Patent ID: 6863349

Claim:
A metal frame for chairs with tubular elements, said frame comprising two inverted U-shaped elements, defining two pairs of legs, two L-shaped elements, defining a support for a seat and a back wherein each of the elements is arranged next to one of the preceding elements, two rod cross-members, which are arranged in a lower region so as to join the inverted U-shaped elements and the L-shaped elements, wherein said cross-members are joined to said U-shaped elements and said L-shaped elements by projection welding at a pair of protrusions determined by corresponding recesses in the cross-section, formed by a flattening plastic deformation, said pair of protrusions being formed at outside edges of said recesses, said cross-members being arranged transversely to said U-shaped elements and said L-shaped elements such that said cross-members are arranged also transversely to said recesses and said cross-members rest on said pair of protrusions outside of said recesses, said cross-members being welded to said U-shaped elements and said L-shaped elements at said pair of protrusions upon which said cross-members rest outside of said recesses.