DEVICE WITH YALE KEY
Device used by railway operators which locks point switches into the normal position by electrical disconnection from the relay interlocking.
The device’s lever, which is normally in the “released” position, will be moved to the “locked” position only after the relay interlocking impulse given by an inner electromagnet, allowing the lever to pass over the “waiting approval” position.
When the lever is in vertical position, the yale key can be extracted, locking the lever and preventing any movement of the point machine.
The point machine can be commanded by the relay interlocking only after the key re-positioning and the lever positioning on “released” status.
As long as the lever is in the “released” or in “waiting approval” status, the key remains locked into the device.
The device is insert in a watertight box (in aluminium or in fibreglass) mounted on a dedicated mast, installed in correspondence with station protection.