ANTI-SEISMIC ISOLATOR OF THE SLIDING PENDULUM TYPE FOR PROTECTING CONSTRUCTIONS

Abstract

 An anti-seismic isolator of the sliding pendulum type (1) for protecting constructions, comprising a lower plate (2) adapted to be arranged close to a foundation structure, an upper plate (3) arranged above the lower plate (2) along a linear axis (Y) and adapted at least to contribute to supporting an elevated structure to dissipate the kinetic energy transmitted to the elevated structure by a natural phenomenon or by a human-caused event and provided with a high release of total energy, and a sliding and dissipation pad (4) arranged simply resting against the lower plate (2) and the upper plate (3) between which it is interposed to swing freely on the inner surface (2a, 3a) of the lower plate (2) and the upper plate (3) according to one or more random side directions, orthogonal to the linear axis (Y), alternately between an equilibrium position, assumed in absence of the natural phenomenon or the human-caused event, wherein the sliding and dissipation pad (4), the lower plate (2) and the upper plate (3) are substantially coaxial to each other, and a plurality of instability positions, assumed while the natural phenomenon or the human-caused event is in progress, wherein the sliding and dissipation pad (4), the lower plate (2) and the upper plate (3) are offset from each other, to dissipate the kinetic energy of the natural phenomenon or the human-caused event, transmitted to the elevated structure. In particular, the two outer faces (4a, 4b), axially opposite to each other along the linear axis (Y), of said sliding and dissipation pad (4) are coated with a laminar layer (5), which is made of thermosetting resin and is in direct contact with both at least one of the outer faces (4a, 4b) of the sliding and dissipation pad (4) and the inner surface (2a, 3a) of the lower plate (2) and/or of the upper plate (3).

Description

[0001] The present invention relates to the field of civil constructions and, more in detail, relates to an anti-seismic isolator of the so-called sliding pendulum type (single or double), used for the protection of constructions.

[0002] Substantially, the present invention relates to an anti-seismic isolator for protecting constructions, wherein the isolator has the form of a (single or double) sliding pendulum bearing, wherein the surface of the sliding and dissipation pad is coated with a laminar layer of thermosetting plastic material instead of thermoplastic plastic material as in the case in the prior art.

[0003] It is known that in the fields of civil engineering and architecture, the term "anti-seismic isolators" indicates support devices, which are used to isolate the load-bearing structure of the buildings, either structurally or physically, from the disruptive and often devastating effects of an abrupt and sudden natural event, such as an earthquake.

[0004] A particular type of dissipative anti-seismic isolators (or bearings) of known type, to which the present invention specifically refers, is called "sliding pendulum" in the basic variant, and "double sliding pendulum" in the more articulated variant; these anti-seismic isolators are also known in the industry by the acronym FPS, which stands for "Friction Pendulum System".

[0005] Such anti-seismic isolators are intended to be applied between the foundations (or foundation structure) of a civil structure (e.g. such as a building or bridge) and the civil structure (or elevated structure or superstructure) itself, to protect it from a seismic shock or a human-caused impacting or catastrophic event.

[0006] Among the anti-seismic isolators performing this function, there is the dissipative support device described in patent US4,644,714 A; it comprises a lower support (or anchor plate) and an upper support (or striker plate), integral respectively to the foundation structure and the elevated structure. Both such supports comprise a respective concave sliding surface, facing each other along a generally vertical linear axis, and are separated from each other by a sliding and dissipation pad (or lens or shoe) made of a plastic material.

[0007] In turn, the sliding and dissipation pad comprises two convex outer surfaces which are opposite to each other, in contact and mating with the concave sliding surfaces of the upper and lower supports of the anti-seismic isolator, to form a spherical articulation.

[0008] In the case of a simple sliding pendulum, the anti-seismic isolator incorporates a single sliding and dissipation pad, in contact with both the lower anchor plate and the upper striker plate, while in the case of a double sliding pendulum, the anti-seismic isolator incorporates two mutually coupled sliding pads, one in contact with the lower anchor plate and the other one in contact with the upper striker plate.

