Abstract:
A spa with spa working components integrally molded into a foam spa body. Certain working components, including the water circulation lines, electrical lines, air jet lines and a pump/heater housing are pre-assembled over a female mold. The working components are maintained in spaced relation from the female mold by spacer means. A male mold is placed over the female mold, defining a foam cavity between opposing sides of the female mold and the male mold and fully enclosing the spa components therein. Expandable foam is introduced into the foam cavity, integrally forming the spa body and encasing the enclosed working components. The female and male molds are removed from the spa body, and a flexible liner is installed over inner and outer sides of the wall of the spa body. The pump/heater unit is installed within its housing and attached to the electrical and water lines therein.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates generally to free-standing spas containing a body of hot water, used for therapy and relaxation. More particularly, the invention pertains to an integrally molded spa, in which certain working components of the spa are encased in a foam spa body at the time the spa is manufactured. A waterproof liner is then installed over the inner and outer sidewalls of the spa body to form a waterproof containment system.  
         [0003]     2. Description of the Prior Art  
         [0004]     Above-ground, free-standing spas, are well known in the prior art. One of the early designs was constructed from a plurality of redwood planks. Some of the planks were arranged in vertical relation and bound together with circumferential metal bands or rods to form the spa wall. Other planks were assembled in horizontal relation to form the spa floor. Known as redwood “hot tubs”, these spas typically included a water circulation and filtration system, and a number of strategically located water jets. Systems were also provided to introduce air bubbles into the flow of the water jets, to enhance the tactile experience of the outputted water. Dedicated water heaters of electrical, gas and solar design, were included to heat the spa water to the desired temperature.  
         [0005]     Although molded fiberglass or plastic spas were in use before redwood hot tubs became popular, they were primarily used indoors and integrated with a wood and tile surround and support structure. In that sense, the early molded spas were neither “free-standing” nor portable, as the surround and support structure was integrated with the spa to make the combination a permanent fixture of the bathroom or spa room.  
         [0006]     An example of a self-contained spa system in which the spa equipment is installed above ground level and at least a portion of the spa is installed in the ground, is illustrated in U.S. Pat. No. 6,381,768, for an In-Ground Spa System And Method For Installation Of Same. This arrangement, of course, requires ground excavation, and would not be considered portable.  
         [0007]     Current spa designs which are more portable, combine the molded fiberglass spa shell with a wooden base or support frame. Wooden slats or siding cover the sides of the base, effectively enclosing the spa shell and the working spa components, such as the motor, heater, plumbing, and electrical lines. Some spa constructions include foam insulation to increase the thermal efficiency of the spa. This foam insulation is typically sprayed over substantially all of the outer wall of spa shell and the pre-assembled plumbing lines and fittings connected to the shell.  
         [0008]     Yet other spa constructions employ a plurality of sections of synthetic resins, assembled to form a tub. U.S. Pat. No. 5,799,345, issued to Hansen et al. For a Spa Apparatus With Multiple Sections, is exemplary of this design. Installing a motor and pump within a plenum chamber formed between a tub wall and a container wall is shown in U.S. Pat. No. 5,794,280, for a Spa Apparatus With Het Transferring Hanging Interior Structural Liner. A spa having an interchangeable side skirt is disclosed in U.S. Pat. No. 5,685,032, for a Portable Spa With Integral Bottom Pan, Interchangeable Side Skirt, And Interlocking Cover. A self-contained spa system in which the spa equipment is installed above ground level and at least a portion of the spa is installed in the ground is illustrated in U.S. Pat. No. 6,381,768, for an In-Ground Spa System And Method For Installation Of Same.  
       SUMMARY OF THE INVENTION  
       [0009]     The spa of the present invention comprises an integrally molded, foam spa body as its major component. The spa body has a floor with a wall extending vertically and upwardly from the outer periphery of the floor. The spa body is preferably right-circular cylindrical in configuration, but it may also be formed in other configurations simply by adapting the principles employed herein to a mold of the desired shape. The spa body is formed through a two-step molding process, using an inner female mold and an outer male mold.  
         [0010]     The spa also includes various spa working components, such as water circulation lines, electrical lines, air jet lines and a pump/heater housing. In the first step of the molding process, the working components are pre-assembled and mounted in predetermined locations over, around, and in conjunction with the female mold. Using special spacer means, most of the working components are maintained in spaced relation from a cavity side of the female mold. Several of the working components, such as water and air inlet and outlet fittings, abut the cavity side of the female mold, so they will be readily accessible after the molding process is complete. These water and air fittings are connected to respective lines, which have connection ends entering the pump/heater housing.  
