Transponder-coded system CES guarrantes comprehensive safety

Modern requirements for manual workplaces and partially automated production systems are highly diverse. For one thing, applicable standards and safety requirements must be met. For another, productivity must be steadily increased. In addition to the best possible ease of use, the requirements for safety of the operating personnel are crucial. Protecting installations and machines from expensive damage and avoiding costly downtimes are also essential. Necessary measures to protect against unforeseeable situations are thus important, given that they make a decisive contribution to ensuring long machine operating times and protect the mostly not insignificant capital investments. One possibility for ideal protection of these workplaces is now offered by Strasser GmbH from Weingarten with its safety lifting pillar. They are equipped not only with a dynamic servo motor with integral position control, but also with the proven MecLock safety system. The lifting columns are used in assembly stations, manual workplaces or test units. The technology, which reliably prevents activation of the danger zone when the protective field is not closed, is provided by EUCHNER from Leinfelden-Echterdingen.

Functional principle of the MecLock safety lifting pillar

Photo by EUCHNER

The MecLock system is an inherent safety concept based on a purely mechanical stop system that complies with Machinery Directive 2006/42/EC and stops the safety lifting pillar without overrunning. The anti-trapping protection is realized without electronics or control signals, and its function is therefore 100% ensured even in the event of a complete power failure. During machine loading operations, it is necessary to close movable safety guards quickly and safely. The protective field of the safety lifting column is electrically driven for this purpose. If the protective field detects the operator during the closing process, the actuating bar along the entire lower edge perimeter immediately triggers the stop system. In this process, the drive is disengaged and the stop mechanism is triggered in a single step. The protective field stops at the height of triggering by the actuating bar without overrunning. The following process cannot be started, because the actuator of safety system CES is fastened on the protective field and therefore cannot reach the operating distance of the read head. Trapping of the operating personnel is thereby prevented at all times, even at extremely high closing speeds of up to 2 m/s. On the return stroke of the drive, the protective field is automatically engaged again and moved to the open initial position.

Transponder-coded safety system CES

The transponder-coded CES systems, of which either one (closed polling) or two (open and closed polling) are installed, reliably detect whether the protective field of the safety lifting pillar is closed or open. Strasser chose the non-contact safety systems because of their high resistance against oscillation/vibration and the high number of actuations combined with a PLC control system. A CES system consists of three components: a read head, an actuator and an evaluation unit. The very slim design of the read head and actuator permits simple, space-saving installation within the safety lifting column frame. The signals themselves are evaluated by the evaluation unit, which is typically located in the control cabinet of the system to be protected. Compared to mechanical safety switches, the transponder coding of the CES system offers absolute protection against tampering. Each actuator possesses a unique code that cannot be reprogrammed. Thanks to wear-free activation of the read head by the actuator, the service life of both components is unlimited. The transponder used is securely potted in the housing and therefore insensitive to external influences. The approach direction to the actuator can be varied according to the application. The wiring work is minimized thanks to the simple connection with a plug connector.

Photo by EUCHNER

Safe position sensing

The two read heads are respectively mounted on the upper and lower ends of the stationary frame, and the actuators are fastened on the protective field. If the protective field is closed and the actuator is detected by the read head, the safe outputs of the evaluation unit are switched and the next process is started. The safety switches that Strasser previously used in the safety lifting pillars met the requirements of Performance Level PLd/Cat. 3.

However, since the CES products have been in use, the customer can design its protective field position polling system to be even safer. In combination with the corresponding evaluation unit, the Performance Level PLe/Cat. 4 of the CES system family guarantees a very safe polling managing partner of Strasser, is highly satisfied: “The Euchner safety switches we offer our customers as standard feature the best performance portfolio compared to competitors’ products.” system from the safety experts from Leinfelden-Echterdingen. Alex Strasser, managing partner of Strasser, is highly satisfied: “The Euchner safety switches we offer our customers as standard feature the best performance portfolio compared to competitors’ products.”

For further information visit www.euchner.de

• CID: 14558