[0009] In the presence of an earthquake, the sliding and dissipation pad is thus free to slide with pendulum motion relative to the lower support (or anchor plate), protecting the superimposed structure from the potentially devastating, and in any case highly dangerous and risky effects of the earthquake.

[0010] The sliding and dissipation pad arranged simply resting on the lower and upper plates between which it is interposed, thus swings freely on the concave surface of the lower support plate and the upper support plate according to one or more random (but generally radial) side directions, orthogonal to the linear axis, alternately between a position of equilibrium, assumed in the absence of the aforesaid natural phenomenon or human-caused event, in which the sliding and dissipation pad, the anchor plate and the striker plate are substantially and coaxial to each other, and a plurality of positions of structural instability, assumed while the natural phenomenon or human-caused event is occurring, in which the sliding and dissipation pad, the lower support plate and the upper striker plate are offset from each other, to dissipate the kinetic energy of the natural phenomenon or human-caused event, transmitted to the elevated structure.

[0011] On the convex surface of the sliding and dissipation pad, the one in contact with the concave surface of the lower support and the upper support, a sliding material, in the form of a laminar layer or film, is usually applied to promote the relative sliding of the two surfaces.

[0012] A thermoplastic composite material comprising polytetrafluoroethylene (also known as PTFE) filled with reinforcing fillers, such as carbon fibers, glass fibers, bronze, or boron nitride is used as the sliding surface material of the pad, according to a known technique.

[0013] The sliding surface material has a high friction coefficient of up to 20%, which allows a high amount of energy to be dissipated during an oscillation, e.g. induced by an earthquake.

[0014] However, these anti-seismic isolation devices do not have a satisfactory resistance to wear and, for this reason, they are not adapted to be used to support elevated structures (such as bridges, in particular) that have continuous and frequent service movements also in the absence of an earthquake, e.g. by the effect of thermal expansion, wind action or sudden changes in the load supported by the elevated structures.

[0015] According to another known technique, e.g. found in EP1836404 A2 of the prior art, anti-seismic isolation devices of the sliding pendulum type have been suggested, which exploit a different type of sliding material.

[0016] In particular, according to EP1836404 A2, the sliding material may be pure polytetrafluoroethylene (PTFE), without reinforcing fillers, or ultra-high molecular weight polyethylene (also known by the acronym UHMWPE); these materials have a high wear resistance and a relatively low coefficient of friction, which makes them suitable for service movements of the elevated structures, but unsuitable for disposing of large amounts of energy, as is necessary in the event of a high-intensity earthquake.

[0017] Further examples of anti-seismic isolators of the sliding pendulum type (single or double) for protecting constructions already available on the market are patent documents JP6173639 B1 and CN106223508 B.

[0018] In anti-seismic isolation systems of the known type, in general, the aim is often to achieve the highest possible energy dissipation by damping, so that, in pendulum isolators of the known technique, this results in the maximum or best possible supply of friction, always using and drawing on particular thermoplastic resins inserted between the structural elements of the bearing device (or anti-seismic isolation). In this manner, the horizontal displacements of the elevated structure are reduced and those of the ground on which it rests are controlled, however without preventing the problems of wear described above.

[0019] A further problem of the sliding materials of the known technique is the rapid mechanical degradation due to the heat dissipated during the seismic event; in the presence of high sliding velocities - such as those generated by a high-intensity earthquake - as well as high coefficient of friction and prolonged duration of seismic excitation, the relative sliding of the surfaces of the pad on the inner surfaces of the support plates produces, in effect, enormous amounts of heat, which rapidly decay the properties of the sliding surface material of the sliding pad. Therefore, it is desirable at present, in the field of building and civil engineering, to have an anti-seismic support (or bearing) that is affected at least to a lesser degree by such a decay of the sliding and dissipation pad due to the effects of the heat produced by the sliding of the pad itself, without because of this having to give up the production of heat by friction, or the dissipation of the energy transmitted by the earthquake to the structure in elevation.

