Abstract: A device for actively steering and tensioning a web as it moves along a predetermined path is described. The web is partially wrapped around a rotatable guide roller. A first end of the guide roller is carried on a tiltable support member. The opposite end is attached to a pivotal bearing. A non-contact sensor is positioned to detect lateral misalignment of the web. A control device responsive to the sensor controls the tilting of the support member thereby to correct for lateral misalignment of the web. Pressure devices exert a predetermined pressure on each end of the guide roller independently of the position of the tiltable support member, to push the guide roller towards the web to generate the desired tension.

Abstract: In a reverse clutch, which is switchable by means of couplings, the input shaft and the output shaft lie in line with each other. A compact reverse clutch which is easy to assemble can be obtained by making use of face gears which are mounted on the input and output shaft. The cylindrical pinions placed between the face gears and in mesh therewith are mounted in an intermediate ring. A coupling can connect the intermediate ring to the housing. Another coupling can connect the input and the output shaft to each other directly or indirectly by way of the toothing.

Abstract: An electrostatographic printer includes an imaging station for forming a latent electrostatic image on the surface of a drum, a toner development station for developing the latent image to form a toner image, and a toner transfer station for transferring the toner image onto a moving web. An image-fixing station for fixing the toner image on the web includes two pairs of radiant heat sources, the peak energy output wavelength of which lies in the non-visible part of the spectrum. The radiant sources may be located in hingedly mounted pairs of housings in such a manner that the housings may be moved into a closed position to shield the radiant sources from the web when the speed of movement of the web falls below a predetermined value. Thus, damage to the web when movement of the web stops is avoided.