Patent Publication Number: US-2022228426-A1

Title: Vacuum insulated glazing, valve, flexible seal, and method for making vacuum insulated glazing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. 63/138,948 filed on Jan. 19, 2021, entitled “Pulse Strengthened and Laser Edge Fused Sealed Vacuum Insulation Glazing (VIG)”, the entire disclosure of which incorporated herein by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     This invention was made with government support under Contract No. DE-AC05-000R22725 awarded by the U.S. Department of Energy. The government has certain rights in this invention. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to vacuum insulated glazing, and more particularly to methods and systems for making vacuum insulated glazing. 
     BACKGROUND OF THE INVENTION 
     Vacuum insulated glazing (VIG) is a highly thermally insulated window technology that provides superior insulation compared to most current window technologies. Vacuum insulated glazing is generally constructed of a minimum of two glass panes with an enclosed, highly evacuated cavity between the panes which serves as a vacuum space. A high vacuum (below 0.001 torr) allows for near zero heat conduction and convection, making it ideal insulation. Heat transfer through radiation is still a possibility in the vacuum space, however there are many different options for low emittance (low-E) coatings that reduce radiation transmittance between glass. Producing and maintaining a vacuum between two panes of glass presents some design challenges. 
     First of the addressed challenges is supporting the glass while retaining the low-conductivity. As a vacuum is created, atmospheric pressure on the glass will deform it. If the glass deforms significantly, the two panes may touch, producing a conduction path. To prevent this, supports such as pillars and spacers are placed in a regular grid between the two panes of glass, for example every 2″ or less, so up to 0.04″ gap between panes can be supported without contact. There are several options for making these supports. Different options are available for making the support materials between the glass less visible, stronger, and more insulating. 
     Second of the challenges is making an edge seal between the panes of glass that will hold a vacuum for the 20+ year lifespan of VIG. Due to the potential temperature differential between the inside and the outside of the VIG, thermal stress can be developed within the edge seal material resulting in the failure of the edge seal and thus the loss of vacuum. Current technologies for addressing this challenge are flexible edge seal, low thermal-budget laser-assisted hermetic sealing etc., thus eliminating a thermo-compression step which requires high temperature processing. The use of fused glass as an edge seal can create a bond which is able to resist the thermal stress due to having the same thermal expansion properties. In this manner, thermal stress, which is the common cause of edge seal failure in conventional VIG technology, can be reduced. 
     The third of the addressed challenges is providing a vacuum valve built into the VIG to allow the vacuum to be created during some stage of, or after, assembly. In conventional technologies it is done by machining a countersink in one of the glass panes, then using a device to create a vacuum through the hole before pressing an indium sphere into the countersink, sealing it. However, this creates localized stress, a cause of VIG failure, and the valve is exposed within the glazing vision of the window. 
     SUMMARY OF THE INVENTION 
     A vacuum insulated glazing includes first and second spaced apart glass panes having perimeter portions. The glass panes define a vacuum space between the glass panes. A vacuum valve is positioned at the perimeter portions of the glass panes. The vacuum valve includes a valve body. A portion of the valve body extends between the perimeter portions of the glass panes. The valve body has first and second ends and a fluid conduit having corresponding first and second ends and extending from the first end to the second end of the valve body. The first end of the fluid conduit is in fluid communication with the vacuum space. A one-way valve in the valve body is positioned between the first end and the second end of the fluid conduit. The one-way valve permits fluid flow in the fluid conduit from the first end to the second end, and prevents fluid flow from the second end to the first end of the fluid conduit. A suction fitting is provided for connecting the valve body to a suction device in fluid communication with the second end of the fluid conduit. An end seal is provided between the perimeter portions of the glass panes for hermetically sealing the vacuum space. Suction when applied to the suction fitting will draw a gas from the vacuum space through the first end of the fluid conduit, through the one-way valve and the second end of the fluid conduit to create a vacuum in the vacuum space, and the one-way valve will prevent the passage of the gas into the vacuum space so as to maintain the vacuum in the vacuum space. 
