Abstract:
A portable defogging device for defogging multi-paned windows comprising an open loop source of low moisture gas and a flexible conduit for introducing the gas into the enclosed space between the window panes. A regulator is used to introduce the fixed rate of flow of gas through the flexible conduit and into the enclosed space so as to remove the pre-existing or previous condensation in the enclosed space. In a double-paned aircraft window, the low moisture gas is introduced through a pressure equalization hole in the window. A method of defogging a multi-paned window comprising passing a low moisture gas through a flexible conduit and into an enclosed space between at least two window panes. The discharge of gas is regulated to a constant flow so as to remove moisture from the enclosed space, wherein the defogging device is deactivated and removed from the window to complete the defogging cycle.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority based on provisional U.S. patent application Ser. No. 60/157,547 filed on Oct. 4, 1999. 
    
    
     FIELD OF INVENTION 
     The present invention relates to the removal of fog or moisture in multi-paned windows. In particular, the present invention provides for the easy removal of moisture trapped in double-pane aircraft windows. 
     BACKGROUND OF INVENTION 
     The fuselage of aircrafts typically contain double-paned windows wherein two window panes are spaced apart from one another. A window seal surrounds the outer perimeter of the window panes thereby enclosing the space between the window panes. The outer surface of the inner window pane is exposed to the cabin area and the outer surface of the outer window pane is subjected to the environment outside of the aircraft. In order to achieve a pressure equalization in the window during flight, a ventilation hole is provided at or near the bottom of the inner window pane. This ventilation hole allows the exchange of air to take place between the pressurized cabin interior and the enclosed window space. For example, if the pressure in the cabin is greater than the pressure in the enclosed window space, then air will flow from the cabin into the enclosed space and achieve a pressure equalization. 
     The outer window pane may be subjected to temperatures as low as −30° C. during flight. As a result, water vapor present in the cabin air that flows into the enclosed window space will condense on the inner surface of the outer window pane. The outer window pane will become fogged by condensation providing little or no visibility for the aircraft passenger. The condensation on the window pane may even form into a layer of frost or ice due to the low external temperatures during the flight. As the aircraft then descends into warmer air strata, the frost or ice layer within the enclosed window space will melt, forming fog or water droplets on the window panes, and in the extreme situation even causing the accumulation or puddling of condensed water at the bottom of the enclosed space. Greater condensation will occur as the relative humidity of the interior cabin air increases, which is dependent upon the flight conditions of the aircraft. For example, the relative humidity may be affected by the number of passengers in the aircraft and the location and climatic conditions of the flight. 
     Currently, in order to remove moisture that accumulates in the enclosed window space, it is necessary to disassemble the window unit and clean and/or replace the window panes. This is typically a very costly and time consuming procedure. 
     SUMMARY OF INVENTION 
     The present invention solves the above-described problem by providing a defog device that easily defogs multi-paned windows comprising a source of low moisture gas, a flexible conduit for introducing the low moisture gas into the enclosed space between the window panes, and a regulator to control the flow of gas through the flexible conduit and into the enclosed space. The low moisture gas is preferably nitrogen. The flow of low moisture gas causes any condensation in the enclosed space to evaporate and be carried out of the enclosed space with the gas. This device is especially useful for defogging double-paned windows of aircrafts, but may be used to remove condensation from any multi-paned window such as those found in residential, commercial and industrial structures. 
     More particularly, the defog device of the present invention comprises a flexible conduit which is capable of introducing low moisture gas into the enclosed window space through a ventilation hole in one of the window panes. The ventilation hole may be a drilled hole in one of the panes. The defog device may further comprise an injection tube connected to the flexible conduit for introducing low moisture gas into the enclosed space. The injection tube is also capable of introducing the gas into the enclosed window space through a ventilation hole in one of the window panes. 
     Still more particularly, the defog device of the present invention comprises a flexible conduit that is adapted to introduce low moisture gas into more than one multi-paned window, wherein the flexible conduit is capable of being connected to the windows in series and introducing low moisture gas into the enclosed space of each window. An attachment means and a hanging means may be used to hold the flexible conduit in place at each window. 
     Alternatively, the defog device of the present invention may further comprise a manifold connected to the regulated low moisture gas. At least one additional flexible conduit is connected to the manifold, wherein the additional flexible conduit is adapted to introduce low moisture gas into more than one window. Each window comprises at least two window panes and an enclosed space between the window panes. The additional flexible conduit is capable of being connected to the windows in series and introducing nitrogen gas into the enclosed space of each window. 
