Flipjoint

Flipjoint means the combination of the opening mechanism "flipper" and the locking method "slipjoint". "Flippers" are knives that have an extension at the base of the blade that allows you to open the blade with one hand by applying a little pressure with your finger. When you do this, they flip open quickly, almost as if they were spring-assisted. In Germany, this brings with it the fact that most of these knives are subject to the ban on carrying (§42a WaffG), as they can be locked in this way one-handed. In order to combine the practical opening mechanism with unrestricted carrying, flipjoint knives have a slipjoint lock. BKA notices of these knives do not consider slipjoint locks to be a "manual locking device". Slipjoint mechanisms hold the blade open by spring pressure, but do not lock it completely like a backlock, for example. This means that the blade can always be folded back in by applying moderate pressure to the back of the blade. Manual unlocking of the locking system is therefore not really done, the blade does not legally count as locked/fixed. The classic slipjoint usually has a back spring that acts on the blade base, everyone should know this from the Victorinox or Laguiole models. However, this would almost rule out the possibility of the blade flipping open. So an innovation has been applied to flipjoint knives: The spring force now comes from spring plates embedded in the side plates, which press a small metal ball, the so-called detend ball, into a recess in the root of the blade. This means that only a minimum of friction has to be overcome until the blade is fully opened, so the blade can be flipped open smoothly. Only in the recess do the balls exert so much pressure that the blade will not close again on its own. This now needs a little force on the back of the blade, so these knives are not suitable for stabbing, they would fold in. This mechanism also prevents the blade from swinging open when closed and damaging trouser pockets, but this is the case with almost all locking mechanisms.