Sheet conveying device and image forming apparatus incorporating the sheet conveying device

Abstract

A sheet conveying device includes a drive roller, a driven roller, a guide, and a pressure mechanism. The drive roller rotates to convey a sheet in a sheet conveyance path. The driven roller is driven by the drive roller to rotate and convey the sheet in the sheet conveyance path with the drive roller. The guide has a center of rotation coaxially disposed with a center of rotation of the driven roller. The guide is rotated between a guide position and an open position, guides the sheet conveyed in the sheet conveyance path at the guide position, and opens open the sheet conveyance path at the open position. The pressure mechanism is disposed on the guide to press the driven roller to the drive roller in a pressure direction at a given contact pressure. The driven roller moves relative to the drive roller in an orthogonal direction to the pressure direction in conjunction with the guide rotating.

What is claimed is: 
     
         1 . A sheet conveying device comprising:
 a drive roller to rotate and convey a sheet in a sheet conveyance path;   a driven roller driven by the drive roller to rotate and convey the sheet in the sheet conveyance path with the drive roller;   a guide having a center of rotation coaxially disposed with a center of rotation of the driven roller, the guide to:
 rotate between a guide position and an open position; 
 guide the sheet conveyed in the sheet conveyance path at the guide position; and 
 open the sheet conveyance path at the open position; and 
   a pressure mechanism disposed on the guide to press the driven roller to the drive roller in a pressure direction at a given contact pressure,   wherein the driven roller moves relative to the drive roller in an orthogonal direction to the pressure direction in conjunction with the guide rotating.   
     
     
         2 . The sheet conveying device according to  claim 1 , further comprising:
 a support rotatably supporting the guide,   wherein the pressure mechanism includes a pressing portion to:   press the driven roller to the drive roller; and   position the driven roller in the orthogonal direction, and   the guide is slidable to the support in a given range in the orthogonal direction.   
     
     
         3 . The sheet conveying device according to  claim 2 ,
 wherein the guide has a support slot supported by the support, and   the support slot extends in the orthogonal direction.   
     
     
         4 . The sheet conveying device according to  claim 2 , further comprising a positioner to stationarily position the guide at the guide position. 
     
     
         5 . The sheet conveying device according to  claim 2 , further comprising a slider to slide the guide relative to the support when the guide is rotated. 
     
     
         6 . The sheet conveying device according to  claim 5 , further comprising:
 a housing framework; and   a cam-contact portion attached to the housing framework,   wherein the slider includes a cam mounted on the guide to contact the cam-contact portion,   the cam is separated from the cam-contact portion when the guide is at the guide position, and   the cam contacts the cam-contact portion to cause the guide to slide on the support when the guide is rotated.   
     
     
         7 . The sheet conveying device according to  claim 1 ,
 wherein the pressure mechanism includes:   a holder rotatably supported by the guide and including a pressing portion to:
 position the driven roller in the orthogonal direction; and 
 press the driven roller; and 
   a biasing force applier to bias the holder in a sheet conveyance direction that is the orthogonal direction.   
     
     
         8 . The sheet conveying device according to  claim 7 , further comprising a restrictor to restrict a rotation of the holder when the guide is at the open position,
 wherein the driven roller is separated from the drive roller when the guide is at the open position.   
     
     
         9 . The sheet conveying device according to  claim 8 ,
 wherein the restrictor includes a shaft penetrating the driven roller.   
     
     
         10 . The sheet conveying device according to  claim 9 , further comprising a rotator including a contact portion to which a leading end of the sheet contacts at a portion upstream, in the sheet conveyance direction, from a conveyance nip region formed by causing the driven roller to contact the drive roller,
 wherein the rotator rotates while correcting skew of the sheet, and   the shaft includes a rotary shaft to which the rotator is fixed.   
     
     
         11 . An image forming apparatus comprising:
 the sheet conveying device according to  claim 1  to convey the sheet; and   an image forming device to form an image on the sheet conveyed by the sheet conveying device.