Sharpening device for pencil leads

Claim 1

IN A SHARPENING DEVICE OF THE CHARACTER DESCRIBED: A LOWER HOUSING ADAPTED TO REST UPON A DRAWING BORD, A MOTOR MOUNTED IN SAID HOUSING WITH ITS SHAFT EXTENDING SUBSTANTIALLY VERTICALLY THROUGH THE TOP WALL THEREOF, AN UPPER HOUSING POSITIONED ON THE TOP WALL OF SAID LOWER HOUSING AND FORMING THEREWITH AN ENCLOSED CUTTER CHAMBER, MANUALLY RELEASABLE MEANS NORMALLY SECURING SAID UPPER TO SAID LOWER HOUSING, DOWEL MEANS IN SAID HOUSINGS, FOR THE ACCURATELY ALIGNED INTERENGAGEMENT OF SAID HOUSINGS, AND A CUTTER ASSEMBLY LOCATED IN SAID ENCLOSED CUTTER CHAMBER, SAID CUTTER ASSEMBLY INCLUDING A BLADE SUPPORT SECURED DIRECTLY TO THE UPPER END OF SAID MOTOR SHAFT AND A PLURALITY OF INDEPENDENT CUTTER BLADES EACH SECURED AT ONE END IN FIXED RELATION TO SAID SUPPORT, EACH OF SAID CUTTER BLADES BEING FORMED WITH A CONCAVE CUTTING EDGE EXTENDING IN A GENERALLY AXIAL DIRECTION RELATIVE TO SAID SHAFT, AND SAID UPPER HOUSING HAVING AN ELONGATED CANT-PREVENTING GUIDE PASSAGE IN THE TOP WALL THEREOF AXIALLY ALIGNED WITH SAID SHAFT FOR RECEIVING AND SUPPORTING THE BODY OF A DRAFTING PENCIL, SAID GUIDE PASSAGE TERMINATING IN A SMALLER AXIALLY ALIGNED PENCIL-LEAD CENTERING PASSAGE OPENING INTO SAID CUTTER CHAMBER, WHEREBY SAID UPPER HOUSING IS REMOVABLE FOR CLEANING AND CLEARING BROKEN LEADS FROM SAID BLADES.