Insulating glass unit and a method and apparatus for filling and sealing same

An insulating gas unit, and a method and apparatus for filling and sealing the insulating gas unit with an insulating gas, such as argon or krypton. The insulating glass unit includes a spacer frame having at least one elongated or oblong opening dimensioned to receive a gas filling nozzle. A mating elongated or oblong plug is dimensioned to be received within the opening in order to seal the insulating space of the insulating gas unit. A dimpling tool engages with the plug to form dimples that secure the plug in the opening.

FIELD OF THE INVENTION

The present invention relates generally to the manufacture of insulating glass units, and more particularly to an insulating gas unit, and a method and apparatus for filling and sealing same.

BACKGROUND OF THE INVENTION

A typical insulating glass (IG) unit is generally comprised of two panes of glass separated by a metal spacer (also referred to as a spacer frame) that holds the two glass panes together, forming an insulating space therebetween. An insulating gas (e.g., argon, krypton, etc.) is injected into the insulating space between the two glass panes to provide the IG unit with desired insulating properties. One or two gas filling holes may be provided in the spacer that separates the two glass panes to facilitate filing of the insulating space with insulating gas.

The process of filling an IG unit with insulating gas can be a slow process, the speed of which is influenced by how quickly the volume of gas in the IG unit can be exhausted. Gas filling is done by one of two methods, namely, laminar or dilution filling.

Laminar filling is a method of filling the insulating space of the IG unit with insulating gas by means of a laminar flow. Two holes are needed in the spacer that is located between the two panes of glass, i.e., one hole located at the bottom of the spacer and one hole located at the top of the spacer. Insulating gas is injected through the bottom hole of the spacer in a laminar flow that induces a boundary layer between the insulating gas and the air located in the insulating space. As the insulating gas (which is heavier than air) fills the insulating space, it displaces the air that exits through the top hole of the spacer. The rate at which the insulating gas can be injected into the insulating space is determined by how fast air can be exhausted from the insulating space, as limited by a filling speed that prevents excess turbulence that will disrupt the laminar nature of the gas flow. A sensor “sniffs” the air and gas exhausted from the insulating space through the top hole to determine an insulating gas concentration. When the sensed insulating gas concentration reaches a predetermined concentration, the gas filling cycle ends.

Dilution filling is a method of filling the insulating space of the IG unit with insulating gas by injecting the insulating gas at a high fill rate that causes the insulating gas to mix with the air inside the insulating space, and exchange the air inside the insulating space with the insulating gas. Typically, dilution filling is done with a single hole located at the top of the spacer. By inserting the insulating gas into the insulating space through the hole in the top of the spacer, the insulating gas mixes with the air inside the insulating space. A sensor “sniffs” an insulating gas/air mixture exhausted from the insulating space through the hole in the spacer to determine the insulating gas concentration. When the insulating gas concentration reaches a required concentration, the gas filling cycle ends. Since dilution filling results in the mixing of the insulating gas and air inside the insulating space there is a significant waste of insulating gas. In this respect, it is usually necessary to fill the insulating space with a volume of insulating gas that is at least three times the volume of the insulating space in order to reach the required insulating gas concentration exhausted from the insulating space.

With each of the above-described gas filling methods, the determining factor of how fast an insulating space can be filled is related to how quickly the insulating gas can be injected into the insulating space. Although insulating gas can be inserted faster using the dilution filling method, as compared to the laminar filling method, the insulating gas can only be inserted as quickly as the gas/air mixture can be exhausted from the insulating space through the exhaust hole. A vacuum pump can be used assist to exhaust the gas/air mixture from the insulating space. In this respect, the vacuum pump induces a vacuum at the exhaust hole to draw the gas/air mixture out of the insulating space at an increased flow rate. With an increased flow rate for exhausting the gas/air mixture, the gas insertion flow rate can be increased. However, even with a perfect vacuum, the rate at which the gas/air mixture is exhausted from the insulating space is limited by the orifice size of the exhaust hole.

