Blanket clamping device

A blanket clamping device for clamping a blanket mounted on a transfer cylinder of an offset rotary printing machine, the transfer cylinder having a periphery and an axis and a clamping duct extending in axial direction of the transfer cylinder, the clamping duct having a bottom with a bore therein and being open at the periphery of the transfer cylinder, the blanket having ends, the blanket clamping device comprising two clamping rails mounted in the clamping duct, each of the clamping rails being connected to one of the ends of the blanket, the clamping rails extending at an angle relative to each other and having surfaces defining a gap therebetween, the gap having a center, at least one screw mounted in the center of the gap and screwed into the bore in the bottom of the clamping duct, the screw having a truncated cone-shaped head, the clamping rails each having a surface facing the truncated cone-shaped head of the at least one screw, each of the surfaces of the clamping rails defining a step, such that the truncated cone-shaped head prevents movement of the clamping rails past the periphery of the transfer cylinder by engaging the steps.