Abstract: A method and apparatus for monitoring the application of glue onto the back of a book block processed in a book binding machine and bound by gluing, wherein the thickness of glue application is measured. At least the glue layer applied to the book block back travels partially through at least one measuring range formed by a ray bundle and directed transversely of the travel path of the book blocks. The apparatus includes a transmitter and corresponding receiver which together operate as a measurement transducer. The transducer forms a measuring range extending transversely of the travel path of a book block. The transmitter and receiver are arranged in the book binding machine and the book blocks are moved past the measuring range in such a way that at least the glue layer applied to the book block back partially extends into the measuring range.

Abstract: An inserting machine has a plurality of successively arranged feeder heads mounted along two parallel travel paths. In a main jacket feeding station, main jackets are inserted fold first into the feeder heads. The main jackets are opened and one or more insert feeding stations insert inserts into the main jackets. For increasing the output of the inserting machine, the insert feeding station is constructed for selectively feeding inserts to the feeder heads of both parallel travel paths.