EXPANDABLE ANKLE WITH ANTI-ROTATIONAL PROPERTIES

Abstract

EXPANSION ANCHOR WITH ANTI-ROTATIONAL PROPERTIES The invention relates to an expansion anchor (T) for use in mounting thermal insulation panels on a wall, the anchor (T) having anti-rotation wings (3) that clamp the thermal insulation panels to prevent relative rotation of the anchor (T) with respect to the thermal insulation panel. Figure to be published with the abstract: Figure 1

Description

Title of the invention: EXPANDABLE ANKLE WITH ANTI-ROTATIONAL PROPERTIES

[0001] The present invention relates to an expandable dowel or anchor, preferably for building insulation, with anti-rotational properties.

[0002] Thermal insulation is increasingly applied to building facades, consisting of prefabricated panels with thermal insulation materials and allowing to significantly reduce the heat losses to which buildings are normally subjected through the exterior walls.

[0003] The thermal insulation panels are placed against a masonry wall of the building, and then holes are drilled in these panels, passing through the panel and reaching the wall. Expandable anchors are used to fix the thermal insulation panels to the wall.

[0004] Such an anchor comprises a head and a stem protruding from the head. The stem has an axial channel and longitudinal fins of the expanding type. A screw is screwed into the channel of the stem so as to cause expansion of the longitudinal fins, which then tighten into the hole in the wall.

[0005] Such a dowel has the disadvantage that, when the screw is being tightened, it tends to rotate uncontrollably relative to the thermal insulation panel.

[0006] In particular, this tendency for uncontrolled rotation of the anchor occurs during the final screwing phase, when the static friction between the thermal insulation panel and the anchor head is insufficient due to the brittleness of the panel's thermal insulation material. Such uncontrolled rotation of the anchor relative to the panel compromises the stability and correct positioning of the anchor.

[0007] The object of the present invention is to overcome the disadvantages of the prior art by creating a dowel having anti-rotational capabilities, such that it is not subject to any uncontrolled rotation relative to the thermal insulation panel, during the screwing of the screw into the dowel.

[0008] Another objective is to provide such an anchor whose structure is simpler and more functionally practical.

[0009] These objectives have been achieved by means of the present invention, which relates to an expanding anchor for fixing a panel to a wall by means of a screw having a head and a threaded shank, said anchor comprising: a head having a central hole, an external surface intended to be oriented outwards, and an internal surface intended to butt against the panel applied to the wall; a shank which protrudes from the internal surface of the head and is intended to be placed in a through hole obtained in said panel and in a hole obtained in said wall, said rod having a proximal section having a conduit communicating with said central hole of the head and a distal section having a conduit communicating with said conduit of the proximal section, said distal section having notches defining deformable fins, said conduit of the proximal section having a diameter greater than that of the conduit of the distal section, such that the head of the screw is able to be inserted into said conduit of the proximal section of the rod and that the rod of the screw is able to be screwed into the conduit of the distal section of the rod so as to cause a spreading and expansion of the deformable fins of the anchor which come into contact with said hole in the wall;and at least one anti-rotation fin projecting outwards from said proximal section of the stem to clamp said panel inside the hole in the panel, preventing rotation of the dowel relative to the panel during screw tightening of the screw.

[0010] According to an advantageous embodiment, said at least one anti-rotation fin is a radial fin that protrudes radially from the proximal section of the rod.

[0011] According to an advantageous embodiment, said at least one anti-rotation fin is connected to the internal surface of the head and has a tapered end portion oriented in the direction of the distal section of the rod.

[0012] According to an advantageous embodiment, said at least one anti-rotation fin extends lengthwise beyond a connecting portion between the proximal and distal sections of the rod.

[0013] According to an advantageous embodiment, said distal section of the stem has a wavy external surface.

[0014] According to an advantageous embodiment, said corrugated external surface of the distal section of the stem comprises a network of ribs.

[0015] According to an advantageous embodiment, said external surface of the head has knurling.

[0016] According to an advantageous embodiment, said peg comprises a cylindrical cap suitable for being placed in said central hole of the head.

[0017] According to an advantageous embodiment, said peg comprises at least one longitudinal rib disposed on the external surface of the distal section of the stem, between said at least one anti-rotation fin and said corrugated surface of the distal section of the stem.

[0018] According to an advantageous embodiment, said peg has a monolithic structure in which the head, the stem and said at least one anti-rotation fin are made in one piece, by injection molding of plastic material.

[0019] According to an advantageous embodiment, the ankle comprises four anti-rotation wings arranged equidistant at 90° to each other.

[0020] For clarity, the description refers to the attached drawings, which are for illustrative purposes only and are not exhaustive, in which:

[0021] [Fig. 1] is an axonometric representation of the ankle according to the present invention;

[0022] [Fig. 1 A] is a side view of the ankle of [Fig. 1];

[0023] [Fig.2] is a plan view of the internal surface of the head of the ankle of [Fig. 1];

[0024] [Fig.3] is a plan view of the external surface of the head of the ankle of [Fig.1];

[0025] [Fig.4] is a schematic, cross-sectional drawing which represents a first way to use the ankle of the present invention.

