WO2009024093A1

WO2009024093A1 - A lockable and antirust bolt fastener

Info

Publication number: WO2009024093A1
Application number: PCT/CN2008/072084
Authority: WO
Inventors: Jilin Zhang; Yi Zhang
Original assignee: Beijing 3-D Spinal Orthopedics S & T Co. Ltd
Priority date: 2007-08-21
Filing date: 2008-08-21
Publication date: 2009-02-26

Abstract

A lockable and antirust bolt fastener comprises a bolt (1), an inner nut (2) and an outer screw head (3). Two segments of thread which are reversed in spiral direction are provided at the threaded end of the bolt. The inner nut contacts tightly with the outer screw head, and they engage with the two segments of thread respectively. The thread on the nut mated with the inner nut is inner thread or outer thread. A technique of locking an inner nut is employed in the invention, so the motion of the fastener restricted but it is easy to disassembled, moreover sealing protection for the thread is enhanced so as to avoid the thread from rusting.

Description

Locking rust bolt fastening

Technical field

The present invention relates to a bolt fastener, and more particularly to a locking rust preventive bolt fastener. Background technique

Bolts are industrial base parts and bolts are used on almost all machines. The existing bolts generally consist of a screw and a nut. The diameter of the screw is the same as that of the screw thread. The object fastened by the bolt is easy to loose under the action of vibration or other external force, and even the nut is detached. It is not uncommon for those who cause accidents. Since the anti-looseness of the existing bolt is achieved by the thread friction between the nut and the screw, the friction area is increased in order to prevent loosening. In the existing standard, it is generally necessary to use a spring washer for anti-looseness, and at the same time, after tightening with two nuts, the screw should also expose 2 to 3 turns of the thread, which wastes material and is not beautiful. Due to the obvious gap between the nut and the screw, the thread between the iron or copper material will rust after a long time, causing trouble for removal. In order to prevent loosening, some people use adhesive on the fastening bolts, which will cause inconvenience to the disassembly. Summary of the invention

In order to overcome the drawbacks of prior art fasteners that are prone to looseness and rust, the present invention provides a locking rust-proof bolt fastener.

In order to achieve the above object, the technical solution adopted by the present invention is: a locking rustproof bolt fastener, including a screw and an inner nut, which are special in that: an external screw head is also included. The threaded end of the screw is provided with two threads of opposite rotation directions, the inner nut is in close contact with the outer screw head, the contact surface is a smooth surface, and the inner nut and the outer screw head are respectively matched with the two threads.

The shape of the end surface of the inner nut contacting the outer screw head is a slope having a certain degree of twist.

The angle of inclination of the contact surface between the inner nut and the outer screw head is 30° to 50°.

The contact surface of the inner nut and the outer screw head is coated with organic oil to increase the sealing property of the screw thread, avoid contact with air and water and rust, and is easy to disassemble.

The threaded end of the screw is provided with a screw hole, the two threads on the screw are respectively an external thread and an internal thread, the internal thread is disposed in the screw hole of the thread end, and the external screw is a screw; the inner nut and the external thread are Cooperating, the screw cooperates with the internal thread; the depth of the screw hole is smaller than the thickness of the inner nut.

The two threads on the screw are externally threaded, the connection is stepped, and the diameter of one of the external threads near the end of the screw is smaller than the diameter of the other external thread; the inner nut is matched with the external thread with a large diameter, the external screw The head is a nut that cooperates with an external thread having a small diameter; the inner diameter of the inner nut is larger than the outer diameter of the outer diameter of the small diameter.

The advantages of the present invention over the prior art are as follows:

1. In the present invention, there are two segments of oppositely rotating threads, and the outer screw head locks the inner nut to make the bolt more and more tight under the action of vibration or other external force, and is not easy to loose.

2. In the present invention, the shape design of the contact surface of the inner nut and the outer screw head increases the contact area, enhances the anti-loose ability, reduces the original material under the condition of achieving the same stress, and reduces the production cost.

3. In the invention, the inner nut and the outer screw head are closely matched, and the smooth contact surface is added with organic oil, thereby increasing the sealing protection of the thread, so that the thread is not in contact with air or water, preventing the growth. Rust is also easy to disassemble; at the same time, the smooth surface is easy to process and easy to use.

4. The inner nut of the present invention is a stressed body, and its thickness and cross-sectional area can be calculated by using appropriate specifications to reduce unsafe factors and save raw materials.

5. The external screw head of the invention has the functions of sealing the thread with the inner nut, preventing the thread from rusting and preventing the inner nut from loosening, and also has the auxiliary force acting.

6. In the present invention, the depth of the screw hole is smaller than the thickness of the inner nut to prevent the shear stress of the fastened object from being lowered due to the excessively large screw hole. DRAWINGS

Figure 1 is a schematic view of the overall structure of the present invention.

