Hydro-therapy spa jet nozzle

#This invention relates generally to tubs and spas, and, more particularly, to a jet for aerating a liquid flow, and the methods by which the jet works.

#Hydro-therapy is a useful form of physical therapy. In hydro-therapy, patients rest in a body of water within a spa, while their anatomy is massaged by an aerated water stream flowing out of a hydro-therapy spa jet. The jet provides this stream of aerated water by directing an aerated water stream through a nozzle, into the body of water, and against the portion of the patient's anatomy where the massaging action is desired. A high water stream speed is necessary for aerating the water stream; however, high water stream speeds produce strong aerated water streams that quickly become uncomfortable on many parts of a patient's anatomy. Furthermore, when directional control is incorporated into hydro-therapy spa jets, back pressure generally results, interfering with the process of aeration. Accordingly, it has been an important aim of hydro-therapy spa jet designers to design hydro-therapy spa jets that produce a well-aerated stream of water that is not uncomfortably strong, and may be directionally controlled.

#A common form of hydro-therapy spa jet includes a first nozzle that accelerates a stream of water, feeding it into a second nozzle. The accelerated water becomes aerated in the second nozzle, and then passes out through a third nozzle into a body of water with enough penetration to create a massaging action. Proper aeration produces a stream of water that is particularly penetrating. While this design is widely used in the hydro-therapy spa and tub business, it is unforgiving to changes in the first nozzle, air chamber, and third nozzle. Any changes in these areas can cause vast fluctuations in the operation of the jet and can even cause the jet not to draw air, which stops the massaging action.

#A hydro-therapy spa jet 101 according to the present invention is shown in FIG. 1. The system includes a housing 102 defining a passage for water having an upstream end 103 and a downstream end 104. The housing forms an inlet connection 105 containing pressurized water, and defines an air inlet chamber 106. The housing contains a first nozzle 107, a second nozzle 108, and a third nozzle 109 having a body 110 and vanes 111. The first nozzle accelerates water from the inlet connection, directing a stream of it to flow into and through the air inlet chamber defined within the housing. The air inlet chamber provides air to be entrained by the accelerated water stream, the accelerated water stream thus becoming an aerated, accelerated water stream. The aerated, accelerated water stream is then received in the second nozzle, which diverges to decelerate the aerated, accelerated water stream. The second nozzle, in turn, directs the aerated water stream into the third nozzle where it is further slowed, and may be directionally turned, to produce a comfortable, directionally-controlled, aerated water stream. The aerated water stream is propelled into a body of water 112 and against a person's anatomy, and is not uncomfortably strong. The water stream, extending from the inlet connection to the body of water, defines upstream and downstream directions within the water stream, and for objects in contact with the water stream. Objects in contact with the water stream thus may be understood to have upstream and downstream ends.

#The water in the inlet connection 105 is provided at a standard pressure for a hydro-therapy spa. The inlet connection provides water into an upstream end 113 on the first nozzle 107. The first nozzle includes a conical inner surface 114 that contracts in diameter in the downstream direction. As the water stream flows into the reception end and through the first nozzle, it accelerates to a greater speed until it reaches a downstream end 115 of the first nozzle.

#The downstream end 115 of the first nozzle 107 directs the accelerated water stream to flow into and through the air inlet chamber 106. The accelerated water stream entrains air from the air inlet chamber as it passes through, and thus becomes aerated. From the air inlet chamber, the aerated, accelerated water stream flows into an upstream end 116 of the second nozzle 108. The second nozzle includes an inner surface 117 having a circular cross-section that expands in diameter in the downstream direction. The increasing diameter decelerates the aerated, accelerated water stream, producing an aerated water stream. The aerated water stream then passes out a downstream end 118 of the second nozzle.