Saddle stitcher with a variable chain pitch

The invention relates to a saddle stitcher (1) for collating signatures (16, 18, 20) of paper, paperboard and the like for stapling the collated signatures (30) and for laying the stapled signatures (32) comprising a collecting line (34), a stapling station (24) and a delivery station (29). The stitching station (24) has a stitching carriage (107) with at least one stitching head (26) and the stitching carriage (107) is moved during the stitching process with the speed of the collated signatures (30) by a stitching carriage drive (140). Between stitching carriage drive (140) and stitching carriage (107) is a circuit unit (160) arranged to adapt the stitching carriage movement to the collecting chain pitch (G, K), that is for adjusting the horizontal stroke movement of the stitching carriage ((24) and for adjusting the horizontal distance from the stitching carriage 24) and delivery station (29).