Patent Publication Number: US-8534019-B2

Title: Glass block with low-e center lite

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Stage Patent Application filed under 35 U.S.C. §371 claiming priority to PCT/US2009/004250 having an international filing date of Jul. 22, 2009. This application claims the benefit of US Provisional Patent Application 61/082,724 filed Jul. 22, 2008. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The application generally relates to multiple glazing sheet glazing units and, more particularly, to glass blocks. Specifically, the application relates to a glass block having an internal center lite that may be a low-e center lite and/or an internal insulating glazing unit incorporating clear and/or low-e glazing. 
     2. Background Information 
     Glass blocks have been used for years in numerous applications. Traditional glass blocks are available in various sizes and thicknesses. All of these sizes and thicknesses have front and rear glass lites spaced apart by a glass sidewall. Glass blocks are formed by heating two block halves to a temperature hot enough to weld or fuse the block halves together when the sidewalls are abutted against one another. 
     Recent energy conservation requirements encourage the use of a low emissivity coating (low-e coating) on window units to reduce radiant heat transfer. Glass block manufacturers thus desire to add a low-e coating to at least one of the glass block halves or to add an internal low-e coated lite to the interior of the glass block. The step of fusing the glass block halves together will destroy a low-e coating added to a glass block half prior to the fusing step. 
     SUMMARY OF THE INVENTION 
     The invention generally provides a glass block having an internal low-e coated lite. The internal chamber of the glass block is sealed against moisture vapor. 
     Another configuration of the invention provides a spacer for a glass block that separates the glass block halves and supports a center lite. The center lite may be low-e coated. The internal chamber of the glass block may be sealed to prevent moisture vapor from migrating into the glass block. 
     Another configuration of the invention provides a method for sealing the sidewall of the glass block after the interior lite is assembled between the glass block halves. 
     Another configuration of the invention provides a glass block having an interior low-e coated lite wherein the internal chamber of the glass block is sealed against moisture vapor migration. The glass block halves are separated by a thermal break. The sidewall of the glass block is configured to have a uniform appearance when viewed through the front or rear lites of the glass block. 
     Another configuration of the invention provides a glass block having an interior insulating glazing unit sealed within the glass block assembly wherein the entire glass block/insulating glazing unit are sealed against moisture vapor migration. Additionally, said unit configurations are sealed against insulating gas egress (e.g., argon, krypton, etc.) from the glass block system. 
     A further configuration of the invention generally provides a glass block spacer adapted to hold a pair of interior lites. 
     In one configuration, the invention provides a glass block assembly having first and second glass block halves; each glass block half having a sidewall and an outer face; the sidewalls having inner surfaces and outer surfaces; the glass block halves facing each other to define an internal chamber; a spacer disposed between the glass block halves to thermally isolate the first glass block half from the second glass block half; the spacer including a body disposed directly between the sidewalls of the glass block halves; a sealant disposed between the spacer and the glass block to hermetically seal the internal chamber; the spacer having a pair of legs extending laterally outwardly from the body to define shoulders that engage the inner surfaces of the first and second glass block halves; the legs of the spacer defining a slot; and an interior lite disposed in the interior chamber; the interior lite being carried in the slot. 
     Another configuration of the invention provides a glass block assembly having first and second glass block halves; each glass block half having a sidewall and an outer face; the sidewalls having inner surfaces and outer surfaces; the glass block halves facing each other to define an internal chamber; a spacer disposed between the glass block halves to thermally isolate the first glass block half from the second glass block half; the spacer including a body disposed directly between the sidewalls of the glass block halves; a sealant disposed between the spacer and the glass block to hermetically seal the internal chamber; the spacer having a pair of legs extending laterally outwardly from the body to define shoulders that engage the inner surfaces of the first and second glass block halves; each of the legs of the spacer having an outer surface; and a first interior lite disposed in the interior chamber; the first interior lite being adhesively connected to the outer surface of one leg. 
