Sheet conveying apparatus, sheet treating apparatus and image forming apparatus

Abstract

A sheet conveying apparatus provided with a pair of discharging rollers having a first roller and a second roller disposed in opposed relationship with the first roller, a roller supporting member which rotatably supports the first roller, and is movable between a first position in which the first roller can cooperate with the second roller to discharge a sheet and a second position in which the first roller is spaced apart from the second roller, a driving member which pivotally moves the roller supporting member, a drive transmitting portion which transmits drive to the driving member, and a single drive source which transmits the drive to the drive transmitting portion. The roller supporting member is provided with a cut-away tooth gear portion and a cam stopper portion, and the driving member has a cut-away tooth gear and a cam corresponding to the cut-away tooth gear portion and the cam stopper portion, respectively, of the roller supporting member, and by these, the movement of the roller supporting member from the first position to the second position and the movement of the roller supporting member from the second position to the first position are effected.

1 . A sheet conveying apparatus comprising: 
 a pair of conveying rollers having a first roller and a second roller disposed in opposed relationship with said first roller;    a roller supporting member which rotatably supports said first roller, and is movable between a first position in which said first roller can cooperate with said second roller to convey a sheet and a second position in which said first roller is spaced apart from said second roller;    a driving member which pivotally moves said roller supporting member;    a drive transmitting portion which transmits drive to said driving member; and    a drive source which transmits the drive to said drive transmitting portion,    wherein said roller supporting member has a gear portion, said driving member has a gear meshing with said gear portion of said roller supporting member, and a movement of said roller supporting member from said first position to said second position is effected by the meshing engagement between said gear portion and said gear.    
   
   
       2 . A sheet conveying apparatus according to  claim 1 , wherein said roller supporting member is provided with a cam stopper portion, said driving member has a cam corresponding to said cam stopper portion of said roller supporting member, a holding of said roller supporting member in said first position is effected by an engagement between said cam and said cam stopper portion, and a movement of said roller supporting member from said second position to said first position is effected by a release of a holding of the engagement between said cam and said cam stopper portion.  
   
   
       3 . A sheet conveying apparatus according to  claim 2 , wherein the movement of said roller supporting member from said first position to said second position and the movement of said roller supporting member from said second position to said first position are effected by a drive of said drive source only in one direction transmitted from said drive transmitting portion to said driving member.  
   
   
       4 . A sheet conveying apparatus according to  claim 1 , wherein at least one of said gear portion of said roller supporting member and said gear of said driving member is a cut-away tooth gear.  
   
   
       5 . A sheet conveying apparatus according to  claim 1 , wherein said gear portion of said roller supporting member is of such a shape that at least one of a second and succeeding teeth as counted from a tooth meshing with a tooth of said gear of said driving member at first is blank, and is of such a shape that a last tooth mesh with said gear of said driving member.  
   
   
       6 . A sheet conveying apparatus according to  claim 1 , wherein said gear of said driving member is of such a shape that at least one of a second and succeeding teeth as counted from a teeth meshing with a tooth of said gear portion at first is blank, and is of such a shape that a last tooth mesh with said gear of said driving member.  
   
   
       7 . A sheet conveying apparatus according to  claim 1 , further comprising a spring which biases said roller supporting member toward said first position.  
   
   
       8 . A sheet conveying apparatus according to  claim 1 , wherein a driving of said pair of conveying rollers is interrupted by the movement of said roller supporting member from said first position to said second position.  
   
   
       9 . A sheet conveying apparatus according to  claim 1 , wherein a driving of said pair of conveying rollers is transmitted from a pulley disposed at a center of rotation of said roller supporting member by belt driving.  
   
   
       10 . A sheet conveying apparatus according to  claim 1 , wherein when said pair of conveying rollers are in said first position, a plurality of roller members provided axially of said first roller are designed to come into between a plurality of roller members provided axially of said second roller.  
   
   
       11 . A sheet conveying apparatus according to  claim 1 , further comprising a paddle which effects alignment in a sheet conveying direction, wherein said drive transmitting portion is designed to selectively perform an aligning operation by said paddle, or a spacing operation of said first roller by said driving member, by forward and reverse rotation of said drive source.  
   
   
       12 . A sheet conveying apparatus according to  claim 11 , wherein said drive transmitting portion is held by a rocking member, and rocks said rocking member by the forward and reverse rotation of said drive source to thereby selectively transmit a drive of said drive source to said paddle or said driving member.  
   
   
       13 . A sheet conveying apparatus according to  claim 11 , wherein said drive transmitting portion has a first one-way clutch which transmits a drive only in one direction, and a second one-way clutch which transmits only drive in a direction opposite to that of said first one-way clutch, and selectively transmits a drive of said drive source to said paddle or said driving member by the forward and reverse rotation of said drive source.  
   
   
       14 . A sheet conveying apparatus according to  claim 11 , wherein said paddle is provided with a resilient paddle member which moves the sheet in an aligning direction while rotating about a rotary shaft.  
   
   
       15 . A sheet conveying apparatus according to  claim 11 , further comprising a sheet stamp member which presses an upper surface of the sheet and holds the sheet, wherein said sheet stamp member releases a sheet pressing operation in operative association with the aligning operation of said paddle.  
   
   
       16 . A sheet treating apparatus comprising: 
 a sheet conveying apparatus according to any one of  claims 1  to  6 ; and    a stapler which carries out a binding process to sheets.    
   
   
       17 . An image forming apparatus comprising: 
 an image forming portion which forms an image on a sheet; and    a sheet conveying apparatus according to any one of  claims 1  to  6 .