Patent ID: 9309066
Filing Date: 2016-04-12
CPC Classification: B65H,F16H

Claim Text:
1. A sheet feeding device, comprising: a tray portion on which a sheet is placed; a sheet conveying path extending from the tray portion to convey the sheet in a predetermined conveying direction; a feeding roller driving and rotating to feed the sheet in the conveying direction; a driving portion generating rotation drive force used for driving and rotating the feeding roller; and a drive transmission mechanism transmitting the rotation drive force to the feeding roller, wherein the drive transmission mechanism includes: a rotation axis supporting the feeding roller rotatably; a drive input gear formed in a cylinder like shape having an inner space and arranged on the rotation axis so as to rotate around the rotation axis by input of the rotation drive force of the driving portion; and a drive transmission gear arranged between the feeding roller and drive input gear on the rotation axis so as to rotate around the rotation axis and to become capable of slide-moving in an axial direction of the rotation axis between a first position where the rotation drive force is transmitted to the feeding roller and a second position where the transmission of the rotation drive force to the feeding roller is cut off by transmission of the rotation drive force from the drive input gear, and then, to transmit the rotation drive force to the feeding roller, the drive input gear includes a first engaging portion in the inner space, the drive transmission gear includes a second engaging portion connectable to the first engaging portion, the second engaging portion is inserted into the inner space at the second position, the sheet feeding device further comprises: a ratchet gear mechanism coupling and uncoupling the drive transmission gear to the feeding roller, wherein the ratchet gear mechanism couples the drive transmission gear to the feeding roller in a first rotation direction to feed the sheet by the feeding roller, and uncouples the drive transmission gear to the feeding roller by moving the drive transmission gear to the second position in a second rotation direction opposite to the first rotation direction, the second engaging portion has a slope portion sloped along a rotation direction of the drive transmission gear so as to come close to the side of the drive input gear, and a contacting portion provided in a linked manner with an end at the side of the drive input gear of the slope portion and extended along the axial direction, in the second position, when the drive input gear is rotated, the first engaging portion is moved along the slope portion and the drive transmission gear is pressured to a side of the feeding roller, the drive transmission gear is slide-moved from the second position to the first position, in the first position, when the first engaging portion comes into contact with the contacting portion, the rotation drive force is transmitted from the drive input gear to the drive transmission gear, the sheet feeding device further comprises: a protruded portion arranged at an interval from the first engaging portion in a peripheral direction in rotation of the drive input gear and protruded inwardly in the radial direction from an inner peripheral surface in the drive input gear; and a cylinder portion arranged to penetrate an insertion space formed in the drive transmission gear, inserted into the inner space together with the second engaging portion to come into direct contact with the first engaging portion and protruded portion from the inside in the radial direction and to pivotally support the drive input gear.