The application is the applying date is that 2014 05 month 26 day, are called: a kind of die assembly for the manufacture of cable air-blowing pipeline, application number are: the divisional application of the patent of invention of 201410224423.1.
Summary of the invention
In order to solve the problem, the object of the invention is to disclose a kind of die assembly for the manufacture of cable air-blowing pipeline, it realizes by the following technical solutions.
For the manufacture of a die assembly for cable air-blowing pipeline, it is characterized in that it includes core rod, die cap, plunger body, core rod includes core rod convex body 22, core rod groove 21 between adjacent core rod convex body, core rod convex body and the spaced formation of core rod groove have the column of the mold core cavities 23 of hollow, one end of this column is closed, and the outside of this blind end has a core rod connector 25, core rod connector inside has-core rod connecting hole 24, die cap has die cap body 31, and die cap body interior is the die cap chamber 4 of hollow, and die cap body has the through injecting hole 32 to die cap chamber, the inwall of die cap is cylindrical shape, plunger body includes plunger 11 and is positioned at the plunger connector 12 of plunger at one end, when manufacturing cable with air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap.
For the manufacture of a die assembly for cable air-blowing pipeline, it is characterized in that it includes core rod, die cap, plunger body, core rod includes core rod convex body 22, core rod groove 21 between adjacent core rod convex body, core rod convex body and core rod groove is spaced and below is continuous print core rod inner wall 26, for having the column of the mold core cavities 23 of hollow below core rod body inwall, one end of this column is closed, and the outside of this blind end has a core rod connector 25, core rod connector inside has-core rod connecting hole 24, die cap has die cap body 31, and die cap body interior is the die cap chamber 4 of hollow, die cap body has the through injecting hole 32 to die cap chamber, plunger body includes plunger 11 and is positioned at the plunger connector 12 of plunger at one end, when manufacturing cable with air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, the inwall that it is characterized in that die cap has at least one die cap groove 33.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod groove is triangular prism shape or arc column shape or trapezoidal column shape.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod convex body is triangular prism shape or other suitable shape.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod groove is parallel to each other.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod convex body is parallel to each other.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod, die cap, plunger body are all integral structures.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod connecting hole inwall has internal thread; Described core rod connector outer surface has thread.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that the material of described core rod is steel or pottery, and the material of die cap is steel or pottery, and the material of plunger body is steel or pottery.
Principle of the present invention is such: when manufacturing cable air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap, extrusion molding machine is outputed, and air-blowing pipeline material material is melted, the material melted injects injecting hole continuously, and enter in die cap chamber, and fill die cap chamber, because injection hole pressure is larger, therefore, the material melted can only overflow from die cap chamber, one end due to die cap chamber to be fixed on extrusion molding machine and to close envelope, therefore can only overflow in another port, die cap chamber, because another port temperature is lower, normally through Air flow and water cooling, crystallization rapidly after cooling, cable air-blowing pipeline is defined like this by traction, the air-blowing pipeline formed has air-blowing tube body, air-blowing tube body have air-blowing pipe convex body and air-blowing pipe guiding gutter, centre is formed with air-blowing tube passage.
Certainly, when the inwall of die cap having die cap groove, the air-blowing pipeline formed has projecting member, when forming the air-blowing pipeline of compound further, during extrusion molding, projecting member is embedded in air-blowing pipe outer tube body, the ectonexine of air-blowing pipe is made to combine so more firm, more easily form integral structure, in this case, do not need other sticky gelatin substance air-blowing pipeline and air-blowing pipe outer tube body to be bondd; And when there is no a projecting member, adopt bonding mode that structure can be made more stable, constructing, coiling time two-layerly not depart from, extra air-blowing resistance can not be produced when constructing.
