Porous solenoid structure

A spa water delivery system comprising a reciprocating pumping structure to pump water for reception in a spa zone; and driver structure, including a solenoid body element and a solenoid plunger element, the elements being relatively movable; at least one of the elements containing passage structure to receive water in communication with water to be pumped to the zone.

BACKGROUND OF THE INVENTION
 This invention relates generally to improvements in structure and operation
 of hydrotherapy massage jets of the type used in spas and hot tubs, and
 the like. More specifically, it relates to the control of pumping of fluid
 via such jets to the spa or tub interior, and also to regulation of fluid
 flow to and from a self-contained jet fluid pumping unit.
 Spa jets for use in spas, swimming pools, and hot tubs, and the like, are
 generally known in the art to provide a hydrotherapy massage action. In
 particular, conventional spa jets are mounted in the wall of a spa or hot
 tub and coupled by plumbing lines to a water recirculation system,
 including a pump which draws water from the pool or spa and recirculates
 that water to and through one or more spa jets for return flow to the pool
 or spa. The spa jets are designed to produce a pressure jet flow of water,
 which is discharged into the body of water within the pool or spa, often
 by means of a directionally adjustable discharge nozzle. A person within
 the pool or spa can orient himself in a selected position relative to a
 spa jet to receive a vigorous and desirably therapeutic massage action.
 While conventional spa jets of the abovedescribed type are widely used and
 provide a desirable hydrotherapeutic benefit, a relatively complex
 plumbing network is required for water recirculation to the spa jet. This
 plumbing network is normally installed at the time of spa construction by
 positioning the necessary flow conduits directly within the structural
 wall of the spa. This arrangement is relatively complicated and expensive,
 and thus contributes significantly to the overall cost of a spa system. In
 addition, a person using the spa typically has little or no control, other
 than directional adjustment over the power of the water jet discharged
 into the spa.
 There is need for improved spa jet unit which can be mounted quickly and
 easily into a spa wall without requiring construction of complex plumbing
 flow conduits; and further, wherein the improved spa jet is adapted for
 relatively simple and adjustable regulation of the power and flow
 characteristics of a discharge water jet.
 There is also need for simple, effective control of a jet-pumping unit, and
 for effective regulation of fluid flow to and from a self-contained fluid
 jet-pumping unit.
 There is additional need for improved structure enabling enhanced heat
 transfer from a solenoid to water being pumped; and/or enabling plunger
 movement with less resistance imposed by water in the path of plunger
 movement; and/or enabling plunger movement with less bearing friction.
 SUMMARY OF THE INVENTION
 It is a major object of the invention to provide a solution to the problems
 and difficulties with prior water jetting systems, as used in spas and hot
 tubs. Basically, the invention concerns provision in a spa unit having
 wall means facing toward or bounding a water reception zone, of:
 a) one or more water pumps associated with the wall means, the pumps spaced
 about the zone, and the pump or pumps oriented to receive water intake
 from the zone and to discharge water streams into the zone,
 b) each pump including water pumping structure, and there being means for
 controlling pumping operation of such structure, as by a bather in the spa
 interior.
 As will be seen, the water-pumping structures may be independently operable
 and are spaced about the zone.
 Another object is to provide:
 a) water delivery structure associated with the wall means to deliver water
 to the zone,
 b) a manually operable signaling device carried by the wall means to be
 operated by a bather in the water reception zone,
 c) a sensor spaced from the signaling device to be out of contact with spa
 water, and responsive to operation of the signaling device to produce a
 control signal,
 d) whereby the control signal may be used to control a flow characteristic
 of water flowing via the delivery structure to the zone.
 Such apparatus provides a means to transmit an input signal to an
 electronic spa or jetted bath control system in a safe, convenient and low
 cost manner. The apparatus allows for a signal (magnetic field) to be
 transmitted through a surface (the housing) to a sensor (Hall Effect or
 reed switch), which controls the pumping means. The end result is the
 bather is able to move an element within the spa or jetted bath, which is
 attached to the water side of the jet housing, and create an electrical
 output signal by a device on the dry side of the housing, thereby safely
 eliminating wet bather contact with any electrical elements.
 A further object is to provide a signaling device which produces a magnetic
 field, the sensor located in that field to be responsive to a changing
 characteristic of the field.
 In one embodiment, the invention comprises a rotating ring, a magnet and a
 linear Hall Effect sensor all located in a hydrotherapy jet housing. The
 Hall Effect sensor responds to varying magnetic fields by producing a
 varying voltage output. An example of such a sensor is the Model 3503
 sensor made by Allegro Microsystems Inc. of Worcester. Mass.
