Inflatable knee bolster

An expansible knee bolster for a vehicle occupant that is projected outwardly from a stored position to an extended position adjacent the occupant's knees by inflation of an expansible chamber by an inflator during a collision event, said knee bolster comprising:

• a hollow enclosure of multipiece construction having a face portion including a peripheral edge, a separate three dimensional expansible body portion joined to said face portion about said peripheral edge of said face portion such that an expansible chamber is formed between said face portion and said body portion and deformable mounting brackets extending outwardly from said expansible body portion for attachment to the vehicle;
• said expansible body portion including a receptacle for housing said inflator and being formed from injection molded polymeric material of lower rigidity than said face portion and having one or more integrally molded at least partially collapsible pleated profile elements disposed along the sides and across the top of said expansible body portion in raised and lowered profile with respect to said face portion, and one or more deformable ribs disposed across the interior of said expansible body portion such that upon pressurization of said expansible chamber by said inflator, at least a portion of said profile elements undergo collapsible deformation thereby expanding the volume of said chamber and forcing said face portion outwardly to an extended position.