Listelli fusibili  Fabbricanti, Commercianti, Fornitori

To protect against risks at shearing and crushing edges, safety sensitive edges are employed.
Machinery and devices presenting dangerous movements must be provided with an emergency stop device. This device is monitored by a suitable safety relay unit.
Our safety edges are built up of mechanically opening N/C contacts connected in series, in the form of a contact chain. Current conducting contact rollers and insulating intermediate elements (wedge rollers) are alternately lined up on an expander cord. By pretension, the contact rollers are pressed together, and the current circuit is made.
Actuation of the safety edge leads to at least one pair of the contact rollers to separate by action of the wedge-shaped intermediate elements, and the current circuit is broken.
Due to the positive break of the supply, transformation of the output signal is not required, since a circuit interruption signal is directly available. This signal is fed to the safety relay unit already needed for the E-stop button.
Note: Wiring of the contact chain is performed in identical way as of an E-stop button.
The sensor part of the safety edge is positioned directly behind the front portion of the rubber profile. Separation of the contact position does not rely on a bending of the contact chain, but on the re-direction of the external radial forces to internal axial forces.
Actuation will commence at low actuating forces and after a very short response travel, providing a fast response time. The full remaining height of the rubber profile is available as an over-travel. In particular with regard to the prevention of injuries, large over-travels are of enormous importance for a safety sensitive edge.
 Because of the rotationally symmetrical design of the contact chain, our edges can theoretically be operated from any direction, that is, their sensitive range covers 360°. The contact chain-type safety edge in a correspondingly designed configuration meets category 3 of DIN ISO EN 13849-1 – even the sensor part. Double-channel design or redundancy is not necessary for this system, since the failure mode analysis made by the German test house BG has shown: a single fault does not lead to a loss of the safety function. This permits a simple construction of the system. At singly occurring faults, the system immediately changes to the safe condition: it switches off. If for instance in a safety edge a not perfect gluing of the end caps has been made, or sealing becomes worse because the glue becomes brittle, any ingress of insulating matter such as dust and dirt will not lead to a loss of the safety function.

Safety Rails
SSZ-Safety Rails consist of a hollow-chamber rubber profile with an integrated SSZ-sensor element. A signal is generated in the controler by an actuating force acting on the safety rail.
Selction criteria for the rubber profile of an SSZ-safety rail are the material specifications and the desired deformation distances.