[0020] It is also desirable for the anti-seismic isolators of the so-called sliding pendulum type for protecting constructions to have a design that is as simplified as possible, especially concerning the crucial component that is constituted by the sliding and dissipation pad.

[0021] Therefore, starting from the awareness of the aforementioned drawbacks of the prior art, the present invention effectively suggests remedying them.

[0022] In particular, it is main purpose of the invention to provide an anti-seismic isolator, of the so-called sliding pendulum type, for protecting constructions, wherein the sliding and dissipation pad, while maintaining excellent dissipative efficiency and, therefore, a high friction coefficient, at least equal to those of the anti-seismic isolators of the prior art, has a significantly higher resistance to wear relative to the pad belonging to the latter.

[0023] In other words, it is primary purpose of the present invention to develop an anti-seismic isolator of the so-called sliding pendulum type for protecting constructions, which preserves the structural integrity of the sliding and dissipation pad unaltered for longer than equivalent isolators of the known technique.

[0024] It is a second purpose of the present invention to suggest an anti-seismic isolator of the so-called sliding pendulum type for protecting constructions, which is a significant and surprising innovation in the field of construction and civil engineering, which has always been focused on making anti-seismic isolators provided with sliding and dissipation pads having a high friction coefficient and, therefore, coated with a thermoplastic material.

[0025] Within the scope of the aforesaid purposes, it is task of the invention to disclose a dissipative anti-seismic isolator of the so-called sliding pendulum type for protecting constructions, which anti-seismic isolator, on the whole, possesses an effective functional life greater than that guaranteed by dissipative anti-seismic isolators of known types.

[0026] It is a further purpose of the present invention to make available an anti-seismic isolator of the sliding pendulum type for protecting constructions, which makes it possible to achieve a high dissipation without the decay of the sliding and dissipation pad caused by the heat produced and dissipated during the anti-seismic event, as happens instead in the isolators of the prior art more directly comparable thereto.

[0027] It is a last but not least purpose of the invention to provide a dissipative anti-seismic isolator of the sliding pendulum type for protecting constructions which, because of the ambitious aims listed above, maintains a reasonable production cost and competitive market prices.

[0028] Said purposes are achieved through a dissipative anti-seismic isolator of the sliding pendulum type for protecting constructions according to claim 1 appended hereto, as hereinafter referred for the sake of brevity of presentation.

[0029] Further constructional detail features of the anti-seismic isolator of the sliding pendulum type for protecting constructions of the invention are disclosed in the respective dependent claims.

[0030] The aforesaid claims, as hereinafter specifically and concretely defined, are an integral part of the present description.

[0031] Advantageously, the dissipative anti-seismic isolator of the sliding pendulum type for protecting constructions, object of the invention, has a lower wear level of the sliding and dissipation pad, interposed between the two support plates, than that of the isolators of the prior art equivalent thereto.

[0032] This is positively due to the fact that, in the dissipative anti-seismic isolator of the invention, at least one of the two outer faces (axially opposite to each other along the linear axis of the insulating device) of the sliding and dissipation pad is at least partially (although, preferably almost totally) coated with a laminar layer which is made of thermosetting resin and is in direct contact with both at least one of the outer faces of the sliding and dissipation pad and the inner surface of the lower plate and/or the upper plate.

[0033] Therefore, equally advantageously, the dissipative anti-seismic isolator of the sliding pendulum type of the invention maintains the structural integrity of the sliding and dissipation pad unchanged for longer than comparable isolators of the known technique.

[0034] Still advantageously, the dissipative anti-seismic isolator of the sliding pendulum type of the invention has less mechanical decay by effect of heat dissipation during the seismic event than the anti-seismic isolators of the prior art: this because the thermosetting material with which at least one of the two outer faces of the sliding and dissipation pad is at least partially coated provides an optimal compromise between friction coefficient and structural integrity without component wear, surprisingly also in the presence of operating conditions hitherto considered critical from the point of view of wear, especially of the sliding pad, such as high sliding speeds - and therefore anti-seismic events of high intensity - and prolonged duration of the anti-seismic excitation.

