Abstract: A pulley comprises a hollow-cylinder support element rotatably supporting a hollow body about a rotational axis and having first and second dome-shaped axial ends. An attachment element has a central axis extending in an axial direction and a complementary dome-shaped axial end abutting the first dome-shaped axial end of the support element. A rod extends within the support element and has a first axial end fixedly connectable with the complementary dome-shaped axial end of the attachment element. A fixing element is connected with a second axial end of the rod and has a complementary dome-shaped axial end abutting the second dome-shaped axial end of the support element. The rotational axis of the hollow body is angularly pivotable relative to the central axis at the fixing element. One of the first and second dome-shaped axial ends of the support element is concave and the other is convex.

Abstract: A printing machine which has a plurality of printing units each including several rollers is equipped with a gear train which drives at least one roller of each of the printing units. At least associated two of the gear wheels of the gear train are coaxially mounted on a common shaft, one of them being movable toward and out of contact with the other gear wheel for establishing entraining connection therewith and for permitting angular displacement of the associated gear wheels relative to one another, respectively. The angular position of the associates gear wheels is to be changed when the mode of operation of the printing machine is to be changed from first page printing mode to first and second page printing mode. The arrangement which connects and disconnects the associated wheels includes a plurality of moving units which simultaneously act on the other gear wheel and which are mounted on an annular clamping element mounted on the other side of the one gear wheel from the one gear wheel.

Abstract: A rotary printing machine has at least two successive printing stations. A self-contained aggregate is located between these printing stations and can be inserted and removed from between them as a unit. The aggregate has a transfer roller which receives sheets from one of the printing stations, one or more heaters for heating the sheets on the transfer roller, and a reversing roller which receives sheets from the transfer roller, selectively reverses them and furnishes them to the other of the printing stations.

Abstract: A printing machine receives single sheets which are removed from a stack by the suction cups of a feeding mechanism which is combined with a monitoring unit serving to detect the absence of sheets at the undersides of suction cups or the lifting of two or more sheets. The monitoring unit employs a transducer having two feelers which determine the thickness of lifted sheet material and an indicating device which is actuated by the feelers and produces signals serving to indicate the absence of sheets, the lifting of two or more sheets and/or to control the operation of the printing machine. The suction cups can form part of the transducer when the latter is designed to detect only the absence of sheets or they form part of a second transducer which is provided in addition to the first mentioned transducer.

Abstract: A printing machine receives single sheets which are removed from a stack by the suction cups of a feeding mechanism which is combined with a monitoring unit serving to detect the absence of sheets at the undersides of suction cups or the lifting of two or more sheets. The monitoring unit employs a transducer having two feelers which determine the thickness of lifted sheet material and an indicating device which is actuated by the feelers and produces signals serving to indicate the absence of sheets, the lifting of two or more sheets and/or to control the operation of the printing machine. The suction cups can form part of the transducer when the latter is designed to detect only the absence of sheets or they form part of a second transducer which is provided in addition to the first mentioned transducer.