Printing machine blanket cylinder cleaning device

Claim 1

A printing machine having a blanket cylinder rotatable about a longitudinal axis, and an improved cleaning device for said blanket cylinder, said device comprising a cleaning roller having an axis of rotation and an outer surface, different parts of said outer surface being at different radial distances from said axis of rotation, the roller being mounted adjacent said cylinder with the said roller axis fixed and parallel to the said cylinder axis at a distance therefrom substantially equal to the maximum radial distance of the roller outer surface from its axis of rotation, whereby, as the roller makes one revolution about its axis the surface of the roller contacts the blanket cylinder for part of the time only, and further comprising first and second ratchet wheels, and first and second pivotal pawls respectively associated with said ratchet wheels, said ratchet wheels being rotatable with said cleaning roller, ratchet teeth disposed on a part of the circumference of said first ratchet wheel such that there is a circumferential arc wherein no ratchet teeth are provided, drive means for continuously oscillating said first pawl through an arc not greater than said circumferential arc, said second pawl being intermittently oscillatable.