[0035] In an advantageously manner, therefore, the dissipative anti-seismic isolator of the present invention is a relevant innovation in the field of civil construction and a significant, unexpected step forward aimed at obtaining its longer functional life relative to the known technique, without this being to the detriment of its performance.

[0036] Said objects and advantages will be more evident from the description that follows, related to a preferred embodiment of the anti-seismic isolator of the sliding pendulum type for protecting constructions of the invention, given by way of indicative and non-limiting example, with the help of the attached drawings, where:

• figure 1 is a cutaway assonometric view of the dissipative anti-seismic isolator of the sliding pendulum type of the invention, in the equilibrium position;
• figure 2 is a plan view of figure 1;
• figure 3 is a view of figure 2 taken along section plane III-III.

[0037] The dissipative anti-seismic isolator of the sliding pendulum type, object of the present invention, useful for protecting constructions, is illustrated in its resting condition (or equilibrium position) in figure 1, where it is globally indicated with 1.

[0038] It is should be observed that the anti-seismic isolator of the sliding pendulum type 1 comprises:

• a lower plate 2, made of metallic material, such as steel, adapted to be arranged close to a foundation structure (also named substructure, not shown);
• an upper plate 3, also made of metallic material, such as steel, arranged above said lower plate 2 along a linear axis Y and adapted at least to contribute to supporting an elevated structure (also named superstructure, not shown) to dissipate the kinetic energy transmitted to the elevated structure itself by a natural phenomenon or by a human-caused event, in both cases however provided with a high release of total energy (or mechanical energy);
• and a sliding and dissipation pad (or shoe or lens) 4 made of metallic material (e.g. such as carbon filled steel) and arranged simply resting against the lower plate 2 and the upper plate 3 between which it is interposed so as to swing freely on the inner surface 2a, 3a respectively of the lower plate 2 and the upper plate 3 according to one or more random side directions, orthogonal to the linear axis Y, alternately between an equilibrium position (shown ,as mentioned, in figure 1) assumed in absence of the natural phenomenon or the human-caused event, wherein the sliding and dissipation pad 4, the lower plate 2 and the upper plate 3 are substantially and coaxial to each other, and a plurality of instability positions (not shown for the sake of simplicity of presentation), assumed while the natural phenomenon or the human-caused event is in progress, wherein the sliding and dissipation pad 4, the lower plate 2 and the upper plate 3 are offset from each other, to dissipate the kinetic energy of the natural phenomenon or the human-caused event, transmitted to the elevated structure.

[0039] According to the invention, in the specific case, both the outer faces 4a, 4b, axially opposite to each other along the aforesaid linear axis Y, of the sliding and dissipation pad 4 are entirely coated with a single laminar layer (or film) 5, which is made of thermosetting resin and is in direct contact, in this preferential case, with both the two outer faces 4a, 4b of the sliding and dissipation pad 4 and of the inner surface 2a, 3a of the lower plate 2 and of the upper plate 3.

[0040] Therefore, the anti-seismic isolator of the sliding pendulum type 1 of the invention has a constructional concept which is much simpler than that one of the anti-seismic isolators of the known type which are more similar and comparable thereto, shown for instance in prior art documents JP6173639 B1 and CN106223508 B, in which, indeed, the sliding surface material which is interposed between the sliding and dissipation pad and the lower plate as well as between the sliding and dissipation pad and the top plate is composite, multilayer, determining a clear constructive complication.

[0041] Furthermore, in these two prior art documents, the thermosetting resin laminar layer is not in simultaneous contact with at least one of the outer faces of the sliding pad and the inner surface of the lower plate and/or of the upper plate, as it happens, instead, appropriately in the anti-seismic isolator 1 of the invention, in such a way that the thermosetting resin laminar layer shown in JP6173639 B1 and CN106223508 B either does not perform at all or performs it much less effectively and with greater constructive complication the function intended by the only laminar layer 5 present in the anti-seismic isolator 1 of the invention.

[0042] It is stated precisely that, in general, a resin can be defined as a solid or semi-solid organic product of natural or synthetic origin, without a precise melting point and, generally, of high molecular weight. The main distinction that is made on an industrial level is between thermoplastic and thermosetting resins.

