Patent Publication Number: US-2023160245-A1

Title: Bathtub door hinge assembly and method

Description:
TECHNICAL FIELD 
     This invention relates generally to door hinges, and more particularly to door hinge assemblies for walk-in type bathtubs. 
     BACKGROUND OF THE INVENTION 
     Generally, many elderly or mobile-restricted persons find bathing to be awkward and difficult with conventional step-over side-wall bathtubs. The outside wall of side-wall bathtubs, while retaining water for bathing, presents an obstacle over which the bather must step in order to enter and egress the bathtub. Lifting the bather&#39;s leg and moving over the upper edge of the side wall requires balance and care. 
     Bathtubs have been developed for use by the elderly and mobility-restricted persons, which feature deep water-holding cavities and include a door that enables “walk-in” ingress and egress to and from the bathtub through a passage in a sidewall closed by the door. The threshold of such passage is lower than an upper extent of the side wall. The bather opens the door when entering the walk-in bathtub, and then close and seal the door behind the bather to prevent water from escaping the bathtub during use. To exit the bathtub, the bathtub is drained to a water level lower than a threshold, and then the door is unsealed and opened. 
     Bathtubs having the door sealed against the outside or exterior of the bathtub, bathtub surround, or bathtub door jamb must have a very good seal and latching device to prevent water from leaking about the door. Even with a very good seal, water leakage may occur between the door and bathtub surround. Therefore, some bathtubs are designed to have the door sealed against the inside or interior surface of the bathtub, so that the hydrostatic pressure of the water within the bathtub forces the door against the seal and door jamb to provide a better sealing of the door. 
     However, a problem with these interior sealing doors is that the door swings into the bathtub when the door is opened, and thus the door encroaches into the bathtub area occupied by the bather. As a result, the bathtub must be made bigger than necessary to accommodate both the person within the bathtub and the area of door movement. Also, the inward swinging of the door forces the person within the bathtub to move out of the way of the swinging door, which increases the possibility of the person slipping or falling within the bathtub. 
     Accordingly, there is a need in the art for a hinge that will allow for interior mounting of a bathtub door during use but that also limits the encroachment of the door into the bathtub during ingress or egress. It is to the provision of such therefore that the present invention is primarily directed. 
     SUMMARY OF THE INVENTION 
     The present invention meets the need in the art with, in a preferred form of the invention, a bathtub hinge assembly for a walk-in bathtub having a bathtub surround, a door jamb, and a door. The bathtub hinge comprises at least one bathtub mounting block mounted to the exterior surface of the bathtub surround, at least one door mounting block mounted to the exterior surface of the bathtub door, and an articulating linkage coupled to the at least one bathtub mounting block and the at least one door mounting block. The articulating linkage includes at least one bathtub arm pivotally coupled to the at least one bathtub mounting block, and at least one door arm pivotally coupled to the at least one bathtub arm and pivotally coupled to the at least one door mounting block. 
     In another aspect, the present invention provides a bathtub hinge assembly comprising at least one bathtub mount and at least one door mount, with at least one first arm pivotally coupled to said at least one bathtub mount for both vertical movement and pivotal movement of said at least one first arm relative to said at least one bathtub mount, and at least one second arm pivotally coupled at one end to said first arm and pivotally coupled at an opposite end to said at least one door mount 
     In yet another aspect, the present invention also meets the need in the art with a method of door closure and opening for a walk-in bathtub that comprises the steps of: 
     providing a door for moving inwardly of a sidewall and threshold of a walk-in bathtub and outwardly for fitting against an interior surface of a jamb that defines a passage through the side wall; 
     hingedly mounting the door to a pair of bathtub mounts that mount to an exterior face of the side wall and a pair of door mounts that mount to an exterior face of the door, with a pair of articulating linkages that each pivotally connect to and between a respective bathtub mount and door mount; and
         interconnecting the hinged mounting with a first pivot rod between the pair of bathtub mounts, a second pivot rod between the articulating linkages, and a third pivot rod between the pair of door mounts, the first pivot rod movable relative to the bathtub mounts for vertical movement of the door. The door being movable on the hinged mounting inwardly and upwardly for then, upon pivoting of the door on the articulating linkages, passing outwardly of the side wall through the passage for bather ingress or egress through the passage.       

