Fluid/foam filled seat bladder for occupant weight estimation

Abstract

A seat bladder has a closed volume that is at least partially filled with an open-cell or highly-reticulated foam material. The bladder fluid soaks into interstices in the foam material and fills the remaining bladder volume. The presence of the foam material reduces the time required to evacuate the bladder prior to fluid filling, and reduces the quantity of fluid required to fill the bladder. In subsequent usage, the foam material increases the restoring force of the bladder and the dissipation of energy input to the bladder.

1 . A seat bladder for estimating the weight of a seat occupant, comprising: 
 upper and lower sheets of elastomeric material joined by a peripheral seam to define a closed volume;    a sheet of foam material disposed between said upper and lower sheets of elastomeric material within said peripheral seam, said foam material defining a network of interconnected cells; and    a fluid disposed within said closed volume and substantially filling said network of interconnected cells.    
   
   
       2 . (canceled)  
   
   
       3 . The seat bladder of  claim 1 , further comprising: 
 at least one weld joining said upper and lower sheets of elastomeric material within said peripheral seam, said sheet of open cell foam material having an opening aligned with said weld so that said open cell foam material is not included in said weld.    
   
   
       4 . The seat bladder of  claim 1 , further comprising: 
 at least one weld joining said upper and lower sheets of elastomeric material within said peripheral seam, where said weld includes a region of open cell foam material intermediate the joined upper and lower sheets of elastomeric material.    
   
   
       5 . The seat bladder of  claim 4 , wherein said elastomeric material and said open cell foam material both comprise polyurethane.  
   
   
       6 . The seat bladder of  claim 1 , wherein said open cell foam material has a porosity in the range of about five pores per inch to about twenty pores per inch.  
   
   
       7 . The seat bladder of  claim 1 , wherein said fluid comprises silicone.