Mechanical pencil

A mechanical pencil or pen refill (rarely also mechanical pencil ) is used instead of the regular ablated by sharpening wood mantle for the write mine a reusable sheath of plastic or metal. Unlike pencils and colored pencils with wood mantle, the handling remains constant at any mine length.

History

The earliest surviving example of a mechanical pencil was found in the wreckage of the sunken HMS Pandora 1791. Sampson Mordan and 1822 were John Isaac Hawkins in the UK, the first patent for a refillable pencil. After Hawkins bought out, Mordan sales 1823-1837 the pencil along with his partner Gabriel Riddle under the brand " SMGR ". After the end of the partnership Mordan produced the pencils under the name " S.MORDAN & CO. " This company produced until the Second World War, when the factory was destroyed by a bomb attack.

A total of 1822 and 1874 more than 160 patents have been issued on a number of different improvements of mechanical pencils between. In 1877 the first pin was patented spring device, a rotary mechanism was developed in 1895.

1915 brought Tokuji Hayakawa in Japan a mechanical pencil under the name Ever -Ready Sharp Pencil on the market, which was based on a screw. However, the success came only after a company from Yokohama gave a bulk order. The pen was the manufacturer later its name: Sharp.

The immediate predecessor of today's most widespread variant ( with clamping pliers), however, was an invention of the American Charles Rood Keeran. He applied for a patent in 1913 on its development of registry in 1915. Keerans From this point pens were sold under the brand name Eversharp.

Today's form

Today probably most common form of a mechanical pencil refills used with a thickness of 0.2 mm to 1.18 mm, which are held by a clamp pliers in a guide. By slightly opening the clamping pliers by means of the push button on the pin header or on the side surface of the lead is a few millimeters advanced. The coat of the pen more mines may be stored. The guide may be rigidly mounted or suspension, depending on the application in technical or rarely also in the artistic field. The usual length of the mines is 60 mm.

PENCIL

The mechanical pencil is like the mechanical pencil, but uses ordinary pencil lead. These have a special sharpener ( sharpener, also Dahle, Spitzmühle, Gedess ) are tipped, which is unpleasant by the resulting coloring graphite dust for the fingers. Gern is also used a piece of sandpaper, which is just like that, or glued used on a wood plate. The name PENCIL explained by its function: When you press the button above, opens below the clip, and the mine falls out. The mines are mostly 2 mm thick and so much more stable than the thinner mines of mechanical pencils. A typical clutch pencil contains reasons of space, only one mine, which is about as long as a regular pencil lead.

Mechanical pencils were widespread in the 1970s and 1980s, today there are mechanical pencils more often. However, there are areas in which the mechanical pencils are unsuitable, and where the clutch pencil continues to be used. So, for example, use Graphic designer, artist or architect the clutch pencil for free drawing and sketching. Here mechanical pencils are useless. Mechanical pencils are available for mines in up to 6 mm thickness and in all degrees of hardness.

Other variants

• The mechanical pencil reaches the feed of the mine by a rotating mechanism of the pen rather than by means of the push button.
• There are multi-function devices, especially combinations of mechanical pencil and ballpoint pen.
• Some mechanical pencils or mechanical pencils have a built-in eraser on the top end, which often serves as a cover for the lead stock.