         [0011]     After all the working components are secured in place, a cavity side of the male mold is lowered over and secured to the cavity side of the female mold. The male mold thereby encircles and encloses the cavity side of the female mold, defining a foam cavity between opposing cavity sides of the female mold and the male mold. The working spa components also lie within the volume of the foam cavity.  
         [0012]     At least one access port is provided in the wall of the male mold. In carrying out the second step of the molding process the access port is opened, allowing the selective introduction of expandable foam into the foam cavity. The foam is typically either heat or chemically activated, expanding within the foam cavity to form an integrally molded spa body which encases the spa working components. After the foam has cured, the male mold is removed from the female mold and the female mold is removed from the formed spa body.  
         [0013]     The pump/heater unit is installed within the pump/heater housing and attached to the connection ends of the electrical and water lines extending therein. A spa control box and a timer may also be included in the pump/heater housing, so the spa heater and pump features may be manually controlled by the user or programmed for cyclical operation.  
         [0014]     A waterproof liner is installed over the floor and the inner and outer portions of the peripheral wall of the spa body. The liner, which is preferably flexible for economy and ease of assembly, forms a hydraulically impervious seal within the floor and inner portion of the peripheral wall, so it can retain the spa water. The liner also protects the foam spa body from wear and possible damage. Input and output fittings as well as any desired lighting fixtures are installed over the liner in the predetermined locations and connected to water, air or electrical lines extending to or abutting the inner portion of the peripheral wall. Air switches, for control of the pump and the lighting fixture, are also mounted at this time. The air switches are mounted within switch cavities formed when special spacer means supporting the pump/heater housing are withdrawn from the spa body.  
         [0015]     The bottom edge of the outer portion of the flexible liner includes a peripheral draw string or other attachment means, to secure the liner underneath the floor of the spa body. A perforated cover in the outer portion of the liner overlies an open side of the pump/heater housing. The perforations provide ventilation for heat generated by the pump. The cover may also be opened, providing for service access to the pump, heater, and control box. A spa cover, preferably made from vinyl material, is detachably secured over the upper edge of the peripheral wall to maintain heat and prevent entry of unwanted debris, when the spa is not in use. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a perspective view of the spa, showing the spa cover partially removed to reveal the inclined back rest, two of the water jets, and the two air switches, and with a portion of the spa liner being broken away to show the foam spa body;  
         [0017]      FIG. 2  is a fragmentary perspective view of the spa in an inverted position with the liner removed, showing the pump/heater within its housing, a portion of the water and air lines, and a spa light encased in the spa body;  
         [0018]      FIG. 3  is a perspective view of the spa&#39;s water and air plumbing components in pre-assembled condition, located in spaced relation over the female mold shown in broken line, the outer ring of the female mold being deleted for purposes of clarity;  
         [0019]      FIG. 4  is a perspective view of the female mold just prior to installation of the male mold, in preparation for step two of the molding process;  
         [0020]      FIG. 5  is a fragmentary, detail view of a portion of the female mold, a short pin spacer, and a water line;  
         [0021]      FIG. 6  is a fragmentary, detail view of a portion of the female mold, a clip spacer, and a water line;  
         [0022]      FIG. 7  is a fragmentary, detail view of a portion of the female mold, a retention magnet, a threaded plug, and a water and air jet fixture;  
         [0023]      FIG. 8  is a fragmentary, detail view of a portion of the female mold, a pair of large dual-diameter pin spacers, and a portion of the pump/heater housing;  
         [0024]      FIG. 9  is a transverse, cross-sectional view of the female and male molds with the working components mounted over and on the female mold, showing expandable foam being introduced into the spa cavity in the process of forming the spa body;  
         [0025]      FIG. 10  is a perspective view of the spa body being separated from the female mold, the spa body and the female mold being rotated to a vertical position for purposes of clarity;  
         [0026]      FIG. 11  is a perspective view of the spa body in an inverted position, prior to the installation of the pump/heater into the pump/heater housing;  
         [0027]      FIG. 12  is a perspective view of the spa body in an inverted position with the flexible liner partially installed; and,  
         [0028]      FIG. 13  is a view as in  FIG. 12 , but with the draw string passing through loops in the bottom edge of the liner pulled tightly to secure the liner in place over the spa body. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]     Turning now to the drawings, and in particular to  FIG. 1 , the invention comprises a therapeutic spa  11 , having as its major component an integrally molded spa body  12  with its exposed surfaces covered by a waterproof liner  13 . Spa body  12  includes floor  14  with a peripheral wall  16  extending vertically and upwardly from the floor&#39;s outer periphery. Floor  14  and wall  16  form the basic water containment structure of the spa. In the preferred embodiment disclosed herein, the spa body  12  is right-circular cylindrical in configuration. However the spa body may also be formed into other geometric configurations, such as hexagonal, pentagonal, octagonal, square, or rectangular in plan, by applying the present teachings to produce a spa body of the desired shape.  
