| 摘要 |
<p>In a method of making a head on an elongate blank (26) a blank (26) is moved into a die (16) having a bottom stop (28) such that part of the blank (26) extends outside the die (16) end opposite the bottom stop (28), following which the protruding part of the blank (26) is formed by a pre-upsetter (25) having a pre-upsetting bushing positioned in extension of the die (16) and a punch (27) slidably movable in said pre-upsetting bushing, said pre-upsetter (25) and said die (16) being moved away from each other during part of the forming procedure. The movement of both the punch (27) and the pre-upsetter (25) with respect to the die (16) is positively controlled so that the pre-upsetter (25) and the die (16) are moved away from each other at the end of the forming procedure, while the punch (27) continues to press in a direction toward the die (16). An apparatus for making a head on an elongate blank (26) comprises means for positively controlling the movement of both the punch (27) and the pre-upsetter (25) with respect to the die (16), so that the pre-upsetter (25) is moved away from the die (16) at the end of the forming procedure, while the punch (27) continues to press in a direction toward the die (16).</p> |
