Hydrotherapy tub coplanar flow

Information

  • Patent Grant
  • 6760932
  • Patent Number
    6,760,932
  • Date Filed
    Monday, October 22, 2001
    23 years ago
  • Date Issued
    Tuesday, July 13, 2004
    20 years ago
Abstract
Hydrotherapy-tub coplanar-flow device includes slotted nozzle on a body for discharge of fluids from the nozzle in a substantially coplanar flow. The body is adapted for mounting on an inner surface of a hydrotherapy tub and attachable to first and second fluid supply conduits. Further, the body has a first inlet for flow of water from the first fluid supply conduit and a second inlet for flow of air from the second fluid supply conduit. The slotted nozzle discharges these fluids in the substantially coplanar flow. The second inlet of the body is located between the first inlet and the slotted nozzle. The body includes an air dam located between the inlets, such as an interior face portion having a steep decline toward the second inlet of the body.
Description




TECHNICAL FIELD




This invention relates, in general, to hydrotherapy tubs and, in particular, to coplanar flow nozzles usable for creating fluid flow in hydrotherapy tubs.




BACKGROUND ART




Hydrotherapy tubs generally have a number of fluid flow outlets or nozzles. Each flow nozzle usually jets water or a water-air froth into the tub. Enhanced hydrotherapy typically results from strategic positioning of these fluid flow nozzles at various locations in the tub.




One design delivers water to a fixed rectangular spout and subsequently through a wider rectangular outlet for mixing with air and coplanar expulsion along the tub inner surface. An air jacket or shell, extending over the rectangular spout and forming the subsequent outlet, uses the pressure drop caused by the spouted water to draw in the atmospheric air along a path above the water line from a rearward opening within the shell. Such a configuration is disclosed in U.S. Pat. No. 4,953,240 to Gardenier. However, in this coplanar nozzle, there is no separate or isolated conduit for supplying air from underneath the tub surface. Therefore, this type of coplanar-flow nozzle cannot be positioned below the tub water line to produce an air-water mixture or froth. In addition, it remains desirable to provide improvements for the air and/or water flow provided by this type of coplanar-flow nozzle, to enhance the resultant air-water mixture, efficiency, and/or hydrotherapeutic effectiveness.




Thus, a need exists for a hydrotherapy tub and a coplanar nozzle therefor having improved delivery of multiple fluids so that coplanar flow of an air-water froth may occur below the water line. A further need exists for enhanced strategic directioning of the air and water flow paths in providing the air-water mixture or froth. Also, a need exists for a coplanar nozzle forming a water flow path which enhances efficiency and/or effectiveness in drawing air flow to produce a hydrotherapeutic airwater mixture, so that no external pressure source such as a pump is needed to pump air for mixture with water to create a froth.




SUMMARY OF THE INVENTION




The shortcomings of the prior art are overcome and additional advantages are provided through an improved hydrotherapy-tub coplanar-flow device.




The coplanar flow device includes a body having first and second inlets and a slotted outlet or nozzle. The first inlet provides flow of a first fluid, namely water. Further, the second inlet provides flow of a second fluid, namely air. The first and second fluids can be provided from respective first and second fluid supply conduits. The slotted nozzle discharges these fluids in a substantially coplanar flow. The present invention desirably improves hydrotherapy by merging the fluids (e.g., air and water) from the first and second inlets for discharge in the substantially coplanar flow. The second inlet of the body is located between the first inlet and the slotted nozzle. In addition, the body includes an air dam such as an interior face portion having a steep decline toward the second inlet. The steep decline of the interior face portion of the body, is located between the first and second inlets.




In another embodiment of the present invention, the device is mounted on an inner surface of a hydrotherapy tub. Through a slotted nozzle, the fluid is discharged in a substantially coplanar flow on the inner surface of the hydrotherapy tub.




Additional features and advantages are realized through the structures and techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein.











