Abstract: A toner image fixing device includes a heat roller, and a backup roller engaged with the heat roller to form a nip therebetween. A paper carrying a toner image is passed through the nip whereby the toner image is thermally fused and fixed on the paper. The heat roller, which is stained by a part of the fused toner during the fixing process, should be cleaned before a toner image is fixed on a successive paper without staining. To this end, a cleaning roller made of a felt material is pressed against the heat roller so as to be rotated together with the heat roller by a frictional force acting therebetween. The cleaning roller must be periodically replaced. The fixing device is constituted such that the replacement of the cleaning roller can be easily and quickly carried out.

Abstract: Disclosed is a system for automatically successively inserting a plurality of U-shaped heat transfer tubes into holes of support members of an equipment such as a heat exchanger. The system has fixing means for removably fixing the support members such that the corresponding holes of the support members are axially aligned; gripping means adapted to pick up one of the heat transfer tubes and movable to bring the heat transfer tube toward the holes of supporting members; a positioning means disposed between the gripping means and the fixing means and adapted to hold the gripped heat transfer tube horizontally and to make the same align with the holes in the support members; and control means operatively connected to the gripping means and the positioning means so as to sequentially control the operation of both means in a predetermined sequence. The system operates as follows under the control of the control means. The gripping means grips the heat transfer tube and raises the same.