Abstract:
A device for simultaneously edge sealing and gas filling an insulated glass unit, the insulated glass unit including a supporting structure that supports the insulated glass unit in a working position and a gas filling module including a gas fill injection structure and a displaced air extraction structure and a gas metering unit. The device also includes an edge sealing module having a sealant metering device, an edge sealing dispensing head, and an edge sealing dispensing nozzle. The device also includes a control device programmed with an algorithm to initiate gas filling substantially simultaneously with initiating edge sealing of the insulated glass unit and to complete the gas filling of the insulated glass unit prior to completion of the edge sealing.

Description:
CLAIM TO PRIORITY 
     This Application claims the benefit of U.S. Provisional Application No. 61/532,664, filed Sep. 9, 2011, entitled “APPARATUS FOR EDGE SEALING AND SIMULTANEOUS GAS FILLING OF INSULATED GLASS UNITS,” which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to the field of manufacturing insulated glass units. More specifically, the device relates to edge sealing of insulated glass units and gas filling of insulated gas units. 
     BACKGROUND OF THE INVENTION 
     Insulated glass is heavily utilized in modern residential and commercial construction. In many areas of the country it is required by building code as an energy conservation measure. A single pane of glass alone has very little insulating value. Multi-pane insulated glass windows have much greater insulating value. Insulated glass units (IGUs) generally include two panes of glass separated by a space. Sealants and adhesives are used to bond the glass panes to a perimeter spacer which separates the two panes of glass. The entire perimeter including the two panes of glass and the spacer are sealed to one another to eliminate movement of ambient air into the space between the two panes of glass. The space is filled with dehydrated air or more commonly another gas such as argon, xenon or krypton. Sulfur hexafluoride is also used for gas filling. The filling of insulated glass units with argon or another gas that is not air has been found to increase the energy efficiency of the insulated glass units markedly. Some insulated glass units includes three panes of glass with two intervening spaces which are similarly filled with argon or another gas other than air and then edge sealed. 
     Current technology includes a number of techniques for filling insulated glass units with gases other than air. According to some techniques, the insulated glass unit is assembled in a chamber filled with the argon or other gas, trapping the argon between the two panes and within the spacer. In other techniques, the insulated glass unit is preassembled, the argon or other gas is injected while air is removed and then the insulated gas unit is edge sealed. 
     In any case, the construction of insulated glass units generally involves the use of two separate manufacturing stations, two separate processes and two separate operators to gas fill and edge seal insulated glass units plus time utilized to do the separate operations. 
     SUMMARY OF THE INVENTION 
     The present invention solves many of the above-discussed problems. The present invention includes a device and method of manufacturing insulated glass units that includes gas filling of the insulated glass unit simultaneously with edge sealing of the insulated glass unit. 
     An example embodiment of the invention generally includes an automated edge sealing apparatus along with an automated gas filling apparatus. A method according to an embodiment of the invention, includes beginning the edge sealing process at approximately the same time as beginning the gas filling process wherein the gas filling process is completed prior to completion of the edge sealing of the insulated gas unit. 
     In one example embodiment, the edge sealing and simultaneous gas filling device includes a fully automated edge sealing device and a gas filling device. The fully automated edge sealing device generally includes a table, a gantry, a traveler, a sealant dispensing head operably coupled to the traveler, a sealant supply and a sealant pump. 
     The table is configured to support the insulated glass unit being edge sealed and gas filled and generally includes a horizontal surface that may include a conveyor, an air table or a roller support system on which the insulated glass unit may be moved into position for edge sealing and gas filling. 
     The gantry generally extends over the table and may be supported on two ends thereof on moveable carriers, so that the gantry may travel along the length of the table in an X direction in a controlled fashion. The traveler is supported on the gantry in a moveable fashion so as to be moveable from one end of the gantry to the other in a controlled fashion in the Y direction. movement of the gantry and the traveler are computer controlled 
     The sealant dispensing head is coupled to and supported by the traveler so as to be moveable in the X and Y directions as well as to be rotatable or to support a nozzle that is rotatable to address each side of the insulated glass unit to be edged sealed. The sealant dispensing head includes or is coupled to a metering device that delivers a metered proportional amount of sealant per unit of distance traveled along the edge of the insulated glass unit to accomplish edge sealing and filling the perimeter space with sealant. 
