A rotary impulse device for an air motor or electric motor drive designed
to produce an adjustable output torque is provided. The driven output
shaft or impulse member has a cam surface driven by a driver which is
axially or radially movable in a driving cage mechanism whereby the torque
developed by the impulse device cyclically varies between zero and a
predetermined adjustable maximum quantity. Due to the cyclical variation
in the torque developed there is no impact component of the torque
delivered and therefore the tightening torque will not increase as the
number of torque cycles increases.
