High rotational speed autoreversing axially oscillating ink roller

摘要

A cylindrical ink roller sleeve is mounted on a fixed shaft for sliding axially on and rotating on the fixed shaft. Left and right hand twist helical grooves or internal threads are formed in a driver cylinder concentric with the inside of the roller sleeve. A control shaft is mounted on said fixed shaft for sliding axially in opposite directions to right and left limits. Prongs on opposite ends of the control shaft are displaced 90 DEG about its axis so prongs at one end engage a helical groove of one twist while the prongs on the other end are turned out of engagement with the helical groove of opposite twist. Engagement will cause the roller to drive in one axial direction or the other until strikers disengage one and engage the other at the limit of axial travel. Then one or two idle revolutions occur and the roller dwells in its axial movement until the control shaft shifts to a limit stop in which case the roller beings to shift in the opposite direction. The idle revolutions eliminate the stress that would occur if reversal occurred instantaneously.