CN103815959A

CN103815959A - Bone screw

Info

Publication number: CN103815959A
Application number: CN201210464166.XA
Authority: CN
Inventors: 顾茂众; 彭树庆
Original assignee: Shanghai Detroit Precision Fastener Co Ltd
Current assignee: Shanghai Detroit Precision Fastener Co Ltd
Priority date: 2012-11-16
Filing date: 2012-11-16
Publication date: 2014-05-28

Abstract

The invention discloses a bone screw which comprises a head, a rod, a rod tail end and a cutting portion. The rod is provided with a threaded outer peripheral surface and comprises a calibration portion, and the cutting portion is provided with a front angle and a rear angle. The rod tail end mainly comprises a saw end and a flat end, but grooves, slots, notches or similarly drill-bit-shaped portions or the like with cutting functions can be machined at the rod tail end according to service functions. The bone screw has the advantages that working hours can be reduced, the operation efficiency can be improved, accordingly, suffering of patients can be relieved, and open surgical infection risks of patients can be reduced; squeezing load on threads at the rear of the bone screw can be reduced, the threads tapped by the self-tapping bone screw are high in quality, and the external threads and the internal threads of the bone screw can be reliably connected with one another.

Description

Bone screw

Technical field

The present invention relates to technical field of medical instruments, relate in particular to a kind of medical bone screw.

Background technology

Bone screw is a kind of internal fixation device for the treatment of fracture, and nail is made up of metal material, is mainly pure titanium, titanium alloy, cobalt-base alloys and rustless steel etc.Metal and Alloy material, has enough large intensity and toughness, and counter-bending and anti-torsion ability is strong, belongs to bio-inert material, with the combination of bone be the sealed of a kind of machinery.

For reducing operating time, reduce the use of apparatus in operation, a kind of self-drilling self-tapping nail is also applied clinically, as United States Patent (USP), the patent No.: 5797014.This self drilling tapping screw and common tapping screw difference be common tapping screw in the time being connected, must be through boring (brill thread Pilot hole) and tapping (comprise and being fastenedly connected) two procedures; And self drilling tapping screw is in the time connecting, just boring and the merging of tapping two procedures are once completed.It is first holed with the drill bit before screw, carries out tapping (comprise and being fastenedly connected) with that with screw, saves the engineering time, improves efficiency of construction.

Common self drilling tapping screw requires thread surface hardness higher, and the nip load of screw thread is larger, is screwed into moment high, and the screw of tapping is of low quality.In order to address the above problem, those skilled in the art is devoted to develop one and has low moment and the high locking property of being screwed into, and has the bone screw of better service behaviour than common tapping screw.

Applicant is engaged in research and development and the manufacture of screw thread and cutter measurer thereof for a long time, also start to set foot in recent years the development of medical apparatus and instruments and apparatus, for the problem of common bone screw and the existence of existing self drilling tapping screw, applicant is from different angle thinkings, screw tool is combined with nail operation principle, and open up thinking and be bold in innovation, obtain a kind of brand-new tapping screw structure.This is to only have the technical staff of medical background to be difficult to expect.

Summary of the invention

Because the above-mentioned defect of prior art, technical problem to be solved by this invention is to provide one and has low moment and the high locking property of being screwed into, and has the bone screw of better service behaviour than common tapping screw.

For achieving the above object, the invention provides a kind of bone screw.

Bone screw of the present invention, is made up of head, bar portion and end three parts.End mainly contains tip, flush end.But according to using function can process part of ditch, groove, otch or the similar drill-shape with cutting function etc.

Preferably, in the first preferred embodiments of the present invention, nail end thread is with cutting cone, each parameter (the flute profile of cutting cone, anterior angle, relief angle) can be with reference to screw tap, be equivalent to first tap out in endoporus of the former teeth of nail, the nip load that has reduced screw thread after nail, it is less that nail is screwed into moment.Before nail is screwed into, nail end fraction has entered endoporus, plays positioning action.Cutting cone is screwed in process and plays certain guide effect at nail, so little with the self tapping nail moment of cutting cone, the thread quality of tapping is higher, connects more reliable.

Preferably, in the second preferred embodiments of the present invention, the structure of the one section of similar drill bit in end, the cutting cone of the similar screw tap of the initial several teeth of threaded portion, has anterior angle and back-off, and identical with section shape figure in Fig. 6, flute profile is helicla flute.

The object of nail fluting is to form cutting edge (having positive anterior angle), has cutting function, separately has the bits of appearance function.The shape of groove is different.

Bone screw of the present invention, is made up of head, bar portion and end three parts, the threaded outer peripheral face of described bar portion's tool, and described bar portion comprises calibrated section, wherein also comprises cutting tip, described cutting tip is with anterior angle and relief angle.

Further, described bar portion terminal part is flush end.

Described anterior angle is 0～20 °, and described relief angle is 0～20 °.

Preferably, described anterior angle is 8～10 °, and described back-off is 6～8 °.

Axis direction in described bar portion has at least 1 chip pocket, to form cutting edge.

The end of described cutting edge is with taper lead angle.

Described taper lead angle is 0～25 °.

Described chip pocket is straight trough, spiral shell point type groove or helicla flute, and wherein said spiral shell point type has lower chip area at described terminal part.

Further, described nail end is most advanced and sophisticated and concentric with screw longitudinal axis, and the initial several teeth of threaded portion of described bar portion are with taper lead angle.

Described bar portion also comprises bit part, and described targeting part is made up of two symmetrical helicla flutes and land.

Described targeting part is made with back taper, to reduce and the friction of hole wall.

