FIELD OF THE INVENTION

The present invention concerns a wall attachment device, in particular an attachment or anchoring device of the so-called“hold down” type.

In particular, the attachment device in accordance with the present invention is installed during the construction of an anti-seismic building or following a seismic adaptation of a building as a precautionary measure against possible earthquakes.

BACKGROUND OF THE INVENTION

A number of anti-seismic attachment devices are known which securely connect together walls, panels, floors or a combination thereof. These attachment devices have the purpose of preventing the displacement and therefore the possible collapse of walls, panels or suchlike in a building during a seismic event.

In the construction of buildings, different types of attachment devices are known. There are vertical and horizontal attachment devices for connecting wooden panels together, and connecting a concrete floor with a wooden wall or combinations thereof.

In particular, a device is known, a so called“hold down” device, for attaching a panel, or a pillar, to a support plane, the device being provided with a base plate which can be selectively anchored to the support plane, and with a connection plate, attached transversely and integrally to the base plate, connected during use to the panel. The base plate is connected to the support plane, for example a concrete floor, by means of chemical or mechanical attachments, for example screws, and the connection plate is connected to the panel, for example a wooden wall, or a pillar, or other similar or comparable element, by means of mechanical attachments, such as a plurality of threaded or through elements. The base plate and the connection plate are integral with each other and reciprocally disposed in an L- shape.

Examples of this solution can be found in US 5,467,570 and GB 2 376 029.

This known solution is, however, extremely rigid, not flexible and does not guarantee a safe anti-seismic protection since a high stress can cause the base plate to yield with consequent damage to the support plane and/or deform the attachment screws between the connection plate and the panel.

In particular, the mechanical attachments which attach the connection plate to the wooden panel, for example the screws, do not adequately support the seismic load, causing serious problems, such as mainly:

- the tearing of the seatings of the screws in the wooden panel with consequent damage to the panel;

- the breaking of the shear head screws with consequent failure of the attachment device.

Consequently, the support plane and the panel which are constrained to the attachment device can be ruined or damaged under seismic stress, resulting in considerable economic damage for restructuring.

Furthermore, in the worst case, known attachment devices may not fully withstand the seismic stress and yield until breaking, or the mechanical or chemical attachments may fail causing the panel to fall and thus endangering the occupants of the building.

It is one purpose of the present invention to provide an attachment device of the type indicated above which prevents the detachment of the base plate from the support plane and/or of the connection plate from the panel.

It is in particular a purpose of the present invention to provide an attachment device that can yield in a well-defined zone of the connection plate before upsetting phenomena occur in the seatings of the screws in the wooden panel, with consequent damage to the panel, and before the breakage of the anchoring elements to the panel occurs with consequent failure of the attachment device.

It is also a purpose of the present invention to provide an attachment device which has high ductility and guarantees anti-seismic protection without ruining and damaging walls, panels, pillars, planes or suchlike to which the device itself is connected.

It is also a purpose of the present invention to provide an attachment device which guarantees greater safety during a seismic event.

It is also a purpose of the present invention is to provide an attachment device with a greater capacity to absorb loads of a seismic nature.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claim. The dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, a wall attachment device, in particular of a panel to a support plane, according to the present invention comprises:

- a base plate which can be positioned on the support plane and selectively anchored thereto,

- a connection plate located transversely and integrally attached to the base plate and on which the panel is positioned during use.

The connection plate develops longitudinally, during use, substantially orthogonal to the base plate.

According to one aspect of the invention, the connection plate comprises:

- a first portion, or lower portion, to which at least the base plate is connected;

- a second portion, or upper portion, provided with a plurality of attachment elements of the panel;

- an intermediate yield portion interposed between the first portion and the second portion and provided with at least one zone with a reduced section with respect to the first and second portion, the intermediate portion having a longitudinal extension comprised between about 0.4 and 0.9 times the longitudinal extension of the first portion.

Advantageously, the present attachment device has, thanks to the reduced section zone and to its longitudinal size with respect to the other portions, in particular with respect to the first lower portion, a greater flexibility and compliance in the intermediate yield portion with respect to the other two portions of the connection plate. In fact, the attachment device, if mechanically stressed, for example during a seismic event, can deform and yield only in the intermediate yield portion, preventing damage or breakage of the anchoring elements provided for the attachment of the panel to the attachment device, or of the anchoring elements provided for the attachment of the base plate to the support plane.

The possibility that the intermediate yield portion is able to elastically deform, and possibly yield, allows it, during for example a seismic event, to be able to absorb the stresses that are induced, preventing a structural failure of the entire panel, with obvious safety risks for people and objects.

This therefore prevents, for example, phenomena of damage to the wooden panel, such as upsetting or similar phenomena.

Furthermore, the reduced section zone of the intermediate portion, by absorbing the energy of the seismic stresses, prevents the latter from deforming the first portion and the second portion and, therefore, prevents the detachment of the base plate from the support plane and/or of the connection plate from the panel. Consequently, the panel and/or the support plane connected to the attachment device according to the present invention are not ruined or damaged and at the same time the security and the anti-seismic protection of the building are maintained and increased.

