Fortress Interlocks TK7 3 Position Key Switch

3 Position Key Switch

Introduction to mGard Trapped key interlocking is a tried and tested method of mechanically
safeguarding machines and processes.
Mechanical keys eliminate most of the electrical wiring associated with other types of interlocks making them cost effective to install.
The Fortress mGard is suitable for use up to SIL3 (IEC 62061) and Category 4 PLe (ISO 13849-1).
Why Interlocks?
Interlocks are mechanical, electrical or other types of devices, the purpose of which is to prevent the operation of hazardous
machine functions under specified conditions. Interlocking can be used to help protect personnel and equipment, enforce
processes, and improve productivity.
More information on interlock devices and their use on machinery can be found in ISO 14119, Safety of machinery - Interlocking
devices associated with guards - Principles for design and selection. Further information on trapped key interlocking can be
found in the technical specification ISO/TS 19837.
Why Mechanical?
• Mechanical interlocking can be used to control hazardous energy sources.
• A key from one isolation control device can be used in an intermediate transfer (key exchange) device to release keys for
multiple guards.
• Personnel keys released from access locks can be used to proactively prevent unexpected start up of machinery as per ISO
14118.
• Mechanical systems reduce wiring and fault masking risk.
Key Operated Switch
Key removed, contacts opened
Key Exchange Device
Access Lock
A key exchange device allows Key trapped, the intermediate transfer of actuator removed
keys within a system
2
Access Lock with Personnel Key
Access key trapped, personnel key removed, guard (door) open