 In this embodiment, the Hall Effect sensor is mounted in the wall of the
 jet housing. A rotating ring with an embedded magnet is typically mounted
 inside the jet housing, so that it is able to rotate freely. The effect of
 rotating the ring is to vary the distance of the magnet to the sensor,
 thereby varying the voltage output signal of the sensor. This signal can
 then be used as a means to signal the electronic controls to vary the
 pulse rate of the pumping unit, as well as to turn it completely off.
 In another embodiment, the linear Hall Effect sensor can be replaced with a
 Hall Effect switch. An example of this would be the Model 3133 from
 Allegro Microsystems Inc. In this embodiment, the control would be able to
 act as an on/off signal to the electronic control system.
 In yet another embodiment, the Hall Effect sensor is replaced with a reed
 switch. The reed switch in its most common form is a device that produces
 a switch closure when in the presence of a magnetic field. An example of
 such a device would be the Model MDSR-7 made by Hamlin Inc. of Lake Mills,
 Wis..
 An additional object is to provide water delivery structure, which includes
 i) porting associated with the wall means and via which water is delivered
 to the zone,
 ii) water pumping structure controlled by the sensor to deliver water to
 the porting.
 As will appear, the water delivery structure typically includes at least
 one pump structure oriented to receive water intake from the zone and to
 direct water into the zone, the pumping structure controlled by the
 control signal. The pumping structure typically includes a chamber having
 a water inlet and outlet, and a water displacing reciprocating element
 operable to draw water into the chamber via the inlet and to discharge
 water to flow from the chamber through the outlet to the spa interior
 zone, water also flowing to the side of the element opposite the chamber.
 Yet another object is to provide a diffuser in alignment with the water
 delivery structure, and adjustable to control a characteristic of the
 water flow.
 An additional object is to provide a spa water delivery system that
 comprises:
 a) reciprocating pumping structure to pump water for reception in a spa
 zone,
 b) and driver structure, including a solenoid body element and a solenoid
 plunger element, the elements being relatively movable,
 c) at least one of the elements containing passage structure to receive
 water in communication with water to be pumped to the zone.
 A yet further object is to provide driver structure that includes solenoid
 electrical winding structure, the passage structure extending in
 relatively close relation to the winding structure, whereby cooling liquid
 or fluid may flow reversely in cooling relation to the winding structure.
 In this regard, the winding structure may have at least three sides, and
 said passage structure extends adjacent at least two of said sides.
 An additional object is to provide a solenoid body element having a wall
 through which a portion of said passage structure extends, to communicate
 with opposite ends of the solenoid. Further, solenoid body and plunger
 elements preferably have relatively movable walls defining a variable
 volume chamber into which fluid is received and from which fluid is
 expelled, during reciprocating operation of the solenoid.
 Another object is to provide fluid cooled solenoid apparatus that includes:
 a) reciprocating pumping structure to pump fluid,
 b) and driver structure for said pumping structure, including a solenoid
 body element and a solenoid plunger element, said elements being
 relatively movable,
 c) at least one of said elements containing passage structure to receive
 fluid flow in opposite directions during operation of said pumping
 structure.
 These and other objects and advantages of the invention, as well as the
 details of an illustrative embodiment, will be more fully understood from
 the following specification and drawings, in which:

DETAILED DESCRIPTION
 Referring first to FIGS. 12 and 13, a spa 200, includes wall means, as at
 201, facing toward a water reception zone 202. The wall means may include
 a synthetic resinous wall 201a bounding zone 202. The inner face of the
 wall means appears at 201b.
 A plurality of water pumps are associated with the wall means, the pumps
 indicated generally at 203, and as spaced about zone 202. If desired, only
 one pump may be employed, and any number of pumps may be used. The pump or
 pumps are oriented to individually receive water intake from zone 202 at
 intake port or ports 204, and to discharge water streams 205 into zone
 202, as via discharge ports. Such ports are defined by nozzle or nozzles
 206.
 Water pumping structure is indicated by block 207, in the pump 203 seen in
 FIG. 13. Note pump housing 203a received in the recess 208, formed in the
 wall 201a. It may be retained in position frictionally, or by other means.
 The water pumps are preferably independently operable, as by drive means
 associated with each pump and located at the pump. Also, the pumps may be
 operated to vary the rate of pumping action, and the stroke of the pumping
 element, i.e., variable as to amplitude and frequency of pumping action,
 to vary the jets 205 to best use of the bather. In this regard, while the
 pumps are herein described as operating by reciprocation, it is possible
 to provide rotary impeller-type pumps having controllably variable
 impeller rates of rotation, and so long as the jets 205 are directed
 toward the interior region of the spa, as indicated.
