Anchoring dowel for heavy load e.g. parabolic type antenna support, has shaft comprising middle section surrounded by tubular sections equipped with anchoring splines that form off-set external to shaft under impulsion of fixation screw

Holder (s):

@ Representative (s): CABINET BLEGER RHEIN.

(54) ANCHOR ANCHOR FOR HEAVY LOAD AND FIXING DEVICE INCLUDING SUCH AN ANCHOR.

FR 2 865 249 - A1 (f /) Anchor anchor for heavy loads, intended to be driven into a sealing hole (8) in a partition made of any material, in particular hollow, such as cinder block, hollow brick or the like, this dowel (1) comprising a cylindrical shank (4) with a proximal end (2) for engaging a fixing screw, more particularly a lag screw, and a distal end (3) extended by an anchoring tip ( 9), axially split.

This anchoring pin is characterized by the fact that the shank (4) is defined to be of great length and comprises a middle part (16) split in the longitudinal direction and framed by tubular sections (19, 20) equipped with anchoring tabs (21) provided capable of being maintained and / or pushed back into a protrusion forming a step outside the shaft (4), under the impulse of said fixing screw.

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The invention relates to an anchor for heavy load intended to be driven into a fixing hole in a partition made of any material, in particular hollow, such as cinder block, hollow brick or the like, this anchor comprising a cylindrical shaft with a proximal end engagement of a fixing screw, more particularly a lag screw, and a distal end extended by an axially split anchoring tip. The invention also relates to a fixing device comprising such an ankle and a lag screw.

Numerous anchoring plugs are already known for fixing against a support, such as a partition, a wall or the like, any object. In fact, whatever the type of anchor envisaged, that is to say metal or plastic, one encounters many difficulties when it comes to ensuring through them the anchoring of a heavy load. , especially if the support is formed by a friable hollow body.

The solution adopted until now consists in choosing the type of anchor according to the material composing the support.

Thus, in the presence of a solid material, the use of expandable metal anchors is recommended which, although they offer very good resistance to tearing, are nonetheless a high cost and implementation cost. delicate work, often using specific tools.

If one places oneself in the context of a support made of hollow material, for example concrete blocks, in the form of a honeycomb block, so-called chemical anchors are usually used for taking up heavy loads. After engaging such an anchor in a sealing hole, there is injected an anchoring material of the composite type or the like.

Here again, these chemical anchors have a high cost price and their resistance to tearing is only effective after hardening of the injected material, so that their implementation requires a longer intervention time.

At the same time, plastic anchors have been developed to meet the particular constraints linked to hollow materials, such as concrete blocks or hollow bricks. Very generally, these plastic anchors comprise, at their end for introducing a fixing screw, the so-called proximal end, a support flange intended to come into contact with the surroundings of the sealing hole made in the support. In addition, they are defined capable of producing an expansion under the effect of the tightening of the fixing screw so that the anchoring takes place essentially at a single wall of the hollow material. In addition, such anchors are often devoid of means preventing their rotation in the fixing hole, before expansion.

Thus, for example, to be able to expand during tightening of the fixing screw, this plastic plug comprises, on a part along its shank, axial slots so as to delimit the tongues which, under the effect tightening of the fixing screw in engagement with the thread of a tip defining the distal end of this plug, are able to brace themselves and produce this desired expansion effect.

The shank of the ankle can also be provided capable of achieving this expansion by torsion, when the fixing screw is tightened.

If it is understood that such anchors, engaged, almost exclusively, on the external wall of a hollow material of the cinder block or brick type, are incapable of providing sufficient anchoring to support heavy loads.

In particular, to produce an anchoring, not at the level of such an external wall, but at the level of intermediate walls delimiting the cells that these concrete blocks or these bricks comprise internally, it has been imagined to lengthen these plastic anchors, while their the distal end, opposite the proximal end of introduction of the fixation screw, has been designed to be able to widen when the fixation screw passes.

Quite particularly, such an anchor is described in document FR-2,800,812.

Thus, the shank of this ankle has at its proximal end for introducing the fixing screw a bearing flange, while the distal end is defined by an anchoring end split axially so as to define two semi-lips. -cylindrical. The slot of the anchoring end piece extends in part into the barrel, which also comprises, on the outside, longitudinal ribs, diametrically opposed, to fulfill a function of reinforcement and stiffening and ensure a function of holding and anchoring in the sealing hole. If, in this case, these longitudinal ribs extend more particularly at the level of the split part of the barrel, it is also known practice to implant such ribs immediately behind the support flange to guarantee an anti-blocking function. -rotation.

The anchor end piece has grooves on the outside so as to define hooking beads forming a step. In addition, this end piece is also provided with projecting hooking tabs, which can be elastically folded along the barrel when the pin is introduced into the sealing hole. More precisely, these tabs, when passing through a hole in a cinder block or brick wall, are liable to be erased by being folded back along the shank of the ankle, knowing that once the wall has been crossed, they resume their protruding position to oppose a displacement in the opposite direction of this peg.