[0043] Thermoplastic resins are linear or branched polymers, which can be melted by providing them with an appropriate amount of heat; they can be forged (and reforged) into any shape.

[0044] Normally, these polymers have not very high melting temperatures (120-220°C), regretfully easily reachable by the enormous amount of energy that the sliding and dissipation pads made with them must dissipate in the short time interval of a few seconds, typical of a seismic event.

[0045] Thermosetting resins, on the other hand, are materials consisting of cross-linked polymers in which the motion of the polymer chains is strongly limited by the high number of existing cross-links. During the transformation phase, they undergo an irreversible chemical modification, which prevents their remelting and thus raises their thermal resistance, on average, above 250-300°C.

[0046] It follows that their actual usefulness in anti-seismic isolators of the sliding pendulum type, such as the one indicated with 1 in figure 1, never discovered or exploited until now in the field of building and civil engineering for the manufacture of sliding and dissipation pads, such as the one indicated by reference numeral 4 in figure 1, because thermoplastic resins are considered already widely performing for this purpose in terms of the developed friction coefficient.

[0047] Particularly, the laminar layer 5 presents a thickness of a value comprised in the 2-10 mm range.

[0048] More preferably, such a thickness of the laminar layer 5 has a value comprised in the range of 4-6 mm.

[0049] In a preferred but not binding manner, the laminar layer 5 is uniformly distributed, in thickness and surface extension, on both the outer faces 4a, 4b of the sliding and dissipation pad 4.

[0050] In addition, the laminar layer 5 consists in this case of a prefabricated component, such as a sheet or plate of various thickness, applied to both the aforesaid outer faces 4a, 4b of said sliding and dissipation pad 4, made of metal, through any one of the stable connection systems chosen from the group consisting of hooking means, coupling means, fitting means, mechanical interference means, screw means, gluing means and the like.

[0051] Also such a constructive expedient of providing the laminar layer 5 as a prefabricated element, distinct from the sliding and dissipation pad 4, to which it is coupled by means of one of the aforementioned stable connection systems, is an element of significant distinction between the invention claimed herein and the closest prior art, constituted as seen by the prior art documents JP6173639 B1 and CN106223508 B in which such a laminar layer consists of, respectively:

• in JP6173639 B1, a simple adhesive epoxy resin layer, which does not present dissipation function, as it is the case of the corresponding laminar layer 5 coupled to the sliding and dissipation pad 4 of the anti-seismic isolator 1 of the invention, but only the function of coupling the fabric layer to the pad;
• in CN106223508 B, a simple film (or film or veil) made of polytetrafluoroethylene (PTFE) and having a very reduced thickness (values comprised between 0.03 and 0.04 mm) sprayed over an electro-deposited chromium layer applied on the outer surface of the pad; to operate in a more or less effective manner, said film precisely requires the electro-deposited support layer, to the disadvantage of greater constructive complexity of the anti-seismic isolator described herein relative to the anti-seismic isolator 1 of the present invention.

[0052] According to a preferred embodiment of the invention described herein, the thermosetting resin is any one of the plastic materials chosen from the group consisting of phenolic resin (e.g., of density equal to 1.31 g/cm³), amide resin, epoxy resin, polyurethane resin, unsaturated polyester resin, silicone resin, alkyl resin and/or combinations thereof.

[0053] Preferably further, the thermosetting resin is filled with woven fibers incorporated in the cross-linking phase of said thermosetting resin.

[0054] Such braided fibers are made, for example, of any one of the fiber reinforcements chosen from the group consisting of glass fibers, carbon fibers, basalt fibers, aramid fibers and/or combinations thereof; these materials have the advantage of offering light weight and high mechanical strength to the sliding and dissipation pad 4.

[0055] It is understood, however, that other additives may be used to increase or decrease the sliding properties, i.e. to increase or decrease the friction coefficient of the sliding and dissipation pad of the anti-seismic isolator of the invention.

