Patent Application
20130212797
Embodiments of the present invention relate generally to pool cover components that are more resistant to corrosion than current cover assemblies. Certain embodiments provide polymer hubs that separate potentially corrosive-prone components from one another. Other embodiments provide a coating on one or more of the components to prevent electrical conductivity, which often leads to corrosion of certain metals.
The water in pools and spas must be treated in order to prevent growth of algae or bacteria that may flourish in large bodies of untreated water. Many pools and spas are treated by traditional chlorination sanitation—direct addition of chlorine to the water. However, more and more pools and spas are being installed or retrofitted with salt water chlorinators. Salt water chlorinators use dissolved salt (NaCl) as a store for the chlorination system. The chlorinator uses electrolysis to break down the salt into its individual elements, one of which is chlorine. The resulting chemical reaction eventually produces hypochlorous acid (HClO), and sodium hypochlorite (NaClO), which are the sanitizing agents already commonly used in swimming pools. As such, a saltwater chlorination system utilizes a chlorine generator instead of direct addition of chlorine.
One of the benefits of a salt chlorination system in a pool or spa is the convenient and constant delivery of pure chlorine-based sanitizer. Such systems help eliminate chloramines, which are the irritants that give traditional pools their caustic smell and can cause burning eyes for swimmers. Salt chlorination systems use electrolysis, which burns off the chloramines in the same manner as traditional shock (oxidizer) and reduces dissolved alkali minerals in the water. However, there are also some disadvantages to the use of salt water chlorination systems, one of which is that salt conducts electricity, which can cause galvanic corrosion.
When salt is in the presence of two dissimilar metals, it can turn the system into a battery of sorts, with one of the electrodes giving off an electron which creates corrosion. This corrosion increases when there is liquid in the “battery,” such that adding salt to a pool system creates an electrolyte of sorts (e.g., when the salt is dissolved in a solvent (e.g. water), it becomes an electrolyte with free ions). This corrosion can damage some metals, as well as stone or other pool decking materials. Many pool equipment manufacturers will not warranty stainless steel products damaged by saline pools.
There is thus a need to provide protective features for various components to be used in connection with salt water pools, particularly those components that come into contact with the water on a recurring basis. For example, some mechanical systems that may be used in connection with pools and spas are pool cover systems, which can be activated to roll a cover across a pool or spa surface for protection, money savings, and/or safety reasons. Pool covers can save pool owners money by saving on heat, chemicals, equipment and pool cleaning, and other operating costs; they can save lives by providing a safeguard against accidental pool entry by an unattended child; they can save time by keeping dirt, leaves and other debris out of the pool when the pool is covered; and they can save energy by reducing heating costs. However, if the pool cover extension and retraction system components become corroded, this can damage the ability of the system to work properly. Accordingly, improvements to pool cover assembly components are needed in order to help ensure that they remain corrosion-free, even when used in connection with a salt water pool.
Embodiments of the invention described herein thus provide pool cover components that are more resistant to corrosion than current cover assemblies. Certain embodiments provide polymer hubs that separate potentially corrosion-prone components from one another. The polymer hubs isolate dissimilar metals, preventing them from conducting electricity and speeding the corrosion process. Other embodiments provide a coating on one or more of the components to prevent electrical conductivity.
Embodiments of the present invention provide covers for pools that are designed and manufactured having certain features that render the pool cover systems and assemblies more corrosion resistant than current pool cover assemblies. The new designs provided help to resist galvanic corrosion or otherwise inhibit degradation of the components.
Both the central plate 12 and the hub stem 18 are provided as discrete elements, rather than as a unitary piece. It has been found that by providing these elements as separate components, greater interchangeability options may be provided, as shown in
Both the central plate 12 and the hub stem 18 are manufactured of stainless steel, which does not corrode as easily as cast (or billet) aluminum, the material commonly used in the pool industry for these elements. An aluminum on aluminum configuration creates corrosion, even when the aluminum is anodized or powder coated, primarily because cast aluminum is more porous than stainless steel and the anodized portions or powder coating can flake. Accordingly, providing these cover components 12, 18 out of stainless steel or another metal that is less prone to corrosion reduces corrosion issues, and is an advancement over the current technology. Specifically, both steel and aluminum react with oxygen to form a passivation layer that protects the underlying metal. That layer is aluminum oxide for aluminum and chromium oxide for stainless steel. Depending on the alloys and the manufacturing process used, stainless steel is usually significantly more resistant to corrosion. Accordingly, using stainless steel parts to replace cast aluminum parts significantly eases these problems. (Depending on their relative locations on the anodic index, some dissimilar metals can be joined without increasing corrosion; however, when stainless steel contacts aluminum, it acts as a cathode and aluminum as an anode, which causes the aluminum to corrode as it gives up electrons.) Accordingly, by creating methods to keep these two metals from ever making contact in the updated design, many of the corrosion problems of the prior art are reduced or eliminated.
Another factor that also reduces corrosion problems is the use of polymer hubs 24 secured on the other side of the central plate 12. The polymer hubs 24 insulate dissimilar metals (e.g., the stainless steel end hub and the aluminum drum, described in more detail below) from one another. The polymer hubs 24 are raised elements of a polymer, plastic, or rubber-like material that are secured to central plate 12. As shown in
In use, two completed hub assemblies 10 cooperate on either end of a tube 28 in order to create a drum assembly 48, as shown in
An example of a tube 28 that forms the drum 48 is shown in
Another component used in connection with pool cover systems is a rope reel 34. In the past, these components have been made of cast aluminum as an integral component and then anodized and/or powder coated in an attempt to protect them from corrosion. However, corrosion has still been a problem with pool cover systems reels, and the present inventors have developed a solution. As shown in
Changes and modifications, additions and deletions may be made to the structures and methods recited above and shown in the drawings without departing from the scope or spirit of the invention and the following claims.
This application claims the benefit of U.S. Provisional Application Ser. No. 61/601,590, filed Feb. 22, 2012, titled “Components of Cover Assemblies for Pools and Spas,” the entire contents of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61601590 | Feb 2012 | US |