Holes are typically formed in a spacer by punching or drilling a 3 mm or 4 mm diameter round hole, depending upon the size/width of the spacer. The size of the hole is limited by the size/width of the spacer. Smaller spacer widths do not accommodate a larger hole, because the hole will consume most of the spacer width and decrease the structural integrity of the spacer. Larger sized holes can be punched/drilled, but only on wider spacers. However, since tooling is not easily changed, manufacturers typically select a hole size based on the smallest sized spacer being used. Thus, it is estimated that more than 95% of manufacturers currently employ tooling having a 3 mm or 4 mm diameter punch/drill. A much smaller percentage of manufacturers currently employ tooling providing a 5 mm diameter punch/drill to form 5 mm diameter round holes. Limits on hole size result in limits on the flow rate for exhausting air and gas from the insulating space.

In order to retain the insulating gas inside the insulating space after the filling process, it is necessary to properly seal the spacer hole(s). Currently, IG units are being commercially produced with spacers having conventional round gas filling holes, because plugs are known which close such spacer holes. These plugs serve multiple functions, namely, locking together the ends of an assembled spacer, and retaining the gas inside the insulating space in a marginally gas tight manner. At present, holes in the spacer are sealed with a plug taking the form of a screw or a closed end round rivet. Both of these types of plugs have drawbacks. In this respect, screws lack a reliable airtight seal, while rivets require special tools to install in the hole.

As a result of slow gas filling speeds, the gas filling step tends to become a bottleneck in the process of manufacturing IG units. These bottlenecks can become costly to manufacturers. To address this situation, manufacturers will often take a single flow of IG units off of a production line and route them through multiple gas filling stations. This is a labor intensive process, and a highly manual process, that is subject to quality and capacity variances.

The present invention provides a method and apparatus for filling and sealing insulating glass units that addresses these and other drawbacks currently existing in the field of IG unit manufacturing.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided n insulating glass unit comprising: a spacer frame having at least one oblong opening formed therein; two panes of glass connected to opposite sides of a spacer frame to form an insulating space therebetween; and at least one oblong plug dimensioned to be received by the at least one oblong opening.

In accordance with another aspect of the present invention, there is provided a method for filling and sealing an insulating glass unit having an insulating space located between a pair of glass panes spaced apart by a spacer frame. The method comprising: forming an oblong-shaped opening in the spacer frame; inserting a gas filling nozzle through the opening to inject insulating gas into the insulating space; removing the gas filling nozzle from the opening after injection of the insulating gas; inserting an oblong-shaped plug into the opening to seal the insulating space; and securing the plug in the opening by forming one or more dimples in the plug.

In accordance with another aspect of the present invention, there is provided a dimpling tool for locking a plug within an opening to seal an insulating space of an insulating glass unit. The dimpling tool comprises: an engagement portion including: (a) a stem; and (b) a head located at a distal end of the stem and extending transverse thereto, wherein the head is comprised of: (i) a pair of opposing flat sides, and (ii) a pair of opposing convex curved sides.

In accordance with yet another aspect of the present invention, there is provided a gas filling nozzle for filling an insulating space of an insulating glass unit with insulating gas. The gas filling nozzle comprises: an interface portion adapted for fluid connection with a vacuum source, a pressure sensing device, and an insulating gas supply; and an insertion portion dimensioned to be inserted through an opening to the insulating space, wherein the insertion portion includes: (i) a vacuum tube fluidly connected to the vacuum source, (ii) a pressure monitor tube fluidly connected to the pressure sensing device, and (iii) a gas supply tube fluidly connected to the insulating gas supply.

An advantage of the present invention is the provision of an IG unit and a method and apparatus for filling and sealing same that allows for faster and lower cost manufacturing of IG units.

Another advantage of the present invention is the provision of an IG unit and a method and apparatus for filling and sealing same that improves retention of insulating gas within the insulating space of the IG unit.

Another advantage of the present invention is the provision of an insulating gas unit and a method and apparatus for filling and sealing same that reduces the amount of time needed to fill the insulating space of the IG unit with insulating gas.

Still another advantage of the present invention is the provision of an insulating gas unit and a method and apparatus for filling and sealing same that allows for increased automation of the gas filling process.

Still another advantage of the present invention is the provision of an insulating gas unit and a method and apparatus for filling and sealing same that provides an improved gastight seal of the insulating space.

