Abstract:
Two parallel glass panes are separated by a core spacer made of either EPDM rubber or another solid rubber material with a nonheating, centrally positioned, nonstretchable fiberglass cord being embedded therein and extending longitudinally therethrough so that the core spacer is not stretchable. The EPDM rubber formulation is chemically compatible with hot melt butyl which is used as an adhesive between the solid rubber and the glass panes. The fiberglass cord is nonstretchable so that the core spacer does not deform or break apart when the core spacer is either initially manufactured or later placed between the pair of two glass panes. The core spacer and the cord extend around a periphery and go around corners between the panes in an airtight manner to form an insulated assembly. Also, the cord has a diameter no greater than about 10% of a width of the core spacer. A method for manufacturing the insulated assembly is likewise disclosed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 09/421,504, filed on Oct. 20, 1999, which claims priority from U.S. Provisional Patent Application Ser. No. 60/115,953 filed on Jan. 14, 1999. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to an insulated glass assembly and, in particular, to core spacers separating glass panes.  
           [0004]    2. Description of the Related Art  
           [0005]    Insulating glass is usually made of at least two panes adhered together along their edges by a core spacer. In the prior art, there are several types of core spacers manufactured from synthetic foam which is soft and easily compressed. Exemplary is the spacer shown in U.S. Pat. No. 5,806,272 which was issued to Lafond on Sept. 15, 1998.  
           [0006]    However, such foam core spacers have minimal stability because of their easy compressibility. Furthermore, such foam spacers are readily stretched longitudinally, thus allowing them to be deformed or broken apart before, during or after installation in a window frame.  
           [0007]    Another disadvantage of foam core spacers is that they often interact chemically with hot melt butyl, thus causing a stain discoloration which is unacceptable aesthetically. Such a chemical reaction further frequently causes a variety of other problems, like a change in adhesion strength, a shrinkage of the foam spacer, or an expansion thereof. Whenever a shrinkage occurs, the spacer tends to pull away from the corners where the glass panes are joined together. Likewise, if an expansion occurs, the foam spacer becomes misshapen and appears unattractive.  
         SUMMARY OF THE INVENTION  
         [0008]    A solid EPDM rubber core spacer is provided with a centrally positioned, nonstretchable cord made of fiberglass or similar material for imparting strength thereto. Furthermore, the EPDM rubber formulation is chemically compatible with hot melt butyl which is used as an adhesive and as a moisture vapor barrier. Although there are many differences between the hot melt butyls manufactured by different companies, it is important to formulate an EPDM rubber which ensures chemical compatibility.  
           [0009]    A key advantage of the present invention is improved stability over foam core spacers when in compression during oven pressing, packing, shipping, and installing in windows. In each situation, the solid rubber core spacer undergoes significantly less compression than the foam of the prior art spacers.  
           [0010]    Another advantage of the present invention is the incorporation of the fiberglass cord into the rubber core spacer so that no stretching of the spacer occurs during initial manufacture, spacer assembly, coiling of the spacer, and application of the finished spacer between two glass panes. Also, heating and cooling of the spacer does not result in any deformation or breakage of the spacer when in use because of the presence of the continuous nonstretchable fiberglass cord incorporated therein. Of course, in the real world, everything can be stretched to a breaking point if a powerful enough pulling force is exerted. In that sense, the fiberglass cord is nonstretchable under normal conditions of use.  
           [0011]    A further advantage of the present invention is that the chemical composition of the EPDM rubber in the core spacer is such that it does not react, other than in a minimally inconsequential way, with hot melt butyl. Thus, this feature of the present invention prevents a chemical reaction that could cause a stain discoloration, a change of adhesion strength, shrinkage, expansion or any other disadvantage inherent in the prior art foam core spacers whenever a chemical reaction takes place.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a perspective view of a first embodiment of the present invention.  
         [0013]    [0013]FIG. 2 is a side elevational view of the first embodiment.  
         [0014]    [0014]FIG. 3 is an exploded side elevational view of a second embodiment.  
         [0015]    [0015]FIG. 4 a  is a side elevational view of a third embodiment.  
         [0016]    [0016]FIG. 4 b  is a side elevational view of a fourth embodiment.  
         [0017]    [0017]FIG. 4 c  is a side elevational view of a fifth embodiment.  
         [0018]    [0018]FIG. 4 d  is a side elevational view of a sixth embodiment.  
         [0019]    [0019]FIG. 4 e  is a side elevational view of a seventh embodiment.  
         [0020]    [0020]FIG. 4 f  is a side elevational view of an eighth embodiment.  
         [0021]    [0021]FIG. 4 g  is a side elevational view of a ninth embodiment.  
         [0022]    [0022]FIG. 4 h  is a side elevational view of a tenth embodiment.  
         [0023]    [0023]FIG. 4 i  is a side elevational view of an eleventh embodiment.  
         [0024]    [0024]FIG. 5 is an exploded side elevational view of a twelfth embodiment.  
