Patent Description:
Closing plugs for covering and concealing holes in concrete walls and the like are known. Said holes are usually made by the manufacturing process of said concrete walls.

Concrete walls are manufactured on site, providing a gap between two formwork panels that are arranged in such a way that they face each other. These panels are secured together by means of an anchoring system comprising transverse bolts the ends of which are threaded. Said threaded ends protrude from the formwork panels so that the corresponding nuts can be threaded, thus securing the formwork panels.

Once the panels are secured, concrete is poured into the gap which is sandwiched between the formwork panels. For the concrete not to adhere to the transverse bolts once it has set, said bolts are previously lined by placing them in a tube, preferably made of plastic, and cones or frustoconical elements, also made of plastic, are placed at the ends to facilitate supporting against the formwork. Once the concrete has set, the formwork panels, transverse bolts, and cones or frustoconical elements are disassembled. The removal of the protective tube is optional, but since this operation is fairly tedious, many times said tubes are not disassembled and remain inside the wall.

Upon disassembling the anchoring system of the formwork panels, i.e., upon disassembling the transverse bolts and cones or frustoconical elements, through holes are generated in the concrete wall. To conceal said holes, closing plugs, preferably having a frustoconical shape, are placed in said holes, which plugs are secured in the wall by means of applying an adhesive. Other means for securing said plugs are also known.

In this sense, <CIT> describes a decorative plug for concealing a hole in a concrete wall, which hole is generated by the manufacturing process of said wall. Said plug comprises a main body made of plastic and elastic retention means, also made of plastic, which retain the plug in place inside the protective plastic tube of the hole in the concrete wall. The plug comprises a frustoconical head and a cylindrical appendage extending from said head. A decorative metallic disc is fixed at the end of the head by means of adhesive. The elastic means comprise in one embodiment a plurality of elongated ribs arranged on the appendage such that they radially protrude.

<CIT> describes a plug for closing a hole in a concrete wall, comprising a main body and conically tapering retention means. The retention means comprise a sleeve shaped body, which is partially embedded in the main body, and three encircling hooks projecting from the sleeve shaped body, the plug being retained inside the hole by the hooks.

<CIT> discloses a plug for closing a hole in a concrete wall.

The object of the invention is to provide a plug according to claim <NUM>.

The plug of the invention comprises a main body and elastic retention means, said retention means being partially embedded in the main body. The retention means also comprise at least one set of two hooks arranged diametrically opposite to one another and at least partially projecting from the main body, said hooks being configured for cooperating with the hole of the concrete wall for retaining the plug in said hole.

Each hook comprises a respective retention flange, the free end of the flange being at a distance from a longitudinal axis of the plug, said distance being greater than the radius of the hole of the concrete wall to be plugged, such that, in use, with the plug being arranged inside the hole to be plugged, the flange is compressed inside the hole.

The two retention flanges are attached to one another by a U-shaped retention element, part of said retention element being embedded in the main body.

Placing said plug in the hole in the concrete wall is facilitated with the plug of the invention because it is not necessary to use additional means, such as adhesives, for example, to retain the plug in place. Furthermore, the securing of said plug is also improved because the hook of the elastic means provides good securing whether the hole to be plugged comprises the protective plastic tube of the transverse bolts (securing on a plastic material) or does not comprise said tube (securing directly on the concrete).

These and other advantages and features of the invention will become apparent in view of the figures and detailed description of the invention.

<FIG> show a first embodiment of the plug <NUM> according to the invention. As shown in said figures, the plug <NUM> of the invention comprises a main body <NUM> and elastic retention means <NUM>, the retention means <NUM> being partially embedded in the main body <NUM>. According to the invention, the retention means <NUM> comprise at least one hook at least partially projecting from the main body <NUM> and configured for cooperating with the hole <NUM> in the concrete wall <NUM> for retaining the plug <NUM> in place inside said hole <NUM>. The retention means <NUM> can also comprise a plurality of hooks protruding at least partially from the main body <NUM>. In the non-limiting example of <FIG>, for example, the retention means <NUM> comprise four hooks arranged as will be described in detail below.