     The fluid conduit at the first end can be smaller in cross section than at the second end. The fluid conduit can be conical. The one-way valve can include a movable valve member in fluid conduit. The valve member can have first and second positions in the fluid conduit. The valve member in the first position prevents fluid flow through the conduit, and in the second position permits fluid flow through the conduit. The valve member can be a spherical ball. A restricting member can be provided for preventing movement of the valve member through the second end of the fluid conduit. 
     A sealing member can be provided for attaching to the valve body and hermetically sealing the fluid conduit. The valve body can be rectangular in cross section and can have a height dimensioned to fit between the spaced apart glass panes. The suction fitting can be detachable from valve body. The vacuum insulated glazing can further include spacers extending between the glass panes and through the vacuum space. 
     The end seal can include an end seal member having free ends. The valve body can have channel members for positioning and securing the free ends of the end seal member. The valve body can have depressions for receiving free end portions of the end seal members. 
     A method of making a vacuum insulated glazing can include the step of providing first and second spaced apart glass panes having perimeter portions, the glass panes defining a vacuum space between the glass panes. A vacuum valve is positioned at the perimeter portions of the glass panes, the vacuum valve comprising a valve body, a portion of the valve body extending between the perimeter portions of the glass panes. The valve body has first and second ends and a fluid conduit having corresponding first and second ends and extending from the first end to the second end of the valve body. The first end of the fluid conduit is in fluid communication with the vacuum space. A one-way valve in the valve body is positioned between the first end and the second end of the fluid conduit. The one-way valve permits fluid flow in the fluid conduit from the first end to the second end, and prevents fluid flow from the second end to the first end of the fluid conduit. A suction fitting provided at or attached to the second end of the valve body is used to connect the valve body to a suction device in fluid communication with the second end of the fluid conduit. 
     An end seal metallic barrier is positioned and attached between the perimeter portions of the glass panes to hermetically seal the vacuum space. A suction source is connected to the suction fitting and suction is applied to withdraw a gas from the vacuum space through the fluid conduit to create a vacuum in the vacuum conduit. The suction is stopped and the suction source is removed from the suction fitting, whereby the one-way valve will prevent the flow of air through the vacuum conduit into the vacuum space. 
     The method can further include the step of attaching a sealing member to the valve body to hermetically seal the fluid conduit. The method can further include the step of removing a portion of the valve body extending beyond the perimeter portion of the glass panes prior to attaching the sealing member. 
     A vacuum valve for vacuum insulated glazing has first and second spaced apart glass panes with perimeter portions, the glass panes defining a vacuum space between the glass panes. The vacuum valve includes a valve body, a portion of the valve body dimensioned to extend between the perimeter portions of the glass panes. The valve body has first and second ends and a fluid conduit has corresponding first and second ends extending from the first end to the second end of the valve body. The first end of the fluid conduit can be used for establishing a fluid communication with the vacuum space. A one-way valve in the valve body is positioned between the first end and the second end of the fluid conduit. The one-way valve permits fluid flow in the fluid conduit from the first end to the second end, and prevents fluid flow from the second end to the first end of the fluid conduit. A suction fitting is provided for attaching the second end of the valve body to a suction source in fluid communication with the second end of the fluid conduit. Suction when applied to the suction fitting will draw a gas from the vacuum space through the first end of the fluid conduit and through the one-way valve to the second end of the fluid conduit and through the suction passage, and the one-way valve will prevent the passage of the gas into the vacuum space so as to maintain a vacuum in in the vacuum space. 
     The fluid conduit at the first end can be smaller in cross section than at the second end. The fluid conduit can be conical. The one-way valve can include a movable valve member in fluid conduit. The valve member has first and second positions in the fluid conduit. The valve member in the first position prevents fluid flow through the conduit, and in the second position permits fluid flow through the conduit. The valve member can be a spherical ball. A restricting member can be provided for preventing movement of the valve member through the second end of the fluid conduit. 
