair 700c (not shown in the figure); the second follower chute 25c and the second drive lug 750 form a second cam pair 800c (not shown). The driving head 70 can move in a translational manner along the central axis direction, so that relative sliding is generated in the first cam pair 700c to drive the first jaw 10c to rotate around the first rotating pair 100 c; forcing the second cam pair 800c to slide relative to drive the second jaw 20c to rotate about the second revolute pair 200 c.

The head assembly 2c can be quickly disassembled and assembled, and a small pin shaft or other small scattered parts are not required to be mounted or dismounted in the assembly and disassembly processes. The assembly method and steps of the head assembly 2c are as follows:

S1, cooperation of the first jaw, the second jaw and the driving head: inserting first drive lug 740 into first driven slot 15c to form first cam pair 700c and inserting second drive lug 750 into second driven slot 25c to form second cam pair 800c, rotating the first and second jaws to mate first translation surface 74 with first inner side 12 and second translation surface 75 with second inner side 22; s2, matching with a base: loading the assembly assembled in step S1 together into the base 30b, first mating the first exterior side 11 with the first mounting surface 330 and the second exterior side 21 with the second mounting surface 340, and aligning the first narrow body feature 334b with the first cutout 141c and the second narrow body feature 344b with the second cutout 241c; the first and second jaws are then translated distally and proximally such that the first cylindrical base surface 142c mates with the first stationary cylindrical portion 333b to form a first revolute pair 100c and the second cylindrical base surface 242c mates with the second stationary cylindrical portion 343b to form a second revolute pair 200c (as will be appreciated with reference to fig. 15-16).

In one particular design, the shortest distance between the geometric centroid of the distal slot end 159c and the center of the first base aperture 14c along the engagement plane is Lj1, where Lj1 is greater than or equal to Ld1. The opening angle A1 of the first jaw 10c (or the second jaw 20 c) of the head assembly 2c, the opening angle A1 comprising two value intervals: the design disassembly opening angle Ac1 and the design working opening angle Aw1. Referring to fig. 15, when the angle Ac1 is removed, that is, the opening angle a1 is equal to or greater than Ac1, the first boss 331b is removed from the first base hole 14c (the second boss 341b is removed from the second base hole 24 c).

Example 5:

Fig. 17-20 depict yet another head assembly 2d. The head assembly 2d includes a first jaw 10d, a second jaw 20d, a base 30d and a drive head 70. Fig. 17-18 depict the structure and composition of the base 30d in detail. The base 30d is similar in structure and composition to the base 30. Briefly, the base 30d includes a shoulder 31, a shaft hole 32, a movement base 371, a fastening surface 372, a first fixing arm 33, and a second fixing arm 34. The distal end of the first fixing arm 33 includes a first fixing hole 331d recessed from the first mounting surface 330 toward the inside of the first fixing arm; the distal end of the second fixing arm 34 includes a second fixing hole 341d recessed from the second mounting surface 340 toward the inside of the second fixing arm. That is, the first boss 331 of the base 30 is replaced with the first fixing hole 331d, and the second boss 341 of the base 30 is replaced with the second fixing hole 341d to form a new base 30d.

Fig. 19 depicts in detail the structure and composition of the first jaw 10d and the second jaw 20 d. The first jaw 10d (second jaw 20 d) is structurally similar to the first jaw 10 (second jaw 20) previously described. Briefly, the first jaw 10d includes a first outer side 11, a first inner side 12, a first jaw tail 13, a first jaw wrist 16, a first jaw head 19 and a first driven groove 15, and the first base column 14d extends from the first outer side 11 to the outside of the jaw tail. I.e. the first base aperture 14 of the first jaw 10 is replaced by the first base post 14d, a new first jaw 10d is formed. The second jaw 20d includes a second outer side 21, a second inner side 22, a second jaw tail 23, a second jaw wrist 26, a second jaw head 29, and a second driven groove 25, and the second base column 24d extends from the second outer side 21 to the outside of the jaw tail. I.e. the second base aperture 14 of the second jaw 20 is replaced by the second base post 24d, a new second jaw 10d is formed.

