CN104832521A

CN104832521A - Double-thread screw, screw-like structure and bolt

Info

Publication number: CN104832521A
Application number: CN201510203976.3A
Authority: CN
Inventors: 不公告发明人
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-04-27
Filing date: 2015-04-27
Publication date: 2015-08-12

Abstract

The invention relates to a double-thread screw, a screw-like structure and a bolt which can be used for the field of hardware and manufacturing. The double-thread screw comprises a screw body part of the screw, right-hand turning external threads and left-hand turning external threads; the right-hand turning external threads and the left-hand turning external threads are correspondingly arranged on two sides of the screw body part of the screw and are not mutually staggered; a right-hand turning nut and/or a left-hand turning nut can be arranged on the screw; the screw can be used as an ordinary screw; besides, the right-hand turning nut and the left-hand turning nut can be simultaneously arranged on the screw and are mutually attached and mutually constrained, so that the possibility of loosening is low, and the problem that the nut is easy to loosen after being arranged on the ordinary screw under the vibration environment is solved; on the premise of not influencing the functions of the double-thread screw, the structural shape formed of the double-thread screw after cutting can be used as another type of double-thread screw, and further a double-thread screw-like structure can be derived, so that the application field is widened, for example, a double-thread-like screw or the double-thread screw-like structure can be used as a mechanical rod piece. The screw and a bolt head can form the bolt.

Description

Two-flight screw, class screw-rod structure and bolt

Technical field

The present invention relates to two-flight screw, class screw-rod structure and bolt, belong to five metals and manufacture field.

Background technique

Existing screw rod, bolt and some have externally threaded object substantially all can only go up with dextrorotation internal thread object (as: positive spin nut, dextrorotation bottle cap etc.) or with derotation internal thread object (as: derotation nut, derotation bottle cap etc.), under vibration environment, easily loosen with dextrorotation internal thread object or with derotation internal thread object.

Summary of the invention

Two-flight screw of the present invention, class screw-rod structure and bolt, object is: even if under vibration environment, and what two-flight screw, class screw-rod structure and bolt tightened is not easy to loosen with dextrorotation internal thread object with derotation internal thread object.And this two-flight screw, class screw-rod structure and bolt can also as common screw on dextrorotation internal thread object or with derotation internal thread object.

Technological scheme of the present invention is as follows.

Scheme one: a kind of two-flight screw.

This two-flight screw, comprises screw rod rod body, dextrorotation outside thread and derotation outside thread.

Dextrorotation outside thread is located at screw rod rod body side, and derotation outside thread is located at screw rod rod body opposite side, and they do not interlock mutually, and dextrorotation outside thread is contrary with the externally threaded sense of rotation of derotation.

Dextrorotation outside thread and derotation outside thread are imperfect threads.

The use of this structure can coordinate the positive spin nut matched or/and derotation nut.

Dextrorotation nut inner thread matches with dextrorotation outside thread and is closely engaged, positive spin nut can rotate along the externally threaded path of dextrorotation, the each several part that derotation outside thread is set to its whole outer rim all has an opportunity to be close to the internal thread inner edge of the positive spin nut that screw rod screws, derotation outside thread is not engaged with dextrorotation nut inner thread, and now derotation outside thread just plays the effect limiting positive spin nut transverse shifting.

Derotation nut inner thread matches with derotation outside thread and is closely engaged, derotation nut can rotate along the externally threaded path of derotation, the each several part that dextrorotation outside thread is set to its whole outer rim all has an opportunity to be close to the internal thread inner edge of the derotation nut that screw rod screws, dextrorotation outside thread is not engaged with derotation nut inner thread, and now dextrorotation outside thread just plays the effect of restriction derotation nut transverse shifting.

The each several part of the whole outer rim of above-mentioned dextrorotation outside thread can share a cylndrical surface, and each several part of the whole outer rim of above-mentioned derotation outside thread can share another cylndrical surface.

Under screw rod rod body, dextrorotation outside thread and the externally threaded acting in conjunction of derotation, nut can only be longitudinally in rotary moving along screw rod, laterally can not rock, move.

Positive spin nut and derotation nut can be used on this screw rod simultaneously, when positive spin nut and derotation nut mutually lock fit together time, positive spin nut and derotation nut restrict rotation mutually, even if under vibration environment, also not easily mutually unclamp.

