MXPA99005981A - Safety glass structure resistant to extreme wind and impact - Google Patents

Abstract

A safety glass structure (20) which is resistant to extreme wind- and impact-conditions. In particular, the safety glass structure (20) comprises a frame forming an opening and defining an outer rigid channel (1);a laminated glass panel (10) within the opening comprising first and second glass layers (5, 6) bonded to an interlayer of plasticized polyvinyl butyral (7);an inner rigid channel (8) within the frame circumscribing the periphery of and bonded to said laminated glass panel (10) by a self-sealing adhesive (9) which permits no or minimal relative movement between the border area of the panel (10) and said inner rigid channel (8);and said inner rigid channel (8) being mounted in and bonded to the outer rigid channel (1) with a resilient material (11) which permits the panel (10) to flex within its border when exposed to said extreme wind- and impact-conditions. The safety glass structure of the present invention may be used in residential or commercial structures to preserve the integrity of the building in extreme weather conditions.

Description

SAFETY GLASS STRUCTURE RESISTANT TO EXTREME WIND AND IMPACT BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates to a laminated safety glass structure useful in commercial or residential constructions and which resists extreme wind conditions and impact. In particular, the safety glass structure consists of a conventional laminated safety glass panel (ie two glass layers adhered to an intermediate polyvinyl butyral sheet) whose perimeter is mounted in a frame of rigid structure in such a way that the edges of the glass panel are held rigidly in the frame, and the overall structure is sufficiently rigid and robust to withstand impacts or extreme winds. As a result, the integrity of the safety glass is preserved, even in extreme weather conditions such as hurricanes.

RELATED BACKGROUND TECHNIQUE Extreme weather conditions due to hurricanes, tornadoes and the like are capable of causing immense damage to building structures and particularly to windows formed of fragile glass. A hurricane is a large atmospheric whirlpool that can produce sustained winds of 193 kilometers per hour or more (120 miles per hour or more). As a hurricane crosses a coastline and passes into a construction, the construction experiences turbulent, sustained winds that slowly change direction. The sustained winds of a hurricane can last for hours, while its extreme gusts hit the construction periodically. As the direction of the wind changes slowly, the wind finds the least robust member of a structure and in the procedure, causes faults and generates large amounts of waste that is blown by the wind. The severe and complex nature of the hurricane winds cause special problems for buildings. The winds around the roof on the outside of the building tend to push the roof outward. In addition, if the construction envelope is cracked through a window opening failure, the wind enters the building and tends to push the roof and walls outward. Therefore, the forces acting to lift the roof of the building outward are effectively bent when the building envelope has been cracked. The conservation of the integrity of the window openings is also made difficult due to the presence of waste sent by the wind. Attempts have been made to protect glass in the windows by using windows or by designing the glass to remain in the opening after breaking. However, windows or broken glass must withstand sustained gusts of wind that change direction, resulting in changes in pressures that act inward to those that act outward (suction) as the hurricane passes. As a result of these pressure changes, the failure of the window integrity openings is a common occurrence during hurricane conditions. Prior art structures to date have not been designed to functionally withstand extreme hurricane-type weather conditions. The Patent of E.U.A. No. 2,631, 340 describes a storm window construction that fits over a window opening to be sealed. The Patent of E.U.A. No. 5,355,651 discloses a mounting arrangement for securing a window glass panel in a frame consisting of a flexible strip in the form of a channel having openings at spaced intervals along its length. The Patent of E.U.A. No. 4,364,209 discloses window cover strips that snap into place in a window frame and extend around the periphery of a glass panel. The strips that hold firmly hold the glass panel in place and allow the glass panel to be easily removed for repair or replacement. The use of window screens to protect window openings in buildings is well known, but window treatments add additional expense to building construction and require attention to be closed in time before the hurricane arrives. In addition, counter windows are not normally viable in large commercial constructions. For example, the Patent of E.U.A. No. 5,347,775 describes a window against hurricane window during inclement weather. Since Hurricane Andrew devastated South Florida in August 1992, engineers, architects, building officials and others in the construction industry have begun to take the hurricane into consideration as a special design situation. The sustained and turbulent nature of the hurricane winds present new and important challenges to the design of safety glass structures resistant to extreme wind and impact of windborne debris that have not been previously considered in the prior art.