The plug <NUM> in use, i.e., when the plug <NUM> is introduced in the hole <NUM> to be plugged, is aligned with the wall or concrete wall <NUM>, thereby concealing said hole <NUM>, as can be seen in <FIG> for example. Holes in concrete walls are unavoidable because most, if not all of said holes, are caused by the manufacturing process of the concrete wall <NUM> itself.

The plug <NUM> of the invention provides an easy placement of the plug <NUM> in the hole <NUM> in the concrete wall <NUM> to be plugged because it is not necessary to use additional means, such as adhesives, for example, for retaining the plug <NUM> in place. Furthermore, the securing of said plug <NUM> is also improved because the hook or hooks of the elastic means <NUM> provide very good securing whether the hole <NUM> to be plugged comprises the protective plastic tube of the transverse bolts (securing on plastic material) or does not comprise said tube no (securing directly on concrete).

In the preferred embodiment of the invention shown in <FIG>, the retention means <NUM> comprise a plurality of hooks, preferably four, each hook comprising a retention flange 4a forming an acute angle α with respect to a longitudinal axis X of the plug <NUM>, as can be seen in <FIG>, or in greater detail in <FIG>, each retention flange 4a extending in a direction opposite an insertion direction A one of the plug <NUM>, wherein the plug <NUM> is brought closer to the hole <NUM> to be plugged. As a result of the configuration of these flanges 4a, the plug <NUM> of the invention is easily arranged in place because no great effort is required to insert the plug <NUM> inside the hole <NUM> to be plugged, but at the same time the flanges 4a provide good securing which lasts over time such that additional means, such as adhesive, for example, are not necessary to keep the plug of the invention in place.

The free ends of the flanges 4a of the retention means <NUM> are arranged at a distance d from the longitudinal axis X of the plug <NUM>, said distance d being greater than the radius of the hole <NUM> in the concrete wall <NUM> to be plugged, such that, in use, with the plug <NUM> being arranged inside the hole <NUM> to be plugged, and preferably aligned with the concrete wall <NUM>, the flanges 4a are compressed inside the hole <NUM>, as can be seen in <FIG>, the free ends of the flanges 4a in this case being at a compressed distance d' from the longitudinal axis X of the plug <NUM>, said compressed distance d' being less than the initial distance d. That is, the retention flanges 4a are compressed upon entering the hole <NUM> to be plugged, with the securing force of the plug <NUM>, which force is exerted by the flanges 4a against the surface of the hole <NUM> to be plugged, being thereby increased. The hooks of the retention means <NUM>, independently of the inner surface of the hole <NUM> to be plugged, exert very good gripping pressure; therefore, independently of whether the hole <NUM> to be plugged comprises the protective plastic tube of the transverse bolts, necessary in the manufacturing process of the concrete wall <NUM>, or does not comprise said tube, the flanges 4a of the hooks of the retention means <NUM> adapt to the surface of the hole <NUM> to be plugged, the plug <NUM> of the invention being strongly secured inside the hole <NUM> to be plugged, regardless of the texture of the surface of said hole <NUM>, of plastic (in the event that the hole comprise the plastic protective tube of the transverse bolt), or of concrete (in the event that it does not comprise said plastic protective tube). In the example of <FIG>, the hole <NUM> to be plugged does not comprise the protective plastic tube; therefore, the hooks of the retention means <NUM>, i.e., the flanges 4a, apply pressure directly on the concrete.

