SK107092A3 - Sleeve for connecting of bars - Google Patents

Abstract

To prevent damage in making a sleeve joint - primarily for reinforcing rods - and improve the static and dynamic bearing strength of the joint, the sleeve (1) has a gradually rising profile in the end regions (3) for the jointing of metal rods (5/1, 5/2) with conical thread cores (7) in the thread end regions (6).

Description

The invention relates to a threaded sleeve connection, in particular reinforcing rods, made by screwing two metal rods provided at their ends with a conical thread projecting into the threaded end portions into a metal sleeve provided with a corresponding internal thread.

BACKGROUND OF THE INVENTION

The sleeves of the known sleeve connections are designed as cylindrical or with hexagonal cross-section along their entire length with a fixed contour.

There are also known sleeves for connecting clamping bars which are provided with conical tapered edges at their ends. These chamfered edges in the also conically expanded casing tubes, adapted to the sleeves in the shape, are intended to allow as even a flow of the compressed mortar as possible.

DE-PS 17 84 382 discloses a sleeve connection with a thread of the reinforcing bars, in which the ends of the reinforcing bars are threaded, conically extending into the threaded end portion. The ends of the reinforcing bars are screwed into the sleeve, which, however, is not tapered at its end portions, with great effort. The conical threaded end portions of the reinforcing bars are screwed into the sleeve according to the torque to a different length. As a rule, the remainder of the thread of the outer sleeve remains. When screwing a non-attenuated sleeve onto the thread of the rod, the thread of the sleeve, in particular, has its short end portion inserted into a relatively small piece of thread on the conical protruding rod core and deforms this portion. The transmission of forces from the rod to the sleeve occurs in this short, deformed part, in particular, as long as this part deforms and becomes further supporting parts of the thread. This deformation process causes undesired slip which must not exceed a certain permissible level.

SUMMARY OF THE INVENTION It is an object of the present invention to provide such a connection with a threaded sleeve which does not slip and does not increase the static and dynamic support forces of the rod connection.

SUMMARY OF THE INVENTION

This object is achieved by a threaded sleeve connection, in particular reinforcing rods, made by screwing two metal rods provided at their ends with a conical thread projecting into the threaded end portions, into a metal sleeve provided with a corresponding female thread, according to the invention. have an outer contour progressively rising to the center of the sleeve.

The progressively rising sleeve contour, adapted to transmit forces from the rod to the sleeve and corresponding to the progressive increase in the sleeve cross-section, causes the sleeve to become increasingly deformable towards its ends and elongates at these ends when screwed to a certain torque. As a result, the entire conical projecting threaded portion of each of the rods to be coupled is force-adjusted, substantially preventing slippage and achieving a higher static and dynamic load-bearing capacity of the sleeve connection.

The forming curve of the contour of the sleeve rising progressively outward from the end of the sleeve may be, for example, a parabola, a hyperbola, an exponential, a sinusoid or even a polygon.

According to a preferred embodiment, the sleeve is provided with bevelled edges at both ends of its hole. These bevelled edges prevent the occurrence of stress peaks in the connected rods, which would otherwise arise at the inner ends of the sharp-edged sleeve and reduce the fatigue limit at oscillating stress. The chamfered edges preferably have a straight or curved contour which gradually increases from the end of the sleeve.

According to a further embodiment of the invention, the sleeve has a length so as to prevent radial tearing of its ends by accidentally exceeding the torque causing the rod ends to be screwed into the sleeve such that a slight gap remains between the rod ends of the rod ends. This gap is of such a size that, if the permissible torque is exceeded when the sleeve is screwed in, both ends of the rods come into contact. This prevents the ends of the rods from penetrating deeply into the sleeve.

An overview of the figure in the drawings

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the accompanying drawing, in which: FIG. 1 shows a longitudinal section through a sleeve according to the invention, and FIG. 2 shows a longitudinal cross-sectional view of the connection with the threaded sleeve according to the invention, whereby the sleeve is deformed after screwing in the ends of the rods.

DETAILED DESCRIPTION OF THE INVENTION

The sleeve 2 according to the invention, provided with an internal thread 2, has an outer contour at its two end portions 2, which progressively increases towards the center of the sleeve 1. The ends of the sleeve 2 are provided with bevelled edges 2 inside.

Fig. 2 shows the assembled collar connection. The ends 5.1 and 5.2 of the rods 5 with end threads 6 and the tapered projecting threaded end portions T1 are screwed into the sleeve. In this case, the end portions 3 of the sleeve 1, which are weakened with respect to the cross-section of the center part of the sleeve 1, have a contour rising progressively towards the center of the sleeve 7, and have been deformed and widened along the thread profile 6 of the connecting rods 5.

It remains between the end faces 2 of the ends of the bars 5 when a certain tightening torque is applied, when the ends of the bars 5 are screwed into the sleeve 10 of the spreader 10, the width of which may be zero when the specified torque is exceeded. The width of the gap 10 limits the expansion of the open ends of the sleeve 7 at an impermissibly high torque to screw the connecting rods 5 to measure to prevent the sleeve 11 from tearing.

Claims (3)

Threaded sleeve connection, in particular reinforcing rods, made by screwing two metal rods (5) provided at their ends (5.1, 5.2) with a thread (6) conically extending in the threaded end portion, into a metal sleeve (1) provided with a corresponding internal thread (2), characterized in that the two end portions (3) of the sleeve (1) have an outer contour progressively rising towards the center of the sleeve (1). Threaded sleeve connection according to claim 1, characterized in that the sleeve (1) is provided at its ends with a bevelled edge (4). Threaded sleeve connection according to claim 1 or 2, characterized in that the length of the sleeve (1) and the length of the end threads (6) of the rods (5) are adapted to each other such that when a certain torque is generated after screwing the rods (5) until the end of the sleeve (1) on the end (8) of the end thread (7) of the rod (5), there remains a gap (10) between the end faces (9) of the rod end (5). exceeding this torque when screwing the ends of the rods (5) into the sleeve (1) reduces the gap (10) to zero, so that the lengthening and widening of the ends of the sleeve (1) caused by the maximum screwing depth of the rods (5) the material of the sleeve (1).