Abstract: An image-forming machine which has an image-forming unit that moves substantially horizontally between an acting position in a housing and a non-acting position that is drawn out forward. The image-forming unit has a frame having a front wall member and a rear wall member, and a plurality of image-forming devices mounted on the frame. The front wall has a pair of receiving holes arranged at a distance in the transverse direction and the rear wall has a pair of pins located at a distance in the transverse direction. In a preferred embodiment, the housing has a pair of pins located in the front and a pair of receiving holds in the rear such that when the image-forming unit is brought to the acting position, the receiving holes of the front wall engage the front pins of the housing and the pins on the rear wall engage the receiving holes in the rear of the housing.

Abstract: An image-forming machine includes an image-forming unit, a transfer belt assembly disposed beneath the image-forming unit so as to freely ascend and descend between an acting position and a non-acting position, and a lift device for asending and descending the transfer belt assembly. The transfer belt assembly includes a driven roller, a tension roller, an endless belt wrapped around the driven roller and the tension roller, and a resilient urging device for resiliently urging the tension roller toward a direction of applying tension to apply tension to the endless belt. A tension release device is disposed which, when the transfer belt assembly is descended to the non-acting position, moves the tension roller in the direction in which tension is no longer applied, against a resilient urging action of the resiliently urging device, so that the application of tension to the endless belt is discontinued.

Abstract: An image-forming machine which forms an image on a photosensitive material drum which passes through the steps of electric charging, exposure to light, developing and transfer. A pair of side walls are disposed opposite to each other, spaced at a distance. Inner wheels of bearings have an inner wheel and an outer wheel. The inner wheels are secured to the outer peripheral surfaces of the photosensitive material drum at both ends thereof, and outer wheels of the bearings are secured to the corresponding side walls, so that the photosensitive material drum is rotatably supported by the side walls.

Abstract: This is invention is directed to a shaft coupling for coupling a first shaft and a second shaft. The shaft coupling includes an outer ring for encasing one end of the first shaft and one end of the second shaft; a first pin provided in the outer ring and the first pin extending in a first direction; and a second pin provided in the outer ring and the second pin extending in a second direction substantially orthogonal to the first direction; wherein the first shaft and the first pin are so set such that the end of the first shaft is movable along the first pin and the second shaft and the second pin are so set that the end of the second shaft is displaceable along the second pin.