 Control means to control the pumping structure is indicated generally at
 210 in FIG. 12. Note the three cables 211a, 211b, and 211c extending
 respectively to the drivers at the three pumping structures 203 shown for
 independent control. Note the frequency and amplitude controls 210a and
 210aa controlling one pump via cable 211a; frequency and amplitude
 controls 210b and 210bb controlling a second pump via cable 211b; and
 frequency and amplitude controls 210c and 210cc controlling a third pump
 via cable 211c. ON-OFF switches may be provided in or proximate of the
 controls 210a, 210aa, 210b, 210bb, 210c, and 210cc, for further selective
 control, in various combinations of amplitude and frequency of pumping
 action at different pumps. A spa liner may be employed, as at 212, and
 clamped by a pump flange 225.
 As a result, a minimum of pumping structure is provided; no water liner or
 ducts in wall 201 are needed; the pumps are individually and independently
 operable and controllable.
 In the exemplary drawings 1-11, an electrically powered spa jet unit,
 referred to generally in FIG. 1 by the reference numeral 10, is provided
 for use in a spa 12 or the like, to deliver a discharge jet of water to
 provide a hydrotherapy massage action. The spa jet unit 10 is typically
 installed in a side wall 14 of the spa in several selected locations about
 the spa perimeter and below the normal water fill line. Each jet unit 10
 represents a relatively compact and substantially self-contained unit,
 which can be individually controlled by an appropriate control unit 16,
 all without requiring complex plumbing flow conduit networks and related
 recirculation pump devices.
 In general terms, the spa jet unit 10 of the present invention includes an
 electrically powered reciprocal element 18 adapted for regulation by the
 control unit 16 to deliver a pulsating jet of water through a discharge
 nozzle 20. Each jet unit 10 is adapted for mounting into an open-sided
 pocket 22 formed in the side wall 14 of the spa 12, with appropriate
 electrical conductors 24 interconnecting each jet unit 10 to the control
 unit 16. No plumbing conduits or related recirculating equipment is
 required. As a result, the overall hydrotherapy massage system is
 relatively simple and economical.
 The spa jet unit 10 is shown in one preferred form in more detail in FIGS.
 2-5. As shown, the jet unit 20 comprises a generally cup-shaped outer
 housing 26 adapted for slide-fit reception into the side wall pocket 22,
 with the reciprocal element 18 comprising a solenoid mounted on a base
 wall 27 of the housing 26. The solenoid 18 includes a reciprocal plunger
 28 having a free end contacting and preferably connected to a central
 region of a resilient diaphragm 30 formed from a suitable elastomeric
 material. An outer rim of the diaphragm 30 is trapped or retained against
 the periphery of the housing base wall 27 by a retainer sleeve 32 mounted
 within the outer housing 26, as by means of a threaded interconnection
 therebetween.
 A port sleeve 34 is mounted in turn within the retainer sleeve 32, as by a
 further threaded connection therebetween. The port sleeve 34 defines a
 port wall 36, which extends across the interior of the spa jet unit in a
 position spaced forwardly from a normal, unstressed position of the
 diaphragm 30. Thus, the port sleeve 34 cooperates with the diaphragm 30 to
 define a pump chamber 38 for the spa jet unit.
 A plurality of intake ports 40 are formed in the port wall 36 in a circular
 pattern about the centrally positioned discharge nozzle 20, which is also
 formed in the port wall 36. Importantly, the rear or inboard sides of the
 intake ports 40 are normally covered by resilient valve flaps 42, which
 are retained between an inboard end of the port sleeve 34 and a short
 flange 44 formed on the retainer sleeve 32.
 As shown in FIGS. 4 and 5, reciprocal operation of the solenoid 18 is
 effective to draw water from the spa into the pump chamber 38 (FIG. 5),
 and then to discharge that water as the pressure discharge jet through the
 nozzle 20 (FIG. 4). More particularly, as shown in FIG. 4, movement of the
 solenoid plunger 28 through an advance stroke depicted by arrow 46 expels
 water from the pump chamber 38 in the form of a discharge jet passing
 outwardly through the nozzle 20. During this stroke movement, the water
 pressure within the chamber 38 effectively retains the valve flaps 42 in a
 closed position, thereby confining water discharge to passage through the
 nozzle 20. Subsequent movement of the plunger 28 through a retraction
 stroke, as depicted by arrow 47 in FIG. 5, causes the diaphragm 30 to flex
 rearwardly, resulting in a momentary vacuum within the chamber 38, whereby
 water is drawn from the spa into the pump chamber 38 through the intake
 ports 40, as well as via the nozzle 20. FIG. 5 shows pressure-caused
 retraction of the valve flaps 42 to accommodate relatively free inflow of
 water through intake ports 40 into the pump chamber 38.
