Leaf Spring Automatic - Automatic Opening Systems

Leaf Spring Automatic Info

Leaf Spring automatics are often lever operated like the Mikov, or button or bolster/scale released like the Butch Valloton Dual Action automatics. The Leaf spring automatic is ideal for Dual Action knives because the spring does not have to be an integral part of the knife opening process like a coil spring automatic does. This way, the knife blade can be opened without releasing the leaf spring.

The Leaf Spring automatic is an older design than a coil spring automatic, but is in general more reliable and less prone to breakage. Leaf Spring automatics in general tend to fire a bit slower, however.

How it Works

Depending on the type of leaf spring auto, the mechanism is slightly different. In general however, there is either a lever or button that releases the parabolic leaf spring, either directly or by releasing the blade, which is loading the spring as in the case of a Mikov. The tang of the blade loads the spring and the blade is held in place by the lever. Once the lever is lifted, the spring is released, and the blade spun open by the force of the spring.

With D/A (dual action) automatics, the button or lever will usually directly release the spring without any interaction with the blade. This allows the blade to be open independently from the automatic spring allowing it to have D/A functionality. When the automatic feature is used, the leaf spring pushes against the tang and spins the knife open.

The diagram below shows roughly where the parabolic shaped leaf spring is located on the knife. It is number 52 in the diagram.

Leaf Spring Pictures