Fig. 20 depicts the composition and assembly relationship of the head assembly 2 d. The first jaw 10d and the second jaw 20d are mounted in the base 30d, with a first mounting surface 330 matching the first outer side 11 and a second mounting surface 340 matching the second outer side 21. The first fixing hole 331d is matched with the first base column 14d to form a first rotating pair 100d; the second fixing hole 341d is matched with the second base column 24d to constitute a second revolute pair 200d (not shown). The drive head 70 is mounted into the base 30d with the first central axis 37 and the second central axis 71 aligned; the first translation surface 74 mates with the first inner side 12; the second translation surface 75 matches the second inner side 22; first drive lug 740 mates with first driven slot 15 to form first cam pair 700 (not shown); the second drive lug 750 mates with the second driven groove 25 to form a second cam pair 800 (not shown).

Example 6:

Fig. 21-24 depict yet another head assembly 2e of the present invention. The head assembly 2e comprises a first jaw 10e and a second jaw 20e, a base 30e and a drive head 70. As shown in fig. 21-22, the first jaw 10e (second jaw 20 e) is similar in construction to the first jaw 10d (second jaw 20 d) described above, with the primary difference being the arrangement of the base post and the driven slot. The first jaw 10e includes a first outer side 11, a first inner side 12, a first tail 13, a first wrist 16 and a first jaw head 19. The first tail 13 further comprises a first base column 14e extending from the first outer side surface 11 to the outside of the tail, and a first driven groove 15e recessed from the first inner side surface 12 to the inside of the tail. The first base column 14e includes a first cylindrical base 142e having a diameter Dr3 and a first narrow body feature 141e having a width Br3, with Br3 < Dr3. The first driven groove 15e includes a first driven groove distal end 159e and generally parallel first front and rear driven faces 153e, 155e extending from the groove distal end to the groove proximal end, with the front and rear driven faces 153e, 155e forming a first driven groove proximal end opening 151e having a width dimension Ss 1.

The second jaw 20e includes a second outer side 21, a second inner side 22, a second tail 23, a second wrist 26, and a second jaw head 29. The second tail 23 further includes a second base 24e extending from the second outer side 21 to the outside of the tail, and a second driven groove 25e recessed from the second inner side 22 to the inside of the tail. The second base column 24e includes a second cylindrical base 242e having a diameter Dr4 and a second narrow body feature 241e having a width Br4, with Br4 < Dr4. The second driven groove 25e includes a second driven groove distal end 259e and generally parallel second front and rear driven surfaces 253e, 255e extending from the groove distal end to the groove proximal end, with the front and rear driven surfaces 253e, 255e forming a second driven groove proximal opening 251e having a width dimension Ss 2. The first (second) driven groove does not penetrate through the first (second) jaw tail, so that the strength of the jaw tail can be enhanced, sharp corners on the appearance of the instrument can be reduced, and accidental injury in clinical application can be reduced. However, it may also be completely penetrated.

The structure and composition of the base 30e will now be understood with reference to fig. 24 in conjunction with fig. 17-18. The base 30e is similar in structure and composition to the base 30 d. Briefly, the base 30e includes a shoulder 31, a shaft hole 32, a movement base 371, a fastening surface 372, a first fixing arm 33, a second fixing arm 34, a first fixing hole 331e, and a second fixing hole 341e. The first fixing hole 331e includes a first cylindrical surface 333e having a diameter Df3 and a first cutout 334e having a width Bf3, and the cutout 334e cuts out a portion of the first fixing hole 331e to form a half-open structure. The second fixing hole 341e includes a second cylindrical surface 343e having a diameter Df4 and a second cutout 344e having a width Bf4, and the cutout 344e cuts out a portion of the second fixing hole 341e to form a half-open structure. That is, the first fixing hole 331d of the base 30d is replaced with a first fixing hole 331e having a cutout, and the second fixing hole 341d of the base 30d is replaced with a second fixing hole 341e having a cutout, thereby constructing a new base 30e. In a specific implementation scheme, df3 is more than or equal to Dr3 is more than or equal to Bf3 is more than or equal to Br3, df4 is more than or equal to Dr4 is more than or equal to Bf4 is more than or equal to Br4, and the values of Df1 and Df2, bf1 and Bf2 can be equal or unequal.