This screw rod also can as the common screw upper positive spin nut or derotation nut, but having of not having is above-mentioned prevents loosening effect.

The dextrorotation outside thread of above-mentioned two-flight screw or the externally threaded tooth form of derotation are not limit, and its tooth form can be set to triangle tooth form, trapezoidal tooth form, rectangle tooth form, arc tooth form or other various rational tooth forms.

The dextrorotation outside thread of above-mentioned two-flight screw can be arranged to the same with the externally threaded tooth form of derotation, dental floss line number, pitch and dental floss radius, also can be arranged to different.

Scheme two: another kind of two-flight screw.

This two-flight screw structure shape is identical by the structure shape formed after reasonable cutting with the two-flight screw described in scheme one.

Above-mentioned cutting position can at dextrorotation outside thread or/and derotation outside thread be or/and screw rod rod body.

The use of this screw rod can coordinate the positive spin nut matched or/and derotation nut.

Dextrorotation nut inner thread matches with dextrorotation outside thread and is closely engaged, positive spin nut can rotate along the externally threaded path of dextrorotation, the each several part that derotation outside thread is set to the most peripheral outer rim of part equal radii on it all has an opportunity to be close to the internal thread inner edge of the positive spin nut that screw rod screws, derotation outside thread is not engaged with dextrorotation nut inner thread, and now derotation outside thread just plays the effect limiting positive spin nut transverse shifting.

Derotation nut inner thread matches with derotation outside thread and is closely engaged, derotation nut can rotate along the externally threaded path of derotation, the each several part that dextrorotation outside thread is set to the most peripheral outer rim of part equal radii on it all has an opportunity to be close to the internal thread inner edge of the derotation nut that screw rod screws, dextrorotation outside thread is not engaged with derotation nut inner thread, and now dextrorotation outside thread just plays the effect of restriction derotation nut transverse shifting.

The each several part of the most peripheral outer rim of described dextrorotation outside thread part equal radii can share a cylndrical surface, and each several part of the most peripheral outer rim of described derotation outside thread part equal radii can share another cylndrical surface.

Compared with front a kind of two-flight screw, this two-flight screw more can save material, still can fastening positive spin nut or/and derotation nut, and identical effect can be reached.

Scheme three: a kind of two screw thread class screw-rod structure bodies for screwing thereon with internal thread object.

Structure shape [1] shape of the hollow formed after this pair of screw thread class screw-rod structure shape is cut in the middle part of rod body with above-mentioned two-flight screw structure is identical, and the principle that this pair of screw thread class screw-rod structure body screws with internal thread object is identical with the principle of screw on nut on above-mentioned two-flight screw.

This pair of screw thread class screw-rod structure body is the extension of above-mentioned two-flight screw application, as: because this pair of screw thread class screw-rod structure body is hollow, therefore can nozzle structure or bottleneck structure be used as.

Scheme four: a kind of bolt.

This bolt, applies above-mentioned two-flight screw, and adds bolt head.

The above-mentioned pair of screw thread class screw rod and two screw thread class screw-rod structure body not only can be applicable to fastening object, also can be used as the rod member of machinery, thus for the transmission of object.

Accompanying drawing explanation

For further illustrating the present invention, incorporated by reference to the following drawings in describing in detail thereafter.

Fig. 1 is the schematic perspective view overlooked above one end of the first preferred embodiment of two-flight screw of the present invention and A-A sectional schematic diagram thereof.

Fig. 2 is the schematic perspective view that Fig. 1 two-flight screw is overlooked above side.

Fig. 3 is the schematic perspective view that Fig. 1 two-flight screw is overlooked above opposite side.

Fig. 4 is the sectional schematic diagram on Fig. 1 two-flight screw after positive spin nut.

Fig. 5 is the sectional schematic diagram on Fig. 1 two-flight screw after derotation nut.

Fig. 6 is that Fig. 1 two-flight screw adds bolt head and forms schematic perspective view after bolt.

Fig. 7 is the schematic perspective view overlooked above one end of the second preferred embodiment of two-flight screw of the present invention and B-B sectional schematic diagram thereof.

Fig. 8 is the sectional schematic diagram on Fig. 7 two-flight screw after positive spin nut.

Fig. 9 is the sectional schematic diagram on Fig. 7 two-flight screw after derotation nut.

