Abstract:
A method is provided for making a bra pad having a rigid foam that is thickest at the bottom of the pad for hidden support and a stretchable softer foam for comfort and universal fit throughout the entire pad. The method includes pre-laminating rigid and stretchable foam sheets with fabric and shaving the foam sheets. The rigid foam sheet is shaved so that it has a V-shaped recess and a gradually sloped interface between the V-shaped recess and remainder of the sheet. The stretchable foam sheet is shaved so that it has a pair of elevated areas. Then, the top surfaces of the shaved foam sheets are affixed together to form a pre-form assembly and the pre-form assembly is molded under heat. The pair of pads are then trimmed out.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
   The present invention relates generally to the field of bras and related garments and in particular to a new and useful pad product having a combination of rigid and stretch foam and varying thickness for use in bras, camisoles, slips or any other breast covering garment where padding is desired. 
   Pads typically contain at least one layer of cushioning material such as foam or fiberfill. Some pads also have more than one layer of cushioning material, such as those described in Published U.S. Patent Application 2003/0181129 A1, U.S. Pat. No. 6,811,464, U.S. Pat. No. 6,805,610, and U.S. Pat. No. 2,673,981. 
   U.S. Pat. No. 5,967,877 combines a foam pad with a support rib along the lower edge portion of the pad. The rib is described as a thin strip of polyurethane foam or other foam-like material. 
   In addition, U.S. Pat. No. 2,563,241 and U.S. Pat. No. 2,834,352 to Ullian describe bra pads having varying thicknesses. 
   Still, there is a need for a pad that can provide hidden support without the need for visible ribs or other uncomfortable support devices. Furthermore there is a need for balancing comfort and support at pre-determined locations while maintaining a universal fit. Finally, there is a need for a method for making such a pad. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a method of manufacturing a bra pad which balances both comfort and hidden support at vital pre-determined areas while maintaining a universal fit. 
   It is a further object of the invention to provide a bra pad made in accordance with the method of the invention. 
   Accordingly, a method is provided for making a bra pad having a rigid foam that is thickest at the bottom of the pad for support and a stretchable softer foam for comfort and universal fit throughout the entire pad. The contour of the pad has variations in thickness for balancing comfort and support in pre-determined areas. 
   The method includes the steps of pre-laminating rigid and stretchable foam sheets, shaving the sheets, affixing the top surfaces of the shaved foam sheets together to form a pre-form assembly, molding the pre-form assembly under heat, and trimming the final pad into the shape of a cup. The rigid sheet is shaved so that it has a V-shaped recess and a gradually sloped interface between the V-shaped recess and remainder of the sheet. The stretchable sheet is shaved so that it has a pair of elevated areas. 
   The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
       FIG. 1  is a perspective top and front view of a pre-laminated rigid foam assembly; 
       FIG. 2  is a perspective top and front view of a pre-laminated stretchable foam assembly; 
       FIG. 3  is a perspective top and front view of a shaved pre-laminated rigid foam assembly with a V-shaped recess on the top surface; 
       FIG. 4A  is a schematic diagram of the mold assembly for shaving the pre-laminated rigid foam assembly; 
       FIG. 4B  is a side view of the lower mold portion of the mold assembly; 
       FIG. 4C  is a top perspective view of the lower mold portion of the mold assembly; 
       FIG. 5  is a schematic diagram of the mold assembly and shaving apparatus for shaving the pre-laminated rigid foam assembly; 
       FIG. 6  is a schematic diagram of the operation of the shaving apparatus with the mold assembly for shaving the pre-laminated rigid foam assembly; 
       FIG. 7  is a perspective top and front view of a shaved pre-laminated stretchable foam assembly with a pair of elevated areas on the top surface schematically designated by two circles; 
       FIG. 8  is a schematic diagram of the mold assembly for shaving the pre-laminated stretchable foam assembly; 
       FIG. 9  is a schematic diagram of the mold assembly and shaving apparatus for shaving the pre-laminated stretchable foam assembly; 
       FIG. 10  is a schematic diagram of the operation of the shaving apparatus with the mold assembly for shaving the pre-laminated stretchable foam assembly; 
       FIG. 11  is a side view of the shaved stretchable foam assembly of  FIG. 7 ; 
       FIG. 12  is a top and front perspective view of the pre-form assembly; 
       FIG. 13  is a side view of the molded pre-form assembly with the locations of the V-shaped recess and interface of the shaved rigid foam and elevated areas of the shaved stretchable foam designated by dashed lines; 
       FIG. 14  is a top view of the final pads after the molded pre-form assembly is trimmed; and 
       FIG. 15  is cross-section of the pad showing the layers of rigid and soft foam. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements,  FIG. 1  shows an assembly generally designated  10  formed in the first step of the present invention by laminating a sheet of fabric  13  to the bottom surface of a rigid sheet of foam  11 . Laminating is accomplished by conventional means such as gluing. The sheet of foam  11  and the sheet of fabric  13  are co-extensive. The rigid sheet of foam  11  is preferably polyurethane foam having a density between 45 and 55 kg/m 3  and a hardness between 43–57 N. Although polyurethane foam is preferred, any thermoplastic foam material can be used according to the present invention, and in fact any formable material can be used which is capable of being formed into a permanent yet resilient three-dimensional shape, having a density and hardness in the range described above. 