Referring now to fig. 23, the first jaw 10e and the second jaw 20e are sandwiched between the first fixed arm 33 and the second fixed arm 34 of the base 30e, the first fixed hole 331e and the first base column 14e form a first revolute pair 100e, and the second fixed hole 341e and the second base column 24e form a second revolute pair 200e. The first revolute pair 100e is not coaxial with the second revolute pair 200e. The driving head 70 is clamped between the first inner side 12 and the second inner side 22, and the first driven chute 15e and the first driving lug 740e form a first cam pair 700e (not shown in the figure); the second follower chute 25 and the second drive lug 750e constitute a second cam pair 800e (not shown).

Approximately, at the opening angle A2 of the first jaw 10e (or the second jaw 20 e) of the head assembly 2e, the opening angle A2 comprises three values: a limit angle Au2, a critical angle Ae2, and a working angle Aw 2. A2 When the temperature is equal to or higher than Au2, the first driving lug 740 is completely separated from the first driven groove 15 e; a2 When =ae2, the first drive lug 740 is aligned with the first driven slot proximal opening 151 e; A1.ltoreq.Aw1, the first driving lug 740 is always in contact with the first driven groove 15 e.

The head assembly 2e can be quickly disassembled and assembled, and a small pin shaft or other small scattered parts are not required to be mounted or dismounted in the assembly and disassembly processes.

Example 7:

Fig. 25-27 depict yet another head assembly 2f of the present invention. The head assembly 2f comprises a first jaw 10a and a second jaw 20d, a base 30f and a drive head 70. Referring now to fig. 25-26, the base 30f is substantially identical in structure to the base 30b (30 d). Briefly, the second fixing hole 341d replaces the second boss 341b in the base 30b to form a new base 30f. Referring now to fig. 27, the first jaw 10a and the second jaw 20d are clamped between the first fixed arm 33 and the second fixed arm 34 of the base 30f, the first outer side 11 is matched with the first mounting surface 330, the second outer side 21 is matched with the second mounting surface 340, the first boss 331b and the first base hole 14a form a first revolute pair 100b, and the second fixed hole 341d and the second base post 24d form a second revolute pair 200d. The first revolute pair 100b is not coaxial with the second revolute pair 200d. The drive head 70 is sandwiched between the first tail 13 and the second tail 23, and the first follower chute 15a and the first drive lug 740 form a first cam pair 700a; the second driven chute 25 and the second drive lug 750 form a second cam pair 800 (not shown). The head assembly 2f can be quickly disassembled and assembled, and a small pin shaft or other small scattered parts are not required to be mounted or dismounted in the assembly and disassembly processes.

Example 8:

Fig. 28-29 depict yet another head assembly 2g of the present invention. The head assembly 2g includes a first jaw 10g, a second jaw 20g, a base 30g and a drive head 70. The base 30g is similar in structure and composition to the base 30 f. Briefly, the base 30g includes a shoulder 31, a shaft hole 32, a movement base 371, a fastening surface 372, a first fixing arm 33, a second fixing arm 34, a first boss 331g, and a second fixing hole 341g. The first boss 331g includes a first stationary cylindrical portion 333b and a first narrow body feature 334b. The main difference between the base 30g and the base 30f is: the axis of the cylindrical portion 333b of the base 30g is coaxial with the axis of the second fixing hole 341g.

As shown in fig. 28, the first jaw 10g is similar in structure and composition to the first jaw 10 a. The first jaw 10g includes a first outer side 11, a first inner side 12, a first tail 13, a first wrist 16 and a first jaw head 19. The first base hole 14g is recessed from the first outer side surface 11 toward the inside of the tail 13, and the first driven groove 15g is recessed from the first inner side surface 12 toward the inside of the tail 13. The first base aperture 14g includes a first cylindrical base surface 142a and a first cutout 141g. The first follower groove 15g includes a first follower groove proximal opening 151g. The second jaw 20g is substantially identical in structure and composition to the second jaw 20d, differing primarily in the size and positional relationship of the second base.

Referring now to fig. 29, the first jaw 10g and the second jaw 20g are sandwiched between the first fixed arm 33 and the second fixed arm 34 of the base 30g, the first boss 331g and the first base hole 14g constitute a first revolute pair 100g, and the second fixed hole 341g and the second base post 24d constitute a second revolute pair 200g. The first revolute pair 100g is coaxial with the second revolute pair 200g. The drive head 70 is sandwiched between the first and second tails, and the first follower chute 15g and the first drive lug 740 form a first cam pair 700g; the second driven chute 25 and the second drive lug 750 form a second cam pair 800 (not shown).