Figure 10 is that Fig. 7 two-flight screw adds bolt head and forms schematic perspective view after bolt.

Figure 11 is the schematic perspective view overlooked above one end of the 3rd preferred embodiment of two-flight screw of the present invention and C-C sectional schematic diagram thereof.

Figure 12 is the sectional schematic diagram on Figure 11 two-flight screw after positive spin nut.

Figure 13 is the sectional schematic diagram on Figure 11 two-flight screw after derotation nut.

Figure 14 is that Figure 11 two-flight screw adds bolt head and forms schematic perspective view after bolt.

Figure 15 is the schematic perspective view overlooked above one end of the 4th preferred embodiment of two-flight screw of the present invention and D-D sectional schematic diagram thereof.

Figure 16 is the schematic perspective view overlooked above one end of the 5th preferred embodiment of two-flight screw of the present invention and E-E sectional schematic diagram thereof.

Figure 17 is the sectional schematic diagram on Figure 16 two-flight screw after positive spin nut.

Figure 18 is the sectional schematic diagram on Figure 16 two-flight screw after derotation nut.

Figure 19 is the schematic perspective view overlooked above one end of two screw thread class screw-rod structure body one preferred embodiment of the present invention and F-F sectional schematic diagram thereof.

Embodiment

The specific embodiment provided below in conjunction with accompanying drawing elaborates to technological scheme of the present invention further.

Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5 are the first preferred embodiment of two-flight screw.

Two worm structure screw rods shown in Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5 comprise screw rod rod body 1, dextrorotation outside thread 2 and derotation outside thread 3, dextrorotation outside thread 2 is located at screw rod rod body 1 side, derotation outside thread 3 is located at screw rod rod body 1 opposite side, they do not interlock mutually, and dextrorotation outside thread 2 is contrary with the sense of rotation of derotation outside thread 3.

Dextrorotation outside thread 2 and derotation outside thread 3 are imperfect threads.

The use of this structure can coordinate the positive spin nut 4 matched or/and derotation nut 5, and positive spin nut 4 is represented by dotted lines in the diagram, and derotation nut 5 is represented by dotted lines in Figure 5.

Positive spin nut 4 internal thread 41 matches with dextrorotation outside thread 2 and is closely engaged, positive spin nut 4 can rotate along the path of dextrorotation outside thread 2, the each several part that derotation outside thread 3 is set to its whole outer rim 31 all has an opportunity to be close to the internal thread inner edge 42 of the positive spin nut 4 that screw rod screws, derotation outside thread 3 is not engaged with positive spin nut 4 internal thread 41, and now derotation outside thread 3 just plays the effect limiting positive spin nut 4 transverse shifting.

Derotation nut 5 internal thread 51 matches with derotation outside thread 3 and is closely engaged, derotation nut 5 can rotate along the path of derotation outside thread 3, the each several part that dextrorotation outside thread 2 is set to its whole outer rim 21 all has an opportunity to be close to the internal thread inner edge 52 of the derotation nut 5 that screw rod screws, dextrorotation outside thread 2 is not engaged with derotation nut inner thread 51, and now dextrorotation outside thread 2 just plays the effect of restriction derotation nut 5 transverse shifting.

The each several part of the whole outer rim 21 of above-mentioned dextrorotation outside thread 2 can share a cylndrical surface, and each several part of the whole outer rim 31 of above-mentioned derotation outside thread 3 can share another cylndrical surface.

Under the acting in conjunction of screw rod rod body 1, dextrorotation outside thread 2 and derotation outside thread 3, nut can only be longitudinally in rotary moving along screw rod, laterally can not rock, move.

Dextrorotation outside thread 2 is all set to the same triangle tooth form with the tooth form of derotation outside thread 3.

The tooth form of dextrorotation outside thread 2 and derotation outside thread 3, dental floss line number, pitch and dental floss radius are configured to the same all respectively.

Can use positive spin nut 4 and derotation nut 5 on this screw rod, when locking fits together mutually for positive spin nut 4 and derotation nut 5, positive spin nut 4 and derotation nut 5 restrict rotation mutually, even if under vibration environment, also not easily mutually unclamp simultaneously.

This screw rod also can as the common screw upper positive spin nut 4 or derotation nut 5, but having of not having is above-mentioned prevents loosening effect.

