Patent Document

CROSS-REFERENCE TO RELATED APPLICATION 
     Not applicable. 
     STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to seats mountable on toilets, bidets and the like. In particular it relates to such seats which have been modified for improved comfort, and provided with structures permitting customization of the seat. 
     A wide variety of toilet seats have been developed, typically in the form of rings with central holes, or horseshoe shaped structures with the opening of the horseshoe projecting forward. Many of the earlier toilet seats were made of wood or another hard material. Later seats were made of hard plastics. While these seats provided good support, they could be uncomfortable when used for an extended period, or when used by particularly sensitive individuals. 
     As a result the art developed a variety of cushioned toilet seats. Some of these were made of a single material which had considerable give in it to provide a mattress-like feel. However, those seats could be structurally somewhat weak. Further, they often would deform after prolonged periods of use. 
     The art also developed a variety of toilet seats made of multiple materials (e.g. one cushioning material and one material providing structural integrity). These multiple material seats provided some cushioning, while still permitting improved structural integrity. 
     Examples of such mixed material toilet seats include U.S. Pat. Nos. 1,206,186, 1,208,869, 1,829,526, 1,863,799, 2,155,286, 2,160,100, 2,185,499, 2,771,612, 3,379,800, 3,513,050, 3,623,931, 3,639,922, 3,845,183, 3,863,277, 3,949,432, 3,988,789, 4,085,468, 4,155,127, 6,154,892, and 6,748,611. See also U.S. patent application publications 2003/0121090 and 2003/0121091. 
     A variety of considerations come into play when designing a mixed material toilet seat. A particularly decorative exterior material may be unsuitable for use in a water environment as being subject to degradation. Also, desirable external materials may be relatively expensive, thus leading one to want to minimize the thickness of the external layer using that material. 
     Another concern is the overall weight of the seat. It is generally true that the heavier the seat, the greater the noise that occurs when the seat accidentally drops down onto the toilet (absent a dampering system), and the greater risk of damaging the toilet base when that occurs. Further, the more material that is used to form the seat, the greater the material cost. 
     Apart from these issues the optimal contact feel for one portion of the body (i.e., one&#39;s rear end) may be quite different from the optimal contact feel along another portion of the body (i.e., one&#39;s rear thigh). This may have significant comfort implications, particularly for someone suffering from arthritis or another condition providing unusual sensitivity. 
     Hence, further improvements are desired in connection with designing toilet seats. 
     SUMMARY OF THE INVENTION 
     In one aspect the present invention provides a plumbing fixture seat suitable for attachment to a plumbing fixture. The seat has an upper cushion with an upper surface and radially outer and radially inward edges depending downward from the upper surface. There is also a lower base having a catch, at least a portion of the lower base being made of a material that is more rigid than at least a portion of the upper cushion. One of the edges is snapped into the catch to thereby assemble (preferably removably assembled) the upper cushion to the lower base. Preferably the catch is an undercut along the base. 
     In the most preferred forms the lower base can have a radially outer undercut and also a radially inner undercut, and both the radially outer and radially inner edges of the upper cushion have been snapped into respective undercuts of the lower base. A toilet seat or the like can thereby be formed. 
     The particular material selected for the upper cushion is not critical. It is highly preferred that it provide a somewhat cushioning feel while being able to withstand the environment to which it will be exposed. Examples of suitable materials are ethyl vinyl acetate, polypropylene and polythiourethane. 
     Similarly, the material selected for the base is not critical. However, since an important purpose of the base is to provide rigidity, the base should preferably be made of a material that is more rigid than a part of (preferably all of) the cushion. We prefer a grade of polypropylene for this purpose that has a high durometer. 
     A construction where the base and cushion can be removably snap fit together permits a single form of base to be used with multiple cushion types. This has some value at the factory (e.g. in reducing the number of SKU parts while still allowing a variety of different cushioned seats). 
     Further, if a single base is sold with multiple cushion elements the toilet seat can be converted by the consumer. For example, if someone prefers more support when they first purchase the seat, and then changes what they believe to be optimal (e.g. they lose a lot of weight), the consumer can at the home change the seat. 
     Still further customization is possible with the present invention. This can be achieved if the cushion is formed with different zonal regions of different hardness. Thus, the upper cushion may have a plurality of zones, a first of the zones being formed from a first material having a first maximum durometer, and a second of the zones being formed from a second material having a second maximum durometer higher than the first maximum durometer. 
