When there’s a fire, or you need to stop a train in an emergency, you are often supposed to crack a pane of emergency glass. This can be confusing, time wasting and a possible source of injury in itself. It is also possible to activate accidentally by bumping into it.
Today’s invention is to replace all such switches with a modified drinks can ring-pull.
The top of such a can would be embedded in a backplate and an electrical ribbon pasted onto the rear surface of the metal so that when the ring is pulled, the ribbon on its back face is snapped -generating an electrical signal (to eg call the fire brigade or alert Underground platform staff).
This is an intuitive, common interface and operable by anyone without much force or required dexterity. It’s also cheap and tamper-evident. For anyone concerned about misuse, the aperture caused by pulling the ring could reveal a small networked camera lens which, by that stage, would have recorded the user’s face.