Example 9:

Fig. 30-31 depict yet another elongate shaft assembly 2h. The elongate shaft assembly 2h comprises two first jaws 10h, a base 30b and a drive head 70h. Fig. 30 depicts the first jaw 10h. The first jaw 10h comprises a first jaw wrist 16h, a first jaw tail 13h connected thereto and extending to a proximal end, and a first jaw head 19h extending to a distal end; the first wrist 16h includes a first base aperture 14h recessed inwardly of the wrist from a first outer side 11h (not shown). The first base hole 14h includes a first cylindrical base surface 142h having a diameter Dr1 and a first cutout 141h having a width Br 1. The first cutout 141h cuts a portion of the first cylindrical base surface 142h to form a half-open structure. The first tail 13h includes a first driven chute 15h recessed inwardly of the tail from the first inner side 12h, the first driven chute 15h including a first chute distal end 159h and generally parallel first front and rear driven surfaces 153h, 155h extending from the chute distal end to the chute proximal end, the driven surfaces 153h and 155h forming a first chute proximal end opening 151h having a width dimension Sr 1. The first jaw wrist 16h also includes a first support surface 17h.

The driving head 70h is similar to the driving head 70 in structure, the driving head 70h includes a first translation surface 74, a second translation surface 75, a driving block 73, a driving neck 72, a first driving lug 740h extending from the translation surface 74 to the outside of the block 73, and a second driving lug 750h extending from the translation surface 75 to the outside of the block 73. The main difference between the drive head 70h and the drive head 70 is that the first drive lugs 740h and the second drive lugs 750d form a symmetrical structure.

Referring now to fig. 31, the two first jaws 10h are sandwiched between the first fixing arm 33 and the second fixing arm 34 of the base 30b, wherein the first supporting surfaces 17 are matched with each other, one of the first outer side surfaces 11h is matched with the first mounting surface 330, the other first outer side surface 11h is matched with the second mounting surface 340, the first boss 331b forms a first revolute pair 100h (not shown) with one of the first base holes 14h, and the second boss 341b forms a second revolute pair 200h (not shown) with the other first base hole 14 h. The first revolute pair 100h is not coaxial with the second revolute pair 200 h. The driving head 70h is clamped between the tails of two further first jaws 10h, wherein one of the first driven chute 15h and the first driving lug 740h form a first cam pair 700h (not shown); the other first follower chute 15h and the second drive lug 750h constitute a second cam pair 800h (not shown). Similarly, the slender shaft assembly 2h can be assembled or disassembled quickly, and no tiny pin shafts or other tiny scattered parts exist, so that the assembling and disassembling efficiency can be improved to a greater extent.

In yet another preferred embodiment, the elongate shaft assembly includes a base and first and second jaws mated thereto, the second jaw being configured and dimensioned to satisfy the following relationship: hw1+hw2+δ2=hb1; wherein Hw1 is the thickness of the first jawbone; hw2 is the thickness of the second jaw tail; hb1 is a distance between the first and second fixed arms; δ2 is a machining error.

Summarizing:

It will be appreciated by those skilled in the art that different designs may be created by substituting or combining different first (second) bosses, first (second) base holes, first (second) base posts, first (second) securing holes, first (second) cutouts, and first (second) narrow body features. For example, the first rotating pair may be constituted by the first boss and the first base hole, or may be constituted by the first fixing hole and the first base post. Based on the foregoing description one skilled in the art will understand that the following general language sets forth one of the inventive concepts:

In general terms, the first revolute pair comprises a first outboard pair (e.g. a fixed aperture on the fixed arm or a base aperture on the tail of the jaw) and a first inboard pair (e.g. a boss on the fixed arm or a base post on the tail of the jaw), and similarly the second revolute pair comprises a second outboard pair and a second inboard pair. In one aspect, the first outer pair comprises a partial cylindrical fixation surface and a cutout feature, the first inner pair comprises a partial cylindrical body and a narrow body feature, the partial cylindrical fixation surface and the partial cylindrical body form a first rotating pair, the first rotating pair is detachable when the first rotating pair rotates to align the narrow body feature and the cutout feature, and the first rotating pair can be rotationally detached. When the first revolute pair can be rotationally disassembled, the second revolute pair does not need to comprise a narrow body feature and a notch feature, and can still be conveniently disassembled. Of course, the second revolute pair may also similarly comprise a narrow body feature and a notch feature. Different combinations may vary the assembly method of the components or the refined performance differences, and more different technical feature combinations and alternatives are also conceivable. For economy of space, this is not exhaustive.

