It’s true. This pencil applied for a utility model patent in 2004 and obtained the utility model patent authorization in 2005. The following is part of the patent information:
Square lead mechanical pencil
Application number: 200420081948.6 Application date: 2004-08-16
Abstract: The utility model discloses a square lead mechanical pencil that is suitable for filling in answer sheets and can continuously take out the core. , it includes inner rod, connector, inner rod seat, chuck, locking ring, etc. The inner rod and chuck are respectively equipped with square lower core holes. The inner rod and the connector, the connector and the chuck are respectively oriented and sleeved so that Their square lower core holes are aligned, and the inner rod is also equipped with a rectangular core storage hole. The rectangular width of the core storage hole is equivalent to the thickness or width of the square lead core. The rectangular length of the core storage hole is equal to the sum of the widths of several square lead cores. Or the total thickness is equal, and the left and right inner walls of the inner rod are respectively provided with lower core slopes corresponding to each square lead core at different heights.
Applicant: Han Aiguo
Address: 325011 Tianjiao Pen Company, Community 26, Wenzhou Economic and Technological Development Zone, Wenzhou City, Zhejiang Province (Shangjiang)
Invention ( Designer: Han Aiguo
Main classification number: B43K21/04
Classification number: B43K21/04 B43K19/18