Clay crushing machine

A machine for the crushing and sizing of mineral substances comprising in combination:

• (a) a first horizontal crushing rotor mounted for rotation about a first axis;
• (b) a second horizontal crushing rotor mounted for rotation about a second crushing axis that is parallel to the first axis;
• (c) means for rotating said rotors in synchronism;
• (d) a first continuous non-circular circumferential crushing surface on said first rotor,
• (e) a second continuous non-circular circumferential crushing surface on said second rotor,
• (f) said first and second crushing surfaces forming a first crushing stage of the machine and being arranged to lie face-to-face continuously as the rotors rotate;
• (g) said first and second rotors being spaced to rotate so as to define a crushing gap therebetween;
• (h) said first and second axes being fixed in position and said first and second crushing surfaces being non-circular and complimentary so that the width of said crushing gap set forth in (g) remains fixed as the rotors rotate;
• and
• (i) at least one perforated grid means located adjacent to the underside of at least one of the first and second rotors and forming therewith a sizing gap whose width varies as the rotors rotate from a maximum size which is greater than said fixed crushing gap to a minimum size which is less than said fixed crushing gap to thus ensure that the rotor and grid means form a second crushing stage for the machine.