SECURITY WINDOW This invention relates generally to an exterior window which is designed to prevent unauthorized entry into a home or business. Such a security window is often less attractive than a window that would have been selected for architectural harmony and/or other decorative reasons. Additionally or alternatively, an attractive window is often made from breakable glass sometimes creating safety issues in geographical areas prone to high powered storms such as hurricanes.
The present invention provides a security window which can be designed to be attractive, secure, and storm-resistant. More particularly, the present invention provides a panel assembly for mounting in a frame to form such a security window.
The panel assembly of the present invention comprises two outer panels positioned in a face-to-face relationship and made of a light-transmitting material (e. g., glass), and an inner panel positioned between the two-outer panels and made of a light- transmitting material having a greater impact resistance than the two outer panels (e. g., window glass laminated with polycarbonate resin or a single layer of polycarbonate material). The two outer panels can each have a film of plastic material (e. g., a polyester film) applied to at least one of their surfaces thereby making the panels have enhanced thermal performance, increased impact strength, improved shatter resistance, and better sun protection. Additionally or alternatively, the chambers between the panels can contain Aragon gas thereby providing increased thermal and acoustical values.
A cross-section of a security window 10 incorporating a panel assembly 12 according to the present invention is shown in the Drawing. In addition to the panel assembly 12, the security window 10 comprises a frame 14 which can be made of wood, aluminum or any other suitable frame material for exterior windows. The panel assembly 12 comprises panels 16,18 and 20 which are positioned in spaced relation so that a chamber 22 is defined between the outer panel 16 and the inner panel 18 and a chamber 24 is defined by between the inner panel 18 and the panel 20. In the illustrated embodiment, this spacing is accomplished by spacers 26 and 28.
The outer panels 16 and 20 can be made of any type of suitable window glass, such as annealed, tinted, tempered, low-E, reflective or obscure glass. The outer panels can be made of the same or different materials and the panels'thickness can vary depending on application. In any event, the inwardly facing surfaces of the panels 16 and 20 are coated with a polyester film 30 of a suitable thickness (e. g. 2 mil., 4 mil., 7 mil., 18 mil. and/or 20 mil.). In the illustrated embodiment, the protective film 30 is heated and pressed onto each of the glass panels 16 and 20.
The inner panel 18 is light-transmissible and has an impact resistance greater than the outer panels 16 and 20. To this end, the inner panel 18 can be made of window glass laminated with polycarbonate resin or may be single layer of polycarbonate material. The panel's thickness should be sufficient (e. g., 1/8"or greater) for the circumstances such as, for example, being impact-resistant (and/or bullet-proofl in high-crime areas and/or capable of withstanding applicable impact and cycling tests (e. g., Dade County Impact and Cycling Test NOA #98-0515. 03) in storm- susceptible areas.
The spacers 26 and 28 are made of material providing sufficient structural strength. For example, the spacers 26 and 28 may be made of architectural class silicon foam products containing a desiccant and adhered in position by suitable adhesive. The advantage of such foam products is that the spacers 26 and 28 will further reduce heat transmission and reduce condensation in the event of temperature changes. This may be especially significant if the inner layer 18 has a laminate structure to reduce the delaminating problems often associated with, for example, polycarbonate reenforced glass. Alternatively, the spacers 26 and 28 may be made of aluminum or metal.
In the illustrated embodiment, the panel assembly 12 additionally comprises an edge sealant 32 around the panel and spacer perimeters. The sealant 32 can be a warm-applied elastomeric insulating glass sealant such as a one component 100% solids sealant system specifically developed for edge sealing insulated glass units.
The sealant 32 keeps moisture from entering the chambers 22 and 24, provides additional structural strength, and/or provides an expandable material for the inner panel 18 to expand if the assembly is exposed to environmental extremes of heat and cold in use.
According to one embodiment of the present invention, Argon gas fills the chambers 22 and 24. The sealant 30 prevents moisture vapor transmission into the chambers 22 and 24 and also prevents the Argon from leaking therefrom.
Alternatively, the chambers 22 and 24 can be evacuated during assembly of the window 10.
Thus, in the security window 10 according to the present invention, the frame 14 and the outer panels 16 and 20 can be selected for architectural harmony, decorative, or other atheistically pleasing reasons since the inner layer 18 provides the necessary structural integrity for security and/or impact-protection purposes. The polyester film 30 on the panels 16 and 20 provides improved thermal performance and increased impact strength. In fact, the security window 10 of the present invention can be designed to pass all applicable Hurricane tests while still providing the desired atheistic and necessary security.
The polyester film 30 also provides shatter protection in that, if the glass panel 16 and/or 20 is broken, the glass shards will adhere to the film rather than being introduced to the surrounding environment. Furthermore, the polyester film 30 serves as a sun shield for the inner panel 18 in that it can block out virtually 100% of UV rays.
This sun-blocking component for the inner panel 18 is important when the inner panel 18 is made of polycarbonate which tends to fade and yellow over time from sun exposure. Additionally or alternatively, the filling of the chambers 22 and 24 with Argon gas improves the window's thermal and acoustical performance.
In a method of manufacturing the security window 10 according to the present invention, the outer panels 16 and 20 are cut to the designated size and the inner panel 18 is also cut to its designated size. If the outer panels 16 and 20 are made of glass and the inner panel 18 is made polycarbonate, the inner panel 18 will be cut smaller in both height and width than the outer panels 16 and 20. A small 1/8"hole is drilled into the inner panel 18 to equalize pressure in the chambers 22 and 24.
The outer panel 16 is run through a glass washer into a Hepa-controlled clean room where it is passed through a lamination machine. In the lamination machine, the polyester film 30 is heated, pressed and sealed to the glass panel 16. The glass panel 16 (with polyester film 30 thereon) is removed from the clean room and placed on a table where the spacer 26 is applied.
Thereafter, the glass panel 16 (with polyester film 30 and spacer 26 thereon) is placed on a vertical assembly table. Small lifts (sized to accommodate the dimensions of the inner layer 18) are then placed on the assembly table against panel 16 both vertically and horizontally. The inner polycarbonate layer 18 is placed on the lifts and pressed against the spacer 26 on the panel 16.
The outer glass panel 20 is then washed, laminated with the polyester film 30, and has the spacer 28 applied thereto in same manner as explained above in connection with outer glass panel 16. The outer panel 20 is then placed on the assembly table so that the spacer 28 faces the inner polycarbonate panel 18 and pressed thereagainst.
Argon gas is then pumped into the chambers 22 and 24 and, once the chambers 22 and 24 are filled, the unit is run through a cold press to seal it together and retain the Argon in the chambers 22 and 24. The perimeter of the unit is then filled with the sealant 32.
