Scissors-type linkage assembly

A scissors-type linkage assembly for a key device, comprising:

• a first lever having a lever body and a pivot shaft that protrudes laterally from said lever body, said pivot shaft having at least one arcuate portion with a curvature centered at an axis of said pivot shaft, and at least one non-arcuate portion connected to said arcuate portion, said arcuate and non-arcuate portions being rotatable about the axis of said pivot shaft;
• and
• a second lever formed with a pivot hole that receives said pivot shaft and that has a rounded hole portion centered at said axis of said pivot shaft, and a non-rounded hole portion;
• said arcuate portion contacting slidably and rotatably a hole-defining wall of said rounded hole portion, said non-rounded hole portion being wider than said non-arcuate portion, said non-arcuate portion being movable toward or away from a hole-defining wall of said non-rounded hole portion and being capable of limiting an angle of rotation of said pivot shaft when contacting said hole-defining wall of said non-rounded hole portion.