Patent Application
20120118473
The invention relates to edge sealing of insulated glass units having at least two panes of glass with an air space in between and a spacer near the periphery of the insulated glass unit. More specifically, the invention relates to application of the secondary seal to insulated glass units.
Insulated glass units are commonly used in windows and doors because of their superior resistance to heat flow as compared to single glazed windows or doors. Their superior insulating qualities make insulated glass units useable for almost any application in which a structure is temperature controlled inside as compared to the outside.
Insulated glass units generally include at least two panes of glass having identical shapes. The two panes of glass are separated by an air gap and held together by a spacer which follows the exterior perimeter of the two panes of glass and is inset somewhat from the peripheral edges of the two panes of glass. The spacer is adhesively bonded to the two panes of glass and creates the, so called, primary seal between the two panes of glass. The space thus formed between the two panes of glass may be filled with ambient air or other gases to create a dead space which provides the insulating qualities of insulated glass units.
As discussed above, the spacer in an insulated glass unit is inset from the peripheral edges of the glass panes leading to a trough shaped space bounded on two sides by the glass panes and on one side by the spacer. In the manufacturing of insulating glass units, this space is filled with an adhesive sealant which forms the, so called, secondary seal of the insulated glass unit. The secondary seal may be applied using a variety of different adhesive sealants. These include time setting sealants, such as silicones or butyl rubber sealants. Sometimes two part sealants utilizing a resin and a catalyst to polymerize the resin are utilized. More commonly in modern manufacturing, hot melt adhesive sealants are used. Hot melt adhesive sealants are general applied in a liquid state at a temperature of approximately 350° F. and harden upon cooling to ambient temperature.
In high volume manufacturing facilities, the secondary seal is commonly applied by fully automated equipment in which a computer controlled robotic sealant applying head is moved around the peripheral edges of the insulated glass unit under computer control and applies the sealant to the edge or edges of the insulated glass unit. Fully automated secondary edge sealing equipment of this sort can apply to the secondary seal to very large numbers of insulating glass units in a production run. Typically, the insulated glass units in these circumstances are produced in large runs of identical units.
Fully automated edge sealing equipment of this type requires highly precise computer numerically controlled programming in order to apply a consistent edge seal. Because of this and the requirement that the equipment be programmable to handle many different sizes and shapes of insulated glass units cause this sort of equipment to be quite expensive to purchase and maintain.
There also exist in the window and door manufacturing industry smaller manufacturing facilities at which short runs of custom made windows or doors are manufactured in small quantities or even in single unique units. In these facilities, secondary edge sealing is generally accomplished by hand held equipment in which an operator applies the secondary sealant with a device similar to a caulking gun. These hand held dispensing units may have power to assist to dispensing the sealant and some control over the dispensing rate that is automated. It is not possible to make as consistent quality edge seals with these devices as fully automated equipment and the operator must have considerable practice and skill in order to achieve a good result.
Accordingly, there is still room for improvement in the area of secondary edge sealing of insulated glass units.
The fixed head insulated glass unit edge sealant according to an embodiment of the invention, generally includes a table having a fence, a fixed head sealant dispenser, a controller and a sealant supply.
The table generally includes a surface that allows minimally restricted multi-directional movement of an insulated glass unit (IGU) when the IGU is laying horizontally on the table surface. According to one example embodiment of the invention, the table includes multi-directional rollers on the surface thereof. In another embodiment of the invention, an air table may be utilized. In a further embodiment of the invention, ball bearing rollers may be utilized as the support surface of the table. Yet another embodiment of the invention, casters may be utilized.
One embodiment of the invention includes an operator space located within the table and a moveable IGU support that is moveable within the operator's space to adjust for the different sizes of insulated glass units that are being sealed.
According to one example embodiment of the invention, a fence is located at one edge of the table. The fence serves to provide a linear barrier along which insulated glass units that are to be edge sealed can be moved. The fence can include for example, a vertical barrier having a low friction surface on the side facing the table. The low friction surface may include but is not limited to nylon, Teflon or plastic laminates. In another example embodiment of the invention, the fence includes vertically oriented rollers against which the IGU's can be moved. The fence is aligned with the fixed head sealant dispenser.
The fixed head sealant dispenser in accordance with an example embodiment of the invention, generally includes a high volume metering pump, a dispensing nozzle, a depth sensor, a dam, proximity sensors and a device for sensing movement parallel to the fence. One example embodiment of the invention includes a dual dispensing nozzle for edge sealing of triple glazed insulated glass units. The dual dispensing nozzle has dual skis that share an interdigitated common edge that is adapted to ride along the edge of the center pane of glass in a triple glazed insulated glass unit.
