Methods and apparatus for evaluating insulating glass units
An apparatus and method for measuring the color and gas fill concentration of insulating glass units is disclosed. One apparatus includes a color measuring device and gas fill concentration measuring device coupled to a production line for manufacturing insulating glass units. One method of the invention involves measuring the color and gas fill concentration of insulating glass units after they have been filled with gas and sealed.
This application is a continuation of application Ser. No. 10/875,640 filed Jun. 24, 2004, which claims the benefit of U.S. Provisional Application No. 60/482,127 filed Jun. 24, 2003.
The entire disclosure of the above mentioned application is hereby incorporated by reference.
FIELD OF THE INVENTIONThe present disclosure relates generally to methods and devices for evaluating insulating glass units in a production environment and in situ. More particularly, the present disclosure relates to methods and devices for evaluating the optical properties of insulating glass units.
BACKGROUND OF THE INVENTIONInsulating glass units (IGUs) are typically composed of two parallel glass panes spaced apart by a peripheral spacer. Spacers are typically made of metal, usually of tubular configuration, and are formed so as to have two flat sides that face the confronting surfaces of the glass panes. The spacers are bent so as to conform to the periphery of the glass panes. Typically, the spacers are adhered to the glass panes with a sealant that is gas-impermeable, such polyisobutylene. An additional sealant, with strong adhesion force, such as silicone, is commonly applied around the outside edges of the IGU. For aesthetic purposes, muntins may be sandwiched between the panes to give the unit a divided light appearance. To improve thermal resistance across the glass assemblies, the space between the panes of glass, or interpane space, may be filled with an insulating gas such as argon. To perform adequately, the IGU must be filled with a proper amount of gas. Typically, the amount of gas flowed into the interpane space is gauged by flowing gas at a known rate for a specified period of time into the IGU.
Often, at least one pane surface of an insulating glass unit is coated with a low energy coating to prevent conduction of heat through the glass. These coatings can result in the reflectance of color from the glass surface. Typically, color reflectance is undesirable. Therefore, for aesthetic purposes, it is desirable to manufacture glass and IGUs that reflect at wavelengths in the blue or blue/green range.
In the manufacture of insulating glass units, uniform production lines are often used to produce large quantities of glass assemblies. In a typical production line, glass panes are transported to a conveyor with rollers on a vertical platen that transports the panes to a number of stations where various steps of the assembly process are performed.
In terms of quality assuring the reflected color of an IGU, for example, the methods have generally involved measuring the transmitted color of a coated glass pane before it is assembled into an IGU. Similarly, the gas fill concentration is typically quality controlled by procedures involving methods that destroy the IGU after the IGU has been fully assembled and removed from the production line. Therefore, materials are wasted and each unit cannot be quality assured.
It would be desirable therefore, to provide a quality control method that is capable of quality assuring each IGU produced in a non-destructive manner. Furthermore, to reduce costs, it would be desirable to provide an automated or semi-automated system on a production line that can quickly and accurately quality assure IGUs as they are manufactured without sacrificing materials, time, and labor expenses.
The IGU 10 illustrated in
Typically, the spacer 18 is formed of metallic tubing (e.g., aluminum, stainless steel and others). This tubing can be provided in a variety of cross-sectional configurations. Examples of spacers that may be suitable in some applications are disclosed in U.S. Pat. Nos. 5,377,473; 5,439,716; 5,679,419; 5,705,010, and 5,714,214, the entire teachings of each of which are incorporated herein by reference. It is also noted that a variety of conventional spacer designs are commercially available from Alumet Manufacturing, Inc., which is located in Marysville, Wash., U.S.A.
Regardless of the particular spacer configuration, the spacer characteristically includes two generally opposed lateral surfaces that are adapted to be bonded respectively to the peripheral inner surfaces of the panes. Bonding the spacer to both panes desirably forms a gas-tight seal that prevents air and other gases from entering and/or escaping the interpane space. The interior of the spacer desirably carries a deposit of desiccant 19 (best shown in
The sealing system of an IGU 10 desirably minimizes gas flow between the gas space inside the unit and the ambient environment outside the unit. While some IG units have only a single seal, other IG units typically include two seals: a primary or “first” seal 22 and a secondary or “second” seal 24, better illustrated in the cross section of
The interpane space 14 of an IGU 10 can be advantageously filled with an insulative gas. It is to be understood that the term insulative gas is used herein to refer to any gas that is a better thermal insulator than air. For example, a gas is to be considered insulative if it has a lower thermal conductivity than air, and hence reduces (relative to an IGU containing air) heat transfer by conduction. A gas is also to be considered insulative if it is heavier than air, and hence reduces (relative to an IGU containing air) heat transfer by convection. For example, argon is a preferred insulative gas since it is both less thermally conductive and heavier than air. Other inert gas fills can be used as well. Argon, krypton, and other inert gases are commercially available from a number of suppliers, including BOC Gases (Murray Hill, N.J., and U.S.A.), Air Products and Chemicals, Inc. (Allentown, Pa., U.S.A.), and Air Liquide America Corporation (Cambridge, Md., U.S.A.).
