Abstract: The invention is related to a supporting structure, especially for attachment to a robot arm and for securing tools, such as clamping, gripping and suction devices or other equipment such as valves, sensors and the like. The supporting structure is formed of not less than two shaped bars and of at least one clamping member. The clamping member conforms to the profile of the bars and is formed of at least two parts, and the shaped bars are provided with at last one undercut groove, with an adjusting strip being arranged within the said groove and being displaceable and firmly clamped therein. Provided both within the clamping member and within the adjusting strip, for insertion of an adjusting pin, are adjusting ports adapted to be placed in registry by a relative displacement of the adjusting strip and the clamping member, with the said adjusting ports being of identical diameters.