WO1992008019A1

WO1992008019A1 - Device for end-to-end joining two rods

Info

Publication number: WO1992008019A1
Application number: PCT/FR1991/000852
Authority: WO
Inventors: Marcel Arteon
Original assignee: Marcel Arteon
Priority date: 1990-10-29
Filing date: 1991-10-29
Publication date: 1992-05-14
Also published as: FR2668800B2; FR2668800A2; EP0517865A1

Abstract

Device for end-to-end joining of two threaded rods. According to the invention, the two rods are joined by a socket (1) inside of which are screwed two nuts (3, 13), the nuts resting against sleeves (4, 14), screwed on the ends of the rods (2, 12), the diameter of said sleeves being less than the internal diameter of said socket (1) while the internal diameter of the nuts is considerably greater than the diameter of the rods (2, 12).

Description

CONNECTION DEVICE FOR JOINING END TO END TWO BARS.

The present invention relates to a connecting device for joining end to end two bars whose at least the ends are threaded, intended in particular but not exclusively, for the building industry.

In general, it is easy to join end to end two free threaded bars using a socket having two threads in opposite directions or not, at each of its ends. The connection is then made by a simple rotation of the sleeve or by screwing the first bar

10 in the first half of the bushing then screwing the second bar into the second half of the bushing.

But in the building industry, you often have to join two threaded bars that are immobilized at least in

15 rotation. Thus, it frequently happens that the ends of the two bars do not come into contact with each other. In addition, it can also be seen that, as a rule, the bars are not exactly aligned. Under these conditions, a threaded sleeve cannot bond the bars.

20

In order to remedy the misalignment of two reinforcing bars or bars, it has already been proposed to bring the ends of the bars into a sleeve, then to fix them „_- by means of small radial screws so to apply them on seats forming a "V" which produces an automatic centering and consequently their alignment. A resin then makes it possible to block the reinforcements inside the sleeve. However, the use of centering screws leads to injury to the steel, which is undesirable. Furthermore, the introduction of resin delays the site for the time necessary for the polymerization thereof. Mechanical connections are known from US-A-3,278,210 in which a threaded sleeve at its two ends receives two sockets each secured to a bar.

US-A-4,081,219 describes a coupling of the ends of two cables or benches allowing a pre-tension to be established thereon. In a hollow socket are mounted two threaded rings in one of which is screwed the end of a cable while the end of the second cable is screwed in a stop piece bearing on the second ring. But these connections do not make it possible to make up for the misalignments mentioned above.

The object of the present invention is to overcome these drawbacks and to allow the end-to-end connection of immobilized bars when these are not exactly aligned and / or do not come into contact with each other or when the bars axes have a relative inclination.

According to the present invention, the end-to-end connection device for two bars comprising a hollow socket intended to receive the ends of the two bars, at least one end of the socket being threaded, a hollow nut allowing the axial passage of a bar being screwed onto said end, characterized in that it comprises at least one stop piece fixed to the end of a bar coming into contact with the internal face of the nut, the external transverse dimensions of the stop piece being smaller to the internal transverse dimensions of the sleeve.

By internal transverse, lower dimensions of the abutment piece, it will be understood that the abutment part has a clearance inside the bushing which allows make up for misalignments for example of the order of 1 to 2 centimeters.

The connection device according to the invention can be symmetrical, the sleeve being tapped or threaded at its two ends. It can also be disy etric and in this case, the structure of the socket is generally more complex. The socket is of generally hollow cylindrical shape and the external diameter of the abutment piece is less than the internal diameter of the socket. Thus, by radial displacement of the abutment piece inside the sleeve it is possible, to a certain extent, to make up for the alignment differences between the two bars.

Other characteristics and advantages of the invention will appear during the description which follows of particular embodiments, given solely by way of nonlimiting examples, with reference to the drawings which represent:

- Figure 1, a sectional view of the mounting of a device according to the invention when the two ends of each of the bars are in contact with each other, the two bars being aligned;

- Figure 2, in the same positions the same connecting device in the case where the two parallel bars are not aligned;

- Figure 3, an alternative embodiment in which the nut is screwed onto the external surface of the sleeve;

- Figure 4, an asymmetrical connection device; - Figure 5, an assembly of the connecting device in the case where the ends of the two bars to be joined are not in contact with each other;

- Figure 6, an assembly of two non-aligned bars. In the examples which will be given below, the bars are quick step bars used in the building industry and known, for example, under the names of "DYWIDAG" or "GEWI" (Trademarks). On the other hand, certain elements are threaded at a pitch conforming to the ISO standard for example. But of course, the invention is independent of the mode of threading or tapping. Still in the examples, the abutment pieces consist of sleeves which are screwed on. the ends of the bars. However, these stop pieces can also be crimped or welded rings in the workshop before assembly on site.