         [0025]    [0025]FIG. 6 is a perspective view of the first embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    In FIG. 1, a first embodiment of a rubber core spacer  10 , noncircular in shape, is shown with a top side  12 , a bottom side  14 , a short side  16 , a long side  18 , and two diagonally cut corners  20  and  22 . A single, nonheating, nonstretchable, centrally positioned fiberglass cord  24  is embedded in the rubber core spacer  10  when the latter is manufactured so that the core spacer  10  is not stretchable. The preferred rubber formulation for the spacer  10  is an ethylene propylene diene monomer (EPDM) polymer with fillers. However, other solid rubber materials may be suitable.  
         [0027]    The height H varies according to the width selected for the spacer  10 . Thus, the height H may range from as little as one quarter to three quarters of an inch or greater.  
         [0028]    The cord  24  is cylindrical in shape and has a diameter of at least 0.01 inch which is sufficient for the cord  24  to be effective inside the spacer  10 . However, the preferred diameter is 0.02 inch. In FIG. 1, it can be seen that the cord  24  has its diameter no greater than about 10% of the width of the spacer  10 .  
         [0029]    In FIG. 2, a first hot butyl melt adhesive  26  is applied around at least two sides, but preferably the three sides  12 ,  14 ,  16  and the corners  20  and  22  of the core spacer  10 , although it is sufficient to be applied around only the top side  12  and the bottom side  14 . This first adhesive  26  sticks the core spacer  10  between a pair composed of a top glass pane  32  and a bottom glass pane  34 . These glass panes  32  and  34  are flat sheets that are parallel to each other. After the first adhesive  26  is positioned, a desiccant  38  is arranged adjacent to the core spacer  10  and is spaced between the pair of parallel panes  32  and  34  by a second hot butyl melt adhesive  28  which is applied around at least two sides and preferably three sides of the desiccant  38  to hold the desiccant  38  between the pair of parallel panes  32  and  34 . This desiccant  38  is a drying agent intended to absorb any moisture between the panes  32  and  34  and is open on one side  40  to the space separating the panes  32  and  34 . Desiccants are well known in the prior art and many types may be suitable.  
         [0030]    In FIG. 3, a second embodiment is shown in an exploded view in which the desiccant  38  has cut corners  46  and  48  to help the second adhesive  28  hold a vapor barrier  30  in place between the core spacer  10  and the desiccant  38 . The vapor barrier  30  may be a metallized plastic film embedded at both ends in the second adhesive  28 . The core spacer  10  remains in the same position, surrounded on all sides, except for the long side  18 , by the first adhesive  26 . The two panes  32  and  34 , as in the first embodiment seen in FIGS. 1 and 2, are held apart by the core spacer  10  while the desiccant  38  absorbs any moisture in the space therebetween.  
         [0031]    In FIG. 4 a,  a third embodiment is shown in which the spacer  10  has its corners  20   a  and  22   a  cut longer than the corners  20  and  22  seen in the first embodiment of FIGS. 1 and 2.  
         [0032]    In FIG. 4 b,  a fourth embodiment is shown in which corners  20   b  and  22   b  of the spacer  10  come to a point  16   b  instead of to the side  16 , as seen in the first embodiment of FIGS.  1 - 2 .  
         [0033]    [0033]FIGS. 4 c  through  4   g  show further embodiments in which patterns are cut into the top side  12  and the bottom side  14  of the spacer  10  to form voids for a purpose to be described.  
         [0034]    In FIG. 4 c,  a fifth embodiment is shown in which the spacer  10  has triangular indentations  12   c  and  14   c  in the top side  12  and the bottom side  14 , respectively.  
         [0035]    In FIG. 4 d,  a sixth embodiment is shown in which the spacer  10  has a plurality of serrated teeth  12   d  and  14   d  in the top side  12  and the bottom side  14 , respectively.  
         [0036]    In FIG. 4 e,  a seventh embodiment is shown in which the spacer  10  has scalloped recesses  12   e  and  14   e  in the top side  12  and the bottom side  14 , respectively.  
         [0037]    In FIG. 4 f,  an eighth embodiment is shown in which the spacer  10  has deep grooves  12   f  and  14   f  in the top side  12  and the bottom side  14 , respectively.  
         [0038]    In FIG. 4 g,  a ninth embodiment is shown in which the spacer  10  has a plurality of shallow channels  12   g  and  14   g  in the top side  12  and the bottom side  14 , respectively.  
         [0039]    In FIG. 4 h,  a tenth embodiment is shown in which the spacer  10  has wide depressions  12   h  and  14   h  in the top side  12  and the bottom side  14 , respectively. However, unlike the embodiments shown in FIGS. 4 a  through  4   g,  the spacer  10  in FIG. 4 h  does not have any cut diagonal corners.  