BRIEF DESCRIPTION OF THE INVENTION Improvements have now been made to window structures that contain safety glass that improves performance when exposed to extreme weather conditions such as hurricanes and the like. Accordingly, a principal object of this invention is to provide a safety glass window structure capable of functionally resisting extreme weather conditions resulting from hurricanes, tornadoes and the like. This and other objects are achieved by providing a safety glass structure for residential and commercial buildings that is resistant to extreme wind conditions and impact consisting of: (a) a frame that forms an opening and defines a rigid outer channel; (b) a laminated glass panel within the opening comprising a first and second glass layers bonded to an interlayer of plasticized butyral polyvinyl; (c) a rigid inner channel within the frame circumscribing the periphery of and adhering to the laminated glass panel by means of a self-sealing adhesive which does not allow minimal movement or movement in relation to the edge area of the panel and the inner rigid channel; and (d) the inner rigid channel being mounted on and adhered to the outer rigid channel with a flexible material that allows the panel to deflect within its limit when exposed to the aforementioned extreme wind and impact conditions.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a cross-sectional view of a security glass mode ra of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawing, the safety glass structure 20 consists of a rigid frame structure which, in cross section, is in the form of an outer U-shaped channel 1, the side pieces of which 2 and 3 and the lower part 4 they define an opening into which a glass panel can be inserted. The particular shape of the channel is not critical and can vary as desired to accommodate various installations. The edge of the perimeter of a safety glass panel 10 is mounted in an internal rigid channel 8 and adhered thereto with a self-sealing adhesive 9 which allows minimal or no movement in relation to the safety glass 10 and the interior of the inner rigid channel 8. The laminated safety glass panel 10 consists of first and second glass layers 5 and 6, which may be the same or different, adhered to and encapsulating an intermediate layer 7 of plasticized polyvinyl butyral (PVB). As shown, the inner rigid channel 8 (with its safety glass inserted) is spaced from the inside of the outer rigid channel 1 and adhered thereto with a flexible material 11 which allows flexing movement relative to the exterior of the inner rigid channel 8. and the interior of the outer rigid channel 1. Any flexing of the safety glass structure caused by strong winds or impact of debris carried away by the wind is absorbed by the flexing of the inner channel 8 supporting the glass against the flexible material 11 that separates it. the interior and exterior channels.