     FIG. 2  shows an assembly generally designated  20  in which a stretchable sheet of foam  21  is laminated with a sheet of fabric  23  on its bottom surface. The sheet of foam  21  and the sheet of fabric  23  are co-extensive. The stretchable sheet of foam  21  is preferably polyurethane foam having a density between 39 and 47 kg/m 3  and a hardness between 80 and 95 N. Although polyurethane foam is preferred, any thermoplastic foam material can be used according to the present invention, and in fact any formable material can be used which is capable of being formed into a permanent yet resilient three-dimensional shape, having a density and hardness in the range described above. 
   In the next step, the rigid sheet of foam  11  is shaved to produce a sheet of shaved foam  15  having a “V” shaped recess  17  as shown in  FIG. 3 . An interface region  16  gradually slopes upward from the V-shaped recess  17  to the remainder of the shaved foam  15  surface. The sheet of shaved foam  15  is formed by the following process. 
     FIG. 4A  shows a shaving mold generally designated  31  comprising an upper shaving mold portion  33  and a lower shaving mold portion  35  with a thickness of e.g. 12 mm rigid polyurethane foam  11  therebetween. The shaving mold halves or portions  33  and  35  can be made of wood, plastic, metal or other suitable rigid material. As illustrated in  FIGS. 4B–4C , lower mold half  35  contains an extended or raised member  37  on its upper surface which gradually rises at a region  38 . 
     FIG. 5  illustrates the shaving mold in its closed position with the resilient formable sheet of material  11  pressed down onto the lower mold half so that some of the material of sheet  11  is pressed against the raised member  37  and is therefore indented with the raised member  37  in the center. A thickness of material, for example at  39 , remains above the raised member  37  of the lower shaving mold half  35 . 
   A shaving apparatus generally designated  41  is also illustrated in  FIG. 5  which comprises a movable carriage  43 , which carries a blade, knife or shaving member  45  that extends transversely the full width of material sheet  11  (perpendicular to the plane of  FIG. 5 ). Blade  45  is also positioned intermediate to the upper and lower shaving mold halves  33 ,  35  respectively so that a portion of the layer  39  can be neatly shaved from the sheet  11 . For this purpose, member  45  may be heated (e.g., a cutting wire), may be mounted for movement like a band saw, may be reciprocally vibrated back and forth like an electric knife or oscillated in any other appropriate way for cutting the foam material of sheet  11 . 
   With the shaving apparatus  41  activated to vibrate, heat or otherwise activate member  45 , the carriage  43  is moved in the direction of arrow A and across the sheet  11  until it reaches its final position shown in  FIG. 6 . In this position a slice  47  has been made in sheet  11  thus achieving the shaving effect.  FIG. 3  shows the shaved component  15  which is removed from the shaving mold after it is opened and which contains a V-shaped recess  17  surrounded by thicker material area  19 , and an area of graduated thickness  16  between the recess  17  and remaining thicker area  19  of the shaved component. 
   In the next step, the stretchable sheet of foam  21  is shaved to produce a sheet of shaved foam  25  having a pair of elevated areas  27  as schematically shown in  FIG. 7  by two circles. The shaved sheet of foam  25  is formed by the following process. 
     FIG. 8  shows a shaving mold generally designated  51  comprising an upper shaving mold portion  53  and a lower shaving mold portion  55  with a thickness of e.g. 9 mm stretchable polyurethane foam  21  therebetween. The shaving mold halves or portions  53  and  55  can be made of wood, plastic, metal or other suitable rigid material. Lower mold half  55  contains a pair of recesses  57  in its upper surface. 
