EDC604

Notches cut into each wheel will also be aligned. These notches form a gap that will allow the lock to release and open. Pin-and-tumbler locks are different, because they require a key to unlock them. Basic pin-and-tumbler locks have several spring-loaded pins inside a series of small cylinders. When the right key slides into a pin-and-tumbler lock, the pointed teeth and notches on the blade of the key allow the spring-loaded pins to move up and down until they line up with a track called the shear line. When the pins align with the shear line, the cylinder can turn and the lock will open.

Touch screens are used in all sorts of modern electronic devices, including personal digital assistants (PDAs), satellite navigation systems and video games. Their popularity has surged recently, but the idea for the touch screen goes back several decades.