     The invention also provides a method of forming a glass block having a low-e interior lite wherein the method includes the steps of wrapping the outer perimeter of a low-e interior lite with a spacer; positioning the spacer on a first glass block half; connecting a second glass block half to the spacer to sandwich the spacer between the glass block halves and to position the low-e interior lite in an internal chamber; and applying a sealant to the spacer and the glass block halves to hermetically seal the internal chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a section view of the top half of a glass block showing a spacer holding a single interior lite. 
         FIG. 2  is a view similar to  FIG. 1  showing an extrusion die that may be used to add a layer of sealant to the outer surface of the sidewall over the top of the spacer. 
         FIG. 3  is a view similar to  FIG. 1  showing a pair of interior lites supported by the spacer. 
         FIG. 4  is an enlarged view of an exemplary spacer. 
         FIG. 5  is a view similar to.  FIG. 1  showing the use of a sealant tape to seal the spacer. 
         FIG. 6  is a section view taken through a glass block with a center lite held by a spacer. 
     
    
    
     Similar numbers refer to similar parts throughout the application. 
     DETAILED DESCRIPTION OF THE INVENTION 
     An exemplary glass block having at least one interior lite is indicated generally by the numeral  2  in the accompanying drawings. Glass block  2  includes first  4  and second  6  glass block halves, a spacer  8 , and an interior lite  10 . Interior lite  10  may be coated with a low-e coating. Interior lite  10  may be glass. Glass block  2  also includes a seal that hermetically seals the inner chamber of glass block  2 . 
     Each glass block half  4  and  6  includes a sidewall  12  disposed substantially perpendicular to the outer face  14  of half  4  and  6 . 
     Two exemplary configurations of spacer  8  are depicted.  FIGS. 1-3  depict a first configuration and  FIG. 4  depicts a second configuration. Each spacer  8  may be fabricated from a silicone material or any of a variety of other flexible spacer materials known in the art. For example, spacer  8  may be a silicone, a rubber, an EPDM, or a plastic. The material may be foamed. Spacer  8  carries a desiccant to adsorb moisture in the chamber of glass block  2  to prevent condensation or fogging inside glass block  2 . Spacer  8  may be 50 percent (by weight) desiccant. 
     Each spacer configuration includes a body  20  disposed directly between the ends of sidewalls  12  and either or both of a head  22  disposed outwardly of the sidewalls  12  and at least one leg  24  extending into the internal chamber of glass block  2 . In the exemplary configuration, spacer  8  includes two spaced legs  24  that define a slot  25  that receives the outer circumferential edge of lite  10 . Each spacer configuration optionally may be provided with a pair of arms  26  that extend parallel to the inner surface of sidewalls  12 . The first configuration of spacer  8  positions slot  25  inwardly of the inner surfaces of sidewalls  12  such that no portion of slot  25  is disposed directly between the ends of sidewalls  12 . The end of slot  25  may be spaced inwardly from the inner surfaces of sidewall  12  a distance greater than the thickness of lite  10 . The second configuration of spacer  8  extends slot  25  directly between the ends of sidewalls  12 . 
     In the first configuration of spacer  8 , lite  10  may be secured with an optional adhesive  30  disposed in slot  25 . In the second configuration of spacer  8 , optional fingers  32  extend into slot  25  to frictionally hold lite  10 . Fingers  32  are angled toward the end of slot  25  to provide a holding force to lite  10 . Adhesive  30  and fingers  32  may be used together or alone in both of the configurations of spacer  8 . Adhesive  30  and fingers  32  may be removed. 
     In both of the exemplary configurations, legs  24  define a shoulder  40  that rests against the inner surface of sidewalls  12 . Shoulders  40  position spacer  8  with respect to sidewalls  12  during the assembly of unit  2 . In another configuration, legs  24  are the same width as body  20 . 