[0056] The inner surface 2a, 3a of the lower plate 2 and the upper plate 3 respectively, in a preferred but appropriate manner, is concave, while the outer faces 4a, 4b of the sliding and dissipation pad 4 has a shape mating with that of the outer surface 2a, 3a of the lower plate 2 and the upper plate 3, which they respectively face, that is convex in this case, as clearly shown in figure 3.

[0057] Preferably, but not necessarily, the inner surface 2a of the lower plate 2 and the inner surface 3a of the upper plate 3 have the same curvature; in this manner, the displacements of the sliding and dissipation pad 4 relative to the equilibrium position will be distributed in equal parts on the two inner sliding surfaces 2a, 3a. In other embodiments of the dissipative anti-seismic isolator of the invention, not shown in the accompanying drawings, the inner surface of the lower plate and the inner surface of the upper plate may have different curvature; in such an embodiment, a different distribution of the displacement of the sliding and dissipation pad on the two inner sliding surfaces is obtained, which is quite useful and desirable in given situations or operating conditions.

[0058] Further embodiments of the dissipative anti-seismic isolator of the invention, not yet shown in the list of accompanying figures, may provide that the inner surface of at least one between the lower plate and the upper plate has a transition arc, such as, in an illustrative and particular manner, a chlotoid, to better center the pad.

[0059] Due to the functional dependence of the radius of curvature on its distance from the center of the dissipative isolator and the local coordinates respectively, the return behavior of the isolator itself (in combination with other parameters, such as friction) can be adjusted; a transition arc, and in particular a chlotoid, generates a particularly advantageous sliding and dissipation pad return behavior.

[0060] Specifically, the inner surface 2a, 3a of the lower plate 2, and said upper plate 3 are made of any one of the low-friction coefficient metallic materials selected from the group consisting of stainless steel, hard chromium coated metallic materials, anodized aluminum, nickel phosphate and/or combinations thereof, in varying proportions.

[0061] Preferably, but not limitingly, at least one (in this specific case, both) the lower plate 2 and the upper plate 3 comprises limit stop means, collectively numbered by reference numeral 6, adapted to delimit the displacement or oscillation of the sliding and dissipation pad 4, according to random lateral directions orthogonal to the linear axis Y first introduced, during the natural phenomenon or human-made event.

[0062] In more detail, the limit stop means 6 include, for example, a raised annular wall 7 which:

• protrudes from the inner surface 2a, 3a, axially facing a respective one of said outer faces 4a, 4b of said sliding and dissipation pad 4, of at least one of the lower plate 2 and said upper plate 3;
• is arranged at the lateral edge 2b, 3b of the lower plate 2 and the upper plate 3, respectively.

[0063] It is understood that, in other embodiments of the dissipative anti-seismic isolator of the present invention, not shown hereinafter, the limit stop means may have a different constructional design from that just described, e.g. a plurality of arched teeth which are aligned with each other, consecutive, spaced, or spaced at the perimeter of the lower plate and/or the upper plate.

[0064] Furthermore, in further embodiments of the dissipative anti-seismic isolator of the present invention, not shown in the accompanying tables, the limit stop means - of whatever shape - may be associated with only one of the two support plates facing each other (and divided by the intermediate sliding and dissipation pad).

[0065] By virtue of the description just given, it is thus understood that the dissipative anti-seismic isolator of the sliding pendulum type for protecting constructions, object of the present invention, achieves the purposes and achieve the advantages already mentioned.

[0066] In addition to those already mentioned above, thermosetting resins offer other advantages in the application object of the present invention, such as high resistance to chemicals, high thermal stability, resistance to deformation under load and plastic deformation, low weight, high electrical insulation properties. Furthermore, compared to thermoplastic resins, thermosetting resins do not decay in the presence of light and have a generally lower cost, which is reflected in a largely competitive cost of the dissipative anti-seismic isolator of the sliding pendulum type of the invention.