BRIEF DESCRIPTION OF THE DRAWINGS




The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention will be apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which:





FIG. 1

is a side sectional view of one example of a hydrotherapy-tub coplanar-flow device producing substantially coplanar flow in accordance with the principles of the present invention and mounted within a hydrotherapy tub;





FIG. 2

is a top, sectional, cutaway view of another example of a hydrotherapy-tub coplanar-flow device in accordance with the principles of the present invention;





FIG. 3

is a perspective view of one embodiment of a hydrotherapy tub with multiple hydrotherapy-tub coplanar-flow devices, in accordance with the principles of the present invention;





FIG. 4

is an elevation, sectional view of yet another example of a hydrotherapy-tub coplanar-flow device producing substantially coplanar flow in accordance with the principles of the present invention and mounted within a hydrotherapy tub;





FIG. 5

is an exploded view of a number of components of a further example of a hydrotherapy-tub coplanar-flow device in accordance with the principles of the present invention; and





FIG. 6

is a top view of a subset of the components of FIG.


5


.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




In accordance with the principles of the present invention, coplanar flow capability is provided for a hydrotherapy-tub by using a coplanar-flow device in which flow channels merge fluids (e.g., air and water) for discharge from a nozzle in a substantially coplanar flow, as described below.




One example of a hydrotherapy-tub coplanar-flow device incorporating and using the novel features of the present invention is depicted in FIG.


1


and described in detail herein.




In this exemplary embodiment, a coplanar flow device


100


may be mounted onto a hydrotherapy tub


136


so that a slotted outlet or nozzle


102


on body


104


is exposed to the interior of the tub. The coplanar flow device is oriented so that the nozzle allows a water and air mixture (e.g., froth) to flow substantially coplanar from the slotted outlet along an inner surface


134


of the hydrotherapy tub.




Nozzle


102


is in fluid flow communication with flow channels


106


and


108


. Through openings


114


and


116


in the body


104


, inlets


110


and


112


feed fluids (e.g., water and air) from the fluid supply conduits


118


and


120


. For example, water from fluid supply conduit


118


may enter into inlet


110


and flow through flow channel


106


. Further, air from fluid supply conduit


120


may enter into inlet


112


and flow through flow channel


108


. The water in flow channel


106


and air in flow channel


108


are advantageously mixed and ejected out of the nozzle in a coplanar flow


131


(

FIG. 3

) in relative direction


132


over inner surface


134


of hydrotherapy tub


136


.




Preferably, flow channel


106


contains water delivered through fluid supply conduit


118


under pressure. The water flow transition from fluid supply conduit


118


, through inlet


110


, and into flow channel


106


for eventual discharge from nozzle


102


may advantageously serve to promote air delivery from fluid supply conduit


120


and into substantially coplanar flow


131


(FIG.


3


). A decreased cross-sectional area for flow of the pressurized water formed by dam


159


yields increased flow velocity of the water as it passes opening


116


for inlet


112


, which introduces air into body


104


. This increased stream velocity of the water allows air at opening


116


to be drawn through the inlet


112


to form the substantially coplanar flow. In addition, the drawing of air is promoted by a separation distance between the pressurized water, and the opening


116


of the inlet


112


, whose air flow is advantageously influenced and/or promoted by the presence of an air dam which may be formed from a protuberance


159


on interior face portion


163


of body


104


, as described herein. With such a configuration, a sufficient mixture of water and air may be created so that the coplanar flow of the froth is strong enough to provide sufficient hydrotherapy effects, without the use of air pumps for the air.




Further, air may be desirably delivered to body


104


from below the water line. By designing device


100


to increase the water velocity for drawing air through opening


116


, fluid supply conduit


120


may extend below the water line to, for instance, an atmospheric air source having any desired location. For example, the air source could be a valve or hole exposed to the atmosphere from any desired location on hydrotherapy tub


136


, whether above or below a given water line. The valve would allow the user to selectively control the amount of air finally ejected into substantially coplanar flow


131


(FIG.


3


), for improved hydrotherapy.




In one example, the interior face portion


163


of body


104


includes the air dam


159


for enhanced fluid flow, pressure, and/or dynamics, as can be appreciated through examination of

FIGS. 1-3

in conjunction with the description herein. For instance, the air dam


159


may be formed with a protuberance (e.g., a step, stop, and/or other structure which creates a reduction of the cross-sectional area through which flows the water) that may include a steep decline


164


, for example, facing and/or leading toward inlet


112


. The steep decline may comprise an abrupt transition from a land


165


of the protuberance, toward the inlet


112


. For example, the abrupt transition may occur between the land


165


and a region


166


of the interior face portion


163


, with the region


166


located between the protuberance and the inlet


112


. Such a configuration may advantageously cause flow of water from fluid supply conduit


118


, to have a separation distance over the inlet


112


, for example, to promote drawing of air from the inlet


112


to substantially coplanar flow


131


.