 The control unit 16 (FIG. 1) includes appropriate controller components for
 regulating the operation of the solenoid 18 in a manner achieving
 adjustable discharge jet power and pulse rate. For example, a pulse width
 modulator with frequency control may be used for regulating the
 reciprocating frequency and/or stroke length of the solenoid 18, according
 to the preferences of an individual using the spa. Alternately, pulse
 width modulation systems may be employed to achieve a range of power and
 frequency selection, which can be programmed through variable speed
 frequencies. The control unit 16 may be used for common control of
 multiple spa jet units 10, or otherwise adapted to individually control
 each spa jet unit.
 FIG. 6 illustrates one alternative form of the invention wherein components
 identical to those shown and described in FIGS. 1-5 are referred to by
 common reference numerals. FIG. 6 differs from the embodiment of FIGS. 1-5
 in that a small flow of water is employed to cool the solenoid 18, thereby
 preventing overheating thereof during operation. As shown, this small
 water flow is obtained by providing a small circulation tube 48 with an
 inlet end tapped into the pump chamber 38. The circulation tubing 48
 includes a coil segment 49 wrapped about the winding portion of the
 solenoid 18 in heat transfer relation therewith, and then extends to a
 discharge end connected to the region in front of the port wall 36. During
 reciprocal solenoid operation, a small portion of the water under pressure
 within the pump chamber 38 is forced to flow through the circulation
 conduit 48 to cool the solenoid.
 FIG. 7 shows another alternative form of the invention wherein a modified
 reciprocal element 118 is provided in lieu of the solenoid device shown in
 FIGS. 1-6. In this version, an electric motor 50 is mounted on the base
 wall 27 of the outer housing 26, and includes a rotary output shaft 52
 connected by a pair of crank links 54 and 55 to a head 56 coupled to the
 diaphragm 30, in the same manner as previously described with respect to
 the solenoid plunger 28. Operation of the motor 50 displaces the crank
 links 55 and 55 in a manner providing the desirable reciprocal action of
 the diaphragm 30, as previously described.
 FIG. 8 shows a further alternative form of the invention, generally in
 accordance with FIGS. 1-5, except for the inclusion of an air induction
 system 58. The structural components shown in FIG. 8 are otherwise
 identical to those shown and described in FIGS. 1-5, and are thus
 identified by common reference numerals. The air induction system 58
 comprises an air induction tube 60 having one end coupled to ambient air,
 and an opposite end tapped into the pump chamber 38. A one way check valve
 62 is mounted along the air tube 60 to permit air inflow to the pump
 chamber 38, while preventing water backflow through the air tube. A
 control valve 64 may be provided to regulate air flow through the air tube
 60.
 During operation, and upon retraction motion of the diaphragm 30 to draw
 water into the pump chamber 38, the momentary vacuum in the pump chamber
 38 additionally draws air therein via the air tube 60. As a result, a
 quantity of air is entrained with the water within the pump chamber 38,
 for discharge with the water as an air-water jet during subsequent advance
 stroke motion of the diaphragm 30. The combined air-water jet is known to
 provide an enhanced therapeutic massage action.
 FIG. 9 illustrates an alternative air induction system 158 wherein the back
 or inboard side of the diaphragm 30 cooperates with the housing base wall
 27 to define an air chamber 66 for pumping air into the spa jet unit. In
 this version, an air tube 160 with a check valve 162 therein is provided
 for drawing air into the air chamber 66 each time the diaphragm 30 is
 displaced forwardly by the solenoid 18. Subsequent retraction of the
 diaphragm 30 is effective to expel air from the chamber 66 through a tube
 segment 68 and associated check valve 70 for passage into the pump chamber
 38 and entrainment with water therein. A bleed tube 72 may be connected
 into the tube segment 68, and equipped with an adjustable valve 74 for
 regulating the amount of air injected into the pump chamber 38. Air
 injected into the pump chamber is, of course, expelled with the water as a
 combined air-water jet through the forward nozzle 20.
 FIGS. 10 and 11 show still another alternative embodiment of the invention
 wherein components corresponding in structure and function to those shown
 and described in FIGS. 1-5 are identified by common reference numerals. In
 this embodiment, a cup-shaped outer housing 26 has a solenoid 18 carried
 by a base wall 27 thereof, with a reciprocal plunger 28 coupled to a
 pumping piston 75. The piston 75 comprises a circular plate having an
 annular array of pump ports 76 formed therein, with the outboard side of
 the ports 76 being normally covered by a resilient flap valve 78, the
 center of which is secured in a suitable manner to the pump piston 75. The
 piston 75 is reciprocally carried within a cylinder 80 and cooperates with
 a front wall 81 of the cylinder 80 to define the pump chamber 38. The pump
 chamber is open to the body of water within the spa through a forward
 discharge nozzle 20, which may include a narrow central jet port 82.
