Abstract:
A method and apparatus for providing a substantially laminar flow of water in a swim spa is includes providing a basin holding a fluid. The method includes circulating water from the basin through at least one laminar flow swim spa jet, creating a substantially laminar flow of the fluid directed from one end of the swim spa. Each of the at least one laminar flow swim spa jet comprises a plurality of parallel, cylindrical tubes that reduce turbulence from the fluid as the fluid passes through the plurality of parallel, cylindrical tubes.

Description:
FIELD 
       [0001]    This invention relates to the field of spas and more particularly to a system for providing comfort when swimming in a swim spa. 
       BACKGROUND 
       [0002]    Spas and pools provide places for people to relax as well as exercise. By controlling the temperature of the water within spas and pools, users are able to enjoy and use their spas and pools for most of the year, by heating the water in places with cold temperatures in the winter and, even, cooling the water in places with very warm temperatures. 
         [0003]    Many people exercise in water for many reasons. Water exercise, also called aquatics or water therapy, offers a very good cardiovascular workout. Exercise in water is especially helpful in cases where a land-based exercise program such as jogging is not possible due to pain, decreased bone density, disability, etc. A person within water is buoyant to some extent, thereby counteracting gravity and placing less stress on the person&#39;s skeletal and muscular system. Water provides resistance to movement to help strengthen the person&#39;s muscles, while reducing the risk of injury due to balance issues. Since the temperature of the water is easily controlled, exercise in water is possible during many climatic conditions during which land-based exercise is not practical. For example, a person is able to exercise in a cooled body of water when the air temperature is over 100 degrees, a temperature that may prove dangerous for someone running or jogging. Similarly, a person is able to exercise in a heated body of water when it is below zero outdoors with snow and ice on the ground. 
         [0004]    Many homes, communities, and businesses such as hotels have heated pools, some have cooled pools. 
         [0005]    In order to take advantage of such pools, one must either have substantial yard space for their own private pool or one must travel to a location where there is a public or shared private pool. Often, the need to travel to the pool, dry off, and travel back home discourages user from taking advantage of such facilities. If users with limited space (indoor and/or outdoor) do not find it easy or convenient to use shared pools for exercise, there is an alternative that occupies very little space relative to the space occupied by a pool, that is, a swim spa. In a swim spa, the user is able to “swim in place,” against a current of water. The swim spa uses pumps to circulate water from the swim spa out jets at one end of the swim spa, thereby creating a current within the swim spa through which the user swims against, thereby maintaining a position within the swim spa while they swim for exercise. 
         [0006]    Unfortunately, prior swim spa designs using pumps and rotating blades create turbulence that makes it difficult or uncomfortable to swim, something like swimming towards the propeller of a boat. This turbulence often leads to the user moving off-center within the swim spa, possibly leading to the user hitting the sides of the swim spa. It is much more desirable to swim in an even, laminar flow of water similar to swimming upstream in a wide river or in a water current. 
         [0007]    What is needed is a system that will provide a smooth, laminar flow of water within a swim spa. 
       SUMMARY 
       [0008]    In one embodiment, a swim spa is disclosed including a basin for holding a fluid (e.g. spa water) defined by walls and a bottom with a cavity behind an end wall of the walls. At least one propeller is rotatably housed within the cavity and at least one grate in the end wall fluidly couples the fluid in the basin to the cavity (e.g. provides a flow of the fluid from the basin). A device is coupled to and rotates the propellers. In front of each propeller is a laminar flow swim spa jet mounted in the end wall. Each of the laminar flow swim spa jets is positioned in front of one of the propellers such that as the propellers rotates, the fluid is drawn in from the at least one grate and directed out of the at least one laminar flow swim spa jets. 
         [0009]    In another embodiment, a method of providing a substantially laminar flow of water in a swim spa is disclosed including providing a basin holding a fluid. The method includes circulating water from the basin through at least one laminar flow swim spa jet, creating a substantially laminar flow of the fluid directed from one end of the swim spa. Each of the at least one laminar flow swim spa jet comprises a plurality of parallel, cylindrical tubes that reduce turbulence from the fluid as the fluid passes through the plurality of parallel, cylindrical tubes. 
