Patent Application
20090094736
The invention relates to whirlpool bathtub jet apparatus of the type wherein one or more jet assemblies are installed in a tub wall.
Whirlpool jets of the type used in spas and bathtubs are used to recirculate water inside the tub or spa, with or without injection of air. For this purpose, the jet assembly is set in a hole in the tub wall and powered by an electric motor that drives an impeller. Recently, “pipeless” jets have become popular wherein the jet draws water into a chamber inside the unit, redirects its flow in a radial or lateral direction, and then ejects it from one or more nozzles, without the use of a pipe that carries water from an inlet to an outlet location on the tub wall. See Jaworski U.S. Pat. No. 4,853,987 and Booth U.S. Pat. Nos. 5,414,878 and 5,587,023. A plastic cover or escutcheon plate covers the mouth of the jet, and in many designs provides openings for the intake opening(s) and outlet nozzle.
The inlet and outlet positions will depend on the type of centrifugal pump being used. In a mixed flow pump, the nozzle is located at or near the center with the intake openings around the outside of the cover plate. In a radial flow pump, the intake is at the center with nozzles on the outside, depending on the arrangement of the impeller and the casing enclosing it.
Most pipeless jets are driven by an electric motor positioned behind the water circulation chamber. The impeller can be driven by a drive shaft that extends through a water tight hole in the back wall of the chamber, as shown in the Booth patents cited above. To avoid the need for a drive shaft that penetrates the plastic pump housing, more recent jet designs provide the impeller with a magnetic rotor that is positioned so that the impeller can be driven directly by the magnetic field created by the electric motor's stator, which field extends through the rear wall of the water chamber.
Known spa jets have also used Hall effect sensors or switches for purposes of allowing a user to control the jet, or to monitor the state of the impeller. See, for example, U.S. Pat. Nos. 5,983,416 and 6,295,662. In a prior art jet assembly sold by Sanijet Corporation known as the 30008, the pump housing was of the mixed-flow type. It included an escutcheon outer pump housing section attached to the inside of the escutcheon, an impeller and an inner pump housing section which fit together with the outer pump housing section. This pump assembly was removed as a unit for cleaning. It proved cumbersome in this device to provide an interlock that would turn the pump motor off when the pump housing had been removed. A magnet was housed in a molded plastic projection on the outer pump housing section, the inner section had a tubular holder on its outside for housing a metal flux pin. When the pump housing sections were secured together, the magnet and flux pin are aligned with each other. When pump assembly was then inserted into the pump casing, the magnet and flux pin aligned with a hall effect sensor positioned behind inner housing section.
The sensor sent a signal indicating when all components were correctly installed, otherwise the pump motor would not run. However, it was not of great utility from a safety standpoint. In such a mixed flow pump where the impeller is enclosed in a housing and is removed at the same time as the cover, there is no danger that the impeller will run when the device has been disassembled. Sensor responsiveness was an issue because the magnet was spaced from the sensor and a flux pin had to be interposed between them. The present invention addresses these and other limitations.
Pipeless jet assemblies can be potentially hazardous in certain situations. If a bather's hair becomes caught in the jet while it is running, the bather could drown. Many jet designs permit the cover to be removed manually for purposes of cleaning. However, injury could result if the cover is removed while the impeller is running. A pipeless jet marketed by Lexor Inc. has a plastic housing that covers the blades from the front of the impeller, so that the blades are only exposed around the side where water is ejected circumferentially. These covered blades also are more difficult to clean. The present invention addresses these drawbacks.
A jet for use in a whirlpool tub or spa according to a first aspect of the invention includes a motor assembly including an electric motor disposed inside a motor housing, which motor housing includes a frontwardly facing, water-tight recess. Suitable means are provided for mounting the motor assembly in a hole in a tub wall, including the 3-piece mounting system set forth in the detail description hereafter, as well as others known in the art, such as using J-latch assemblies as shown in the foregoing Booth patents, or use of external threads on the pump housing and a threaded plastic ring mounted thereon, which is tightened to clamp the jet to the tub wall. A centrifugal pump assembly used in the jet includes a rotor-impeller having a rear, magnetically attractable rotor disposable in the recess of the motor assembly and a front set of blades. A cover having water inlet and outlet openings is removably securable over the rotor-impeller. A sensor system is provided which can be connected to the motor to shut off the motor when the cover is removed from the centrifugal pump assembly. The sensor system includes a sensor target disposed on a rear surface of the cover, and a sensor disposed on or near the pump assembly, such that the sensor detects the sensor target only when the cover is secured over the centrifugal pump assembly in one or more predetermined positions. Known centrifugal pumps used in spa jets lack such a sensor system but have a much more acute need for it than mixed flow pumps wherein the blades are removed at the same time as cover, making it impossible for the user to be injured by the uncovered blades.