     Objects, advantages and features of the present invention will become readily apparent upon a reading of the following detailed description in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1 - 5    are a series of perspective views of a hinge assembly for a door of a walk-in bathtub embodying principles of the invention in a preferred form, and further illustrating the opening and closing operative sequence of the door hinge. 
         FIG.  1    illustrates a perspective view of a walk-in bathtub with a door having the hinge assembly according to the present invention, with the door in a closed position for sealing water within the walk-in bathtub for bathing. 
         FIG.  2    illustrates the walk-in bathtub with the door moved inwardly of a jamb and upwardly of a threshold that define a passage in a side wall of the bathtub. 
         FIG.  3    illustrates the walk-in bathtub with the door pivoted outwardly through the passage in the side wall and over the threshold portion of the door jamb. 
         FIG.  4    illustrates the door during continued outward opening movement of the door through the passage until the entire door is clear of the door jamb. 
         FIG.  5    illustrates the door further opened through continued pivoting movement to an open position for bather entry or egress though the passage in the side wall of the walk-in bathtub with a portion of the door cut-away to illustrate a portion of the hinge assembly. 
     
    
    
     DETAILED DESCRIPTION 
     With reference next to the drawings in which like parts have like identifiers, there is shown a hinge assembly  10  for a walk-in type bathtub according to the present invention. It is to be appreciated that the hinge assembly  10  shown in the drawings is configured for use with a walk-in type bathtub door D that fits against the interior surface of a door jamb J of a bathtub surround S. The door jamb J defines a door opening or pass-through O, as shown in  FIG.  4   , for a passage through which a bather enters and egresses the bathtub. A seal mounted to either the door D or jamb J aids in preventing water from passing therebetween when the door is in a closed position. The jamb J, door D and seal are well-known in the art and need not be disclosed further herein. 
     The walk-in bathtub conventionally includes a water inlet with selective hot and cold water supply, a drain, and a pump configured with a controller for selectively providing (i) hydrotherapy of pressurized water flow through side wall jets disposed for directing the jetted water against the legs, back and sides of a bather and (ii) microbubbles through the jets which keep bath water warm and further warms the bather&#39;s body and relaxingly stimulates the skin. Upon exiting the bath following a microbubble therapy, the warm feeling experienced by the bather persists as a relaxation and may improve sleep. The bathtub components of the water inlet, water supply, drain, and pump and controller, and operation of same, are well-known in the art and need not be disclosed further herein. 
     The hinge assembly  10  includes a pair of bathtub mounts, mounting blocks, supports, or members  12  that are mounted to the exterior facing surface  14  of the bathtub surround S adjacent to the door jamb J. The hinge assembly  10  also includes a pair of door mounts, mounting blocks, supports, or members  16  that are mounted to the exterior facing surface  17  of the door D. The bathtub mounting blocks  12  and door mounting blocks  16  may be made of any suitable material, such as a metal, plastic, polymer, or other material for a wet environment. 
     The hinge assembly  10  also includes articulating linkage  18  mounted to and extending between the bathtub mounting blocks  12  and the door mounting blocks  16 . The articulating linkage  18  has a pair of first or bathtub arms  22  pivotally coupled at a first end  24  to the bathtub mounting blocks  12 . The bathtub arms  22  are also pivotally coupled at oppositely disposed, second ends  26  to first ends  28  of a pair of second or door arms  30 . Each door arm  30  pivotally couples at an oppositely disposed second end  32  to one of the door mounting blocks  16 . 
     The first ends  24  of the bathtub arms  22  pivotally couple to the bathtub mounting blocks  12  through a first pivot rod  36 . The first pivot rod  36  passes through a first pivot rod mounting hole  38  within the bathtub mounting blocks  12  for both vertical movement of the first pivot rod  36  relative to the bathtub mounting blocks  12 , and for pivotal movement of the first pivot rod  36  relative to the bathtub mounting blocks  12  and the bathtub surround S coupled to the bathtub mounting blocks  12 . A spring  40  may be mounted about the first pivot rod  36  between the bathtub mounting block  12  and the bathtub arms  22  to force or bias the bathtub arms  22  upwardly relative to the bathtub mounting blocks  12 . The bottom end of the first pivot rod  36  has an enlarged end or stop  37  to limit the upward movement of the first pivot rod  36  and prevent the first pivot rod  36  from being removed from the bathtub mounting blocks  12 . 