         [0030]     Floor  14  includes on its inner side a lower horizontal section  17 , an intermediate horizontal section  18 , and an upper inclined section  19 . An inclined transition section  21  is provided between lower horizontal section  17  and intermediate horizontal section  18 . (See,  FIG. 2 ). The upper inclined section  19  comprises a wedge in configuration, having a linear forward edge  22  extending across intermediate horizontal section  18  and an arcuate trailing edge  23  in contingent relation with the inner side  24  of peripheral wall  16 . In this manner, horizontal section  18  provides a seat and inclined section  19  provides a backrest for the users of the spa.  
         [0031]     The spa also includes various spa working components  25  associated with the circulation, heating, and illumination of water contained within the spa. One of the principal features of the spa  11  is that most of these spa working components are at least partially, and in some instances entirely, encased within the integrally molded spa body  12 . It is this feature which provides a spa construction that is particularly economical both to manufacture and to operate.  
         [0032]     Making reference now to  FIGS. 3 and 4 , the spa body  12  is formed through a two-step molding process, using an inner female mold  26  and an outer male mold  27 . In the first step of the molding process, the spa working components  25  are pre-assembled and mounted in predetermined locations over, around, and in conjunction with the female mold  26 . Using specially designed spacer means, most of the working components are maintained in spaced relation from a cavity side  28  of the female mold  26 . One of the spa working components  25  includes a water pump inlet line  29  having a first connection end  31  mated to a water inlet  32  of pump  33 . Other working components are water pump discharge lines  34  having first connection ends  36  respectively mated to water discharge outlets  37  of pump  33 .  
         [0033]     To maintain a water line or pipe in spaced relation from the cavity side  28  of the female mold  28 , either a pin  38  or a saddle clip  39  may be employed. (See,  FIGS. 5 and 6 ). The size of pin  38  or clip  39  is such that the water line is typically 1″ to 2″ away from the cavity side  28 . Other arrangements are employed where a water line inlet or discharge end must penetrate the peripheral wall  16 . For example, in  FIG. 7  an air mixing venturi fitting  41  is shown. This particular fitting is an “in series” fitting, as it has an incoming and an outgoing water discharge line  34 . The fitting also has an incoming air line  42 , delivering air into the fitting and introducing air bubbles into the discharged water. The flange  43  of the fitting must be maintained in contingent relation with the cavity side of the mold  26 , so that when the mold is removed, there will be ready access to the fitting. For that purpose, a threaded metal plug  44  is installed temporarily into the fitting  41 . A magnet  46  is permanently installed on the outer side of mold  26 . An aperture  47  in the wall of the mold ensures that the plug  44  will be magnetically attracted by the magnet  46 . When the fitting  41  and its associated lines are assembled, the magnetic forces are sufficient to hold these working components stationary in the pre-determined location for the fitting.  
         [0034]     Yet another feature of the spa  11  is the utilization of the volume created behind the upper inclined section  19 , to house the pump  33 , a water heater  48 , and a spa control box  49 . In effect, the spa&#39;s internal backrest creates a useful housing integrating additional spa working components into the spa body  12 . Preferably, a separate pump/heater housing  51  is located immediately behind upper inclined section  19 . Pump/heater housing has a wall portion  52  intruding inwardly from peripheral wall  16 , and an open portion  53  accessible from the outer side of peripheral wall  16 . Pump/heater housing  51  may be manufactured from plastic, fiberglass, metal, or foam.  
         [0035]     As a spa working component, housing  51  must also be maintained in spaced relation from the female mold  26  during the molding process. For that purpose, a pair of large pins  54  are provided to support and maintain pump/heater housing  51  in its pre-determined location. Housing  51  has its wall portion  52  spaced from one portion of mold  26  and its open portion  53  in contingent relation with another portion of mold  26 . (See,  FIG. 9 ).  
         [0036]     Pins  54  have upper and lower sections of differing diameters for the second function they perform after the molding step. Pins  54  are permanently attached to mold  26 . Thus, when the mold  26  is withdrawn from spa body  12 , a pair of passageways  56  are created in the spa body  12 . (See,  FIGS. 10 and 11 ). These passageways are sized and configured to house a pair of air switches  57  and their associated electrical lines, which are effective to control operation of the motor  33  and the spa light  55 .  
         [0037]     Completing the first step of the molding process, the outer male mold  27  is next placed over the female mold  26 , mating with a respective circular edge of the female mold, as shown in  FIG. 4 . It should be noted that a cavity side  58  of male mold  27 , includes a plurality of impression blocks  59 , strategically located in a relatively thick portion of floor  14 . The purpose of blocks  59  is to form voids  61  in the underside of the spa floor, which serve to reduce the amount of foam required to form the spa body without compromising its strength. In addition, a pair of impression ridges  62  are also provided on the cavity side  58  of male mold  27 . Impression ridges  62  form channels  63  in the spa body  12  to accommodate electrical wiring extending to one or more spa lights  55 .  