As will be understood by those skilled in the art, body


104


with protuberance


159


as an air dam may be configured to cause flow of water from fluid supply conduit


118


to form a low pressure between inlet


112


and the water flowing thereabove from fluid supply


118


. That is, the steep decline


164


may serve to cause the flow of water from the fluid supply conduit


118


to have the separation distance over the second inlet


112


, to form the low pressure over and/or about the second inlet, and/or the region


166


of the interior face portion


163


. This low pressure may advantageously serve as an original and/or added motivation for air to leave a relatively higher pressure in the fluid supply conduit


120


, and enter the flow channel


108


in body


104


. This region


166


and/or protuberance


159


may have any desired size and/or configuration. For example, it may be desirable to increase or decrease the size of the region


166


and/or protuberance


159


, to suit and/or achieve certain flow characteristics and/or mixture composition, such as by increasing and/or decreasing the volume and/or extent between flow channel


106


and inlet


112


(e.g., a section of the flow channel


108


).




Body


104


may be formed, for instance, so that the ratio of the cross-sectional flow area at the water supply inlet


110


to the cross-sectional flow area over the air dam


159


is approximately 1.7 or higher. The cross-sectional area of the inlet


110


may be a passage area (e.g., a circle characterized by an inner diameter) of inlet


110


. The cross-sectional area of the available flow area over the air dam may be defined by the product of the distance from protuberance


159


(e.g., land


165


) to an opposing interior face portion


167


, and the length (e.g., or average length) of sides


105


,


107


(see FIG.


2


). Additional description of

FIG. 2

is presented herein.




One or more benefits, features, advantages, constructions, and/or enhancements analogous to those described herein with reference to protuberance


159


(e.g., for device


100


,

FIGS. 1-3

) may be provided with one or more of protuberances


159


″ (e.g., for device


100


″,

FIG. 4

) and/or


159


′″ (e.g., for device


100


′″, FIGS.


5


-


6


), as will be appreciated by those skilled in the art. Moreover, any appropriate relative location among various components and/or formations (e.g., inlet


110


, inlet


112


, protuberance


159


, and/or nozzle


102


), may be selected and/or formed for a particular device of the invention. Further, a certain device (e.g., devices


100


,


100


″, and/or


100


′″) of the invention may have any number, type, and/or combination of protuberances (e.g., protuberances


159


,

FIGS. 1-3

,


159


″,

FIG. 4

, and/or


159


′″, FIGS.


5


-


6


).




Again referring to

FIG. 1

, in addition to steep decline


164


, protuberance


159


may include an abrupt step or steep transition (e.g., incline)


168


from a region


169


to land


165


of the protuberance. That is, the steep transition


168


and the region


169


may be located between the protuberance


159


and inlet


110


. In guiding and/or directing flow of water from the inlet


110


to have the separation distance over inlet


112


at termination of the protuberance, the steep transition


168


at initiation of the protuberance may, for instance, desirably cause a high pressure over and/or above the region


169


. Various aspects of the invention related to such flow features, system dynamics, and/or hydrodynamics, will be appreciated by those skilled in the art.




Referring still to

FIG. 1

, in one embodiment of device


100


for hydrotherapy tub


136


, water may be pressurized and air may flow from atmosphere pressure so as to be mixed within coplanar flow device


100


for ejection out of nozzle


102


. In another embodiment, both water in fluid supply conduit


118


and also air in fluid supply conduit


120


may be supplied under pressure. Additional description of exemplary air and water flow is presented further below.




For illustrative purposes, the following exemplary dimensions for device


100


are presented. Referring to

FIG. 1

, inlet


110


may have an inner diameter in the approximate range of 13-15 mm. Inlet


112


may have an inner diameter in the approximate range of 4-6 mm. Referring to

FIG. 2

, side


105


of air dam


159


may have a length in the approximate range 20-22 mm. Side


107


of the air dam may have a length in the approximate range 22-24 mm. Sides


109


,


111


may each have a length in the approximate range 6-8 mm. Again referring to

FIG. 1

, body


104


may have a distance from the center of the inlet


110


to steep transition


168


of the air dam, in the approximate range 9-11 mm. The body may have a distance from the center of the inlet


112


to steep decline


164


of the air dam, in the approximate range 4-6 mm.




