Abstract: A shuttle unit of the type comprising a discoid shuttle body provided with two conical portions, one front and one rear, disposed specularly with respect to the median plane of said shuttle body passing through the race of the shuttle body, and a shuttle driver guided in rotation to make the shuttle body oscillate. The front and rear portions define a containing cavity for the bobbin case and the thread bobbin. The front conical portion forms a base angle with the median plane of the shuttle body comprised between 43° and 49°.