 As shown, the outboard side of the spa jet unit includes a perforated cover
 plate 84, which cooperates with the nozzle 20 to retain an angularly
 adjustable nozzle fitting 86. An air induction tube 88 is coupled to the
 interior of the nozzle 20, at the downstream side of the jet 82, to permit
 entrainment of air therein in response to water pumping through the nozzle
 20.
 Advancement of the solenoid plunger 28 displaces the pump piston 75 in a
 forward direction within the pump chamber 38, to displace water therein as
 a discharge jet outwardly through the nozzle 20 and associated nozzle
 fitting 86. During this discharge step, the flap valve 78 sealingly
 overlies the piston ports 76, so that the water in the pump chamber 38 is
 forced outwardly into the spa (FIG. 10). While a peripheral seal may be
 provided between the pump piston 75 and the inner diameter of the cylinder
 80, a small clearance between these elements will normally suffice to
 provide the desired pumping function.
 Subsequent retraction of the solenoid plunger 28 draws the piston 75
 rearwardly within the cylinder 80. In this regard, the inboard side of the
 pump piston 75 and the cylinder 80 is in open flow communication with the
 perforated coverplate 84, around the periphery of the cylinder 80, so that
 water behind the piston 75 is allowed to displace forwardly through the
 pump ports 76 into the pump chamber 38. The flap valve 78 flexes forwardly
 (FIG. 11) as the piston is drawn rearwardly by the plunger 28, to allow
 the water to flow through the pump piston 75. Accordingly, reciprocal
 driving of the piston 75 within the cylinder 80 affectively discharges a
 water jet through the nozzle 20 and nozzle fitting 86, in a pulsating
 fashion, to provide a desirable therapeutic massage action.
 FIG. 10 also shows the pump unit in discharge motion, the flow channels 89
 having water flowing in an inwardly direction, as marked by the arrows and
 toward chamber 189 rearwardly of the reciprocating elements 75 and 78.
 This flow is in opposite direction to the flow through the central jet
 port 82, as marked by the arrow. With proper design, these flows are
 balanced to cancel or reduce momentum forces transmitted to the spa or tub
 wall.
 Referring to FIG. 11, it shows the pump unit in retraction motion. Flap
 seal 78 opens to allow free fluid movement through the reciprocating
 element. No substantial fluid movement is produced through central jet
 port 82 or through flow channels 89.
 FIG. 14 shows an embodiment wherein the reciprocating element 220 drives
 end wall 221a of a bellows 221 in reciprocation, to draw fluid into
 chamber 222 via ports 223 and passage 224, and to discharge fluid through
 passage 224. The bellows also provides a seal connection to chamber wall
 225, to seal off and protect the solenoid 226 from the water. A return
 spring is used at 227.
 In devices as described, the housing may consist of a material which
 readily transmits heat causing a thermal connection between the solenoid
 and water in order to cool the solenoid.
 A variety of further modifications and improvements to the spa jet unit of
 the present invention will be apparent to persons skilled in the art.
 Accordingly, no limitation on the invention is intended by way of the
 foregoing description and accompanying drawings, except as set forth in
 the appended claims.
 Referring now to FIGS. 15 and 16, the structure shown is somewhat similar
 to FIGS. 10 and 11. The upright wall of the spa or tub 300 is indicated at
 301, and may consist of synthetic resinous material. A cup-shaped outer
 housing 302 may also consist of synthetic resinous material. It is set or
 received into a recess 303 formed in wall 301 opening toward the
 water-filled spa interior zone 304. Housing flange 302a fits against the
 wall inner side 301a.
 Water delivery structure is received into the housing to deliver water into
 zone 304. Such structure, in the example, includes a driver 306, for
 reciprocating a plunger 307 in the directions indicated by arrows 308. A
 pumping piston 309 is coupled to the plunger and may comprise a circular
 plate.
 The piston defines a water-displacing reciprocating element operable to
 move rightwardly in FIG. 15, to draw water into an inner chamber 311 at
 the front side of the plunger, as via a water flow inlet/outlet hole 312
 in a chamber front wall 313. The periphery of the plate extends adjacent
 and reciprocates adjacent the fixed chamber skirt 311a. As the piston or
 plate 309 moves leftwardly, it displaces water from chamber 311 through
 the hole 312 toward and into the spa interior.
 Water also flows to the rear side 311a' of the piston 309, as via an outer
 passage 317 extending outwardly of and about the inner chamber 311, i.e.,
 it fills the space 314 between the driver 306 and the piston 309, serving
 to at least partly balance the water masses being moved by the piston as
 it reciprocates. This reduces vibration transmitted to the spa wall 301.
 A front plate 315 extends forwardly of wall 313, to define a water flow
 passage 318 communicating between passage 317 and the inlet/outlet hole
 312. Plate 315 carries a diffuser 320 having a forwardly tapering conical
 wall, and in axial alignment with hole 312. Plate 315 has a skirt 315a
 attached as via threading 322 to the housing 302, and a bezel 315b
 overlying flange 302a.