The fixed head sealant dispenser may also include proximity sensors, for example, to sense the presence of an insulated glass unit to cause lowering of the dispensing head and extension of the dam. A second proximity sensor may be utilized to actuate an auto-stop of the dispensing pump when the end of a side of the insulated glass unit is reached. An example embodiment of the present invention may also include a heated nozzle garage, a laser indicator aligned with the nozzle orifice or a mastic regulator.
The high volume metering pump in accordance with one aspect of the invention may have a volume capacity of approximately 15 gallons per minute which far exceeds the required pumping capacity for edge sealing. The use of this high volume pump permits the pump to operate at 30-50 revolutions per minute instead of approximately 200 revolutions per minute. This arrangement greatly increases the useful life of the high volume metering pump.
An example dispensing nozzle in accordance with the invention generally includes a dispensing orifice and a ski assembly which permits the dispensing nozzle to ride along the edge of an insulated glass unit. In one example embodiment, the dispensing nozzle has a quick change feature which utilizes a cam latch to apply pressure to the nozzle to seat it into its receptacle. The cam latch is useful to prevent dislodging of the nozzle under the high pressure utilized when applying this to sealants. In accordance with example embodiments of the invention, the cam latch may have a front or rear location for convenience of the operator when the nozzle is to be changed.
The dispensing nozzle orifice may be generally slot or dumbbell shaped and oriented perpendicular to the long axis of the edge sealing cavity to be sealed.
The ski of the dispensing nozzle, in an example embodiment of the invention, includes a spring or other biasing member to press the ski outwardly slightly away from the dispensing orifice. In an example embodiment of the invention, the surface of the ski that contacts the insulated glass unit is mirror polished and has a shallow radius of curvature. The inventor of the present invention has discovered that a two to four inch radius of curvature is useful for edge sealing insulated glass units of various commonly encountered thicknesses.
One example embodiment of the invention includes a dual dispensing nozzle for use with triple glazed insulated glass units. The dual dispensing nozzle for triple glazing includes two skis as described above. The two skis have a specially designed interdigitated interlocking structure so that the two skis appropriately ride along the edge of the glass panes of a triple glazed insulated glass unit.
The depth sensor, in accordance with an example embodiment of the invention, senses the depth or inset of the spacer along the perimeter of an insulated glass unit and judges the distance from the edge of the glass panes to the location of the spacer. The depth sensor in accordance with an example embodiment may include for example a mechanical finger sensor or an ultrasound sensor. Other types of depth sensors or distance sensors known to those of ordinary skill in the art may be utilized as well. Data from the depth sensor is utilized to adjust the volume of sealant dispensed from the dispensing nozzle to edge seal an insulated glass unit. The depth sensor is valuable because spacers are not always applied exactly parallel to the edge of the insulated glass unit panes.
The fixed head sealant dispenser may also include a perpendicular moveable dam. The dam, when extended, is generally perpendicular to the edge of the insulated glass unit and to the ski or skis of the dispensing nozzle. The dam functions as stop for halting movement of the insulated glass unit at a desired location for starting edge sealing. The dam also serves to confine an initial prestart application of adhesive sealant to seal the corner area of an insulated glass unit at the beginning of an edge sealing application. The dam may also be heated in one embodiment of the invention.
The device for sensing movement parallel to the fence may include an encoder that senses manual linear movement of the IGU parallel to the fence. The encoder may be embodied in the form of a wheel having a frictional rim which rides against the insulated glass unit when it is moved. The encoder provides speed of movement or relative movement information to the controller to calculate the dispensing rate of the dispensed sealant. In another embodiment of the invention, the device for sensing movement parallel to the fence may include pinch rollers which may be powered to assist movement or may be passive in order to sense movement if the insulated glass unit is moved manually. The encoder or pinch rollers, in particular, the pinch rollers may be utilized to provide a prestart of the pump prior to motion of the insulated glass unit relative to the fixed dispensing head, for example, in the case of a two part sealant which is passed through a static mixing tube prior to being dispensed. In this case, the pump is started prior to the beginning of movement of the insulated glass unit to provide time for the sealant to overcome the friction of the static mixing tube.
Another example embodiment of the invention may include a heated nozzle garage. The heated nozzle garage may include an enclosure or a block of metal having significant thermal mass. The dispensing nozzle is retracted into or against the heated nozzle garage between dispensing operations to heat the dispensing nozzle at a temperature that will maintain the sealant in a fluid state when using a hot melt sealant. The heated nozzle garage need not be an enclosure, but instead can be block of metal against which the nozzle is pressed so that thermal energy from the heated block of metal is transferred by conduction to the dispensing nozzle to maintain fluidility of the hot metal sealant.
