ACCESSIBLE BATHTUB

Abstract

Bathtubs and methods for making a bathtubs are disclosed. A bathtub may include a shell, a first door, and a second door. The shell defines a bathing well. A portion of the edge of the shell defines a door opening. The first door is coupled to a first side of the door opening. The second door is coupled to a second side of the door opening opposite the first side of the door opening. The first and second doors are movable into a closed position blocking the door opening.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 61/713,371 entitled “BATHTUB WITH INTEGRATED FRAME” and filed on Oct. 12, 2012 for George Bentley, which is incorporated herein by reference.

FIELD

This invention relates to bathtubs and more particularly relates to bathtubs that can be used by people with limited mobility.

BACKGROUND

People with limited mobility, such as elderly or disabled people, may have difficulty entering a bathtub by stepping over an edge of the tub, or sitting down in the interior of the tub, or bathing well. Accordingly, conventional bathtubs present a risk of slipping and falling for bathers with limited mobility. Accessible bathtubs reduce this risk by providing a door in the side of the tub, so that a bather can enter the bathing well without stepping over a high edge, and by providing a seat for the bather.

One type of accessible bathtub is the walk-in tub, which typically includes an inward-swinging door. Inward-swinging doors tend to prevent leaks, as water pressure forces the door into the door opening, for a tight seal. However, inward-swinging doors are typically narrow, to clear the seat when opening. Thus, a walk-in tub with an inward-swinging door is accessible by walking bathers, but less accessible by wheelchair users, or other bathers with difficulty walking.

Another type of accessible bathtub is the slide-in tub, which typically includes a large, outward-swinging door. Opening the door to a slide-in tub may expose most of the side of the bathing well, including the seat, so that a bather can slide into the tub from a wheelchair. However, slide-in tubs involve more complex sealing mechanisms than walk-in tubs, as water pressure may exert a large outward force on a large, outward-swinging door. Also, slide-in tubs may not fit in existing bathrooms that were not designed with space for opening a large, outward-swinging door.

SUMMARY

Bathtubs and methods for making bathtubs are disclosed. In various embodiments, a bathtub may include a shell, a first door, and a second door. In one embodiment, the shell defines a bathing well. In a further embodiment, a portion of the edge of the shell defines a door opening. In some embodiments, the first door is coupled to a first side of the door opening. In further embodiments, the second door is coupled to a second side of the door opening opposite the first side of the door opening. In certain embodiments, the first and second doors are movable into a closed position blocking the door opening.

In one embodiment, the first door is an inward-swinging door and the second door is an outward-swinging door. In a further embodiment, a lip for the first door prevents the first door from opening outward, and a lip for the second door prevents the second door from opening inward. In another embodiment, the lip for the first door interfaces with the lip for the second door in the closed position, to seal a junction between the doors.

In one embodiment, the first door provides access to a foot well and the second door provides access to a sea. In a certain embodiment, the seat is integral to the shell. In further embodiments, the seat includes a front central portion, front side portions, and a back portion. In one embodiment, the front central portion extends in an upwardly sloped direction from the back portion. In a further embodiment, the front side portions extend in a downwardly sloped direction from the back portion. In some embodiments, a portion of the shell behind the seat extends up from the back portion of the seat in a backwardly sloped direction, forming an inclined seat back. In further embodiments, a portion of the shell beneath the seat extends down from the front central portion and front side portions of the seat in a backwardly sloped direction, forming a foot well with a recess under the seat for a bather's heels.

In one embodiment, first and second latches are operable to secure the first and second doors, respectively, in the closed position. In a further embodiment, in the closed position, the first door interferes with releasing the second latch, so that the second door is not openable unless the first door is opened.

In another embodiment, a door handle is attached to the second door. In a further embodiment, the door handle is movable to secure the first and second doors in the closed position by securing the first door between the door handle and a lip for the second door.

In one embodiment, a metal frame is disposed beneath the shell. In a further embodiment, the metal frame includes adjustable legs. In certain embodiments, structural members are bonded to the shell. In some embodiments, at least one of the structural members may be disposed between the shell and a layer of fiber-reinforced polymer. In further embodiments, at least one of the structural members may be bonded to the layer of fiber-reinforced polymer. In certain embodiments, the structural members may include a wood structural member, a foam structural member, and/or a honeycomb structural member. In some embodiments, the structural members may include one or more panels supporting the shell.

In another embodiment of a bathtub, a shell defines a bathing well. In a further embodiment, a portion of the edge of the shell defines a door opening. In one embodiment, first and second doors are movable into a closed position blocking the door opening. In a certain embodiment, a first hinge couples the first door to the door opening. In a further embodiment, the first hinge allows the first door to open into the bathing well. In one embodiment, a second hinge couples the second door to the door opening. In a further embodiment, the second hinge allows the second door to open away from the bathing well. In some embodiments, first and second latches are operable to secure the first and second doors, respectively, in the closed position.

