The IMechE Archives have recently received a collection of patents that document a significant step in the history of the washing machine. They have been deposited with the institution by the family of Walter William Ralph Searle, an engineer who worked on the development of the Hoover Keymatic. They date to the early 1960s and include a patent for the timer control for automatic washing and drying, one of the most significant features of this model.
The washing machine is a great example of engineering having a hugely positive impact on everyday lives. Although keeping clothes clean has been of concern ever since people began wearing them, for thousands of years there was little technological assistance in this laborious task. For the relatively wealthy, the usual technique was to agitate the clothes in hot water and soap in large iron cauldrons, filled by hand. Those without such resources would wash clothes in rivers by pounding and rubbing them against rocks.
During the 18th century a few technological innovations came about: the copper, a large metal boiler; the dolly stick, which was used to agitate washing within the tub, forcing the soapy water through it; and the washboard, a corrugated board made from zinc-covered wood, against which clothes were rubbed to remove dirt. Although these were undoubted improvements, laundry was still an extremely time-consuming activity which was generally spread over the entire week, with one whole day given over to the physical act of washing.
The 19th century saw washing technology develop further. Many attempts were made at creating a washing machine but each was essentially a mechanical imitation of the traditional method of washing clothes with dolly stick and washboard. Most were wooden tubs or boxes which stood on metal stands. They were usually churned by hand, but some were rocked by means of a foot pedal. The tubs usually had corrugated sides with agitation supplied by dolly sticks attached to the lid or base, by paddles or by pegged rollers. They had to be filled and emptied manually, and the water usually had to be heated first, although by the end of the century some models were being produced which burned gas or coal to heat water in the tub.
The first electric machines appeared at the turn of the 20th century. Early models were produced by adding an electric motor to existing machines, but these turned out to be dangerous as many tubs leaked water into the motor, and there were cases of women being electrocuted. Eventually the wooden tubs were replaced with metal tubs in enamelled cabinets with waterproof motors. Water had to be heated separately and added to the tub. It was not until the 1950s that it was possible to heat the water electrically.
Electric washing machines were initially more popular in the US than in the UK, and consequently they were more technologically advanced than those produced in the UK. During the Second World War years, when rationing halted production, US washing machine companies concentrated on the development of automatic machines. They were able to launch the first automatic model in 1947.
In Britain, sales of electric washing machines did not take off until the 1950s. In the 1960s automatic machines began to appear and they soon became a huge success. The Keymatic was one of the earliest models, first appearing in 1961. It used an innovative notched plastic key which controlled the wash cycle when inserted into a slot in the machine.
Within 200 years, washing technology developed from virtually nothing to complex machines where the user had only to load and empty the machine, saving countless hours of drudgery.