Another embodiment of the invention includes a laser indicator aligned with the nozzle orifice. The laser indicator can be used by an operator to assist in deciding when to stop the flow of sealant at the end of an insulated glass unit sealing when the full perimeter of the insulated glass unit has been transited.
Another embodiment of the invention includes a mastic regulator. The mastic regulator serves to lengthen pump life.
The controller in accordance with the invention includes a human machine interface (HMI). The human machine interface includes a computer monitor, optionally of a touch screen variety, which includes operator controls. For example, the HMI is used to adjust the device for the known width of the spacer in the insulated glass unit, thereby providing one piece of information toward calculating the amount of sealant to be applied. The human machine interface also includes a foot switch which is actuated by the operator to operate the machine. The human machine interface also includes a processor unit which may be based on a personal computer or other dedicated processor. The processor unit can be programmed with the information to operate the fixed head insulated glass unit edge sealer.
The sealant supply is supplied to the unit under pressure from a supply of sealant, often a heated 55 gallon drum with a pressure pump. The sealant supply can be any source of supply of sealant whether hot melt sealant, two part sealant or time setting sealant that provides significant sealant to supply the pump metering device in order to allow the edge sealing of insulated glass units.
Referring to
Table 22 generally includes ground engaging legs 32, IGU support structures 34 and overhead lights 36. Table 22 is sized to accommodate the largest insulated glass unit that it is expected to be used to edge seal. Table 22 according to an example embodiment of the invention is generally U-shaped when viewed from above and defines operator space 38 within table 22. IGU support structures 34 are structured to permit minimally restricted multi-directional movement of a generally planar object such as an insulated glass unit that is placed horizontally upon table 22.
In one example embodiment, table 22 includes a plurality of multi-directional rollers 40 thereon. Multi-directional rollers may be supported in rows by a plurality of U-profile channels 42. Multi-directional rollers 40 may include simplex rollers or duplex rollers. One acceptable type of multi-directional roller 40 that can be used in accordance with the invention is described in U.S. Pat. No. 5,404,984 to Hagman. Such rollers can be purchased from ErgoTech Inc. located at 11 Old New Town Road, Commerce Park, Danbury, Conn. 06810.
Other IGU support structures 34 that may be utilized include an air table (not shown), ball bearing rollers (not shown) or casters (not shown).
Operator space 38 is made of appropriate dimensions to permit an operator to approach closely enough to fixed head sealant dispenser 26 to manually manipulate small size insulated glass units that may be edge sealed by operation of the invention.
Operator space 38 may include moveable IGU support 44. Moveable IGU support 44 is slidably adjustable within operator space 38 in a direction that permits moveable IGU support 44 to be moved closer to or further from fixed head sealant dispenser 26. Moveable IGU support 44 may include one or more U-profile channels 42 including multi-directional rollers 44 or other IGU support structures 34 described above. U-profile channels 42 of moveable IGU support 44 may be oriented generally parallel to fence 24. Moveable IGU support 44 may also include foot pedal support 46 moveable therewith.
According to an embodiment of the invention, U-profile channels 42 are arranged generally parallel to fence 24 and parallel to the direction in which insulated glass units to be sealed are to be moved in the sealing process.
Fence 24 according to the embodiment depicted in
Fence 24 is located along an edge of table 22 that is near to fixed head sealant dispenser 26.
Referring to
High volume metering pump 50 in an example embodiment, is a positive displacement gear metering pump. Other types of metering pumps may be used as well. In an example embodiment, high volume metering pump 50 is selected to have a capacity of four to six times greater than the maximum expected flow rate for fixed edge IGU edge sealer 20. In this way high volume metering pump 50 can operate at 15 to 25 percent of its maximum capacity, which increases pump life.
For example, in one embodiment of the invention, a fifteen gallon per minute pump is utilized so that it operates at thirty to fifty rpm instead of its maximum capacity of approximately two hundred rpm. High volume metering pump 50 is coupled to sealant supply 30 in which sealant is supplied under pressure to high volume metering pump 50. High volume metering pump 50 is also coupled to dispensing nozzle 52. Electrically or pneumatically controlled dispensing valves 61 may be interposed between high volume metering pump 50 and dispensing nozzle 52.
