First paragraph of US patent 1373062.
Today marks the 100th anniversary of a very important part of the famed Eberhard Faber Blackwing pencil: the patent for the pencil’s distinctive ferrule and eraser, originally called a clamp. (The name changed over time.)
The clamp patent was awarded to Lothar W. Faber on this day one century ago. The mechanism was shared with the Van Dyke and Microtomic pencils, mechanical pencils, and stand alone erasers. The Blackwing itself was launched a decade later. The clamp did have predecessors, but the 1921 patent was the most successful and widely known model.
The Eberhard Faber Pencil Company clearly took pride in the invention, noting the patent date on the box of Item 1281, their four eraser plus one clamp refill kit:
Also on some versions of the clamp itself:
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