Abstract:
A slip-resistant floating bar soap having two outer convex-shaped layers of soap connected to an inner layer of concave-shaped rigid water-impermeable buoyant material having an exposed slip-resistant outer surface extending around the outer perimeter of the floating soap bar to provide a gripping surface for the hand of the user to aid in preventing the floating soap bar from slipping from the hands of the user.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to bar soap such as bath soap. More particularly, the present invention relates to bar soap which floats. 
     2. Description of the Related Art 
     When using bar soap to wash oneself or another object in a bathtub or other reservoir of water, the bar soap becomes slippery and can easily be dropped from the hands of the user. Common bar soap will then sink to the bottom of the tub of water. Retrieving the bar soap from the bottom of the bathtub or other body of water is often difficult, inconvenient and time-consuming. The slippery surface and sides of the bar soap contribute to the difficulty of grasping and retrieving the bar soap bar with the wet hand of the user. 
     Some floating soap bars have small air bubbles entrapped therein. Although such bars will float, the resulting soap bar will be less dense. Lower density of the soap will cause the soap bar to be depleted rapidly. 
     Exemplary of the related art are the following U.S. Pat. Nos. 6,555,509 B2; 5,869,437; 5,857,792; 5,221,506; 4,309,014; 4,277,358; 4,181,695; 4,062,792; 3,796,665; 3,413,230; 3,359,206; 3,293,684; 3,076,298; 2,988,841; 2,613,185; 1,083,571; and 821,245.  
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention there is provided a slip-resistant floating bar soap having two outer convex-shaped layers of soap connected to an inner layer of concave-shaped rigid water-impermeable buoyant material having an exposed slip-resistant outer surface extending around the outer perimeter of the floating soap bar to provide a gripping surface for the hand of the user to aid in preventing the floating soap bar from slipping from the hands of the user. 
     The floating bar soap of the invention has the advantage of floating rather than sinking when placed in a bathtub or other water reservoir. 
     The floating bar soap of the invention has the additional advantage of having a slip-resistant outer edge extending completely around the bar soap to reduce slipping of the bar soap from the hand of the user. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a perspective view of the floating bar soap of the invention; 
         FIG. 2  is a cross-sectional taken along lines  2 — 2  view of  FIG. 1 ; 
         FIG. 3  is a cross-sectional taken along lines  3 — 3  view of  FIG. 1 ; 
         FIG. 4  is a perspective view of two sheets of soap bars of the invention aligned for injection of buoyant material therebetween; 
         FIG. 5  is a perspective view of two sheets of soap bars of the invention after buoyant material has been injected therebetween; and  
         FIG. 6  is a perspective view of the buoyant material injected between to layers of soap. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, in  FIGS. 1–3  the floating bar soap of the invention is generally indicated by the numeral  10 . Floating bar soap  10  has two outer layers generally indicated by the numerals  12  and  14  made of soap having a specific gravity of greater than one and an inner layer shown in  FIGS. 1–3  and  6  generally indicated by the numeral  16  made from a buoyant material having a specific gravity of less than one. Outer layers  12  and  14  are generally rectangular in shape at the outer edges thereof. If desired, the outer edges of outer layers  12  and  14  could be a straight line. 
     Soap layers  12  and  14  are made from common bath soap well known in the art. Such common bath soap has a specific gravity of greater than one and therefore will not float on water. Soap layers  12  and  14  are preferably substantially identical in size and shape. Soap layer  12  has a convex outer surface  12   a  and an opposite convex inner surface  12   b , and soap layer  14  has convex outer surface  14   a  and an opposite convex inner surface  14   b.    
     Located between soap layers  12  and  14  is buoyant layer  16 . Buoyant layer  16  must be rigid, water-impermeable, and have a specific gravity of less than one. Buoyant layer  16  has concave opposite outer surfaces  16   a  and  16   b  which contact and receive the convex inner surfaces  12   b  and  14   b  of soap layers  12  and  14 . Receipt of the convex inner surfaces  12   b  and  14   b  of soap layers  12  and  14  in the concave outer surfaces  16   a  and  16   b  of buoyant layer  16  to which they are bonded  increases the horizontal shear force necessary to separate two adjacent layers  12  and  16 , or  14  and  16 , of bar soap  10 . 
     Buoyant layer  16  has outer edges  16   c  which provide an exposed gripping surface on the outer edges of floating soap bar  10  for grasping or gripping by the hand of the user of floating bar soap  10  to aid in preventing floating soap bar  10  from sliding or slipping from the hand of the user. As shown in  FIGS. 1 ,  5 , and  6 , outer edges  16   c  of buoyant layer  16  are preferably generally rectangular in shape. 
     Preferably the maximum thickness or height of outer edges  16   c  of buoyant layer  16  is from about one-fourth to about one-half of the maximum vertical thickness of the floating soap bar  10  shown in  FIGS. 1–3  to provide an adequate gripping surface area for the user of floating soap bar  10 . Preferably, the thickness of buoyant layer  16  at the midpoint between opposite outer edges  16   c  is about one-eighth to about one-fourth of the maximum vertical thickness of the floating bar soap  10  shown in  FIGS. 1–3  to insure an adequate degree of concavity to maximize the volume of soap in outer layers  12  and  14  of floating bar soap  10  and to increase the shear force necessary to separate outer layers  12  and  14  from buoyant layer  16 . 
     Buoyant layer  16  is preferably made from a water-impermeable foamed low density closed-cell polymeric material having a specific gravity of less than one. Exemplary of such foamed polymeric materials well known in the art are foamed polystyrene, polyurethane, and the like. Foamed polystyrene is preferred. 
     As shown in  FIGS. 4 and 5 , a preferred method of making the floating bar soap  10  of the invention includes molding, pressing, and/or stamping two substantially identical sheets generally indicated by the numerals  13  and  15  of soap layers  12  and  14 , with individual soap layers  12  in sheet  13  being joined at their peripheral edges and individual soap layers  14  in sheet  15  also being joined at their  peripheral edges. The inside surfaces of each sheet  13  and  15  may be textured to improve bonding between soap layers  12  and  14  and the buoyant layer  16 . By texturing is meant that small irregularities or depressions are molded in the inside surfaces of individual soap layers  12  and  14  in sheets  13  and  15 . The size of each sheet  13  and  15  will be selected to eliminate sagging of the sheets when supported at their edges. 
     The outer surface of each sheet  13  and  15  may be molded or stamped to include a brand name or logo. The convex, sloping outer surface of floating bar soap  10  provides a shape that is more easily held in the hand of the user. 
     Sheets  13  and  15  are aligned as shown in  FIG. 4  and held apart to form a space between sheets  13  and  15  ranging from one-eighth to one-fourth of the total thickness of floating bar soap  10 , and a water-impermeable foamed low density closed-cell polymeric material having a specific gravity of less than one is injected between sheets  13  and  15 . Preferably, the water-impermeable foamed low density closed-cell polymeric material is polystyrene. 
     After the water-impermeable foamed low density closed-cell polymeric material has fully expanded and hardened to form buoyant layer  16  between sheets  13  and  15 , the individual soap bars  10  will be separated by a band saw with multiple blade, piano wire saw with multiple wires, or other apparatus known in the art. 
     Floating bar soap  10  has a specific gravity of less than one and preferably a thickness of about one inch. Preferably, floating bar soap  10  is generally rectangular in shape and is from two to three inches in width and three to four inches in length. If desired, floating bar soap  10  could be generally elliptical or oval in shape. 
     Although the preferred embodiments of the invention have been  described in detail above, it should be understood that the invention is in no sense limited thereby, and its scope is to be determined by that of the following claims: