Shaft 9 oscillates about fixed axis A about 180° in each direction. Plate cam 1, keyed to shaft 9, has flat lobe a and a slot in which cam 4 turns about axis B. When shaft 9 turns counterclockwise, roll 2 of follower 3 is gradually depressed by cam 4, slowly releasing the clamping device to which the follower is connected. When roll 2 reaches contact with lobe a, it runs against adjusting screw 10 of latch 5 and turns the latter about axis D, bending flat spring 7. This releases cam 4 which is turned by springs 6 clockwise about axis B to its lower position. At this point, shaft 9 reverses and, in clockwise rotation of the cam assembly, roll 2 reaches the end of lobe a and is returned suddenly by spring 8 into contact with the concentric portion of cam 1, so that follower 3 quickly engages the clamping device. As cam 1 continues to turn clockwise, roll 2 contacts the protruding end of cam 4, turning it counterclockwise about axis B by overcoming the resistance of springs 6 until it is returned to its initial position in which it is held by latch 5 and spring 7.
$3269$CmL,SE$