Patent ID: 7920820

Claim:
A bookbinding apparatus comprising: collecting means on which sequentially fed sheets are collected into a sheet bundle; a bookbinding path along which the sheet bundle from the collecting means is sequentially supplied for bookbinding; bundle conveying means located on the bookbinding path for transferring the sheet bundle to a paste applying position and then to a cover binding position; paste applying means located at the paste applying position for applying an adhesive to a spine part of the sheet bundle; a cover feeding path crossing the bookbinding path to feed a cover sheet to the cover binding position; cover binding means located at the cover binding position for binding the sheet bundle with the adhesive applied thereto, to the cover sheet; and cover binding control means for controlling the cover binding means, wherein the cover binding means comprises back folding press members folding back the cover sheet placed on the spine part of the sheet bundle at the cover binding position so that the cover sheet is attached onto the sheet bundle, and a back abutting plate member backing up the cover sheet, the back abutting plate member is located below the back folding press members so that the cover sheet is sandwiched between the back abutting plate member and the spine part of the sheet bundle with a small gap formed between the back abutting plate member and the spine part, the gap between the back abutting plate member and the sheet bundle spine part at the cover binding position being adjustable in size, and the cover binding control means adjusts the size of the gap between the back abutting plate member and the sheet bundle spine part depending on a thickness of the cover sheet when the cover sheet is folded back by the back folding press members.