In a certain embodiment, structural members may be disposed between the shell and a layer of fiber-reinforced polymer. In a further embodiment, the structural members may be bonded to the shell and to the layer of fiber-reinforced polymer.

In one embodiment, a method for making a bathtub includes forming a shell. In a certain embodiment, the shell defines a bathing well, and a portion of the edge of the shell defines a door opening. In one embodiment, the method includes bonding structural members to the shell. In a further embodiment, the method includes coupling a first door to the door opening using an interior hinge. In a certain embodiment, the method includes coupling a second door to the door opening using an exterior hinge. In some embodiments, the method includes moving the first and second doors into a closed position blocking the door opening.

In a certain embodiment, forming the shell may include applying shell material to a mold. In a further embodiment, forming the shell may further include removing a portion of the mold with the shell.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating one embodiment of a shell for a bathtub;

FIG. 2 is a perspective view further illustrating one embodiment of a bathtub that includes the shell of FIG. 1;

FIG. 3 is an enlarged view illustrating a portion of the bathtub of FIG. 2;

FIG. 4 is a section view illustrating one embodiment of bathtub doors;

FIG. 5 is a perspective view illustrating one embodiment of a door handle;

FIG. 6 is a perspective view illustrating one embodiment of a support structure for a bathtub; and

FIG. 7 is a schematic block diagram illustrating one embodiment of a method for making a bathtub.

DETAILED DESCRIPTION

Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.

Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are included to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

The schematic flow chart diagrams included herein are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

FIG. 1 depicts one embodiment of a shell 100 for a bathtub. In the depicted embodiment, the shell 100 defines a bathing well 102 and a door opening 106. In various embodiments, the shell 100 may or may not include additional features shown in the depicted embodiment, such as a deck 104, a seat 110, a seat back 108, a foot well 112, and a heel recess 114.

In one embodiment, the shell 100 defines a bathing well 102. The bathing well 102, in various embodiments, may refer to the space in which a person sits while bathing, which may be filled with water. In bathtubs with doors, the bathing well 102 may refer to the space available for holding water when the doors are closed.

In the depicted embodiment, the edge of the shell 100 defines a deck 104 and a door opening 106. As used herein, the edge of the shell 100 refers to an uppermost portion of the shell 100, where water might spill out of the bathing well 102 or leak under the doors, rather than to a physical edge of the material that forms the shell 100. For example, in the depicted embodiment, the shell 100 is molded with the physical edge of the material that forms the shell 100 pointing downward or outward. The material pointing downward in the front of the shell 100 may form all or part of an apron for the bathtub. However, the door opening 106 is still defined by a portion of the edge (or uppermost portion) of the shell 100. In various embodiments, a door opening 106 may refer to a space or opening in a side wall of a bathtub that provides a bather with access into the bathing well 102. In certain embodiments, a door or doors may be movable into a closed position blocking the door opening 106, as shown in FIG. 2, to allow the bathtub to be filled.

In one embodiment, the door opening 106 may be configured to accommodate two doors, as described below with regard to FIG. 2. However, in another embodiment, the shell 100 may include a door opening 106 configured to accommodate a single door, such as the inward-swinging door of a walk-in tub.

The remainder of the edge of the shell 100, other than the portion that defines the door opening 106, may form a deck 104. In various embodiments, the deck 104 may refer to a lip, or perimeter of the tub. In certain embodiments, hardware such as faucets, handles, detachable showerheads, grab bars, or the like may be mounted to the deck 104. In other embodiments, hardware may be mounted in other places such as on a bathroom wall. The deck 104 may also be useful in some embodiments for storing soap, shampoo, and/or other bathing supplies. In another embodiment, the shell 100 may not include a deck 104. For example, a shell 100 for an undermount tub may be intended for mounting underneath a separate deck, such as a stone or tile surface, or the like, and therefore may not include a deck 104 formed by the edge of the shell 100.

In one embodiment, a bathtub may include a seat 110. In the depicted embodiment, the seat 110 is integral to the shell 100. In another embodiment, the seat 110 may not be integral to the shell 100, but may be removable to provide a deeper bathing well 102 for bathers who do not wish to use a seat 110. An integral seat 110, in various embodiments, may be formed or molded as part of the shell 100. Molding a seat 110 into the shell 100 presents fewer surfaces to clean, and prevents the seat 110 from slipping when in use. Using an integral seat 110 also allows the seat 110 to include other features, such as a seat heater, hydrotherapy jets, or the like.

In one embodiment, the seat 110 may include a back portion, a front central portion, and front side portions. As used herein, directional terms such as “front,” “back” up,” “down,” “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like, when used with reference to the shell 100 or bathtub in general, refer to the perspective of a user facing the door opening 106 from outside the tub. Thus, the door opening is in the front of the shell 100. However, similar directional terms when used with reference to the seat 110 refer to the perspective of a bather in the seat 110, so that the bather's legs extend off the front of the seat 110. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. However, these terms are not intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” surface can become a “lower” surface simply by turning the object over. Nevertheless, it is still the same object.