If desired, in order to allow water or other elements to run and not accumulate in or near the region where the glass panel 10 is inserted into the interior and exterior channels 8 and 1, the safety glass structure of the present invention may optionally include any suitable material installed in the region such as to form an angle from the face of the glass to the upper part of the side piece of the U-shaped channel. Any conventional material may be used, such as packaging, silicones, tapes and the like. The laminated safety glass panel can be any conventional laminated safety glass typically used in automotive windshields or building structures, which generally consist of two sheets of glass adhered to a polyvinyl butyrallastic interlayer. Interlayers of polyvinyl butyral are well known in the art and those interlayers and methods for their preparation are described in US Patents. No. Re. 20,430, and E.U.A. Nos. 2,496,480 and 3,271, 235. Preferably, the laminated polyvinyl butyralle sheet is 2.29 to 1.52 mm thick (90 to 60 mils). Such films are commercially available from Monsanto Company, St. Louis, MO under the trademark Saflex® sheet and from DuPont Company, Wilmington DE how sheet Butacitel The inner rigid channel enclosing the periphery of the laminated safety glass panel consists of a material rigid having a cross section that is C-, J-, or U-shaped. The edges of the inner rigid channel may be cut angled or square. Preferably, the inner rigid channel must not be overlapped at any point. The width of the inner rigid channel, the thickness of the wall, and the height of the wall defining the channel can be varied as desired. The need to adjust the size and shape of the outer rigid channel to fit an aperture of particular size and a particular size and shape of the inner rigid channel will be apparent to those skilled in the art. The laminated glass panel should be inserted at a sufficient distance inside the rigid inner channel so that almost 1.27 cm(0.5 inch) of the periphery of each glass face is encompassed within the channel, measured from the edge of the panel. The inner rigid channel may be formed of any suitable material, such as aluminum, steel, polyvinyl chloride, nylon or other strong plastic. In the case of aluminum, straight aluminum cuts can be bent into any desired shape and size. For example, two aluminum semicircles may be adhered to cover the circumference of a piece of safety glass. The peripheral edge of the laminated safety glass panel is attached to the inner rigid channel with a self-sealing adhesive. Preferably, the self-sealing adhesive must be flexible, have good adhesion to the glass and channel material, and cure with curing. The preferred self-sealing adhesives are silicones, epoxies, polyurethanes, polyvinyl butyral, polysulfides, butyl sealants and / or gaskets and interlayer material of excess PVB at the edges of the laminated safety glass panel. Other self-sealing adhesives known to those skilled in the art can also be used. In the case of extruded PVB sheet, when the laminate is being constructed, the PVB interlayer sheet is usually larger than the glass sheet, when this excess PVB is present at the edges of the resulting laminate it will function as a self-sealing adhesive If the panel laminated with the excess PVB is inserted inside the rigid inner channel. Generally, the laminate with the channel is self-nailing together by laminating the channel to the glass with excess PVB. Alternatively, the excess PVB at the edges of the laminate can be trimmed with the edges of the glass and used to fill the inner channel before self-nailing to adhere the laminated safety glass panel to the channel. The safety glass mounted in the interior channel is then, in turn, mounted in an exterior channel in a construction frame in a configuration that meets the measurements accepted by the industry of wind load and structural requirements. Although the safety glass structure of the present invention can be used in any type of construction opening in any way, it is typically used in building openings such as windows, doors, and skylights. The rigid outer channel of the structural frame consists of a rigid material having a cross section that is C-shaped, U-shaped, J-shaped, or a combination thereof. The width of the outer rigid channel, the thickness of the wall, and the height of the wall can be varied as required to accommodate the inner rigid channel and the need to vary the parameters of the inner rigid channel to fit an aperture of particular size will be obvious to those skilled in the art. The outer rigid channel can be formed of any suitable material, such as aluminum, polyvinyl chloride "PVC", wood, or any combination or compound thereof (for example, vinyl-coated wooden windows). The inner rigid channel may be adhered to the outer rigid channel with any suitable flexible material, such as an adhesive, which has been caulked within the outer rigid channel. Examples of suitable adhesives include mastic, silicone spheres, epoxies, polyurethanes, polysulfides, butyl materials, packings that fit, adhesive tape in general, or any combination thereof. The glass used in the safety glass structure must meet the standard specifications of the test methods and American "ASTM" standards for flat glass (ASTM C-1036-90) and the standard specification for laminated architectural flat glass (ASTM C- 1172-91). The thickness of glass depends on the wind load requirements for a particular structure. The wind load and glass thickness requirements are determined by standard practice to determine the annealed glass test thickness (ASTM E-1300) and the specified load test (American).

Standards for Civil Engineering "ASCE" - 7-88). Illustrative examples include heat hardened glass, annealed glass, fully tempered glass, and chemically tempered glass. The first and second glass layers used in the safety glass sheets are each preferably 0.24 to 1.27 cm thick (3/32 a VT inch). Window designs that can survive the impact of large projectiles without penetration are important because this type of debris is very common around the lower portion (for example, below 9.1 meters (30 feet)) of a construction during weather conditions. extreme wind caused by hurricanes. It is also common that at 9.1 meters (30 feet) and above is the roof gravel and other small debris from adjacent roofs. If the windows are broken by the impact of these projectiles, the envelope of the building is compromised, unless all the broken glass remains in the opening during the rest of the storm. However, the cyclical pressure developed by the hurricane may result in additional structural damage to the construction. As will be further described hereinafter, the structures of the present invention survive these conditions. Normal tests have been developed to calculate the qualification of products that can be used in wall coverings in hurricane prone regions. These test measures apply to wall coverings, wall panels, windows, doors, skylights, windows, and covers of other openings in building sheaths. Typical for the normal measurements used in the coastal areas is the measure Southern Building Code Congress International, Ine, (Birmingham, Alabama ("SBCCI") to determine the impact resistance of debris thrown by the wind In a typical test, a product is hit by a large projectile or a small projectile at a high speed, depending on the location of the product On the rise of the construction After the impact, the product is subjected to cyclical pressures that represent the sustained turbulent winds of a hurricane, and the direction of the winds is changed as to alter the direction of the application of pressure of action inwards outward action (suction) to mimic typical hurricane conditions This invention will be better understood from the following examples, however, one skilled in the art will readily appreciate that the specific methods and results discussed are only illustrative of the invention and does not imply limitation of the invention, each of the safety glass structures in the following Several examples were subjected to a large projectile impact test and a cyclic pressure load test. The following is a summary of the two test methods used to test the safety glass structures.

