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.
SSZ-safety rails are available in oil-resistant quality NBR and ozone-resistant quality EPDM.
The safety rails are taylor-made to customer specifications up to a length of 6.000 mm and are fitted as standard in an aluminium C-profile for mounting..
To protect persons against risks of this kind, pressure sensitive safety mats are employed. At devices such as machines, machining centres, presses, robot cells, high-shelf warehouses and many others, safety mats immediately switch off the power source, when the mat is stepped on. As long as the person stays on the mat, the machine cannot be set back into operation.
The HSM Safety Mat uses mechanical positive-break contacts. Therefore, an additional safety control unit is not needed.
Our safety mats are built up of mechanically opening break contacts connected in series, in the form of a contact mat (see also our catalogue HSC Safety Edges). Current conducting contact plates and insulating wedge elements are alternately lined up on an expander cord. By pre-tension, the contact plates are pressed together, and the current circuit is made. When stepping on the safety mat, at least one of the contact plate pairs is separated by action of the wedge elements, and the current circuit is broken (see fig. bottom right).
Thus, a 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. This means: wiring of the contact chain is performed in identical way as of an E-stop button. The number of lined-up contact plates and wedge elements depends on the size of the safety mat.
The contact mat is placed between rubber mats being sealed at their borders by profiles. The surface structure depends on customer's wishes or the requirements in use. The safety mats are manufactured in the sizes as specified by customer (max. & min. sizes see specification). Larger protection areas are achieved by several mats connected together.
A special evaluator is not required, since the contact mat is composed of electro-mechanical break contacts, the signal of which can immediately be further processed. In addition to cost saving, any expensive connection and wiring actions are unnecessary. Valuable space is won on the crowded control panel.
Further, of course, a not existing device cannot go wrong.
Moreover, use of a break contact guarantees a high safety level.
At singly occurring faults, the system immediately changes to the safe condition: it switches off.
Our safety mat meets the requirements of 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 BG has shown: a single fault does not lead to a loss of the safety function. This permits a simple construction of the system.