The back portion of the seat 110 may support a seated bather, and may be contoured for comfortable sitting. The front central portion may extend forward in an upwardly sloped direction from the back portion, forming a raised area, or hump, that allows a bather to sit comfortably without sliding off the edge of the seat 110. The bather's legs may rest in the front edge portions of the seat 110, which may extend from the back portion in a downwardly sloped direction, allowing water to drain off the surface of the seat 110. Thus, in one embodiment, the seat 110 may be in a saddle shape. In another embodiment, however, the seat 110 may have a different shape. For example, in a further embodiment, the seat may 110 may be flat.

In one embodiment, the shell 100 may include a seat back 108. In the depicted embodiment, a portion of the shell 100 extends up from the back portion of the seat 110 to form the seat back 108. In a certain embodiment, that portion of the shell 100 may extend up from the back portion of the seat 110 in a backwardly sloped direction to form an inclined seat back 108, which allows a bather to lean backwards in the bathtub.

In one embodiment, the shell 100 may form a foot well 112. As used herein, a foot well 112 may refer to a portion of the bathing well 102 in front of the seat 110. Thus a bather positioned on the seat 110 may soak his or her feet in the foot well 112. In some embodiments, the seat 110 and the foot well 112 may define two separate depths for the bathing well 102, so that the tub is shallower near the seat 110, and deeper near the foot well 112. In a further embodiment, the foot well 112 may be the lowest part of the bathing well 102, and a drain may be placed in the foot well 112. In a certain embodiment, the shell 100 may extend down from the front edge (the front central portion and front side portions) of the seat 110 to the bottom of the footwell 112. In a further embodiment, the portion of the shell 100 beneath the seat 110 may extend down from the front central portion and front side portions of the seat 110 in a backwardly sloped direction, forming a foot well 112 with a heel recess 114.

In various embodiments, a heel recess 114 may refer to a recess, or an extension of the foot well 112 underneath the seat 110. In some embodiments, a bather's heels may rest in the heel recess 114 under the seat 110. In the depicted embodiment, the heel recess 114 may extend approximately five inches beneath the seat 110. In other embodiments, the heel recess 114 may extend a greater or lesser distance under the seat 110. In embodiments where the bathtub includes a heel recess 114, bathers may tuck their legs underneath themselves in a seated position. This facilitates additional hydrotherapy options compared to a tub without a heel recess 114. For example, a bather may exercise by performing squatting motions above the seat 110 with his or her feet in the heel recess 114. The heel recess 114 also may allow an inward-swinging door to clear the bather's feet, even if the threshold for the door opening 106 is low. (A low threshold for the door opening 106 may allow easy access into or out of the bathtub.)

In various embodiments, the shell 100 may include various other features not shown in FIG. 1, such as a textured non-slip base, arm rests for the seat 110, openings for a drain, an overflow drain, hydrotherapy jets, deck-mounted hardware, or the like. A bathtub including the shell 100 may also include various other components and plumbing hardware. For example, in one embodiment, a grab bar may be installed in or near the bathing well 102. In another embodiment, the bathtub may be installed with thermostatic filler valves, preventing cold water shock or hot water scalding. In a further embodiment, the filler valves and the drain may have a larger diameter than conventional tubs, promoting fast filling and draining of the bathtub. For example, the filler valves may have a ¾ inch diameter, and the drain may have a 3 inch diameter. In a certain embodiment, a shower system for the bathtub is provided with valves separate from the filler valves. In another embodiment, the bathtub is provided with plumbing fixtures similar to those used with conventional tubs. For example, standard filler valves may be used with a diverter that diverts water from the fill spout to the shower. In light of this disclosure, it is clear that many possible plumbing components and other components may be used with a bathtub that includes the shell 100.

The shell 100, in various embodiments, may be formed of various materials, using various methods. For example, in one embodiment, the shell 100 may be formed by vacuum-forming a heated acrylic sheet to a negative mold. In a further embodiment, an acrylic shell 100 may be strengthened by one or more exterior fiberglass layers. In another embodiment, the shell 100 may be formed using a fiberglass hand-layup or spray-layup process with a positive mold. In another embodiment, a composite shell 100 may be formed by resin transfer molding using a closed mold. In view of this disclosure, many molding and other forming processes are clear which may be suitable for forming the shell 100

In certain embodiments, such as where the shell 100 includes a heel recess 114, a mold for the shell 100 may not be completely convex or concave (depending on whether a positive or negative mold is in use). Accordingly, a mold for the shell 100 may include at least one removable “knock-off,” so that forming the shell 100 includes applying shell material to the mold, waiting for the material to cure or harden, and removing the knock-off portion of the mold along with the shell 100. The knockoff may then be removed from the shell 100 and reattached to the mold.