Referring to

FIG. 1

for explanatory purposes, water is delivered from fluid supply conduit


118


, through inlet


110


, and into flow channel


106


. For water transmission, the fluid supply conduit


118


would be a typical hose or tube leading from a (e.g., 13-14 p.s.i.) pump (not shown) housed within or nearby hydrotherapy tub


136


. The pump would provide sufficient pressure for the formation of coplanar flow


131


(FIG.


3


). For example., the pump may provide a water flow of 13 g.p.m. The pump typically would receive the water from within the tub and recirculate the same into the tub after pumping the water through one or more coplanar-flow devices


100


. Furthermore, the user may advantageously adjust the pressure and/or amount of water delivered through fluid supply conduit


118


, inlet


110


, and flow channel


106


. As will be understood by those skilled in the art, various devices may be used for flow adjustment and controls therefor may appear in various locations.




Air may be delivered from fluid supply conduit


120


, through inlet


112


, and into flow channel


108


. In one example, the air is supplied below the water line yet vented or ducted from an opening to the atmosphere. As described herein, body


104


may be formed so water from inlet


110


and fluid supply conduit


118


, is guided and/or directed by protuberance


159


to flow a separation distance over inlet


112


, and promote and/or enhance drawing of air into the inlet


112


from the fluid supply conduit


120


. This provides an efficient and/or effective system for delivering (e.g., hydrotherapeutically) desirable relative amounts of water and air to the substantially coplanar flow


131


.




For transmission of the air in another example, fluid supply conduit


120


would be a typical hose or tube leading from a compressor or air pump (not shown) housed within or nearby the hydrotherapy tub. The compressor or air pump would contribute adequate pressure to provide desirable characteristics of the substantially coplanar flow. Ambient air vented from an outer surface of the hydrotherapy tub could be fed to the compressor or air pump. As with the water supply line described above, the air supply line desirably may allow the user to adjust the pressure and/or amount of air delivered through fluid supply conduit


120


, inlet


112


, and flow channel


108


.




By allowing the user to adjust the flow characteristics in one or more of the various fluid supply lines as desired in conjunction with the configuration of flow paths in body


104


, the present invention advantageously permits the user to select mixtures and/or delivery rates of fluids such as air and water, for improved hydrotherapy through control over the coplanar fluid flow.




In accordance with the present invention, the hydrotherapy-tub coplanar-flow device may be mounted on the hydrotherapy tub in a variety of ways.

FIG. 1

depicts the body of the coplanar-flow device largely embedded within the hydrotherapy tub wall. In this particular recess, the coplanar-flow device top is entirely covered by the tub inner surface. The nozzle peeks out from under this inner surface to desirably aim along relative direction


132


, approximately parallel to the inner surface.




In a further example, referring to

FIG. 1

, coil clamps


142


may be used to secure fluid supply conduits


118


and


120


to respective inlets


110


and


112


. Also, epoxy and/or glue may be employed.




In particular, inlets


110


and


112


maintain secure fluid communication with respective fluid supply conduits


118


and


120


. For example, each inlet


110


,


112


may possess a number of integrally formed barbs


140


. Upon sliding insertion of each inlet into one of the fluid supply conduits, the barbs provide local points of highly increased static friction. Further, one may tighten clamps


142


around the fluid supply conduits at a location encircling the barbs in order to strengthen attachment of the inlets and fluid supply conduits. These measures yield securely sealed communication of fluid from fluid supply conduit


118


through inlet


110


. Additionally, fluid securely flows from fluid supply conduit


120


through inlet


112


.




Furthermore, coplanar-flow device


100


may include sidewalls


200


surrounding inlets


110


and


112


. For instance, the sidewalls may include exterior threads


202


for mating with nut


204


in order to securely position the device at local inner surface


134


of the tub


136


.




In one example, the device


100


is mounted to the inner surface


134


of hydrotherapy tub


136


using epoxy or a similar water-tight sealant


144


. The epoxy forms a fluid-tight seal that safeguards the contents of the hydrotherapy tub. In one preferred embodiment, the epoxy affixes body


104


in a position over chamber


146


that extends through part of the tub inner surface. The body, epoxy, and chamber cooperate to further provide a safe housing, for the secure fastening of inlets


110


and


112


to respective fluid supply conduits


118


and


120


. The body


104


may be affixed in recess


148


of tub inner surface


134


.