     The sealant supply includes a vessel containing sealant which can be transported by the sealant pump through conduits to the sealant dispensing head. The sealant supply may include a time setting sealant, a two part sealant or a hot melt sealant. 
     In other example embodiments the edge sealing device generally includes a hand assist edge sealing device such as that manufactured by Erdman Automation of Princeton, Minn. the assignee of this application or a fixed head edge sealing device such as that disclosed in U.S. published patent application 2012/0118473 the contents of which are incorporated herein by reference. The IGU to be edge sealed and gas filled may also be held in a vertical or nearly vertical position during the edge sealing and gas filling process. 
     According to an example embodiment of the invention, the gas filling device generally includes a lance structure, a lance support movement structure, a gas supply and gas metering unit. Gases used in gas filling include argon, krypton, xenon and sulfur hexafluoride. 
     The lance structure is structured in such a way as to pierce the spacer at the perimeter of the insulated glass unit and to engage the perimeter spacer in a generally sealing relationship. In one embodiment, the lance structure may include a single lance design having a pair of coaxial gas channels therein. In this case, one of the coaxial gas channels provides a conduit through which argon or another gas is injected into the insulated glass unit and the other of the coaxial channels provides a passage through which air is extracted from the insulated glass unit. 
     A dual lance design of the lance structure includes a first lance defining a conduit via which argon or other gas is injected into the interior of the insulated glass unit and a second lance through which displaced air is extracted from the insulated glass unit. 
     Another embodiment of the invention includes a multiple lance design having more than two lances. In this design, more than one lance is used to inject gas into the insulated glass unit and/or more than one lance is used to withdraw displaced air from the insulated glass unit. 
     The lance structure is supported by a lance movement and support structure configured to move appropriately to align the lance with the perimeter spacer of the insulated glass unit for insertion and to advance the lance with sufficient force to pierce the perimeter spacer of the insulated glass unit. The lance support movement structure is located generally at the last corner of the insulated glass unit to be edged sealed thereby permitting maximum time for gas insertion and air extraction prior to completion of the edge sealing process. 
     The gas supply generally includes a pressure vessel containing the gas to be injected into the insulated glass unit. 
     The gas supply is coupled to the lance structure by a gas metering unit and appropriate gas conduits. The gas metering unit includes a regulator to control gas injection pressure and volume as well as appropriate valves to initiate or stop gas injection as well as a vacuum supply to accomplish air extraction as well as a regulator and valves to control the volume and rate of air extraction relative to the rate of gas injection. The gas metering unit controls gas injection and air extraction appropriately so as to prevent undue stress on the insulated glass unit which might lead to explosion or implosion of the insulated glass unit. Accordingly, the gas injection and displaced air extraction is balanced by the gas metering unit to maintain gas injection and air extraction at approximately equal kilometric rates thereby maintaining the pressure within the IGU at approximately atmospheric pressure. 
     The invention also includes a method of simultaneously edge sealing and gas filling an insulated glass unit. In one example embodiment, the invention includes placing an insulated glass unit on the table; inserting a lance structure through the perimeter spacer of the insulated glass unit; beginning gas injection and air extraction through conduits of the lance structure; metering the gas injection and air extraction to balance gas injection and air extraction to minimize stress on the insulated glass unit to minimize the risk of explosion or implosion of the insulated glass unit; beginning edge sealing of the insulated glass unit simultaneously with or shortly after beginning gas filling; completing the gas filling prior to completion of the edge sealing of the insulated glass unit; withdrawing the lance structure from the spacer of the insulated glass unit and completing edge sealing of the insulated glass unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an edge sealing and gas filling device according to an example embodiment of the invention; 
         FIGS. 2A-2C  depict a schematic sequential representation of an edge sealing and gas filling process according to example embodiment of the invention; 
         FIG. 3  is a schematic depiction of a multiple lance gas injection-displaced air extraction structure according to example embodiment of the invention; 
         FIG. 4  is schematic plan view of a coaxial lance gas injection-displaced air extraction structure according to example embodiment of the invention; 
         FIG. 5  is a is schematic elevational view of a coaxial lance gas injection-displaced air extraction structure according to example embodiment of the invention; 
         FIG. 6  is a perspective view of a gas injection-displaced air extraction structure according to example embodiment of the invention; 
         FIG. 7  is a side elevational view of the gas injection-displaced air extraction structure of  FIG. 6 ; 
         FIG. 8  is plan view of the gas injection-displaced air extraction structure of  FIG. 6 ; 
         FIG. 9  is a perspective view of an edge sealing and gas filling device according to an example embodiment of the invention; 
         FIG. 10  is a plan view of an edge sealing and gas filling device according to  FIG. 9 ; 
         FIG. 11  is an elevational view of an edge sealing and gas filling device according to  FIG. 9 ; and 
         FIG. 12  is a flow chart depicting a method of simultaneously gas filling and edge sealing an insulated glass unit according to an example embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a block diagram according to an embodiment of the invention is depicted. Edge sealing gas filling device  10  generally includes edge sealing module  12  and gas filling module  14 . 