FIG. 2 depicts one embodiment of a bathtub 200 that includes the shell 100 of FIG. 1, including the bathing well 102 and door opening 106. In the depicted embodiment, the bathtub 200 further includes a first door 202 and a second door 204. In various embodiments, the bathtub 200 may or may not include additional features shown in the depicted embodiment, such as side panels 206, a maintenance panel 208, one or more hinges 210, lips 212 for the first door 202 and second door 204, and door handles (shown enlarged in FIG. 3).

In one embodiment, the first door 202 is coupled to a first side of the door opening, and the second door 204 is coupled to a second side of the door opening 106 opposite the first side of the door opening 106. As described above, the first door 202 and second door 204 are movable into a closed position blocking the door opening 106. FIG. 2 depicts the bathtub 100 with the doors 202, 204 in the closed position.

In one embodiment, the doors 202, 204 may be formed using the same technique as the shell 100, for a consistent surface finish. For example, the doors 202, 204 for a fiberglass shell 100 may be made by molding fiberglass into exterior and interior portions for each door 202, 204, then bonding the interior and exterior portions together and sealing the seam against water leaks. Similarly, in another embodiment, vacuum-formed acrylic doors 202, 204, may be used with a vacuum-formed acrylic shell 100. In certain embodiments, however, the doors 202, 204 may be made from a different material than the shell 100, or using different techniques. For example, in one embodiment, the doors 202, 204 may be formed by resin transfer molding even if the shell 100 is formed using a different technique.

In one embodiment, the first door 202 may provide access to the foot well 112, and the second door 204 may provide access to a seat 110. Thus, in the depicted embodiment, the first door 202 may be approximately as tall as the depth of the bathing well 102 in the foot well 112 area, and approximately as wide as the foot well 112 so that a bather may open the first door 202 and walk into the foot well 112 over a low threshold. Also, in the depicted embodiment, the second door 204 may be approximately as tall as the depth of the bathing well 102 over the seat 110, and approximately as wide as the seat 110, so that opening the second door 204 exposes the edge of the seat 110, allowing a bather to slide onto the seat 110 from a wheelchair or from a similar seated position. A bather may open both doors 202, 204 to slide onto the seat 110, so that his or her legs can enter the foot well 112 over a low threshold instead of over the first door 202. The door opening 106 may be shaped to accommodate a tall first door 202 and a shorter second door 204, so that the tops of both doors 202, 204 are aligned with the deck of the tub 100

In one embodiment, the first door 202 may open by swinging inward, toward or into the bathing well 102. For example, the first door 202 may be coupled to a first side of the door opening 106 by an interior hinge (not shown), enabling the first door 202 to open into the bathing well 102. In a further embodiment, the second door 204 may open by swinging outward, away from or out of the bathing well 102. For example, the second door 204 may be coupled to a second side of the door opening 106 by an exterior hinge 210. In various embodiments, the hinges 210 may include hinges 210 of various types, such as stainless steel hinges, flexible plastic hinges, or other types of hinges suitable for allowing the doors 202, 204 to pivot about the hinges 210. In view of this disclosure, it is clear that many types of hinge 210 are suitable.

In another embodiment, the doors 202, 204 may be coupled to the door opening 106 in a different way. For example, in one embodiment, the doors 202, 204 may be removably coupled to the door opening 106, and held in place by fasteners and/or by water pressure when in use. In another embodiment, the doors 202, 204 may be slidably coupled to the door opening 106.

In the depicted embodiment, the doors 202, 204 are coupled to opposite sides of the door opening 106 and meet in the middle to seal a junction between the first door 202 and the second door 204. In another embodiment, the doors 202, 204 may be coupled to the door opening 106 in different places.

In general, a bathtub 200 with two doors 202, 204 provides a large opening for easy walk-in or slide-in access to the bathtub, but, because a double-door bathtub 200 uses two smaller doors 202, 204 instead of one large door, it is more likely to fit in existing bathrooms, which may not include space for opening a larger door. For example, the second door 204 may be configured to clear a toilet seat when opening outward. In one embodiment, where the first door 202 opens inward and the second door 204 opens outward, the second door 204 does not involve the complex sealing mechanisms typically associated with a large outward-swinging door, because the force due to water pressure is smaller on the smaller surface of the second door 204. Thus, water pressure may hold the inward-swinging first door 202 in place, and a simple latch may be sufficient to hold the second door 204 in place with a water-tight seal.

In the depicted embodiment, each of the doors 202, 204 includes a lip 212 that keeps the door 202, 204 from opening in the wrong direction. In one embodiment, an outward-facing lip 212 toward the inside of the first door 202 prevents the first door 202 from opening outward. In a similar embodiment, an inward-facing lip 212 toward the outside of the second door 202 may prevent the second door 202 from opening inward. In various embodiments, seals may be disposed in the lips 212 of the doors 202, 204, or in the shell 100 near the door opening 106, so that water does not escape the bathing well 102 when the doors 202, 204 are in the closed position. In one embodiment, the lip 212 for the first door 202 may overlap or interface with the lip 212 for the second door 204 when the doors 202, 204 are in the closed position, thus sealing the junction between the doors 202, 204.

