A pencil sharpener is a tool that makes pencil sharpening easier. There are various designs of pencil sharpeners - from hand held in a pocket or pencil case, to larger sharpeners mounted on a table in the office (mechanical and electrical). The latter always have a compartment for collecting chips (available in some pocket sharpeners). Sharpeners use the translational or rotational movement of the cutter relative to the pencil.
History
Before developing a special pencil sharpener, the pencil was sharpened with a knife . Pencil sharpeners made this task much easier and gave a more even sharpening of the pencil. Some specialized types of pencils, such as carpentry pencils , are usually sharpened with a knife, due to their flat shape.
Bernard Lassimon, a French mathematician, took the first patent (French patent No. 2444) for pencil sharpeners in 1828 [1] . The first American pencil sharpener was patented by Walter C. Foster from Bangor in 1855 [2] . Electric pencil sharpeners for offices were created in 1917 [3] .
Sharpeners currently have a wide range of colors and shapes.
See also
- Knife -sharpener for knives.
Notes
- ↑ " 20 Things You Didn't Know About ... Pencil, " Discover magazine , May 2007 , < http://discovermagazine.com/2007/may/20-things-you-didnt-know-about-pencils > . Retrieved January 18, 2011.
- ↑ Handheld Pencil Sharpeners
- ↑ See the photo on the Museum's Early Office website , which also shows early electric sharpeners used on an industrial scale.