ILLUSTRATION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is a three-dimensional view of two wall attachment devices according to the present invention in condition of use;

- fig. 2 is a three-dimensional view of a variant of the attachment device of fig. 1 ;

- fig. 3 is a three-dimensional view of another variant of the attachment device of fig. 1.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DESCRIPTION OF EMBODIMENTS

We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

With reference to the drawings, a wall attachment device 10, in particular to attach a panel 11 to a support plane 12, comprises:

- a base plate 14 which can be positioned on the support plane 12 and selectively anchored thereto; the base plate 14, during use, is normally disposed on a horizontal plane defined by the support plane 12;

- a connection plate 15 located transversely and integrally attached to the base plate 14 and on which the panel 11 is positioned during use; the connection plate 15, during use, is normally disposed on a vertical plane defined by the panel 11.

According to one embodiment, the support plane 12 can be a floor made of concrete, reinforced concrete or suchlike.

According to one embodiment, the panel 11 can be a wall made of wood, plywood, chipboard or suchlike, or a pillar, a beam, or other similar or comparable structural element.

According to one embodiment, the base plate 14 can be disposed in an L shape, that is, orthogonal with the connection plate 15.

According to another embodiment, the base plate 14 can have a substantially square or rectangular shape.

According to one embodiment, the sides of the base plate 14, located during use perpendicular to the connection plate 15, have a length S comprised between 5 cm and 15 cm, preferably between about 7cm and 10cm.

According to one embodiment, the base plate 14 can be provided with at least one anchoring element 13 configured to allow the anchoring of the base plate 14 to the support plane 12.

The anchoring element 13 can be a through hole made in the base plate 14 and in which a mechanical attachment means, in this case a screw 18, is inserted which is anchored to the support plane 12 for example by screwing and/or by means of chemical substances.

According to one embodiment, the base plate 14 and the connection plate 15 can have a thickness comprised between 2 mm and 6 mm, preferably comprised between 3 mm and 5 mm.

In accordance with a possible solution, the attachment device 10 can comprise at least one attachment rib 16 integrally attached between the base plate 14 and the connection plate 15 and located transversely thereto.

In accordance with a possible solution, the rib 16 is attached in correspondence with the lateral edges of the base plate 14 and of the connection plate 15.

The attachment device 10 can be provided with two opposite ribs 16 attached on opposite lateral edges of the base plate 14 and of the connection plate 15.

According to one embodiment, the rib 16 can have a triangular shape.

According to another embodiment, the rib 16 can be provided with an end portion 16a overlapping, during use, the base plate 14. This end portion 16a can be obtained by bending to about 90° the plate defining the rib 16. Furthermore, the end portion 16a is provided with a through hole 13a coaxial to the anchoring element 13 defined above of the base plate 14. This solution allows to securely constrain the at least one rib 16 to the base plate 14 by means of, for example, the tightening screw 18.

According to one embodiment, the rib 16 can be welded to the base plate 14 and to the connection plate 15 by means of welding seams 32.

According to one embodiment, the at least one end portion 16a of the rib 16 can have welding seams 32 for attachment to the base plate 14.

According to one embodiment, the connection plate 15 has an oblong development along an axis Z perpendicular to the support plane 12, that is, to the base plate 14.

According to one embodiment, the connection plate 15 can have a size in height H along the axis Z comprised between 25cm and 140cm, preferably between 50 cm and 90 cm.

According to one embodiment, on the base plate 14 there can be positioned at least one reinforcement plate 17 integrally attached to the latter and to the support plane 12 by means of the mechanical attachment mean as above, that is, the screw 18. The reinforcement plate 17 increases and better distributes the load of the base plate 14 itself on the support plane 12.

According to one aspect of the present invention, the connection plate 15 comprises a first portion 19, or lower portion, to which at least the base plate 14 is connected, and a second portion 21 , or upper portion, provided with a plurality of attachment elements 25 configured to allow the attachment of the panel 11.

According to a possible embodiment, the connection plate 15 has a uniform thickness along its longitudinal extension, and the first portion 19 and the second portion 21 have the same width L.

By way of example only, the first portion 19 and the second portion 21 have a width L comprised between 5cm and 15cm, preferably about 7cm and 12cm.

According to one embodiment, the attachment elements 25 can comprise through holes in which screws 26 or nails are inserted for the attachment to the panel 11.

According to one embodiment, the through holes of the panel 11 as above can be disposed in parallel rows.

According to one embodiment, the through holes of the panel 11 as above can be disposed on at least two columns symmetrical with respect to the axis Z.

According to one embodiment, the through holes of the panel 11 as above can be disposed in sequences of two holes aligned parallel to the support plane 12 followed along the axis Z by three holes aligned parallel to the support plane 12.

According to one aspect of the present invention, the connection plate 15 is provided with an intermediate yield portion 20, interposed between the first portion 19 and the second portion 21 and provided with at least one reduced section zone 27.

In particular, the reduced section zone 27 defines a reduction in the resistant cross-section of the connection plate 15 comprised between 15% and 50%, preferably between 30% and 50% with respect to the first portion 19 and second portion 21 of the connection plate 15.

