Car door sill construction - has section of reduced height towards front area of front opening with triangular gussets towards rear of opening

The purpose of the design is to improve the boarding and alighting comfort for the user by reducing the height of the sill without sacrificing the stiffness characteristics of the body in the critical areas of the door openings. This is achieved by reducing the sill height in the door opening areas (12) and (13) respectively instead of the height indicated by (11). The loss of cross sectional area is made up by a rising contour towards the rear of the body resulting in additional cross section areas indicated by triangle shapes (9, 10). These areas, being near the seats are not detrimental to the usable door opening areas.