The type of safety technology, including the required performance level, that must be used in machines and systems is determined by the Machinery Directive and binding standards such as EN ISO 13849-1 and EN ISO 14119. These standards determine when, for example, guard locking with or without transponder coding should be selected.

On the one hand, guard locking devices provide personal protection: they ensure that people are not put at risk during subsequent, dangerous movements. On the other hand, they protect the process, as guard locking effectively prevents employees from simply opening guards, which would lead to machine downtimes and thus to a loss of productivity.
To avoid unnecessary downtime from the outset, machine manufacturers are increasingly using guard locking devices, even if they are not required in some cases in accordance with EN ISO 14119. The installation of a transponder-coded guard locking with a high level of protection can also be the right choice after a machine has been converted or retrofitted - for example, to meet the updated requirements of a risk assessment and thus be able to continue to produce safely in the future. Guard locking devices with transponder coding offer a high level of protection against tampering.

If small doors and flaps on machines are to be safeguarded with protective devices, designers often favor compact switches and safety systems - on the one hand because installation space is usually limited, and on the other hand because machine design aspects play a special role in many industries. Ideally, safety switches should therefore be able to be installed in such a way that they are almost invisible.

Inconspicuously integrated

Euchner has developed the 'CTM' series in collaboration with end users to meet these requirements. The devices are among the smallest transponder-coded switches with guard locking and, thanks to their dimensions of 120 mm x 36 mm x 25 mm, can be integrated inconspicuously into the housing or enclosure of machines. Their design makes them ideal for use in small or lightweight doors and flaps. An elastomer-mounted ball actuator also makes it possible to secure doors with small swing radii from 150 mm.

Despite its compact design, the switch offers safety gate protection to Cat. 4/PL e in accordance with EN ISO 13849-1 and therefore meets the highest level of protection for people and machinery.
In the event of a power failure or when the system is switched off, the bistable guard locking function of the guard locking always ensures a high level of protection, as the system remains in its current state in these cases: if the guard locking of the switch was previously activated, the door remains securely locked. If the guard locking was deactivated, the door can still be opened and closed again. This virtually eliminates the possibility of people being locked in unintentionally.
The system offers a high coding level. In addition, its locking force of 1000 N is sufficient for many applications. Typical applications include case packers and dosing, filling and sealing machines in the packaging industry, as well as 3D printers, blow molding machines for the plastics processing industry and smaller doors and flaps on machine tools.