         [0038]     With the outer male mold  27  installed over the female mold  26 , a foam cavity  64  is defined between the opposing cavity sides of the female mold and the male mold. As described above in the first step of the molding process, the working spa components have already been pre-assembled and installed in spaced relation from the female mold. Thus, the working spa components also lie within the volume of the foam cavity  64 .  
         [0039]     One or more access ports  66  are provided in the wall of the male mold. In carrying out the second step of the molding process, valves (not shown) in the access ports  66  are opened, allowing the selective introduction of foam pellets  67  into the foam cavity  64 . After the foam cavity is filled with foam pellets, steam is introduced into the foam cavity and the pellets structurally merge to form the spa body  12 . Other methods to introduce and cure the foam well known in the art, may be used as well. For example, a two-stage foam process using pellets and a chemical activator is a well-known equivalent. In either case, after the pellets have been activated to expand and/or merge into a solid within the foam cavity, the integrally molded spa body  12  is formed which encases the spa working components. After the foam has cured, the male mold  27  is removed from the female mold  26 , and then the female mold  26  is removed from the formed spa body. (See,  FIG. 10 ).  
         [0040]     Next, the remainder of the spa working components are installed. The pump  33  including the heater  48 , are installed through the open portion  53  into the pump/heater housing  51 . Water inlet  32  and water discharge outlets  37  are attached to the first connection ends of the water inlet line and the water discharge lines. The pump and heater have a power line with a connector which is plugged into the spa control box  49 . The spa control box may include a timer (not shown) so the spa heater and pump features may be programmed for cyclical operation. Air switches  57  are installed in respective passageways  56 . One air switch is connected to power line  69 , leading to spa light  55 . This line is installed in foam channel  63 , previously formed during the molding process as discussed above. This air switch also includes a line with a connector which is plugged into the spa control box  49 , for power. Another air switch has a power line  71  with a connector which is also plugged into the spa control box. This switch completes the circuit supplying power to the pump and heater, for manual operation thereof.  
         [0041]     A hardening agent may also be applied to the upper edge of the peripheral wall  16 , at this time. This agent forms a more rigid protective coating to that portion of the wall which will likely be subjected to greater stresses and wear, over time. However, applying this agent is merely precautionary and optional, as it has been determined that the untreated wall is sufficiently strong and durable for most spa use.  
         [0042]     The waterproof liner  13  is then installed over the floor  14  and the inner and outer sides of the peripheral wall  16  of the spa body  12 . The liner, which is preferably manufactured from a vinyl material, forms a hydraulically impervious seal within the floor and the inner side of the peripheral wall, so the spa can retain water. The liner also protects the foam spa body from wear and possible damage, and provides and attractive appearance to the spa  11 . As shown in  FIG. 12 , the liner extends down the outer side of the peripheral wall, and terminates at a bottom edge provided with a plurality of flap segments  72 . A cord  73  is looped through each of the flap segments, and then pulled tight before the ends are tied into a knot. In this manner, the liner  13  is secured over the spa body  12 .  
         [0043]     It should also be noted that waterproof liner  13  can be manufactured from different material and can be installed in and over the spa body in a different manner, than that just described. For example, liner  13  could be a pre-manufactured rigid shell, either molded or vacuum formed. In that circumstance, the rigid liner would be dropped into place over the spa body prior to the final installation of the spa&#39;s interior fixtures, explained below. Waterproof liner  13  can also be a sprayed-on shell, using material such as polyurethane or an equivalent curable spray material. A sprayed-on shell for the liner  13 , would have the advantage of readily customizing the colors and texture of the liner to meet the customer&#39;s specific needs.  
         [0044]     After the spa is righted, final installation of fixtures within the spa can be completed. The liner  13  is carefully cut in those appropriate places where fixtures must pass through or be mounted over the liner. These fixtures would include the spa light  55 , water inlet fixture  74 , and water discharge fixture  76 . These fixtures are mounted in tight relation over the liner  13 , so a secure hydraulic seal is formed. Spa light  55  is connected to its low voltage power line  63 , before being mounted over liner  13 .  
         [0045]     Foraminous covers  77  are zippered to liner  13  over open portions  53  of the pump/heater housing  51 , to provide both ventilation for the motor  33  and easy access to other working components for servicing and programming. Lastly, a spa cover  78 , preferably made from vinyl material, is detachably secured over the upper edge of the peripheral wall to maintain heat and prevent entry of unwanted debris, when the spa  11  is not in use.