Sheet feeding apparatus and image forming system

Abstract

There are provided a sheet feeding apparatus and an image forming system that can horizontally maintain a posture of the topmost envelope in stored envelopes, by a simple configuration. The sheet feeding apparatus includes: a stacking portion; a conveying portion; and lifting members. A length of the stacking portion in a width direction perpendicular to a conveying direction of envelopes and also perpendicular to a vertical direction thereof is shorter than a length of each of the envelopes. The lifting members lift end portions of the upstream side of the envelopes in the conveying direction, upward in the vertical direction.

What is claimed is: 
     
         1 . A sheet feeding apparatus comprising:
 a stacking portion on which a plurality of envelopes with a predetermined size can be stacked, the stacking portion having a length in a width direction perpendicular to a conveying direction of the envelopes with the predetermined size and also perpendicular to a vertical direction thereof being shorter than a length of each of the envelopes with the predetermined size in a width direction;   a conveying portion that conveys the envelopes with the predetermined size arranged at a top of the plurality of envelopes with the predetermined size in the vertical direction, the envelopes being stacked on the stacking portion; and   a lifting member that lifts end portions of the upstream side of the envelopes with the predetermined size in the conveying direction, upward in the vertical direction, the envelopes being stacked on the stacking portion.   
     
     
         2 . The sheet feeding apparatus according to  claim 1 , further comprising an elevating portion that can be elevated in the vertical direction, wherein
 the stacking portion is detachably provided at the elevating portion.   
     
     
         3 . The sheet feeding apparatus according to  claim 1 , wherein the lifting member is provided at the stacking portion. 
     
     
         4 . The sheet feeding apparatus according to  claim 3 , wherein the lifting member is movably supported by the stacking portion along the conveying direction. 
     
     
         5 . The sheet feeding apparatus according to  claim 4 , wherein a height of the lifting member in the vertical direction changes corresponding to the conveying direction in the stacking portion. 
     
     
         6 . The sheet feeding apparatus according to  claim 1 , wherein a height of the lifting member in the vertical direction changes in accordance with the number of the plurality of envelopes with the predetermined size stacked on the stacking portion. 
     
     
         7 . The sheet feeding apparatus according to  claim 6 , wherein
 the lifting member includes:
 a supporting portion that comes into contact with the envelopes; and 
 an elastic portion that is elastically deformed due to self-weight of the plurality of stacked envelopes with the predetermined size. 
   
     
     
         8 . The sheet feeding apparatus according to  claim 1 , further comprising an air blowing portion that blows air to the plurality of envelopes with the predetermined size stacked on the stacking portion, from both sides in the width direction. 
     
     
         9 . The sheet feeding apparatus according to  claim 8 , further comprising a control portion that controls an air quantity of the air blowing portion in accordance with the number of the envelopes stacked on the stacking portion. 
     
     
         10 . An image forming system comprising:
 an image forming apparatus that forms an image on envelopes with a predetermined size; and   a sheet feeding apparatus that feeds the envelopes to the image forming apparatus, wherein   the sheet feeding apparatus includes:
 a stacking portion on which a plurality of the envelopes with the predetermined size can be stacked, the stacking portion having a length in a width direction perpendicular to a conveying direction of the envelopes with the predetermined size and also perpendicular to a vertical direction thereof being shorter than a length of each of the envelopes with the predetermined size in a width direction; 
 a conveying portion that conveys, to the image forming apparatus, the envelopes with the predetermined size arranged at a top of the plurality of envelopes with the predetermined size in the vertical direction, the envelopes being stacked on the stacking portion; and 
   a lifting member that lifts end portions of the upstream side of the envelopes with the predetermined size in the conveying direction, upward in the vertical direction, the envelopes being stacked on the stacking portion.