(under subclass 504) Devices in which each of the coupling members consists of a rigid and integral part which is interfitted with the complementary coupling member, the members being maintained in coupled relationship by the shape of the parts and draft and gravity forces acting thereon.
(1) Note. The coupling elements may be movably connected to the respective vehicles and need to be rigid only in that portion which directly cooperates with the complementary coupling element to effect the connection between the vehicles.