Yet another advantage of the present invention is the provision of an insulating gas unit and a method and apparatus for filling and sealing same that allows for continuous inline processing and increased automation in the manufacture of IG units.

These and other advantages will become apparent from the following description of illustrated embodiments taken together with the accompanying drawings and the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein the showings are for the purposes of illustrating an embodiment of the invention only and not for the purposes of limiting same,FIG. 1shows a U-shaped spacer bar20, according to an embodiment of the present invention. Spacer bar20is bent to form a rectangular spacer frame30(FIGS. 2 and 3) of an IG unit10(FIG. 14). Spacer bar20is generally comprised of a pair of side walls21and a center wall23. Walls21and23provide a U-shaped cross-section, and define an inner channel25. A plurality of notches22are formed in side walls21to facilitate bending of spacer bar20in a spacer frame. Furthermore, slots24are respectively formed in center wall23at first and second ends26,28of spacer bar20. In the illustrated embodiment, notches24are oval-shaped, and more specifically are stadium-shaped (i.e., a “discorectangle” consisting of a rectangle with semicircles at opposite ends), as best seen inFIG. 2. For example, slots24may have dimensions of approximately 3 mm (width)×12 mm (maximum length) or 4 mm (width)×12 mm (maximum length). It should be appreciated that the illustrated discorectangular shape of slots24is an exemplary shape according to an embodiment of the present invention. It is contemplated that slots24may also take the form of alternative elongated or oblong shapes (e.g., a rectangle). Spacer bar20may be made of such materials, including, but not limited to, stainless steel or tin plate steel.

Spacer bar20shown inFIG. 1is bent at notches22to form rectangular space frame30shown inFIGS. 2 and 3. Spacer frame30haste side sections36a,36b,36c,36dand corners32a,32b,32c,32d. First end26is joined to second end28by aligning slots24to form an opening34. Thus, opening34has substantially the same shape and dimension as slots24. As seen inFIG. 3, spacer frame30of the illustrated embodiment is rectangular-shaped having long sides36c,36dand short sides36a,36b. Channel25extends along the inner perimeter of spacer frame30. It should be appreciated that while the present invention is described with reference to a rectangular-shaped spacer frame30, it is contemplated that spacer frame30may be configured in alternative shapes to accommodate IG units of different shapes and dimensions.

In accordance with the present invention, an alignment clip120is provided to maintain alignment of slots24during assembly of IG unit10shown inFIG. 14. With reference toFIG. 2, alignment clip120is generally comprised of a pair of legs122aand122bthat are connected to each other by a front end portion126. Legs122aand122bare biased away from each other, but will flex toward each other when pinched together. Front end portion126is dimensioned to be inserted through opening34when legs122aand122bare pinched together. When legs122aand122bare released, the distance between legs122aand122bincreases and thereby temporarily locks alignment clip120within opening34, as shown inFIG. 3. When alignment clip120is locked within opening34, respective engagement sections124a,124bof legs122a,122bengage with spacer frame30. It will be appreciated that alignment clip120maintains alignment of slots24and keeps first end26connected to second end28. Alignment clip120is removable from opening34by pinching legs122aand122btoward each other to release engagement sections124a,124bfrom engagement with spacer frame30.

FIGS. 4-6show a plug50according to an embodiment of the present invention. Plug50is dimensioned to be press fit into opening34to seal insulating space190of IG unit10, as will be described with reference toFIGS. 15-17. Plug50has an oblong-shaped bottom wall52, an annular oblong-shaped side wall54extending upward from bottom wall52, and an annular flange60extending outward from the upper end of side wall54. The shape and dimensions of bottom wall52and side wall54are substantially the same as opening34.

In the illustrated embodiment bottom wall52is stadium-shaped (i.e., a “discorectangle” consisting of a rectangle with semicircles at opposite ends) and side wall54has a matching stadium-shaped cross-section that is tapered such that the perimeter of side wall54decreases from the upper end of side wall54to the bottom end of side wall54, as seen inFIG. 6. An inner recess58is defined by bottom wall52and side wall54. According to an alternative embodiment of the present invention, side wall54of plug50is not tapered, and thus has a substantially constant perimeter from the upper end of side wall54to the bottom end of side wall54.