IMPACT PROJECTS OF LARGE PROJECTILE Two identical test specimens for each of the safety glass structures were tested with a large projectile. The large projectile consisted of a piece of wood having nominal dimensions of 5.08 centimeters by x 10.16 centimeters (2 inches x 4 inches) with a weight of 4.08 kilograms (9 pounds). The large projectile was propelled into the glass by means of a projectile cannon using compressed air and impacted the surface of each test specimen at a speed of 15.24 m / sec (50 ft / sec). Each test specimen received two impacts: the first within a circle of 12.7 centimeters radius (5 inches) having its center over the midpoint of the test specimen and the second within a circle of 12.7 centimeters radius (5 inches) in a corner that has its center in a location 15.24 centimeters (6 inches) away from any support member. If the test specimens for each safety glass structure successfully pass the projectile impact test (ie, without projectile penetration or without cracking greater than 12.7 centimeters (5 inches)) they completely penetrate through the glass structure of the projectile. safety), then undergo the following cyclic pressure load test.

CYCLIC PRESSURE LOAD TEST In the cyclic pressure load test, two test specimens that successfully survived the large projectile impact test were subjected to a pressure cycle that acts inward (positive pressures) in ascending order followed by a pressure cycle that acts outward. (negative pressures) in descending order as listed in table 1. These pressure cycle loads were applied through a mechanical system adhered to the test specimen in order to apply uniform pressure around the perimeter of the structure. Each cycle lasted three seconds.

CYCLIC WIND PRESSURE CHARGE Note that Pmax denotes the maximum design load in accordance with ASCE 7-88.

The result of the test is a passed / failed criterion. If the two test specimens for each structure reject the two projectile impacts without penetration and resist the cyclic pressure load without cracks formed larger than 12.7 centimeters and 0.16 centimeters wide (1/16 inches) through which the air It may happen, the particular structure was considered to have passed the test.

EXAMPLE 1 The entire periphery of a Isminated glass panel consisting of a 0.23 centimeter (0.090 inch) interlayer marking Saflex® PVB between two 0.32 centimeter (1/8 inch) nominal glass pieces, was bonded into an aluminum tire in forms of C having a wall thickness of 0.16 centimeters (1/16 inch) with a bed of 0.16 centimeters to 0.32 centimeters (1/16 to 1/8 inches) of neutral cure silicone that has been caulked within the tiredness. The resultant laminated glass mounted on the screen was then placed in a neutral test frame cabslet. The neutral test frame stand consists of 0.64 centimeters (1/4 inch) angles with dimensional poles up to 2.54 centimeters x 2.54 centimeters (1 inch x 1 inch). The angles were secured to pine frames of 5.08 centimeters x 15.24 centimeters (2 inches x 6 inches) at intervals of 15.24 centimeters (6 inches) with screws number 10, 3.17 centimeters (1 V *. Inches). The width of the angle depends on the total thickness of the enclosed glass structure and the necessary coating components. The probsds samples were fi xed within a neutral test mark with an additional nominal 0.32 cm (1/8 inch) silicon cure bed on the inner side of the glass panel with a double-sided adhesive foam overlay tape. to the outer side of the glass panel. This configuration passed the impact and cyclic loads of 342 kilograms per meter (70 pounds per foot) "psf".

EXAMPLE 2 The construction of the glass glass structure was the same as in Example 1 except that a C-shaped aluminum channel with a wall thickness of 1/32 inch was adhered to the edge of the laminated glass. This configuration passed the impact and the cyclical loads to 390 kilos per square meter (80 psf).

EXAMPLE 3 The construction of the seguridsd glass structure was the same as in Example 1 except that the laminated glass consisted of a 0.48 centimeter (3/16 inch) piece of nominal heat-strengthened glass bonded on one side of a Ssflex intercaps. ® PVB of 0.23 centimeters (0.090 in.) And a piez of 0.32 centimeters (1/8 in.) Of nominsl annealed glass sdherido on the other side of the PVB. This configuration passed the impact and cyclic load to 390 kilos per square meter (80 psf).

EXAMPLE 4 The construction of the safety glass structure was the same as in Example 1 except that the laminated glass consisted of a 0.48 centimeter (3/16 inch) piece of nominal heat-strengthened glass bonded to one side of an interlayer. Saflex® PVB of 0.23 centimeters (0.090 inches) and a piez of 0.48 centimeters (3/16 inch) of nominal annealed glass bonded on the other side of the PVB. This configuration passed the impact and cyclic load to 390 kilos per square meter (80 psf).

