Device for connecting bars end-to-end

Abstract

A device for connecting bars end-to-end includes a hollow body having an internal cavity with at least one bar insertion opening and a longitudinal axis extending through the at least one insertion opening, and a plurality of radially adjustable clamping elements. The device further includes at least one locking element movably arranged inside the hollow body. The internal cavity of the hollow body has at least one slope inclined relative to the longitudinal axis of the hollow body. The at least one locking element has an inclined face that matches the profile of the at least one slope and a gripping face with at least one protrusion.

Description

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS[0001]Not applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT[0003]Not applicable.REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC[0004]Not applicable.BACKGROUND OF THE INVENTION[0005]1. Field of the Invention[0006]The present invention relates to a device for connecting two bars in an end-to-end relationship. The device has a particular application in coupling the ends of reinforcing bars used in structural concrete.[0007]2. Description of Related Art[0008]Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.[0009]In the art of joining two bars end-to-end in order to extend their continuity, it is known to use a tubular sleeve that receives the end portion of each bar, the sleeve having radially-oriented elements that are forced into the material of the bars in order to lock them. According to one device as disclosed in U.S. Pat. No. 5...

AI Technical Summary

Benefits of technology

[0015]Compared to many of the existing systems to connect two bars end-to-end, such as threading or forging the bar ends, the device of the present invention presents the advantage of not needing any preparation of the bar end. This means that it is not necessary to either transport the bars to a workshop where their ends can be prepared, or transport to the location of the bars the machinery needed to prepare their ends. This system was indeed developed with the aim of enabling a site assembly, with only a pneumatic or electric wrench needed to torque the screws. A site assembly is a great benefit in some industries such as the construction or the oil industry. It is also a great benefit in large countries where transport of bars is an issue, due to long distances.

[0016]It is an object of the present invention to provide a device for connecting bars in an end-to-end relationship that upholds the benefit of site assembly, in addition to new benefits in terms of increased reliability, improved safety to the structure, and better tensile and load bearing performance.

[0017]The present invention also reduces bulkiness compared to the prior art systems. The improved size of the device improves safety for the installer and the individuals working around the device at the work or construction site.

Problems solved by technology

The prior art systems have drawbacks.

First of all, the pneumatic and electric tools that are commonly available on the market are of limited capacity, which means that it is not possible to increase the size or strength of the screws beyond a certain limit.

The connection of larger or stronger bars is therefore not possible.

Secondly, the effort generated by torquing the screws serves to press the racks into the sleeve as much as to press them into the bars.

Finally, its performance under a tensile load is very difficult to maintain and to control.

The precision of this diameter reduction, as well as the radius at the bottom of the reduction, are difficult to achieve.

The stress riser at the reduction may vary from 1 to 4, depending on the radius at the bottom of the reduction, which on top of being difficult to produce accurately, is also difficult to measure and control.

In practice however, it cannot be guaranteed that the pneumatic or electric wrench or screwdriver is perfectly aligned on the axis of the screw.

Because this tool is manually held, a certain angle between its axis and that of the screw is unavoidable.

Such an angle adds a flexural effort to the torsion effect, thereby reducing the torque necessary to shear off the screws, and hence reducing the system performance.

Because friction is not as efficient as gripping in transmitting effort, it compensates by using a longer length and a larger number of screws.

Being so closely related to the other prior art cited, these other prior art systems do not bring any particular additional benefit, while still suffering from the same disadvantage and the additional drawback of bulkiness.

Being so closely related to the other prior art cited, this prior art system does not bring any additional benefits, while still suffering from the same disadvantages and the additional drawback that the angle between the two rows of screws requires extra free space for installation.

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