Patent Abstract:
A spa cover is assembled from two or more molded foam sections. The sections may be molded from polystyrene, polyethylene, or a mixture of polystyrene and polyethylene. Panels are molded into the sections along mating edges, which panels cooperate to align the sections. The sections further include latches for holding the sections in alignment. The sections taper from a peak at the center of the cover to facilitate the run-off of rain, water sprays, or spills. Tie downs or inserts may be molded into the foam to facilitate the use of child safety straps to secure the cover to a spa. The cover may be sized to match known spa sizes, and may include a molded in decorative pattern and/or color.

Full Description:
The present application claims the benefit of U.S. Provisional Application Ser. No. 60/550,904, filed Mar. 8, 2004, which application is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to spa covers, and in particular to assembleable spa covers comprising a plurality of molded foam sections. 
     Spas are commonly owned and used to obtain the relaxing benefit of heated circulating water. Spa temperatures may be as high as one hundred degrees Fahrenheit. Either heating a spa to such temperatures, or maintaining such temperatures, may require a substantial use of power. Various spa covers have been devised to retain heat in spas, thereby saving power, and maintain temperatures suitable for use without extensive delays. Unfortunately, due to the size of known spas, a single piece cover is generally to large and heavy for easy manipulation. 
     U.S. Pat. No. 4,422,192 for “Spa or Hot Tub Cover,” describes an insulative cover which folds along a center line to reduce size and improve handling characteristic. The &#39;192 cover comprises a vinyl cover over a foam core. The cover of the &#39;192 patent still must be handled as a single unit and is of a size suitable for a typical spa, and therefore is quite heavy. 
     U.S. Pat. No. 5,685,031 for “Three-Piece Portable Spa Cover,” describes a cover which separates into two or more sections. The sections span across the spa, and are joined by “hinge-like” structure. The sections are made from molded plastic and filled with foam beads. Unfortunately, because the cover sections span across the spa, they are large and cumbersome to handle. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention addresses the above and other needs by providing a spa cover assembled from two or more molded foam sections. The sections may be molded from polystyrene, polyethylene, or a mixture of polystyrene and polyethylene. Panels are molded into the sections along mating edges, which panels cooperate to align the sections. The sections further include latches for retaining the sections in aligned cooperation. The sections taper from a peak at the center of the cover to facilitate the run-off of rain, water sprays, or spills. Holds or inserts may be molded into the foam to facilitate the use of child safety straps to secure the cover to a spa. The cover may be sized to match known spa sizes, and may include a molded in decorative pattern and/or color. 
     In accordance with one aspect of the invention, there is provided a spa cover comprising at least two sections. Each section comprises a molded foam body, molded-in panels for aligning adjacent sections, and latches for holding the sections in alignment. The foam may be polystyrene, polyethylene, or a mixture of polystyrene and polyethylene. The panels comprise male panels and female panels, and each section may include one of each gender of guide. The sections are preferably functionally interchangeable. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
         FIG. 1A  is a spa with a four section spa cover according to the present invention resting on top of the spa. 
         FIG. 1B  shows the spa cover separated into four sections. 
         FIG. 2A  is a top view of the spa cover showing knobs for engaging latches. 
         FIG. 2B  is a side view of the spa cover showing the knobs for engaging the latches. 
         FIG. 3  is a cross-sectional view of the spa cover taken along line  3 - 3  of  FIG. 2B . 
         FIG. 3A  is a more detailed cross-sectional view of one panel of the spa cover taken along line  3 - 3  of  FIG. 2B . 
         FIG. 4A  is a top view of a female panel molded into the sections of the spa cover to align the sections when the spa cover is assembled. 
         FIG. 4B  is a front view of the female panel molded into the sections of the spa cover to align the sections when the spa cover is assembled. 
         FIG. 4C  is a bottom view of the female panel molded into the sections of the spa cover to align the sections when the spa cover is assembled. 
         FIG. 5  is a cross-sectional view of the female panel taken along line  5 - 5  of  FIG. 4A . 
         FIG. 6A  is a top view of a male panel molded into the sections of the spa cover to align the sections when the spa cover is assembled. 
         FIG. 6B  is a front view of the male panel molded into the sections of the spa cover to align the sections when the spa cover is assembled. 
         FIG. 7A  is a cross-sectional view of the male panel taken along line  7 A- 7 A of  FIG. 6A . 
         FIG. 7B  is a cross-sectional view of the male panel taken along line  7 B- 7 B of  FIG. 6A . 
         FIG. 8  is a perspective view depicting the cooperation of the male panel with the female panel. 
         FIG. 9  is a perspective view of the knob for engaging latches. 
         FIG. 9A  is a top view of the knob for engaging latches. 
         FIG. 9B  is a side view of the knob for engaging latches. 
         FIG. 10  is a cross-sectional view of the knob taken along line  10 - 10  of  FIG. 9A . 
