Abstract: A case-in device of an adhesive bookbinder includes a base inside which two shafts are rotatably mounted to be driven by a motor to rotate in opposite directions. A binding platform is pivotally mounted to the base and has two clamping plates movably supported thereon. The platform has two elongated slots and two guide rails corresponding to the slots. Each of the guide rails has two slides slidably mounted thereon and each corresponding to and connected through the respective slot to each of the clamping plates. Each of the slides has a roller rotatably supported thereon. The shafts have lever arms fixed thereon and the arms are sized to be engageable with the rollers and thus driving the clamping plates toward each other to clamp and the apply a force to a book disposed therebetween for adhesively securing the book cover to the book.