In various embodiments, the seals may include gaskets molded into the doors 202, 204 or into the shell 100 near the door opening 106, gaskets disposed within channels routed into the doors 202, 204 or into the shell 100 near the door opening 106, gaskets bonded to surfaces of the doors 202, 204, or the shell 100, or the like. In one embodiment, the seals may include double gaskets to comply with International Association of Plumbing and Mechanical Officials (IAPMO) standards. In another embodiment, the seals may include a single gasket with an overflow drain in the threshold of the door opening 106, to comply with IAPMO standards. In a certain embodiment, the seals may not comply with IAPMO standards, but may nevertheless create a water-tight junction that keeps water in the bathing well 102.

In one embodiment, the bathtub 200 may include side panels 206. Side panels 206 may be made of shell material or other material, and may extend downward from the shell 100 to a bathroom floor, presenting a finished appearance for the bathtub 200. Using separate side panels 206 instead of extending the shell 100 to the bathroom floor reduces the complexity of the mold for the shell 100. Nevertheless, in another embodiment, the shell 100 may extend to the bathroom floor without the use of side panels 206. In the depicted embodiment, the bathtub 200 is configured for installation in a three-wall alcove. Accordingly, the side panels 206 present a finished appearance for an apron, or skirt on the front side, but the back and other sides are uncovered. In another embodiment, the bathtub 200 may be configured for installation as a freestanding tub, or near fewer walls, and may include side panels 206 that present a finished appearance on all or some of the tub sides.

In the depicted embodiment, one of the side panels 208 includes a maintenance panel 208. In another embodiment, one of the side panels 206 may be a removable maintenance panel 208. One or more maintenance panels 208, in various embodiments, may provide access to components under the shell 100. For example, in the depicted embodiment, a motor for air or water hydrotherapy jets may be placed under the seat 110, and accessed by removing the maintenance panel 208.

FIG. 3 depicts one embodiment of the circled portion of the bathtub 200 of FIG. 2, in an enlargement. The enlargement shows portions of the first and second doors 202, 204, including the lips 212 of the doors 202, 204 interfacing to seal the junction between the doors 202, 204, as described above with regard to FIG. 2. In the depicted embodiment, the bathtub 200 also includes door handles 302, 304. In one embodiment the door handle 302 for the first door 202 operates a latch to open the first door 202, or to secure the first door 202 in the closed position. In a further embodiment, the door handle 304 for the second door 204 operates a latch to open the second door 204, or to secure the second door 204 in the closed position. In the depicted embodiment, the door handle 302 for the first door 202 is palm-activated. Using a palm-activated door handle instead 302, instead of a knob or the like, allows arthritic bathers, or other people with limited use of their hands, to operate the door 202 unassisted. For example, an amputee may be able to operate the door handle 302 for the first door 202 using an arm without a hand.

A palm-activated door handle 302 is convenient for use in an embodiment where the first door 202 opens inward, as water pressure will prevent the door 202 from opening even if the door handle 302 is inadvertently activated. In one embodiment, the door handle 304 for the second door 204 may also be palm-activated. However, in certain embodiments, the second door 204 may open outward, creating a risk that the second door 204 may open before the bathtub 200 is drained and spill significant quantities of water out of the bathtub 200, if the door handle 304 for the second door 204 is inadvertently activated. In some embodiments, the ability to open the second door 204 before the bathtub 200 has drained may be useful for emergency access to the bathtub 200. In certain embodiments, however, the door handle 304 for the second door 204 may be configured so that the second door 204 is not openable until the bathtub 200 has drained enough to open the first door 202. For example, in the depicted embodiment, the door handle 304 for the second door 204 is a lever that moves in the direction of the first door 202 to release a latch for the second door 204. Thus, when the doors 202, 204 are in the closed position, the first door 202 prevents the lever from moving, thus interfering with a bather's ability to operate the door handle 304 to release the latch for the second door 204. Accordingly, the second door 204 is not openable unless the first door 202 is opened.

FIG. 4 depicts one embodiment of the doors 202, 204 in cross-section, including door handles 302, 304 as described above with regard to FIG. 3. In the depicted embodiment, the bathtub 200 includes first and second latches 402, 404 operable to secure the first and second doors 202, 204, respectively, in the closed position. In one embodiment, the latches 402, 404 secure the doors 202, 204 in the closed position by extending into holes in corresponding strike plates. For example, in the depicted embodiment, the first latch 402 secures the first door 202 in position by extending into a strike plate in the second door 204. In another embodiment, the first latch 402 may extend into a strike plate in the shell 100. Operating the first door handle 302 retracts the first latch 402 from the strike plate, allowing the first door 202 to be opened. In the depicted embodiment, the second latch 404 similarly secures the second door 204 in position by extending into a strike plate in the shell 100, so that operating the second door handle 304 retracts the second latch 404, allowing the second door 204 to be opened. The latches 402, 404 may be in various other positions in various embodiments. For example, in one embodiment, the latches 402, 404 may be disposed in the shell 100, and may extend into strike plates in the doors 202, 204. In view of this disclosure, it is clear that many arrangements of doors 202, 204 and latches 402, 404 are possible.

