Abstract:
The present invention comprises a cover for wintertime protection of an outdoor air conditioning unit (OACU). The cover provides a rigid top piece to provide protection from falling objects and a semi-permeable side skirt to reduce dirt and debris entering the unit while still allowing moisture to evaporate from the unit and means to attach the cover to the unit. The cover may also be equipped with foam padding for the underside of the rigid top piece which provides for abrasion resistance for the OACU and will also provide for tilting of the cover when an unevenly distributed weight load is applied to the upper surface of the cover; the tilting facilitates runoff of ice and snow from the unit reducing the weight load bearing on the OACU.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     Priority for this patent application with the exception of claim  11  is based upon provisional patent application 61/337,354 (filed on Feb. 3, 2010). The disclosure of this U.S. patent application is hereby incorporated by reference into this specification. 
    
    
     BACKGROUND OF THE INVENTION 
     Central air conditioners are used to maintain indoor ambient air temperatures at comfortable ranges during hot weather. In the northern United States, the air conditioning season will typically run through the summer months; in the southern United States, the air conditioning season will typically run from mid-spring through mid-autumn. Central air conditioners typically consist of an indoor air conditioning unit, an outdoor air conditioning unit, and plumbing, electrical, and ductwork between the units and throughout the building to be cooled. 
     Outdoor air-conditioning units (OACU&#39;s) typically include a compressor, a condenser, a grill, various piping and valves, and a fan all contained within a metal housing and are powered by electrical wiring routed from the building they serve. The purpose of an indoor air-conditioning unit is to transfer the heat from a building or structure to refrigerant in the air-conditioning system piping which vaporizes to a gaseous state thereby lowering the temperature within the building, and then transmits this refrigerant gas via piping to the outdoor air-conditioning unit where the compressor converts the gas back to a liquid in the condenser, thereby generating heat that is transferred to ambient environment outside of the building or structure with the fan. The outdoor air-conditioning units are frequently located close to the building they serve so that the distance that the transfer piping requiring thermal insulation must traverse is minimized. They are often located in a position where the eaves of the building and trees or shrubbery will shade the unit from direct solar radiation. 
     During the winter months when air conditioning is not utilized, the outdoor air-conditioning unit is susceptible to damage from snow, ice, and other hard objects falling from the eaves and trees. Since the fan motor of an outdoor unit is frequently mounted to the underside of the top panel of the unit, the fan motor is particularly susceptible to damage. Furthermore, the top panel is usually formed with fins or a grille which are also easily damaged by falling objects. Therefore, it is desirable for an air conditioner cover to be capable of protecting against such damage from wind-driven precipitation and hard, falling objects, yet be easily installed or removed and stowable during the warm seasons. It is important that through ventilation can enter the sides of the unit to dry out moisture inside the unit which may lead to condensation and ultimately to corrosion. If the cover is supplied as an accessory by the air conditioning manufacturer, a displayed trademark or name may be of value. 
     People oftentimes use a simple piece of plywood with a cinderblock placed on top of it to protect the OACU during the off-season. There are several limitations associated with this including the potential to scratch and dent the upper surface of the OACU and the fan grille and the aesthetics of the plywood and cinderblock. 
     Covers to protect the OACU have been available since the 1960&#39;s, but those have primarily been simple canvas covers designed to totally or nearly totally enclose the OACU. However, these devices do not address the perils discussed earlier, that of falling objects such as ice and tree limbs, or rain and moisture trapped inside the covered OACU. Aubuchon provided a ventilating protective cover for top-discharge air conditioners (U.S. Pat. No. 5,097,678) designed to provide corrosion protection to the upper portion of the OACU. Aubuchon&#39;s cover used an impervious skirt that covered only the upper portion of the OACU and only provided protection to that portion of the OACU. Because the skirt used by Aubuchon was impervious to moisture, use of the skirt to cover more than 50 percent of the OACU would result in corrosion of the underlying OACU as trapped moisture would be unable to escape the unit. Nelson provided an air conditioner cover (U.S. Pat. No. 5,307,849) with a panel and a flexible shroud to protect the air conditioner cover. This cover provided protection against falling objects but provided no protection from moisture to be trapped inside the covered OACU which could lead to corrosion of the OACU. The present invention addresses all these limitations and is described herewith. 
