Abstract: An impression roller for gravure printing for use with an electrostatic printing aid, including an axis member or a shaft, joined axially to a steel core, an electrical inner insulating layer extending radially around the core, an electrically semi-conductive outer layer adjoining the outside of the impression layer, and an electrically highly conductive conductor layer arranged between the two. The conductor layer is encapsulated in an electrically insulated exterior. The impression roller is provided with an electric or electronic encapsulated circuit electrically insulated from the outside and having two poles, which is of low resistance in normal operation when the electric current flows from its positive pole to its negative pole and is of high resistance when the flow direction is opposite. The inner pole and outer pole of the circuit are connected to the conductor layer by an inner and outer connection of the impression roller respectively.

Abstract: An impression roller for gravure printing for use with an electrostatic printing aid, including an axis member or a shaft, joined axially to a steel core, an electrical inner insulating layer extending radially around the core, an electrically semi-conductive outer layer adjoining the outside of the impression layer, and an electrically highly conductive conductor layer arranged between the two. The conductor layer is encapsulated in an electrically insulated exterior. The impression roller is provided with an electric or electronic encapsulated circuit electrically insulated from the outside and having two poles, which is of low resistance in normal operation when the electric current flows from its positive pole to its negative pole and is of high resistance when the flow direction is opposite. The inner pole and outer pole of the circuit are connected to the conductor layer by an inner and outer connection of the impression roller respectively.

Abstract: An apparatus for fixing a sheet on the surface of an electrically conductive cylinder of a printing machine for processing sheets, in particular, a sheet-fed offset printing machine. The apparatus includes an electrode that extends over the width of the cylinder for creating an electric field for adhering the sheet to the surface of the cylinder and an air directing device for directing pressurized air streams against the sheet and preliminary positioning the sheet onto the cylinder prior to being acted upon by the electric field. Various alternative embodiments of the sheet fixing apparatus are disclosed.

Abstract: An apparatus for fixing a sheet on the surface of an electrically conductive cylinder of a printing machine for processing sheets, in particular, a sheet-fed offset printing machine. The apparatus includes an electrode that extends over the width of the cylinder for creating an electric field for adhering the sheet to the surface of the cylinder and an air directing device for directing pressurized air streams against the sheet and preliminarily positioning the sheet onto the cylinder prior to being acted upon by the electric field. Various alternative embodiments of the sheet fixing apparatus are disclosed.

Abstract: Solar radiation is concentrated onto an absorber which includes a concentrator element. The concentrator element concentrates incident solar radiation in a focal spot on the absorber to obtain a measurable variable which reliably characterizes the alignment of the concentrator element on the sun. The variable is independent of variations in the apparent position of the sun, weather influences, thermal expansion, and play in the suspension of the concentrator element. The device measures the flux density of the solar radiation in the region of the focal spot using an inlet opening, through which part of the solar radiation passes, a diffuser for reducing the flux density of the solar radiation, and a detector for measuring the flux density which is reduced by the diffuser.

Abstract: A color printing arrangement has a series of printing stations in each of which a different color is imprinted upon predetermined regions of a travelling band to form color images. A device for measuring the width of the band by sensing the edges thereof is located immediately upstream of each printing station. The width of the band at the first printing station is compared with the width at each of the following printing stations. As long as the widths at the latter printing stations are the same as that at the first printing station, the band is allowed to continue travelling unchanged. However, when the width of the band at a printing station downstream of the first printing station differs from the width at the first printing station, the band is operated upon to return the width to its original value. The reason is that a departure from the original width of the band causes the predetermined regions which are to be imprinted to be moved out of alignment with the printing devices in the printing stations.