     A sealing member can attach to the valve body and hermetically sealing the fluid conduit. The sealing member can be a sealing cap for sealing the second end of the fluid conduit. The suction fitting can be detachable from the valve body and can include a suction passage for establishing a fluid connection with the second end of the fluid conduit. Vacuum insulated glazing can include first and second spaced apart glass panes having perimeter portions and defining a vacuum space between the glass panes, and the valve body can be dimensioned to fit between the perimeter portions of the glass panes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       There are shown in the drawings embodiments that are presently preferred it being understood that the invention is not limited to the arrangements and instrumentalities shown, wherein: 
         FIG. 1  is a perspective view of VIG, in a first stage of assembly. 
         FIG. 2  is a perspective view of VIG, in a second stage of assembly. 
         FIG. 3  is an exploded perspective view of VIG, in a third stage of assembly. 
         FIG. 4  is a side elevation of a spherical ball valve member. 
         FIG. 5  is a perspective view of a restricting member. 
         FIG. 6  is a perspective view of VIG, in a fourth stage of assembly. 
         FIG. 7  is a perspective view of VIG, in a fifth stage of assembly. 
         FIG. 8  is a perspective view of VIG, in a sixth stage of assembly. 
         FIG. 9  is a perspective view of VIG, in a seventh stage of assembly. 
         FIG. 10  is a perspective view of VIG, in an eighth stage of assembly. 
         FIG. 11  is a perspective view of VIG, in a ninth stage of assembly. 
         FIG. 12  is an expanded perspective view of area  12  in  FIG. 11 . 
         FIG. 13  is an exploded perspective view of area  13  in  FIG. 11 , depicting a subsequent stage of assembly. 
         FIG. 14  is a cross section of a VIG and a vacuum valve assembly. 
         FIG. 14A  is an expanded view of area  14 A in  FIG. 14 . 
         FIG. 14B  is an expanded view of area  14 B in  FIG. 14 . 
         FIG. 15  is a cross section of a vacuum valve. 
         FIG. 15A  is an expanded view of area  15 A in  FIG. 15 . 
         FIG. 16  is an exploded perspective view of VIG and a vacuum valve. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A vacuum insulated glazing according to the present invention includes first and second spaced apart glass panes having perimeter portions. A vacuum space is between the glass panes. A vacuum valve is positioned at the perimeter portions of the glass panes. The vacuum valve includes a valve body. A portion of the valve body extends between the perimeter portions of the glass panes. The valve body has first and second ends. A fluid conduit has corresponding first and second ends and extends from the first end to the second end of the valve body. The first end of the fluid conduit is in fluid communication with the vacuum space. A one-way valve in the valve body is positioned between the first end and the second end of the fluid conduit. The one-way valve permits fluid flow in the fluid conduit from the first end to the second end, and prevents fluid flow from the second end to the first end of the fluid conduit. A suction fitting is provided for connecting the valve body to a suction device in fluid communication with the second end of the fluid conduit. An end seal between the perimeter portions of the glass panes is provided for hermetically sealing the vacuum space. Suction applied to the suction fitting will draw a gas from the vacuum space through the first end of the fluid conduit, through the one-way valve and the second end of the fluid conduit to create a vacuum in the vacuum space, and the one-way valve will prevent the passage of a gas such as air into the vacuum space so as to maintain the vacuum in the vacuum space. 
     The one-way valve can have many different constructions, such as biased flap valve members, rotating valve members, spring biased valve members, and other constructions. In one embodiment, the one-way valve has a movable valve member in the fluid conduit. The valve member has first and second positions in the fluid conduit, the valve member in the first position preventing fluid flow through the conduit, and in the second position permitting fluid flow through the conduit. The valve member can be a spherical ball. The fluid conduit can be shaped such that the ball or other valve member has a valve seat against which the valve member rests to close the conduit and prevent fluid flow from the second end to the first end of the conduit. The valve member is moved off of the valve seat by a reduction in pressure at the second end, as by the application of suction. A restricting member prevents movement of the valve member through the second end of the fluid conduit. The restricting member can be an obstruction such as a post, a protrusion or a screen which blocks escape by the spherical ball valve member while permitting gas to flow past the restriction. Other constructions for the one-way valve are possible. 
     The fluid conduit can have differing shapes, sizes and geometries. The fluid conduit can be circular in cross section or rectangular. In one embodiment, the fluid conduit at the first end is smaller in cross section than at the second end. The fluid conduit can be essentially a tapering, slightly conical shape such that a valve member in the shape of a spherical ball will seat against a portion of the cone having the same diameter to close the conduit against flow from the second end to the first end, and can move away from the valve seat when suction is applied. 