Plunger body is cylindrical shape, and the plunger connector of plunger body is fixed on the core rod connecting hole of core rod, therefore, ensure that the formation of the air-blowing tube passage of air-blowing pipeline; In addition, plunger body stretches out the end face of mold core cavities without one end of plunger, due to during fabrication, the head of extrusion molding machine has a segment distance to the spacing of bosh, what therefore define pull-tube type during actual production extrudes mode, also namely the appearance and size of the air-blowing pipeline at bosh place than head place smaller of extrusion molding machine, like this, make the air-blowing tube body of air-blowing pipeline to have air-blowing pipe convex body and air-blowing pipe guiding gutter, and the air-blowing pipeline formed is desired shape; When core rod convex body and core rod groove is spaced and below is continuous print core rod inner wall time, the wall of the air-blowing tube body of the cable air-blowing pipeline formed just can be relatively thick.
The present invention has following main beneficial effect: mould structure is simple, easily make, wear-resisting, easily use; The air-blowing pipeline quality manufactured is stable, reliable, resistance to be turned round.
Detailed description of the invention
The application can be understood more accurately for making those skilled in the art, now the mark of the accompanying drawing related in the present invention is explained as follows: 11-plunger, 12-plunger connector, 21-core rod groove, 22-core rod convex body, 23-mold core cavities, 24-core rod connecting hole, 25-core rod connector, 26-core rod inner wall, 31-die cap body, 32-injecting hole, 33-die cap groove, 4-die cap chamber, 5-air-blowing tube body, 211-air-blowing pipe convex body, 221-air-blowing pipe guiding gutter, 231-air-blowing tube passage, 6-projecting member, 7-air-blowing pipe outer tube body.
embodiment 1
Ask for an interview Fig. 1 to Fig. 4, a kind of die assembly for the manufacture of cable air-blowing pipeline, it is characterized in that it includes core rod, die cap, plunger body, core rod includes core rod convex body 22, core rod groove 21 between adjacent core rod convex body, core rod convex body and the spaced formation of core rod groove have the column of the mold core cavities 23 of hollow, one end of this column is closed, and the outside of this blind end has a core rod connector 25, core rod connector inside has-core rod connecting hole 24, die cap has die cap body 31, and die cap body interior is the die cap chamber 4 of hollow, and die cap body has the through injecting hole 32 to die cap chamber, the inwall of die cap is cylindrical shape, plunger body includes plunger 11 and is positioned at the plunger connector 12 of plunger at one end, when manufacturing cable with air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap.
Die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod groove is triangular prism shape.
Die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod convex body is triangular prism shape.
Die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod groove is parallel to each other.
Die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod convex body is parallel to each other.
Die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod, die cap, plunger body are integral structures.
Die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod connecting hole inwall has internal thread; Described core rod connector outer surface has thread.
Die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that the material of described core rod is steel, and the material of die cap is steel, and the material of plunger body is steel.
The principle of this embodiment is such: when manufacturing cable air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap, extrusion molding machine is outputed, and air-blowing pipeline material material is melted, the material melted injects injecting hole continuously, and enter in die cap chamber, and fill die cap chamber, because injection hole pressure is larger, therefore, the material melted can only overflow from die cap chamber, one end due to die cap chamber to be fixed on extrusion molding machine and to close envelope, therefore can only overflow in another port, die cap chamber, because another port temperature is lower, normally through Air flow and water cooling, preferably a bit of from extrusion head is Air flow, then water cooling is entered, crystallization rapidly after cooling, cable air-blowing pipeline is defined like this by traction, the air-blowing pipeline formed has air-blowing tube body 5, air-blowing tube body have air-blowing pipe convex body 211 and air-blowing pipe guiding gutter 221, centre is formed with air-blowing tube passage 231.
