PURPOSE: To correctly feed a headed rod by providing a pair of reverse preventing claws in an adsorption pipe guide hole so that the working faces may be opposite to each other, and forming a headed rod guide groove in the opposite surface.

CONSTITUTION: Reverse preventing claws 8, 9 are fitted to an adsorption pipe guide hole 3 of a pipe body by a pin 10 and a spring 11, and a headed rod guide groove 12 is provided in the opposite surface. When the headed rod to be forcibly fed by a hose 7 is fed from a headed rod feeding hole 2 to the pipe body 2, the rod passes through the guide groove 12 provided in the reverse preventing claws 8, 9, and is fed to a holding part 5. Thus, the rod is fed to the holding part 5 in a correct condition without being hit against the wall surface of the adsorption pipe guide hole 3 and reversed thereby.