Abstract: An apparatus designed to efficiently and positively clean a main piping not only totally, but also partially by the reciprocation of a pig. The cleaning apparatus is provided with a launcher (4) for projecting a pig (1) and a catcher (36) for receiving the pig (1) at both ends of a main piping (37). A compressed gas is supplied from a feed nozzle of the launcher to thereby send the pig to the catcher (36). In consequence to the arrival of the pig, the compressed gas is discharged through a discharge nozzle (29) of the catcher (36), when the pressure is decreased and the pig is accordingly stopped. The decrease of the pressure is detected by a pressure sensor (33) of the launcher (4). When the pig arrives at the catcher (36), it is detected by a pressure sensor (33) of the catcher (36). The compressed gas is supplied from a feed nozzle (22) of the catcher (36) based on the detecting signal of the pressure sensor (33 ) of the launcher (4), to thereby send the pig towards the launcher (4).

Abstract: A paper feed mechanism for feeding fan-fold paper into a printer, a typewriter, or the like has a drive roller, an idler roller, and a pin belt trained around the drive and idler rollers and having a series of pins for engaging in perforations of the fan-fold paper. The fan-fold paper is guided by first and second paper holders that are angularly supported on a frame. The first paper roller is of an arcuate shape and extending along an outer periphery of the drive roller. The first paper roller is angularly movably supported on the second paper roller. The second paper roller extends along a straight portion of the pin belt between the drive and idler rollers.