View source for Engineering:Pencil sharpener

{{Short description|Tool for sharpening a pencil's writing point by shaving away its worn surface}}
[[File:Sharpener with Pencil.jpg|thumb|A manual prism sharpener generates long fan-shaped shavings.]]
[[File:Apsco Vacuhold pencil sharpener 15.ogv|thumb|Video of a mechanical pencil sharpener, showing gearing and helical sharpening blades]]
[[File:Aerra's Films of the Ordinary I -- Staedtler Pencil Sharpener.webm|thumb|Video showing a manual prism sharpener]]
A '''pencil sharpener''' (or '''pencil pointer''', or in Ireland a '''parer''' or '''topper'''<ref name="CoughlanHughes2007">{{cite book|author1=Gerry Coughlan|author2=Martin Hughes|title=Irish Language and Culture|url=https://books.google.com/books?id=bhfHeSgnAcQC|year=2007|publisher=Lonely Planet|isbn=978-1-74059-577-3|page=74}}</ref>) is a tool for sharpening a [[Engineering:Pencil|pencil]]'s writing point by shaving away its worn surface. Pencil sharpeners may be operated manually or by an [[Physics:Electric motor|electric motor]]. It is common for many sharpeners to have a casing around them which can be removed for emptying the pencil shavings debris into a bin.

==History==
<!-- NOTE TO EDITORS: The French word *crayon* refers to what is called a *pencil* in English. Do not let this cause confusion! -->
Before the development of dedicated pencil sharpeners, a pencil was sharpened by whittling with a [[Engineering:Penknife|knife]].

The development of pencil sharpeners began in France when a French book from 1822 reported in detail about an invention of Mr. C. A. Boucher (Paris) for the construction of a pencil sharpener. He was working with [[Engineering:Pantograph|pantograph]]s and apparently needed a device to precisely sharpen the pencils.<ref>{{Cite book|url=https://books.google.com/books?id=Vut7Bt4AjmIC&q=boucher+taille+crayon&pg=PA290|title=Recueil de la Société polytechnique: ou Recueil industriel, manufacturier, agricole et commercial, de la salubrité publique, ...|date=1822|publisher=Société polytechnique|pages=290–295|language=fr}}</ref><ref name="Grahl">{{Cite web|url=http://patent-infos.de/overview/history-pencil-sharpeners-1850.html|title=History of pencil sharpeners and pointers −1850 Lassimone, Cooper/Eckstein, Lahausse|last=Grahl|first=André|website=patent-infos.de|access-date=2019-03-01|archive-url=https://web.archive.org/web/20191113171647/http://patent-infos.de/overview/history-pencil-sharpeners-1850.html|archive-date=13 November 2019|url-status=dead}}</ref> The device of Mr. Boucher was technically sensible and functional. His idea was also internationally known and recognized, as shown by corresponding reports in German literature at this time.<ref>{{Cite book|url=https://books.google.com/books?id=Vm9QAAAAcAAJ&q=boucher|title=Allgemeine Maschinen-Encyclopädie: A – Beu|last=Hülsse|first=Julius A.|date=1841|publisher=Voss|pages=247|language=de}}</ref> But Mr. Boucher had not applied a patent for his pencil sharpener. Commercial use of his inventions is unlikely.