Fig. 6 is a specific embodiment of bolt.

Bolt shown in Fig. 6 is that the screw rod in Fig. 1 adds a bolt head 6.

Fig. 7, Fig. 8 and Fig. 9 are the second preferred embodiment of two-flight screw.

Shown in Fig. 7, Fig. 8 and Fig. 9 is two worm structure screw rods, and positive spin nut 4 is represented by dotted lines in fig. 8, and derotation nut 5 is represented by dotted lines in fig .9, and other composition is identical.

The difference of the present embodiment and Fig. 1 embodiment is: the dental floss line number of dextrorotation outside thread 2 and derotation outside thread 3, pitch and dental floss radius are configured to different all respectively.Other composition is identical.

Figure 10 is another specific embodiment of bolt.

Bolt shown in Figure 10 is that the screw rod in Fig. 7 adds a bolt head 6.

Figure 11, Figure 12 and Figure 13 are the 3rd preferred embodiment of two-flight screw.

Two worm structure screw rods shown in Figure 11, Figure 12 and Figure 13, positive spin nut 4 is represented by dotted lines in fig. 12, and derotation nut 5 is represented by dotted lines in fig. 13.

The difference of the present embodiment and Fig. 1 embodiment is: the dental floss line number of dextrorotation outside thread 2 and derotation outside thread 3, pitch and dental floss radius are also all arranged respectively to different; The tooth form of dextrorotation outside thread 2 is set to triangle tooth form, the tooth form of derotation outside thread 3 is set to trapezoidal tooth form, and namely the tooth form of dextrorotation outside thread 2 and derotation outside thread 3 arranges different.Other composition is identical.

Figure 14 is another specific embodiment of bolt.

Bolt shown in Figure 14 is that the screw rod in Figure 11 adds a bolt head 6.

Figure 15 is the 4th preferred embodiment of two-flight screw.

The difference of the two worm structure screw rod embodiment shown in Figure 15 and Fig. 1 embodiment is: the dental floss line number of dextrorotation outside thread 2 and derotation outside thread 3 and pitch are arranged respectively to different; The tooth form of dextrorotation outside thread 2 is set to triangle tooth form, the tooth form of derotation outside thread 3 is set to trapezoidal tooth form, and namely the tooth form of dextrorotation outside thread 2 and derotation outside thread 3 arranges different.Other composition is identical.

Figure 16, Figure 17 and Figure 18 are the 5th preferred embodiment of two-flight screw.

Two worm structure shown in Figure 16, Figure 17 with Figure 18 is identical with the structure shape that the screw rod shown in Fig. 1 is formed after upper and lower dextrorotation outside thread, derotation outside thread and screw rod rod body are respectively longitudinally by horizontal cutting.

This pair of worm structure screw rod comprises screw rod rod body 501, dextrorotation outside thread 502 and derotation outside thread 503, dextrorotation outside thread 502 is located at screw rod rod body 501 side, derotation outside thread 503 is located at screw rod rod body 501 opposite side, they do not interlock mutually, and dextrorotation outside thread 502 is contrary with the sense of rotation of derotation outside thread 503.

Dextrorotation outside thread 502 and derotation outside thread 503 are imperfect threads.

The use of this structure can coordinate the positive spin nut 504 matched or/and derotation nut 505, and positive spin nut 504 is represented by dotted lines in fig. 17, and derotation nut 505 is represented by dotted lines in figure 18.

Positive spin nut 504 internal thread 5041 matches with dextrorotation outside thread 502 and is closely engaged, positive spin nut 504 can rotate along the path of dextrorotation outside thread 502, the each several part that derotation outside thread 503 is set to the most peripheral outer rim 50311 of part equal radii on it all has an opportunity to be close to the internal thread inner edge 5042 of the positive spin nut 504 that screw rod screws, the outer rim 50312 that other radius of derotation outside thread 503 is less is not close to the internal thread inner edge 5042 of positive spin nut 504, derotation outside thread 503 is not engaged with positive spin nut 504 internal thread 5041, now derotation outside thread 503 just plays the effect limiting positive spin nut 504 transverse shifting.