In Figure 1, there is a cylindrical sleeve 1. Inside this sleeve, are included the ends of two bars, respectively 2 and 12, which are aligned and in contact with each other. On the end of the bar 2 is screwed, by a thread 6, a sleeve 4 or stop piece, the external surface of which is cylindrical and smooth. As shown in the figure, the sleeve 4 is slightly set back from the contact plane between the bars 2 and 12 so as to release a space 9. The second end of the sleeve 4 is in contact with the internal face of a nut 3 The nut 3 is screwed into the socket 1 by an ISO thread 5. Likewise, on the other side of the socket, the nut 13 comes to bear against a sleeve 14 which is screwed by a rapid pitch tapping on the bar 12.

According to a characteristic of the invention, the diameter of the sleeves 4 and 14 is less than the internal diameter of the sleeve 1 and releases a space 7 allowing an alignment take-up. The nut 13 is screwed onto the sleeve 1 by a thread 6. Of course, the threads 5 and 6 are threaded in opposite directions, that is to say that if the thread 6 is on the left, the thread 5 is on the right for ensure mutual blocking. If the step difference between the two nets 5 and 6 is important, we can, if need be, carry them out in the same direction.

Note that the internal non-threaded diameter of the nuts 3 or 13 is greater than the diameter of the bars 2 and 12 so as to allow a connection of these bars with respect to one another when the latter are not aligned. The assembly is symmetrical and the socket D is tapped according to the ISO standard at its two ends. The sleeves 4 and 14 are externally cylindrical and enter the sleeve 1 with a very large clearance. It is thus possible to make up for a misalignment of the order of one centimeter, for example. The nuts 3 and 13 are threaded on the outside and are screwed inside the socket. They can be tightened by a hexagon and the clearance of the rod or bar 2 or 12 is equal to that which was created between the sleeve 1 and the sleeves 4 and 14. The assembly of the assembly is ensured by the sleeve 1 .

Figure 2 which is similar to Figure 1 shows the mounting of two non-aligned bars. The sleeve 14 can come into contact with the internal surface of the sleeve 1. However, the connection nevertheless remains as strong as ever.

In this embodiment, as in the previous one, the sleeves 4 and 14 are not in contact with each other and prestressing can be applied by means of a wrench to the two nuts 3 and 13. The ends of the bars are always in contact with each other, on a sufficient surface.

In Figure 3 there is shown another embodiment which differs from the first only by the shape of the nut 23. The sleeve 1 is externally threaded at its two ends and the nut 23 is tapped so as to be able to screw on the outside of socket 1. The other part of the connection (not shown) is perfectly symmetrical. This type of nut makes it possible to have a connection device slightly shorter than in the previous example but whose radial size is greater. The choice of nut type therefore depends on the work to be carried out.

In these two cases, the mounting method is as follows: firstly, the nut 3 or 23 is placed on the rod 2. Given the significant play existing, the nut moves freely on the rod and possibly can fall until it is held, for example, by a concrete block with reinforcements waiting to be connected to upper reinforcements. The sleeve 4 is then screwed onto the bar 2, leaving a clearance 9 so that the bars actually come into contact with one another. Then the sleeve 1 is slid around the bar 2 until it comes onto the nut 3 or 23.

The nut 13 is then slid onto the bar 12 and then the sleeve 14 is screwed to the front end of the bar 12, the thread being a quick pitch thread. The socket is positioned and the two nuts 3 and 13 are then brought together and are screwed inside the socket. The screwing is stopped by the abutment of the nuts against the external faces of sleeves 4 and 14 respectively. A prestress is then applied using a torque wrench, the contact of the sleeves 4 and 14 on the nuts 3 and 13 avoiding any separation of the bars 2 and 12. The forces are transferred to the bush 1.

FIG. 4 represents an alternative embodiment in which the device is no longer symmetrical. That is to say that the sleeve 11 has an internal thread by which it is screwed at the end of the rod 12. As before, the nut 3 is slid over the bar 2 and the sleeve 4 is screwed (with rapid pitch) onto the end of rod 2. These operations are, of course, carried out before the ends of the bars are brought together. In this case, the sleeve 11 has on one of its ends a hexagon. In the example shown, the two bars 2 and 12 are in end-to-end contact. The sleeve 4 is not in contact with the groove formed inside the sleeve 11 and a space 9 remains in front of the sleeve 4. In fact in this embodiment the nut 13 has been somehow integrated into the socket. But, of course, we can only make up for half of the misalignment that we could correct in Figure 1.

FIG. 5 represents a connection device in the case where the ends of the bars cannot come into contact with one another. As indicated previously, it is not possible in the building to obtain a very precise positioning of the reinforcements of a concrete structure and in this case, it is necessary that the connection device can somehow make up for the difference in height in the case of a vertical connection or the difference in length of the two bars. As before, we find the socket 1, the ends of which have two ISO 5 threads. As before, nuts 3 and 13 are screwed into these threads, but the ends of the two bars 2 and 12 are not in contact. Sleeves 4 and 14 are screwed, with rapid pitch, on the ends of the bars 2 and 12. In this assembly, it is essential to provide a blocking for example by means of the locknuts 15 intended to ensure a prestressing between the bars 2 and 12 and the sleeves 4 and 14 which are face to face and bear one against the other by tightening the nuts 3 and 13. Of course, and as before, this range can be variable depending on the lateral deviation to be compensated. The mounting method is the same as above except that the sleeves 4 and 14 project from the ends of the rods. In this case, however, length of the threads 5 must be provided for being used only in part and it is necessary to determine beforehand a maximum distance between the bars so that a sufficient number of threads are engaged. The sleeves 4 and 14 touch each other and their length defines the depression of the nuts 3 and 13 inside the sleeve 1. In this case, there remains a space 10 between the bars 2 and 12. The sleeves are blocked by the nuts 3 which are themselves locked by the locknuts 15. In this assembly,. the prestressing is exerted on the sleeves and not on the bars.