FIG. 5 depicts one embodiment of a single door handle 500 that may be used with a bathtub, such as the bathtub 200 of FIG. 2, in place of the separate door handles 302, 304. In one embodiment, the single door handle 500 may be attached to the second door 204. In a further embodiment, a bather may secure the doors 202, 204 in the closed position by moving the door handle 500 to secure the first door 202 between the door handle 500 and a lip 212 for the second door 204. For example, in one embodiment, the single door handle 500 may be a sliding bolt attached to the second door 204. A sliding bolt may be retracted to close the doors 202, 204, then extended to secure the first door 202 against the lip 212 of the second door 204. In various embodiments, the single door handle 500 may be a sliding bolt, an eccentric wheel, a pivotable handle, or the like.

In the depicted embodiment, the door closer 500 includes a handle 502, a pivot point 504, a pressure point 506, and a screw opening 508. In one embodiment, the pivot point 504 is pivotally attachable to an inside portion of the second door 204near the door opening, and the handle 502 extends from the pivot point. In the depicted embodiment, the screw opening 508 may admit a set screw which attaches the door closer 500 at the pivot point 504 to a pivoting member embedded in, or attached to the second door 204. In various other embodiments, other methods may be used to pivotally attach the door closer 500 to the second door 204. In a further embodiment, the pressure point 506 is offset from the handle 502. In a different embodiment, though, the pressure point 506 is in line with the handle 502.

To seal the doors 202, 204 closed, a bather brings the doors 202, 204 into the closed position, then rotates the handle 502 about the pivot point 504, bringing the pressure point 506 across the first door 202, so that it is pressed against the lip 212 of the second door 204. Placing the pressure point 506 at an offset position from the handle 502, in certain embodiments, prevents the edge of the first door 202 from hitting a bather's knuckles on the handle 502 as the first door 202 is closed. In a certain embodiment, the handle 502 may have other features facilitating easy use, such as an enlarged end portion 510 for easy gripping, or a narrower gripping portion 512 configured to be positioned approximately one and one quarter inches from the wall of the bathtub 200. A 1¼ inch distance between a handle 502 and the wall is similar to the distance between commonly available grab bars as installed on a wall, and provides a space that is wide enough for people to comfortably grasp the handle 502, but narrow enough to avoid trapping or injuring peoples' wrists if their hands slip.

FIG. 6 depicts one embodiment of a support structure 600 for a bathtub, such as the bathtub 200 of FIG. 2. In the depicted embodiment, the support structure 600 includes a front support panel 602, a back support panel 604, cross supports 606, a pump support 608, and a metal frame 610.

In one embodiment, the front support panel 602 and the back support panel 604 may support front and back sides of the shell 100, respectively. In another embodiment, the front support panel 602 and the back support panel 604 may be replaced by other supports, such as separate panels on either side of the door opening 106, vertical supports, or the like. However, using panels 602, 604 to support the full length of the shell 100 reduces flexing that can damage the shell 100.

In one embodiment, the panels 602, 604 may be configured to fit the shell 100. For example, in the depicted embodiment, the front support panel 602 includes a cutout for the door opening 106, and a cutout for accessing the pump support 608 via a maintenance panel 208. The back support panel 604, in the depicted embodiment, also includes a cutout for accessing the pump support 608 and a cutout that allows the shell 100 to extend past the back support panel 604, to increase the volume of the bathing well 102. Thus, in the depicted embodiment, the back support panel 604 supports the shell 100 at an intermediate height along the shell 100, so that the bathing well 102 is larger, but the full height of the shell 100 is less supported. In another embodiment, however, the back support panel 604 may include a level top edge and may support the shell 100 at its full height. However, the top of the bathing well 102 will then be narrower by the thickness of the back support panel 604. In further embodiments, the support panels 602, 604 may include additional openings for hydrotherapy jets, or the like.

In one embodiment, the support panels 602, 604 may be plywood panels which extend from the front of the bathtub 200 to the back, along both sides. Plywood panels 602, 604 support the bathtub 200 inexpensively, but in other embodiments, other materials such as PVC foam core, marine structural foam, honeycomb panels, resin-enhanced balsa wood, pressure treated wood, untreated wood, or the like, may also be used for the support panels 602, 604.

In one embodiment, the material for the shell 100 may wrap over the edge of the shell 100, forming a U-shaped pocket for the front and back support panels 602, 604. In this embodiment, the thickness the U-shaped pocket is determined by the thickness of the support panels 602, 604. For example, a plywood support panel 602, 604 may have a 23/32 inch thickness, or a ¾ inch nominal thickness, which fits a corresponding ¾ inch pocket in the shell 100.