     The one-way valve will prevent the movement of gas (air) from the second end to the first end of the fluid conduit and thereby from the surroundings into the vacuum space, so as to preserve the vacuum within the vacuum space. The VIG must however maintain the vacuum for many years, preferably decades. It is therefore desirable to provide a secondary seal for the fluid conduit after the suction has been disconnected, which will additionally seal the fluid conduit. A sealing member can be provided for attaching to the valve body and hermetically sealing the fluid conduit. The sealing member can take varies forms. The sealing member can be a weld, plug or adhesive material that permanently fills and blocks the fluid conduit. The sealing member can be a cap which is attached over the valve body and secures and seals the fluid conduit. The cap can be secured by any suitable method including but not limited to welds, adhesives, threaded connections, and others. 
     The valve body can have different sizes, shapes and geometries. The portion of the valve body that extends between the perimeter portions of the glass panes will preferably be shaped and sized to closely fit this space, although various seats, mounts and bushings are possible to seal the space between the valve body and the glass panes. The valve body can be rectangular in cross section and have a height dimensioned to fit between the spaced apart glass panes. As the spacing between the glass panes can be quite small, such as 0.04″ or less, the valve body can have at least a portion which is dimensioned to fit in this gap between the perimeter portions. 
     A suction device is attached to the valve body to withdraw gas through the fluid conduit and form the vacuum in the vacuum space. The valve body can be provided with a suction fitting for this purpose. The suction fitting can be any suitable structure that is sized and shaped to mate with a corresponding suction device attached to a suction source such as a vacuum pump. The suction fitting portion can be detachable and can be a threaded fitting, a snap fitting, or a seat for a suction hose that is secured with a hose clamp of some kind. In one embodiment, the suction fitting is barbed for attaching to a flexible hose that is pushed over the barbs, as is common in fluid handling systems. The suction fitting portion of the valve body can be detachable from the rest of the valve body after use, such that the suction fitting will not protrude and interfere with the installation of the VIG in a window or door frame assembly. 
     The vacuum insulated glazing can be made of any suitable window glass material including mixtures of materials. It is desirable to provide supports between the glass panes to prevent the glass contact/collapse due to the stress that would otherwise be placed on the glass panes by the difference in pressure between the vacuum space and the ambient air. Supports made of metal or ceramic material can extend between the glass panes and through the vacuum space to provide this support. 
     The invention can be used with different end seals. End seals of differing constructions and materials are known in the VIG art. The end seal members proposed in this invention can be made of polymeric materials and/or metals or combination of both that can form hermetic and durable seals, and are preferably metallic materials with low heat conductivity such as titanium and alloys thereof. The end seal members are attached and sealed to the glass panes by known methods and materials such as adhesives. Any suitable such end seal construction and material can be used. It is necessary that the end seal material is sealed against the valve body to ensure that the connection is hermetic and does not permit the entry of air into the vacuum space or result in outgassing. This can be accomplished by the provision of suitable metal structure, such as wire, which does not allow outgassing or diffusion of gas into the vacuum space, for securing the end seal to the vacuum body. This structure can form a barrier, such as a metal wire, along the perimeter of the vacuum space. Adhesive can be placed to adhere the wire. The vacuum body can also be provided with channel members for receiving, positioning and securing the free ends of the end seal members. 
     A method of making a vacuum insulated glazing can include the steps of providing first and second spaced apart glass panes having perimeter portions, the glass panes defining a vacuum space between the glass panes. A vacuum valve is positioned at the perimeter portions of the glass panes. The vacuum valve includes a valve body. A portion of the valve body extends between the perimeter portions of the glass panes. The valve body has first and second ends and a fluid conduit having corresponding first and second ends which extend from the first end to the second end of the valve body. The first end of the fluid conduit is in fluid communication with the vacuum space. A one-way valve in the valve body is positioned between the first end and the second end of the fluid conduit. The one-way valve permits fluid flow in the fluid conduit from the first end to the second end, and prevents fluid flow from the second end to the first end of the fluid conduit. A suction fitting is provided at the second end of the valve body for connecting the valve body to a suction device in fluid communication with the second end of the fluid conduit. An end seal is positioned and attached between the perimeter portions of the glass panes to hermetically seal the vacuum space. A suction source is connected to the suction fitting. Suction is applied to withdraw a gas from the vacuum space through the fluid conduit to create a vacuum in the vacuum conduit. The suction is stopped, and the suction source is removed from the suction fitting, whereby the one-way valve will prevent the flow of air through the vacuum conduit into the vacuum space. 