IGUs of standard size can be assembled on IGU production or assembly lines.
It is to be understood that the following description of an IGU production is illustrative only and the invention is not limited to use on a production line generally or to use on any particular production line. The assembly line and assembly stations described herein may be varied with the addition or deletion of various stations.
The glass panes are typically manually loaded onto a conveyor 26 that transports the panes and partially assembled units to various stations for processing. The conveyor 26 may be comprised of a generally horizontal belt or other suitable solid surface to support the bottom surface of the glass panes or partially assembled units. A generally vertical platen 28 with a plurality of rollers 30 for vertical support and propulsion of the panes or partially formed propels the glass panes or partially formed IGUs through the production line.
In an illustrative production line, for example, the glass panes may be conveyed to a variety of stations including, for example, an edge deletion station where, if present, the coating on the glass is removed from the perimeter of the pane. The edge deleted glass pane may then be conveyed to a washing station to remove any debris or unwanted material from the surface of the pane. A gas-impermeable sealant is applied to the edges of a spacer dimensioned to the particular configuration of the IGU are adhered to the periphery of the one pane of a pair of panes.
Pairs of panes, one pane with a spacer adhered and a bare pane may be next conveyed to an assembly station (not shown) where the pairs are mated and joined together through the exposed primary sealant on the edge of the spacer opposing the edge adhered to the glass pane.
The partially assembled IGUs are then conveyed to a gas-fill station where typically, an insulating gas is inserted into the interpane space and the unit is sealed. One exemplary mechanism for filling IGUs is disclosed in U.S. Pat. No. 5,957,169, the entire disclosure of which is hereby incorporated by reference.
A color change produced by the coated substrates of the IGU may be measured by using devices that transmit light that has a known wavelength distribution over the visible spectrum. The light from the source may strike the coated substrate at an angle that is generally perpendicular to the surface of the substrate. A light detector may measure the light intensity at various wavelengths across the visible spectrum and compare these measurements to the known wavelength distribution of the source to determine one or more optical characteristics of a sample being evaluated
Color measuring station 32 of figure for comprises a color measuring device 34. Color measuring device 34 may comprise various instruments without deviating from the spirit and scope of the present invention. Examples of instruments that may be suitable in some applications include calorimeters and spectrophotometers. For example, an apparatus in accordance with some embodiments of the present invention may comprise various commercially available spectrophotometers. One spectrophotometer that may be suitable for some applications is commercially available from Minolta Camera company of Osaka, Japan which identifies it with the model number CM-2500D. Color measuring instruments are described in a number of U.S. patents, including: U.S. Pat. Nos. 4,397,533; 4,402,611; 4,917,495; 4,995,727; 5,168,155; 5,214,494; 5,432,609; 5,570,192; 5,592,294; 5,831,740; 5,859,709; 5,963,334; 5,978,606; 6,020,959; 6,088,117; 6,462,819; 6,614,518; and 6,707,553. The entire disclosure of each U.S. patent listed above is hereby incorporated by reference.
Color measuring device 34 can be coupled to the production line by any suitable means. For example, as shown in
In some embodiments of the present invention, a reflecting surface may be provided on a surface opposing the detector. For example, a reflecting tile 38 may be provided on the vertical platen 28 in alignment with the detector of the color measuring device 34.
Coatings are typically applied to the #2 surface of panes, which is the interior surface of the pane of glass facing the exterior of the building. The coating often results in the reflectance of color to the eye of an observer. Such coloration can be problematic and detract from the architectural beauty of a building. Generally, it is desirable to provide IGUs that are aesthetically pleasing to people observing the exterior of the building into which the IGU is incorporated. Therefore, advantageously, in practicing the invention, according to any embodiment, the glass sheets may be loaded onto the production line so when the IGU 10 reaches the color measuring station 32, the IGU 10 is positioned so that the device for measuring color 34 detects the transmitted color from the #2 surface through the #1 surface. In this configuration, the color visible from the exterior of the building will be monitored.
In operation, as an IGU 10 enters the station 32 it is positioned so that a portion of the glass surface 12 is aligned with the color measuring device. The extendable member 36 moves towards the IGU 10 and contacts the glass pane 12 closest to it with the soft surface (not shown). The extendable member 36 stabilizes the IGU 10 against the vertical platen 28 while the reading is made. The color measuring device 34 emits radiation towards the IGU. This radiation travels through the panes 12 and 12′ and space 14 until it reaches the tile 38. The radiation striking the tile 38 is reflected back to a detector on the color measuring device 34 and the appropriate correlations are made.
The gas fill concentration measuring device 40 may be secured to the production line in any matter suitable to bring it into proximity to the IGU 10 to be measured. For example, the device 40 may be attached to an extendable arm 36, similar to the color measurement device, provided adjacent to the production line. The extendable arm 36 may be movable perpendicularly with respect to the surface of a glass pane 12 of the IGU 10 so that it may move into proper position to take the reading.