Plunger body is cylindrical shape, and the plunger connector of plunger body is fixed on the core rod connecting hole of core rod, therefore, ensure that the formation of the air-blowing tube passage of air-blowing pipeline; In addition, plunger body stretches out the end face of mold core cavities without one end of plunger, due to during fabrication, the head of extrusion molding machine has a segment distance to the spacing of bosh, what therefore define pull-tube type during actual production extrudes mode, also namely the appearance and size of the air-blowing pipeline at bosh place than head place smaller of extrusion molding machine, like this, make the air-blowing tube body of air-blowing pipeline to have air-blowing pipe convex body and air-blowing pipe guiding gutter, and the air-blowing pipeline formed is desired shape.
embodiment 2
Ask for an interview Fig. 5, Fig. 6 and referring to figs. 1 to Fig. 4, a kind of die assembly for the manufacture of cable air-blowing pipeline, basic with embodiment 1, difference is: core rod convex body and core rod groove is spaced and below is continuous print core rod inner wall 26, for having the column of the mold core cavities 23 of hollow below core rod body inwall, the wall of the air-blowing tube body of the cable air-blowing pipeline formed is just relatively thick, and air-blowing pipeline is more solid, but material consumption is relatively many; The material of described core rod, die cap, plunger body is all pottery; Because pottery has high temperature resistant, wear-resistant, the effect such as acid and alkali-resistance, easy cleaning, therefore, die assembly is quite durable in use, after using 200 times still resemble new, and the die assembly adopting Steel material to make, after use more than 10 time, just there is larger wear phenomenon.
embodiment 3
Ask for an interview Fig. 7 to Figure 10, a kind of die assembly for the manufacture of cable air-blowing pipeline, basic with embodiment 2, difference is: described core rod convex body is arc column shape, core rod groove is approximate trapezoid post shapes, the air-blowing pipe guiding gutter of the air-blowing pipeline that this mode is formed is larger, and can bear higher pressure during air-blowing, air-blowing speed is faster.
embodiment 4
Ask for an interview Figure 11 to Figure 18, a kind of die assembly for the manufacture of cable air-blowing pipeline, it is characterized in that it includes core rod, die cap, plunger body, core rod includes core rod convex body 22, core rod groove 21 between adjacent core rod convex body, core rod convex body and core rod groove is spaced and below is continuous print core rod inner wall 26, for having the column of the mold core cavities 23 of hollow below core rod body inwall, one end of this column is closed, and the outside of this blind end has a core rod connector 25, core rod connector inside has-core rod connecting hole 24, die cap has die cap body 31, and die cap body interior is the die cap chamber 4 of hollow, die cap body has the through injecting hole 32 to die cap chamber, plunger body includes plunger 11 and is positioned at the plunger connector 12 of plunger at one end, when manufacturing cable with air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap, the inwall of die cap has a die cap groove 33.
Principle repeats no more with embodiment 1, due to the inwall of die cap having die cap groove, therefore the air-blowing pipeline formed has projecting member, when forming the air-blowing pipeline of compound further, during extrusion molding, projecting member is embedded in air-blowing pipe outer tube body, the ectonexine of air-blowing pipe is made to combine so more firm, more easily form integral structure, in this case, do not need other sticky gelatin substance air-blowing pipeline and air-blowing pipe outer tube body to be bondd; And when there is no a projecting member, adopt bonding mode that structure can be made more stable, constructing, coiling time two-layerly not depart from, extra air-blowing resistance can not be produced when constructing.
Obviously, in the die assembly of cable air-blowing pipeline described above, the inwall upper mould cover groove 33 of described die cap can be multiple.
Certainly, when producing cable with air-blowing pipeline, shutoff components and parts can be adopted to block die cap groove, produce the cable air-blowing pipeline as shown in Figure 17,18, make the purposes of die assembly wider like this.
embodiment 5
Ask for an interview Figure 19 to Figure 20, for one section of air-blowing pipeline that produces after adopting the core rod of embodiment 2 and the die cap of embodiment 4 cut open after perspective view; This cable air-blowing pipeline has the projecting member 6 that protrudes from air-blowing tube body 5; The existence of projecting member, can make air-blowing pipeline locate better.