     FIG. 9  illustrates the shaving mold in its closed position with the resilient formable sheet of material  21  pressed down onto the lower mold half so that some of the material of sheet  21  is pressed into each recess  57  but also a thickness of material, for example at  59 , remains above the recesses  57  of the lower shaving mold half  55 . 
   A shaving apparatus generally designated  41 , as also described above in  FIGS. 5–6 , is illustrated in  FIG. 9 . The shaving apparatus  41  comprises a movable carriage  43 , which carries a blade, knife or shaving member  45  that extends transversely the full width of material sheet  21  (perpendicular to the plane of  FIG. 9 ). Blade  45  is also positioned intermediate to the upper and lower shaving mold halves  53 ,  55  respectively so that a portion of the layer  59  can be neatly shaved from the sheet  21 . For this purpose, member  45  may be heated (e.g., a cutting wire), may be mounted for movement like a band saw, may be reciprocally vibrated back and forth like an electric knife or oscillated in any other appropriate way for cutting the foam material of sheet  21 . 
   With the shaving apparatus  41  activated to vibrate, heat or otherwise activate member  45 , the carriage  43  is moved in the direction of arrow A and across the sheet  21  until it reaches its final position shown in  FIG. 10 . In this position a slice  47  has been made in sheet  21  thus achieving the shaving effect.  FIGS. 7 and 11  show the shaved component  25  which is removed from the shaving mold after it is opened and which contains a pair of elevated areas  27  of thicker material, surrounded by thinner material areas  29 . 
   Although sheets of foam  11  and  21  were pre-laminated in a previous step with respective fabrics  13  and  23 , the lamination may optionally be done following the shaving of the sheets, wherein the fabric would be laminated to the bottom of the rigid or stretchable shaved foam sheet while the top of the rigid or stretchable shaved foam sheet has a recess or a pair of elevated areas respectively. 
   Then the top surface of the shaved sheet of foam  15  is affixed to the top surface of the shaved sheet of foam  25  via conventional means such as glue producing a pre-form assembly generally designated  61 . The laminated fabrics  13  and  23  of the respective foam sheets remain on the outside of the assembly  61  while the shaved foams  15  and  25  are sandwiched therebetween as shown in  FIG. 12 . The V-shaped recess on the top of the rigid shaved foam sheet  15  faces the pair of elevated areas on the top of the stretchable shaved foam sheet  25 . Shaved foam sheet  15  will form the outer or front portion of the pad away from the user and the shaved foam sheet  25  will form the inner or rear portion of the pad closest to the user. 
   A molding having male and female members compresses the assembly  61  for approximately 140 seconds at approximately a temperature of 190° to 210° Celsius, forming cup shapes  71  and  73  in the assembly  61  having a top thin area  75  corresponding to the region of the V-shaped recess  17  of the foam  15  (shown above a first dashed line  111 ), a bottom thick area  77  corresponding to the thicker area  19  of the shaved foam  15  (shown below a second dashed line  113 ), and a middle area  79  having graduated thickness corresponding to the graduated thickness interface area  16  of the foam  15  (shown between dashed lines  111  and  113 ), as shown in the diagram in  FIG. 13 . Furthermore, a pair of dashed circles  115  designate a region of the final pad corresponding to the region where the elevated areas  27  of the foam  25  overlap the graduated area  16  of the foam  15 . The mold also presses and forms an area  78  below the cup shapes. 
   In the last step, final pads  81  and  83  are trimmed in the shape of cups shown in  FIG. 14 . Each pad has fabric attached on the front corresponding to the fabric  13  that was earlier laminated to the foam sheet  11  or shaved foam sheet  15 . Each pad also has fabric attached to the rear of the pad corresponding to the fabric  23  that was earlier laminated to the foam sheet  21  or shaved foam sheet  25 . Flanges  85  extend from the bottom portion of the pads and correspond to the area  78  pressed by the mold above. 
   An approximate cross-section of a final pad is shown in  FIG. 15 . A dashed line separates the rigid foam section  91  from the stretchable foam section  93 . The pad is thicker at the bottom area corresponding to the location of the thicker area  19  of shaved foam  15 . More thick rigid foam is provided in this area for providing hidden support. The pads are thinnest at the top area of the pad corresponding to the region of the V-shaped recess  17  of the foam  15 . More stretchable foam and less rigid foam is provided in this area for providing comfort and universal fit. 
   Also, thick areas (not shown) are provided in the center of the pads corresponding to the region where the elevated areas  27  of the foam  25  overlap the graduated area  16  of the foam  15 . 
   While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.