In the illustrated embodiment flange60is angled relative to the horizontal to provide a spring action when plug50is fully inserted into opening34. This spring action provides an improved seal of opening34. As seen inFIG. 6, angle α of flange60is in the range of approximately 1-5 degrees, and preferably about 3 degrees.

Plug50is preferably made of a metal, such as stainless steel or tin plate steel. It is contemplated that the plug50may be dimensioned to be received within elongated or oblong openings of various shapes and dimensions, including but not limited to, dimensions of approximately 3 mm×12 mm, 4 mm×12 mm, 3 mm×10 mm, and 5 mm×12 mm (“width×maximum length”). It is also contemplated that in accordance with an alternative embodiment, plug50may be shaped and dimensioned to seal a conventional round gas filling hole.

Referring now toFIGS. 7, 7A, 8 and 9, there is shown a dimpling tool70according to an embodiment of the present invention. Dimpling tool70is used to form one or more dimples in side wall54of plug50in order to lock plug50in opening34, as will be described in detail below. Dimpling tool70is generally comprised of a handle bar72, a rod74, and a T-shaped engagement portion80. In the illustrated embodiment, handle bar72extends through an opening formed at the upper end of rod74to provide a handle portion adapted to be gripped by a user to rotate dimpling tool70, as will be described below. Engagement portion80extends outward from the lower end of rod74. Engagement portion80includes a stem84and a head90located at the distal end of stem84and extending transverse thereto, as best seen inFIG. 7A. Head90includes a pair of elongated flat sides92and a pair of convex curved sides94. Curved sides94provide contact surfaces for forming dimples in side wall54of plug50, as will be discussed below.

It should be understood that dimpling tool70is intended for “manual” user operation (i.e., rotation by hand). However, it is contemplated that engagement portion80may also be formed at a distal end of a conventional drill bit for use with a power tool. Operation of the power tool may be automated by a computer control unit that controls an automated assembly process.

FIGS. 10-13show a gas filling nozzle100according to an embodiment of the present invention. Gas filling nozzle100is adapted for filling insulating space190of IG unit10with insulating glass through opening34of spacer frame30. Gas filling nozzle100is generally comprised of an interface portion102and an insertion portion104. Interface portion102is adapted for fluid connection (via hoses) with a vacuum source (not shown), a pressure sensing device (not shown), and an insulating gas supply (not shown), such as an argon or a krypton gas supply. Insertion portion104is dimensioned to be inserted through opening34of spacer frame30, as shown inFIG. 14.

Insertion portion104includes a vacuum tube110, a pressure monitor tube112, and a gas supply tube114. In the illustrated embodiment, gas supply tube114includes a plurality of side orifices116at distal end108of nozzle100. Vacuum, pressure monitoring, and gas supply channels are defined by tubes110,112, and114. Corresponding channels also extend through interface portion102. Accordingly, continuous fluid conduits are provided for vacuum, pressure monitoring, and gas supply between the proximate end106and the distal end108of nozzle100, as seen inFIGS. 10 and 11. In the illustrated embodiment, outer surfaces of tubes110,112, and114define an oblong shape that matches the shape and dimensions of opening34, as best seen inFIGS. 13 and 14.

Referring now toFIGS. 14-17, a method of assembling, filling, and sealing insulating glass unit10according to an embodiment of the present invention will now be described. It should be understood that IG unit10is an exemplary IG unit that is generally comprised of two glass panes200separated by spacer frame30that holds the two glass panes200together, thereby forming an insulating space190therebetween.

Beginning with assembly of spacer frame30, spacer bar20(FIG. 1) is shaped into spacer frame30by bending the spacer bar20at notches22to form right-angle corners32a,32b,32c,32dof spacer frame30(FIGS. 2 and 3). Slots24, formed at opposite ends26,28of the spacer bar20, are aligned to form opening34. Thereafter, alignment clip120may be optionally locked within opening34to connect ends26,28and to maintain slots24in alignment (FIG. 3). Next, a sealant180(such as hot melt butyl) is applied to the outer surface of spacer frame30, except in the vicinity of opening34, as best seen inFIG. 14.

