Door reinforcement for motor vehicles

A door reinforcement for protecting a car against sideways collision comprising:

• an upper and a lower rigid horizontal support parallel to one another, said upper rigid horizontal support having a recess therein and forming an outer sealing edge along an outward side of a window;
• an inner horizontal support positioned along an inner side of said window forming an inner sealing edge thereof;
• and
• at least one flexible pretensioned bracing band having first and second ends, said first and second ends attached to said upper and lower rigid horizontal supports, respectively, said first end penetrating into said recess and having adjacent thereto a wedge, said wedge becoming tighter when subjected to a tensile load on said bracing band.