Certainly, projecting member can also be multiple, or is other shape.
embodiment 6
Asking for an interview Figure 21, and reference implementation example 4-embodiment 5, is do further processing to embodiment 5, a section of the air-blowing pipeline of manufacture cut open after perspective view; The inwall of die cap has die cap groove, the air-blowing pipeline formed has projecting member, when forming the air-blowing pipeline of compound further, during extrusion molding, projecting member is embedded in air-blowing pipe outer tube body 7, makes the ectonexine of air-blowing pipe combine so more firm, more easily forms integral structure, in this case, other sticky gelatin substance is not needed air-blowing pipeline and air-blowing pipe outer tube body to be bondd; And when there is no a projecting member, adopt bonding mode that structure can be made more stable, constructing, coiling time two-layerly not depart from, extra air-blowing resistance can not be produced when constructing.
Certainly, the die assembly for the manufacture of cable air-blowing pipeline in above-mentioned embodiment 2-5, it also can include core rod, die cap, plunger body, core rod includes multiple core rod convex body 22, core rod groove 21 between adjacent core rod convex body, core rod convex body and the spaced formation of core rod groove have the column of the mold core cavities 23 of hollow, one end of this column is closed, and the outside of this blind end has a core rod connector 25, core rod connector inside has-core rod connecting hole 24, die cap has die cap body 31, and die cap body interior is the die cap chamber 4 of hollow, and die cap body has the through injecting hole 32 to die cap chamber, the inwall of die cap is cylindrical shape, plunger body includes plunger 11 and is positioned at the plunger connector 12 of plunger at one end, when manufacturing cable with air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap.
Certainly, the die assembly for the manufacture of cable air-blowing pipeline in above-mentioned embodiment 1-3, it also can include core rod, die cap, plunger body, core rod includes core rod convex body 22, core rod groove 21 between adjacent core rod convex body, core rod convex body and core rod groove is spaced and below is continuous print core rod inner wall 26, for having the column of the mold core cavities 23 of hollow below core rod body inwall, one end of this column is closed, and the outside of this blind end has a core rod connector 25, core rod connector inside has-core rod connecting hole 24, die cap has die cap body 31, and die cap body interior is the die cap chamber 4 of hollow, die cap body has the through injecting hole 32 to die cap chamber, plunger body includes plunger 11 and is positioned at the plunger connector 12 of plunger at one end, when manufacturing cable with air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, the inwall that it is characterized in that die cap all can have at least one die cap groove 33.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod groove part can be triangular prism shape or arc column shape or trapezoidal column shape.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod convex body can be triangular prism shape or other suitable shape.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod groove is parallel to each other.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod convex body is parallel to each other.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod, die cap, plunger body are all integral structures.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that described core rod connecting hole inwall can also have internal thread; Described core rod connector outer surface also can have thread simultaneously.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that the material of described core rod, die cap, plunger body all can be steel or pottery.
Any one die assembly for the manufacture of cable air-blowing pipeline described above, is characterized in that the outward flange of all core rod convex body is on same cylindrical side; There will not be weight uneven in the cable air-blowing pipeline symmetry that this structure produces, Stability Analysis of Structures, construction and produce free rolling phenomenon.
