| 摘要 |
The apparatus comprises guide rollers (3a, 3b), forcing tools (4a, 4b) as well as press halves (7a, 7b) for a rung (6) to be secured, to which press halves are connected powered actuators (8a, 8b). The location of a ladder blank is determined in the lateral direction with respect to the forcing tools (4a, 4b) by means of the press halves (7a, 7b) in such a way that the powered actuator (8a) of the half (7a) is placed in its extreme position and the weaker powered actuator (8b) of the press half (7b) guides the half (7b) against the other half (7a). Correspondingly, a cell inductive in the longitudinal direction detects the rung and stops the motion in the longitudinal direction of the belt. Subsequently, the forcing tools (4a, 4b) force the rung (6) close to the rail of the ladder blank (2) by bending the material of the rung away from its longitudinal centre line and form rivet-like joints against the rail, which rail is supported on a shoulder formed in the rung (6) earlier.
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