Abstract: The invention relates to a method and to a device for stabilizing precursor fibers for the production of carbon fibers. In the method, precursor fibers are first heated to a first temperature and held at the temperature for a predefined duration. Subsequently, the precursor fibers are heated to at least one second temperature, which is higher than the first temperature, and held at said temperature for a predefined duration. During each heating and between the heating steps, the precursor fibers are in a gas atmosphere having a negative pressure in the range between 12 mbar and 300 mbar and having an oxygen partial pressure of 2.5 to 63 mbar. The device has at least one evacuable, elongate vacuum chamber for feeding the precursor fibers through, at least two lock units and at least one heating unit.

Abstract: The invention relates to a method and to a device for stabilizing precursor fibers for the production of carbon fibers. In the method, precursor fibers are first heated to a first temperature and held at the temperature for a predefined duration. Subsequently, the precursor fibers are heated to at least one second temperature, which is higher than the first temperature, and held at said temperature for a predefined duration. During each heating and between the heating steps, the precursor fibers are in a gas atmosphere having a negative pressure in the range between 12 mbar and 300 mbar and having an oxygen partial pressure of 2.5 to 63 mbar. The device has at least one evacuable, elongate vacuum chamber for feeding the precursor fibers through, at least two lock units and at least one heating unit.

Abstract: A method for operating a four-roll calendar machine (R), according to which a plastic melt from an extrusion nozzle is homogenized first between a first and second roll (W1, W2), and then between a third and a fourth roll (W3, W4). The position of the third roll (W3) can be modified in relation to the rolls (W1) and/or (W2) even during operation, in order to regulate different operating states.

Abstract: An electric contact coupling for connection of a first group of electric conductors to a second group of electric conductors, and especially for use in the coupling of rail and other vehicles with one another, comprises a first plug contact carrier and a second socket contact carrier which are movable into assembly with one another to bring the plug contact elements of the first contact carrier into electric contact with the socket contact elements of the second contact carrier. The two contact carriers are arranged in respectively associated contact carrier housings. The first contact carrier is movable by a positioning mechanism axially relative to its housing to bring its contacts into engagement with the contacts of the second carrier after the two carrier housings have been brought into engagement with one another. Transversely movable closure members seal the carrier housings against the penetration of dirt and moisture when the carrier housings are uncoupled from one another.

Abstract: An electric contact coupling for connection of a first group of electric conductors to a second group of electric conductors, and especially for use in the coupling of rail and other vehicles with one another, comprises a first plug contact carrier and a second socket contact carrier which are movable into assembly with one another to bring the plug contact elements of the first contact carrier into electric contact with the socket contact elements of the second contact carrier. The two contact carriers are arranged in respectively associated contact carrier housings. The first contact carrier is movable by a positioning mechanism axially relative to its housing to bring its contacts into engagement with the contacts of the second carrier after the two carrier housings have been brought into engagement with one another. Transversely movable closure members seal the carrier housings against the penetration of dirt and moisture when the carrier housings are uncoupled from one another.