A pair of glass panes200are positioned at opposite sides of spacer frame30. Thereafter, glass panes200are pressed against spacer frame30while heating in an oven, as is known to those skilled in the art.

After completion of this portion of the assembly process, alignment clip120is removed from opening34, and insertion portion104of gas filing nozzle100is inserted through opening34into insulating space190(FIG. 14). Interface portion102of nozzle100is fluidly connected with (i) a vacuum source, (ii) a pressure sensing device, and (iii) a supply of insulating gas (e.g., argon or krypton gas). Accordingly, insulating gas is injected into the insulating space190via gas supply tube114. Simultaneously, a vacuum is applied through vacuum tube110to draw air and gas out of insulating space190, and the pressure sensing device monitors the pressure in insulating space190via pressure monitor tube112.

A computer control unit (not shown) is provided to control the flow of insulating gas through gas supply tube114, control the vacuum applied via vacuum tube110, and to analyze data obtained by the pressure sensing device. It is desirable to apply as large a vacuum as possible, but always maintain a slightly positive pressure in insulating space190by rapidly adjusting the flow of incoming gas via gas supply tube114. The air and gas removed from insulating space190via vacuum tube110is fed to a conventional gas analyzer (not shown) to monitor the gas concentration. Data from the gas analyzer is supplied to the computer control unit.

A gas filling operation is completed after a predetermined insulating gas concentration is reached in insulating space190that achieves a desired insulating property for IG unit10. After the gas filling operation is completed, gas filling nozzle100is removed from opening34and plug50is rapidly press fit into opening34to seal insulating space190. The spring action of flange60of plug50provides a tight seal around opening34.

With reference toFIG. 15, engagement portion80of dimpling tool70is inserted into recess58of plug50, such that the front face of rod74contacts the top face of flange60. Engagement portion80is oriented in recess58such that elongated flat sides92of head90are generally aligned with the longitudinal direction of recess58, as shown inFIG. 15. Next, dimpling tool70is rotated approximately 90 degrees to respectively engage the pair of convex curved sides94of head90with opposing inner surfaces of side wall54to thereby form a pair of dimples64therein (FIG. 16). Since the distance between the pair of convex curved sides94is greater than the distance between the opposing inner surfaces of side wall54, the convex curved side walls94will cause two opposite facing portions of side wall54to bulge outward during rotation of dimpling tool70, thereby forming a pair of opposite facing dimples64, as best seen inFIG. 17. Dimples64lock plug50within opening34, as best seen inFIG. 16. Locking of plug50within opening50prevents removal of plug50from opening34, fastens end26to end28, and closes opening34to seal insulating space190.

Dimpling tool70is removed from recess58by again rotating dimpling tool70approximately 90 degrees. It will be appreciated that a second pair of opposite facing dimples64can be formed by repeating the steps described above at a second position within recess58.FIG. 17illustrates a plug50that is secured within opening34by formation of first and second pairs of opposite facing dimples64using dimpling tool70in the manner described above.

After completing formation of dimples64and removing dimpling tool70from recess58, additional sealant180is applied to spacer frame30over plug50and the region surrounding plug50. Sealant180minimizes gas and moisture transmission through opening34.

It should be appreciated that the present invention provides significant advantages over the prior art. In this respect, the elongated or oblong shape of the opening in the spacer frame increases the area of the opening, without increasing the width of the opening. As a result, more gas and air can flow through the opening than in prior art IG units. This allows the gas filling process to be completed in a shorter period of time, thereby increasing the manufacturing speed of IG units. With a larger opening area, it is also easier to automate the gas filling process. In this respect, there is a greater margin of error for misalignment of the slots forming the opening, and a greater margin of error for misalignment of the gas filling nozzle with the opening.

The foregoing describes specific embodiments of the present invention. It should be appreciated that these embodiments are described for purposes of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. For example, the present invention has been illustrated by an IG unit having a single opening in the spacer frame for gas filling. However, the IG unit may include a plurality of openings in the spacer frame for gas filling. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.