Washing Machine, Household

a machine for soaking, washing, rinsing, blueing, and extracting water from clothes. The first washing machine was introduced in the USA in the 1880’s.

The major components of a washing machine are the agitator (a disk with fins), impeller, or drum; a wringer; a pump; one or several electric motors for driving these units; and the wash tub. Washing machines may be small, portable models without wringers, models with manual roller wringers, semiautomatic twin-tub models with spin dryers for extracting water from the clothes, semiautomatic, single-tub, drum-type models, and fully automatic models. Some automatic, combination-type washer-dryers have a heating element in the cover for drying the clothes. Other automatic models use jets of water for washing; the clothes are placed on hangers, washed, rinsed, dried, and smoothed by hanging.

Small washing machines with manual roller wringers and semiautomatic twin-tub models include those models having a wash tub mounted on a vertical axis and an agitator installed on the bottom or side. The used wash water is emptied by spontaneous flow or by means of a pump, and the required washing time is regulated by an electric timer. In twin-tub semiautomatic machines, one tub is used for washing and rinsing, and the other is used for extracting water.

In drum-type washing machines, the washing action takes place in a perforated drum that rotates inside the wash tub on a horizontal axis. In automatic machines, which are mainly of the drum type, the filling of the tub with water, soaking, washing, emptying of the wash water, rinsing, and extraction take place without attention by the operator.

The power requirements of washing machines vary from 200 to 800 watts, and the nominal load varies from 1 to 5 kg of clothes. (SeeMUNICIPAL MAINTENANCE MACHINERY for a discussion of commercial washing machines.)