Thus, just like the anchoring end piece at the distal end, these hooking tabs contribute to the anchoring of the ankle in its fixing hole.

Be that as it may, it will be noted that these fastening tabs in themselves only offer relatively reduced mechanical strength. In fact, they can only have a very small thickness so as not to constitute a local increase in the section of the ankle capable of preventing the introduction of the latter into the sealing hole.

In short, only the anchoring end piece at the distal end of this ankle is capable, really, of opposing a pullout force corresponding to the support of a heavy load.

The object of the present invention is to design an ankle which is equipped, substantially over its entire length; means capable, actually, of providing a strong anchoring, in particular in a hollow material, such as concrete block, hollow brick or the like.

To this end, the invention relates to an anchoring plug for heavy load intended to be driven into a fixing hole in a partition made of any material, in particular hollow, such as cinder block, hollow brick or the like, this plug comprising a barrel. cylindrical with a proximal end for engaging a set screw, plus

<td>particularly</td><td>a lag screw, and a distal end</td>

<td>extended by</td><td>an axially split anchor end,</td>

<td>characterized by</td><td>the fact that the barrel is defined large</td>

<td colspan="2">length and forms a middle part framed by sections</td>

<td>tubular equipped</td><td>anchoring tabs provided suitable for</td>

<td>maintained and / or</td><td>pushed back to form a step,</td>

<td>externally to the binding.</td><td>barrel, driven by said screw</td>

<td>So</td><td>advantageous, the anchoring tabs are</td>

designed through a "U" cutout made in the wall of the barrel and are defined with a thickness greater than this wall of the barrel.

In particular, at the level of each tubular section, at least two diametrically opposed anchoring tabs are provided.

According to another particularity of the invention, the two lips of semi-cylindrical section, defining the anchoring end piece, are secured by a connecting tab at least in their free end part, preventing their separation when engaging. the dowel in the fixing hole.

The invention also relates to a fixing device comprising such an ankle and a lag screw, the rod of which, extending under the head, is threaded over its entire height, which is at least equal to the length of said ankle.

The advantages which result from the present invention consist in that, in combination with the anchoring end piece, the anchoring tabs defined in the thickness of the wall of the barrel, are able to provide a real anchoring of the ankle. in a sealing hole. Thus, in collaboration with the outer and inner walls of a hollow material, they are able to oppose the extraction of the plug from its sealing hole under the effect of the stresses applied by the heavy load supported.

Such dowels, in accordance with the invention, could contribute, for example, to the fixing of antenna supports, in particular of the parabolic type, on the walls of hollow material of a building. Although such parabolic antennas do not always constitute heavy loads in themselves, their wind resistance is such that they can impart to the fasteners a breakout force and significant vibrations.

The ankle, object of the invention, is able to oppose such a tearing force through:

- from the anchor tip to the distal end;

- hooking lugs that includes the middle part of its shaft;

- anchoring tabs at the front and rear of this middle parie.

In short, just like a chemical anchor which provides anchoring over its entire length in the hollow material in which it is engaged, the anchor, object of the invention also provides such an anchoring substantially over its entire length introduced into the fixing hole. In addition, whatever the thickness of the coating applied to a support wall and the position taken by the anchor in the fixing hole, it always offers the same efficiency.

Other objects and advantages of the present invention will become apparent during the description which follows relating to an exemplary embodiment given by way of indication and without limitation.

Understanding of this description will be facilitated by referring to the attached drawing in which:

- Figure 1 is a schematic representation of the anchoring pin, object of the present invention;

- Figure 2 is a schematic representation in section along II-II of Figure 1;

- Figure 3 is a schematic representation of the implantation of this plug in a hollow concrete block type.

As can be seen in the figures of the attached drawing, the present invention relates to an anchoring plug 1, provided suitable for receiving a fixing screw, of the lag type.

If this pin 1 is capable of being engaged in a fixing hole made in any support, in particular in a partition made of solid material, it will be very useful in application with hollow materials, in particular friable, such as concrete blocks or hollow bricks.

Thus, it has a proximal end 2 through which the lag screw is provided capable of being engaged and a distal end 3.

More particularly, this ankle 1 reinforces a shank 4 equipped, on the side of the proximal end 2, with a support flange 5 intended to come into contact with the external wall 6 of the support 7, as visible in FIG. 3. Thus, this support flange 5 limits the insertion of the pin 1 into the fixing hole 8. This flange is particularly designed so as not to create any extra thickness around this fixing hole.

At its distal end 3, the shank 4 is extended by an anchoring tip 9, split axially, so as to define two lips 10, 11 of semi-cylindrical section and, which, under

The impulse of a fixing screw come apart and provide an anchoring in the material making up the support 7. Preferably, these two lips 10, 11 are secured by a connecting tab L, at least in their part d free end, avoiding their separation when engaging the plug in the fixing hole 8.