[0026] [Fig.5] is another schematic, cross-sectional drawing, which represents the first way to use the ankle of the present invention.

[0027] [Fig.6] is a schematic, cross-sectional drawing, which represents a second way different from using the ankle of the present invention.

[0028] [Fig.7] is another schematic, cross-sectional drawing, which represents the second way to use the ankle of the present invention.

[0029] With reference to [Fig.1], an anchor according to the present invention is described, globally indicated by the reference T.

[0030] The T-shaped anchor has a monolithic structure made by molding plastic materials.

[0031] The T-shaped ankle comprises:

[0032] - a head 1; and

[0033] - a rod 2 which protrudes from the head.

[0034] The head 1 has the shape of a circular plate, having a central hole la, located in the center. The head 1 has an external surface le intended to be oriented outwards and an internal surface 1b intended to be oriented towards a thermal insulation panel PT which is to be fixed to a wall M.

[0035] The rod 2 has a cylindrical tubular shape. The rod 2 projects from the inner surface 1b of the head 1, corresponding to the hole la of the head. The rod 2 has a proximal section 2a having a conduit 25 communicating with the central hole la of the head and a distal section 2b having a conduit 26 communicating with the conduit 25 of the proximal section of the rod. The conduit 25 of the proximal section of the rod has a larger diameter than the conduit 26 of the distal section of the rod.

[0036] The distal section 2b of the stem has longitudinal notches 2c which generate deformable fins 20 capable of deforming and extending outwards.

[0037] With reference to Figures 4 to 7, a thermal insulation panel PT is shown applied to a masonry wall M. A through hole Fl is made in the thermal insulation panel PT, which extends into a hole F2 in the wall M.

[0038] The rod 2 is inserted into the through hole Fl in the thermal insulation panel and extends to the hole F2 in the wall M. In particular, the dowel T is pushed into the holes Fl, F2 in the panel and the wall, until the head 1 of the dowel comes into contact with the thermal insulation panel PT. The head 1 of the dowel then acts as a stop flange.

[0039] At this stage, a screw V is inserted into the hole la of the head. The screw V has a head V1 with a diameter equal to the diameter of the conduit 25 of the proximal section 2a of the stem 2 of the peg T and a threaded stem V2, suitable for being screwed into the conduit 26 of the distal section 2b of the stem 2.

[0040] During screwing of the screw V, the head VI of the screw rests on a lower part of the conduit 25 of the proximal section 2a of the shank 2 of the dowel T, while the shank V2 of the screw is screwed into the conduit 26 of the distal section 2b of the shank 2 of the dowel, progressively causing a bulge or a twist of the deformable fins 20 of the distal section 2b of the shank inside the hole F2 of the wall M.

[0041] As anticipated, in known dowels, it can happen that the rotation of the screw is transmitted unfavorably to the dowel, causing the dowel to rotate relative to the panel. To prevent such rotation of the dowel, the dowel T has at least one anti-rotation fin 3 that projects outwards from the proximal section 2a of the shank 2 to clamp the panel PT in the hole Fl of the panel, preventing rotation of the dowel relative to the panel PT during the tightening of the screw V.

[0042] Advantageously, said at least one anti-rotation fin 3 is a radial fin projecting radially from the shaft 2. Advantageously, there are four anti-rotation fins 3, equidistant angularly from each other at 90° intervals. Each anti-rotation fin 3 has an end portion tapering towards the distal section 2b of the shaft 2.

[0043] The anti-rotation fins 3 are connected to the internal surface 1b of the head 1 of the ankle T and extend lengthwise beyond a connection point 2d between the proximal section 2a and the distal section 2b of the tubular rod 2.

[0044] When the T dowel is forcibly inserted into the Fl, F2 holes in the panel and the wall, the anti-rotation fins 3 cut the PT thermal insulation panel and are firmly embedded in a thickness of the PT panel, exploiting the friability of the panel structure.

[0045] Consequently, the four anti-rotation fins 3 are able to provide an anti-rotation anchoring function inside the thermal insulation panel PT, so as to prevent the risk of the dowel T being subjected to uncontrolled rotation inside the hole Fl of the panel, during the screwing of the screw V.

[0046] It should be noted that said pin T has a monolithic structure in which the head 1, the stem 2 and said at least one anti-rotation fin 3 are made in one piece, by injection molding of plastic material.

[0047] The peg T also includes a cap 4 suitable for being inserted into the central hole la of the head 1 to obstruct said central hole la and give perfect flatness to the external surface le of the head 1.

[0048] To ensure that the anchor T can have a greater grip inside the hole F2 in the wall, the distal section 2b of the rod 2 has a corrugated surface 2e, suitable for creating strong friction, and therefore greater tensile strength, in the hole F of the wall M.

[0049] In the preferred embodiment illustrated in the accompanying Figures, the corrugated surface 2e of the distal section 2b of the stem comprises a network of longitudinal and transverse ribs.