When an IGU reaches the station, the extendable member 36 is activated and moves toward the IGU 10 bringing the gas fill concentration measuring device 40 into contact with the surface of the glass pane 12 of the IGU 10. The gas fill concentration measuring device 40 may include a means for engaging the glass surface, for example a suction cup, so that a measurement may be initiated. After the measurement is made, the IGU 10 is conveyed out the station 42 or alternatively, is manually removed.
The color measuring device 34 and gas fill concentration sensor 40 may be mounted to an extendable arm 48 coupled to the conveyor 26 adjacent to the IGU 10. A reflecting tile 38 may be provided on the vertical platen 28 in alignment with the color measuring device to facilitate the measurement as previously described. The extendable arm 48 may include an engaging surface for contacting and stabilizing the IGU while the measurements are taken.
In an alternative embodiment, the color measuring device is mounted to the vertical platen 28 and a color reflecting tile 38 is mounted on the extendable member 48 in alignment with the color measuring device 34 and the gas fill concentration sensor 40 is mounted on the extendable member 48 (as described above).
Positioning the station at a location downstream from the gas fill station provides the advantage of measuring the gas fill concentration and color of IGUs after complete assembly but before any masking material, which may interfere with measurements, is applied to the IGU.
Reductions in manual labor and time required necessary to produce IGUs is desirable as cost reducing measures. Providing a dual color and gas fill measuring station on the IGU production line allows for efficient, time effective manufacture and quality assurance. Both the reflected color and gas fill can be evaluated at a single stop, reducing production costs by automating quality assurance procedures and reducing the time required to carry out the procedure. The stop period, that is, the time an IGU will spend at the color and gas fill concentration center, is preferably less than 30 seconds and more preferably is in the range of 10-20 seconds.
The data obtained from the measuring devices according to any embodiment described herein, can be captured and transmitted to a database 50. The measuring devices 34 and 40 may be coupled to the data base 50, for example, a personal computer or alternatively the data may be transmitted telemetrically. The stored data can be used for a variety of purposes. For example, stored data can be used for quality control to monitor the retention of gas within the IGU. The gas concentration of an IGU can be measured at any time subsequent to manufacture and compared against the concentration at the time of manufacture to determine whether the IGUs are properly retaining the gas. The stored data may be used for a variety of other purposes as is appreciated by the skilled artisan.
As shown in
First light source 70 may comprise various light sources without deviating from the spirit and scope of the present invention. In the embodiment of
In the embodiment of
In
Generators are described in a number of U.S. patents, including: U.S. Pat. Nos. 5,303,139; 6,538,388; 6,567,278; 6,586,887; 6,727,654; 5,712,592; and 6,750,614. The entire disclosure of each U.S. patent listed above is hereby incorporated by reference.
In the embodiment of
In the embodiment of
In some embodiments of the present invention, computer 100 may decide to accept or reject insulating glass unit 54 based upon both first signal 102 and second signal 104. For example, computer 100 may be capable of comparing first signal 102 with a first acceptable range and comparing second signal 104 with a second acceptable range. Computer 100 may then generate a reject signal if first signal 102 is outside the first acceptable range or if second signal 104 is outside the second acceptable range.
In some embodiments of the present invention, computer 100 may be capable of correcting second signal 104 to compensate for a color change that occurs in second light emission 80 as it passes through a single pane of insulating glass unit 54. For example, computer 100 may use a color change that occurs in light from first light emission 78 as it passes through first pane 56 and second pane 58 a first time and a second time. The color change may be calculated by comparing a known color of light emitted by first light source 70 to the color of light received by first photosensor 72. This comparison may include adding and/or subtracting color components. The color of light received by second photosensor 76 may be determined from second signal 104. One quarter of the color change may be subtracted from and/or added to the color of light received by second photosensor 76 to correct for a color change that occurs in second light emission 80 as it passes through a single pane of insulating glass unit 54.
While a preferred embodiment of the invention has been disclosed, it should be understood that various changes, adaptations, and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims.
Claims
1. A device for testing insulating glass units in a production line environment, comprising:
- a conveyer for transporting the insulating glass units to stations located along the production line; and
- a gas fill concentration sensor located at one of the stations located along the production line, the gas fill concentration sensor being supported on a robotically controlled supporting member operative to bring the gas fill concentration sensor into close proximity of or contact with the insulating glass units without damage to the insulating glass units and retracting the gas fill concentration sensor from the vicinity of the insulating glass units to permit conveyance of the insulating glass units to the station and from the station wherein the gas fill concentration sensor measures the gas fill concentration of the insulating glass units delivered to that station.
2. The system of claim 1, further comprising an extendable member located at the station with the gas fill concentration sensor wherein the extendable member contacts and secures the insulating glass unit while the gas fill concentration is measured.
3. The system of claim 1, wherein the extendable member is movable in at least an X or Y axis relative to the insulating glass unit.
Type: Application
Filed: Feb 16, 2007
Publication Date: Oct 9, 2008
Inventors: Niklas Tornkivst (Espoo), Mats Therman (Helsinki), Paul Trpkovski (Loganville, WI)
Application Number: 11/707,621
International Classification: G01N 37/00 (20060101);