         [0010]    In another embodiment, a swim spa is disclosed including a basin for holding a fluid such as spa water defined by walls and a bottom and a cavity behind an end wall of the walls of the basin. Two propellers are rotatably housed within the cavity and at least one grate fluidly couples the fluid in the basin to the cavity. Two motors, each coupled to one of the propellers, rotate the two propellers. In front of each propeller is a laminar flow swim spa jet. As the propellers rotate, the fluid is drawn in from the at least one grate and directed out of the cavity through the two laminar flow swim spa jets. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
           [0012]      FIG. 1  illustrates a cross-sectional view of the active end of a swim spa of the prior art. 
           [0013]      FIG. 2  illustrates a perspective view of a swim spa. 
           [0014]      FIG. 3  illustrates a top plan view of the swim spa. 
           [0015]      FIG. 4  illustrates a perspective view of the swim spa showing the active end. 
           [0016]      FIG. 5  illustrates a perspective view of a propulsion system of the swim spa. 
           [0017]      FIG. 6  illustrates a cross-sectional view of the active end of a swim spa showing the propulsion system and laminar flow jets. 
           [0018]      FIG. 7  illustrates a cross-sectional view of the laminar flow jets. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
         [0020]    Referring to  FIG. 1  illustrates a cross-sectional view of the active end of a swim spa of the prior art is shown. There are many known configurations of swim spas. Some utilize typical spa water pumps to force water through jets at the active end of the swim spa  1 . The example shown utilizes a motor driven propeller to generate water currents within the swim spa  1 . In such, a motor  4  is mounted outside of the shell of the swim spa  1  and a shaft of the motor  4  passes through the shell and is terminated with a propeller  6 . When the motor  4  is powered, the shaft  5  rotates, thereby rotating the propeller  6  and directing water from intake grills  3  out, through an opening covered with a grill  2 . In such a system of the prior art, since the shaft  5  passes through the shell of the swim spa  1 , a seal  7  is needed to prevent leakage of water around the shaft  5 . Such seals  7  are prone to failure due to the adverse conditions presented by treated water (e.g. chlorinated water) as well as extended use while the shaft continuously rotates, leading to a major failure point for such swim spas  1 . Additionally, a sufficient cavity is needed to supply water around the propeller  6  and an additional cavity or cover is needed around the motor  4  to protect the motor and prevent humans and animals from accessing the motors. 
         [0021]    Ignoring the problems stated above, swim spas  1  of this or other existing designs present varying degrees of turbulence to the swimmer. In the example of the prior art shown in  FIG. 1 , the water flowing from the propeller  6  will not be laminar and will likely resemble the turbulence that is seen behind a boat propeller when it moves quickly through the water. It is not comfortable to swim in such turbulence. 
         [0022]    Existing swim spas of other designs also present turbulence. For example, is prior art swim spa systems that use a spa pump connected to several jets at one end of a swim spa, variations between each jet and directionality of each jet leads to significant turbulence. 
         [0023]    Referring to  FIGS. 2 and 3 , a perspective view and a top plan view of a swim spa  10  is shown. Although many sizes, shapes, and constructions of a swim spa  10  are anticipated, the swim spa  10  is shown as an example of one construction. In this example, a cavity  20  is filled with water and is at the non-occupied end of the swim spa  10 . Wiring for power to the motors  34  (see  FIG. 5 ) are not shown, but preferably pass through tubes  22  that don&#39;t require perfect seals, in that the tubes  22  travel above the water line to deliver the wires to sources of power (not shown), control circuits (not shown) and/or controls  24 . 
         [0024]    For brevity purposes, the swim spa  10  is shown without water and without a swimmer. In use, the swim spa  10  is filled with water (e.g. H 2 O and other materials typically found in pools and spas) to a level close to the upper edge of the basin  11 . The swimmer (not shown) positions head toward the active end while the swim spa  10  operates to present a mostly laminar flow of the water directed at the swimmer, so that, as the swimmer swims against the laminar flow of water, the swimmer maintains position within the basin  11 . 
         [0025]    Referring to  FIG. 4 , a perspective view of the swim spa  10  showing the active end is shown. The active end of the swim spa  10  includes one or more water input ports covered by grates or screens  23 . The grates or screens help prevent users from reaching inside the cavity  20  (see  FIG. 6 ) and potentially contacting the propellers  36  (see  FIG. 5 ). 
         [0026]    The user-ends of the laminar flow spa jets  32  are shown. In position, preferably below the water line and substantially centered at the active end of the swim spa  10  is/are one or more laminar flow swim spa jets  32 . 