     Additionally, a fully enclosed OACU is an inviting home for rodents, which may lead to additional damage to the unit. The present invention does not fully enclose the OACU and does not present an attractive home for rodents. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention comprises a cover for wintertime protection of an outdoor air conditioning unit (OACU). The cover provides a rigid top piece to provide protection from falling objects and a semi-permeable side skirt to reduce dirt and debris entering the unit while still allowing moisture to evaporate from the unit and means to attach the cover to the unit. The cover may also be equipped with foam padding for the underside of the rigid top piece which provides for abrasion resistance for the OACU and will also provide for tilting of the cover when an unevenly distributed weight load is applied to the upper surface of the cover; the tilting facilitates runoff of ice and snow from the unit reducing the weight load bearing on the OACU. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustration of a conventional outdoor air conditioning unit. 
         FIG. 2  is an illustration of one preferred embodiment of a protective cover for a conventional outdoor air conditioning unit. 
         FIG. 3  is an underfoot view of a preferred embodiment of a protective cover for a conventional outdoor air conditioning unit. 
         FIG. 4  is an illustration of another preferred embodiment of a protective cover for a conventional outdoor air conditioning unit. 
         FIG. 5  is an illustration of another preferred embodiment of a protective cover for a conventional outdoor air conditioning unit. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Various embodiments of the present invention provide a protective cover for an outdoor air-conditioning unit (OACU) of a split system air conditioning system. 
     In  FIG. 1 , a conventional OACU  100  is illustrated. The OACU  100  comprises several mechanical and control elements housed inside a protective vented metal guard sheathing  110 . The protective vented metal guard sheathing has a solid flat lid  112  with a centralized nearly circumferential outlet grill  114 . The outlet grill  114  allows during unit operation for a fan  120  to discharge heat from a condenser unit  130 . The sides of the guard sheathing  110  are vented to allow cooling air to enter the OACU  100 . Due to the requirements to allow hot air to blow from the unit, the outlet grill  114  does not offer the underlying elements physical protection from falling debris nor does it offer protection from weather such as snow, hail, rain, and ultraviolet light (UV). 
     In  FIG. 2 , one preferred embodiment of a protective cover for an OACU is presented. A protective cover  200  for an OACU  100  is placed directly on top of the OACU  100 . The protective cover  200  is comprised of a panel  205  which rests on the OACU  100  and a skirt  210  which covers the sides of the OACU  100 . In one preferred embodiment, the thickness of the panel  205  is between about 2 inches and 2½ inches. In order to facilitate easy handling and carrying of the cover  200  it is desirable for the skirt  210  and the panel  205  to be comprised of a lightweight material such as plastic or the like. 
     The panel  205  is comprised of a rigid or semi-rigid material to offer protection from impact by falling objects to the OACU  100 . The panel is sized such that the entire upper surface of the OACU  100  is covered when the panel  205  is placed on the top surface of the OACU  100 . The panel  205  may be nominally larger than both the OACU  100  upper surface length and width. In one preferred embodiment of the invention, the panel  205  is sized such that it has essentially the same length and width of the stabilization pad  400  upon which the OACU  100  rests. 
       FIG. 3  depicts an underfoot view of the panel  205 . In the preferred embodiment depicted in  FIG. 3 , the underside of the panel  205  comprises a network of ridges  2056 ,  2057 ,  2058  which provide both strength to the panel and also reduce the panel weight. In the embodiment depicted, ridges are positioned in a rectilinear grid  2056 ,  2057  around a rectangular ridge  2058 . In the preferred embodiment depicted in  FIG. 3 , the height of the ridges is equivalent to the thickness of the panel edges  2059 ; so, if the panel  205  were placed on a flat surface larger than the panel  205  itself, the panel  205  would sit flat on the flat surface and essentially the entire bottom surface of the panel  205  would make contact with the flat surface. In another preferred embodiment, the vertical thickness of the panel edges is greater than the height of the ridges. This allows for the bottom of the panel  205  to have a lower elevation than the top of the OACU when the panel is placed on top of the OACU, which will help to keep the panel  205  in place when resting on the OACU. It should be readily apparent to those skilled in the art that the grid pattern may be modified without deviating from the principal of the invention. 