In yet another aspect of the invention, a head assembly includes a first jaw, a second jaw, and a base. The base comprises a shaft shoulder, a first fixing arm and a second fixing arm, wherein the first fixing arm and the second fixing arm extend to the far end, the shaft hole penetrates through the shaft shoulder, the movement base surface and the buckling surface are approximately perpendicularly intersected, and the intersection line of the movement base surface and the first central shaft of the shaft hole is basically coincident. The first jaw comprises a first tail and the second jaw comprises a second tail; the first and second jaw tails are sandwiched between the first and second fixed arms and are in free contact without additional pin fixation or additional fixation measures.

In an alternative embodiment, the first and second tails are sandwiched between first and second fixed arms, wherein the first tail and the first fixed arm form a first under-constrained revolute pair and the second tail and the second fixed arm form a second under-constrained revolute pair.

In a specific embodiment, the first under-constrained revolute pair comprises a first outer cylindrical surface and a first inner cylindrical surface; the first rotation axis of the first underconstrained revolute pair is approximately parallel to the buckling surface and approximately perpendicular to the movement base surface; the first outer cylinder and the first inner cylinder comprise 2 degrees of freedom, namely a rotational degree of freedom about the first rotational axis and a translational degree of freedom along the first rotational axis. Similarly, in a specific embodiment, the second under-constrained revolute pair comprises a second outer cylindrical surface and a second inner cylindrical surface; the second rotation axis of the second under-constrained revolute pair is approximately parallel to the buckling surface and approximately perpendicular to the movement base surface; the second outer cylinder and the second inner cylinder comprise 2 degrees of freedom, namely a rotational degree of freedom about the second rotational axis and a translational degree of freedom along the second rotational axis.

In the mechanics of the linkage, two members constituting the revolute pair (i.e., the fixed arm and the tail of the jaw described in the present invention) are usually studied as rigid bodies, and the two members constituting the revolute pair only allow rotational degrees of freedom about the rotational axis of the revolute pair without other degrees of freedom. The large number of standard revolute pairs used in minimally invasive surgical instruments has resulted in the background "staking of the joint pins" typically requiring multiple manual repairs by experienced advanced technicians and multiple verifications and confirmations, which greatly increases the manufacturing cost of the instrument.

In the invention, two members (the fixed arm and the jaw tail) forming the revolute pair are used as elastic bodies to study, the revolute pair is allowed to contain 2 degrees of freedom, and the first jaw tail and the second jaw tail are clamped between the first fixed arm and the second fixed arm and are in free contact without additional pin shaft fixing or additional fixing measures by utilizing the elastic deformation of the fixed arm and the stress characteristics in the operation of the minimally invasive surgical instrument. By utilizing the self-adaptive capacity of elastic deformation of the fixed arm, the first (second) under-constrained revolute pair can be ensured to be capable of not only enabling the firm connection part to fall off but also enabling the first (second) under-constrained revolute pair to smoothly rotate.

It will be appreciated by those skilled in the art that the first (second) boss disclosed in examples 1-9, the first (second) base cylinder is equivalent to the first (second) inner cylinder, the first (second) base hole, and the first (second) securing hole is equivalent to the first (second) outer cylinder.

Those skilled in the art will appreciate that the pedestals 30 (30 b,30D,30e,30f,30 g) and the drive heads 70 (70 h) may be manufactured by a variety of methods, such as by metal bar removal (e.g., milling) or by welding multiple parts in combination, or by 3D printing. In order to greatly reduce the manufacturing costs of the parts for use in disposable devices, it is preferable that the base 30 (30 b,30d,30e,30f,30 g) and the driving head 70 (70 h) are produced by metal powder injection molding (abbreviated as MIM process) or metal casting (abbreviated as MC process) or high-strength plastic injection molding (abbreviated as IM process). Particularly, the MIM technology is adopted for mass production, so that the requirements on precision and strength are met, and the cost of a single piece can be greatly reduced. In another preferred embodiment, the driving head 70 (70 h) is slightly adapted, and may be manufactured by sheet metal stamping.