Derotation nut 505 internal thread 5051 matches with derotation outside thread 503 and is closely engaged, derotation nut 505 can rotate along the path of derotation outside thread 503, the each several part that dextrorotation outside thread 502 is set to the most peripheral outer rim 50211 of part equal radii on it all has an opportunity to be close to the internal thread inner edge 5052 of the derotation nut 505 that screw rod screws, the less outer rim 50212 of other radius of dextrorotation outside thread 502 is not close to the internal thread inner edge 5052 of derotation nut 505, dextrorotation outside thread 502 is not engaged with derotation nut 505 internal thread 5051, now dextrorotation outside thread 502 just plays the effect of restriction derotation nut 505 transverse shifting.

The each several part of the most peripheral outer rim 50211 of described dextrorotation outside thread 502 part equal radii can share a cylndrical surface, and each several part of the most peripheral outer rim 50311 of described derotation outside thread 503 part equal radii can share another cylndrical surface.

Under the acting in conjunction of screw rod rod body 501, dextrorotation outside thread 502 and derotation outside thread 503, nut can only be longitudinally in rotary moving along screw rod, laterally can not rock, move.

Dextrorotation outside thread 502 is all set to the same triangle tooth form with the tooth form of derotation outside thread 503.

The tooth form of dextrorotation outside thread 502 and derotation outside thread 503, dental floss line number, pitch and dental floss radius are configured to the same all respectively.

Positive spin nut 504 and derotation nut 505 can be used on this screw rod simultaneously, when locking fits together mutually for positive spin nut 504 and derotation nut 505, positive spin nut 504 and derotation nut 505 restrict rotation mutually, even if under vibration environment, also not easily mutually unclamp.

This screw rod also can as the common screw upper positive spin nut 504 or derotation nut 505, but having of not having is above-mentioned prevents loosening effect.

Compared with the two-flight screw shown in Fig. 1, this two-flight screw more can save material, still can fastening positive spin nut or/and derotation nut, and identical effect can be reached.

Figure 19 is two screw thread class screw-rod structure body one preferred embodiments.

Shown in Figure 19 is a kind of two screw thread class screw-rod structure bodies for screwing thereon with internal thread object, the structure shape of the hollow formed after this pair of screw thread class screw-rod structure shape is cut in the middle part of rod body with the two-flight screw structure shown in Fig. 1 is identical, namely this pair of screw thread class screw-rod structure body has hollow portion 7, and this pair of screw thread class screw-rod structure body screws with the principle of internal thread object identical with the principle of the two-flight screw screw on nut shown in Fig. 1.This pair of screw thread class screw-rod structure body is the extension of the two-flight screw application shown in Fig. 1, as: because this pair of screw thread class screw-rod structure body is hollow, therefore can nozzle structure or bottleneck structure be used as.

Above-described specific embodiment is embodiments more of the present invention; not any pro forma restriction is done to the present invention; other variant and remodeling is also had under the prerequisite not exceeding the technological scheme described in claim; every employing analog structure of the present invention and change thereof, all should list protection scope of the present invention in.

Claims

1. a two-flight screw, comprises screw rod rod body (1), dextrorotation outside thread (2) and derotation outside thread (3), it is characterized in that:

Dextrorotation outside thread (2) is located at screw rod rod body (1) side, derotation outside thread (3) is located at screw rod rod body (1) opposite side, they do not interlock mutually, and dextrorotation outside thread (2) is contrary with the sense of rotation of derotation outside thread (3);

The use of this structure can coordinate the positive spin nut (4) matched or/and derotation nut (5);

Positive spin nut (4) internal thread (41) matches with dextrorotation outside thread (2) and is closely engaged, positive spin nut (4) can rotate along the path of dextrorotation outside thread (2), the each several part that derotation outside thread (3) is set to its whole outer rim (31) all has an opportunity to be close to the internal thread inner edge (42) of the positive spin nut (4) that screw rod screws, derotation outside thread (3) is not engaged with positive spin nut (4) internal thread (41), and now derotation outside thread (3) just plays the effect of restriction positive spin nut (4) transverse shifting;

Derotation nut (5) internal thread (51) matches with derotation outside thread (3) and is closely engaged, derotation nut (5) can rotate along the path of derotation outside thread (3), the each several part that dextrorotation outside thread (2) is set to its whole outer rim (21) all has an opportunity to be close to the internal thread inner edge (52) of the derotation nut (5) that screw rod screws, dextrorotation outside thread (2) is not engaged with derotation nut (5) internal thread (51), and now dextrorotation outside thread (2) just plays the effect of restriction derotation nut (5) transverse shifting;