In the depicted embodiment, the support panels 602, 604 are bonded to the shell 100, and foam is disposed in any gaps between the shell 100 and each support panel 602, 604. Foam may provide additional bonding and a rigid structure where the shell 102 meets a support panel 602, 604. In one embodiment, the foam may be a spray foam sealant. In another embodiment, the foam may be a two-part expanding polyurethane foam. In light of this disclosure, many types of foam are clearly suitable for use in gaps between the shell 100 and a support panel 602, 604.

In one embodiment, cross supports 606 may extend transversely beneath the bathtub 200, joining the front support panel 602 and the back support panel 604. The cross supports 606 may support the shell 100 underneath the bathing well 102. Thus, in the depicted embodiment, the cross supports 606 are positioned at various heights to support both the seat 110 and the foot well 112. Cross supports 606 may provide rigidity to the shell 100, so that a thin shell 100 for the bathtub 200 may be less likely to spider or crack.

In various embodiments, the bathtub 200 may include structural members bonded to the shell 100. In certain embodiments, structural members may include members of the support structure 600, such as support panels 602, 604, or cross supports 606. In further embodiments, structural members may include additional ribs, panels, or the like, that are bonded to the shell 100, but not included in the depicted support structure 600. For example, a side of the shell 100 opposite the seat 110 may include a large, mostly vertical surface area, which may flex and crack under repeated use, but which is not supported by many cross supports 606 due to being largely vertical. Additional ribs or panels may therefore be bonded to the shell 100 in some embodiments, to stiffen and support the shell 100 in that region. In certain embodiments, the support panels 602, 604, cross supports 606, or other structural members may include various materials, such as plywood, pressure treated wood, untreated wood, PVC foam core, marine structural foam or other foam, honeycomb panels, resin-enhanced balsa wood, or the like.

In various embodiments, the structural members may be bonded to the shell 100 in various ways. For example, in one embodiment, the structural members may be bonded to the shell 100 with a mastic adhesive. In another embodiment, the structural members and the shell 100 may be bonded together with an epoxy adhesive. In light of this disclosure it is clear that in various embodiments, different adhesives may be used to bond the structural members to the shell 100, depending on the materials used for the structural members and the shell 100. Bonding the structural members to the shell 100 creates a sturdy unified structure by comparison to a metal-framed tub where the shell 100 is strapped to the frame only at certain points.

In one embodiment, at least one of the structural members may be disposed between the shell 100 and a layer of fiber-reinforced polymer. In various embodiments, a layer of fiber-reinforced polymer may include a polymer matrix reinforced with fibers. In certain embodiments, the polymer matrix may include epoxy, vinylester, polyester, phenol formaldehyde resin, or the like. In further embodiments, the reinforcing fibers may include glass fibers, carbon fibers, aramid fibers, or the like. For example, in one embodiment, the shell 100 may be gelcoated fiberglass, and support members may be positioned on the shell 100, and coated with additional layers of glass fibers and resin. In another embodiment, the shell 100 may be vacuum-formed acrylic, and fiberglass layers may be used to strengthen the shell 100 and to attach structural members to the shell 100. Although fiberglass is currently an inexpensive and effective fiber-reinforced polymer, other fiber-reinforced polymers may be used in other embodiments. In certain embodiments, a layer of fiber-reinforced polymer may be one of multiple layers.

In a further embodiment, structural members disposed between the shell 100 and a layer of fiber-reinforced polymer may be bonded to the shell 100 and to the layer of fiber-reinforced polymer, forming a sandwich-structured composite. Bonding between layers of a sandwich-structured composite bathtub 200 may provide a lightweight bathtub 200 that is stronger than it would be if the layers were not bonded together.

In one embodiment, a pump support 608 joins the support panels 602, 604, and provides support for items that may be located under the seat 110. For example, a motor for hydrotherapy jets may be located under the seat 110, and supported by the pump support 608. The pump support 608 may be made out of the same material as the support panels 602, 604, or the cross members 608, or out of various other materials.

In the depicted embodiment, a metal frame 610 is disposed beneath the shell 100, and supports the support panels 602, 604. In the depicted embodiment, the metal frame 610 is rectangular, and supports the edges of the tub at the front, back and sides, with an open portion in the middle. In a further embodiment, the metal frame 610 may include adjustable legs (not shown), which allow an installer to adjust the height of each corner of the bathtub 200. For example, in one embodiment, threaded legs may be screwed into or out of openings in the metal frame 610, to adjust the height of each corner. In view of this disclosure, it is clear that other embodiments of the metal frame 610 and legs are possible using other materials and configurations. For example, a non-rectangular bathtub 200 may in include a non-rectangular metal frame 610.

