While the pressure on a certain part of the machine is within a definite limit, disk 1 with ratchet teeth rotates together with shaft 10 about fixed axis A. Keyed to shaft 10 is main cam 3 which acts on follower roller 6. Main cam 3 carries two auxiliary cams 4 and 5 which are connected to cam 3 by pins a and can slide axially along these pins. Cam 4 carries roller 8 and cam 5, roller 7. Rollers 7 and 8 are held by springs 11 against disk 1 which has two side cams d and b. When the allowable pressure on the part is exceeded, spring 9 is compressed and pawl 2 drops into engagement with a ratchet tooth. This stops disk 1 and cams d and b come into engagement with rollers 7 and 8, forcing cams 4 and 5 along pins a to the left. Now these cams engage the wide follower roller 5, thereby changing the rise, dwell and drop.
$3346$CR,ML$