The reduced section zone 27, in fact, determines a reduction in the overall section or width of the intermediate yield portion 20 with respect to the width of the first portion 19 and of the second portion 21 of the connection plate 15. Therefore, the intermediate yield portion 20 is more compliant and flexible than the other portions 19 and 21 and allows a certain deformation of the attachment device 10.

The reduced section zone 27 has a longitudinal extension E that develops along the axis Z.

In accordance with some embodiments, the rib 16 is connected only to the first portion 19, and does not affect the intermediate yield portion 20 and the second portion 21.

According to one embodiment, the first portion 19, the intermediate yield portion 20 and the second portion 21 are integral with each other and aligned, one after the other, along the axis Z.

The first portion 19, the intermediate yield portion 20 and the second portion 21 can all lie on a common lying plane.

The first portion 19 and the second portion 21 have respectively a first size D1 and a second size D2 determined in a direction parallel to the axis Z.

The longitudinal extension E of the at least one reduced section zone 27 is comprised between about 0.4 and 0.9 times the first size D1 of the first portion 19. In this way, the reduced section zone 27 prevents, in case of seismic event, but not only, the first portion 19 and the second portion 21 from deforming under the action of an external stress, and at the same time guarantees the correct resistance of the reduced section zone 27 to said external stress.

According to a possible solution, the second size D2 of the second portion 21 can be comprised between 1 and 10 times the longitudinal extension E of the at least one a reduced section zone 27.

According to one embodiment, the reduced section zone 27 is defined by at least one concavity 28 made on at least one lateral edge 30 of the intermediate yield portion 20, which defines a reduction in width of the intermediate yield portion 20 with respect to the first portion 19 and to the second portion 21.

According to one embodiment, the concavity 28 can have a maximum depth comprised between 2 mm and 25 mm, preferably between 4 and 16 mm.

According to one embodiment, with reference to figs. 1-3, the reduced section zone 27 is defined by two concavities 28 made on the opposite lateral edges 30 of the intermediate yield portion 20.

According to one embodiment, with reference to fig. 2, the reduced section zone 27 comprises at least one slot 29 passing through the thickness of the intermediate yield portion 20 and having a longitudinal extension parallel to the axis Z.

According to one embodiment, the slot 29 can have a maximum width, comprised between 2 mm and 10 mm, preferably comprised between 3mm and 8mm.

According to one embodiment, with reference to fig. 3, the intermediate yield portion 20 comprises two slots 29 passing through the thickness of the intermediate yield portion 20 and made in a symmetrical position with respect to the axis Z.

In accordance with possible solutions, the intermediate yield portion 20 can comprise a plurality of slots 29 distanced with respect to each other.

The one or more slots 29 made in the intermediate yield portion 20 have a longitudinal extension parallel to the axis Z.

According to one embodiment, the at least one slot 29 has a longitudinal extension parallel to the axis Z substantially equal to the longitudinal extension E of the reduced section zone 27. In this way, the slot 29 allows to increase the section reduction more in the reduced section zone 27 than in the first portion 19 and second portion 21.

In fact, the reduced section zone 27 advantageously reduces the cross-section of the intermediate yield portion 20 reducing the width thereof with respect to the width L of the first portion 19 and of the second portion 21. In this way, the reduced section zone 27 defines a zone of the connection plate 15 which is more flexible and more compliant than the plates of the attachment devices of the state of the art. In fact, the attachment device 10 in accordance with the present invention has a greater capacity to absorb the load by exploiting the elastic compliance of the intermediate yield portion 20 following, in particular, the reduction in cross-section as above.

The intermediate yield portion 20 yields and deforms under the seismic stress absorbing its energy and preventing the panel 11 from falling or being displaced without deforming, breaking or damaging the anchoring elements 13 and/or the attachment elements 25, and consequently safeguarding the integrity of the support plane 12 and/or of the panel 11.

According to one embodiment, the reduced section zone 27 can advantageously be free of sharp edges so as to prevent the concentration of stresses in these edges and, therefore, the breakage of the intermediate yield portion 20.

For this purpose, the concavity 28 can be provided with connection portions 31 which connect the intermediate yield portion 20 with the first portion 19 and/or with the second portion 21.

By way of example only, the connection portions 31 can have a radius R of curvature comprised between 5 mm and 9 mm.

According to one embodiment, the slot 29 can have substantially a rectangular shape with rounded ends.

According to another embodiment, with reference to fig. 1, a panel 11 can have at least two attachment devices 10 attached to the corresponding ends of the panel 11 itself in order to anchor it securely to the support plane 12 above all in the case of seismic stress. For example, during a seismic stress the panel 11 could be stressed in a cyclical manner, for example one of the ends of the panel 11 could be pushed upward along the axis Z away from the support plane 12 and the opposite end downward against the support plane 12 and vice versa until the seismic phenomenon ends. The presence of at least one attachment device 10 for each end of the panel 11 guarantees the secure anchoring of the panel 11 to the support plane 12 during the cyclic seismic phenomenon as above.

It is clear that modifications and/or additions of parts may be made to the attachment device 10 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of attachment device 10, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.