Water pad

Abstract

A water pad is disclosed to include a closed fluid impervious flexible envelope, which defines therein a closed chamber and has a pressure inside within the range from a negative to balance with the atmospheric pressure, a soft, elastic inner pad, which is accommodated in the closed chamber inside the closed fluid impervious flexible envelope, said inner pad has open cells, a fluid filled in the open cells in the inner pad, and a buffering space defined within the closed chamber inside the closed fluid impervious flexible envelope around the inner pad for receiving the fluid when the fluid is forced out of the inner pad upon a force of the external pressure. The water pad can be made in different forms for use as hot/cold compress pad, seat cushion, water mattress, medical mattress, warm-keeping pad, mouse pad, etc.

1 . A water pad, comprising: 
 a closed fluid impervious flexible envelope, said closed fluid impervious flexible envelope defining therein a closed chamber and having a pressure inside within the range from a negative to balance with the atmospheric pressure,    an inner pad made out of a soft and elastic material and accommodated in the closed chamber inside said closed fluid impervious flexible envelope, said inner pad having a plurality of open cells;    a fluid filled in the open cells in said inner pad; and    a buffering space defined within said closed chamber inside said closed fluid impervious flexible envelope for receiving said fluid when said fluid is forced out of said inner pad upon a force of the external pressure.    
   
   
       2 . The water pad as claimed in  claim 1 , wherein said closed fluid impervious flexible envelope is made out of polymers.  
   
   
       3 . The water pad as claimed in  claim 1 , wherein said inner pad is made out of one of the materials of sponge or foamed materials.  
   
   
       4 . The water pad as claimed in  claim 1 , wherein said fluid is water containing an anti-freezing agent.  
   
   
       5 . The water pad as claimed in  claim 1 , wherein said buffering space is below the topmost elevation of said inner pad when pressure inside is negative.  
   
   
       6 . The water pad as claimed in  claim 1 , wherein said fluid has a fluid level within 0.5 cm above the elevation of the topmost side of said inner pad when pressure inside is balanced with atmospheric pressure.  
   
   
       7 . The water pad as claimed in  claim 1 , wherein said buffering space is sufficient to receive said fluid that flows out of said inner pad without causing the water pad to expand and to become hard when the water pad supports a force of the external pressure.  
   
   
       8 . The water pad as claimed in  claim 1 , wherein said buffering space is defined within said closed fluid impervious flexible envelope around said inner pad.  
   
   
       9 . The water pad as claimed in  claim 1 , wherein said buffering space is formed of holes and grooves on said inner pad.  
   
   
       10 . The water pad as claimed in  claim 1 , wherein said inner pad has a plurality of holes and grooves, forming said buffering space.  
   
   
       11 . The water pad as claimed in  claim 1 , wherein the amount of said fluid is within 85%˜120% relative to the volume of said inner pad.  
   
   
       12 . The water pad as claimed in  claim 1 , wherein said closed fluid impervious flexible envelope is made out of one of the materials including TPU (Thermoplastic Polyurethane), SBR (Styrene-butadiene rubber), PU (Polyurethane) foam, and SB (Styrene-butadiene) foamed rubber.  
   
   
       13 . The water pad as claimed in  claim 1 , wherein said inner pad is made out of one of the materials of PU (Polyurethane) foam and SB (Styrene-butadiene) foamed rubber.