[0067] Furthermore, in the invention, the constructive expedient of interposing between the two lower and upper support plates at least one sliding and dissipation pad not made of sliding material of thermoplastic nature, notoriously characterized by elastoplastic behaviors, pronounced creep and high deformations phenomena, allows the anti-seismic isolation device object of the invention not to be affected by wear and loss of anti-seismic performance over time, or at least to be affected to a much lesser extent than the known devices.

[0068] Another salient feature of thermosetting resins is their high dimensional moldability. As indicated above, in anti-seismic applications the sliding and dissipation pad is typically shaped as a spherical cap. Using thermoplastic products, it is necessary to start from flat sheets or plates and carry out either a thermoforming treatment - i.e. a transformation of the semi-finished product into the desired shaped object by means of a mold - in which the sheet must first be heated, usually with infrared lamps and then placed on the mold in which it assumes the desired shape by applying a counter-mold - or by plastically deforming them to allow their insertion between the two spherically processed steel surfaces.

[0069] The first process determines an increase in costs, while the second one causes a loss of mechanical properties having inserted residual stresses given by the plasticization process in the thermoplastic component.

[0070] The use of thermosetting resins, preferably in the form of prefabricated laminar layers, on the other hand, makes it possible to have the spherical (or convex) cap of the sliding pad of the correct shape and size quickly, immediately, in real time, making application easy and guaranteeing the mechanical properties of the product.

[0071] In the execution phase, modifications can be made to the dissipative anti-seismic isolator of the sliding pendulum type of the present invention e.g. consisting in the fact that only one of the two outer faces axially opposite to each other of the sliding and dissipation pad comprises a laminar coating layer (in such case in direct contact with only one of said outer faces and, at the same time and on the opposite side, with the outer surface of the lower plate or of the upper plate) made at least partially of thermosetting resin, either filled or not with interwoven fibers incorporated in the cross-linking phase of the thermosetting resin.

[0072] In addition, in other embodiments of the dissipative anti-seismic isolator of the sliding pendulum type for protecting constructions of the invention, not accompanied by reference figures, only a portion, a part, a surface section of at least one of the two outer faces axially opposite to each other of the sliding and dissipation pad may be coated by means of a laminar layer made of thermosetting resin.

[0073] Furthermore, there may be other embodiments of the invention, not shown in the accompanying drawings, in which the dissipative friction anti-seismic isolator of the mobile pendulum type claimed herein comprises a number of sliding and dissipation pads greater than one, typically two, to constitute an anti-seismic isolator of the double sliding pendulum type, which does not affect the advantage brought by the present invention.

[0074] Finally, it is clear that many other changes could be made to the dissipative friction anti-seismic isolator for protecting constructions of the mobile pendulum type concerned, without departing from the principles of novelty inherent in the inventive idea, just as it is apparent that in the practical implementation of the invention, the materials, shapes, and sizes of the details shown may be any according to the requirements and may be replaced by other technically equivalent elements.

[0075] Where the constructive features and techniques mentioned in any successive claims are followed by references signs or numerals, such reference signs were introduced for the sole purpose of increasing intelligibility of the claims themselves and consequently, such reference signs have no limiting effect on the interpretation of each element identified by way of example only by such reference signs.

Claims

1. Anti-seismic isolator of the sliding pendulum type (1) for protecting constructions, comprising:

- a lower plate (2) adapted to be arranged close to a foundation structure;

- an upper plate (3) arranged above said lower plate (2) along a linear axis (Y) and adapted at least to contribute to supporting an elevated structure to dissipate the kinetic energy transmitted to said elevated structure by a natural phenomenon or by a human-caused event and provided with a high release of total energy;

