Patent ID: 7942473

Claim:
A motor vehicle underframe comprising: two side members that are oriented approximately in a longitudinal direction of the vehicle, are spaced apart from each other, and each having a first end; a central crossmember that is fixed to each of the first ends of the side members, in a transverse direction of the vehicle, and that includes a lower face turned toward the underside of the vehicle, and an upper face facing an opposite way to the lower face; a first floor element fixed to the side members and to the lower face of the central crossmember; on each side of the underframe, a lateral reinforcing element that is fixed to the end of an central crossmember and that extends longitudinally and in a plane approximately perpendicular to the first floor element; and a second floor element fixed to the upper face of the central crossmember, wherein the first end of each of the side members is continued by a sub-crossmember portion fixed to the lower face of the central crossmember, wherein the sub-crossmember portion is attached to a fixing portion comprising a forward portion welded to a lateral face of the central crossmember that is toward the second floor element and an upper portion fixed to the underside of the second floor element, wherein the fixing portion converges gradually on a respective lateral reinforcing element, and wherein the fixing portion is fixed to a longitudinal portion of respective lateral reinforcing element, such that forces acting on each of the members side are transmitted to respective lateral reinforcing elements.