| 摘要 |
The apparatus of the invention is characterized by comprising a die through which the end of the tube is passed in order to form the point, and which is provided with a first substantially cylindrical bore of diameter less than the diameter of said tube, a substantially conical second bore coaxial with the preceding and of which the minimum diameter is equal to the diameter of said first bore and the maximum diameter is greater than the diameter of the tube, and at least three revolving bodies disposed in corresponding seats of said die, each of which projects radially to a predetermined extent from the surface of said second bore towards the axis of the bore itself, and drive means arranged to axially move said die relative to said tube in order to bring the end of the tube inside said first and second bore and into cooperation with said revolving bodies. |
