The flanged edge (5.3) is sequentially connected to a rear longitudinal beam (4) and a connection plate (6) between a rear floor board and a front transversal beam.

The housing (1a) has at least one transverse bridge which divides it lengthwise into at least two chambers (7.1a; 7.1b; 7.2a; 7.2b).

A crossbar (11, 12) is attached to the cartridge-shaped contact piece carriers (5, 6) on the shell side.

The crossbar could be substantially straight with a cylindrical cross section.

One or more of the rods include an aperture (115) defining an opening through a cross-section of the rod.

A second traverse center line (64) extends through the center line of the second and fourth cylindrical members.

A first transverse center line (62) extends through the center lines of the first and third cylindrical members.

One anterior transverse arch that runs across the middle of the foot.

A length compensating device is arranged at at least one of both ends of the cross member (6) and enables the overall length of the cross member (6) to be altered between both of its ends.

The flanged edge (5.3) is sequentially connected to a rear longitudinal beam (4) and a connection plate (6) between a rear floor board and a front transversal beam.

Said crossmember (1) is composed of a base body (2) and a reinforcement (3) and has at least one wall (22) running transversally to the crossmember (1).

In cross section, the hollow beam tapers toward the top rail of the sidewall and terminates within an area of the capping beam.

The frame (20) is fixed beneath the crossmember (18) and consists of a lower transverse beam (50) and two side struts (52) connecting the lower beam (50) to the crossmember (18).

A preferred cross-section, is an elliptical cross-section.

Each stage pole has a tube-like shape having any one of a polygonal cross-section, an oval cross-section, and a semicircular cross-section.