Binder clip
From Wikipedia, the free encyclopedia
A binder clip is a simple device for binding pieces of paper. A binder clip is a strip of sheet steel bent into the shape of an isosceles triangle with loops at the apex. Tension along the base of the triangle forces the two sides closed, and the loops prevent the sharp steel edges from cutting into the paper. The loops also serve to hold two pieces of stiff wire, which serve as handles and allow the clip to be opened. The two slots cut in each loop are cleverly shaped so that the wire handles can be folded down once the clip has been attached, and the spring force of the wire holds them down on the surface of the paper. This holds the clip relatively flat, for easier stacking (see upper right corner of the photo). The handles can also be removed altogether by squeezing them sideways and pulling them out.
There are two sizes of binder clips that are common in the modern office. A small clip measures 9 mm at the base and 38 mm with the U clips flipped in line with the apex. A medium clip has a base of 15 mm and is 56 mm tall. The sheet steel portion is customarily painted black, with the handles chrome plated (as shown in the photo), but a variety of decorative color schemes are also available.
The binder clip has replaced the use of the paperclip for large volumes of paper (e.g. documents of 25 or more pages.)
The term bulldog clip is used in the United Kingdom to describe both this invention and an older device with the same function, which has rigid rather than folding handles.