In another aspect of the invention, an elongate shaft assembly for minimally invasive surgery is provided, the elongate shaft assembly comprising any of the head assemblies described above, a hollow tube coupled to a base of the head assembly, and a drive rod coupled to a drive head of the head assembly described above. In one version, as shown in FIGS. 32-33, the hollow tube 40 includes a tube distal end 41 and a tube proximal end 49 and a tube wall 45 extending therebetween, the tube wall 45 defining a central through bore 46 generally concentric with the shaft bore 32, the tube distal end 41 being connected to the shoulder 31. It will be appreciated by those skilled in the art that the base 30 (30 b,30e,30f,30g,30 h) and the hollow tube 40 may be attached by a variety of means including, but not limited to, welding, threading, glue bonding, and the like. As shown in fig. 33-34, the shoulder 31 preferably further includes a retaining wall 35 extending proximally. The outer surface of the fixed wall 35 may optionally further comprise one or more recessed portions 351 and/or one or more raised portions 353; however, the outer surface of the fixing wall 35 may be a flat surface or a curved surface having a smooth and non-convex structure. In an alternative embodiment, the hollow tube 40 is made of a thermoplastic material, and then the tube distal end 41 of the hollow tube 40 is coated on the outer surface of the fixing wall 35 by glue bonding, interference fit (which may be a heat assisted assembly), or two-shot molding (as shown in fig. 33). The secondary injection molding method is to put the base in a designed injection mold in advance and then to inject the hollow tube 40 to be connected into a whole. In yet another alternative, the hollow tube 40 is made of a metal material (e.g., stainless steel material), the tube distal end 41 of the hollow tube 40 is sleeved on the outer surface of the fixed wall 35 and the hollow tube 40 is connected to the fixed wall 35 by extrusion, for example, by applying an extrusion force to the outer periphery of the tube distal end 41 using a punching tool or a hydraulic tool to force the tube distal end 41 to shrink and deform inward to connect to the fixed wall 35.

35-39, The drive rod 80 includes a rod distal end 81 and a rod proximal end 89 and a rod portion 85 extending therebetween, the rod proximal end 89 including an annular slot 88 generally perpendicular to the drive rod axis, the rod distal end 81 being connected to the drive neck 72, the drive rod 80 axis generally coinciding with the second central axis 71. Those skilled in the art will appreciate that the drive head 70 (70 a,70e,70 f) may be coupled to the drive rod 80 by a variety of means including, but not limited to, welding, threading, mechanical staking (as shown in fig. 37), and the like. As shown in FIG. 36, preferably, snap-fit joints are employed between the drive heads 70 (70 a,70e,70 f) and the drive rod 80 for ease of manufacturing and quick assembly. In one implementation, the drive neck 72 further includes one or more male and female buttons 723, 721 extending to the proximal end, and the distal stem end 81 includes male and female buttons 813, 811. As shown in fig. 36, the male buckle 723 is matched with the female buckle 811, the female buckle 721 is matched with the male buckle 813 to form a snap joint 810, the snap joint 810 is designed to have an outer circumferential dimension approximately equal to the inner diameter of the shaft hole 32, and the snap joint 810 is always limited in the shaft hole 32 during the operation of the slender shaft assembly, thereby effectively preventing the snap joint 810 from falling off. The snap joint 810 depicted in fig. 36 is comprised of an asymmetric pin and box, but may also be comprised of a symmetric pin and box (as shown in fig. 38). In another embodiment, the snap-fit joint 810 is secured with additional welding or glue, and the snap-fit joint 810 need not be constrained within the shaft bore 32. In yet another embodiment, as shown in fig. 39, the drive neck 72 of the drive head 70 includes a semi-closed T-shaped slot 720c, and the distal stem end 81 includes an annular slot 84 mating therewith, the T-shaped slot 720c mating with the annular slot 84 to form a T-shaped joint 840.

