Sheet conveying apparatus and image forming apparatus

Abstract

A sheet conveying apparatus includes a first roller, a second roller, a bush member, an urging member, and a conveyance guide member. The urging member urges the bush member in such a direction that the second roller approaches the first roller. The conveyance guide member is fitted to the rotation shaft of the second roller to be movable between a guiding position in which the conveyance guide member guides the sheet, and a retracted position in which the conveyance guide member is retracted from the guiding position, and it contacts, in the retracted position, a body frame to move the bush member against the urging force of the urging member in such a direction that the second roller separates from the first roller.

What is claimed is: 
     
         1 . A sheet conveying apparatus comprising:
 a first roller that is rotatably supported on a body frame of an apparatus body;   a second roller that is disposed so as to face the first roller to constitute a pair of conveying rollers;   a bush member that is supported on the body frame so as to be movable along a radial direction of the first roller, the bush member rotatably supporting the second roller;   an urging member that urges the bush member in such a direction that the second roller approaches the first roller; and   a conveyance guide member that guides a sheet that is conveyed to a nip portion in the pair of the conveying rollers,   wherein   the conveyance guide member is fitted to a rotation shaft of the second roller, the conveyance guide member being movable between a guiding position in which the conveyance guide member guides the sheet, and a retracted position in which the conveyance guide member is retracted from the guiding position, the conveyance guide member contacting, in the retracted position, the body frame so as to move the bush member against an urging force of the urging member in such a direction that the second roller separates from the first roller.   
     
     
         2 . The sheet conveying apparatus according to  claim 1 , wherein
 the conveyance guide member has a pair of bearing portions that are rotatably fitted one to each end of the rotation shaft of the second roller,   the bearing portions are shaped as an eccentric cam having in an outer circumferential part thereof a small diameter portion and a large diameter portion, and   in the guiding position, the small diameter portion comes close to the body frame to make the second roller contact the first roller under the urging force of the urging member, and in the retracted position, the large diameter portion contacts the body frame to make the second roller separate from the first roller against the urging force of the urging member.   
     
     
         3 . The sheet conveying apparatus according to  claim 1  further comprising:
 an openable/closable portion that is fitted opposite the first roller across the second roller, the openable/closable portion being openable and closable relative to the apparatus body, 
 wherein 
 the openable/closable portion has a positioning portion that, with the openable/closable portion closed, contacts the conveyance guide member arranged in the guiding position and positions the conveyance guide member. 
 
     
     
         4 . The sheet conveying apparatus according to  claim 1 , wherein
 lifting up the sheet nipped in the nip portion in the pair of the conveying rollers lets the conveyance guide member move from the guiding position to the retracted position so that the second roller separates from the first roller.   
     
     
         5 . An image forming apparatus comprising the sheet conveying apparatus according to  claim 1 .