         FIG. 11  is a perspective view of a collar for knob. 
         FIG. 11A  is a top view of the collar for knob. 
         FIG. 12  is a cross-sectional view of the collar taken along line  12 - 12  of  FIG. 11A . 
         FIG. 13  is a perspective view of a second knob for engaging latches. 
         FIG. 13A  is a top view of the second knob for engaging latches. 
         FIG. 13B  is a side view of the second knob for engaging latches. 
         FIG. 14  is a cross-sectional view of the second knob taken along line  10 - 10  of  FIG. 13A . 
         FIG. 15  is a perspective view of a long knob. 
         FIG. 15A  is a side view of the long knob. 
         FIG. 16  is a perspective view of a long second knob. 
         FIG. 16A  is a side view of the long second knob. 
         FIG. 17A  is an embodiment of the present invention with four triangular sections. 
         FIG. 17B  is an embodiment of the present invention with four pie slice shaped sections. 
         FIG. 17C  is an embodiment of the present invention with four rectangular sections. 
         FIG. 17D  is an embodiment of the present invention with three rectangular sections. 
     
    
    
     Corresponding reference characters indicate corresponding components throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims. 
     A spa  12  with four rectangular sections  14  including four corners  10 ′ of a spa cover  10  according to the present invention resting on top of the spa  12  during a period of non-use is shown in FIG. lA. The spa cover  10  may be separated at mating (or engaging) edges  15  into four sections  14  as shown in  FIG. 1B  for easy handling. The sections  14  are preferable functionally interchangeable. The spa cover  10  is preferably molded from foam which is polystyrene, polyethylene, or a mixture of polystyrene and polyethylene, and more preferably molded from between approximately fifty percent and approximately eighty percent polystyrene and the remainder substantially polyethylene. A preferred material is ARCEL® manufactured by NOVA Chemicals in Alberta, Canada. ARCEL® is a trademark for a moldable copolymer (polystyrene and polyethylene) foam. 
     A more detailed top view of the spa cover  10  is shown in  FIG. 2A , and a side (or edge) view of the spa cover  10  is shown in  FIG. 2B . Knobs  16  visible on a top surface  10   a  of the spa cover  10  are provided for actuating latches which hold the sections  14  in alignment. The sections  14  are preferably tapered from a thick inside edge (or point)  15   a  to a thin outside edge  15   b  to facilitate runoff. 
     A cross-sectional view of the spa cover  10  taken along line  3 - 3  of  FIG. 2B  is shown in  FIG. 3 . Male panels  20  are shown in cooperation with female panels  22  to align the sections  14 . The panels  20  and  22  preferably extend between 60 percent and 90 percent of the length of the mating edges  15  of the sections  14 , and more preferably extend between approximately 71 percent and approximately 83 percent of the length of the mating edges  15 . Pairs of the knobs  16  cooperate with both the male and female panels  20  and  22  to hold the sections  14  in alignment. Tie downs (or inserts)  18  may be molded into the sections  14  to facilitate the use of child safety straps to secure the spa cover  10  to the spa  12 . 
     A more detailed cross-sectional view of one section  14  of the spa cover  10  taken along line  3 - 3  of  FIG. 2B  is shown in  FIG. 3A . The sections  14  are preferably interchangeable, and it not completely interchangeable, are preferably semi interchangeable (i.e., at least two of a multiplicity of panels making up the spa cover are interchangeable). Each section  14  includes one male panel  20  and one female panel  22  on consecutive edges. The male panel  20  has a male engaging edge  15   m  and the female panel had a female engaging edge  15   f.    
     A top view showing a horizontal outline of a female panel  22  molded into the sections  14  of the spa cover  10  to align the sections  14  when the spa cover  10  is assembled is shown in  FIG. 4A , a front view showing a vertical outline of the female panel  22  is shown in  FIG. 4B , and a bottom view of the female panel  22  is shown in  FIG. 4G . The female panel  22  includes molded-in portions  26  which cooperate with a foam molding to fix the female panel  22  to the sections  14 . The molded-in portions  26  are preferably triangular with a passage though the center to allow the foam material to better grasp the female panels  22 . The female panels  22  also include triangular receiving portions  30  having a triangular horizontal cross-section and a rectangular vertical cross section which cooperate with triangular projecting portions  28  having a triangular horizontal cross-section and a rectangular vertical cross-section (see  FIGS. 6A ,  6 B,  7 A,  7 B, and  8 ) of the male panels  20  (see  FIG. 6   a ) to align the sections  14 . Knobs  16   a  and  16   b  reside above slots (or mouths)  35 . The receiving portions  30  are preferably approximately one inch high and approximately two inches wide. Tongues  33  (see  FIG. 6A ) enter the slots  35  as part of the latching of the present invention. The tongues  33  are preferably triangular and subtend an angle  31  of approximately 90 degrees. 