2 is a schematic structural view of another embodiment of the present invention.

Reference mark:

1 screw, 2 - inner nut, 3 nut, 4 screws, 5 - screw holes. detailed description

The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to FIG. 1 , a locking rust-proof bolt fastener includes a screw 1 and an inner nut 2 , and further includes a nut 3 . The threaded end of the screw is provided with two external threads with opposite rotation directions, and the joint is The stepped shape has a diameter of a portion of the external thread near the end of the screw smaller than the diameter of the other portion of the external thread; the inner nut 2 cooperates with the external thread having a large diameter, and the nut 3 cooperates with the external thread having a small diameter. The inner nut 2 is in close contact with the nut 3, and the end face of the contact is shaped The bevel of a certain degree of inclination, the inclination angle of the inclined surface is 30° ~ 50°, the purpose is to save material and reduce weight without reducing the contact area between the inner nut 2 and the nut 3 and the screw thread. The contact surface of the inner nut 2 and the nut 3 is a smooth surface, and is coated with organic oil to increase the sealing property of the screw thread, avoid contact with air and water, and rust, and is easy to disassemble.

In use, the screw 1 is inserted into the hole of the object to be fastened, the fastened object is fastened with the inner nut 2, and the oppositely screwed nut 3 is screwed to be tightly coupled with the inner nut 2. If the screw 1 is slightly longer and the nut 3 and the inner nut 2 are not tightly coupled, a washer may be added to the unthreaded end of the screw; if the screw 1 is slightly shorter, the inner nut 2 and the nut 3 may be inserted into a few wires. When the tightened object is to be loosened, the inner nut 2 must be reversed. Since the nut 3 and the inner nut 2 are oppositely rotated, the rotation of the inner nut 2 is prevented, and self-locking is achieved, so that it is firm and reliable, and can prevent looseness.

Referring to FIG. 2, FIG. 2 is another embodiment of the present invention, including a screw 1, an inner nut 2, and a screw 4. The screw end of the screw 1 is provided with a screw hole 5, and the threaded end of the screw 1 is provided with two segments. The threads of opposite rotation directions are respectively an external thread and an internal thread, and the internal thread is disposed in the screw hole 5 of the thread end; the inner nut 2 is matched with the external thread, and the screw 4 is matched with the internal thread. The inner nut 2 is in close contact with the screw 4, and the end face of the contact is shaped as a bevel having a certain degree of inclination, and the inclination angle of the inclined surface is 30° to 50°. The contact surface of the inner nut 2 and the screw 4 is a smooth surface and coated with organic oil. The depth of the screw hole 5 described above is smaller than the thickness of the inner nut 2.

In use, the screw 1 is inserted into the hole of the fastened object, the fastened object is fastened with the inner nut 2, and the oppositely screwed 4 is screwed to be tightly coupled with the inner nut 2. When the fastened object is to be loosened, the inner nut 2 must be reversed due to the screw of the screw 4 and the inner nut 2. The rotation of the thread is reversed, which prevents the rotation of the inner nut 2 and realizes self-locking, so it is firm and reliable, and can prevent looseness.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Those skilled in the art should be included in the scope of the present invention.

Claims

Claim

A locking rust-proof bolt fastener, comprising a screw and an inner nut, characterized in that: further comprising an outer screw head, wherein the threaded end of the screw is provided with two threads of opposite rotation directions, an inner nut and an outer screw The head is in close contact, the contact surface is smooth, and the inner nut and the outer screw head are respectively matched with the two threads.

2. A locking rust-proof bolt fastener according to claim 1, wherein: the end surface of the inner nut in contact with the outer screw head has a slope having a certain degree of twist.

3. A locking rust-proof bolt fastener according to claim 2, wherein: the angle of inclination of the contact surface between the inner nut and the outer screw head is 30° to 50°.

4. A locking rust-proof bolt fastener according to claim 2, wherein: the contact surface of the inner nut and the outer screw is coated with organic oil.

5 . The locking rustproof bolt fastener according to claim 1 , wherein: the threaded end of the screw is provided with a screw hole, and the two threads on the screw are respectively an external thread and an internal thread The internal thread is disposed in the screw hole of the threaded end, and the external screw is a screw; the inner nut is matched with the external thread, and the screw is matched with the internal thread; the depth of the screw hole is smaller than the thickness of the inner nut.

6. A locking rust-proof bolt fastener according to claim 1, wherein: the two threads on the screw are externally threaded, and the joint is stepped, adjacent to a section of the screw end. The outer thread diameter is smaller than the diameter of the other outer thread; the inner nut is matched with the outer diameter of the outer diameter, the outer screw head is a nut, and the inner diameter of the inner nut is matched; the inner diameter of the inner nut is larger than the diameter The outer diameter of the external thread.