 A permanent magnet 325 is carried by a rotatable ring 326 received into the
 front plate and skirt recess 327, and can be finger gripped by the bather
 in the tub or spa water to adjustably rotate the ring and magnet, and
 relative to a sensor 328. The sensor is shown as isolated from the water
 into the spa, by virtue of its spacing from the water-receiving zone or
 zones, as shown. For example, the sensor can be embedded in the housing
 302, radially outwardly of the path of rotation of the magnet. As the
 magnet is rotated, its magnetic field projected outwardly toward the
 sensor is detected with varying strength as a function of magnet rotation.
 Accordingly, the output signal developed by the sensor has correspondingly
 varying amplitude, or other parameter.
 A connection is shown at 330 from the sensor to the driver, and may, for
 example, vary the pushing output of the driver to vary the pumping effect
 of the piston, thereby varying the water jet output from the hole or jet
 opening 312 to the spa interior, as via the diffuser. A magnetic sensor,
 or a Hall Effect sensor, may, for example, be employed, as previously
 discussed.
 FIGS. 23 and 24 show the forward and rearward water flow characteristics
 when a diffuser is used; whereas, FIGS. 21 and 22 show such flow
 characteristics when a diffuser is not utilized.
 FIGS. 17 and 18 show the same structure as in FIGS. 15 and 16, except for
 the use of multiple sensors in the form of a series of reed switches 340,
 spaced apart circularly about the axis of the adjustable carrier ring 326.
 The magnetically sensitive reed switches are connected at 341 to the drive
 control, so that as rotation of the magnet 325 causes different ones of
 the switches to close, the output pulse rate of the drive can be stepwise
 varied. One or more such reed switches can be used.
 FIG. 21 shows the tendency for the outward flow to maintain a confined "jet
 stream" perpendicular to the hole.
 FIG. 22 shows the flow pattern of a liquid flowing into a hole D. The
 direction of the fluid flow is mainly hemispherical, not streamlike as in
 FIG. 21.
 In FIG. 23, a diffuser A has been placed above the hole and in axial
 alignment with the hole. The jet stream, as it passes through the
 diffuser, entrains fluid, which flows in through openings B between the
 diffuser base and plate 313, and then flows through opening C. The net
 effect is to increase the overall volume of fluid in the jet stream, but
 also to reduce its velocity. This dampens the maximum pressure pulse,
 resulting in a softer feel of water impinging on the bather's skin.
 In FIG. 24, fluid flow is shown passing reversely through 312, at the hole
 D. Fluid motion up through the diffuser persists, although diminished. The
 result is continuous flow through diffuser opening C, even during the
 inward flow period.
 The result of placing the diffuser over a hole or nozzle with an
 alternating inward/outward flow is to soften the pulsating effect and give
 somewhat of a continuous flow pleasing to the bather.
 FIGS. 19 and 20 show an actual application of the diffuser to the nozzle of
 the structure shown. In this case, the diffuser 420 is made to be axially
 adjustable by threaded connection at 350 between diffuser annular inner
 portion 420b and the tapered tubular portion 320 of plate 313.
 In the full open position seen in FIG. 19, water is entrained in through
 the diffuser as discussed above, in regard to FIG. 23. In FIG. 20, the
 diffuser is adjusted to the right to be in the closed position, so that
 there is no opening to allow water entrainment into the jet stream. In the
 closed position, it has no effect on the jet stream. By turning the
 diffuser, the bather is able to increase or decrease the size of the
 opening between the diffuser and the nozzle plate, which reduces to
 varying the variations in velocity and pressure amounts over a pulse
 cycle, and reduces the peak velocity and peak pressure.
 The control devices of FIGS. 15-20 can be employed with any of the pumping
 devices shown in the various drawings.
 The device of FIGS. 15 and 16, and equivalents, may be considered as
 preferred.
 Referring now to FIGS. 25-29, a porous solenoid assembly is shown at 400.
 It includes a solenoid body element 401 and a solenoid plunger element
 402, these elements being relatively movable in an axial direction 403.
 These elements may typically be received within or by a casing indicated
 at 404, within which water 405 is received, so that the plunger element
 reciprocates axially within the water filling the cavity 406.
 The reciprocating pumping structure is indicated at 407, to pump water for
 reception within a zone 408, as within a spa tub. Water is delivered in
 direction 409 into the tub interior 408, in response to operation of the
 pumping structure 407.
 At least one of the elements 401 and 402 contains passage structure, to
 receive water in communication with water to be pumped to zone 408. In
 addition, the cavity 406 receives water that is to be pumped to zone 408.
