Cam 1 is keyed to shaft 7 and rotates about fixed axis A. Cam 2 is keyed to shaft 8 and is rotated about fixed axis B through sleeve 3. Sleeve 3 is connected to shaft 7 by dog-point setscrews 4 whose tips slide along helical slots a in shaft 7 and to shaft 8 by pin 5 which passes through an axial slot in this shaft. Pin 5 extends through a hole in shifter shaft 9 which can slide axially inside hollow shaft 8. To change the relative angular position of cams 1 and 2, lever 6 is turned clockwise, pulling shifter shaft 9, pin 5, sleeve 3 and setscrews 4 to the left with respect to shafts 7 and 8. The tips of setscrews 4, operating in helical slots a, turn sleeve 3, shafts 8 and 9, and cam 2 through a certain angle with respect to cam 1. The angle through which cam 2 is turned with respect to cam 1 depends upon the displacement of shaft 9 which, in turn, depends upon the angle of rotation of lever 6.
$3077$SmC,ML$