     When arms  26  are used, each arm  26  projects away from legs  24  along the inner surface of sidewall  12 . Each arm  26  is not as tall as legs  24  so that a corner is defined that may be used to seat the outer circumferential edge of lite  10  as shown in  FIG. 3 . Adhesive  30  may be used hold lite  10  against the outer surface of leg  24  or against the inwardly-facing surface of arms  26 . When lite  10  is used on the outside of leg  24 , adhesive  30  disposed in slot  25  is not necessary. This configuration may be used to form an assembly  2  having one, two, or three lites  10 . 
     Head  22  is optional. In the configurations having head  22 , head  22  is wider than body  20  so that portions of head  22  extend over the outer surfaces of sidewalls  12  to define notches. These notches may receive and hold sealant. Body  20  may protrude outwardly beyond the outer surface of sidewalls  12  to position head  22  spaced outwardly from the outer surfaces of sidewalls  12 . 
     Spacer  8  may be held between glass block halves  4  and  6  with an adhesive  50  such as an acrylic adhesive. A pressure sensitive acrylic adhesive  50  may be used. In situations where moisture vapor sealing properties are desired, a sealant  50 , such as polyisobutylene (PIB), may be disposed between body  20  and the ends of sidewalls  12 . Adhesive  50  may provide a dual function by providing the adhesive strength and the sealing properties. 
     In some optional configurations, a moisture vapor barrier, such as a metal foil, may be wrapped around head  22  and body  24  to prevent moisture vapor from penetrating spacer  8  from outside of glass block  2 . 
     Glass block  2  also may be sealed by (1) placing a bead of sealant into the notches defined between head  22 , body  20 , and sidewalls  12 . This is useful when a moisture vapor barrier foil is used. Glass block  2  also may be sealed by (2) covering the exposed portions of spacer  8  with a sealant—such as a PIB, a hot melt butyl, or a reactive hot melt sealant—as shown, for example, in  FIG. 3  by reference numeral  60 . Sealant  60  covers the seams where halves  4  and  6  engage spacer  8 . A drawback with this method is that bead  60  is visible through the inner surface of sidewalls  12  when viewed along sight lines  62  (see  FIG. 3  for reference). Bead  60  forms an undesirable incongruity to the appearance of sidewall  12 . In order to eliminate this incongruity, sealant bead  60  may be stretched to cover the entire outer surface of sidewalls  12 —from lip  70  to lip  70 —as shown in  FIG. 2 . Such a bead  60  may be extruded with a wide die  72 . Another manner of sealing spacer  8  is (3) to wrap spacer  8  with an adhesive tape  80  that sticks to glass and is impervious to moisture vapor. Tape  80  may include an inner sealant layer  82  (such as a PIB or a butyl) with an outer body layer (that may be waterproof). A waterproof outer body layer may be necessary when a water-based mortar will be used to connect adjacent glass blocks  2 . Tape  80  may be as wide as lips  70  to provide a uniform appearance to glass block  2 . Another method of providing a uniform appearance is to seal spacer  8  with a sealant bead  60  and then paint the outer surface of sidewalls  12  with a paint that matches the color of sealant bead  60 . 
     Glass block  2  may be assembled by first wrapping spacer  8  around the outer perimeter of liter  10  wherein spacer  8  is held in place by adhesive  30  disposed in slot  25 , by fingers  32 , or by friction. The wrapped lite is then connected to one of the glass block halves  4  or  6  by adhesively connecting one side of body  20  to the end of wall  12 . The adhesive may be carried by the outer surface of body  20 . The corner defined between one leg  24  and body  20  helps align spacer  8  in the correct position all the way around glass block half  4  or  6  when the wrapped lite is initially positioned. The other glass block half  4  or  6  is then pressed down onto the other side of spacer body  20  and adhesively secured. The unit is then hermetically sealed by one of the methods described above such as by extruding a sealant over the exposed outer surface of spacer  8 . 
     In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described. Throughout the description and claims of this specification the word “comprise” and variations of that word, such as “comprises” and “comprising,” are not intended to exclude additives, components, integers, or steps.