The invention relates to a rear stop unit (7) with a stop and/or gripping and/or measuring element (10) for positioning a sheet (3) to be machined on a bending press. The stop and/or gripping and/or measuring element (10) is arranged on an adjustable bearing arm (13) by means of a pivot joint (12). The bearing arm (13) is connected to a guide rail (20) by means of an additional pivot joint (18) via a guide element (19). The rear stop unit (7) further comprises a support arm (21) which is connected to the bearing arm (13) via a joint (22) and to an additional guide element (24) via a rigid connection, and the support arm is connected to the guide rail (20) via the additional guide element. Furthermore, the joint (22) is designed as a rotational/prismatic joint. The position of the bearing arm (13) can thereby be adjusted by moving the support arm (21) in a linear manner along a guide direction (11) specified by the guide rail (20).
