Cam 1 rotates about fixed axis A and has twelve lobes a. Follower 3 oscillates about fixed axis B and carries rollers 4 and 5 which are located so that when roller 5 is on a lobe a of cam 1, roller 4 is in a recess between adjacent lobes, and vice versa. Flexibly attached to follower 3 is saw blade 2 which is reciprocated vertically to obtain the sawing motion. In one revolution of cam 1, saw blade 2 has twelve upstrokes and twelve downstrokes.
$3169$SmC,FD$