Described cutting tip comprises rake face, rear knife face and cutting edge.

Technique effect: bone screw of the present invention has reduced screw-in moment of torsion on the one hand, has reduced operator's working strength, has shortened the operating time; Second aspect cutting cone plays location and guide effect, has reduced operation easier, has shortened the operating time simultaneously; Above-mentioned advantage has alleviated patient's misery, has reduced the risk that patient's open surgery infects; The third aspect, cutting cone has tapping effect, has reduced the nip load of screw thread after nail, makes the thread quality of self tapping nail tapping higher, and nail external screw thread is more reliable with being connected of female thread.

Accompanying drawing explanation

Fig. 1 is the perspective view of the bone screw straight trough of a preferred embodiment of the present invention;

Fig. 2 is the front view of the bone screw of a preferred embodiment of the present invention;

Fig. 3 is the cutaway view of the A-A direction of the bone screw of a preferred embodiment of the present invention;

Fig. 4 is the fragmentary, perspective view of the bone screw spiral shell point type groove of a preferred embodiment of the present invention;

Fig. 5 is the bone screw spiral fluted fragmentary, perspective view of a preferred embodiment of the present invention;

The fragmentary, perspective view of the bone screw of Fig. 6 second preferred embodiment of the present invention.

The specific embodiment

Below with reference to accompanying drawing, the technique effect of design of the present invention, concrete structure and generation is described further, to understand fully object of the present invention, feature and effect.

As shown in Figure 1, bone screw of the present invention, is made up of head 1, bar portion 2 and end 3 three parts.End mainly contains tip, flush end.But according to using function can process part of ditch, groove, otch or the similar drill-shape with cutting function etc.

In the first preferred embodiments of the present invention, as shown in Figure 2, bar portion terminal part is flush end, and nail end thread is with cutting cone, the each parameter (flute profile of cutting cone, anterior angle, relief angle) can be with reference to screw tap, be equivalent to first tap out in endoporus of the former teeth of nail, reduce the nip load of screw thread after nail, make the thread quality of self tapping nail tapping higher, nail external screw thread is more reliable with being connected of female thread.The threaded outer peripheral face of bar portion tool, comprises calibrated section, wherein, also comprises cutting tip, and as shown in Figure 3, cutting tip is with anterior angle α and relief angle β.Anterior angle α is 0～20 °, and above-mentioned relief angle β is 0～20 °.

Preferably, anterior angle is 8～10 °, and relief angle is 6～8 °.

As shown in Figure 2, have at least 1 chip pocket 4 at the axis direction of bar portion, to form cutting edge.

The end of cutting edge, with taper lead angle Kr=0～25 °, is preferably 10 °.

The object of nail fluting is to form cutting edge (having positive anterior angle), has cutting function, separately has the bits of appearance function.The shape of groove is different.Chip pocket is straight trough, spiral shell point type groove or helicla flute, respectively as shown in Figure 1, Figure 4, Figure 5, wherein spiral shell point type endways portion have lower chip area 5.

Preferably, in the second preferred embodiments of the present invention, as shown in Figure 6, and the structure of the one section of similar drill bit in end, the cutting cone of the similar screw tap of the initial several teeth of threaded portion, has anterior angle and back-off, and identical with section shape figure in Fig. 3, flute profile is helicla flute.

End is most advanced and sophisticated and concentric with screw longitudinal axis.

End also comprises targeting part, and described targeting part is made up of two symmetrical helicla flutes and land.

Targeting part is made with back taper, to reduce and the friction of hole wall.Cutting tip comprises rake face, rear knife face and cutting edge.

More than describe preferred embodiment of the present invention in detail.The ordinary skill that should be appreciated that this area just can design according to the present invention be made many modifications and variations without creative work.Therefore, all technical staff in the art, all should be in by the determined protection domain of claims under this invention's idea on the basis of existing technology by the available technical scheme of logical analysis, reasoning, or a limited experiment.

Claims

1. a bone screw, is made up of head, bar portion and end three parts, the threaded outer peripheral face of described bar portion's tool, and described bar portion comprises calibrated section, it is characterized in that, also comprise cutting tip, described cutting tip is with anterior angle and relief angle.

2. bone screw as claimed in claim 1, is characterized in that, described bar portion terminal part is flush end.

3. bone screw as claimed in claim 1, is characterized in that, described anterior angle is 0～20 °, and described relief angle is 0～20 °.

4. bone screw as claimed in claim 3, is characterized in that, described anterior angle is 8～10 °, and described relief angle is 6～8 °.

5. bone screw as claimed in claim 1, is characterized in that, has at least 1 chip pocket, to form cutting edge at the axis direction of described bar portion.

6. bone screw as claimed in claim 5, is characterized in that, the end of described cutting edge is with taper lead angle.

7. bone screw as claimed in claim 6, is characterized in that, described taper lead angle is 0～25 °.

8. bone screw as claimed in claim 5, is characterized in that, described chip pocket is straight trough, spiral shell point type groove or helicla flute, and wherein said spiral shell point type has lower chip area in described end.

9. bone screw as claimed in claim 1, is characterized in that, described end is most advanced and sophisticated and concentric with screw axis, and the initial several teeth of threaded portion of described bar portion are with taper lead angle.

10. bone screw as claimed in claim 1, is characterized in that, described bar portion also comprises targeting part, and described targeting part is made up of two symmetrical helicla flutes and land.

11. bone screws as claimed in claim 10, is characterized in that, described targeting part is made with back taper, to reduce and the friction of hole wall.

12. bone screws as claimed in claim 1, is characterized in that, described cutting tip comprises rake face, rear knife face and cutting edge.