     The second ends  26  of the bathtub arms  22  couple to the first ends  28  of the door arms  30  through a second pivot rod  44 . The second pivot rod extends between each of the bathtub arms  22  and each of the door arms  30 . The second pivot rod  44  allows for mutual pivotal movement of the bathtub arms  22  relative to the door arms  30 . 
     The second ends  32  of the door arms  30  couple to the door mounting blocks  16  through a third pivot rod  46 . The third pivot rod  46  allows for pivotal movement of the door arms  30  relative to the door mounting blocks  16  and the door D coupled to the door mounting blocks  16 . 
     The door D or surround S is provided with a conventional latch L that secures the door D to the surround S while also forcing the door D downwardly and toward the jamb J to maintain a proper watertight seal therebetween. Preferably, the latch L forces the door D downwardly against the biasing force of the spring  40  in the final movement of the door D against the door jamb J. The latch L may have a cam surface that moves the door inwardly against the seal. 
     In use, the door D may be moved from a closed position, shown in  FIG.  1   , to an open position, shown in  FIG.  5   , or visa-vera. With the door D is the closed position, shown in  FIG.  1   , the door D is forced against the interior surface of the door jamb J by the latch L to provide a watertight seal therebetween. 
     To open the door for egress or exiting from the bathtub T, the latch L is released and the door D is initially moved slightly inwardly into the bathtub T by pivoting of the door arms  30  relative to the bathtub arms  22  through the second pivot rod  44 , as illustrated by arrow A in  FIG.  2   . The release of the door D allows the biasing force of the spring  40  to vertically lift or raise the door D. This vertical movement of the door D is accomplished through the vertical movement of the first pivot rod  36  relative to the bathtub mounting blocks  12 , as illustrated by arrow B in  FIG.  2   . The vertical movement of the door D is necessary for the door D to pass over the threshold portion TP of the door jamb J at a later time during the door opening sequence. 
     Once the door D has been moved slightly into the interior space of the bathtub, the door D may commence to be pivoted outwardly and over the threshold portion TP of the door jamb J, as shown in  FIG.  3   . The door D is pivoted through the pivoting movement of the door arms  30  relative to the door mounting blocks  16  through the third pivot rod  46 , as illustrated by arrow C in  FIG.  3   . Thus, the now raised door D passes over or clears the threshold portion TP of the door jamb J. 
     The door arms  30  pivot about the second pivot rod  44 , as illustrated by arrow D in  FIG.  4   , and the bathtub arms  22  pivot about the first pivot rod  36 , as illustrated by arrow E in  FIG.  4   , to provide continued outward opening movement of the door D until the entire door D is clear of the door jamb J, as shown in  FIG.  4   . If further clearance or opening of the door is necessary, the door D may continue to be further opened through continued pivoting movement of the bathtub arms  22  relative to the bathtub mounting blocks  12 , as illustrated by arrow F in  FIG.  5   . 
     Once the door D is fully opened, the user may exit the bathtub T through the passage in the side wall or door opening  0  defined by the door jamb J. The door D is moved from its open position, shown in  FIG.  5   , to its closed position, shown in  FIG.  1   , through a reversing of the previously described sequence. 
     Thus, it should be understood that the present invention allows for an interior positioned door D to provide greater sealing capabilities, while also allowing the door D to be re-positioned outside the bathtub T to allow better ingress and egress from the bathtub T. 
     It should be understood that other types of door lifting or raising mechanisms may be used as an alternative to the spring  40  shown in the preferred embodiment, such as camming surfaces, ramps, hydraulic or pneumatic cylinders, or the like. 
     It should be understood that the latch L may be a cammed hook and pin type arrangement that pulls the door towards the door jamb upon movement of the hook. Alternatively, the latch may be a ramp or camming surface that moves the door down in a direction towards the door jamb upon manual movement of the door. Other similar type latches may also be used as an alternative. 
     It should be understood that as an alternative to the bathtub arms  22  moving vertically with respect to the bathtub mounting blocks  12 , other portions of the articulating linkage  18  may be adapted to move vertically. For example, the door mounting blocks  16  may move vertically with respect to the door arms  30 . 
     While this invention has been described in detail with particular reference to the preferred embodiment thereof and the best mode of practicing same for a movable door that seals for retaining water within a bathing tub yet opens conveniently for entry for bathing and egress, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described herein above and as set forth in the appended claims.