Due to local laws it's not a good idea to carry a locking blade. I've seen examples of slipjoint knives that don't lock but at the same time won't close in on somebody's hand when in use.

Picrel is a Böker Plus Worldwide, the mechanism can be seen here: https://www.youtube.com/watch?v=Mxk-U0zjGvU

Do you have any info on which type to look at? Or post yours.