seen and means for the production of burklock, forsedda with avrivningsnyckel forhindra framstellning of defective products

摘要

A metal can top rests on a tool seat for the purpose of riveting a pull-up ring to the metal can top. Riveting takes place with the aid of a dolly which moves back and forth relative to the tool seat. Transmitters are arranged in the tool seat to check that no foreign objects are present in it. Transmitters sense the movement of the dolly past a reference level as it moves towards the tool seat. In the riveting position the dolly presses the metal can top and associated pull-up ring against the tool seat, whereby the pull-up ring actuates a sensing pin and moves it to an indicating position which is sensed by a transmitter. The signals from the respective transmitters are received by a delay and control device. In the event of the presence of foreign objects in the tool seat, as well as in the event of an excessively long interval between the time the dolly passes the reference level and the time the sensing pin reaches the indicating position, the delay and control device actuates the drive device of the dolly, causing it to stop the movement of the dolly.