Sharpener Technical Description

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Running Head: SHARPENER ANALYSIS
Technical Description of a Standard Prism Sharpener
and its Components
David Jimenez
City College of New York
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The first ever pencil sharpener to be patented was by French mathematician Bernard
Lassimonne in 1828 (Prism). Before the pencil sharpener became standard, pencils were
sharpened manually using a knife (2016). There are several different types of sharpeners
including prism sharpeners, linear sharpeners, cylindrical sharpeners and electrical sharpeners.
This description will focus on the prism model sharpener. The prism model is probably the
simplest as it contains no moving parts. It is composed of a blade made of a sharp plastic or
metal alloy, and a fitting compartment for a pencil tip to be inserted. It functions by continuously
carving the edge of the pencil into a molded point as the user rotates the pencil while the
sharpener remains stationary or vice versa. Most modern prism sharpeners also have a detachable
compartment which hold the shavings of the pencil. They are also very small and hence they are
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smaller height and width as this is where the very point of the pencil will reach. The holes in the
sharpener must tightly conform to the pencils shape or the point will be broken easily due to
wobbling. As a result, the base of the sharpener gets smaller from the back to the front as it is
conforming to the shape of the pencil from the base to the point.
The standard size of a blade for a pencil sharpener is 4.064×3.302×1.016 cm. The blades
of a sharpener will be securely fastened to the top of the sharpener’s structure using a screw
which go directly through the middle of the blades. The blades also weigh 9.072 grams and are
standardly forged of tempered steel. This allows for long continued use without the sharpener
dulling. However, one may choose to sharpen them
rather easily if they remove the blade by unscrewing it
from the structure which it is fastened to. Branding may
be etched into the top side of the blade as well.
Lastly, like most cutting utensils, the blade is only
sharpened on one side as you only need one to carve the
pencil’s tip.
The structure of the prism sharpener is it’s most defining feature as its architecture is vital
to its functionality. A standard prism sharpener size is 2.5×1.7×1.1 cm in size. They also tend to
weigh no more than 40-50 grams. This allows for its extreme portability as opposed to its
functional counterparts. However, the most important aspect of the prism sharpener’s
functionality is the conal holes which the pencil tip is inserted into. The conal holes are designed
with the intent to wrap around the pencil tip very tightly so that the pencil tip does not have
much room to move or wobble resulting in a sharp and sturdy finish with no breakage. Also,
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these conal holes are designed so that the pencil comes in contact with the blades tangentially.
This design allows for the pencil to be sharpened very easily with a rotational motion. Taking
into account the hexagoganol edge design of a pencil, the diameter of a pencil is around 7mm
standardly, so the conal base will be around this diameter or very slightly larger.
The shavings cover of a prism sharpener is not necessarily one of its defining features,
rather it is a supplementary one. This compartment may be of various different sizes, shapes, and
colors, however, it is most commonly made out of plastic.
Prism sharpeners with a shavings cover are designed with
a particular architecture in which the shavings cover may
be attached to the sharpeners structure so that it may be
easily attached and detached. The two components are
designed so that their attaching ends are roughly the same
size when fixed together, so that the plastic is forced to
flex a bit to fit. As a result a secure attachment is created which can be easily detached when
necessary. The shavings cover as a whole enhances the portability aspect of the sharpener as it
allows one to sharpen while away from a disposal bin.
Lastly the standard screws in a sharpener are cross recessed pan head screws. These
screws standardly have a philips driver type and a plain finish for ease of use. The screws also
have anti-corrosive properties. These screws attach the blades to the structure of the sharpener
allowing them to be removed if one pleases to perform maintenance on the blades.
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References
The Prism Sharpener. (2016, July 27). Retrieved November 2, 2018, from
https://theinspirationshots.com/2016/07/28/the-prism-sharpener/

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