LINER LOCK
The locking-liner mechanism has been in the knife world for some time and it has gained in popularity over the past several years. If properly made they serve their purpose quite well however in order to work correctly they have to be made within fairly close tollerances. The basic principle is an integral locking bar within the knife liner being stress bent, enabling it to spring into position behind the rear tang of the blade when the blade is opened. The locking bar wedges against the rear of the blade, locking it open until you physically push it clear and close the blade. With little practice, the process of opening and closing the blade can be done single-handed.

LOCK-BACK
A basic, functional lock which although relatively simple and low cost to manufacture, provides a very solid blade lock. In practice the lock design positions a stop bar parallel to and in direct line with the blade at the upper back or rear tang of the blade to lock the blade open. Basically, as the blade is rotated open, the spring tensioned, center pivoted stop bar tracks around the circular portion of the blade tang until it drops or locks into the notched out tang. And to release the lock, the exposed portion of the stop bar in the handle back is depressed into the handle, pivoting the stop bar out, releasing the locked blade. This style of locking mechanism requires two hands to safely close the blade although you may still easily open the blade single-handed if desired.

One advantage of this style of lock is the blade remains under tension while closed thus preventing accidental opening.

AUTOMATIC OPENER
These are illegal in the UK.

The blade is deployed out from the handle side like traditional folding knives, but the blade is spring open assisted to a fully locked position.