Abstract:
A patio umbrella base has a base housing having an aluminum upper wall configured to define an interior space. The umbrella base further includes at least one cast iron piece positioned inside the interior space, and an aluminum seal provided over the cast iron piece(s) and securing the cast iron piece(s) to the upper wall. The aluminum seal can be provided by pouring molten aluminum over the cast iron piece(s) in a manner which completely covers the cast iron piece(s).

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to outdoor and patio umbrellas, and in particular, to an umbrella base that is encased by aluminum to prevent rust.  
           [0003]    2. Description of the Prior Art  
           [0004]    Outdoor and patio umbrellas (hereinafter referred to collectively as patio umbrellas) have become increasingly popular in recent years as people have found new and useful applications for them. For example, patio umbrellas have traditionally been used at patios and backyards of homes to provide shade from sunlight. Patio umbrellas have also been used extensively at swimming pools and other play or recreation facilities to provide shade. Recently, hotels (and in particular, resorts) and restaurants have been major purchasers of these umbrellas.  
           [0005]    Given the wide variety of use that patio umbrellas can be put to, it is important that an umbrella base be capable of providing adequate support to the patio umbrella. Conventional umbrella bases are made from one or more pieces of cast iron because cast iron is relatively inexpensive when compared to other materials, and can impart significant weight to provide the necessary support. For example, a conventional cast iron base is usually provided with a weight of about fifty pounds.  
           [0006]    Unfortunately, cast iron is susceptible to rust. Since patio umbrellas are used outdoors, the bases are exposed to water and the environment. After a period of time, the cast iron bases will rust, and may need to be replaced.  
           [0007]    Thus, there remains a need for an umbrella base that overcomes the drawbacks set forth above.  
         SUMMARY OF THE DISCLOSURE  
         [0008]    It is an object of the present invention to provide an umbrella base for use in supporting a patio umbrella in which the weight of the umbrella base is sufficiently heavy to provide adequate support and stability.  
           [0009]    It is another object of the present invention to provide an umbrella base for use in supporting a patio umbrella in which the umbrella base is provided in an inexpensive material.  
           [0010]    It is yet another object of the present invention to provide an umbrella base for use in supporting a patio umbrella in which the material used for the umbrella base is rust-proof.  
           [0011]    The objectives of the present invention are accomplished by providing a patio umbrella base having a base housing having an aluminum upper wall configured to define an interior space. The umbrella base further includes at least one cast iron piece positioned inside the interior space, and an aluminum seal provided over the cast iron piece(s) and securing the cast iron piece(s) to the upper wall. The aluminum seal can be provided by pouring molten aluminum over the cast iron piece(s) in a manner which completely covers the cast iron piece(s).  
           [0012]    Thus, the present invention provides an umbrella base whose exterior surfaces are all made of aluminum (which is rust-proof but very light in weight), while utilizing the aluminum to completely cover one or more cast iron pieces that are positioned inside the base housing. As a result, the present invention combines the advantages of cast iron (the weight and lower cost) and aluminum (rust-proof) in building an inexpensive, rust-proof and stable umbrella base. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a perspective view of a conventional patio umbrella.  
         [0014]    [0014]FIG. 2 is a cross-sectional view of an umbrella base according to one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    The following detailed description is of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating general principles of embodiments of the invention. The scope of the invention is best defined by the appended claims. In certain instances, detailed descriptions of well-known devices and mechanisms are omitted so as to not obscure the description of the present invention with unnecessary detail.  
         [0016]    [0016]FIG. 2 illustrates an umbrella base  10  according to one embodiment of the present invention. The umbrella base  10  has a base housing  12  having a central opening  14  from which a cylindrical shaft  16  extends. The central opening  14  can be provided with internal threads that are adapted to threadably engage external threads provided at the bottom of the shaft  16 , in a manner that is well-known in the art. The shaft  16  can be made from a metal material, such as aluminum. An annular ring  34  can be snap-fitted at the top of the shaft  16 . The ring  34  is preferably made from plastic and has an annular lip that is intended to support the pole  44  of a patio umbrella  40  (see FIG. 1), and to prevent the metal material at the top of the second shaft  16  from abrasive contact with the wood pole  44 . Therefore, the plastic ring  34  acts as a buffer that protects the wood pole  44  from abrasive rubbing against the metal material of the shaft  16 , which can occur as the patio umbrella  40  sways from wind and other forces.  
         [0017]    When the umbrella base  10  is to be used to hold and support a patio umbrella, such as a conventional patio umbrella  40  shown in FIG. 1, the bottom  42  of the pole  44  of the umbrella  40  is inserted into the shaft  16 . The shaft  16  has a locking mechanism  46  that can be rotated to secure the pole  44  inside the bore  28  of the shaft  16 . In a non-limiting embodiment of the present invention, the locking mechanism  46  can have a pin  50  having external threads  52  provided thereon, with a grip  54  provided at an end of the pin  50 . Each pin  50  is threadably screwed inside an opening  56  in the shaft  16 , with the pin  50  extending inside the bore  28  of the shaft  16  to push the pole  44  against the inner wall of the shaft  16  to secure the pole  44  inside the bore  28  of the shaft  16 .  
         [0018]    The base housing  12  has a dome-shaped upper wall  15  extending radially from a highest vertical elevation at the central opening  14  to the peripheral or circumferential edge  64  which is adapted to be positioned on the ground. A plurality of optional mini-bumps or rubber foots  66  can be spaced apart along the circumferential edge  64  to contact the ground, thereby raising the circumferential edge  64  slightly off the ground. The base housing  12  is preferably made from cast aluminum. A cast iron piece  70  (which can be embodied in the form of a generally dome-shaped circular piece of cast iron) is provided inside the base housing  12 . Cast iron is preferred because iron is both heavier and less expensive than aluminum, although aluminum is generally rust-proof. Aluminum  72  can be then used to seal the interior of the base housing  12  so that the cast iron piece  70  is completely protected by the aluminum base housing  12  and the aluminum seal  72 . Since the cast iron piece  70  is not exposed to the outside environment, rust can be prevented, thereby extending the useful life of the umbrella base  10  without significantly increasing the cost or compromising the weight and stability of the umbrella base  10 .  
         [0019]    Although FIG. 2 illustrates the provision of one cast iron piece  70 , it is possible to provide one or more cast iron pieces  70  that are positioned inside the base housing  12 . U.S. Pat. No. 6,113,054 discloses how more than one cast iron piece can be secured inside a base housing, and entire disclosure of U.S. Pat. No. 6,113,054 is hereby incorporated by this reference as though set forth fully herein.  
         [0020]    The umbrella base  12  can be made using the following method. First, the base housing  12  can be turned upside-down so that the domed-shaped upper wall  15  is now positioned like a bowl, and then the cast iron piece  70  is fitted inside the domed interior of the base housing  12 . If more than one cast iron piece  70  is to be provided inside the base housing, such additional cast iron pieces  70  can be secured at this time using the techniques described in U.S. Pat. No. 6,113,054. Next, melted aluminum  72  is poured inside the domed interior of the base housing  12  so that the melted aluminum  72  will flow around the cast iron piece(s)  70  and form a seal that completely protects the cast iron piece(s)  70  from exposure to the outside environment. The melted aluminum  72  is then dried to form the finished umbrella base  12 .  
         [0021]    While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.