If the retention means <NUM> of the plug <NUM> of the invention comprise a plurality of hooks, these hooks are arranged equidistantly around the longitudinal axis X of the plug <NUM>. To facilitate the manufacture of the plug <NUM> of the invention, the retention means <NUM> comprise at least one set of two retention flanges 4a arranged diametrically opposite to one another, the two retention flanges 4a being attached to one another by a U-shaped retention element <NUM>, as can be seen in <FIG>. That is, at each end of the U-shaped retention element <NUM> there is arranged a corresponding retention flange 4a, correct securing of the plug <NUM> inside the hole <NUM> to be plugged thus being assured. Part of the retention element <NUM> is embedded in the main body <NUM>, preferably the central part, whereas at least part of the retention flanges 4a emerge from the main body <NUM>. However, in the preferred embodiment of the invention, the retention means <NUM> comprise two sets of two retention flanges 4a, both sets being arranged rotated with respect to each other, preferably <NUM>°.

In the preferred embodiment of the invention, the retention element <NUM> of each set comprises a base 5a and two legs 5b, each one attached to a corresponding end of said base 5a, as can be seen in <FIG>, forming a single part. In the example of <FIG>, the legs 5b and the base 5a are attached perpendicularly, said legs 5b being arranged in this case parallel with the longitudinal axis X of the plug <NUM>. However, the legs 5b can form another different angle with the base 5a, in which case the flanges 4a would continue to form the acute angle α with respect to the longitudinal axis X of the plug <NUM>.

The retention flanges 4a can form an acute angle α with respect to the longitudinal axis X of the plug, or they can be perpendicular to said longitudinal axis X, as will be described in detail below.

In the preferred embodiment of the invention, the main body <NUM> comprises a frustoconical or cylindrical head <NUM>, the main body <NUM> comprising an active surface 6a, arranged at one end of the head <NUM>, which in use is aligned with the uncovered face 9a of the wall or concrete wall <NUM>, thus concealing the corresponding hole <NUM>. In the context of the invention, the uncovered face 9a refers to the visible surface of the concrete wall <NUM>. Said active surface 6a is preferably perpendicular to the longitudinal axis X of the plug <NUM>. The main body <NUM> also comprises an auxiliary surface 6b which in use is arranged inside the hole <NUM> in the concrete wall <NUM>, the retention means <NUM> protruding from said auxiliary surface 6b.

In one embodiment of the invention, the auxiliary surface 6b is facing the active surface 6a, the retention means <NUM> protruding axially from the main body <NUM>, i.e., from said auxiliary surface 6b, in the insertion direction A, as shown in <FIG>. In another embodiment of the invention, the auxiliary surface 6b is the generatrix of the frustoconical or conical head <NUM>, the retention means <NUM> protruding radially from the main body <NUM>, i.e., perpendicular to the longitudinal axis X, as will be described in detail below. The shape of the head <NUM> in the example of <FIG> is cylindrical, whereas in the examples of <FIG> it is frustoconical.

In another embodiment of the invention, the main body <NUM>' also comprises, in addition to the frustoconical or cylindrical head <NUM>, a cylindrical appendage <NUM> having a smaller diameter than the smallest diameter of the head <NUM>, said appendage <NUM> extending from the head <NUM> in the insertion direction A, as can be seen in <FIG>, for example. In this embodiment, the active surface 6a of the main body <NUM>', which in use is aligned with the uncovered face 9a of the concrete wall <NUM>, is also arranged at one end of the head <NUM>, but the auxiliary surface 7b or 7b' of the main body <NUM>' is arranged in the appendage <NUM>. The active surface 6a is also preferably perpendicular to the longitudinal axis X of the plug <NUM>', and the retention means <NUM>, particularly the retention flanges 4a, also protrude from the auxiliary surface 7b or 7b', said auxiliary surface 7b or 7b' also being arranged in use inside the hole <NUM> in the concrete wall <NUM>.

In a variant of the embodiment shown in <FIG>, the auxiliary surface 7b of the main body <NUM>' of the plug <NUM> is one of the bases of the cylindrical body forming the appendage <NUM>, i.e., the base arranged at the free end of said appendage <NUM>, such that said auxiliary surface 7b is facing the active surface 6a of the head <NUM>, the retention means <NUM>, particularly the flanges 4a, protruding axially from the appendage <NUM> in the insertion direction A, as can be seen in <FIG>.