According to a further aspect of the invention, two or more sensor targets are provided such that the sensor detects one of the sensor targets only when the cover is secured over the centrifugal pump assembly in two or more predetermined positions. The cover has a plurality of small water inlet openings distributed about its surface, and one or more off-center outlet openings. By repositioning the cover, the user can vary the water flow direction from the outlet opening depending on which predetermined position the cover is secured in. If more than one outlet opening or nozzle is provided in the cover, then this embodiment of the invention requires that these not be placed so symmetrically that changing from one predetermined position to another causes the outlet openings to exchange positions and thereby does not result in any change in water flow in the tub.
The invention further provides an improved system for mounting a motor assembly in a tub wall that uses detents instead of threads. These and other aspects of the invention are further discussed in the detailed description that follows.
In the accompanying drawings, wherein like numerals denote like elements:
Referring to
An interlock sensor 31, preferably a Hall effect switch or sensor, is set in a rearwardly opening socket 32 in case 14 so that its front end is close to the flat front surface of rim 28. A wire 33 ending in a connector 34 extends rearwardly for direction connection to motor 16, or a separate controller 35 for motor 16. Sensor 31 is used to cut power to motor 16 unless the presence of a magnet is detected in front of it as described further below.
Motor assembly 15 comprising case 14, motor 16 and clamp ring 19 is secured in hole 11 by means of a mounting system including a tubular flange bushing 41, gasket 42 and a lock ring 43. Gasket 42 is set behind a front radial rim 44 of bushing 41. Rim 44 has a greater diameter than hole 11, whereby gasket 42 is clamped against the inside of the tub wall 12 when an externally threaded, rear end portion 46 of bushing 41 is inserted fully into hole 11. Lock ring 43 is internally threaded and is threadedly coupled to end portion 46 on the outside of the tub, securing bushing 41, gasket 42 and lock ring 43 to hole 11. The assembly of case 14, motor 16 and ring 19 fit into the front end of bushing 41 into engagement with an inwardly directed lip 45 in front of shoulders 47 of bushing 41.
Referring to
A pump assembly 60 for use with the motor assembly 15 includes a centrifugal rotor-impeller 61, an outer escutcheon or cover 62, and a flow guide insert 63. Rotor-impeller 61 includes a hemispherical steel bowl or shell 64 which houses the rotor magnet 50. Shell 64 fits into concave interior recess 18. As shown in
Cover 62 with flow guide 63 attached as described hereafter is secured over rotor-impeller 61. Flow guide (pump cap) 63 is removably attached to pump case 14. Flow guide 63 has a pair of curved lips 65 on opposite sides that fit though corresponding slots 70 on the inside of rim 28 of pump case 14. Once lips 65 are fully inserted into case 14, flow guide 63 is rotated 90 degrees into a locked position in which lips 65 are behind the inner edge of rim 28, the position shown in
Cover 62 is a one piece plastic disk having an annular rim 73 that fits over the outside of bushing 41. It is rotationally positioned and mounted onto bushing 41 my means of a pair of detent projections 74 located 180° apart on the front face of rim 44 of bushing 41. Rounded, inwardly directed projections 76 on rim 73 releasably engage outwardly facing rounded grooves 77 in projections 74, enabling cover 62 to be hand tightened and removed. The placement of projections 74, 76 permits the cap to be mounted in either of two positions 180° apart, allowing the nozzle clearance opening 78 (provides clearance for 96), which is located off center, to be positioned above center (as shown), below center, or right/left, if bushing 41 is repositioned so that projections 74 are positioned left and right, or additional projections 74 are provided. As a result, in a whirlpool tub or spa according to the invention, jets can be placed in pairs on a tub wall 12 with nozzles in closer or further apart positions, as shown in
Cover 62 further has intake holes 79 distributed around its surface. Holes 79 are preferably small and spaced apart over an outer annular portion of cover 62 to avoid user hair entrapment than can result when strong suction is created over a small area of the jet. There is also a small outer radial suction gap 90 (
One post 81A corresponds to the nozzle position shown in the drawings, whereas the opposing post 81B aligns with sensor 31 when the nozzle opening 78 is placed in its alternative position as discussed above. By providing multiple magnets in this manner, the jet assembly can be made operable in two or more predetermined positions of cover 62 (and guide 63) relative to the rest of the jet assembly. For additional safety, it is preferred that sensor 31 be a unipolar Hall effect sensor, such that placing the cap on backwards will not allow the motor 16 to run, even if a magnet 82 is close to sensor 31.