     The method can further include the step of attaching a sealing member to the valve body to hermetically seal the fluid conduit. This can be accomplished by suitable adhesives or methods such as welding. The method can include the step of removing a portion of the valve body extending beyond the perimeter portion of the glass panes prior to attaching the sealing member. 
     Suction devices of different kinds and constructions can be used with the method of the invention. The device can be pumps of different sizes, styles and constructions, and are known in the VIG art. 
     The valve can be made by different methods including injection molding and additive manufacturing methods. Additive manufacturing methods are useful because of the very small size of the valve body. The spherical ball valve member can be positioned in the fluid conduit and thereafter the restricting member can be positioned to prevent the spherical ball valve member from escaping the fluid conduit. 
     There is shown in  FIGS. 1-16  a vacuum insulated glazing  10  and a system and method for making the same. As shown in  FIG. 1 , a first windowpane  20  has side edges  22 ,  24 ,  26  and  28 . As shown in  FIG. 2 , a bead of adhesive material  34  can be placed around perimeter portions of the windowpane  20 . As shown in  FIG. 3 , a vacuum valve  40  having first end portion  46  and opposite second end portion is provided with a valve body  44 . The valve body  44  can have a restriction seat portion  48  for a restricting member  64 . A suction fitting portion  52  at the second end of the valve body  44  permits attachment to a suction source (not shown). The vacuum valve can have different constructions, and can be a ball valve utilizing a spherical ball valve member  60 , as shown in  FIG. 4 . The restricting member  64  can take various shapes, and as shown in  FIG. 5  can be cylindrical and have a slot  68  or other structure to provide for an elastic and secure attachment in an appropriate seat such as the opening  70  ( FIG. 16 ). The suction fitting portion  52  at the second end portion of the vacuum valve  40  can have suitable structures such as threaded opening  56  for attaching to a suitable suction/vacuum source. 
     As shown in  FIG. 6 , an edge seal in the form of a metallic barrier material  74  is placed around the perimeter portions of the windowpane  20  adjacent the adhesive material  34 . The metallic barrier material  74  also create a barrier between the adhesive material  34  and the vacuum space. The vacuum space should not be exposed to adhesive material  34 . The metallic barrier material  74  can be pre-shaped for this purpose. As shown in  FIG. 7 , a second windowpane  80  can be provided and has side edges  82 ,  84 ,  86  and  88 . The bead of adhesive material  94  (shown through the windowpane  80 ) can be applied to underside perimeter portions of the windowpane  80  so as to engage with the edge seal material  74 , as shown in  FIG. 8 . The bead  94  is sometimes not necessary as the adhesive material  34  can in some instances be sufficient in amount to properly adhere the windowpane  20 , metallic barrier  74  and windowpane  80 . 
     The vacuum space between the windowpane  20 , the windowpane  80  and the metallic barrier end material  74  is then evacuated to create a vacuum. As shown in  FIG. 9 , air particles  100  fill the vacuum space. A barbed fitting  98  can be secured to or form the suction fitting portion  52  for purposes of attaching a suction hose  104 , which can be of indefinite length as shown by phantom break  106  ( FIG. 10 ). A fluid conduit  130  can extend from a first end portion in communication with the vacuum space to an opposite second end portion of the valve body  44 . Air  100  is withdrawn through the fluid conduit  130  from the vacuum space as indicated by arrow  105 , leaving reduced air  100  in the vacuum space and creating an insulating vacuum in the vacuum space between the glass panes  20  and  80 . 