     The present invention also relates to a method of defogging a multi-paned window comprising passing a low moisture gas through a flexible conduit and into an enclosed space between at least two window panes. The flow of gas through the flexible conduit is regulated so as to remove moisture from the enclosed space. The low moisture gas may be introduced into the enclosed space through a ventilation hole in one of the window panes. Preferably, the low moisture gas is nitrogen. 
     An injection tube may be connected to the flexible conduit, whereby the injection tube is inserted into the enclosed window space and low moisture gas is introduced into the enclosed space through the injection tube. 
     More particularly, the flexible conduit is adapted to introduce low moisture gas into more than one window, wherein each window comprises at least two window panes and an enclosed space between the window panes. The step of introducing low moisture gas further comprises connecting the flexible conduit to the windows in series and introducing low moisture gas into the enclosed space of each window. The flexible conduit may be attached to one of the window panes of each window with an attachment means and a hanging means. 
     A plurality of injection tubes may be connected to the flexible conduit, whereby the method further comprises inserting each injection tube into an enclosed window space and introducing low moisture gas through each injection tube into an enclosed space. 
     The method of the present invention may further comprise connecting a manifold to the regulated low moisture gas and passing the low moisture gas through the manifold into at least one additional flexible conduit. The additional flexible conduit is adapted to introduce low moisture gas into more than one window, wherein each window comprises at least two window panes and an enclosed space between the window panes. The additional flexible conduit is connected to the windows in series and introduces low moisture gas into the enclosed space of each window. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevation view of a defog device made in accordance with an embodiment of this invention. 
     FIG. 2 is an elevation view of a defog device made in accordance with an alternative embodiment of this invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, shown is a defog device  10  for a multi-paned window which includes a flexible conduit  12  for introducing low moisture gas into an enclosed space between at least two window panes  14  and  15 , a source of low moisture gas  16 , and a regulator  17  for controlling the flow of low moisture gas through the flexible conduit. 
     The multi-paned window illustrated in FIGS. 1 and 2 comprises an inner pane  14  and an outer pane  15 . A seal  19  surrounds the perimeter of the inner pane  14  and outer pane  15  forming an enclosed space therebetween. In an aircraft, for example, the inner pane  14  is exposed to atmosphere inside of the aircraft cabin while the outer pane  15  is subjected to the cold temperatures of the environment outside of the aircraft. The inner pane  14  typically contains a ventilation hole  21  located near the bottom of the pane. The ventilation hole  21  provides for the exchange of air between the cabin interior and the enclosed window space allowing the pressure to be equalized between these two areas. This is particularly important during the climb and descent phases of a flight. 
     However, pressurized cabin air containing water vapor may pass through the ventilation hole  21  as well as through gaps in the enclosed space. Since the outer pane  15  is at lower temperature than the cabin air passing into the enclosed window space, vapor in the air will condense on the inner surface of the outer pane  15 . As a result, the outer pane  15  becomes fogged with condensation. 
     The defog device of the present invention introduces a low moisture gas into the enclosed window space through a flexible conduit  12 . The flow of low moisture gas into the enclosed window space causes any condensation in the enclosed space to evaporate and be carried out of the space with the gas. 
     The flexible conduit  12  may be constructed from a variety of materials including, but not limited to rubber and plastic such as polyethylene, polypropylene and polyvinylchloride. Preferably, the flexible conduit  12  is made of plastic. It is also preferred that the flexible conduit  12  be capable of introducing the low moisture gas through the ventilation hole  21  in the inner pane  14 . The ventilation hole  21  may be a drilled hole in one of the window panes  14  and  15 . If a ventilation hole  21  is not present in one of the window panes, the low moisture gas may be introduced through any opening large enough to allow an adequate flow of low moisture gas into the enclosed window space to remove the condensation. 
     Alternatively, an injection tube  22  may be connected to the flexible conduit  12  for introducing low moisture gas into the enclosed space. The injection tube  22  may be connected to the flexible conduit  12 , for example, through the use of a T-coupling or similar type fitting. It is also preferable that the injection tube  22  be capable of introducing low moisture gas through the ventilation hole  21 . However, if a ventilation hole  21  is not present in one of the window panes, the low moisture gas may be introduced through any other opening in the enclosed window space. 
     The injection tube  22  may be flexible or rigid and may be constructed of any material, including, but not limited to rubber, plastic, flexible catheter tubing and metal. For instance, the injection tube  22  may be a catheter, or a needle such as a curved hypodermic needle. 
     Any non-oxidizing gas having a low water vapor content may serve as the source of low moisture gas  16  in the present invention. Gases which may be used include, but are not limited to air, nitrogen, argon, helium and carbon dioxide. 
