The STI Company has been designing and producing security devices for industry since 1894.

The solutions proposed by STI comply with standard safety rules and regulations, as they force the operator to respect each step of the safety process which has been designed. Each year STI invests more than 5% of its turnover in research and development of its products.

STI products are accepted industry-wide due to their simplicity and efficiency. STI systems are implemented in the fields of railway, power generation, chemical, petro-chemical, steel industry, food industry, etc...

Main products: include bolt locks, latch locks, rotary locks, keys panels, logistics locks, valve locks, lockable switches , safety switches, electrobolts, atex locks and accessories

THE KEY TRANSFER

“More than a principle ... The way forward to optimal safety”

Based on the idea that a key can not be in two places at the same time, our locking systems force operators to perform a predetermined sequence, particularly in relation to maintenance and operating requirements. In its most basic form, the key transfer principle involves the positive locking of the power source and access point of a machine, with locks operated by a single common key. Our extensive range of locks permits the locking of most control circuits, switchgear and access points.

By this method, you have the guarantee that all your hazardous work areas are protected with maximum security. This technology, considered the most effective form of industrial safety protection, can be completely automated. The system is also cost- effective as it is quick and easy to install.

In the example below, the interlocking system acts to disconnect and lock the power supply of the machine before allowing access to the area for any technical operation.

	Lock-1                                               Lock-2
Initial position : Machine IN SERVICE - The switch is ON - Lock 1, the bolt is retracted, the key is trapped - Lock 2, the access is locked in the OFF position - Access to the area is forbidden.
Position 1 : Machine is power OFF - The switch is OFF - Lock 1, the bolt is retracted, the key is trapped but manoeuvrable - Lock 2, the access is locked. - Access to the area is still forbidden..
Position 2 : KEY TRANSFER - The switch is OFF - Lock 1, the bolt is extended and blocks the drive of the switch. The key is free. - Key transfer from lock 1 to lock 2 - Lock 2, the access is locked - The machine power is OFF but access to the area is still forbidden.
Position 3 : Access authorized - The switch is still in the OFF position - Lock 1, the bolt is extended - Lock 2, the access is locked, the key is trapped but manoeuvrable - It is impossible to turn the power of the machine ON
Position 4 : Access to the area - The switch is still in the OFF position - Lock 1, the bolt is extended - Lock 2, the access is open, the key is trapped - The area is accessible for technical operation. It is impossible to turn the power of the machine ON