Creates sharp points with little effort on your part. Best Manual:. An old-fashioned crank sharpener made of metal. Best for Classroom:. This heavy-duty electric pencil sharpener plugs into an electrical outlet.
Best for Colored Pencils:. Designed to work with prism color pencils. Best for Artists:. Works perfectly on both charcoal and pastel pencils.
In This Article Expand. Our Picks. What to Look For. View On Amazon. The 8 Best Notebooks. The 14 Best Gifts for Teachers in The 7 Best Art Easels for Kids in What to Look for When Buying Pencil Sharpeners Manual or Electric To find the pencil sharpener that best suits your needs, first decide whether you prefer a manual or electric device.
Pencil Diameter While most of us think of standard school-issued No. Built-In Reservoir If you are a casual pencil user looking for an inexpensive simple tool to sharpen your No. How do you sharpen a pencil sharpener blade? How does an electric pencil sharpener work? Who invented the pencil sharpener? The 8 Best Pencil Erasers. Continue to 5 of 7 below. Your Privacy Rights. Pencils get dull while they are used and its core shortens, so a pencil sharpener shaves the casing and the core of the wooden pencil until it shapes the point.
It can be operated manually or by an electric motor. Before pencil sharpeners appeared, pencils were sharpened with small knives or with sand paper.
In , French mathematician Bernard Lassimonne patented the first pencil sharpener. Next improvement came from the other side of the Atlantic in , from a man called Walter K.
These inventions had only one flaw. They all demanded user to hold the sharpener steady and turn the pencil or vice versa which often broke the lead. 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.
These mechanisms are also called planetary sharpeners , 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 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 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, but most have two cylinders or more. Most planetary sharpeners have a large opening, with a rotatable guide disk in front of it that has multiple holes of different sizes, to accommodate pencils of many different diameters.
Advanced models have a spring-driven holder for the pencil, so that the pencil automatically is pushed into the mechanism while being sharpened. Some versions also offer a regulator of the desired sharpness, since it is not always desired to make the graphite core needle-sharp. Some older models like the German Jupiter 1 used reversible rotary cutter-disks with cutting edges radiating from the center on each side. These were high-end models, quite large and expensive.
Others simply used abrasives like sandpaper. In some cases an abrasive was used to shape the graphite core, while the wood was cut some other way. Electric pencil sharpeners were introduced by They work on the same principle as manual ones, but one or more flat-bladed or cylindrical cutters are rotated by an electric motor.
The wedge mechanism is highly portable and versatile. You can carry a tiny bladed sharpener with you wherever you go, and you can find a wide variety of novelty sharpeners in all sorts of designs that use this hand-cranked design.
Have we piqued your interest? Shop our pencil sharpeners. We keep a rotary sharpener in our house to this day. What is the economic impact of the pencil sharpener? That is, how many are made each year and how many people are involved in making the pencil sharpener.
0コメント