Rotating dies for planetary thread-rolling machines - bolt-feeding mechanism synchronised with number of thread starts on die

摘要

In the normal operation of such machines, the bolt-blank feeding mechanism is synchronised with the rotation of the rotating roll-die and there is a precise number (a whole number) of feeding strokes per die-revolution. This practice leads to only a small number of the total thread-starts on the rotating die being used and, when these starts chip or break, the costly die is scrap. The synchronisation should be adjusted in relation to N viz. the number of thread-starts on the periphery of the rotating die, and S viz. the distance between the bolt-blanks where S is a given multiple of the peripheral distance between the thread-starts on the rotating die, and the ratio N/S is not a whole number. By this method the number of thread-starts on the rotating die which are actually used is greatly increased, thus giving much longer die-life.