Safety switching device

US4330810A · kind A · utility

Assignee

• L. Schuler GmbH · DE

Inventors

• Franz Schneider · Göppingen, DE
• Helmut Braitinger · Göppingen, DE

Key dates

• Filing date: Apr 18, 1980
• Grant date: May 18, 1982
• Expiry date: Apr 18, 2000

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B21D55/00
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

In automated systems such as press lines or related systems, a control circuit is typically designed to be intrinsically safe in acting on actuators which trigger movements of the presses. The actuators and/or the power amplifiers preceding them are connected to a load voltage supply circuit. In order to prevent unplanned movements during setting-up operations, when the safety circuits are partially disabled, which movements could be caused by a failure (e.g. fusing of a semiconductor component), the actuators and/or the power amplifiers preceding them are driven by the control circuit and are connected to the load voltage supply circuit by means of control keys, which trigger planned movements, via at least one zero-voltage-protected switching element.