INOX PATENT 18cm Italian Ackermannchen style black automatic knife

Vintage Italian automatic knife stamped INOX PATENT on the ricasso (tang). This style is often found with the Ackermannchen stamp and I don't know of any other name for this style, so I'm going with that. As far as I can see the markings are the only difference. The knife measures just under 17.6cm (7 inches) open with brass liners and nickel silver plated button and safety cap. The flat grind swedge blade is nearly full (99%) with some of the original factory finish and some scratches from sharpening/use. The black synthetic scales are in good condition with no cracks or shrinkage with some handling marks/light scratches. The knife works great with the blade tip even with the liners closed, good snap and very good lockup open. This is a backspring release knife so you press on a grooved tab on the exposed backspring in the wrap around handles to release the blade to be closed. Safety does not work properly. VG+ condition.