French mathematician Bernard Lassimonne (Limoges) applied for the world's first patent (French patent #2444) on a pencil sharpener in 1828.<ref>{{Cite book|url=https://books.google.com/books?id=BkYFAAAAQAAJ&q=lassimonne+taille+crayon&pg=PA383|title=Description des machines et procédés spécifiés dans les brevets d'invention, publ. par C.P. Molard. [With] Table générale des vingt premiers volumes...|date=1835|pages=583, 81–83|language=fr|last1=Du Commerce|first1=France min}}</ref> Pencil sharpener devices using his patent were actually produced and sold by Binant, a shop for painting accessories in Paris.<ref name="Grahl" /> In 1833 in England, Cooper & Eckstein patented the so-called Styloxynon, a simple device consisting of two sharp files set together at right angle in a small block of rosewood.<ref>{{Cite book|url=https://books.google.com/books?id=esA-AAAAcAAJ&q=cooper+eckstein&pg=PA318|title=Repertory of patent inventions and other discoveries and improvements in arts, manufactures and agriculture|date=1833|publisher=Macintosh|pages=318–319|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=qoqJvkEyCnIC&q=185|title=The Mechanics' Magazine, Museum, Register, Journal & Gazette|date=1837|publisher=Knight and Lacey|pages=185|language=en}}</ref> This is the oldest pencil sharpener that has surviving examples.<ref>{{Cite web|url=https://www.worthpoint.com/worthopedia/antique-early-patent-pencil-sharpener-633650095|title=RARE ANTIQUE EARLY PATENT PENCIL SHARPENER 1830s – COOPER & ECKSTEIN STYLOXYNON|website=Worthpoint|language=en|access-date=2019-03-01|archive-url=https://web.archive.org/web/20190302024601/https://www.worthpoint.com/worthopedia/antique-early-patent-pencil-sharpener-633650095|archive-date=2 March 2019|url-status=dead}}</ref>

In the 1830s and 1840s, some French people, all based in Paris, were engaged in construction of simple pencil sharpening tools, like François Joseph Lahausse.<ref>{{Cite book|url=https://books.google.com/books?id=Cf7NAAAAMAAJ&q=lahausse+taille+crayon&pg=PA406|title=Bulletin de la Société d'encouragement pour l'industrie nationale|date=1834|publisher=Société d'encouragement pour l'industrie nationale|pages=406–407|language=fr}}</ref> These devices were partially sold, but without supra-regional significance. In 1847, the French nobleman [http://www.rupertwilloughby.co.uk/gleanings/constant-de-thierry-des-estivaux-marquis-de-faletans-inventeur-du-taille-crayon Thierry des Estivaux] invented a simple hand-held pencil sharpener in its recognizable modern form.<ref>{{Cite book|url=https://books.google.com/books?id=hEky1B7Fl0sC&q=estiveaux+taille+crayon&pg=PA260|title=Description des machines et procédés pour lesquels des brevets d'invention ont été pris sous le régime ...|date=1852|publisher=L'Imprimerie Nationale|pages=260|isbn=9781010644743|language=fr}}</ref><ref>{{citation |magazine=Discover magazine |date=May 2007 |url=http://discovermagazine.com/2007/may/20-things-you-didnt-know-about-pencils |title=20 Things You Didn't Know About... Pencils |access-date=2009-04-30 |archive-date=21 April 2009 |archive-url=https://web.archive.org/web/20090421150616/http://discovermagazine.com/2007/may/20-things-you-didnt-know-about-pencils |url-status=live }}</ref> The first American pencil sharpener was patented by Walter Kittredge Foster of Bangor, Maine in 1855.<ref name="officemuseumsmall">{{cite web|url=http://www.officemuseum.com/sharpener_small.htm|title=Handheld Pencil Sharpeners|access-date=9 July 2011|archive-url=https://web.archive.org/web/20110718121544/http://www.officemuseum.com/sharpener_small.htm|archive-date=18 July 2011|url-status=dead}}</ref> He founded a company – the first pencil sharpener company in the world – and produced such small hand-held pencil sharpeners in a large amount. Only a few years later the sharpeners were sold also in Europe as "American pencil sharpeners".<ref>{{Cite book|url=https://books.google.com/books?id=NdJFAAAAcAAJ&q=amerikanische+bleistiftspitzer&pg=PT1613|title=Neueste Nachrichten aus dem Gebiete der Politik: 1858|date=1858|publisher=Wolf|pages=2623|language=de}}</ref>