     Thus, for example, the portion of the cushion adjacent the buttocks can be very soft, the portion adjacent the thigh can be of the same zone, or of a separate zone that is somewhat harder, and the remainder of the seat cushion can be even harder. This can maximize comfort for each individual, as different styles can be offered. 
     Still further customization is possible if the zones are separately formed, and can be separately snapped on to the base. With such a structure at least one of the zones could be separately replaced if optimal feel has changed for only one region. 
     To provide a different cushioning feel the upper cushion can have at least one leg positioned between its outer and inner edges that rests on an upper surface of the lower base. It provides more support than just an air pocket. However, as there is an air cavity between the lower base and the upper cushion on each side of the leg, the weight of the design is lower. 
     Alternatively, the lower base and the upper cushion can contact each other in a close complementary fashion along a curved surface, such that one bulges into the other. This further solidifies the linking of the cushion and base, while maximizing the support. 
     In another aspect the invention provides a plumbing fixture seat suitable for attachment to a plumbing fixture where there is an upper cushion and a lower base attached to the upper cushion. The upper cushion comprises a plurality of zones, a first of said zones being formed from a first material having a first maximum durometer, and a second of said zones being formed from a second material having a second maximum durometer higher than the first maximum durometer. This is so regardless of the means of attaching the base to the cushion, albeit (as noted above) it is preferable that the base and cushion be removably linked. 
     In yet another form the invention provides a kit for producing a customized toilet seat. There is a lower base and a plurality of separable cushion elements that when mounted on top of the lower base are capable of forming an upper cushion for a toilet seat. The upper cushion then has a series of zones, at least one of which has a different maximum durometer than at least one of the other zones of the cushion. 
     In still another form of the invention the seat has an upper cushion having an upper surface and radially outer and radially inward edges depending downward from said upper surface. The upper cushion also has at least one leg positioned between said outer and inner edges. There is a lower base assembled to the upper cushion such that the leg rests on an upper surface of the lower base with an air pocket on two sides thereof. 
     It should be appreciated that the present invention provides a cushioned plumbing fixture seat with structural integrity, and with improved ability for customization. 
     These seats are inexpensive to manufacture using standard molding techniques. For example, injection molding can make the polypropylene base and also the cushion can be an injection molded ethyl vinyl acetate. After formation these parts can be assembled quite quickly (even by a consumer). Further, they permit seats of reduced weight which can still perform the needed functions of the seat, thereby reducing costs and the risk of bowl damage. 
     These and still other advantages of the present invention will be apparent from the detailed description and drawings. What follows are merely preferred embodiments of the present invention. To assess the full scope of the invention the claims should be looked to. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of a plumbing fixture seat of the present invention in the form of a toilet seat; 
         FIG. 2  is a partial sectional and partial side view taken generally along line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a view similar to  FIG. 1 , but of a second embodiment; 
         FIG. 4  is a partial sectional and partial side view similar to  FIG. 1 , albeit taken generally along line  4 - 4  of  FIG. 3 ; 
         FIG. 5  is another view similar to  FIG. 1 , but of a third embodiment, and with a portion broken away; 
         FIG. 6  is a partial sectional and partial side view similar to  FIG. 1 , albeit taken generally along line  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a partial sectional and partial side view similar to  FIG. 1 , albeit of a fourth embodiment; 
         FIG. 8  is a partial sectional and partial side view similar to  FIG. 1 , albeit of a fifth embodiment; 
         FIG. 9  is a partial sectional and partial side view similar to  FIG. 1 , albeit of a sixth embodiment; 
         FIG. 10  is a partial sectional and partial side view similar to  FIG. 1 , albeit of a seventh embodiment; 
         FIG. 11  is a partial sectional and partial side view similar to  FIG. 1 , albeit of an eighth embodiment; 
         FIG. 12  is a partial sectional and partial side view similar to  FIG. 1 , albeit of a ninth embodiment; and 
         FIG. 13  is a view similar to  FIG. 3 , albeit of another embodiment with different zonal regions. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring first to  FIGS. 1 and 2 , a toilet seat  10  has an upper cushion  12  connected to a supporting lower base  14 . The rear of the cushion  12  can be formed with cylindrical bores  13  to accept conventional hinge posts. Alternatively, the base could be formed with the bores to accept the hinge post (not shown). 
