Press safety control with back-up brake - has press operation prevented if either brake is inoperative

摘要

The safety control is used for an eccentric press with a double-handed operating circuit. The main brake is operated manually and a safety back-up brake is associated with it, controlled via the control source for the main brake and a relay. The back-up brake is switched directly, during the downwards stroke of the press, via a monitored contact of the output relay of the double-handed operating circuit and a contact of a relay controlled by a monitor for the braking moment. Both brakes are checked during each stroke of the press, to prevent further operation of the latter if either is inoperative.