The Slide Lock is used on a number of 111mm model Victorinox knives. This mechanism has a small spring loaded metal shaft that is pulled "upwards." When the blade is opened, an area behind the base of the blade is exposed and the shaft clicks upward. After the shaft has moved into place it prevents the blade from rotating back down, and thus closing. On the side of the knife, built into the scale, is a gray slide approx. 1cm square that is used to Release the lock. When the Release is slid down the metal shaft behind the blade is pulled down, freeing the blade to rotate or fold closed.
An email from Victorinox in response to the Strength of the Slide Lock. Aug 2008
''The blade releases via the slider on the rear shell of the handle. It is comfortably and easy to operate and as you mentioned only for accidental closing. The bestsellers in this series are the Picnicker, Rucksack and the Outrider. The model Workchamp XL is aimed at knife collectors.
At the moment we are developing an improving the spring for the locking blade and slider system. During testing of an material sample the stress strain curve is a graphical representation of the relationship between stress,derived from measuring the load applied on the sample and strain derived from measuring the deformation of the sample i.e. elongation, compression, or distortion. Steel generally exhibits a very linear stress-strain relationship up to a well defined yield point. The linear portion of the curve is in the elastic region and the slope is the modulus of elasticity or Young`s modulus. A torque in physics, also called moment, is a vector that measures the tendency of a force to rotate an object about some axis(center). The magnitude of a torque is defined as the product of a force and the length of the lever arm(radius) M=FxI. To stay in the elastic region a torque of maximum 10,8Nm should not be exceeded.
However we found them to be insufficiently robust and sturdy for the fire brigades, the rescue services the police and army forces. For this reason we developed a knife (0,83-0,84) of the same shape and size but much stronger, with thicker rivets and blades, Liner-lock for the blade and powerful screwdriver. In this range you will find the Victorinox lock blade for one hand opening (e.g. Rescuetool ).''
Wenger original 120mm Ranger series models featured a liner-lock system. The lock on these models is released with a sliding button on the bottom scale, which pulls on the liner to disengage the lock. These were the first Swiss Army Knives to use a liner-lock mechanism.
The knives in Wenger 130mm series (originally known as the New Ranger series) employ a liner-lock to lock the main-blade. Release of this lock is accomplished by depressing the white and red Wenger cross on the side of the handle. The logo serves as the lock-release button, and on this model pushes the liner to disengage the lock.
Wenger uses their Packlock system on some 85mm knives. This system uses a notch on the backspring and a mating notch on the tang of the blade that interlock when the blade is opened. A lock-release button is positioned above the scale on the top of the knife, pressing the release pushes on the backspring to disengage the lock. This lock is not very secure, and is really more of a limited safety feature. This lock is prone to failure after use if original machining was no precise.
Some 65mm Wenger knives feature a locking knife blade that is interlocked with the nailfile tool. To release the lock, the nailfile must be opened to the 90 degree position.
The Wenger Pressure Lock system is locking-system they use with some of their screwdrivers. With this system the lock is automatically engaged when pressure is applied in the direction parallel to the knife/screwdriver when it in the open position. The lock is automatically released when the pressure is reduced.
See Also: SOSAK: Wenger Locking Screwdrivers Article, February 2nd, 2010