Sheet takeout method

1 . A sheet takeout method performed by a sheet takeout device for taking out a topmost sheet member from among a plurality of sheet members horizontally placed on a placement station in a pre-stacked state, wherein

the sheet takeout device comprises:

a restraint device that comprises a restraining blade for restraining the plurality of sheet members from an upper side of a stacking direction thereof, is arranged on a side of the placement station, and is configured to be able to switch between a restrained state for restraining the plurality of sheet members by the restraining blade from the upper side of the stacking direction and a non-restrained state for retracting the restraining blade from the upper side of the plurality of sheet members and releasing the restraint by the restraining blade; and

a transfer device that comprises a transfer plate including a plurality of pickup and holding parts for picking up and holding the topmost sheet member from the upper side of the stacking direction in which the plurality of sheet members are stacked, is arranged so as to be opposed to the restraint device in a short direction of the sheet member with the placement station therebetween, and is configured to be able to switch a state of the transfer plate between a horizontal state in which the transfer plate is opposed to the topmost sheet member so as to be parallel thereto and an elastically deformed state in which an elastically deformable elastic deformation part including the pickup and holding part arranged in one end side or both end sides of the sheet member in a longitudinal direction that is orthogonal to the short direction is elastically deformed so as to deflect upward, and

the sheet takeout method comprises:

a first process of pressing, when the restraint device is in the restrained state, the transfer plate which is in the horizontal state against the topmost sheet member from the upper side of the stacking direction in which the plurality of sheet members are stacked to pickup and hold the topmost sheet member;

a second process of pressing, after the first process, the plurality of sheet members from the upper side of the stacking direction by an inelastic deformation part of the transfer plate which is in the elastically deformed state while setting the restraint device to be in the non-restrained state and setting the transfer plate to be in the elastically deformed state;

a third process of inserting, after the second process, the restraining blade into a space formed between the topmost sheet member and a sheet member provided below the topmost sheet member by setting the transfer plate to be in the elastically deformed state in the second process, and setting the restraint device to be in the restrained state again;

a fourth process of returning, after the third process, the transfer plate that has picked up and held the topmost sheet member to the horizontal state while retracting the transfer plate upward; and

a fifth process of transferring, after the fourth process, the topmost sheet member picked up and held by the transfer plate to a receiving holder.

2 . The sheet takeout method according to claim 1 , wherein

the sheet takeout device comprises:

a plate deformation mechanism for elastically deforming the elastic deformation part, and

the plate deformation mechanism comprises:

a tension mechanism which applies a tensile force to a wire member whose front end is attached to the pickup and holding part located in the elastic deformation part, which is opposite to the inelastic deformation part, or a cam mechanism which converts a power of a drive mechanism into an operation of advancing and retracting the pickup and holding part located in the elastic deformation part, which is opposite to the inelastic deformation part.

3 . The sheet takeout method according to claim 1 , wherein the transfer plate is configured to elastically deform, in the elastically deformed state, by no more than a predetermined amount to limit a bending amount of the sheet member picked up and held by the transfer plate which is in the elastically deformed state.

4 . The sheet takeout method according to claim 1 , wherein

the transfer device comprises a pair of the transfer plates, and

the transfer device is configured to be able to perform:

a first takeout state in which, while the first process, the second process, the third process, and the fourth process are performed by one of the transfer plates, the fifth process is performed by the other transfer plate; and

a second takeout state in which the fifth process is performed by one of the transfer plates while the first process, the second process, the third process, and the fourth process are performed by the other transfer plate.