[0050] With reference to [Fig.3], the external surface of the head 1 has a knurling FZ designed to facilitate gripping with a layer of plaster generally intended to cover the external surface of the PT thermal insulation panel.

[0051] With reference to Figures 4 to 7, the possible methods of installation and operation of the T-anchor are illustrated.

[0052] In particular, Figures 4 and 5 show the installation phases of the T-anchor in the presence of a wall made of perforated bricks.

[0053] Figure 4 shows the initial installation procedure for the anchor T. The head 1 is butted against the outer surface of the thermal insulation panel PT. The proximal section 2a of the shank 2 is placed in the hole Fl of the thermal insulation panel PT. The anti-rotation fins 3 of the anchor are driven into the thermal insulation panel PT. The distal section 2a of the shank 2 is placed in the hole F2 of the wall M made of perforated bricks. The screw V is partially inserted into the shank 2 of the anchor T, but is not yet fully tightened.

[0054] Figure 5 shows the methods used to perform the final installation of the anchor T. The head VI of the screw rests on the bottom of the channel 25 of the proximal section 2a of the shank 2. The shank V2 of the screw V is screwed into the channel 26 of the distal section 2b of the shank 2, causing a twisting of the fins 20 of the distal section 2b of the shank. Tightening the screw V generates a rearward pull, in the axial direction, of the distal section 2b of the shank 2, with a deformation of the fins 20 of the distal section of the shank which generates a thickening C inside the hole in the perforated brick of the wall. This thickening C ensures a stable locking of the anchor T by interaction with the perforated brick. Finally, the closing cap 4 is inserted into the central hole la of the head 1.

Claims

Demands

1. Expanding anchor (T) for fixing a panel (PT) to a wall (M), by means of a screw (V) having a head (VI) and a threaded shank (V2), characterized in that said anchor (T) comprises: - a head (1) having a central hole (la), an external surface (le) intended to be turned outwards, and an internal surface (1b) intended to butt against the panel (PT) applied to the wall (M); - a shank (2) which protrudes from the internal surface (1b) of the head (1) and is intended to be placed in a through hole (Fl) obtained in said panel (PT) and in a hole (F2) obtained in said wall (M); said stem (2) having a proximal section (2a) having a conduit (25) communicating with said central hole (la) of the head (1) and a distal section (2b) having a conduit (26) communicating with said conduit (25) of the proximal section (2a); said distal section (2b) having notches (2c) defining deformable fins (20);said conduit (25) of the proximal section (2a) having a larger diameter than that of the conduit (26) of the distal section (2b), such that the head (VI) of the screw (V) is suitable for insertion into said conduit (25) of the proximal section (2a) of the shank (2) and the shank (V2) of the screw (V) is suitable for screwing into the conduit (26) of the distal section (2b) of the shank (2) so as to cause spreading and expansion of the deformable fins (20) of the dowel (T) which engage in said hole (F2) of the wall (M), and - at least one anti-rotation fin (3) which projects outwards from said proximal section (2a) of the shank (2) to clamp said panel (PT) inside the hole (F1) of the panel (PT), preventing rotation of the dowel (T) relative to the panel (PT) during tightening the screw (V).;

2. Peg (T) according to claim 1, characterized in that said at least one anti-rotation fin (3) is a radial fin which protrudes radially from the proximal section (2a) of the stem (2).

3. Peg (T) according to claim 1 or 2, characterized in that said at least one anti-rotation fin (3) is connected to the internal surface (1b) of the head (1) and has a tapered end portion oriented in the direction of the distal section (2b) of the shank (2).

4. Peg (T) according to any one of the preceding claims 1 to 3, characterized in that said at least one anti-rotation fin (3) extends lengthwise beyond a connecting portion (2d) between the proximal section (2a) and the distal section (2b) of the stem (2).

5. Peg (T) according to any one of the preceding claims 1 to 4, characterized in that said distal section (2b) of the shank (2) has a wavy external surface (2e).

6. Peg (T) according to claim 5, characterized in that said corrugated external surface (2e) of the distal section (2b) of the stem (2) comprises a network of ribs.

7. Peg (T) according to any one of the preceding claims 1 to 6, characterized in that said external surface (le) of the head (1) has a knurling (FZ).

8. Peg (T) according to any one of the preceding claims 1 to 7, characterized in that said peg (T) comprises a cylindrical cap (4) suitable for being placed in said central hole (la) of the head (1).

9. Peg (T) according to any one of the preceding claims 1 to 8, characterized in that said peg (T) comprises at least one longitudinal rib (5) disposed on the external surface of the distal section (2b) of the stem (2), between said at least one anti-rotation fin (3) and said corrugated surface (2e) of the distal section (2b) of the stem (2).

10. An anchor (T) according to any one of the preceding claims 1 to 9, characterized in that said anchor (T) has a monolithic structure in which the head (1), the shank (2) and said at least one anti-rotation fin (3) are made in one piece, by injection molding of plastic material.

11. Peg (T) according to any one of the preceding claims 1 to 10, characterized in that it comprises four anti-rotation fins (3) arranged equidistant at 90° to each other.

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