In another variant of this embodiment shown in <FIG>, the auxiliary surface 7b' of the main body <NUM>' of the plug <NUM> is the lateral surface or generatrix of the cylindrical body forming the appendage <NUM>, the retention means <NUM> protruding radially from the appendage <NUM>, i.e., perpendicular to the longitudinal axis X, as shown in <FIG>.

In these embodiments, i.e., in embodiments in which the main body <NUM>' comprises both the head <NUM> and the appendage <NUM>, the retention flanges 4a can form an acute angle α with respect to the longitudinal axis X of the plug of the invention, and the retention means <NUM> can also comprise at least one set of two retention flanges 4a arranged diametrically opposite to one another and attached to one another by the U-shaped retention element <NUM>, preferably comprising two sets of two retention flanges 4a, both sets being arranged rotated with respect to each other, preferably <NUM>°.

These embodiments, i.e., embodiments in which the main body <NUM>' comprises both the head <NUM> and the appendage <NUM>, are particularly advantageous when the hole <NUM> in the concrete wall <NUM> has a narrow frustoconical opening <NUM>'. As the person skilled in the art knows, the protective kit of the transverse bolt of the manufacturing process of a concrete wall can comprise a central cylindrical segment (cylindrical protective tube made of plastic) to which there is added at each end a frustoconical element made of plastic which is removed once the concrete is set. The hole <NUM> generated in the concrete wall <NUM> will therefore have two frustoconical openings <NUM>' (made of concrete) arranged at the ends of the hole <NUM> between which there is arranged a cylindrical segment <NUM>" (made of plastic if the protective tube has not been removed, or made of concrete if said protective tube has been removed), as can be seen in <FIG>. Usually only one of the frustoconical openings <NUM>' of the hole <NUM>, the opening <NUM>' arranged in the exposed face 9a of the concrete wall <NUM>, is plugged, such that in the description reference will only be made to a hole <NUM> in which the opening <NUM>' is arranged in the exposed face 9a of the concrete wall <NUM>. However, if both openings are to be plugged, the same will be done at both ends of the hole <NUM>. <FIG> and <FIG> depict a hole <NUM> with a frustoconical opening <NUM>' (the second opening being omitted) to better understand the invention. Depending on the shape of the frustoconical opening <NUM>' of the hole <NUM> to be plugged, it will be appropriate to use one plug (without an appendage <NUM>) or the other (with the appendage <NUM>) to assure better securing of the plug. For example, in the event that the frustoconical segment of the opening <NUM>' of the hole <NUM> is narrow (not very deep), it is advisable to use the plugs <NUM> or <NUM> comprising the main body <NUM>' with the appendage <NUM> (according to any of its variants). Otherwise, i.e., if the frustoconical segment of the opening <NUM>' of the hole <NUM> to be plugged is deep enough, the plug <NUM> comprising the main body <NUM> without the appendage <NUM> and plugs <NUM> or 101which do comprise the appendage <NUM>, could be used.

In these embodiments, i.e., embodiments in which the main body <NUM>' comprises both the head <NUM> and the appendage <NUM>, the head <NUM> can be adjusted to the shape of the frustoconical opening <NUM>' of the hole <NUM> such that when said head <NUM> abuts with the bottom of the frustoconical opening <NUM>', the active surface 6a of the head is aligned with the exposed face 9a of the concrete wall <NUM>.

Furthermore, in this embodiment in which the main body <NUM>' comprises the head <NUM> and the appendage <NUM>, said head <NUM> and said appendage <NUM> form a single part.