EXAMPLE 5 The construction of the safety glass structure was the same as in Example 1 except that the laminated glass consisted of an interlayer of Saflex® PVB of 0.23 centimeters (0.090 inches) between two pieces of nominal annealed glass of 0.32 centimeters (1 / 8 inches). Isminated glass was adhered directly into the outer channel of the structure without the use of an inner channel. This configuration passed the impact test but failed the cycle csrgs test 293 kilos per meter meter (60 psf).

During the testing of this safety glass structure, a phenomenon known as glass edge release was observed (the glass edge release occurs when the glass is no longer adhered to the glass.

PVB). The small glass particles resulting from the impact test were removed from the PVB during the cyclic loading test and resulted in a structure failure.

EXAMPLE 6 The construction of the safety glass structure was the same as in Example 1 except that a full tempered nominal glass of 0.64 cm (1/4 inch) was used instead of laminated glass. This configuration failed the impact test and therefore the cyclic load test could not be performed.

EXAMPLE 7 The construction of the safety glass structure was the same as in Example 1 except that a nominal tempered full glass of 0.64 cm (1/4 inch) was adhered directly into the channel of the ventsns without the use of an internal tiredness. This configuration resulted in the impetus and therefore cyclic csrgs tests could not be reslized.

The above performance data under simulated extreme wind and impact conditions typically encountered in a severe hurricane dramatically illustrate the advantages of the safety glass structure described. In particular, the safety glass structure of the present invention facilitates bending of the inner channel with the safety glass within the outer channel and thus retains the integrity of a building opening.

In addition, the safety glass structure is easily installed in structural frames of new or older buildings that are exposed to inclement weather conditions.

Claims (12)

NOVELTY OF THE INVENTION CLAIMS

1. - A safety glass structure resistant to extreme and impetus wind conditions, consisting of: (a) A machine that forms a gap and defines a rigid outer shell; (b) A laminated glass panel within the opening comprising first and second glass layers adhered to an interlayer of polyvinyl butyral plasticised. (c) A rigid internal csnsl within the mrc that circumscribes the periphery of and sdherido 3l laminated glass pane by a self-sealing adhesive that does not allow any minimal movement or movement in relation between the edge area of the panel and the inner rigid channel; and (d) The inner rigid channel being mounted on and adhered to the outer rigid channel with a flexible material that allows the panel to flex within its edge when exposed to extreme wind and impact conditions.

2. The safety glass structure according to claim 1, further characterized in that the internal rigid tire has unstructured cross sections selected from the group consisting of C-, J-, and U- shapes.

3. The safety glass structure of conformity with claim 2, further characterized in that the inner rigid channel is made of material selected from the group consisting of aluminum, steel and polyvinyl chloride nylon.

4. The safety glass structure according to claim 1, characterized in that the outer rigid csnsl has uns forms in the trsnsverssl section selected from the group consisting of a C- or U shape.

5.- The glass structure of Safety in accordance with claim 4, further characterizes because the exterior rigid tire is made of material selected from the group consisting of aluminum, polyvinyl chloride, wood, or any combination thereof.

6. The security glass structure according to claim 1, further characterized in that the self-sealing adhesive is selected from the group consisting of silicones, epoxies, polyurethanes, polyvinyl butyral, polysulfides, sealants and butyl gaskets.

7.- The glass structure of conformityd glass with Is claim 1, also characterized in that the flexible material is an adhesive.

8. The security glass structure according to claim 7, further characterized in that the adhesive is selected from mastic, silicone, epoxy, polyurethane, polysulphides, butyl materials, packaging that is fitted, or any combination thereof.

9. - The safety glass structure according to claim 1, further characterized in that the first and second glass layers are the same or different.

10. The safety glass structure according to claim 9, further characterized in that the first and second glass layers are selected from the group consisting of glass reinforced to the crystal, annealed glass, fully tempered glass, and chemically tempered glass.

11. The safety glass structure according to claim 10, further characterized in that the thickness of the first and second glass segments are csds of 0.24 to 1.27 cm (3/32 to? An inch) in thickness.

12. The safety glass structure according to claim 1, further characterized in that the laminated polyvinyl butyralle sheet is 2.29 to 1.52 mm (90 to 60 mils) thick.