     The cushion  12  is a molded synthetic material that can compress somewhat when sat upon and thereby provide a cushiony feel. It is preferably formed with an upper generally flat seating surface  16  and an opposing underside  18 . In one form the underside  18  includes a series of downwardly protruding feet  20  spaced apart from each other but substantially surrounding the central hole  11 . The feet  20  thereby define individual cavities/air pockets  22 . 
     The cushion  12  also comprises a outward radial edge  24  that extends downwardly from the upper surface  16  of the cushion  12  and includes an essentially hook-like flexible flange  26 . The cushion may also have a radially inwardly edge  28  that also has another hook-like flexible flange  30 . 
     The base  14  is preferably in the form of a substantially rigid slab with an upper surface  32 , an underside  34 , and opposing radially inward and radially outward undercuts  38  and  40 . The flanges  26  and  30  can snap into the undercuts to connect the cushion  12  with base  14 . 
     Once assembled, the downwardly protruding feet  20  of the cushion  12  rest directly on upper surface  32  to provide support. The channels  22  defined between the protruding feet  20  lighten the weight of the fixture seat  10 , while also allowing some flexing of the feet if the pressure becomes too great. 
     The dotted lines in  FIG. 2  (and also those in FIGS.  4  and  6 - 12 ) illustrate potential further bumper members that may be integral with, or linked to, the base. However, those structures are not critical to practicing the invention. 
     Referring next to  FIGS. 3-4 , a second embodiment of the plumbing fixture  10  of the present invention is shown. Similar parts are similarly numbered with respect to this embodiment, and with respect to the other embodiments. Note that here there is only one undercut  40 , on the radially inward side. 
     The cushion  12  in  FIG. 3  is comprised of various zones  42  along the circumference. Preferably, the rear zone  43  is made of a more flexible material than the zones  45 . In any event, these zones can be selected from materials such as ethyl vinyl acetate, polypropylene, or polythiourethane. Other plastic and synthetic materials may also be selected which have a cushiony feel plus the other desired characteristics for the environment. 
     Referring next to  FIGS. 5 and 6 , the form of snap fit connection is slightly different because of the less slab-like nature of the base. Groove  44  shows that some weight can be reduced in this configuration. 
     As seen in  FIG. 7  the air pockets can be removed, and if desired a convex/concave contact relationship can be between the contacting surfaces of the base and cushion. Here, the base bulges into the cushion. In contrast, as seen in  FIG. 8 , the cushion can instead bulge into the base. 
     In  FIG. 9 , there is a base  14 A having a substantially concave upper surface  32 A and an underside  34 A, and an insert  14 B, having a upper surface  32 B and a convex underside  34 B. The underside  34 A of the base  14 A includes an edge  36 A having an undercut  40 A that matingly engages with the flange  26  of the cushion  12 . There is also an undercut  38 A that engages flange  30  of the cushion  12 . Hence, instead of relying on an air pocket to alter cushion feel, a customizable insert element  14 B can be provided, and changed over time, without the need to alter the base or cushion. 
     In  FIG. 10 , the concept is similar except that there is no insert and only an air pocket  46  to provide interim support. 
     In  FIG. 11 , the base has an undulating upper surface which provides limits to the degree of deformation of the cushion, than in  FIG. 10 . 
     In  FIG. 12 , a slightly different base structure is shown, and the complementary cushioning has a corresponding shape. 
     In  FIG. 13  we show another embodiment  50  where the zonal regions  51  and  52  extend along the thigh area and part of the buttocks area, rather than simply being defined by radial severing lines. 
     It should be appreciated that preferred embodiments of the invention have been described above and depicted in the enclosed drawings. However, many modifications and variations to the preferred embodiments will be apparent to those skilled in the art, which will be within the spirit and scope of the invention. For example, while the invention has been depicted in the context of a toilet seat, it could also be used for a seat for other plumbing fixtures. The invention could be in the form of a bidet seat, a seat associated with a bath tub, or serve another seating purpose associated with plumbing fixtures. 
     Therefore, the invention should not be limited to just the described embodiments. To ascertain the full scope of the invention, the following claims should be referenced. 
     INDUSTRIAL APPLICABILITY 
     The invention provides plumbing fixture seats, such as toilet seats, which can be customized.

Technology Category: 1