Adjusting the height of the bathtub 200 corners may be useful if the bathroom floor is not level, or depending on the location of the P-trap for the bathtub 200. In some embodiments, the P-trap for the tub drain is installed in the bathroom floor on the same side of the bathroom as the drain opening in the bathtub 200 itself. If the drain opening is on the same side as the P-trap, a metal frame 610 may be omitted, and the bathtub 200 may be installed directly on the subfloor of the bathroom. However, if the bathtub 200 is to be installed with the drain opening on the opposite side of the bathtub 200 from the P-trap, a drain line will run under the bathtub 200, and a support frame 610 may be used to raise the bathtub 200, to accommodate the drain line.

FIG. 7 is a schematic block diagram illustrating one embodiment of a method 700 for making a bathtub 200. The method 700 begins with forming 702 a shell 100. As described above with regard to FIG. 1, in certain embodiments, the shell 100 may define a bathing well 102, and a portion of the edge of the shell 100 may define a door opening 106. In some embodiments, forming 702 the shell 100 may include applying shell material to a mold, and removing a portion of the mold, such as a knock-off, with the shell. In a further embodiment, the method 700 includes bonding 704 structural members to the shell 100. In a certain embodiment, the method 700 includes coupling 706 a first door 202 to the door opening 106 using an interior hinge. In a further embodiment, the method 700 includes coupling 708 a second door 204 to the door opening 106 using an exterior hinge 210. In certain embodiment, the method 700 ends with moving 710 the first and second doors 202, 204 into a closed position blocking the door opening 106.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A bathtub comprising:

a shell defining a bathing well, a portion of an edge of the shell defining a door opening;

a first door coupled to a first side of the door opening; and

a second door coupled to a second side of the door opening opposite the first side of the door opening, the first and second doors movable into a closed position blocking the door opening.

2. The bathtub of claim 1, wherein the first door is an inward-swinging door and the second door is an outward-swinging door.

3. The bathtub of claim 2, wherein a lip for the first door prevents the first door from opening outward and a lip for the second door prevents the second door from opening inward.

4. The bathtub of claim 3, wherein the lip for the first door interfaces with the lip for the second door in the closed position to seal a junction between the doors.

5. The bathtub of claim 1, wherein the first door provides access to a foot well and the second door provides access to a seat.

6. The bathtub of claim 1, further comprising a seat integral to the shell, the seat comprising a front central portion, front side portions, and a back portion, the front central portion extending in an upwardly sloped direction from the back portion, and the front side portions extending in a downwardly sloped direction from the back portion.

7. The bathtub of claim 6, wherein a portion of the shell behind the seat extends up from the back portion of the seat in a backwardly sloped direction, forming an inclined seat back.

8. The bathtub of claim 6, wherein a portion of the shell beneath the seat extends down from the front central portion and front side portions of the seat in a backwardly sloped direction, forming a foot well with a recess under the seat for a bather's heels.

9. The bathtub of claim 1, further comprising first and second latches operable to secure the first and second doors, respectively, in the closed position.

10. The bathtub of claim 9, wherein, in the closed position, the first door interferes with releasing the second latch, so that the second door is not openable unless the

first door is opened.

11. The bathtub of claim 1, further comprising a door handle attached to the second door, the door handle movable to secure the first and second doors in the closed position by securing the first door between the door handle and a lip for the second door.

12. The bathtub of claim 1, further comprising a metal frame disposed beneath the shell, the metal frame comprising adjustable legs.

13. The bathtub of claim 1, further comprising structural members bonded to the shell.

14. The bathtub of claim 13, wherein at least one of the structural members is disposed between the shell and a layer of fiber-reinforced polymer and bonded to the layer of fiber-reinforced polymer.

15. The bathtub of claim 13, wherein the structural members comprise one or more of a wood structural member, a foam structural member, and a honeycomb structural member.

16. The bathtub of claim 13, wherein the structural members comprise one or more panels supporting the shell.

17. A bathtub comprising:

a shell defining a bathing well, a portion of an edge of the shell defining a door opening;

first and second doors movable into a closed position blocking the door opening;

a first hinge coupling the first door to the door opening, the first hinge enabling the first door to open into the bathing well;

a second hinge coupling the second door to the door opening, the second hinge enabling the second door to open away from the bathing well; and

first and second latches operable to secure the first and second doors, respectively, in the closed position.

18. The bathtub of claim 17, further comprising one or more structural members disposed between the shell and a layer of fiber-reinforced polymer and bonded to the shell and the layer of fiber-reinforced polymer.

19. A method for making a bathtub, the method comprising:

forming a shell, the shell defining a bathing well, a portion of an edge of the shell defining a door opening;

bonding structural members to the shell;

coupling a first door to the door opening using an interior hinge;

coupling a second door to the door opening using an exterior hinge; and

moving the first and second doors into a closed position blocking the door opening.

20. The method of claim 19, wherein forming the shell comprises applying shell material to a mold and removing a portion of the mold with the shell.