In one embodiment, the various components, layers, or parts of coplanar-flow device


100


are molded of ABS plastic. As one example, any number of parts of the coplanar-flow device may be injection-molded. For instance, any number of the parts of the coplanar-flow device may be unitary and/or integral. In one example, inlets


110


and


112


and/or sidewalls


200


with threads


202


may be unitary and/or integral with body


104


, such as may be done by injection molding. As another example, one may selectively secure the device parts by techniques such as heating or gluing. For instance, layers/plates/portions


154


,


156


,


158


, and


160


could be heated along certain interfaces.




As depicted in

FIG. 3

, a hydrotherapy tub


136


may be equipped with multiple cooperating instances of hydrotherapy-tub coplanar-flow devices (e.g. such as device


100


), in accordance with the present invention. As mentioned above, the slotted outlet or nozzle


102


(

FIG. 1

) advantageously provides substantially coplanar flow


131


relative to the local inner surface


134


. Moreover, the locations of the nozzles participate with local contours of the inner surface to deliver hydrotherapy to the user.




For instance, several of the coplanar-flow devices may be positioned in parallel in order to advantageously provide the coplanar flow


131


in the form of overall sheets of injected fluid. The tub contours already anticipate and promote desirable postures of users in seated and reclined positions. The coplanar-flow devices further promote hydrotherapy by extending the coplanar flow between the tub inner surface


134


and along the outer skin of the user for massaging.




For example, the coplanar-flow devices may advantageously deliver the hydrotherapy coplanar flow


131


between the shoulder blades and down along the back of a user. Also, the coplanar-flow may be directed upward from the feet and ankles and along the calves of a user. Additionally, one may direct the coplanar-flow along the buttocks and hamstrings. Naturally, the coplanar flow will ride along and hug around the exposed skin surfaces of the user. This is fully intended and enhanced, to massage greater extents of key body regions of the user by directing the coplanar flow along the inner surface


134


of tub


136


, in accordance with the present invention.




As will be understood by those skilled in the art, benefits result from the positioning of flow channel


106


adjacent to flow channel


108


in device


100


(FIG.


1


). Added benefits result from the presence of protuberance


159


in device


100


, as discussed above. Also, the hydrotherapy-tub coplanar-flow device


100


may improve hydrotherapy flow at various locations within the hydrotherapy tub


136


.




As depicted in

FIG. 4

, another embodiment of the present invention includes dual fluid supply conduits


120


″ and split fluid supply conduit


118


″ for servicing dual slotted nozzles


102


″. In particular, partition or baffle


250


″ separates or divides fluid delivered from conduit


118


″ for flow through inlet


110


″ and dual flow passages


106


″. Furthermore, the dual slotted nozzles deliver dual, substantially coplanar flows


131


(FIG.


3


), for instance, in opposing directions


132


″.




As depicted in

FIGS. 5-6

, yet another embodiment of the present invention includes four openings


116


′″ and one opening


114


′″, split four ways by cooperating cross members


161


′″ and


162


′″ of respective intermediate plates


156


′″ and


158


′″. As will be understood by those skilled in the art, the resulting nozzle (not shown) would advantageously deliver four substantially coplanar flows


131


(

FIG. 3

) in four directions, for example, each offset by ninety degrees.




While part(s) of the description herein, for explanatory purposes, may imply certain exemplary direction(s), such direction(s) may be considered relative. For example, a “decline” of protuberance


159


may be provided relative to a local structure, yet present little or no “descending” component in a larger context. In another example, such a “decline” of the protuberance


159


may indeed correspond to an “absolute descent.” Design choice(s) allow accommodation(s) of any orientation(s) for any device(s) in accordance with the principles of the present invention.




