Electrical grinding machine for coffee beans

A grinding machine for coffee beans comprising a casing, a grinding chamber in said casing, a rotary mill body in said grinding chamber, an electric motor disposed in said casing and coupled to said rotary mill body for driving said rotary body in rotation, a non-rotatable mill body in said grinding chamber opposed to said rotary mill body, said mill bodies including ridges thereon facing one another, said non-rotatable body being supported for longitudinal displacement in said casing, said mill bodies being annular and defining an interior chamber, one of said bodies having an inlet opening for admission of coffee beans to be ground into said interior chamber, a supply chamber in said casing for coffee beans, means establishing communication between said supply chamber and said interior chamber, means for displacing said non-rotatable mill body for advancement and retraction with respect to said rotary mill body to adjust the spacing therebetween, an adjustment member including a rotatable knob external of said casing coupled to said means for displacing the non-rotatable mill body to adjust the position of said non-rotatable mill body with respect to said rotary mill body, and a receiving container removably coupled to said casing and having an inlet facing an outlet provided in said grinding chamber to receive ground coffee from said mill bodies, said means for displacing said non-rotatable mill body comprising a rotatable threaded member threadably engaged with said non-rotatable mill body, an operation shaft coupled to said knob, gear means coupling said threaded member and said operation shaft, and restraining means acting on said adjustment member for establishing index positions therefore for holding the non-rotatable mill body in adjusted spaced position relative to the rotary mill body, said threaded member and operation shaft extending perpendicularly to one another, said gear means comprising bevel gears respectively on said operation member and said threaded member and in mesh with one another.