Resin anchor with a compressible envelope containing a curable product

The resin anchor comprises an apertured tubular envelope designed to be compressed by a traction element, characterized in that it includes, on the inside of the envelope, a resin component and a hardener component that are intended to be mixed together and to cure under the action of the compression of the envelope, in order to fasten the anchor. The traction element is a stud having a threaded rod part that cooperates with a tapped traction element firmly attached to the end of the bushing. The anchor is fastened both mechanically and chemically, for either solid material or hollow material.

RELATED APPLICATIONS

The present application is based on International Application Number PCT/IB2007/000039 filed Jan. 8, 2007, and claims priority from French Application Number 06 00348 filed Jan. 13, 2006, the disclosures of which are hereby incorporated by reference herein in their entirety.

The present invention relates to resin anchors, that is to say anchors that are fastened to a support material by means of resin and a hardener for curing the resin.

Resin anchors exist for solid materials and for hollow materials.

In a solid material, a hole may be drilled and a resin capsule, in which a stick of hardener is embedded, may be slipped thereinto, before the combination is crushed and the two components mixed together. It is also possible to drill a hole and inject resin and a hardener thereinto, the resin and hardener mixing together. A threaded rod or a screw may serve as fastening element.

In a hollow material, after a hole has been drilled in the wall of the material, a tubular screen may be introduced into said hole, resin and a hardener then being injected into said screen, and the resin, expelled out of the screen and after curing, fastening the screen to the rear of the wall. Threaded rod and screw may also be used as fastening elements.

All the abovementioned anchors may be used both in a solid material and in a hollow material.

Also known, for a hollow material, is an element with a bearing flange to which a slit skirt is firmly attached, the skirt being designed i) to be pressed against the rear face of the wall through the action of the tie connecting it to the flange that bears against the front face of the wall and ii) to receive, by injection, a resin/hardener mix for fastening the element to the rear of the wall.

All the abovementioned anchors, which have been known for a long time, are fastened by purely chemical means.

Many of these resin anchors require a resin injection step to be carried out, and the Applicant has sought to dispense with this relatively tedious injection operation. In addition, the Applicant has sought to provide a resin anchor that is not only suitable both for a hollow material and a solid material but that is able to be fastened no longer by purely chemical means but also by mechanical means.

Thus, what it proposes is a resin anchor comprising an apertured tubular envelope designed to be compressed by a traction element, characterized in that it includes, on the inside of the envelope, a resin component and a hardener component that are intended to be mixed together and to cure under the action of the compression of the envelope, in order to fasten the anchor.

It should be emphasized that nothing could have encouraged a person skilled in the art to put, into a resin anchor also having mechanical fastening, thanks to the compression of the compressible envelope, and usable both in a hollow material and a solid material, two components intended to be cured as was done in a hole of a solid material for receiving a fastening element of the threaded rod or tapped bushing type.

Preferably, a tubular sleeve of the two curable components is provided, again preferably placed around the traction element.

Advantageously, the anchor includes an external sleeving for retaining the cure components.

In a first embodiment, the two cure components extend along the sleeve in the form of a sheet of one of the components and in the form of a helix of the other component. There could also be a double sleeve comprising two sheets of the two respective components.

In a second embodiment, the sleeve is a sheet that supports bubbles containing one of the two cure components, the other of the two components coating the traction element, and the sheet being wound around the traction element.

In a third embodiment, the sleeve is a sheet supporting bubbles of the two respective cure components, the sheet being wound around the traction element.

With reference toFIGS. 1-4relating to the first embodiment, the anchor comprises a bushing1, here made of plastic, of axis9, a stud2, enveloped in the bushing1, a curable sleeve3, around the stud2and placed between the stud and the bushing, and a retention sleeving4around the bushing.

The bushing1extends between a bearing flange5and another end6on the opposite side from that of the flange and bearing a traction nut7, as will be explained later.

The tubular envelope of the bushing is apertured by helical slits8extending over most of the axial length of the bushing, between the two ends5,6.

The stud2has, along its axis9, a hollow part10and a solid part11. The hollow part is a small tubular element10provided with a flange12that bears on the flange5of the bushing. This tubular element10has an entrance13shaped, substantially in the plane of its flange12, so that a screwdriver or other screwing bit can engage therein. The hollowed part14of the tubular element of the stud2is designed to receive a screw or other bolt for fastening a component.