<FIG> show another embodiment of the plug <NUM>, not being part of the invention, in which the only thing that changes with respect to the described plugs are the elastic retention means <NUM>. In this case, the main body <NUM>' comprises both the head <NUM> and the appendage <NUM> and the retention means <NUM> comprise a single hook comprising a single conical-shaped retention flange 4a, as can be seen for example in <FIG>. Said retention flange 4a is attached to a mast <NUM> arranged on its geometric axis, part of said mast <NUM> being embedded in the main body <NUM>', such that said mast <NUM> is arranged parallel to or aligned with the longitudinal axis X, the retention means <NUM> protruding axially from the main body <NUM>' in the insertion direction A. As can be seen in <FIG>, the retention means <NUM> of this embodiment resemble an open umbrella, the retention flange 4a forming an acute angle α with respect to the longitudinal axis X of the plug. For the purpose of improving adherence of the mast <NUM> in the main body <NUM>', said mast <NUM> can comprise at the end farthest away from the vertex <NUM> of the hook a stop <NUM> which is arranged preferably perpendicular to the mast <NUM>, as can be seen in <FIG>, thus improving the grip between the mast <NUM> and the main body <NUM>'.

Another variant of the plug <NUM>, not being part of the invention, shown in <FIG> differs from the plug <NUM> described above in the shape of the retention means <NUM>. The retention means <NUM> of this variant also comprise a single hook with a single retention flange 4a, but it is circular in this case. The retention flange <NUM> can be arranged perpendicular to the longitudinal axis X or inclined with respect to said longitudinal axis X. Said retention flange 4a is also attached to a mast <NUM> arranged on its geometric axis, part of said mast <NUM> being embedded in the main body <NUM>', such that said mast <NUM> is arranged parallel to or aligned with the longitudinal axis X, the retention means <NUM> protruding axially from the main body <NUM>' in the insertion direction A. When the plug <NUM> is introduced in the hole <NUM> to be plugged, the retention flange 4a is bent, the retention flange 4a being compressed inside the hole <NUM> to be plugged such that it exerts continuous pressure against the inner surface of the hole <NUM>.

To facilitate the bending of the circular retention flange 4a, the latter can optionally comprise at least one notch <NUM> arranged at the distal end of the retention flange 4a, said notch <NUM> preferably extending in a radial direction of said circular retention flange 4a. In the example of the plug <NUM> of <FIG>, the circular retention flange 4a comprises a plurality of radial notches <NUM> distributed uniformly along the peripheral circumference of the retention flange 4a.

Another variant of the plug <NUM>, not being part of the invention, shown in <FIG>, differs from the plugs <NUM>, <NUM> and <NUM> described above in the shape of the retention means <NUM>. The retention means <NUM> of this variant also comprise a single hook comprising a single retention flange 4a, but in this case, in the form of a frustoconical ring, such that it forms a perimetral skirt. The end having a smaller dimension of the retention flange 4a is attached to a support <NUM> in the form of a circular ring, at least part of said support <NUM> being embedded in the main body <NUM>'. Said support <NUM> is arranged transverse to the longitudinal axis X such that the retention means <NUM> protrude radially from the main body <NUM>', preferably from the appendage <NUM> of the main body <NUM>', as can be seen in <FIG>.

As shown in <FIG>, the retention flange 4a forms an acute angle α with respect to the longitudinal axis X of the plug. Furthermore, the free end of the retention flange 4a is still arranged at distance d from the longitudinal axis X of the plug <NUM>, as can be seen in <FIG>, said distance d being greater than the radius of the hole <NUM> in the concrete wall <NUM> to be plugged.

Another variant of the plug <NUM>, not being part of the invention, shown in <FIG>, differs from the plug <NUM> described above in the shape of the retention means <NUM>. The retention means <NUM> of this variant also comprise a single hook with a single retention flange 4a, but in the form of an annulus in this case, as can be seen in <FIG>, the annulus protruding radially from the main body <NUM>' of the plug <NUM>, preferably from the appendage <NUM>, such that the retention flange 4a is arranged perpendicular to the longitudinal axis X of the plug <NUM>. The free end of the retention flange 4a is still arranged at distance d from the longitudinal axis X of the plug <NUM>, as can be seen in <FIG>, said distance d being greater than the radius of the hole <NUM> in the concrete wall <NUM> to be plugged. In a variant shown in <FIG>, the annulus of the retention means <NUM> of the plug <NUM>' is arranged inclined with respect to said longitudinal axis X instead of being arranged perpendicular to the longitudinal axis X.

