RU2264563C2 - Conical thread - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: conical thread comprises turns made of parallelograms and is cut on the conical surfaces of screw and nut. The sum of the acute angle of the parallelogram and half angle at the top of the cones that engage the conical surfaces of the screw and nut is 90°.

EFFECT: enhanced reliability.

4 dwg

Description

The invention relates to equipment for general engineering.

A known design with emergency locking devices made in the form of elements with threaded conical working surfaces [1]. However, this design does not indicate which thread profile is used.

A known design of a metric tapered thread designed to connect cylindrical parts [2]. The internal and external threads are wound on each other for a certain number of revolutions, moving relative to each other in the axial direction for a considerable distance. Since the screw and nut are previously disconnected, the screw is twisted relative to the nut. The initial is the relative position of the screw and nut, in which the conical surfaces of the vertices of the screw and nut are in contact with each other.

The disadvantage of this design is:

1) when the screw rotates relative to the nut in one direction, the turns of the nut will slip relative to the turns of the screw, because in a triangular profile the width of the vertices of the turns is much less than the distance between the turns;

2) when rotating in the opposite direction, it is necessary to make a sufficiently large number of revolutions until the screw completely locks in relation to the nut.

The objective of the invention is: to ensure the effectiveness of the interaction of the contacting threaded elements, i.e. free rotation of the screw relative to the nut on the conical surfaces without slipping when rotating in one direction, and quick locking of the screw relative to the nut when rotating in the opposite direction.

This problem is solved by the fact that in a tapered thread, the profile of the shape of the turns of which is a parallelogram located on the conical surfaces of the screw and nut, the sum of the acute angle of the parallelogram and half the angle at the apex of the cones of the contacting conical surfaces of the screw and nut is 90 °.

The invention is illustrated by drawings, in which Fig. 1 shows a threaded connection in working condition, in Fig. 2 a threaded connection in a locked state, in Fig. 3 - element I of Fig. 1, in Fig. 4 - element II of Fig. 2.

The device consists of screw 1 and nut 2. On the conical surfaces of screw 1 and nut 2, threads are cut having a parallelogram shape in the profile. The acute angle of this parallelogram in total with a half angle at the apex of the contacting conical surfaces of the screw and nut is 90 °. The angle at the apex is the angle α in Fig. 1.

Cone thread can be right and left, single and multi-thread.

The device operates as follows.

When the screw 1 rotates relative to the nut 2, the threads of the screw and the nut disengage relative to each other, and the screw 1 rotates freely relative to the nut 2 along the contact conical surfaces (“cone in cone”).

When the screw 1 (or nut 2) is rotated in the opposite direction, all turns of screw 1 and nut 2 simultaneously mesh with each other and stop the movement. The contact of the screw 1 and nut 2 occurs on two surfaces: conical and spiral. Due to the ratio of the parallelogram angles to the taper angle of the surfaces, the twisting and untwisting of the thread occurs very quickly and effortlessly.

Sources of information

1. A.S. USSR No. 1761640, 65 G 23/00.

2. GOST 25229-82. Conical metric thread.

Claims (1)

Cone thread, the profile of the shape of the turns of which is a parallelogram cut on the conical surfaces of the screw and nut, characterized in that the sum of the acute angle of the parallelogram and half the angle at the apex of the cones of the contacting conical surfaces of the screw and nut is 90 °.

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