EP4015733A1

EP4015733A1 - Coupler

Info

Publication number: EP4015733A1
Application number: EP20215469.6A
Authority: EP
Inventors: Claudio Hasler; Thomas Foser
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2022-06-22

Abstract

A coupler for coupling a first elongated element having a first end portion to a second elongated element having a second end portion is disclosed. The coupler comprises a first coupling element and a second coupling element, wherein the first coupling element comprises a first attachment portion for attaching the first coupling element to the first end portion, and a screw portion having a male thread, and wherein the second coupling element comprises a second attachment portion for attaching the second coupling element to the second end portion, and a nut portion having a female thread fitting on the male thread, thereby fastening the first coupling element to the second coupling element. The male thread comprises two or more individual threads.

Description

TECHNICAL FIELD

Described herein is a coupler for coupling a first elongated element having a first end portion to a second elongated element having a second end portion, and associated parts thereof. The coupler may include a thread in order to achieve coupling.

BACKGROUND ART

In many applications, there is the need to join to, or couple with, elements. One such application is reinforced concrete where reinforcing bars that are placed into the concrete are typically supplied in discrete lengths. There are many locations where the reinforcing bar must continue for a length longer than the discrete length supplied, and it becomes necessary to join multiple lengths together. One means of achieving this is to use a coupling device to join the bars together in an axial means.
The above application and discussion below refer to reinforcing bars in concrete as a potential application for a coupling method, however, it should be appreciated that many other applications require coupling of elements in an axial manner, such as steel light columns, scaffolding elements, pipes, cables, and so on and reference to reinforcing bars should not be seen as limiting.
One constraint with coupling system design relates to axial stress. Once fabricated, the reinforced concrete may be subjected to some applied loading which will place the coupled reinforcing bar into a state of axial stress. For example, under loading imposed by a large earthquake, a concrete element may become cracked and deformed. This may require the coupled reinforcing bar to stretch to a high level of plastic strain. The coupling device will then be required to have sufficient capacity to resist the full range of likely stresses and strains that may be imparted when in use.
In some situations, a reinforcing bar needs to be coupled to another reinforcing bar which is already cast in, for example if a concrete element is to be attached to a pre-existing concrete element. It is known to provide the reinforcing bar in the pre-existing wall element with a coupling element having a female thread, and to provide a reinforcing bar with a male thread fitting to the female thread. The reinforcing bar with the male thread may then be screwed into the female thread which may be rather exhausting due to the length and weight of the reinforcing bar which needs to be turned as a whole.
Offering an alternative design that addresses some or all of the above constraints or at least offers the public a choice may be useful. Further aspects and advantages of the coupler method and associated parts thereof will become apparent from the ensuing description that is given by way of example only.

SUMMARY

The above constraints are addressed by a coupler for coupling a first elongated element having a first end portion to a second elongated element having a second end portion, comprising a first coupling element and a second coupling element, wherein the first coupling element comprises a first attachment portion for attaching the first coupling element to the first end portion, and a screw portion having a male thread, and wherein the second coupling element comprises a second attachment portion for attaching the second coupling element to the second end portion, and a nut portion having a female thread fitting on the male thread, thereby fastening the first coupling element to the second coupling element, wherein the male thread comprises two or more individual threads. In this way, the first elongated element, once attached to the first attachment portion, may be screwed into the nut portion with fewer turns as compared to a system providing a single thread only, but keeping the same number of thread leads for load transmission.
In a preferred embodiment, the screw portion tapers towards the second coupling element. By fitting on the male thread, the female thread then tapers away from the first coupling element. Such a configuration may further reduce a duration necessary for screwing the first elongated element into the nut portion. A frustoconical shape of the screw portion is preferred, even more if the frustoconical shape of the screw portion has a cone angle a between 10° and 20°.
In another preferred embodiment, the male thread and the female thread are self-locking. In this way, time-consuming steps of checking a proper connection between the first coupling element and the second coupling element may be reduced.
In another preferred embodiment, the first attachment portion comprises a first wall enclosing a first receptacle for receiving the first end portion. In an even more preferred embodiment, the first receptacle has a first receiving diameter and the male thread has a male thread diameter greater than the first receiving diameter. This may avoid creating a weak portion by reducing the diameter of load-transmitting parts. In a likewise preferred embodiment, the first coupling element comprises a first load-transmission element transmitting mechanical load from the first elongate element to the first coupling element. In an even more preferred embodiment, the first load-transmission element comprises at least one of a stud, a nail and a screw.
In another preferred embodiment, the second attachment portion comprises a second wall enclosing a second receptacle for receiving the second end portion. In an even more preferred embodiment, the second receptacle has a second receiving diameter and the female thread has a female thread diameter greater than the second receiving diameter. In a likewise preferred embodiment, the second coupling element comprises a second load-transmission element transmitting mechanical load from the second elongate element to the second coupling element. In an even more preferred embodiment, the second load-transmission element comprises at least one of a stud, a nail and a screw.
In another preferred embodiment, at least one of the first elongated element, the second elongated element, the first coupling element, the second coupling element, the first load-transmission element, and the second load-transmission element comprises a metallic material, or an alloy, or steel. In another preferred embodiment, the first and second elongated elements each comprises a reinforcement bar.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects and advantages of the coupler, associated parts and a method of use thereof will become apparent from the ensuing description that is given by way of example only and with reference to the accompanying drawings in which:

Fig. 1: illustrates a coupler in a perspective view,
Fig. 2: illustrates a thread portion in a side view, and
Fig. 3: illustrates a nut portion in a cross-sectional side-view.

DETAILED DESCRIPTION

Figs. 1 shows a coupler 100 for coupling a first elongated element 101 formed as a reinforcement bar and having a first end portion 102 to a second elongated element 103 likewise formed as a reinforcement bar and having a second end portion 104. The coupler 100 comprises a first coupling element 110 and a second coupling element 140. The first coupling element 110 comprises a first attachment portion 120 and a screw portion 130. The first attachment portion 120 comprises a first wall 121 enclosing a first receptacle 122 in which the first end portion 102 is received. For attaching the first coupling element 110 to the first end portion 102, the first coupling element 110 comprises a plurality of first load-transmission elements 125 formed as nails which are driven into a gap between the first end portion 102 and the first wall 121 for transmitting mechanical load from the first elongate element 101 to the first coupling element 110. Likewise, the second coupling element 140 comprises a second attachment portion 150 and a nut portion 160. The second attachment portion 150 comprises a second wall 151 enclosing a second receptacle (not shown) in which the second end portion 104 is received. For attaching the second coupling element 140 to the second end portion 104, the second coupling element 140 comprises a plurality of second load-transmission elements 155 formed as nails which are driven into a gap between the second end portion 104 and the second wall 151 for transmitting mechanical load from the second elongate element 103 to the second coupling element 140. In non-shown embodiments, some or all of the first and second load-transmission elements are formed as studs or screws and are driven tangentially or radially onto the first end portion.
The screw portion 130 comprises a male thread 170 tapering towards the second coupling element 140. The nut portion 160 comprises a female thread 180 tapering away from the first coupling element 110 and fitting on the male thread 170 in a self-locking manner. In this way, easy fastening the first coupling element 110 to the second coupling element 140 is possible by screwing the screw portion 130 into the nut portion 160. The male thread 170 has a male thread diameter which is greater than a first receiving diameter of the first receptacle and thus the first elongated element 101. Likewise, the female thread 180 has a female thread diameter which is greater than a second receiving diameter of the second receptacle and thus the second elongated element 103. In this way, the screw portion 130 and the nut portion 160 are avoided to be the weakest portions of the overall connection or reinforcement between the first and second elongated elements 101, 103 when the screw portion 130 is screwed to the nut portion 160.
The first elongated element 101, the second elongated element 103, the first coupling element 110, the second coupling element 140, the first load-transmission elements 125, and the second load-transmission elements 155 are made of an alloy, such as steel. In a first step during an exemplary use of the coupler 100, the second coupling element 140 may be attached to the second elongate element 103 by inserting the second end portion 104 into the second receptacle 152 and driving the plurality of second load-transmission elements 155 through the second wall 151 onto the second end portion 104. In a subsequent step, the second elongate element 103 and the second coupling element 140 are poured into concrete such that the nut portion 160 is accessible. In a subsequent step, the first coupling element 110 is attached to the first elongate element 101 by inserting the first end portion 102 into the first receptacle 122 and driving the plurality of first load-transmission elements 125 through the first wall 121 onto the first end portion 102. In a subsequent step, the screw portion 130 is screwed into the nut portion 160 to fasten the first elongate element 101 to the second elongate element 103. In a final step, the first elongate element 101 and the first coupling element 110 may be poured into concrete, too.
Fig. 2 shows the screw portion 130 in a side view. The male thread 170 comprises a first individual male thread 171 and a second individual male thread 172. Each of the first and second individual male threads 171, 172 have a greater thread pitch as compared to a screw having one single thread only. In this way, screwing the screw portion 130 into the nut portion 160 may be accelerated. The screw portion 130 has a frustoconical shape with a flat front face 131 and a cone angle of 15°.
Fig. 3 shows the nut portion 160 and part of the attachment portion 150 in a cross-sectional side view. The female thread 180 comprises a first individual female thread 181 and a second individual female thread 182. Each of the first and second individual female threads 181, 182 fit the first and second individual male threads 171, 172. Accordingly, the nut portion 160 has a frustoconical shape with the same cone angle a of 15°. The female thread 180 has a female thread diameter d which is greater than a second receiving diameter of the second receptacle 152 and thus the second elongated element 103.
The foregoing description of exemplary embodiments of the invention have been presented for purposes of illustration and of description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The functionality described may be distributed among modules that differ in number and distribution of functionality from those described herein. Additionally, the order of execution of the functions may be changed depending on the embodiment. The embodiments were chosen and described in order to explain the principles of the invention and as practical applications of the invention to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims

A coupler for coupling a first elongated element having a first end portion to a second elongated element having a second end portion, comprising a first coupling element and a second coupling element, wherein the first coupling element comprises a first attachment portion for attaching the first coupling element to the first end portion, and a screw portion having a male thread, and wherein the second coupling element comprises a second attachment portion for attaching the second coupling element to the second end portion, and a nut portion having a female thread fitting on the male thread, thereby fastening the first coupling element to the second coupling element, wherein the male thread comprises two or more individual threads.
The coupler according to claim 1, wherein the screw portion tapers towards the second coupling element.
The coupler according to claim 2, wherein the screw portion has a frustoconical shape.
The coupler according to claim 3, wherein the frustoconical shape of the screw portion has a cone angle a between 10° and 20°.
The coupler according to any of the preceding claims, wherein the male thread and the female thread are self-locking.
The coupler according to any of the preceding claims, wherein the first attachment portion comprises a first wall enclosing a first receptacle for receiving the first end portion.
The coupler according to claim 6, wherein the first receptacle has a first receiving diameter and the male thread has a male thread diameter greater than the first receiving diameter.
The coupler according to any one of claims 6 and 7, wherein the first coupling element comprises a first load-transmission element transmitting mechanical load from the first elongate element to the first coupling element.
The coupler according to claim 8, wherein the first load-transmission element comprises at least one of a stud, a nail and a screw.
The coupler according to any of the preceding claims, wherein the second attachment portion comprises a second wall enclosing a second receptacle for receiving the second end portion.
The coupler according to claim 10, wherein the second receptacle has a second receiving diameter and the female thread has a female thread diameter greater than the second receiving diameter.
The coupler according to any one of claims 10 and 11, wherein the second coupling element comprises a second load-transmission element transmitting mechanical load from the second elongate element to the second coupling element.
The coupler according to claim 12, wherein the second load-transmission element comprises at least one of a stud, a nail and a screw.
The coupler according to any of the preceding claims, wherein at least one of the first elongated element, the second elongated element, the first coupling element, the second coupling element, the first load-transmission element, and the second load-transmission element comprises a metallic material, or an alloy, or steel.
The coupler according to any of the preceding claims, wherein the first and second elongated elements each comprises a reinforcement bar.