In this embodiment, it is not necessary for the retention means <NUM> to comprise an additional support to allow the attachment to the main body <NUM>' because part of the annulus, preferably the part having a smaller diameter, is embedded in the main body <NUM>', as can be seen in <FIG>. When the plug <NUM> is introduced in the hole <NUM> to be plugged, the retention flange 4a is bent, the retention flange 4a being compressed inside the hole <NUM> to be plugged, such that it exerts continuous pressure against the inner surface of the hole <NUM>.

To facilitate the bending of the retention flange 4a in the form of an annulus, it can optionally also comprise at least one notch <NUM> arranged at the distal end of the retention flange 4a. In the example of the plug <NUM> of <FIG>, the retention flange 4a comprises a plurality of radial notches <NUM> distributed uniformly along the peripheral circumference of the retention flange 4a. The notches <NUM> extend radially, as can be seen in <FIG>.

The retention means <NUM> of the described plugs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>', <NUM>" and <NUM> are embedded in the appendage <NUM> of the main body <NUM>', but they could optionally also be embedded in the head <NUM> of a main body <NUM> that does not comprise the appendage <NUM>, as can be seen in <FIG>, for example.

Unlike the embodiment of the plug <NUM> of <FIG> (which does not comprise the appendage <NUM>) in which the retention means <NUM> protrude axially from the main body <NUM>, in the plugs <NUM>' and <NUM>" of <FIG> the retention means <NUM> protrude from the main body <NUM> according to a direction perpendicular to the longitudinal axis X.

The retention means <NUM> of the plug <NUM>' of the embodiment of <FIG>, which are not part of the invention, comprise a single hook comprising a single retention flange 4a in the form of a frustoconical ring, such that it forms a perimetral skirt, as described for the plug <NUM> of <FIG>. The end having a smaller dimension of the retention flange 4a is attached to a support <NUM> in the form of a circular ring, at least part of said support <NUM> being embedded in the main body <NUM>'. Said support <NUM> is arranged transverse to the longitudinal axis X, the retention means <NUM> protruding from the main body <NUM> according to a direction perpendicular to the longitudinal axis X, as can be seen in <FIG>. In this case, the retention flange 4a forms an acute angle α with respect to the longitudinal axis X of the plug and the free end of the retention flange 4a is still arranged at distance d from the longitudinal axis X of the plug <NUM>', said distance d being greater than the radius of the hole <NUM> in the concrete wall <NUM> to be plugged.

The retention means <NUM> of the plug <NUM>" of the embodiment of <FIG>, which are not part of the invention, differs from the plug <NUM>' described above in the shape of the retention means <NUM>. As in the case of the plug <NUM> of <FIG>, the retention means also comprise a single hook with a retention flange 4a, but in this case in the form of an annulus, as can be seen in <FIG>, part of the annulus being embedded in the main body <NUM> and part of the annulus protruding from the head <NUM> of the main body <NUM> according to a direction perpendicular to the longitudinal axis X of the plug <NUM>", the retention flange 4a being arranged perpendicular to the longitudinal axis X of the plug <NUM>" in this case. The free end of the retention flange 4a is still arranged at distance d from the longitudinal axis X of the plug <NUM>", as can be seen in <FIG>, said distance d being greater than the radius of the hole <NUM> in the concrete wall <NUM> to be plugged.

In a variant not shown in the drawings, the annulus is arranged inclined with respect to said longitudinal axis X instead of being arranged perpendicular to the longitudinal axis X. When the plug <NUM>" is introduced in the hole <NUM> to be plugged, the retention flange 4a is bent, the retention flange 4a being compressed inside the hole <NUM> to be plugged, such that it exerts continuous pressure against the inner surface of the hole <NUM>.

To facilitate the bending of the retention flange 4a in the form of an annulus, it can optionally also comprise the notches <NUM> described above.