At the end of the 19th century, especially in the United States, pencil sharpeners with various mechanisms had been developed and put on the market. These devices were often heavy and intended for use in schools and universities. Examples are the Perfect Pencil Pointer (Goodell. Co.), the GEM Pencil Sharpener (by Gould & Cook Co.), the Planetary Pencil Sharpener ([[Company:A. B. Dick Company|A. B. Dick Company]]), all from the US or the Jupiter (Guhl & Harbeck Co.) from Germany.<ref name=":0">{{Cite web|url=https://www.officemuseum.com/sharpener_gallery_1900-1909.htm|title=Mechanical Pencil Sharpeners ~ 1900–1909|website=officemuseum.com|access-date=2019-03-03|archive-date=14 March 2019|archive-url=https://web.archive.org/web/20190314014742/http://www.officemuseum.com/sharpener_gallery_1900-1909.htm|url-status=live}}</ref> At the beginning of the 20th century the company Automatic Pencil Sharpener Co. (APSCO) was founded and brought out the US Automatic Pencil Sharpener after 1907,<ref name=":0" /> which dominated in those years. They later sold machines with milling mechanisms, such as the Climax, Dexter, Wizard, and Junior models.<ref>{{Cite web|url=https://www.officemuseum.com/sharpener_gallery_1910-1919.htm|title=Mechanical Pencil Sharpeners ~ 1910–1919|website=officemuseum.com|access-date=2019-03-03|archive-date=28 February 2019|archive-url=https://web.archive.org/web/20190228201905/http://www.officemuseum.com/sharpener_gallery_1910-1919.htm|url-status=live}}</ref> In the next few decades, APSCO became the largest pencil sharpening machine producer in the world and together with a few other US companies, it dominated the market.

Electric pencil sharpeners for offices have been made since at least 1917.<ref name="officemuseumelectric" />

In May 2011, tourism officials in Logan, Ohio, put on display, in its regional welcome center, hundreds of pencil sharpeners which had been collected by Rev. Paul Johnson, an Ohio minister who died in 2010. Johnson, a World War II veteran, had kept his collection of more than 3,400 sharpeners in a small shed, outside his home in Carbon Hill in southeast Ohio. He had started collecting after his wife gave him a few pencil sharpeners as a gift in the late 1980s and kept them organized into categories, including cats, Christmas, and Disneyland.<ref>{{Cite web |title=New home for Ohio man's pencil sharpener 'museum' |url=https://abc7.com/archive/8135635/ |website=ABC7 Los Angeles |language=en |access-date=24 February 2024 |archive-date=24 February 2024 |archive-url=https://web.archive.org/web/20240224123411/https://abc7.com/archive/8135635/ |url-status=live }}</ref>

==Manual==

=== Prism ===
{{original research|section|date=October 2024}}
[[File:KUM Sharpener.jpg|thumb|left|[[Magnesium alloy]] prism sharpener]]
So-called "prism" sharpeners, also called "manual" or "pocket" sharpeners in the United States, have no separate moving parts and are typically the smallest and cheapest commonly used pencil sharpener on the market. The simplest common variety is a small rectangular [[Prism (geometry)|prism]] or block, only about 1 × 5/8 × 7/16&nbsp;inch (2.5 × 1.7 × 1.1&nbsp;cm) in size. The block-shaped sharpener consists of a combined point-shaping cone that is aligned to the cylindrical pencil alignment guide hole, into which the pencil is inserted. A sharp blade is mounted so that its sharp edge just enters the shaping cone [[Tangent|tangent]]ially. The pencil is inserted into the sharpener and rotated while the sharpener is held motionless. The body of the sharpener is often contoured, ridged or grooved to make the small block easier to firmly grip, and is typically made of aluminum alloy, [[Chemistry:Magnesium alloy|magnesium alloy]] or hard [[Chemistry:Plastic|plastic]].

[[File:Taille crayon mécanique-h.jpg|thumb|An unusual hand-cranked prism sharpener, with a shavings cover]]
The blade inside the sharpener shaves the wood and graphite tip of the pencil, while the shavings emerge through a slot along the blade edge. It is important that the cylindrical alignment hole closely fits the diameter of the pencil, to keep the pencil from wobbling, which would cause stepped or lurching cut-depths and point breakage. Another important feature is a larger clearance hole at the end of the cone allowing sections of the pencil lead which break away to be removed with only minor inconvenience. Prism sharpeners can be bare or enclosed in a container to collect the shavings, while some enclosed sharpeners may be harder to clear in the event of a blockage.

