A knob closure device for operating and locking two surfaces which are axially movable with respect to the knob, which comprises: a pin that can be coupled to the first surface and is affected by two annular end grooves; a hollow body that can be coupled to the second surface and supports, so that they can move axially and rotate, the actuation knob on one side and a disengagement cylinder on the other side, the knob and the cylinder being mutually coupled; a central bushing, which is rigidly coupled to the hollow body and in which two oppositely arranged inclined slots are formed that converge toward each other and toward the free end of the bushing; two transverse shafts that are slidingly mounted in the slots and are pushed by a compression spring in tangential engagement in the annular grooves to couple the pin to the bushing; a cam profile that is rigidly coupled to the inlet of the main body, against which a diametrical stem of the knob engages that is adapted to cause the axial sliding of the end of the cylinder to move the shafts into positions that are spaced from the stem and cause their disengagement.