         [0027]    In this example, two laminar flow spa jets  32  are shown, though any number and/or configuration of laminar flow spa jets  32  is anticipated, including one laminar flow spa jet  32 . As will be described with  FIG. 7 , the laminar flow spa jets  32  produce a substantially laminar flow of water from a potentially turbulent flow of water (of course, provided a laminar flow, the laminar flow spa jets  32  will still produce a substantially laminar flow). The motors  34  and propellers  36  are positioned behind the laminar flow spa jets  32  as shown in  FIG. 6 , directing the flow of water through the capillary tubes  38  of the laminar flow spa jets  32 . The capillary tubes  38  of the laminar flow spa jets  32  cause the water to flow in a more orderly, substantially laminar flow towards the swimmer (not shown). 
         [0028]    Referring to  FIG. 5 , a perspective view of a propulsion system of the swim spa is shown. In this view, the laminar flow swim spa jets  32  include an outer surface  31 . It is anticipated that the laminar flow swim spa jet(s)  32  is/are mounted to the active end of the swim spa  10  in any way known, including, but not limited to, screws, adhesive, etc. In some embodiments, the laminar flow swim spa jet(s)  32  is/are formed as part of the surface at the active end of the swim spa  10 , for example, during the molding process. 
         [0029]    In this example, a propeller  36  attached to a motor  34  is mounted behind each laminar flow swim spa jet  32 , though there is no requirement for a one-to-one correspondence. For example, in other embodiments, one propeller  36  attached to one motor  34  is mounted behind a grid of laminar flow swim spa jets  32 . Although not required, it is preferred that a diameter of the propeller  36  be similar to a diameter of the outer surface  31  of a corresponding laminar flow swim spa jet  32 . 
         [0030]    In this example, two motors  34  driving two propellers  36  behind two similarly sized laminar flow swim spa jet  32  is shown. In other embodiments, it is anticipated that there are multiple motor  34 /propeller  36  combinations of different sizes, such as one large motor  34 /propeller  36  and two small motors  34 /propellers  36 . In this example, it is also anticipated that each of the laminar flow swim spa jets  32  have approximately equivalent diameters as that of the propellers  36 ; in this example, one large laminar flow swim spa jet  32  and two small laminar flow swim spa jets  32 . In other embodiments, a single motor  34  drives multiple propellers  36  through any means known such as pulleys, gears, etc. 
         [0031]    In some embodiments, the propellers  36  rotate in the same direction while in other embodiments, some of the propellers  36  rotate in opposite directions to the other propellers  36 . 
         [0032]    The motors  34  are mounted to any type of bracket  38  for attaching to the swim spa  10 . 
         [0033]    Referring to  FIG. 6 , a cross-sectional view of the active end of a swim spa  10  showing the propulsion system and laminar flow jets  32  is shown. In this, the motor  34  is shown mounted to the wall  20  of the active end of the swim spa  10 . A cavity is formed in the active end of the swim spa  10  through which water enters into the cavity from the basin  11  through grills  23  and is pushed out of the cavity by propellers  36  driven by motors  34 . At the propellers  36 , the water is turbulent, but before returning to the swim spa basin  11 , the water is channeled to flow through laminar flow swim spa jets  32 . The tubes within the laminar flow swim spa jet  32  greatly reduce the turbulence that is presented the basin  11 , and eventually to a swimmer within the basin  11 . 
         [0034]    In this example, though not required, submersible motors  34  are used (e.g., motors often known as trolling motors). By using submersible motors, there is no need to install the shaft through a seal in the shell of the swim spa  10  (as in the prior art described with  FIG. 1 ). Wiring from the motors is easily routed through tubes  22  (see  FIG. 2 ) to a location above the anticipated water line, eliminating the need for perfect seals. Since the motor&#39;s  34  shaft does not need to pass through an opening in the shell of the swim spa  10 , it is now possible to pre-mount the propeller  36  to the motor&#39;s  34  shaft and it is also possible to reduce the length of the motor  34 &#39;s shaft. 
         [0035]    Referring to  FIG. 7 , a cross-sectional view of the laminar flow jets  32  is shown. Each laminar flow swim spa jet  32  is a bundle of tubular passages of sufficient length as to channel a flow of turbulent water entering a first end of the bundle of tubular passages into a substantially less turbulent flow of water exiting a distal end of the bundle of tubular passages. Any number greater than one tubular passage is anticipated, though a larger number of tubular passages is preferred such as between 5 and 50. There is no limit on the length of the tubular passages, but the longer the tubular passage, the greater the reduction in turbulence, but of course there is a practical limit due to space constraints. 
         [0036]    Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
         [0037]    It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.