         [0040]    The purpose of the indentations  12   c  and  14   c  in FIG. 4 c,  the teeth  12   d  and  14   d  in FIG. 4 d,  the recesses  12   e  and  14   e  in FIG. 4 e,  the grooves  12   f  and  14   f  in FIG. 4 f,  the channels  12   g  and  14   g  in FIG. 4 g,  and the depressions  12   h  and  14   h  in FIG. 4 h,  is to allow the first adhesive  26  illustrated in FIGS.  1 - 3  to fill the voids therein so that the adhesive  26  sticks better to the spacer  10  and to the glass panes  32  and  34  of FIGS.  1 - 3 .  
         [0041]    In FIG. 4 i,  an eleventh embodiment is shown in which the spacer  10  has a rectangular cross section through which the cord  24  is centrally positioned. Note that there are no diagonally cut corners and no indentations.  
         [0042]    In FIG. 5, a twelfth embodiment is shown in which a third hot melt butyl adhesive  50  is applied between the first adhesive  26  and the vapor barrier  30  to orient the vapor barrier  30  at both ends perpendicular to the pair of parallel glass panes  32  and  34 . The amount of the second adhesive  28  used is less than the amount used in the second embodiment of FIG. 3. The third adhesive  50  may be uncured silicone or urethane.  
         [0043]    Also, instead of the diagonally cut corners  46  and  48  of FIG. 3, the twelfth embodiment in FIG. 5 has smaller square cut corners  46   a  and  48   a  so that the desiccant  38  is left with a top surface  54  and a bottom surface  56  which provide additional frictional engagement with the top glass pane  32  and the bottom glass pane  34 , respectively. In this twelfth embodiment, the six-sided spacer  10  is the same size as the spacer  10 , shown in the first and second embodiments of FIGS.  1 - 3 , with the top surface  54 , the bottom surface  56 , two other sides, and at least two cut corners  46   a  and  48   a.  In other words, the top surface  54  and the bottom surface  56  of the core spacer  10  have a pattern cut therein, as seen in FIG. 5, to form voids which receive the second adhesive  28 . This pattern may be described as a plurality of shallow channels.  
         [0044]    When heat is applied to cure the third adhesive  50 , the entire assembly of FIG. 5 has more structural integrity because the cured third adhesive  50  attaches itself firmly to the second adhesive  26 , the metallized vapor barrier  30 , and both glass panes  32  and  34 .  
         [0045]    In FIG. 6, the first embodiment of FIGS. 1 and 2 is shown in place, without the second adhesive  28  and the desiccant  38 , for ease of illustration. The spacer  10  is adhered at its top side  12  to the top glass pane  32  and also is adhered at its bottom side  14  to the bottom glass pane  34 . The glass panes  32  and  34  are parallel to each other but are separated by an interior space  52  to form an entire insulated glass assembly. The spacer  10  and the core  24  extend around the entire periphery and go around corners between the panes  32  and  34  in an airtight manner to form the entire insulated glass assembly. At a 90° corner  42 , either the spacer  10  is flexed, thus causing some curvature in the corner  42 , or the spacer  10  is cut, thus allowing a sharp 90° corner  42  to be formed. In the latter case, an exterior corner void is back-filled with the adhesive  26 , as shown in the embodiments of FIGS. 2, 3 and  5 . Note that it is necessary to cut only the spacer  10  and not any other materials, such as the second adhesive  28  and the desiccant  38  in FIG. 2 or the same two materials and the vapor barrier  30  in FIG. 3, or the three last listed materials and the adhesive  50  in FIG. 5. Consequently, the nonstretchable fiberglass cord  24  running therethrough allows the rubber spacer  10  to maintain its structural integrity by preventing the rubber spacer  10  from stretching. Thus, the entire insulated glass assembly is kept intact so that no moisture enters the interior space  52  between the panes  32  and  34 .  
         [0046]    The present invention also encompasses a method for manufacturing the insulated assembly having the interior space. The method includes an initial step of providing the pair of parallel glass panes  32  and  34  separated by the interior space. The method also includes the further steps of embedding the nonheating, nonstretchable cord  24  in a central position of the rubber core spacer so that the rubber core spacer  10  is not stretchable; applying the first adhesive  26  around at least two sides of the core spacer  10  for sticking the core spacer  10  between the pair of parallel glass panes  32  and  34 ; arranging the desiccant  38  adjacent to the core spacer  10  and spacing the desiccant  38  between the pair of parallel glass panes  32  and  34 ; applying the second adhesive  28  around at least two sides of the desiccant  38  to hold the desiccant  38  between the pair of parallel glass panes  32  and  34 ; holding the vapor barrier  30  in place between the core spacer  10  and the desiccant  38 ; and applying the third adhesive  50  between the first adhesive  26  and the vapor barrier  30  to orient the vapor barrier  30  at both ends perpendicular to the pair of parallel glass panes  32  and  34 . The last step is extending the core spacer  10  and the cord  24  around the periphery and around the corners between the pair of parallel glass panes  32  and  34  in an airtight manner to form the insulated assembly. In the completed assembly, as best shown in FIGS. 3 and 6, the cord  24  has a diameter no greater than about 10% of the width of the core spacer  10 .  
         [0047]    The above-described embodiments are not limiting, but can be modified in various ways within the scope and spirit of the present invention.