Sheet conveyance apparatus and image forming apparatus

Abstract

A sheet conveyance apparatus includes: a pair of conveyance rollers having a first conveyance roller and a second conveyance roller and configured to convey a sheet; a support member configured to support the first conveyance roller; an openable and closable member configured to support the second conveyance roller and pivotable with respect to the support member so as to make the second conveyance roller contact with and separate from the first conveyance roller; a locking protrusion provided on the support member; and a locking member provided to be pivotable with respect to the openable and closable member and lockable to the locking protrusion so as to hold the openable and closable member in a closed position in which the second conveyance roller contacts the first conveyance roller. The locking protrusion or a part of the locking protrusion to which the locking member locked is rotatable.

What is claimed is: 
     
         1 . A sheet conveyance apparatus, comprising:
 a pair of conveyance rollers having a first conveyance roller and a second conveyance roller and configured to convey a sheet in a sheet conveyance direction;   a support member configured to support the first conveyance roller;   an openable and closable member configured to support the second conveyance roller and pivotable with respect to the support member so as to make the second conveyance roller contact with and separate from the first conveyance roller;   a locking protrusion provided on the support member; and   a locking member provided to be pivotable with respect to the openable and closable member and lockable to the locking protrusion so as to hold the openable and closable member in a closed position in which the openable and closable member is closed with respect to the support member so that the second conveyance roller contacts the first conveyance roller,   wherein the locking protrusion or a part of the locking protrusion to which the locking member locks is rotatable.   
     
     
         2 . The sheet conveyance apparatus according to  claim 1 , comprising a plurality of pairs of the conveyance rollers. 
     
     
         3 . The sheet conveyance apparatus according to  claim 1 , further comprising an urging unit configured to urge the locking member so that the locking member locks to the locking protrusion or the part of the locking protrusion. 
     
     
         4 . The sheet conveyance apparatus according to  claim 1 , wherein the openable and closable member is pivotable about a first pivotal axis extending in a width direction orthogonal to the sheet conveyance direction at one end portion of the openable and closable member in the sheet conveyance direction, and
 wherein the locking member is pivotable about a second pivotal axis extending in the width direction at the other end portion of the openable and closable member opposite to the first pivotal axis in the sheet conveyance direction.   
     
     
         5 . A sheet conveyance apparatus according to  claim 4 , wherein a handle to be grasped when a user opens/closes the openable and closable member is provided to be pivotable about the second pivotal axis extending in the width direction at the other end portion of the openable and closable member. 
     
     
         6 . A sheet conveyance apparatus according to  claim 5 , wherein a direction in which the handle is pivoted in order to release the locking member from the locking protrusion is the same as a direction in which the openable and closable member is pivoted from the closed position to an open position, and
 wherein the user can release the locking member from the locking protrusion and pivot the openable and closable member from the closed position to the open position by one operation of the handle.   
     
     
         7 . A sheet conveyance apparatus according to  claim 5 , wherein the handle is provided at one end portion of a pivot shaft extending in the width direction, and
 wherein the locking member is provided at the other end portion opposite to the one end portion of the pivot shaft.   
     
     
         8 . A sheet conveyance apparatus according to  claim 5 , wherein the handle is provided at one end portion of a pivot shaft extending in the width direction, and
 wherein the locking member is provided at each end portion of the pivot shaft.   
     
     
         9 . A sheet conveyance apparatus according to  claim 7 , further comprising an opening and closing auxiliary unit provided at the other end portion of the openable and closable member and on a side opposite to a side on which the handle is provided in the width direction, the opening and closing auxiliary unit being configured to urge the openable and closable member in a direction in which the openable and closable member is closed. 
     
     
         10 . A sheet conveyance apparatus according to  claim 1 , further comprising:
 a pressing unit configured to press the second conveyance roller against the first conveyance roller; and   a pressing force adjustment unit configured to adjust a pressing force by which the pressing unit presses the second conveyance roller against the first conveyance roller,   wherein the pressing force adjustment unit reduces or releases the pressing force of the second conveyance roller against the first conveyance roller when the openable and closable member is closed from an open state to the closed position, and   wherein the pressing force adjustment unit holds the pressing force of the second conveyance roller against the first conveyance roller at a predetermined value when the openable and closable member is held in the closed position.   
     
     
         11 . A sheet conveyance apparatus according to  claim 1 , wherein a pivotal axis of the locking member is parallel to a pivotal axis of the openable and closable member. 
     
     
         12 . An image forming apparatus comprising:
 an image forming section configured to form an image on a sheet; and   a sheet conveyance apparatus configured to convey the sheet before or after forming the image on the sheet by the image forming section,   the sheet conveyance apparatus, comprising:
 a pair of conveyance rollers having a first conveyance roller and a second conveyance roller and configured to convey the sheet in a sheet conveyance direction; 
 a support member configured to support the first conveyance roller; 
 an openable and closable member configured to support the second conveyance roller and pivotable with respect to the support member so as to make the second conveyance roller contact with and separate from the first conveyance roller; 
 a locking protrusion provided on the support member; and 
 a locking member provided to be pivotable with respect to the openable and closable member and lockable to the locking protrusion so as to hold the openable and closable member in a closed position in which the openable and closable member is closed with respect to the support member so that the second conveyance roller contacts the first conveyance roller, 
 wherein the locking protrusion or a part of the locking protrusion to which the locking member locks is rotatable.