- at least one sliding and dissipation pad (4) arranged simply resting against said lower plate (2) and said upper plate (3) between which it is interposed to swing freely on an inner surface (2a, 3a) of said lower plate (2) and said upper plate (3) according to one or more random side directions, orthogonal to said linear axis (Y), alternately between an equilibrium position, assumed in absence of said natural phenomenon or said human-caused event, wherein said sliding and dissipation pad (4), said lower plate (2) and said upper plate (3) are substantially coaxial to each other, and a plurality of instability positions, assumed while said natural phenomenon or said human-caused event is in progress, wherein said sliding and dissipation pad (4), said lower plate (2) and said upper plate (3) are offset from each other, to dissipate said kinetic energy of said natural phenomenon or said human-caused event, transmitted to said elevated structure,

characterized in that at least one of said two outer faces (4a, 4b), axially opposite to each other along said linear axis (Y), of said sliding and dissipation pad (4) is at least partially coated with a laminar layer (5), which is made of thermosetting resin and is in direct contact with both at least one of said outer faces (4a, 4b) of said sliding and dissipation pad (4) as well as of said inner surface (2a, 3a) of said lower plate (2) and/or of said upper plate (3).

2. An isolator (1) according to claims 1), characterized in that said laminar layer (5) has a thickness of value comprised in the range from 2 to 10 mm.

3. An isolator (1) according to claim 2), characterized in that said thickness of each of said laminar layer (5) has a value included in the range from 4 to 6 mm.

4. An isolator (1) according to any one of the preceding claims, characterized in that said laminar layer (5) is uniformly distributed, by thickness and surface extension, on at least one of said outer faces (4a, 4b) of said sliding and dissipation pad (4).

5. An isolator (1) according to any one of the preceding claims, characterized in that said laminar layer (5) is a prefabricated component applied to at least one of said outer faces (4a, 4b) of said sliding and dissipation pad (4), made of metallic material, through any one of the connection systems chosen from the group consisting of hooking means, coupling means, fitting means, mechanical interference means, screw means, gluing means and the like.

6. An isolator (1) according to any one of the preceding claims, characterized in that said thermosetting resin is any one of the plastic materials chosen from the group consisting of phenolic resin, amide resin, epoxy resin, polyurethane resin, unsaturated polyester resin, silicone resin, alkyl resin and/or combinations thereof.

7. An isolator (1) according to any one of the preceding claims, characterized in that said thermosetting resin is loaded with braided fibers incorporated in the cross-linking step of said thermosetting resin.

8. An isolator (1) according to claim 7), characterized in that said braided fibers are made in any one of the fiber reinforcements chosen from the group consisting of glass fibers, carbon fibers, basalt fibers, aramid fibers and/or combinations thereof.

9. An isolator (1) according to any one of the preceding claims, characterized in that said inner surface (2a, 3a) of at least one of said lower plate (2) and said upper plate (3) is concave, and at least one of said outer faces (4a, 4b) of said sliding and dissipation pad (4), facing said inner convex surface (2a, 3a) of at least one of either said lower plate (2) and said upper plate (3), is convex.

10. An isolator (1) according to claim 9), characterized in that said inner surface (2a) of said lower plate (2) and said inner surface (3a) of said upper plate (3) have the same curvature.

11. An isolator according to claim 9), characterized in that said inner surface of said lower plate and said inner surface of said upper plate have different curvature.

12. An isolator according to any one of claims 9) to 11), characterized in that said inner surface of at least one of said lower plate and said upper plate has a transition arc.

13. An isolator (1) according to any one of the preceding claims, characterized in that said inner surface (2a, 3a) of at least one of said lower plate (2) and said upper plate (3) is made of any one of the metallic low-friction coefficient materials selected from the group consisting of stainless steel, hard chromium coated metallic materials, anodized aluminum, nickel phosphate and/or combinations thereof.

14. An isolator (1) according to any one of the preceding claims, characterized in that at least one of said lower plate (2) and said upper plate (3) comprises limit stop means adapted to delimit the movement or oscillation of said sliding and dissipation pad (4), according to said random side directions orthogonal to said linear axis (Y), during said natural phenomenon or said human-caused event.

15. An isolator (1) according to claim 14), characterized in that said limit stop means include a raised annular wall (7) which:

• protrudes from said inner surface (2a, 3a), axially facing one of said outer faces (4a, 4b) of said sliding and dissipation pad (4), of at least one of said lower plate (2) and said upper plate (3);

• is arranged at the lateral edge (2b, 3b) of at least one of said lower plate (2) and said upper plate (3).

Drawing