Numerous alternative embodiments of the present invention exist. For instance, threaded interconnections could easily mount body


104


on inner surface


134


, fasten inlets


110


,


112


to fluid supply conduits


118


,


120


, or interconnect any upper and lower plates of body


104


. Further, the fluids could easily be liquid or gas. Moreover, each fluid could easily include a group of fluids. Also, more than two fluids could easily be merged into substantially coplanar flow


131


. For example, channels


106


,


108


could easily take on any variety of interrelationships, ranging from maximal to minimal fluid intermixing or other combination. Additionally, any number of the devices (e.g., device


100


″) could easily be secured by mechanisms such as sidewalls


200


with mating threads


202


and nut


204


. Furthermore, device


100


could easily be fixed in any desired direction


132


relative to a given incline of the inner surface


134


.




Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims.



Claims
  • 1. A hydrotherapy-tub coplanar-flow device, comprising:a body adapted for mounting on an inner surface of a hydrotherapy tub and attachable to first and second fluid supply conduits, said body having an interior channel, said interior channel having a first inlet for flow of water from said first fluid supply conduit, a second inlet for flow of air from said second fluid supply conduit, and a slotted nozzle configured to discharge said air and water in a substantially coplanar flow on said inner surface; said second inlet located on said interior channel between said first inlet and said slotted nozzle; and said interior channel further including an interior dam located between said first and second inlets, said dam forming a reduced cross-section area of said interior channel, the cross-sectional area of said interior channel then being increased between said dam and said second inlet.
  • 2. The device of claim 1, wherein said dam is configured to cause water from said first inlet to flow over said second inlet to draw said air from said second inlet to create a water and air froth which exits said slotted nozzle in said substantially coplanar flow.
  • 3. The device of claim 1, wherein said dam comprises a steep decline toward said second inlet.
  • 4. The device of claim 1, wherein said dam comprises at least one abrupt step.
  • 5. The tub of claim 1, wherein said interior dam extends between at least two different surfaces of said interior channel.
  • 6. A hydrotherapy tub, comprising:an inner surface; and at least one coplanar-flow device, comprising: a body adapted for mounting on said inner surface and attachable to first and second fluid supply conduits, said body having an interior channel, said interior channel having a first inlet for flow of water from said first fluid supply conduit, a second inlet for flow of air from said second fluid supply conduit, and a slotted nozzle configured to discharge said air and water in a substantially coplanar flow on said inner surface; said second inlet located, on said interior channel between said first inlet and said slotted nozzle; and said interior channel further including an interior dam located between said first and second inlets, said dam forming a reduced cross-sectional area of said interior channel, the cross-sectional area of said interior channel then increasing between said dam and said second inlet.
  • 7. The tub of claim 6, wherein said interior dam comprises a steep decline located between said first and second inlets.
  • 8. The tub of claim 6, wherein said steep decline is configured to cause flow of water to draw air from said second inlet to create a water and air froth which exits said slotted nozzle in said substantially coplanar flow.
  • 9. The tub of claim 6, wherein said interior dam extends between at least two different surfaces of said interior channel.
Parent Case Info

This application is a Continuation of U.S. patent application Ser. No. 09/253,476, filed Feb. 19, 1999, U.S. Pat. No. 6,351,859 which is a Continuation-In-Part of U.S. patent application Ser. No. 08/914,645, filed Aug. 19, 1997, abandoned. The priorities of both applications are claimed herein, and the entire disclosures of both are incorporated herein by reference.

US Referenced Citations (20)
Number Name Date Kind
469211 Kline Feb 1892 A
493194 Stifel et al. Mar 1893 A
745518 Pettengill Dec 1903 A
1511118 Fiduccia, Sr. Oct 1924 A
1512193 Berven Oct 1924 A
1769178 Delany Jul 1930 A
1772426 McConnell et al. Aug 1930 A
2336127 Rocke Dec 1943 A
2714725 Boone Aug 1955 A
3587976 Jacuzzi Jun 1971 A
4520514 Johnson Jun 1985 A
4546505 Wakenshaw Oct 1985 A
4563782 Dijkhuizen Jan 1986 A
4896384 Dijkhuizen Jan 1990 A
4953240 Gardenier Sep 1990 A
5063620 Mersmann Nov 1991 A
5418984 Livingston, Jr. May 1995 A
5514267 Machiya et al. May 1996 A
5546616 Bloemer et al. Aug 1996 A
6351859 Maiuccoro Mar 2002 B1
Continuations (1)
Number Date Country
Parent 09/253476 Feb 1999 US
Child 10/010337 US
Continuation in Parts (1)
Number Date Country
Parent 08/914645 Aug 1997 US
Child 09/253476 US