Abstract:
A push-up bra has an envelope between the front panel and the rear panel of the bra cups, that receives a flexible pouch containing a mixture of water and a hygroscopic agent such as 70% glycerine--30% water. The hygroscopic agent will draw moisture into the envelope preventing the volume of liquid from decreasing.

Description:
TECHNICAL FIELD 
     The present invention relates to an improved pad for a brassiere and, more particularly to a flexible, liquid filled envelope incorporated into a push-up bra. 
     BACKGROUND OF THE INVENTION 
     Brassieres are worn not only to provide support for women&#39;s breasts, but also to enhance the shape of the breasts within the brassieres, the portion of the breasts above the breasts and the cleavage between the breasts. 
     Push-up bras are designed to shape and elevate the breasts. Push-up bras usually contain a rubber pad received in a pocket in the lower front panels of the bra cups. The pad was formed by molding into a complex arcuate shape. Rubber pads were both stiff and uncomfortable. Rubber pads also caused insecurity due to straying of the pads. Other push-up bras used a more yielding silicone foam and some use Nylon (polyamide) padding to shape and lift. 
     Push-up bras with liquid filled envelopes have recently appeared on the market. Silicone oil liquids are very expensive and are hard to seal. Hydrocarbon oils have also been utilized as the liquid either alone or in a mixture with water. Hydrocarbons can attack the envelope. The liquids in the envelope are heated to body temperature of about 99° F. At this temperature, evaporation is increased and the hydrocarbon vapors can permeate through the wall of the envelope, creating offensive, unpleasant odors. Furthermore, water vapor is also able to permeate through the wall of the envelope decreasing the liquid volume in the envelope. The envelope could rupture or impact or when pierced by a sharp object causing embarrassment, discomfort and destruction of the pad. 
     
         ______________________________________List of References  Patentee          Patent No.______________________________________  Block, et al.          3,620,222  Kirby, et al.               3,845,507  Miller          5,235,974______________________________________ 
    
