Cord can refer to an electrical cable that is thin, pliable, and insulated, or a thin rope or robust string. A lock is a mechanism to hold something in position, secure something, or keep something from moving. A cord lock is a device to hold a cord in a set position. While in some cases a cord lock is a generic product, in other cases it can be a proprietary, trademarked solution.
The cord is threaded through the product, which has two positions: one in which the cord moves freely and one in which the cord is locked in place by the cord lock mechanism, with the position generally being changed by a squeezing motion. A cord lock may also be referred to as a cordlock, a cord fastener, a cord stopper, a cord toggle, or a plastic stopper, and may be used in a number of different applications.
One typical shape for cord locks is a small, open-topped barrel shape with a traverse hole. A plunger shaped piece, also with a transverse hole is inserted in the top. In the closed position, the holes on the barrel and plunger are aligned and the cord moves through freely in either direction. When the plunger is open, it is locked; it shifts vertically with regard to the barrel such that the transverse holes are no longer aligned and the string is locked in place.
One use of the cord lock is in luggage and backpacks. Many backpacks have a top flap, and under that flap is a section that is shaped like a large grocery bag with a drawstring running through a hemmed section at the top. When the drawstring is tightened, the cord lock is used to keep it in place and the flap is secured over the top, adding double security to prevent losing any of the contents. Another use is to secure the tops of utility bags, such as sleeping bag covers, laundry bags for dirty clothes, and mesh bags for washing delicate items. Securing window treatments, such as window blinds, is another application.
Cord locks are also used in clothing, for example, on a drawstring at the waist of casual pants, but more often to seal out the wind and weather in outerwear and cold weather gear. Cord locks can be found, for example, around the edge of the hood on hooded sweatshirts. They are also used on the bottom hem of winter jackets and on the bottom hem of gloves and mittens.