A locking device (10) includes an adjustable bracket (7) provided with a recess (16), a stationary contour (9) with a contact surface (12), a pin (8), which is arranged movably in the recess (16) and on which an axial spring force generated by a compression spring (21) acts. A pin head (14) projects from the recess (16) of the bracket (7) and has a contact pair with the contact surface (12). At least one centering device (18) is provided between the pin (8) and the bracket (7). The locking device has a centering device (18), which has an elastically deformable ring (19). The ring (19) is arranged between the pin (8) and the bracket (7) within the recess (16) and is displaceably arranged within the recess (16). The ring (19) has a surface (22) with a cross section tapering against the direction of the force of the compression spring (21). The surface is in contact with a complementary surface (23) at the pin (8).