CYLINDRICAL GRINDING MACHINE

A cylindrical grinding machine comprising a work spindle, reversible motor means for rotatively driving the work spindle in a first rotational direction during a machining operation and in a second opposite rotational direction, means for stopping the work spindle, rotating in the second direction, at a predetermined angular position including key means secured to the work spindle at a predetermined angular position, bracket means mounted for pivotal displacement from a raised position to a lowered position, means for maintaining the bracket means at the raised position, stop means mounted on the bracket means for pivotal displacement from a retracted positon to an advanced key blocking position, means for displacing the stop means from the retracted to the advanced position whereby rotation of the spindle in the second opposite direction will engage the key with the stop means rotatively displacing the bracket from the raised to the lowered position and means for maintaining the spindle means at the selected angular position including latch means mounted for pivotal displacement from a retracted position to an advanced position for locking the key between the latch means and the stop-means, and means for pivotally displacing the latch means from the retracted position to the advanced position when the bracket has been pivotally displaced from its raised to its lowered position.