The each several part of the whole outer rim (21) of above-mentioned dextrorotation outside thread (2) can share a cylndrical surface, and each several part of the whole outer rim (31) of above-mentioned derotation outside thread (3) can share another cylndrical surface;

Under the acting in conjunction of screw rod rod body (1), dextrorotation outside thread (2) and derotation outside thread (3), nut can only be longitudinally in rotary moving along screw rod, laterally can not rock, move;

Positive spin nut (4) and derotation nut (5) can be used on this screw rod simultaneously, when locking fits together mutually for positive spin nut (4) and derotation nut (5), positive spin nut (4) and derotation nut (5) restrict rotation mutually, even if under vibration environment, also not easily mutually unclamp;

This screw rod also can as the common screw upper positive spin nut (4) or derotation nut (5), but having of not having is above-mentioned prevents loosening effect.

2. two-flight screw according to claim 1, is characterized in that:

The tooth form of dextrorotation outside thread (2) or derotation outside thread (3) is not limit, and its tooth form can be set to triangle tooth form, trapezoidal tooth form, rectangle tooth form, arc tooth form or other various rational tooth forms;

The tooth form of dextrorotation outside thread (2) and derotation outside thread (3), dental floss line number, pitch and dental floss radius can be configured to the same or different respectively.

3. a two-flight screw, is characterized in that:

This two-flight screw structure shape is identical by the structure shape formed after reasonable cutting with the two-flight screw described in claim 1 or 2;

Above-mentioned cutting position can at dextrorotation outside thread (2) or/and derotation outside thread (3) be or/and screw rod rod body (1);

The use of this screw rod can coordinate the positive spin nut (504) matched or/and derotation nut (505);

Positive spin nut (504) internal thread (5041) matches with dextrorotation outside thread (502) and is closely engaged, positive spin nut (504) can rotate along the path of dextrorotation outside thread (502), the each several part that derotation outside thread (503) is set to the most peripheral outer rim (50311) of part equal radii on it all has an opportunity to be close to the internal thread inner edge (5042) of the positive spin nut (504) that screw rod screws, derotation outside thread (503) is not engaged with positive spin nut (504) internal thread (5041), now derotation outside thread (503) just plays the effect of restriction positive spin nut (504) transverse shifting,

Derotation nut (505) internal thread (5051) matches with derotation outside thread (503) and is closely engaged, derotation nut (505) can rotate along the path of derotation outside thread (503), the each several part that dextrorotation outside thread (502) is set to the most peripheral outer rim (50211) of part equal radii on it all has an opportunity to be close to the internal thread inner edge (5052) of the derotation nut (505) that screw rod screws, dextrorotation outside thread (502) is not engaged with derotation nut (505) internal thread (5051), now dextrorotation outside thread (502) just plays the effect of restriction derotation nut (505) transverse shifting,

The each several part of the most peripheral outer rim (50211) of described dextrorotation outside thread (502) part equal radii can share a cylndrical surface, and each several part of the most peripheral outer rim (50311) of described derotation outside thread (503) part equal radii can share another cylndrical surface;

Under the acting in conjunction of screw rod rod body (501), dextrorotation outside thread (502) and derotation outside thread (503), nut can only be longitudinally in rotary moving along screw rod, laterally can not rock, move;

Positive spin nut (504) and derotation nut (505) can be used on this screw rod simultaneously, when locking fits together mutually for positive spin nut (504) and derotation nut (505), positive spin nut (504) and derotation nut (505) restrict rotation mutually, even if under vibration environment, also not easily mutually unclamp;

This screw rod also can as the common screw upper positive spin nut (504) or derotation nut (505), but having of not having is above-mentioned prevents loosening effect.

4., for screwing the two screw thread class screw-rod structure bodies with internal thread object thereon, it is characterized in that:

The structure shape of the hollow formed after this pair of screw thread class screw-rod structure shape is cut in the middle part of rod body with the two-flight screw structure described in claims 1 to 3 any one is identical;

The principle that this pair of screw thread class screw-rod structure body screws with internal thread object is identical with the principle of screw on nut on above-mentioned two-flight screw.

5. a bolt, is characterized in that: application rights requires the two-flight screw described in 1 to 3 any one, and is provided with bolt head (6).