A roll feed apparatus for intermittently and unidirectionally feeding a sheet material has a first roll fixedly carried by a first roll shaft on a first axis, and a second roll carried by a second roll shaft on a second axis. The rolls cooperate in clamping and feeding sheet material therebetween. A turning shaft, rotatable by an operation lever, includes a first shaft portion on a third axis and second shaft portions on a fourth axis on both axial ends of the first shaft portion, rotatably supported by a housing through self-centering bearings. A pivotable member rotatably supports portions of the first roll shaft on both sides of the first roll. The pivotable member pivotally supported by the first shaft portion of the turning shaft moves the first roll towards and away from the second roll. The third axis extends in parallel with the first axis and is laterally spaced from the first roll. The fourth axis crosses the third axis at a predetermined small angle. The crossing point of third and fourth axes is positioned on or in the vicinity of a straight line which passes an axial mid-portion of the first roll and extends perpendicular to the first axis.

A training idler for guiding a travelling conveyor belt so that the belt follows a central path. The training idler includes an axle adapted to be mounted to a conveyor support frame, a steering roller rotatably mounted on the axle and adapted to be aligned generally transverse to a conveyor belt which will ride thereon, and a pivot connecting the roller to the axle, the pivot defining a generally perpendicular pivot axis about which the steering roller is able to pivot. The steering roller has an outer peripheral surface of generally right circular cylindrical form and has a central region and opposite edge regions, the edge regions having a peripheral circumference which is either greater than or less than the peripheral circumference of the central region. The arrangement is such that, in use, as a conveyor belt riding on the steering roller moves towards one or other edge region, the difference in the peripheral speeds of the central region and that edge region will cause the steering roller to pivot on the pivot axis and steer the belt back to its central path.

A combined fabric stretching and straightening apparatus is comprised of a pair of cylinders having helical configurations on their periphery the cylinders being mounted for rotation on a shaft adapted to be driven in a direction opposite the direction of feed of a fabric web. The cylinders may rotate relative to each other and the shaft or may be coupled to rotate with the shaft by clutches interposed between the cylinders and shaft. Sensors are optionally provided for energizing one or the other clutch so as to center the fabric as it is fed.

The present invention is directed to preventing image damage caused by pressure applied to print media during a folding process, by using pressure and abrasion resistant inks only on those sections of print media that are subjected to pressures that would otherwise damage the images printed on those sections. Images on other sections of the print media are printed using less expensive or general purpose inks.

A web guide roller assembly for a printing machine utilizes a cylindrical roller support body and a concentric hollow roller body. An annular space between the support body and the roller body is filled with a pressure medium so that the roller body floats on the support body. Suitable end seals are utilized to prevent escape of the pressure medium.