     Referring again to  FIG. 3 , the panel  205  is preferably constructed of an UV resistant material. Representative examples of such materials include, but are not limited to chloropolyvinylcopolymer (CPVC), a polyethylene copolymer rubber blend (such as the Black Pad manufactured by Diversitech of Pennington, N.J.), and the like. The panel  205  may also be coated with an UV resistant coating. One may use any one or more of the UV resistant coatings disclosed in U.S. Pat. Nos. 5,199,979 (UV resistant, abrasion resistant coatings), 4,680,232 (abrasion and UV resistant coating compositions), 5,938,831 (water and UV resistant clear coat sealant and finish for wood signs and other surfaces), and the like. The entire disclosure of each of these United States patents is hereby incorporated by reference into this specification. The UV resistance increases the life expectancy of the protective cover  200  as the cover  200  will be exposed to the outdoor elements for several months each year. 
     Referring again to  FIG. 2  and the preferred embodiment depicted therein, the skirt  210  may be attached to the panel  205  via readily available means. These means may include items such as staples. It may be desirable for the skirt  210  to be detachable from the panel  205  for several reasons. These include allowing the skirt  210  to be aired out and dried prior to being stored during the cooling season that the OACU  100  is in service, ease of storage, and ability to replace the skirt  210  if it is damaged. The skirt  210  is connected to the panel  205  through any of several readily available, means for attachment  220 . As depicted in  FIG. 2 , the means for attachment  220  may include items such as 2 part eyelet snaps  260 . In the depicted preferred embodiment, one part of the 2 part eyelet snap  260  is attached to the panel  205  via a screw or rivet and the other part of the 2 part eyelet snap  260  is attached to the skirt  210  via a rivet. The skirt  210  is preferably constructed of a flexible semi-permeable material which will allow gases such as air and water vapor to pass through, but do not allow solid objects to pass. A representative example of such a material is a polypropylene mesh manufactured by Meyco Products of Melville, N.Y. Other representative examples would be a semi-permeable fabric as that disclosed in U.S. Pat. Nos. 7,468,117 (method of transferring a wet tissue web to a three-dimensional fabric), 5,924,134 (protective garment with apertured closed-cell foam liner), 5,640,718 (Firefighter garment with combination facecloth and moisture barrier), and the like. The entire disclosure of each of these U.S. patents is hereby incorporated by reference into this specification. 
     In another preferred embodiment, not depicted, the skirt  210  is connected to the panel  205  using Velcro strips. 
     The protective cover  200  is designed to allow moisture that gets into the OACU  100  to escape which minimizes corrosion of the OACU  100  while it is not in operation. To facilitate this, the skirt  210  is sized such that the length of the skirt  210  is no more than about 75 percent of the height of the OACU  100 . It is preferred that the length of the skirt  210  is sized such that the skirt  210  is at least about 50 percent of the height of the OACU  100 . Due to the semi-permeable nature of the skirt  210 , trace amounts of moisture can enter the protective cover; but the semi-permeable nature of the skirt  210  also allows for this moisture to be removed from the OACU  100  when wind blows across the unit, when sunlight warms the unit, and through other natural drying processes. The choice of a semi-permeable skirt allows for the protective cover  200  to provide improved corrosion protection relative to existing OACU covers. 
     The skirt  210  is preferably secured to the sides of the OACU  100  via any of several readily available means. One such means is via a series of eyelets  270  placed in the lower portion of the skirt  210 . These eyelets  270  provide for connecting the skirt  210  to the OACU  100  via stretch cords  280 . At least one eyelet  270  will be attached on each side of the skirt  210 . OACUs from various manufacturers have louvers  108  in their sides that may be aligned vertically as shown in  FIG. 1 , or horizontally, or as rectangular openings. One end of each stretch cord  280  is placed in the eyelet  270  and the other end is placed in a louver. Prior to placing the other end in the louver, the stretch cord  280  is stretched to apply a downward force on the skirt  210  and keep it tight against the OACU  100 . It is preferable for each of the stretch cords  280  to have a length of at least about 4 inches and at most about 8 inches. It is more preferable for the stretch cords  280  to each have a length of about 6 inches. 
     To minimize the possibility of scratching the OACU  100  when the stretch cords  280  are attached to the OACU  100 , the stretch cord clips  285  may have a plastic coating applied by any readily available means. An example of such a stretch cord is the StarBrite Universal Bungee manufactured by Star brite Corp. of Fort Lauderdale, Fla. By not scratching the OACU  100 , the aesthetics of the OACU  100  are not compromised, nor are corrosion nucleation sites created. 