As for the shank 4 of the plug 1, it is defined to be of great length so that this anchoring end piece 9 is able to cooperate with at least one intermediate wall 12 delimiting the cells 13 inside the support 7 made of hollow material.

It should also be noted that the anchoring end piece 9 comprises a plurality of peripheral grooves 14 so as to define annular beads 15 capable of forming a step with regard to an attempt to extract the pin 1 from the hole. sealing 8.

Coming back to the shank 4 of this peg 1, according to the invention, it comprises a middle part 16 along which are meant axial ribs 17 which improve its mechanical strength, in particular against the twisting of this peg 1. Advantageously, the latter may be provided with two series of diametrically opposed ribs 17 along the shaft 4,

According to yet another feature of the invention, this middle part 16 of the shank 4 is framed by tubular sections 19, 20 equipped with anchoring tabs 21 provided capable of being maintained and / or pushed back in projection, forming a step outside the shank 4 , under the impulse of said fixing screw.

In particular, such an anchoring tongue 21 is delimited through a "U" shaped cutout 22 made in the wall 23 of the barrel 4 in such a way, on the one hand, that this tongue 21 extends in the direction longitudinal with respect to the ankle 1 and, other than its free end 24 is oriented towards the distal end 3 to form a step during an attempt to extract the ankle 1 from its sealing hole 8.

In addition, at the height of its free end 24, this tongue 21 is defined with a thickness 25 greater than the thickness of the wall 24 of the barrel 4. Thus, when the plug 1 is introduced into its sealing hole 8, such a tongue 21 necessarily extends in the bore 26 of this barrel 4. As this bore 26 is adjusted substantially to the cross section of the fixing screw, when the latter is introduced, the tongues 21 are pushed back radially so as to necessarily project outwardly from the barrel 4 and thus ensure their anchoring function. .

Note that such tongues 21, preferably at least two in number diametrically opposed at the level of the tubular sections 19, 20, can be provided naturally projecting on the periphery of the barrel 4, so as to be pushed elastically in the direction of the axis. of the pin 1 when the latter is engaged in the sealing hole and, thus, allow them to regain their protruding position, as soon as an external or intermediate wall exceeds the level of the support made of hollow material, without this position necessarily being reached only through the engagement of the fixing screw. However, a reverse arrangement can be considered.

It should be noted that on the outside and in particular at the height of their free end 24, such tongues 21 may have asperities, for example a grooving or the like, intended to promote their attachment to the level of the walls of the sealing hole 8. In this way. , these tabs 21 also prevent twisting of the ankle 1.

Ultimately, the presence of these tabs 21 at the level of the tubular sections 19, 20 flanking the median part 16 of the barrel 4 allows an expansion of these tubular sections 19, 20 under the action of the tightening of the lag screw. This results in an advance of the ankle 1 relative to the support 7 in which it is introduced. This peg 1 therefore comes to rest perfectly on the outer wall 6 of this support 7 through its support flange 5.

In addition, it is provided, along the shank 4, in a diametrically opposed manner and, in particular, staggered with respect to the axial ribs 17 of the hooking tabs 28. These extend, preferably, in a plane perpendicular to the anchoring tabs 21 and naturally protrude at the periphery of the barrel 4. They are still capable of being pushed back elastically into a retracted position along the wall of this barrel 4. In fact, these hooking tabs 28 are, again, oriented so as to oppose the extraction of the pin 1 from its sealing hole. Thus, they are arranged axially so that their free end 29 is oriented towards the distal end 3 of the ankle 1.

Under the support flange 5 which the latter comprises at its proximal end 2 and outside the shaft 4, axial anti-rotation ribs 30 may be formed, more particularly intended to ensure the immobilization in rotation of the ankle 1 during the engagement of the fixing screw and before the various anchoring means are effective. Such ribs also provide an anti-twisting function of the ankle under the action of the tightening of the lag screw.

According to another feature of the invention, axially along the wall of the bore 26, substantially adjusted to the section of the lag bolt, ribs 31 are formed defining an inscribed section 32 lower than that of the lag bolt to improve the held to the tearing of the latter.

In this connection, the invention also relates to a fixing device comprising an ankle 1, as defined above, and a screw 33 whose rod 34, extending under the head 35, is threaded over its entire height, which is at least equal to the length of said ankle 1.

As emerges from the above description, the ankle, object of the invention, provides a real solution to the fixing of heavy loads on supports, such as walls, partitions or the like, made, more particularly, of hollow materials, for example concrete blocks, bricks or the like.

Although the invention has been described with reference to a particular embodiment, it is understood that it is by no means limited thereto and that various modifications of shapes, materials and combinations thereof can be made thereto. 5 various elements without thereby departing from the scope and spirit of the invention.