Shaft 1 is turned by a device (not shown) connected to a float whose position depends upon the water level in a reservoir or tank. Shaft 7 turns disk 2 which has curvilinear cam surface a and depresses roller b at the end of pawl 3. This turns pawl 3 so that its tip is withdrawn from recess c. At this, sleeve 4 and wheel 5 are turned by spring 7 together with cam disk 6, rigidly mounted on sleeve 4, so that a lobe of disk 6 closes electric contact 8.
$3281$CmL,FD$