A few prism sharpeners are hand-cranked, rotating the cutting blade instead of rotating the pencil. Moderate care is needed to not break the tip of the pencil being sharpened, requiring the pencil to be sharpened again. However, because pencils may have different standard diameters in different nations, imported sharpeners may have non-standard-sized alignment guide-holes, making sharpening attempts difficult. If the alignment hole is too small, the pencil cannot be inserted, while if it is too large, the tip of the pencil will repeatedly break off. Prism sharpeners may be right- or left-handed, requiring clockwise or counter-clockwise rotation of the pencil being sharpened.

=== Linear blade ===
[[File:Temperowka.na.zyletke.jpg|thumb|A linear sharpener that uses a [[razor|razor blade]]]]
Unlike prism sharpeners, linear blade sharpeners do not rotate relative to the pencil being sharpened, and may be viewed as just a special form of knife, with a mechanical guide for increased safety and convenience. Some models use replaceable shaving razor blades, while others have permanently-fitted blades. Linear blade sharpeners may require more skill, but they allow one to sharpen the tip of the pencil into any desired shape and angle of taper, whereas prism sharpeners have a fixed sharpening angle and produce circular symmetry.

While most linear blade sharpeners are simple and directly hand-operated, some devices in the past were crank-operated, using mechanisms to convert crank rotation into linear motion.<ref name="officemuseum">{{cite web|url=http://www.officemuseum.com/pencil_sharpeners.htm|title=Pencil Sharpeners|access-date=9 July 2011|archive-date=25 July 2005|archive-url=https://web.archive.org/web/20050725080605/http://www.officemuseum.com/pencil_sharpeners.htm|url-status=live}}</ref>

=== Cylindrical (planetary) ===
These mechanisms are also called '''planetary sharpeners''',<ref name="officemuseum" /> in reference to their use of planetary gears. A larger, stationary planetary sharpener can be mounted on a desk or wall and powered by a hand [[Engineering:Crank (mechanism)|crank]]. Typically, the pencil is inserted into the sharpener with one hand, and the crank is turned with the other. This rotates a set of [[Helix|helical]] cylindrical cutters in the mechanism, set at an acute angle to each other. The multiple cutting edges quickly sharpen the pencil, with a more precise finish than a single-blade device . Some cylindrical sharpeners have only one helical cutter cylinder{{Citation needed|date=March 2018} ore.


=== Other systems ===
[[File:BleistiftschärfMaschineJupiter1.JPG|thumb|Jupiter 1 with rotary disk cutters]]

==Electric==
[[File:ELM V6 electric pencil sharpener.jpg|thumb|right|A well-used modern desk-style electric pencil sharpener]]
The oldest surviving electric pencil sharpener is the Boston Polar Club pencil sharpener, introduced around 1936.<ref>{{Cite web|url=https://www.antikeychop.com/bostonpolarclubpencilsharpener|title=The Antikey Chop|website=Boston Polar Club Pencil Sharpener|access-date=2019-08-28|archive-date=28 August 2019|archive-url=https://web.archive.org/web/20190828195410/https://www.antikeychop.com/bostonpolarclubpencilsharpener|url-status=live}}</ref> Electric pencil sharpeners work on the same principle as manual ones, but one or more flat-bladed or cylindrical cutters are rotated by an [[Physics:Electric motor|electric motor]].<ref name="officemuseumelectric">{{cite web|url=http://www.officemuseum.com/electric_sharpener_gallery.htm|title=Electric Pencil Sharpeners|access-date=9 July 2011|archive-date=10 November 2017|archive-url=https://web.archive.org/web/20171110214918/http://www.officemuseum.com/electric_sharpener_gallery.htm|url-status=live}}</ref> Some electric pencil sharpeners are powered by [[Physics:Battery (electricity)|batteries]] rather than being plugged into a building's electrical system, making them more portable.

Auto-stop electric pencil sharpeners are able to sense when the tip of the pencil is long enough, so they stop automatically. In basic automatic pencil sharpeners, the lead may become too long and break, and so users must be careful to supervise the operation.