 In the example shown, the plunger element 402 has a wall 410 through which
 a portion of the passage structure extends, typically to communicate with
 opposite ends of the plunger. As shown, the passage structure includes
 multiple passages 411, i.e., vent holes, which are spaced about axis 403,
 as shown in FIG. 26. Also as shown, the wall 410 may advantageously be
 conical, to interfit conical wall 410a carried by the body element 401.
 The passages 411 define a total area, which is at least about 1/10th the
 total conical wall area. As the plunger reciprocates, water trapped
 between walls 410 and 410a is expelled through the passages 411 toward the
 pumping structure 407, which in turn pumps the water to zone 408.
 Structure 407 is connected at 413 to a shaft 414 carried by the plunger,
 whereby the plunger reciprocates the pumping structure. The solenoid
 elements 401 and 402 may themselves constitute reciprocating pump
 structure, to pump water to zone 408.
 Solenoid wiring 416 may be carried by the body element 401, to receive
 pulsed D.C. current producing the intermittent magnetic field, which
 co-acts with the plunger and spring similar to spring shown in FIG. 37,
 and marked 590 to effect its reciprocation, as plunger element moves away
 from body element 401, as shown in FIGS. 25 and 26. The bearing 420,
 carried by the tubular body element 401, receives the shaft 414, for
 guiding its reciprocation.
 As the plunger element moves rapidly in FIG. 26, water flows into the space
 422, between walls 410 and 410a, by flowing through passages 411. Such
 flow through is indicated by arrows 423; and when the plunger wall 410
 moves toward wall 410a, such trapped water is expelled through the
 passages 411. The cylindrical surface 424 of the plunger loosely interfits
 the cylindrical bore 425 of the body element 401.
 Axially directed passages 426 through the body receive and pass water from
 the interior of cavity 406, for cooling the body of the solenoid. That
 body includes an end plate 401a and annular structure 427 containing the
 wiring 416. Multiple, concentric rows of passages 426 and 426a may be
 formed in the body structure 427, as seen in FIG. 29, those passages
 extending between opposite ends of the body. Accordingly, water in the
 passages 426 and 426a serves to cool the solenoid body by heat transfer.
 Water may be pumped through said passages to enhance heat transfer
 properties.
 Referring to FIGS. 30, 31, 32, 33, and 34, the bearing 420 may consist of
 plastic having a thin, cylindrical wall 430, with flanges 431 and 432 at
 its opposite ends. The wall also may contain an axially extending split or
 splits 433. Accordingly, the wall portions 430a, adjacent the split or
 splits, may be compressed, as shown in FIG. 34, to allow the bearing to be
 received axially into a bore 440 formed by the solenoid body or plunger
 502 as shown in FIGS. 37 and 38. Upon completion of such insertion, the
 flange sections at 431 expand or "snap" outwardly, to overlap the end wall
 442 of the solenoid body or said plunger; and the flange 432 overlaps the
 end wall 443 of the body.
 The plastic bearing is thereby held in position, as seen in FIGS. 25, 30,
 36, 37 and 38. Insertion of the shaft 414 into the bearing bore holds the
 bearing in place, radially, and also during endwise reciprocation of the
 shaft in the bearing.
 FIG. 35 shows the multiple bore configuration in a wall 450, which may, for
 example, take the place of wall 315 in FIG. 15. Wall 450 contains a
 central group of jet ports 451 from which liquid, such as water, is
 discharged toward the spa zone 304, by flowing from space 314 through
 passages 317 and 318 upon movement of the pumping structure or diaphragm
 toward driver 306. During that same stroke water flows through backflow
 ports 452 in wall 450 to inner chamber 311 via port 312. Upon retraction
 of the pumping structure or diaphragm, water flows through backflow ports
 452 in wall 450 to the rear side of that wall. Ports 452 may be arcuate to
 extend around the axis 453. Accordingly, multiple backflow ports and
 multiple jet ports are provided in such a way as to smooth the
 reciprocating operation of the pumping structure, including the solenoid
 driver.
 In summary, applicant has provided effectively large holes in the conical
 section of the plunger. These allow water to escape the cavity, so as not
 to hinder the reciprocating motion of the plunger. Although solenoids have
 previously been made with a simple, small hole to allow air to escape, the
 size and number of holes provided in the FIG. 26 plunger is surprising, in
 that such holes do not greatly diminish the flux path, and thereby do not
 reduce the performance of the solenoid.
 The use of plastic bearings as disclosed in solenoids is also highly
 unusual. Standard bearings are typically made of metal, such as oil
 impregnated bronze (oilite), to simply press fit into a hole. Bronze and
 like metals used for bearing materials will not last in spa and bathtub
 corrosive water environments. Bearing plastics are difficult to use in
 such application, because they are too pliable to hold a press fit, while
 two plastic tubes may be used in plastic bearings, i.e., a harder press
 fittable plastic outer tube, and an inner bearing material tube. This
 configuration unfortunately makes the bearing relatively large in
 diameter. The present solution is to use mechanical means to "snap" the
 bearing into place using only the bearing material plastic, thereby
 allowing a reduced bearing overall diameter and eliminates need for inner
 and outer tubes.