The solid part11of the stud is a threaded rod element screwed into the nut7on the end6of the bushing1. It will be understood that, when the stud2is being screwed into the nut7, while the flange12bears against the flange5, the end6of the bushing is drawn towards the flanges, that is to say the apertured tubular envelope of the bushing is compressed. This is why the stud2is called the traction element. The nut7is also a traction nut, just like the end6of the bushing.

It should be noted that it would be possible to dispense with the nut7, or tapped traction element attached to the end6of the bushing, if the end6of the bushing were itself tapped like the screw.

The inside diameter of the envelope of the bushing1, that is to say the diameter of the internal bore17of the bushing1, corresponds very substantially to the outside diameter of the hollowed part14of the stud2. It is very slightly greater than it. The envelope of the bushing extends with such an inside diameter as far as its traction end6.

The outside diameter of the threaded rod part11of the stud2is smaller than that of the hollowed part14so that, between the shoulder15, made between the two parts of the stud10,11of different diameters, and the far end16of the internal bore17of the bushing1, the curable tubular sleeve3may be housed around the threaded rod part11of the stud2. The sleeve3is a sleeve consisting of two curable components, in this case resin and a hardener. In the case illustrated inFIGS. 2-4, the sleeve3is made from a sheet of one of the two components (resin or hardener) which is striped with inclined lines of the other component (hardener or resin) before the sheet is rolled up so as to be closed on itself and then slipped around the threaded rod part11of the stud2in order to obtain the sleeve3of one of the two components coated with a helix18of the other component.

As a variant of this first embodiment, the sleeve of curable components could be obtained from two sheets of the two components, with the same dimensions, placed one on top of the other, before being rolled up together and closed up on themselves.

Having described the resin anchor in terms of its various elements, we will now deal with its use, here in a hollow material20with an outer wall21.

After a hole22has been drilled into the wall21with a diameter very slightly larger than the outside diameter of the envelope of the bushing1, the anchor is introduced into the hole22as far as the point when the flange5of the bushing bears against the external surface23of the wall21. The stud2is then rotated, using a screwdriver or screwing device with a screwing bit24placed in its entrance. The traction end6of the bushing1is pulled back along the threaded rod part11of the stud2, thereby compressing the envelope of the bushing1, causing it to expand, and creating a “lump” at the rear of the wall21, so as already to mechanically fasten the anchor to the wall21.

Concomitantly, the compression of envelope causes the sleeve3to be kneaded and the two components to be mixed together, which mix, during compression of the envelope of the bushing, is partly expelled via the slits8in order to form, at the rear of the wall21, a substance that will cure in order to achieve, by chemical means, perfect fastening of the anchor to the wall21. Thanks to the retention sleeving4, which is here heat-sealed and extensible, the resin does not flow away, it being retained by the sleeving.

The embodiments shown inFIGS. 5-8differ from the embodiment shown inFIGS. 1-4only by the curable sleeve, all the other elements being identical.

In the embodiment shown inFIGS. 5,6, the curable sleeve3′ is made from an inert support sheet30comprising, embedded in it, a matrix of bubbles or capsules31of one of the two components (resin or hardener), the part of the threaded rod11of the stud2being coated (32) with the second component over the portion of its length extending as far as the far end16of the envelope1of the bushing. The sheet is then rolled up so as to be closed on itself, in order to form a curable tubular sleeve3′ which is then slipped around the threaded rod part11of the stud2of the anchor.

When the envelope of the bushing is being compressed, the capsules31are pierced, causing the component in the capsules to be mixed with the component coating the threaded rod part11, before they cure.

The curable sleeve3″ of the embodiment shown inFIGS. 7,8of the resin anchor of the invention is very slightly different from the previous one. It is made from an inert support sheet35embedded in which are two mutually imbricated matrices of capsules or bubbles33of the first component (resin or hardener) and capsules or bubbles34of the other component. The sheet is then rolled up so as to be closed on itself, in order to form a curable tubular sleeve3″ which is then slipped around the threaded rod part11of the stud2of the anchor.

During the compression, all the capsules33,34are punctured before the components mix and cure.

Instead of capsules, microcapsules may be provided.