Cam 1 rotates about fixed axis A. Follower 2 oscillates about fixed axis C and carries roller 10 which rolls along the contour of cam 1. Link 3 is connected by turning pairs D and E to follower 2 and to link 4 which turns about fixed axis F. Link 8 is connected by turning pairs K and L to link 4 and to link 9 which turns about fixed axis N. Link 5 is connected by turning pairs M and T to feeler 6 and link 4, and carries roller 7 which rolls and slides along profiled fixed groove b. Feeler 6 is connected by sliding pair P to link 11 which turns about fixed axis B. Motion is transmitted from cam 1 to feeler 6 which slides vertically and also turns about axis B. As the stack of paper is depleted, feeler 6 descends, turning link 9 so that its lug a raises valve d which connects the vacuum cylinder of the paper feeding mechanism by a pipeline to the vacuum pump.
$3288$CmL,FD$