     After the vacuum has been formed in the vacuum space, the suction hose  104  is removed. A portion of the valve body  44  may protrude from the perimeter portions of the glass panes  20  and  80 , such as side edges  28  and  86 . Such protruding portions can be removed to facilitate the installation of the vacuum insulated glazing into a window frame. As shown in  FIG. 11 , after removal an end portion  116  of the valve body  44  extends a little or not at all past the side edges  28  and  86 . The removal of the valve body  44  can performed by suitable structure such as a robotic saw or laser which cuts the valve body  44  at the end portion  116 . A frangible portion such as a break line  110  or groove can be provided to permit snapping and removing the protruding portion of the valve body  44 , as shown in  FIGS. 12-13 . Alternatively, the valve body  44  can be formed with detachable connections such that the protruding portion of the valve body  44  can be detached from the end portion  116  by disengaging the detachable connections. Sealing structure such as an endcap, plug or weld  118  can be used to seal the end portion to prevent the intrusion of air into the vacuum space through the end portion  116 . 
     As shown in  FIG. 14 , the valve body can have an internal valve passage  130  and the plug or weld  118  can be used to seal the internal valve passage or fluid conduit  130  at the end portion  116 . The suction fitting  52  and the barb portion  98  can have an in internal passage  99  which communicates with the internal valve passage  130  to permit the withdrawal of air from the vacuum space. The barb portion  98  can be secured to the suction fitting portion  52  by detachable structures such as male threads  134  and female threads  136 . Other attachment structure is possible. 
     As shown in  FIG. 14A , the restricting member  64  when placed in the opening  70  is positioned in front of an end portion of the internal vacuum passage  130 . The restricting member  64  extends through an internal opening  53  formed by walls  55  of the restriction seat portion  48 . The restricting member  64  and the restriction seat portion  48  are dimensioned as shown in  FIG. 14A  such that upon the application of suction air will be withdrawn through the internal valve passage or fluid conduit  130  and the internal opening  53  and will flow around the restricting member  64  as shown by arrows  150 . The dimensions are selected so as to permit the passage of air past the restricting member  64 , but to prevent the passage of the spherical valve member ball  60 , which is drawn by the suction to the end of the fluid conduit  130 . 
     The metallic barrier end seal material  74  is placed so as to create a continuous metallic barrier to retain vacuum. This step would ensure that the metal barrier  74  is created all around the perimeter space, preventing the outgassing or diffusion. This metallic barrier end seal material must be held in an appropriate position as the adhesive layers  34  and  94  cure and set. The valve body  44  can be provided with structure to secure free ends  76  of the metallic barrier end seal material. As shown in  FIG. 14B  and  FIGS. 15-15A , protruding channel members  140 ,  141 ,  142  and  143  can be provided to position and secure the free ends  76  of the metallic barrier end seal material  74 . The free ends  76  of the metallic barrier end seal material  74  can be tapered into points. The pointed free ends  76  can be received by depressions  78  formed in the valve body  44  to further secure the free ends of the metallic barrier end seal material  74  in position. 
     The fluid conduit  130  can have a tapering internal diameter, such as with a larger diameter at a position  132  and a smaller diameter at a position  131  adjacent the vacuum space  133  between the glass panes  20  and  80 . When suction is removed, the spherical valve member ball  60  will be drawn by the vacuum of the vacuum space  133  as shown by arrows  136  to a position  138  where the diameter of the internal valve passage  130  matches the diameter of the spherical valve member ball  60  such that the spherical valve member ball  60  will close and seal the internal valve passage  130 . The vacuum in the vacuum space can be quite high, below 0.001 torr. Supports such as pillars or spacers  135  can be provided between the glass panes, for example every 2″, to keep the glass panes separated and free of distorting bends. 
     The invention as shown in the drawings and described in detail herein disclose arrangements of elements of particular construction and configuration for illustrating preferred embodiments of structure and method of operation of the present invention. It is to be understood however, that elements of different construction and configuration and other arrangements thereof, other than those illustrated and described may be employed in accordance with the spirit of the invention, and such changes, alternations and modifications as would occur to those skilled in the art are considered to be within the scope of this invention as broadly defined in the appended claims. In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.