In the examples which have just been given, the abutment parts consist of sleeves 4, 14. However, the present invention can be implemented with bars of non-threaded concrete steel. In this case, the abutment pieces constituted by rings or the like are joined together in the workshop with the end of the bars by crimping, welding or even forging, after insertion of a nut 3 or 13. But, in accordance with the invention, the radial dimensions of the rings or other added elements must be less than the internal diameter of the sleeve in order to allow clearance.

The sleeving according to the invention can be filled with grease, a cement or resin grout, either during assembly, or by injection through a hole drilled in the socket.

The invention also allows the connection of bars of different diameters.

However, there may be cases where the axes of the bars to be joined form an angle of a few degrees between them. According to another characteristic of the invention, the connecting device is characterized in that the rear face of at least one of the sleeves is curved so as to be able to bear on the nut in an angular position varying by a few degrees around the axis of the nut.

Figure 6 shows in vertical section such an arrangement. In this figure, the sleeves 4, 14 are frustoconical and have a curved rear face 16 resting in a bowl 17 formed inside the nuts 3, 13.

Thus, the bearing surface of the sleeves on the front face of the nut is no longer flat but is more or less spherical.

The body of the sleeves. 4, 14 is of generally frustoconical shape to allow maximum angular displacement inside the bush 1 and with respect to the axis of the latter.

Preferably, the front part of the nut receiving the convex face 16 of the sleeve is shaped into a bowl 17 to ensure a better, substantially ball-and-socket type bearing of the sleeve against the nut.

The two sleeves of the same device can have the same structure or be different.

Thus, if in the case where a set of rebar has to be joined on bars extending substantially in the same direction, it is possible by replacing a cylindrical sleeve with a domed frustoconical sleeve to compensate for a limited angular deviation. It is also possible, in the case of a cylindrical sleeve, to provide an internal cavity eccentric relative to the axis of the sleeve.

This arrangement makes it possible in certain cases to compensate for larger deviations in alignment.

The sleeve can in certain cases be crimped at the end of a threaded bar or not. It is also possible to forge at the end of one or both bars a protuberance intended to ensure the function of the sleeve, that is to say essentially the contact with the nut.

It is of course possible to join or link two bars, one of which is threaded and the other of which is not, or bars of which only the end is threaded.

It goes without saying that many variants can be introduced, in particular by substitution of technically equivalent means without departing from the scope of the invention.

Claims

1) Device for end-to-end connection of two threaded bars, comprising a hollow socket intended to receive the ends of the two bars, at least one end of the socket being threaded, a hollow nut allowing the passage of a bar being screwed onto said end, characterized in that it comprises at least one stop piece (4, 14) fixed to the end of a bar coming into contact with the internal face of the nut (3, 13), the transverse dimensions external of the abutment piece (4, 14) being smaller than the internal transverse dimensions of the sleeve.

2) Device according to claim 1, characterized in that the abutment parts (4, 14) are constituted by cylindrical sleeves internally threaded and screwed onto the ends of the bars (2, 12).

3) Connecting device according to one of claims 1 or 3, characterized in that the threads of the sleeve (1) and the threads of the bars (2, 12) are at different steps and in opposite directions.

4) Connecting device according to one of claims 1 to 3, characterized in that locknuts (15) are mounted on the rods (2, 12) outside the nuts (3, 3 ').

5) Connecting device according to one of the preceding claims, characterized in that the nuts (3, 13) are internally threaded to a diameter corresponding to the external thread of the sleeve (1). 6) Connecting device according to claim 1, characterized in that the sleeve (11) has a first internal thread (6) at one of its ends and a second thread (5) of diameter greater than its other end.

7) Connecting device according to claim 1, characterized in that the abutment parts (4, 14) are constituted by rings secured to the ends of the bars (2, 12).

8) Connecting device according to claim 1, characterized in that at least one abutment part (4, 14) has on the outside a curved face (16).

9) Connecting device according to claim 8, characterized in that the body of the abutment piece (4, 14) is substantially frustoconical.

10) Connecting device according to one of claims 8 or 9, characterized in that the inner part of 1 "nut (3, 13) forms a support bowl (17) intended to receive the curved surface (16) of the stop piece (4, 14).

11) Connecting device according to claim 1, characterized in that the internal thread (6) of the stop piece (4, 14) is eccentric with respect to its axis.

12) Device according to any one of the preceding claims, characterized in that a protuberance is forged at the end of at least one bar (2, 12) to constitute a stop piece (4, 14).