I'm looking for a word to describe a built-in device that prevents the user from incorrectly using/operating the thing it is on.
e.g. A tilt and turn window has a device which prevents the user from turning the handle further when the sash is open which could make it drop out and fall on the person.
It removes the possibility/opportunity for a user to do something wrong that would cause the window/object to fail.
I've found
- "Faulty operation lock"
- "anti-mishandling device"
I find them unclear, sound unnatural and only appear on the websites of foreign companies (hence bad translations).
"Fail safe device" is ok, but I find it too vague in this context.
Any ideas?
Best Answer
The standard term used in all types of industry for this is an interlock.
Interlocks can be implemented with software, electrical circuitry, or by mechanical means.
An example of a software interlock is a piece of code which checks a number of variables before allowing a certain action to execute.
An electrical interlock is usually a chain of sensors, switches, or relays that have to be set in the correct state to allow an operation to take place. A common example is the sensors in elevator doors which prevent them from crushing a person when they sense someone is obstructing the door's automatic closing, or to prevent the doors from opening while the elevator is in motion or stopped between floors.
Mechanical interlocks are physical devices that prevent a mechanical system from entering an unwanted state. Locking bearings and corresponding grooves in the gear selector shafts of a manual transmission, for example, prevent more than one gear from being selected at a given time.
The linked wikipedia article is not entirely accurate - it suggests the term is more specific than it actually is in practice. For example, it says :
While I think in practice most engineers I know would certainly refer to such devices as interlocks, formally. The article's talk section has some good citations on the erroneous nature of that particular statement.