 Referring now to FIG. 36, it shows another modified porous solenoid
 assembly 500. It includes a solenoid body element 501 and a solenoid
 plunger element 502, one of these elements being movable relative to the
 other in an axial direction 503. These elements are received by a casing
 indicated at 504, within which water 505 is received, so that the plunger
 element may typically reciprocate within the water filled or receiving
 cavity 506.
 Reciprocating pumping structure 507 including plate 507a pumps water for
 reception in a zone 508, as within a spa tub. The wall of the tub is
 indicated at 550, forming a recess 551 within which casing 504 is
 removably received. During portion of cycle in which pumping structure 507
 is moving rightwardly, water is delivered as via porting 504a in the
 casing, in direction 509 into the tub interior 508, in response to
 reciprocation of the pumping structure. Water from zone 508 is delivered
 via port 312 to chamber 311. During portion of cycle in which pumping
 structure 507 is moving leftwardly as in FIG. 36 water is delivered from
 zone 508 via porting 504a through passage 574 to cavity 506. Also during
 this portion of the cycle water is delivered to zone 508 via portion 312
 from chamber 311. From the above discussion water is shown to be flowing
 during all portions of the cycle simultaneously inwardly and outwardly of
 the massage jet. This simultaneous flow acts to reduce or eliminate forces
 on the massage jet support structure or wall.
 At least one of the elements 501 and 502 contains passage structure, to
 receive water in communication with water to be pumped to zone 508. In
 addition, cavity 506 receives water that is to be pumped to zone 508.
 The solenoid body element 501 has an end wall 501a with a port or ports 580
 through which a portion of the passage structure extends, typically to
 communicate with opposite ends 560 and 561 of the solenoid annular winding
 562, which is insulated against direct contact with the cooling water. The
 solenoid body has additional common walls 563 and 564. The periphery of
 wall 501a fits in casing annular groove 566, whereby the casing carries
 the solenoid body. See retention flange 563a on wall 563.
 The solenoid plunger element 502 includes an annular plunger body 502a
 which is cylindrical and has a portion closely received within bores 567
 and 568 formed by 562 and 501a. A compression spring 590 extends about
 body 502a and between walls 501a and 507a, urging pumping wall 507a in a
 leftward direction, away from wall 501a. A fixed flow direction wall 570
 is carried by the casing to have a portion 570a extending normal to axis
 571, and a cylindrical portion 570b that extends about pumping wall 507a.
 Cooling of the coil 562 is accomplished by solenoid reciprocation, which
 induces water flow through cooling spaces 592-594 about coil 562. The said
 solenoid reciprocation is accomplished by the alternation direction of the
 net force exerted on the plunger body 502a by the intermittent attractive
 force produced by the intermittent excitation of coil 562 and the return
 force produced by spring 590. During the magnetic attraction portion of
 the cycle, in which the plunger moves in a rightward direction per FIG.
 36, water is forced from cavity 522 through cooling spaces 592-594 through
 passages 580 to cavity 505. During the spring return portion of the cycle,
 in which the plunger moves in a leftward direction per FIG. 36, water
 flows from cavity 506 through passages 580 and through cooling spaces
 592-594 to cavity 522. The cylindrical bore 524 of the plunger carries a
 plastic bearing 596 loosely and guidingly interfitting the surface 525 of
 the guide shaft 595 carried by the solenoid body. A step shoulder 577 on
 the plunger body is engageable with wall 501b to limit the stroke of the
 plunger.
 Accordingly, water flow back and forth in the solenoid recesses to cool the
 solenoid, by heat transfer. FIG. 37 illustrates the water intake stroke of
 the plunger shown in FIG. 36; FIGS. 37 and 38 illustrate the water exhaust
 stroke of the plunger.
 Finally, the porous solenoid, as disclosed herein, has water passages
 through the body of the solenoid. Prior solenoids are limited in power
 density by their relative inability to dissipate sufficient heat.
 Commonly, high-powered solenoids are mounted on large metal plates to
 provide a cooling fin approach to dissipate heat. For underwater
 applications, large amounts of heat can be dissipated directly to the
 water through the body, by provision of water passages inside the solenoid
 body, so as to greatly decrease the distance between the heat-generating
 coils and the water. This technique enables the use of much higher power
 densities, which in turn allows reduction of cost and size of solenoids
 for underwater applications.
 It will also be noted that the fluid cooled solenoid as described has use
 applications other than the application or applications as described
 herein.