Abstract: The invention relates to a sound-absorbing roof construction of a hall (01) with walls (02), several roof trusses (03) resting at least at their ends on the walls (02) and with a sound-reflecting roof cladding (06) carried by the roof trusses (03). On the side faces of several of the roof trusses (03) there are absorber strips (04) which are composed of sound absorber elements. A sound-reflecting section of the roof cladding (06) extends between adjacent roof trusses (03) with the absorber strips (04) with a width that is at least twice the average height of the roof trusses (03). The invention also relates to a sound absorber arrangement with sound absorber elements which are arranged in a hall (01) with walls (02) and a roof structure which closes the hall upwards, the roof structure comprising a plurality of roof trusses (03) and a roof cladding (06) carried by them.

Abstract: A cylinder drive for a rotary printing press uses bearing rings that are in contact with each other. A friction torque that is produced during the printing process, as a material passes between the cylinder which carry the bearing rings, is approximately compensated by an additional friction torque caused by the cooperating bearing rings.