== Specialized ==
[[File:Faber-Castell TK lead sharpener and 2 mm pencil lead.jpg|thumb|Lead sharpener/lead pointer and 2 mm pencil lead in a leadholder]]
[[File:Flat pencil sharpener.jpg|thumb|Specialized sharpener for carpenter's flat pencils]]
Specialized sharpeners are available that operate on non-standard sizes of pencil-shaped markers, such as wax crayons used in primary schools. Sharpeners that have two openings, one for normal pencils and one for larger crayons, are fairly common. Sharpeners with a single blade for use on wax crayons are available, and sometimes included in boxes of crayons. These often have plastic blades, which are adequate for the soft wax.

An artist's or draftsman's pencil sharpener leaves the graphite untouched and sharpens only the wood (some models can switch from standard to wood-only by an adjustment). The graphite lead is then honed to a sharp point with a lead pointer, which sharpens only the lead without wood. Lead pointers are also used with mechanical leadholders, with thicker diameter leads like 2&nbsp;mm which have removable/refillable leads. Some sharpeners which function as a long point sharpener, have a second hole in which the blade sharpens the untouched graphite to a long, more precise point than would be otherwise possible using a single hole long point sharpener.

Carpenters may use [[Engineering:Carpenter pencil|carpenter pencil]]s, the flattened shape of which stops them from rolling away, while still providing a constant line width. These pencils were traditionally sharpened with tools conveniently to hand, such as a [[Engineering:Plane (tool)|plane]] or sandpaper. Rotating pencil sharpeners are now available for these pencils, in which a rotating plastic collar holds the pencil in position, although they then sharpen to the usual conical point as for a round pencil, abandoning some distinctive aspects of the carpenter's pencil. Alternatively, a special carpenter's pencil sharpener can be used, which has a sliding mechanism that leaves flat facets on the lead, in a manner similar to hand sharpening with a sharp knife.

[[Engineering:Mechanical pencil|Mechanical pencil]]s with thin diameter leads dispense the graphite lead progressively during use and thus do not require sharpening; such pencils are sometimes called "self-sharpening". A type of mechanical pencil has a rotating gear mechanism which rotates the lead slightly every time the lead is lifted off the paper, helping to maintain a consistent, sharp point. If a finer or broader line is needed, a separate mechanical pencil using a lead with a different diameter is required.

==Gallery==
<gallery heights="160" widths="180">
File:CrankPencilShapener.jpg|Hand-cranked planetary sharpener, with cover in place
File:Apsco Vacuhold pencil sharpener 13.jpg|Hand-cranked planetary sharpener from 1950 to 1960, with cover removed
File:HighEndSharpener.png|Hand-cranked planetary sharpener with spring-driven pencil holder. The small knob behind the crank is a sharpness regulator.
File:SchoolPro Electric Pencil Sharpener.jpg|AC-powered electric pencil sharpener. The mechanism is similar to the planetary sharpener, except there is a motor instead of a crank.
File:PencilSharpenerBatteryOp.jpg|Battery-operated sharpener
File:Pencil sharpener Schwan wood.jpg|[[Earth:Ecology|Ecologically]] manufactured pencil sharpener made of wood
File:Pencil sharpener mechanism.jpg|A wall-mounted planetary sharpener (casing removed to reveal the mechanism)
File:Sharpener.jpg|Prism sharpener with two holes for two sizes of pencils
File:1970s Swiss pencil sharpener Gedess.jpg|A Swiss Gedess sharpener where sharpening is accomplished by swirling hand rotation
</gallery>

==See also==
*[[Engineering:Mechanical pencil|Mechanical pencil]]
*[[Engineering:Pencil Sharpener Museum|Pencil Sharpener Museum]]

== References ==
{{Reflist|30em}}

==External links==
{{ccat}}
*[https://web.archive.org/web/20191113171647/http://patent-infos.de/overview/history-pencil-sharpeners-1850.html André Grahl: History of pencil sharpeners and pointers]
*[https://www.youtube.com/watch?v=5Uqaj0lp9lo Video of production of hand-held pencil sharpeners]

{{Pencils}}
{{Cutting and abrasive tools}}
{{Hand tools}}

{{DEFAULTSORT:Pencil Sharpener}}
[[Category:Office equipment]]
[[Category:Sharpening]]
[[Category:Mechanical hand tools]]
[[Category:Articles containing video clips]]

{{Sourceattribution|Pencil sharpener}}