Optionally, in other variants of the embodiments comprising a hook with a single retention flange 4a protruding from the head <NUM> or from the appendage <NUM> according to a direction perpendicular to the longitudinal axis X, whether or not they comprise the notches <NUM>, or are arranged perpendicular or inclined with respect to said longitudinal axis X, the retention means <NUM> can comprise more than one hook, the retention flanges 4a of each hook being spaced apart from one another according to the direction of the longitudinal axis X. The free ends of the retention flanges 4a of the plurality of hooks can be arranged at the same distance d with respect to the longitudinal axis X, or said distance d can be increased as the retention flanges 4a approach the free end of the head <NUM> of the corresponding plug according to the direction opposite the insertion direction A. An example of these variants is shown in <FIG>.

In <FIG>, which corresponds with a plug <NUM>" of the type having a main body <NUM>' which comprises both the head <NUM> and the appendage <NUM>, the retention means <NUM> comprise three hooks, each hook with a retention flange 4a in the form of an annulus and protruding radially from the appendage <NUM> in this case. The retention flanges 4a are arranged parallel and spaced apart from one another according to the direction of the longitudinal axis X. In this example, the free ends of all the retention flanges 4a are arranged at the same distance d with respect to the longitudinal axis X.

<FIG> shows a section view of the plug <NUM> of the embodiment of <FIG> (embodiment in which the main body <NUM>' comprises the appendage <NUM>) introduced in the hole <NUM> to be plugged. As shown in said figure, the retention flanges 4a are compressed and exert continuous pressure against the inner surface of the hole <NUM> (against the inner surface of the cylindrical segment <NUM>" in this case), which pressure lasts over time. The shape of the retention flanges 4a before and after introducing the plug <NUM> in the hole <NUM> to be plugged can be seen in <FIG> and <FIG>. As shown in <FIG>, the appendage <NUM> (according to any of its variants) is arranged inside the cylindrical segment <NUM>" of the hole <NUM> in the concrete wall <NUM>. In this case, the distance d of the retention flanges 4a with respect to the longitudinal axis X of the plug <NUM> before introducing the plug <NUM> in the hole <NUM> is greater than the radius of the cylindrical segment <NUM>" of the hole <NUM> in the concrete wall <NUM>. If the plug of the invention is retained in the frustoconical opening <NUM>' of the hole <NUM> by the retention flanges 4a, for example of the plug <NUM> of the embodiment without the appendage <NUM>, then the distance d of the retention flanges 4a with respect to the longitudinal axis X of the plug <NUM> before introducing said plug <NUM> in the hole <NUM> is greater than the radius of an annular portion of the frustoconical opening <NUM>', which portion corresponds with the position of the plug <NUM> in which it is aligned with the concrete wall <NUM>.

Claim 1:
Plug for closing a hole in a concrete wall, comprising a main body (<NUM>; <NUM>') and elastic retention means (<NUM>), the retention means (<NUM>) being partially embedded in the main body (<NUM>; <NUM>'),
wherein said retention means (<NUM>) comprise at least one set of two hooks arranged diametrically opposite to one another and at least partially projecting from the main body (<NUM>; <NUM>'), said hooks being configured for cooperating with the hole (<NUM>) of the concrete wall (<NUM>) for retaining the plug (<NUM>; <NUM>; <NUM>) in said hole (<NUM>), each hook comprising a respective retention flange (4a), the free end of the flange (4a) being at a distance (d) from a longitudinal axis (X) of the plug (<NUM>; <NUM>; <NUM>), said distance (d) being greater than the radius of the hole (<NUM>) of the concrete wall (<NUM>) to be plugged, such that, in use, with the plug (<NUM>; <NUM>; <NUM>) being arranged inside the hole (<NUM>) to be plugged, the flange (4a) is compressed inside the hole (<NUM>),
characterized in that the two retention flanges (4a) are attached to one another by a U-shaped retention element (<NUM>), part of said retention element (<NUM>) being embedded in the main body (<NUM>; <NUM>').