In another aspect of the invention, a hand-held instrument for minimally invasive surgery is provided, comprising any of the foregoing elongate shaft assemblies, and further comprising a rotatable wheel 3 coupled to the elongate shaft assembly, a first handle 4 and a second handle 5. As shown in fig. 40, in one implementation, the handheld apparatus 1 includes any of the foregoing head assemblies, and further includes a hollow tube 40 connected to a base thereof, and a driving rod 80 connected to a driving head thereof, where the proximal tube end 49 is connected to the rotating wheel 3 and the first handle 4 at the same time, and the proximal rod end 89 is connected to the second handle 5, and the first handle 4 and the second handle 5 are mutually matched and rotatable about a handle rotation axis, so that the driving rod 80 and the hollow tube 40 generate axial relative movement, and further force the driving head to move axially, and further generate relative sliding in the first cam pair (the second cam pair), so as to drive the first jaw (the second jaw) to rotate about the first rotating pair (the second rotating pair), so as to realize opening and closing actions of the first jaw and the second jaw. In yet another design, the apparatus 1 further comprises an insulating tube wrapped around the hollow tube 40, the metal electrode is in communication with the hollow tube or the driving rod via a conductive reed, and the apparatus 1 can be used for surgical electrocoagulation, electroincision, etc. operations when the metal electrode assembly is connected to a high frequency electrosurgical device.

Although the elongate shaft assembly depicted in fig. 35-40 is rigid, the hollow tube 40 and drive rod 80 may be replaced with a flexible material or flexible mechanism, and the shaft assembly of the elongate shaft assembly exhibits overall flexibility, the instrument may be used for single hole transumbilical, urological, bronchial or digestive system procedures. The prior art to date has disclosed a wide variety of handle assemblies for minimally invasive procedures, with slight adaptations that can be used to attach and drive the elongate shaft assembly of the present invention, and will not be described in detail. Many different embodiments and examples of the invention have been shown and described. One of ordinary skill in the art will be able to make adaptations to the method and apparatus by appropriate modifications without departing from the scope of the invention. Several modifications have been mentioned, and other modifications are conceivable to the person skilled in the art. The scope of the present invention should therefore be determined with reference to the appended claims, rather than with reference to the structures, materials, or acts illustrated and described in the specification and drawings.

Claims

1. A head assembly for a minimally invasive surgical instrument, comprising a base and first and second jaws that cooperate with each other, wherein the first jaw comprises a first tail and the second jaw comprises a second tail; the base comprises a shaft shoulder, a first fixing arm and a second fixing arm, wherein the first fixing arm and the second fixing arm extend to the far end, the shaft hole penetrates through the shaft shoulder, the movement base surface and the buckling surface are approximately perpendicularly intersected, and the intersection line of the movement base surface and the buckling surface is basically coincident with a first central shaft of the shaft hole; the first jaw tail and the second jaw tail are clamped between the first fixed arm and the second fixed arm, the first jaw tail and the first fixed arm form a first revolute pair, the second jaw tail and the second fixed arm form a second revolute pair, the first revolute pair is an under-constrained revolute pair formed by a first outer cylindrical surface and a first inner cylindrical surface in a free contact mode without additional fixing measures, and the second revolute pair is an under-constrained revolute pair formed by a second outer cylindrical surface and a second inner cylindrical surface in a free contact mode without additional fixing measures; the assembly and disassembly of the first jaw, the second jaw and the base do not generate additional parts, and the assembly and disassembly of the first rotating pair and the second rotating pair do not generate additional parts except the first jaw, the second jaw and the base.

2. The head assembly of claim 1, the first revolute pair comprising a rotational degree of freedom about a first rotational axis and a translational degree of freedom along the first rotational axis; the second revolute pair comprises a rotational degree of freedom about a second rotational axis and a translational degree of freedom along the second rotational axis.

3. The head assembly of claim 1, wherein the first tail comprises a first inner cylinder integrally connected thereto and the first securing arm comprises a first outer cylinder integrally connected thereto.

4. The head assembly of claim 1, wherein the first tail comprises a first outer cylindrical surface integral therewith and the first securing arm comprises a first inner cylindrical surface integral therewith.

5. An elongate shaft assembly for minimally invasive surgery, comprising the head assembly of any one of claims 1-4, further comprising a drive head sandwiched between the first and second tails and a drive rod coupled to the drive head, the hollow tube coupled to the base shoulder; the hollow tube may be rigid or flexible and the drive rod may be rigid or flexible.