     A regulator  17  controls the flow of low moisture gas through the flexible conduit  12  and into the enclosed window space so that the flow of gas is adequate to remove moisture from the enclosed space. The regulator of the present invention may be any regulator known to those having ordinary skill in the art. Preferably, the regulator  17  maintains the pressure of the low moisture gas in the flexible conduit  12  between about 2 psi to about 25 psi. 
     As FIG. 1 indicates, the flexible conduit  12  may be adapted to introduce low moisture gas into more than one multi-paned window. The flexible conduit  12  may be connected to the windows in series and include as many windows as necessary to complete the defogging operation. The low moisture gas is introduced through the enclosed space between the window panes  14  and  15  in each window. 
     A plurality of injection tubes  22  may be connected to the flexible conduit  12  wherein the low moisture gas is introduced into the enclosed space of each window through a respective injection tube. 
     FIG. 2 illustrates another embodiment of the present invention wherein a manifold system is used to introduce low moisture gas into a plurality of multi-paned windows. In this embodiment, the defog device comprises a manifold  24  connected to the regulated low moisture gas, and at least one additional flexible conduit  25  connected to the manifold. The additional flexible conduit  25  is adapted to introduce low moisture gas into the enclosed space of more than one window. The additional flexible conduit  25  is capable of being connected to the windows in series and introducing low moisture gas into the enclosed space of each window. The manifold system is useful for maintaining the pressure in the flexible conduits  12  and  25  between 2 psi and 25 psi when there are a large number of windows involved in the defogging process. The manifold system is also helpful, for instance, when there are windows to be defogged in various locations in a structure. 
     The additional flexible conduit  25  may be constructed of the same materials as the flexible conduit  12 . 
     Whenever low moisture gas is being introduced into the enclosed space of more than one multi-paned window, the defog device of the present invention may further comprise a plurality of attachment means  26  and a plurality of hanging means  27 . Each attachment means  25  is capable of being attached to one of the window panes of each window and is preferably attached to the inner window pane  14 . The attachment means may be any device capable of being attached to the window pane, including, but not limited to a suction cup, glue and tape. It is preferable that the attachment means is a suction cup. Each hanging means  27  is connected to an attachment means  26  and performs the function of holding the flexible conduits  12  and  15  in place next to each window. Examples of appropriate hanging means include, but are not limited to hooks, wire or plastic attachments. The shape and material of construction for the hanging means  27  is not important so long as they are constructed to adequately hold the flexible conduits  12  and  15  in place. 
     The attachment means  26  and hanging means  27  may be one unit or they may be two separate pieces that are connected together. The flexible conduits  12  and  25  may be held in place directly by the attachment means  26  without the hanging means  27 . For instance, the attachment means  26  may comprise an adhesive surface for attachment to the flexible conduits  12  and  25 . 
     The present invention also relates to a method of defogging a multi-paned window comprising passing a low moisture gas through a flexible conduit and into an enclosed space between at least two window panes. The flow of gas through the flexible conduit  12  is regulated so as to remove moisture from the enclosed space. The low moisture gas may be introduced into the enclosed space through a ventilation hole  21  in one of the window panes  14  and  15 . The ventilation hole  21  may be a drilled hole. If a ventilation hole  21  is not present, the method may further comprise drilling a hole in one of the window panes  14  and  15  to permit access to the enclosed window space. 
     An injection tube  22  may be connected to the flexible conduit  12 , whereby the injection tube is inserted into the enclosed window space and low moisture gas is introduced into the enclosed space through the injection tube. 
     The flexible conduit  12  may be adapted to introduce low moisture gas into more than one window, wherein each window comprises at least two window panes  14  and  15  and an enclosed space between the window panes. The step of introducing low moisture gas further comprises connecting the flexible conduit  12  to the windows in series and introducing low moisture gas into the enclosed space of each window. The flexible conduit  12  may be attached to one of the window panes  14  and  15  of each window with an attachment means  25  and/or hanging means  26 . 
     A plurality of injection tubes  22  may be connected to the flexible conduit  12 , whereby the method further comprises inserting each injection tube into an enclosed space and introducing low moisture gas through each injection tube into an enclosed space. 
     The method of the present invention also may further comprise connecting a manifold  24  to the regulated low moisture gas and passing the low moisture gas into at least one additional flexible conduit  25 . The additional flexible conduit  25  is connected in series to more than one window and introduces low moisture gas into the enclosed space of each window. The additional flexible conduit  25  may be attached to one of the window panes  14  and  15  of each window with an attachment means  26  and/or hanging means  27 . 
     It should be understood that the foregoing relates to particular embodiment of the present invention, and that numerous changes may be made therein without departing from the scope of the invention as defined by the following claims.