Bean and nut grinder shift mechanism

Abstract

A grinder refinement mechanism for use with a conventional coffee or peanut grinder is disclosed. The grinder includes the usual screw conveyor having a rotary grinding burr attached to a forward end thereof, a stationary grinding burr connected to a wall of the grinder housing and a main spring which biases the screw conveyor toward the forward end of the grinder housing against an adjustment screw projecting through an end wall. The mechanism includes a lever arm pivotally attached to an outside surface of the end wall and an electrical solenoid connected to the arm. The usual adjustment screw is replaced with a plunger element which slidably projects both into and out of the end wall and is confined between a forward end of the screw conveyor and the arm. In one condition of the solenoid, the main spring forces the screw conveyor and plunger forwardly to hold the arm against a stop screw which thus determines the desired coarse grinding condition of the grinder burrs. In the other condition of the solenoid, the arm is drawn off the stop screw to force the plunger and screw conveyor rearwardly in opposition to the main spring to a fine grinding condition of the grinder burrs. The coarse and fine grinding conditions of the grinder burrs can be precisely adjusted by the stop screw and a screw mounted on the arm which bears on the plunger. Additional solenoids may be employed in different arrangements to obtain more than two grinding conditions such as coarse, intermediate and fine grinding conditions. A relief spring connected between each of the solenoids and the arm permit the arm to flex momentarily when the grinder encounters binding or jamming to relieve such conditions.