     STATEMENT OF THE PRIOR ART 
     Block, et al. discloses a foam, push-up brassiere pad. Kirby, et al. discloses a breast prosthesis to be worn inside a brassiere cup containing an inner bag. A jell-like liquid such as carboxymethyl cellulose is sealed within an outer bag containing air. Miller discloses an electrically heated bra for lactating mothers containing a fluid impermeable chamber filled with water. 
     STATEMENT OF THE INVENTION 
     The improved bra according to the invention contains a flexible envelope filled with a mixture of water and an odorless, organic hygroscopic agent in specified proportions providing no unpleasant aroma and little evaporation of water through the film of the envelope. The envelope is formed of a film of a tough synthetic resin resistant to puncture, preferably a thermoplastic resin capable of being heat-sealed. The film has low transmission rate for water vapor. The hygroscopic agent is able to drive water vapor from outside the envelope through the film into the envelope so that liquid volume is maintained. 
     The push-up bra of the invention looks and feels more natural and the bra eliminates discomfort and insecurity caused by stiff, sharp edged or straying inner pads. The inner cup lining adjacent the skin is soft and wicks moisture away from the skin. 
     These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is front view in elevation illustrating the push-up bra of the invention; 
     FIG. 2 is a view in section taken along line 2--2 of FIG. 1; and 
     FIG. 3 is a side view in elevation of a bra pad envelope. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIGS. 1 and 2, the push-up bra 10 of the invention is formed of two cups 12, 14, a stretchable strap with releasable fastener, not shown, and optional shoulder straps 16, 18. 
     The cups 12, 14 are formed of an outer layer 20 of fabric and an inner layer 22 of fabric. The outer layer 20 of fabric can be covered with a layer 25 of decorative material such as lace. The surface 24 of the inner layer 22 is preferably covered with a layer of a soft material 27 which absorbs and wicks moisture such as woven cotton or polypropylene cloth. A long narrow sleeve 26 following the curved outline of the bra cup can be formed along the lower periphery 29 of the bra cups 12, 14. A curved metal stiffening rod 28 is received in the sleeve 20 and inner layers 22 of each cup 12, 14. 
     The outer layers are stitched around their common peripheries 30, 32 to form pockets 34, 36 for receiving a flexible pouch 38, 40 containing a liquid 42 as shown in FIG. 2. The pouches 36, 40 have the general exterior shape of a bra cup 12, 14. The pouches 38, 40 are formed of a front film 42 heat sealed to a rear panel 44 forming a lip 46. The pouches 38, 40 are preferably anchored to the outer layer 20 or inner layer 22 of fabric. The lip 46 could be formed by adhering the outer peripheries of the two panels by adhesive or stitching. However, stitching or adhesive could make the lip 46 more susceptible to tear. It is preferred that the pouches 38, 40 be provided with an extended tab 50 which before thermal bonding serves as a filling spout. 
     The two layers 20, 22 of the pouch are completely thermal sealed within the tab 50 into a unitary film 52. Two thermally generated beads 54, 56 can be provided normal to the axis of the pouches to reinforce the tab from tearing. 
     The tab 50 is sewn 60 into the edge of the outer layer of fabric 20 near the outside periphery of the pocket 34, 36. The pouch 38, 40 is then inserted into the pockets 34, 36. The edge of the inner layer 22 of fabric is then stitched to the edge of the outer layer 20. 
     The skin of the pouch is a tough, puncture-resistant, flexible film such as a 0.01 to 5 mm thick film, preferably a film having a thickness from 0.05 to 0.5 mm. Suitable films are thermoplastic, thermally bondable films such as polyethylene, vinyl, silicone resins or polyurethane which can be in the form of a closed cell foam. The surface of the pouch has good wetability for water is resistant to hydrolysis, has flame retardence, U.V. It is stable to being agitated with hot soapy water in a washing machine. The film can have a Shore A Hardness from 50 to 100, a Specific Gravity of 1.1 to 1.3 an elongation of at least 300% and a minimum tear strength of 200 Lb/in. The film should have a high melting temperature above 180° C. in order to be capable of surviving temperatures encountered in washing and drying machines. However, hand washing and air drying of the bra are preferred. 
     The pouches are filled with a mixture of water and a major amount of an organic, hygroscopic material miscible with water. The mixture of water and the hygroscopic material forms a clear, uniform liquid having a viscosity similar to water. The organic hygroscopic materials are polyhydric organic compounds containing a plurality of hydroxyl group such as glycerine (glycerol) or liquid polyols. Glycerine is preferred since it is a clear, colorless, odorless syrupy liquid having hygroscopic properties. A USP grade having minimum purity of 99.5% is preferred. 
     Analysis of a USP glycerine used in the push-up bra of the invention follows: 
     
         ______________________________________TEST              RESULT    SPECIFICATION______________________________________Glycerine Content %             99.68     99.5 min.Relative Density 25/25                   1.2609                          1.2607 min.Color Apha                  5                           10 max.Ash                        &lt;0.01                          0.01 max.Chloride ppm              &lt;10                            10 max.Sulphate ppm              &lt;20                            20 max.Arsenic ppm                &lt;1.5                           1.5 max.Heavy Metal ppm        &lt;5         5 max.Chlorinated Compounds ppm                &lt;30         30 max.Fatty Acid &amp; Esters                  0.7     1.0 max.ml 0.5 NAOH______________________________________ 
    
     A prototype of the push-up bra of the invention was prepared by filling a polyurethane pouch with a mixture of 30% water and 70% USP glycerine. The tab on the pouch was heat sealed and then inserted into a pocket in a push-up bra. The tab was sewn into the periphery of the pouch and the seam on the inner layer of fabric was closed. 
     The film was a closed cell polyurethane having the following properties: 
     
         ______________________________________Properties______________________________________Color APHA            5Thickness                    0.1 mmHardness                      87 Shore ASpecific Gravity          1.20Tensile Strength          6525 psiElongation                  480%Tear Strength                 400 lb/inMelting Temperature         180-190° C.______________________________________ 
    
     The prototype was tested under normal wearing conditions. The mixture of water and glycerine provided a natural cushion. The pouch did not leak or ooze liquid. It was self sealing. There was no loss of volume over a 3 month test period due to permeation of water due to the glycerine humectant within the pouch. The bra was very comfortable for a shaping bra and gave a natural lift for a fuller look. Though the bra can be machine washed, there is less wear and tear if the bra is hand washed and hung to dry. 
     It is to be realized that only preferred embodiments of the invention have been described and that numerous substitutions, modifications and alterations are permissible without departing from the spirit and scope of the invention as defined in the following claims.