     Edge sealing module  12 , according to one example embodiment of the invention, generally includes sealant supply  16 , sealant pump  18 , sealant metering device  20 , moveable sealant applicator head  22  and sealant nozzle  24 . Sealant supply  16  generally includes a container filled with a sealant. Sealants may include but are not limited to butyl rubber sealants, silicone sealants, two part epoxy based sealants and most commonly today, hot melt sealants. This list should not be considered to be limiting. 
     Sealant pump  18  is coupled to sealant supply  16  by appropriate conduits to receive sealant and coupled by further conduits to sealant metering device  20 . Sealant metering device  20  measures supplies a measured amount of sealant at a desired rate. Sealant metering device  20  may include a sealant metering device  20  as disclosed for example by U.S. Published application 2006/0011649. Sealant metering device  20  is coupled to moveable sealant applicator head  22  via appropriate flexible conduits. Sealant nozzle  24  is rotatably coupled to moveable sealant applicator head  22  and is configured to direct sealant into the edge space of an insulated glass unit for edge sealing of the insulated glass unit. 
     Gas filling module  14  generally includes gas source  26  and vacuum source  28  coupled to gas metering unit  30  and gas fill injector/displaced air extractor  32 . Gas source  26  generally includes a pressure vessel filled with a desired gas for filling insulated glass units. Generally the gas supplied is argon though other non-air gases may be utilized as well as discussed elsewhere in the this application. Gas source  26  is coupled to gas metering unit  30  by appropriate conduits. Vacuum source  28  may include a vacuum pump or other vacuum source and is coupled to gas metering unit  30  by appropriate conduits. Gas metering unit  30  generally includes appropriate regulators and valves for delivering a measured amount of non-air gas, such as argon, to gas filling injector/displaced air extractor  32  at a known controllable flow rate. Gas metering unit  30  also includes appropriate regulators and valves to provide vacuum to gas filling injector/displaced air extractor  32 . 
     Referring to  FIGS. 2A-6 , gas fill injector  34  may include gas fill lance  38 . Displaced air extractor  36  may include displaced air lance  40 . According to one embodiment of the invention, gas fill lance  38  and displace air lance  40  are located side by side and coupled to manifold  42 . In an example embodiment, gas fill lance  38  includes shaft  44  and piercer  46 . Displace air lance  40  includes shaft  48  and piercer  50 . Piercer  46  and piercer  50  are structured appropriately to pierce a spacer of an insulated glass unit without otherwise damaging the insulated glass unit. Piercer  46  and piercer  50  may be formed of metal or another material of sufficient rigidity and hardness to pierce the spacer when a force is applied axially to piercer  46  and piercer  50 . 
     Referring to  FIG. 3 , according to another embodiment of the invention, more than one of either or both of gas fill lance  38  and displace air lance  40  may be present coupled in fluid communication with manifold  42 . 
     Referring particularly to  FIGS. 4 and 5 , gas fill injector/displaced air extractor  32  may include coaxial lance  52 . Coaxial lance  52  may include center gas fill conduit  54  and annular extraction conduit  56 . The location of gas fill conduit  54  and extraction conduit  56  may also be reversed wherein extraction is accomplished through a center conduit and gas fill accomplished through an annular conduit. 
     Referring to  FIGS. 2A-2C , an insulated glass unit (IGU)  58 , gas fill injector/displaced air extractor  32 , and moveable sealant applicator head  22  and sealant nozzle  24  are schematically depicted. Referring to  FIG. 2A , at the beginning of a combination edge sealing gas filling process, moveable sealant applicator head  22  and sealant nozzle  24  are located at the lower right corner of the right side of IGU  58 . Gas fill injector/displaced air extractor  32  is located adjacent the bottom side of IGU  58  near the lower right corner. Gas fill injector/displaced air extractor  32  is advanced toward IGU  58  so that gas fill lance  38  and displaced air lance  40  pierce perimeter spacer  60  of IGU  58 . Referring to  FIG. 2B , gas fill lance  38  and displaced air lance  40  have been advanced and pierced perimeter spacer  60 . Inflow of gas filling  62  is depicted by an arrow while displaced air extraction  64  is depicted by another arrow annotated with these reference numerals. In this example embodiment, edge sealing via sealant nozzle  24  begins at approximately the same time as gas filling  62  and displaced air extraction  64 . Sealant nozzle  24  travels around the perimeter of insulated glass unit  58  in a counter clockwise direction supported by moveable sealant applicator head  22 . 
     Referring to  FIG. 2C , according to an embodiment of the invention, gas filling  62  and displaced air extraction  64  are completed prior to the arrival of sealant nozzle  24  at the location of gas fill injector/displaced air extractor  32 . 
     As depicted in  FIG. 2C , gas fill injector/displaced air extractor  32  is retracted prior to the arrival of sealant nozzle  24  at its location and sealant nozzle  24  completes the trip around the perimeter of insulated glass unit  58  completely edge sealing the unit. As sealant nozzle  24  passes the location at which gas fill injector/displaced air extractor  32  pierced perimeter spacer  60  sealant dispensed by sealant nozzle  24  closes and seals any openings created by the piercing of perimeter spacer  60  resulting in a completed gas filled insulated glass unit  58   
     Referring to  FIGS. 9-11 , edge sealing module  12  may include fully automated edge sealing device  66 . In one example embodiment, fully automated edge sealing device  66  includes table  68 , gantry  70  and traveler  72 . Fully automated edge sealing device  66  also includes sealant supply  16 , sealant pump  18 , sealant metering device  20 , and moveable sealant applicator head  22  coupled to traveler  72 . In another embodiment of the invention, edge sealing module  12  may include a fixed head edge sealing device or a manually operated edge sealing device, not depicted. 
     Referring to  FIGS. 6-8 , example gas fill injector/displaced air extractor  32  generally includes support assembly  74 , gas filler assembly  76  and lance block assembly  78 . 
     Support assembly  74  includes support bracket  80 , track  82 , slider  84  and linear actuator  86 . Support bracket  80  is adapted to couple to edge sealing module  12 , for example, by fasteners (not shown). Track  82  is coupled to support bracket  80  and engaged to slider  84 . Slider  84  is linearly movable on track  82 . Slider  84  is coupled to gas filler assembly  76 . Linear actuator  86  is coupled to support bracket  80  in a generally parallel orientation to track  82 . Linear actuator  86  may include, for example, a pneumatic or hydraulic cylinder or another form of actuator capable of moving in a linear fashion. 
     Gas filler assembly  76  is coupled to slider  84  and to linear actuator  86 . Slider  84  is slidably engaged to track  82 . In the depicted embodiment, gas filler assembly  76  generally includes horizontal plate  88 , vertical support  90  and lance block support  92 . Vertical support  90  is coupled to the lance block support  92  via vertical track  94  and vertical slider  96 . Vertical actuator  98  also drivably couples block assembly  78  to lance block support  92 . Vertical actuator  98  may include, for example, an electrical, pneumatic or hydraulic vertical actuator. 
     Lance block assembly  78  generally includes lance support plate  100 , lance support block  102  and lance assembly  104 . Lance support plate  100  is coupled at generally right angles to vertical track  94  which is operably coupled to vertical slider  96 . Vertical actuator fasteners  106  couple lance support plate  100  to vertical actuator  98 . Lance support block  102  is coupled to lance support plate  100  by for example, fasteners. Lance assembly  104  is slidably engaged to lance support block  102 . Lance support block  102  also includes gas supply/vacuum source coupler  108  and presents slide rod receivers  110 . 
     Lance assembly  104  generally includes small block  112 , large block  114 , slide rods  116  and lances  118 . As depicted, slide rods  116  are slidably engaged to slide rod receivers  110 . Slide rods  116  are also coupled to small block  112 , which in turn is coupled to large block  114 . Large block  114  in turn supports lances  118 . Slide rods  116  may further include slide rod stops  120  coupled thereto. 