In one example embodiment, dispensing nozzle 52 generally includes body 64, which defines dispensing orifice 66, ski 68 and quick change coupling 70. Dispensing nozzle 52 will be further described below.
Referring to
Referring to
Proximity sensors 58 are adapted to sense the presence of an insulated glass unit on table 22 near to fixed head sealant dispenser 26. One of proximity sensors 58 is located approximately at the location of dispensing nozzle 52. Another of proximity sensors 58 may be located significantly prior to dispensing nozzle 52 along the path at which an insulated glass unit is moved pass dispensing nozzle 52.
Referring again to
In another example embodiment of the invention, movement encoder 60 may include pinch rollers (not shown) that contact the top and bottom of an insulated glass unit moved along fence 24. The pinch rollers (not shown) may be passive if the insulated glass unit is moved manually or may be active and powered to assist in movement of the insulated glass unit.
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
A laser indicator aligned with nozzle orifice 124 may be utilized with the invention as well. Laser indicator (not shown) assists an operator with judging the location of nozzle orifice 124 relative to the insulated glass unit being edge sealed.
Fixed head sealant dispenser 26 may also include a mastic regulator (not shown) which controls sealant pressure and assists in lengthening pump life.
Controller 28 generally includes human machine interface (HMI) 126 and processor unit 128. Human machine interface 126 generally includes monitor 130 and foot pedal switch 132. Monitor 130 may be a touch screen monitor in order to actuate various controls. Processor unit 128 is operably coupled to and adapted to receive input from monitor 130 and foot pedal switch 132 as well as depth sensor 54, proximity sensors 58 and movement encoder 60. Processor unit 128 is also adapted to receive input from depth sensor 54 and to actuate the dispensing of sealant at a controlled volume depending upon the inputs from depth sensor 54, movement encoder 60 and human machine interface 126.
Sealant supply 30 is capable of supplying sealant under pressure and often includes a pump adapted to be coupled to a 55 gallon drum or other container of sealant. Sealant supply 30 is known in the art and will not be further described here.
In operation, an operator places an insulated glass unit that it is desired to edge seal on table 22. The IGU rests on IGU support structures 34, such as multi directional rollers 40. The operator moves the insulated glass unit until a first edge of the insulated glass unit makes contact with fence 24. The insulated glass unit is then slid along and in contact with fence 24 until it comes into the proximity of proximity sensors 58. Proximity sensors 58 sense the presence of the insulated glass unit and send a signal to controller 28 regarding the presence of insulated glass unit. Controller 28 then commands the extension of dam 56 and the positioning of fixed head sealant dispenser 26, proximate fence 24 and the insulated glass unit to be sealed. The operator then manually moves the insulated glass unit until it comes into contact with dam 56 and ski 68.
The operator then steps on foot pedal switch 132 which sends a signal to controller 28. In response to the signal, controller 28 actuates high volume metering pump 50 and depth sensor 54. Depth sensor 54 senses the depth at which the spacer of the insulated glass unit is recessed from the edge of the insulated glass unit and sends a signal to controller 28. Controller 28 then activates high volume metering pump 50 to make a prestart dispense of sealant. The prestart dispense of sealant fills the edge seal area of the insulated glass unit in the vicinity of the corner of the insulated glass unit where the insulated glass unit makes contact with dam 56 and IGU contact surface 82. Dam 56 and IGU contact surface 82 guide the sealant to fill the corner area of the insulated glass unit. Following this dispensing, controller 28 actuates retraction of dam 56.
The operator then manually moves the insulated glass unit, in this example embodiment, while maintaining contact with fence 24 and IGU support structures 34. Ski 68 remains in contact with the edge of the insulated glass unit. Because ski 68 is moveable and spring biased, it makes contact with the glass panes of the insulated glass unit and keeps sealant within the cavity to be filled. As the insulated glass unit moves along fence 24 and in contact with ski 68, as the insulated glass unit movement continues to move, depth sensor 54 continuously monitors the depth of the cavity being filled and provides information to controller 28 so that the quantity of sealant dispensed is appropriate to fill the cavity properly.
Prior to beginning the edge sealing process, the operator inputs data through human machine interface 126 to controller 28 as to the width of the insulated glass unit cavity between the panes of glass to be filled. The operator continues to move the insulated glass unit until the first edge of insulated glass unit approaches dispensing orifice 66. The operator may be assisted in judging this by the laser indicator device (not shown). The operator then can remove his foot from foot pedal switch 132 to deactivate pressure sensor 54 and high volume metering pump 50. At this point, controller 28 orders retraction of dispensing nozzle 52 and deactivation of depth sensor 54.
