Paper sheet stacking apparatus

A paper sheet stacking apparatus for stacking paper sheets upright comprising:

• bottom plate for stacking paper sheets being led upright;
• a the bottom plate for stopping paper sheets led to the a side plate mounted above bottom plate;
• a rotary member mounted above the bottom plate and having at least an intermittent member rotated to intermittently contact the paper sheets being led to the bottom plate and to position the paper sheets proximate to the side plate;
• a support member facing the rotary member and preventing the paper sheets being led upright from turning down onto the bottom plate, wherein said bottom plate is slanted such that the paper sheets led into the apparatus are guided toward the support member;
• a first spring member having a first spring strength and a second spring member having a second spring strength that pull the support member toward the rotary member, said first spring strength being lower than said second spring strength;
• and
• a stopper disposed for determining the position at which the second spring member becomes active when a force or the stack due to volume increase thereof exceeds the first spring strength of the first spring member.

A method for stacking paper sheets, comprising:

• leading paper sheets onto a bottom plate for stacking said sheets in an upright position;
• stopping said paper sheets led onto the bottom plate with a side plate mounted above the bottom plate;
• intermittently contacting the paper sheets being led to the bottom plate with a rotary member to position the paper sheets proximate to the side plate;
• preventing, with a support member, the paper sheets being led to the bottom plate from turning down onto the bottom plate;
• changing a distance between the support member and the rotary member;
• forcing the support member toward the rotary member;
• and
• slanting the bottom plate such that the paper sheets stacked onto the bottom plate are guided toward the support member.