Cover 62 snaps onto pump cap 63 which provides jar lid type handle for inserting pump cap and rotational lock of pump cap into pump case. It also prevents a user from touching the spinning blades 71 at pump caps suction opening 94. One of it's most important functions is to provide a large outer annular surface area for multiple small suction openings whose total area is greater than suction opening 94 below.
Flow guide 63 is a plastic insert in the shape of a two sided cup having a cylindrical outer wall 86 from the front of which a pair of opposed, undercut tabs 87 project. Tabs 87 resiliently engage complementary shaped grooves 88 in a pair of projections 89 formed in the inside of cover 62, inwardly from the intake holes 79. The user can squeeze tabs 87 in order to remove guide 63 for cleaning after cover 62 has been removed. Posts 81 have rails 80 thereon which slide into corresponding grooves 85 in flow guide 63 so that tabs 87 are in alignment with projections 89.
A bottom wall 91 of guide 63 is located in between the front and rear edges of outer wall 86, dividing guide 63 into a front flow chamber 92 and a back flow chamber 93. Chambers 92, 93 are in communication by means of a central hole 94 at the center of bottom wall 91, which hole is positioned directly over the center of rotor-impeller 61. Water flowing in the direction of the arrows in
Flow guide 63 is configured to guide water entering through holes 79 in cover 62 to the center of the device while minimizing pressure drop, and then allow it to flow out through the nozzle (tube 96) without any internal countercurrent flow between water entering the jet and water exiting the jet. When cover 62 and guide 63 are removed together, rotor-impeller 61 may then be manually removed for cleaning. Unlike a known design wherein the frame of the rotor-impeller includes a front enclosure that conceals the blades, the rotor-impeller 61 with exposed blades 71 can be cleaned more easily and thoroughly. However, since blades 71 are difficult to grasp, roller-impeller preferably has a central knob 100 that can be grasped by the user once cover 62 is removed. Since the blades 71 are exposed, it is especially important that motor 16 be cut off by sensor 31 when cover 62 is not in place.
It will also be noted from the foregoing that the user removes cover 62 by twisting it, which twisting can be in the same direction as the twisting action that would disengage the motor assembly 15 from flange bushing 41. To prevent this from happening, the force required to disengage the motor assembly 15 from its detents is considerably greater than the force needed to unlock cover 62, and may require use of a tool such as a spanner set in a pair of opposed notches 105 on the inside of rim 28 of case 14. The whirlpool jet as described herein can thus be partially taken apart for cleaning, or removed and replaced in its entirely if for example the motor fails, without need to access components on the outside of the tub wall, which is often covered by a tub skirt, wall, or the like.
Lock ring 43 in the preceding embodiment may be an ordinary threaded plastic ring comprising a front flange 101 with a flat surface for engaging the outside of the tub wall, and an internally threaded body 102 which tightens onto threaded end portion 46. As shown, ring 43 is further improved by providing a set of radially spaced arms 103 formed by radial cuts 104 part way through the width of flange 101. The insides of arms 103 have rounded projections 106 thereon which engage the outside of the tub wall 12 as shown in
The foregoing embodiment is the presently preferred embodiment of the claimed invention. It will be readily apparent to one skilled in the art that many variations of the invention can be made without deviating from the scope of the claims. For example, the Hall effect sensor may be replaced by one or more light sensors, and the magnets by reflectors, with transparent plastic used where needed to allow light transmission. This and other modifications are considered within the scope of the appended claims.