Principle of the present invention is such: when manufacturing cable air-blowing pipeline, core rod is arranged on the head of extrusion molding machine by core rod connector, die cap is fixedly mounted on the head of extrusion molding machine by one end of die cap body, and die cap is positioned at core rod outside, core rod is positioned at die cap chamber, the plunger connector of plunger body is fixed in the core rod connecting hole of core rod, a part for the plunger of plunger body is arranged in mold core cavities, plunger body stretches out the end face of mold core cavities without one end of plunger, core rod convex body and die cap cavity wall are discontiguous, the end face of the other end of the column of mold core cavities does not exceed the end face of the other end of die cap, extrusion molding machine is outputed, and air-blowing pipeline material material is melted, the material melted injects injecting hole continuously, and enter in die cap chamber, and fill die cap chamber, because injection hole pressure is larger, therefore, the material melted can only overflow from die cap chamber, one end due to die cap chamber to be fixed on extrusion molding machine and to close envelope, therefore can only overflow in another port, die cap chamber, because another port temperature is lower, normally through Air flow and water cooling, crystallization rapidly after cooling, cable air-blowing pipeline is defined like this by traction, the air-blowing pipeline formed has air-blowing tube body, air-blowing tube body have air-blowing pipe convex body and air-blowing pipe guiding gutter, centre is formed with air-blowing tube passage.
Certainly, when the inwall of die cap having die cap groove, the air-blowing pipeline formed has projecting member, when forming the air-blowing pipeline of compound further, during extrusion molding, projecting member is embedded in air-blowing pipe outer tube body, the ectonexine of air-blowing pipe is made to combine so more firm, more easily form integral structure, in this case, do not need other sticky gelatin substance air-blowing pipeline and air-blowing pipe outer tube body to be bondd; And when there is no a projecting member, adopt bonding mode that structure can be made more stable, constructing, coiling time two-layerly not depart from, extra air-blowing resistance can not be produced when constructing.
Plunger body is cylindrical shape, and the plunger connector of plunger body is fixed on the core rod connecting hole of core rod, therefore, ensure that the formation of the air-blowing tube passage of air-blowing pipeline; In addition, plunger body stretches out the end face of mold core cavities without one end of plunger, due to during fabrication, the head of extrusion molding machine has a segment distance to the spacing of bosh, what therefore define pull-tube type during actual production extrudes mode, also namely the appearance and size of the air-blowing pipeline at bosh place than head place smaller of extrusion molding machine, like this, make the air-blowing tube body of air-blowing pipeline to have air-blowing pipe convex body and air-blowing pipe guiding gutter, and the air-blowing pipeline formed is desired shape; When core rod convex body and core rod groove is spaced and below is continuous print core rod inner wall time, the wall of the air-blowing tube body of the cable air-blowing pipeline formed just can be relatively thick.
Certainly, the present invention in use, can adopt the technology of shutoff completely, and part core rod groove or whole core rod groove are carried out shutoff, like this, when the cable of production same size is with air-blowing pipeline, can control the quantity of core rod groove selectively.
The air-blowing pipeline of embodiment 5 is adopted to carry out laying test, ectonexine is all high-density polyethylene material, repeatedly around putting 238 times, there are no the segregation phenomenon of air-blowing pipe outer tube body and interior tube body, and adopt the air-blowing pipeline not having the interior pipe of projecting member and outer tube to make, repeatedly lay the inner and outer pipes lamination just having occurred many places for 3 times; During production, after employing viscose glue carries out inner and outer pipes bonding, carry out equally laying test, also only withstood the test of 12 times, when the 13rd time, just occurred layering; To above-mentioned three samples, each sample is 800 meters, at 10 sections, the air-blowing pipeline that each random intercepting 1.5 meters of length direction is long, air-blowing outer diameter tube is 24mm, carry out ± 180 degree, bear a heavy burden for 150N, speed are the test of 10 beats/min, 10 samples of embodiment 5, the torsion through 30 minutes has no cracking and lamination; And do not bond, after 6 times are reversed, just there is lamination; Bonding, after 38 times, there is lamination; Therefore, the air-blowing pipeline of the Making mold of embodiment 5 have more excellent resistance toly to turn round, folding quality.
The present invention has following main beneficial effect: mould structure is simple, easily make, wear-resisting, easily use; The air-blowing pipeline quality manufactured is stable, reliable, resistance to be turned round.
The present invention is not limited to above-mentioned preferred forms, and should be appreciated that design of the present invention can be implemented to use by other various forms, they drop in protection scope of the present invention equally.