A lightweight interchangeable magnetic sleeve and method of manufacture thereof are disclosed. The sleeve assembly comprises an annular tube in the exterior surface having recesses filled with comparatively rigid magnetic means which are firmly adhered therein. The sleeve assembly includes a tubular radially compressible liner component, relatively slightly shorter than the tube, and bonded inside and substantially axially centrally within the tube thus leaving interior cylindrical end regions of the tube exposed beyond the annular end surfaces of said liner. The remaining exposed interior cylindrical surfaces of the tube are rebated back from the liner exposing annular shoulders within the tube. The rebates are tapped so that correspondingly sized threaded end rings of a more structurally robust, rigid and resilient material than the tube material, can be fitted into the tube ends and tightened against the annular shoulders created by the rebating, placing the entire sleeve assembly under slight compression.

A mandrel for use in a printing apparatus includes a substantially cylindrical mandrel shaft and plastic expansion rings that are slidably and coaxially mounted on the mandrel shaft. The mandrel also includes a locking assembly including a fixed stop ring and a single locking ring that is axially movably mounted on the mandrel shaft. The expansion rings are positioned between the stop ring and the locking ring. In the unlocked position of the locking ring the expansion rings are in a released state in which the axial compression and the radial expansion of the expansion rings are smaller than in a locked position of the locking ring. A printing cylinder sleeve can be fixedly connected to the mandrel by bringing the expansion rings in the radially expanded state. When the printing cylinder sleeve has to be exchanged, this is feasible when the expansion rings are in the released state.

A sleeve station dedicated to the assembly of a sleeve and a mandrel for a flexographic press. The sleeve station can be loaded manually, and assembles the sleeve with the mandrel in a vertical orientation when both are in a vertical orientation with aligned axes, avoiding problems caused by the bending of the sleeves during assembly. After loading of the sleeve, it is returned to a horizontal axis orientation.

A clamping shaft (12) for a rotationally driven part (14) is described. It comprises at least one fluid chamber (28a, 28b) being located inside a shaft body (16) and being delimited by a piston (30a, 30b) and a cylinder part (32a. 32b). Additionally, the fluid chamber (28a, 28b) is delimited by an elastic clamping region (24a, 24b) having a first diameter if the piston (30a, 30b) and the cylinder part (32a, 32b) are in a first relative position, and a second diameter if the piston (30a, 30b) and the cylinder part (32a, 32b) are in a second relative position. Furthermore, a preloading unit (38) is provided, biasing the piston (30a, 30b) and the cylinder part (32a, 32b) towards the second relative position. Moreover, a printing cylinder unit (10) of a printing machine is presented comprising such a clamping shaft (12). Also, a method for operating a clamping shaft (12) is explained.

A method is provided for automatically exchanging a sleeve (18a) of a printing tool (14, 16, 18, 22, 24) mounted in a printing machine (12), in particular a flexographic printing machine, by means of a printing tool handling unit (28) comprising a coupling interface (36). In one step of the method the printing tool handling unit (28) is temporarily coupled to a coupling interface (46) located at the end of a shaft (54, 56, 58, 60) of the printing tool (14, 16, 18, 22, 24) with its coupling interface (36). In a further step, the printing tool handling unit (28) transports the printing tool (14, 16, 18, 22, 24) to a separation unit (78) comprising at least one clamping device (80, 82, 84) and places the printing tool (14, 16, 18, 22, 24) in the clamping device (80) of the separation unit (78). The printing tool (14, 16, 18, 22, 24), in particular a sleeve (18a) of the printing tool (14, 16, 18, 22, 24), is clamped by the clamping device (80), and the printing tool handling unit (28) separates the shaft (54, 56, 58, 60) from the sleeve (18a) by pulling the shaft (54, 56, 58, 60) out of the sleeve (18a) while the sleeve (18a) is clamped in the clamping device (80).

A printing mechanism 1 including a mandrel 2, and a tubular sleeve 3; wherein the mandrel comprises a main body and sleeve support members 6, a plurality of the sleeve-support members being arranged on the main body at intervals in the axial direction; and wherein the sleeve-support member has a plurality of arm portions 7 extending radially so as to support the sleeve from an inside thereof, and moving mechanisms 8 for moving tip vicinities of the arm portions inward/outward in the radial direction; and wherein the sleeve-support member has an interlock mechanism 9 for synchronously driving each moving mechanism of the sleeve support members, the tip vicinities of the arm portions being engaged with the inner surface of the sleeve or released from the engaged inner surface of the sleeve by the synchronous motion of the tip vicinities of all arm portions inward/outward with the interlock mechanism.

A method for assembling a hollow cylinder on, or removing a hollow cylinder from, a further cylinder. The hollow cylinder includes a body with openings for creating an air cushion within a first portion of a shell and a second portion of the shell is gas-impervious or has openings for creating an air cushion of a reduced quantity and/or size compared to the first portion. The openings are connected to a gas feed and a gas inlet inside the body. The further cylinder has openings on a shell and gas is fed though the openings via an internal gas supply. An assembly method includes providing the hollow cylinder, applying a seal to the first portion to prevent escape of gas from the first portion, providing the further cylinder, applying gas to the further cylinder so that gas escapes from the openings, and pushing the hollow cylinder onto the further cylinder.

A dampening fluid useful in offset ink printing applications contains water and a surfactant whose structure can be altered. The alteration in structure aids in reducing accumulation of the surfactant on the surface of an imaging member. The surfactant can be decomposed, switched between cis-trans states, or polymerizable with ink that is subsequently placed on the surface.

A dampening fluid useful in offset ink printing applications contains water and a surfactant whose structure can be altered. The alteration in structure aids in reducing accumulation of the surfactant on the surface of an imaging member. The surfactant can be decomposed, switched between cis-trans states, or polymerizable with ink that is subsequently placed on the surface.

A printing roller comprises a base body which has mounting segments, a printing and a clamping mechanism which has a clamping bushing, which can be displaced in the axial direction, and with respect to the clamping bushing, has a proximal and a distal clamping element which are arranged to detachably clamp the printing sleeve to the base body by means of the radial clamping force in each case, wherein a compression force transmission chain is formed between the clamping bushing and the proximal and the distal clamping elements, by means of which, during an initial clamping phase, the compression force, generated by the clamping bushing is transmitted predominantly or entirely to the distal clamping while the compression force generated by the clamping bushing is applied to the proximal clamping element to a lesser extent than to the distal clamping element or not at all.