Abstract: A type of service station wiping mechanism for a printing unit, including a fixing seat that is fitted at one end of the printing unit. On said fixing seat is fitted a solenoid and on said solenoid is a spindle. One end of said spindle is joined to a crank, and on the crank is a pushing tapered plane, when the crank moves horizontally in the fixing seat is a wiping pad seat which will move vertically. On said wiping pad seat is fitted a wiping pad. The lower end of the wiping pad seat is resting against the pushing tapered plane on the crank. The solenoid drives the spindle to move the crank and control the wiping pad seat and the wiping pad to move up or down.

Abstract: A feed roller assembly including an axle, a feed roller fixedly mounted around the axle and turned with it to feed a sheet of paper forward, an end cap fixedly mounted on one end of the axle and having a projecting rod raised from an inner side, the projecting rod having a bevel face, and a transmission gear turned about one end of the axle adjacent to the end cap, the transmission gear having a springy projecting rod raised from one end and moved to act against the projecting rod of the end cap, causing the end cap and the axle to be turned with the transmission gear, the springy projecting rod of the transmission gear passing over the bevel face of the projecting rod of the end cap when the roller is pulled by a transmission roller, which delivers the fed sheet of paper forwards, to turn the axle and the end cap at a higher speed than the transmission gear, permitting the end cap and the axle to be turned relative to the transmission gear.