     Referring particularly to  FIGS. 6 and 8 , lances  118  generally include piercing portion  122 , tubular portion  124  and mounting portion  126 . Tubular portion  124  presents gas aperture  128  in fluid communication with tubular portion  124 . Tubular portion  124  is further in fluid communication with gas supply coupler/vacuum source coupler. Gas metering unit  30  is coupled to lances  118  via appropriate conduits for gas supply and vacuum. 
     Referring to  FIG. 12 , The invention also includes a method of simultaneously edge sealing and gas filling insulated glass unit  158 . In one example embodiment, the invention includes placing insulated glass unit  58  on the table  68  of edge sealing device  66  annotated by reference numeral  130 ; inserting gas fill lance  38  and displaced air lance  40  through perimeter spacer  60  of insulated glass unit  58  annotated by reference numeral  132 ; beginning gas filling  62  through gas fill lance  38  and displaced air extraction  64  through displaced air lance  40  annotated by reference numeral  134 ; metering the gas filling  62  and air extraction  64  to balance gas filling  62  and air extraction  64  annotated by reference numeral  136  to minimize stress on insulated glass unit  58  to minimize the risk of explosion or implosion; beginning edge sealing of the insulated glass unit simultaneously with or shortly before or after beginning gas filling  62  annotated by reference numeral  138 ; completing gas filling  62  and displaced air extraction  64  prior to completion of edge sealing of insulated glass unit  58  annotated by reference numeral  140 ; withdrawing lances  118  from perimeter spacer  60  of the insulated glass unit  58  annotated by reference numeral  142  and completing edge sealing of the insulated glass unit  144  including sealing openings in perimeter spacer  60  created by lances  118  annotated by reference numeral  144 . 
     In operation, referring to FIGS.  1  and  2 A- 2 C, an insulated glass unit  58  is placed on table  68  of edge sealing device  66 . Insulated glass unit  58  may be positioned by a conveyor as depicted in  FIGS. 9-11 , such as by air table or by multidirectional rollers or otherwise. Insulated glass unit  58  is positioned so that, for example, a corner thereof is positioned near lance block assembly  78 . Lance assembly  104  is positioned by vertical actuator  98  to be aligned with perimeter spacer  60  so that lances  118  are generally centered on perimeter spacer  60 . Linear actuator  86  advances lances  118  while gas filler assembly  76  rides on track  82  and slider  84 . Once lances  118  pierce perimeter spacer  60 , gas filling metering unit  30  is activated so that gas from gas source  26  is injected into insulated gas unit  58  through gas fill lance  38  and displaced air is withdrawn from within insulated glass unit  58  by vacuum source  28  coupled through displaced air lance  40 . 
     Simultaneous with the gas filling operation, sealant metering device  20  is moved relative to insulated glass unit  58  to follow perimeter spacer  60 . Movable sealant applicator head  22  is placed adjacent to insulated glass unit  58  and sealant nozzle  24  is used to direct sealant from sealant supply  16  via sealant pump  18  and sealant metering device  20  to fill the edge of insulated glass unit  58 . 
     For example, movable sealant applicator head  22  can begin secondary edge sealing insulated glass unit  58  at a corner adjacent to the location at which lances  118  are inserted through perimeter spacer  60 . According to an embodiment of the invention, gas filling of insulated glass unit  58  is completed prior to edge sealing of insulated glass unit  58 . When gas filling is complete, linear actuator  86  is again activated to withdraw lances  118  from perimeter spacer  60 . Movable sealant applicator head  22  then completes its circuit around insulated glass unit  58  thus completing the edge sealing of insulated glass unit  58  and sealing off openings made by the passage of lances  118  through perimeter spacer  60 . 
     While this process has been described as involving fully automated edge sealing device  66 , edge sealing may also be accomplished simultaneously with gas filling by a hand assist edge sealing device or by a fixed head edge sealing device. In the case of a fixed head edge sealing device, lance assembly  104  is secured to insulated glass unit  58  while insulated glass unit  58  is moved and manipulated past the fixed head edge sealing applicator head. 
     During the gas filling process gas metering unit  30  controls the flow of gas from gas source  26  and the vacuum from vacuum source  28  to balance gas flow and extraction of displaced air so as not to cause implosion or explosion or excess stress on insulated glass unit  58 . 
     The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof; therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.