WO2002057639A1

WO2002057639A1 - A composite screw structure having elliptical cross-section of minor diameter thereof

Info

Publication number: WO2002057639A1
Application number: PCT/IB2001/000552
Authority: WO
Inventors: Zong Cai Tang; Wo Ho To; Yicheng Zhou; Chi Ki Cheung
Original assignee: Zong Cai Tang; Wo Ho To; Yicheng Zhou; Chi Ki Cheung
Priority date: 2001-01-19
Filing date: 2001-04-03
Publication date: 2002-07-25
Also published as: CN1317651A

Abstract

A composite screw structure is formed of a left-hand thread and a right-hand thread, in which said two threads of opposite hand are arranged uniformly and their roots cross each other; wherein the cross-section of minor diameter of said composite screw structure is elliptical.

Description

Elliptical compound thread structure with small diameter

Technical field

The invention relates to a composite thread structure. Background technique

Threaded joints are widely used in fastener joints, but they have the problem of loosening. At present, a composite thread structure is adopted. A composite thread is a discontinuous and variable cross-section thread. This thread is composed of two left- and right-handed helixes with different rotation directions. The bottoms of the thread teeth cross each other. Compound threads can be used with both ordinary left-handed threads and ordinary right-handed threads. Compound threads are widely used, especially for anti-loosening applications of fasteners. Use two turn nuts with different rotation directions, that is, the fastening nut on the support surface of the workpiece and the lock nut on the non-support surface to prevent loosening. However, due to improper tightening or other reasons, the pre-tightening force of the lock nut is too small. In this case, the lock nut will be loosened first, resulting in loosening of the composite thread. Disclosure of invention

An object of the present invention is to provide an effective torque-type composite screw structure capable of forming friction force between the screw pairs in the lateral direction.

The present invention is realized by providing an effective moment type composite thread structure with a small diameter of an ellipse.

Because the small diameter of the effective torque type compound thread is oval, and the ordinary thread is a cylindrical thread, when the effective torque type compound thread is matched with the ordinary thread, the ordinary thread and the effective moment type compound thread will be elastically deformed. The effective torque-type composite threads are tightened tightly, and the threads are compressed laterally, and the friction between the thread pairs is greatly increased, thereby greatly improving the anti-loosening effect. The tube of the drawings is to be explained

FIG. 1 is a top view of an effective torque type composite thread structure of the present invention;

FIG. 2 is a front view of an effective moment type composite thread structure of the present invention; FIG.

FIG. 3 is a side view of an effective torque type composite thread structure of the present invention. The best way to implement the invention

FIG. 1 is a plan view of an effective torque type composite thread structure of the present invention, that is, a radial view. In FIG. 1, the small-diameter short axis L1 and the small-diameter long axis L2 of the effective moment type composite thread structure are not equal, and the small diameter of the effective moment type composite thread structure is oval. 1 is the outer contour of the effective torque type compound thread.

The difference between the effective torque-type composite thread structure and the composite thread structure of the present invention is that the turning track of the composite torque thread is round, while the turning track of the effective torque-type composite thread is oval, that is, the small diameter of the elliptical thread can It is processed by known techniques such as a well-known CNC lathe, a CNC contour lathe, and the like.

It can also be seen from Fig. 2 and Fig. 3 that the lengths of the small-diameter short axis L1 and the small-diameter long axis L2 of the effective torque type composite thread are not equal. Preferably, the difference between the length of the long axis and the short axis is not greater than the tooth height of the thread. Industrial applicability

There is a lateral compression thread between the effective torque type compound thread and the lock nut, and the friction between the thread pair is greatly increased, which can effectively prevent the nut from loosening. Can be widely used in the connection of threaded fasteners. The invention has novel structure, clean tube, wide application, and very good anti-loose effect.

Claims

Profit requirements

1. An effective torque type composite thread structure. The thread is compounded by two types of spirals, left and right, and the two spirals are evenly distributed. The threads are formed to intersect with each other, and are characterized by the effective torque. The small diameter of the compound thread is oval.

2. The effective torque-type composite thread structure as described in Tweet Requirement 1,

It is characterized in that the elliptical minor diameter is preferably such that the difference between the long axis and the short axis is not greater than the tooth height of the spiral.