     A cross-sectional view of the female panel  22  taken along line  5 - 5  of  FIG. 4A  is shown in  FIG. 5 . The knob  16   b  resides in a collar  40 . A male latch feature  34  extends downward from the knob  16   b . The knob  16   b  may be advanced into the collar  40  (and thus into the tongue  33 ) to engage a female latch feature  32  in the tongue  33  (see  FIG. 6A ) to latch the sections  14  together, and to thereby hold the sections  14  in alignment. The male latch feature  34  is preferably a tapered post or a cylindrical post having a tapered end. 
     A top view showing a horizontal outline of a male panel  20  molded into the sections  14  of the spa cover  10  to align the sections  14  when the spa cover  10  is assembled, is shown in  FIG. 6A  and a front view showing a vertical outline of the male panel  20  is shown in  FIG. 6B . The male panel  20  includes male molded-in portions  24  which cooperate with a foam molding to fix the male panel  20  to the sections  14 . The molded-in portions  24  are preferably rectangular with a passage though the center to allow the foam material to better grasp the male panels  20 . The male panels  20  further include projecting portions  28  having a triangular horizontal outline for cooperating with the receiving portions  30  (see  FIG. 4A ), and triangular tongues  33  for engaging the slots  35  (see  FIG. 4A ,  4 B). The tongues  33  include female latch features  32  which are engaged by male latch features  34  (see  FIG. 5 ) to hold the sections  14  in alignment. 
     A cross-sectional view showing a vertical outline of the male panel  20  taken along line  7 A- 7 A of  FIG. 6A  is shown in  FIG. 7A , and a cross-sectional view of the male panel  20  taken along line  7 B- 7 B of  FIG. 6A  is shown in  FIG. 7B . The female latch feature  32  is preferably a beveled passage through the tongue  33 . The projecting portions  28  and the molded in portions  24  preferably have a rectangular side-view (or vertical) cross-section, and are hollow with a horizontal center plates  28   a  and  24   a  respectively having an open center. 
     A detailed perspective view depicting the cooperation of the male panel  20  with the female panel  22  is shown in  FIG. 8 . 
     A perspective view of the knob  16   a  for engaging latches is shown in  FIG. 9 , a top view of the knob  16   a  is shown in  FIG. 9A , and a side view of the knob  16   a  is shown in  FIG. 9B . The knob includes threads  38   a  for cooperating with internal threads  38   b  (see  FIG. 12 ) in the collars  40 . 
     A cross-sectional view of the knob  16   a  taken along line  10 - 10  of  FIG. 9A  is shown in  FIG. 10 . The knob  16   a  includes the male latching feature  34  preferably having a cylindrical body and a tapered end  34   a  for engaging the female latching feature  32  (see  FIG. 6A ). 
     A perspective view of the collar  40  for cooperation with the knob  16   a  is shown in  FIG. 11  and a top view of the collar  40  is shown in  FIG. 11A . A cross-sectional view of the collar  40  taken along line  12 - 12  of  FIG. 11A  is shown in  FIG. 12 . The collar  40  includes internal threads  38   b  which cooperate with threads  38   a  on the knob  16   a.    
     A perspective view of a second knob  17   a  for engaging latches is shown in  FIG. 13 , a top view of the knob  17   a  is shown in  FIG. 13A , and a side view of the knob  17   b  is shown in  FIG. 13B . The knob  17   b  is pressed downward to latch and unlatch the sections  14 . A cross-sectional view of the knob  17   a  taken along line  10 - 10  of  FIG. 13A  is shown in  FIG. 14 , showing the male latching feature  34 . 
     A perspective view of a long knob  16   b  is shown in  FIG. 15  and a side view of the long knob  16   b  is shown in  FIG. 15A . The knob  16   b  is functionally equivalent to the knob  16   a , with the exception that the knob  16   b  is used at a thicker portion of the section  14 , and is therefore taller than the knob  16   a  (see  FIGS. 9 ,  9 A,  9 B, and  10 ). 
     A perspective view of a long second knob  17   b  is shown in  FIG. 16 , and a side view of the long second knob  17   b  is shown in  FIG. 16A . The long knob  17   b  is similarly used at a thicker portion of the section  14  and is similarly taller than the knob  17   a  (see  FIGS. 13 ,  13 A,  13 B, and  14 ). 
     Various other shaped spa covers may be manufactured according to the present invention, and are intended to come within the scope of the present invention. For example, second embodiment of the present invention with four triangular sections as shown in  FIG. 17A , a third embodiment of the present invention with four pie slice shaped sections as shown in  FIG. 17B , a fourth embodiment of the present invention with four rectangular sections as shown in  FIG. 17C , and fifth embodiment of the present invention with three rectangular sections as shown in  FIG. 17D . 
     While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.

Technology Classification (CPC): 4