Abstract: The present invention provides a sheet feeding apparatus for separating and feeding sheets contained in sheet containing means one by one that has separating and feeding means including a feeding rotary member and a separating rotary member brought into pressure contact with the feeding rotary member and a torque limiter provided between the separating rotary member and a driving shaft wherein a coefficient of friction of the separating rotary member is set so that relations that &mgr;BC N>T/r, &mgr;BP>&mgr;CP, and T/r>&mgr;CP N>&mgr;PP N may be established among a coefficient of friction &mgr;BC between the feeding rotary member and the separating rotary member, a coefficient of friction &mgr;BP between the feeding rotary member and the sheet, a coefficient of friction &mgr;CP between the separating rotary member and the sheet, a coefficient of friction &mgr;PP between the sheets, a pressure contact force N of the separating rotary member, an idling torque T of the torque limiter and an effective

Abstract: A device of aligning or arranging a paper in a printer comprising a transport part including feed roller and pinch roller, and which transports or counter-transport a paper between the rollers; a pickup roller which supplies a sheet of papers of paper load cassette to the roller; a paper feed plate providing the pressure for the frictional power to pick up a paper; and one-way clutch for preserving frictional power between a pickup roller and a paper when the feed roller which drives the pickup roller rotates in a counter direction.

Abstract: A sheet feeding apparatus including a movable sheet supporting device for supporting a sheet, a sheet feeding device urged against the sheet supported by the sheet supporting device and adapted to rotate in a sheet feeding direction to feed the sheet, a feeding device disposed at a downstream side of the sheet feeding device in the sheet feeding direction and adapted to feed the sheet fed from the sheet feeding device, a separating roller adapted to rotate in a sheet restoring direction to restore the sheet fed from the sheet feeding device, a drive transmitting device for stopping rotation of the sheet feeding device toward the sheet feeding direction before a leading end of the sheet fed out from the sheet supporting device by the sheet feeding device reaches the feeding device and then for rotating the sheet feeding device in the sheet feeding direction again, and a pressing and retracting device for moving the sheet supporting device which abutted the sheet against the sheet feeding device before the lead

Abstract: In a paper transport device, a first roller serving as a separation roller is situated underneath a second roller serving as a document feed roller, together forming a roller pair. A rotary shaft of the separation roller is biased upward toward the document feed roller by means of an elastic element. One end of the rotary shaft is connected to a drive shaft via a coupler while a connecting bar is joined to the other end of the rotary shaft obliquely from above. An extreme end of the connecting bar opposite to the rotary shaft is attached to a support plate fixed to a main body of the paper transport device in such a way that the connecting bar can swing about pivot pin fixed to the support plate. In the paper transport device thus constructed, one end of the rotary shaft fitted to the coupler acts as a point of support, allowing the other end of the rotary shaft to move downward overwhelming an upward-lifting force of the elastic element when forced downward by the connecting bar.

Abstract: A drive power transmission mechanism situated between a drive motor and a pick-up roller for transmitting a drive power to the pick-up roller from the drive motor to rotate the pick-up roller under a normal condition. The rotating pick-up roller picks up a sheet at a time from a stack of sheets piled up on a paper feed tray. The transmission mechanism includes a torque limiter that interrupts drive power transmission to the pick-up roller from the drive motor when the pick-up roller contacts an empty paper tray. The drive power transmission mechanism also includes a clutch for preventing drive power transmission from the pick-up roller to the drive motor. The drive power transmission from the pick-up roller to the drive motor occurs, for example, when both the pick-up roller and a feed roller contact the same sheet and the pick-up roller rotates faster than a predetermined speed.