The operator can then move the insulated glass unit away from fence 24 on table 22 and rotate the insulated glass unit approximately ninety degrees or whatever rotation is appropriate to bring the next side of the IGU into contact with fence 24. The operator then returns the second edge of the insulated glass unit to contact with fence 24 and repeats the edge sealing procedure above for each side of the insulated glass unit.
The fixed head IGU edge sealer 20 of the present invention also is adapted to provide edge sealing of curved edges of IGU units which is accomplished in a similar fashion except that the operator keeps the curved edge of the IGU in contact with the dispensing nozzle 52 and depth sensor 54 while rotating the IGU about the center of the curvature of the curved side being sealed rather than moving the IGU parallel to fence 24.
Triple glazed IGU's can be edge sealed with single nozzle sealant dispenser 62 by edge sealing one of the two edge spaces first and then sealing the second of the edge spaces in a subsequent procedure.
Alternately, triple glazed insulated glass units can be edge sealed using dual fixed head sealant dispenser 120. The procedure to be followed is essentially identical to that above except for the fact that the two separate depth sensors independently sense the depth of the two separate edge seal cavities to be filled. Thus, the sealant dispensing is adjusted by controller 28 so that the proper volume of sealant is dispensed to edge seal each of the cavities simultaneously.
When edge sealing triple glazed IGU's, the upper edge of first ski 92 rides along the upper pane of glass, the lower edge of second ski 94 rides along the lower pane of glass, the central pane of glass abuts the juncture between first ski 92 and second ski 94. The interdigitated configuration of tab slots 102, downwardly extending tabs 100, upwardly extending tabs 104 and tab insets 106 permits dual ski assembly 90 to ride along the edges of all three insulated glass unit panes to properly confined the sealant to the appropriate cavities.
In an alternative embodiment of the invention, pinch rollers (not shown) may grip the insulated glass unit and also operate as movement encoder 60. Pinch rollers (not shown) may be motorized to provide a power assist to an operator moving an insulated glass unit for edge sealing. This arrangement may be helpful particularly in the use of two part sealants. Two part sealants include two components which are dispensed through a static mixing tube prior to being applied to the insulated glass unit. The static mixing tube provides considerable resistance to flow of the two part sealant and there is lag between the beginning of operation of the pump and the beginning of the flow of sealant at dispensing nozzle 52. Further, when high volume metering pump 50 is deactivated, there is continuing flow of sealant through the static mixing tube for a period of time thereafter. According to this embodiment of the invention, controller 28 is programmed to allow for this lag of dispensing and excess dispensing at the end.
Hot melt sealants are used more and more in modern manufacturing of insulated glass units. Heated nozzle garage 122 assist in the use of hot melt sealants by providing a source of additional heat to dispensing nozzle 52 when sealant is not flowing. When sealant is flowing, the heat of the already heated sealants keeps dispensing nozzle 52 at an appropriate temperature. In between insulated glass sealing procedures dispensing nozzle 52 tends to cool and become clogged with hot melt sealants. The use of heated nozzle garage 122 prevents this by providing an additional source of heat to dispensing nozzle 52. It is also possible to provide heating elements in contact with or inside of dispensing nozzle 52. This however increases the complexity of dispensing nozzle 52.
When an operator is edge sealing small insulated glass units, the operator may stand in operator space 38 and move movable IGU support 44 to position close to fixed head sealant dispenser 26. When larger insulated glass units are edge sealed, the operator may move movable IGU support 44 out farther away from fixed head sealant dispenser 26 to provide additional support for the insulated glass unit as it crosses operator space 38.
Overhead lights 36 provide additional illumination for insulated glass unit and its sealing operations.
Quick change coupling 70 facilitates the changing of dispensing nozzle 52. When it is desired to change dispensing nozzle 52, an operator may disengage cam lock 114, this releases force from lever 116 and allows lever 116 to pivot about fulcrum 118. Dispensing nozzle 52 may then be removed from its position. Boss 110 and bore 112 of dispensing nozzle 52 are coupled to complementary structures 113 in order to ascertain proper alignment of dispensing nozzle 52. Cam lock 114 then is actuated causing lever 116 to pivot about fulcrum 118 and to press dispensing nozzle 52 against complementary structures 113 to seal it in place.
Foot pedal switch 132 may be locate on foot pedal support 46, thus foot pedal support 46 and foot pedal switch 132 travel with movable IGU support 44 as it moves so that an operator may always reach foot pedal switch 132 regardless of the size of insulated glass unit being edge sealed.
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.