     For advertising purposes it may be desirable to show graphics on the skirt  210 . For example the distributor&#39;s name and logo may be so displayed. The advertising may be placed on the skirt  210  via screen printing. 
     As an alternative means of providing iconic artwork such as a logo for advertising, artwork could be printed on a plastic or metal plate and attached to the skirt  210  with pop rivets applied through holes in the plate and backed on the inside of the skirt with flat washers that engage an extended surface area of the skirt  210 , preventing the unintentional retraction of the pop rivet back through the skirt  210 . This method may be of particular value when the information to be applied is customized to the identification of the OACU  100  belonging to a particular building or address. 
       FIG. 4  depicts another preferred embodiment of the protective cover  200 . In the preferred embodiment, depicted in  FIG. 4 , at least one compressible cushion is placed on top of the OACU  100 . Representative cushions could include foam blocks, foam balls, synthetic sponges, and the like covered with an impermeable surface. As a representative example, a multiplicity of blocks may be used as the cushion. In the preferred embodiment depicted in  FIG. 4 , four blocks  500  are placed on the top of the OACU  100  and the protective cover  200  is set upon the multiplicity of blocks  500 . Each block  500  preferably compressible and has an impervious surface which will not absorb nor retain moisture. The impervious surface may consist of an elastic paint coating such as Duration Lifetime Coating manufactured by Sherwin-Williams of Cleveland, Ohio, a synthetic rubber coating such as Plasti Dip manufactured by Plasti Dip International of Blaine, Minn., and the like. Each block is preferably sized to a square with a length of approximately 4 inches. Each block  500  may be attached to the OACU  100  by readily available means which allow for temporary attachment such as Velcro or low adhesive glue (e.g. Removable Glue Stic glue manufactured by Avery Dennison of Brea, Calif.). It is preferred to use at least 3 blocks to support the protective cover  200 . The blocks  500  provide several benefits when installing the protective cover  200 . These benefits include ease of installation and removability. The compressibility of the blocks  500  also allow for a slight tilting of the protective cover  200  when a load is applied unevenly to the upper surface of the protective cover  200  (such an uneven load may be caused by snow drifting unevenly or from a branch falling onto a corner of the protective cover  200 ) which allows for snow and other objects to run or slide off the top of the protective cover  200 . The stretch cords  280  provide an additional benefit, when a non-evenly distributed load upon the protective cover  200  has been displaced due to a tilting of the protective cover  200 , the stretch cords  280  provide a force to relevel the protective cover  200 . 
     The cushion also reduces the potential for the protective cover  200  to scratch the upper surface of the OACU  100 . The cushion also provides cushioning to the OACU  100  in such an event as when an object strikes the protective cover  100 . 
     A soft foam with essentially no impermeable surface is not as desirable due to the potential for the soft foam to attract and retain moisture creating an environment suited for mold and fungus growth. 
     In another preferred embodiment, not depicted, a spray on foam material may be attached to the bottom of the protective cover. This spray on foam may then be coated with a thin sheet of plastic material or the like to prevent the spray on foam from sticking to the OACU  100  and to limit mold and fungus growth. 
       FIG. 5  provides a representation of another preferred embodiment of an OACU cover  300 . The OACU cover  300  is comprised of a panel  305  which rests on the OACU  100  and a skirt  310  which covers the sides of the OACU  300 . As depicted in  FIG. 5 , the height of the panel  305  is not uniform. The center  3051  of the panel is thicker than the side edges  3052  of the panel. The panel center  3051  thickness is represented as T 1  and the panel side edge  3052  thickness is represented as T 2 . T 1  is greater than T 2 . This creates a slope away from the center  3051  of the panel  305  and allows for moisture to drain away from the panel  305 . In this embodiment, there is also a lip  3053  along the lower portion of the side edge  3052  of the panel  305 . This lip  3053  allows moisture and debris falling off the panel to project away from the OACU  100 . In another preferred embodiment, the lip  3053  is less pronounced and the sides of the panel  305  flare out such that the lower portion of the panel  305  is wider than the upper portion of the panel  305 . Please note that in order to improve the view of the crown and side lip of the cover that these items are not drawn to scale. 
     Various embodiments of the present invention have been presented in this specification. The various embodiments used to describe the principles of the present invention are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged device.