Washing machine

[3] One of the first innovations in washing machine technology was the use of enclosed containers or basins that had grooves, fingers, or paddles to help with the scrubbing and rubbing of the clothes.

[5] In 1862, a patented "compound rotary washing machine, with rollers for wringing or mangling" by Richard Lansdale of Pendleton, Manchester, was shown at the 1862 London Exhibition.

[citation needed] Bendix Home Appliances, a subsidiary of Avco, introduced the first domestic automatic washing machine in 1937,[19] having applied for a patent in the same year.

At the appropriate time in the wash cycle, each cam actuates a switch to engage or disengage a particular part of the machinery (for example, the drain pump motor).

[23] On the early electromechanical timers, the motor ran at a constant speed throughout the wash cycle, although the user could truncate parts of the program by manually advancing the control dial.

With this arrangement, the electric timer motor is periodically switched off to permit the clothing to soak and is only re-energized just before a micro-switch being engaged or disengaged for the next stage of the process.

The machine would fill with only a small amount of water and the two wash plates would spin, tumbling the load within it, mimicking the action of a front-loading washer in a vertical-axis design.

The water then moves outward, up the sides of the basket, towards the center, and then down towards the agitator to repeat the process, in a circulation pattern similar to the shape of a torus.

Manufacturers have devised several ways to control the motion of the agitator during the wash and rinse separately from the high-speed rotation of the drum required for the spin cycle.

Hoovermatic machines were made mostly in twin-tub format for the European market (where they competed with Hotpoint's Supermatic line which used the oscillating agitator design) until the early 1990s.

Because less water is required, front-loaders typically use less soap, and the repeated dropping and folding action of the tumbling can easily produce large amounts of foam or suds.

Compared to top-loading washers, clothing can be packed more tightly in a front loader, up to the full drum volume if using a cotton wash cycle.

Nearly all front-loader washers for the consumer market also use a folded flexible bellows assembly around the door opening to keep clothing contained inside the drum during the tumbling wash cycle.

Commercial and industrial front-loaders used by businesses (described below) usually do not use the bellows, but instead require all small objects to be placed in a mesh bag to prevent loss near the drum opening.

Front-loaders need to use low-sudsing detergents because the tumbling action of the drum entrains air into the clothes load, which can cause excessive foamy suds and overflows.

For example, a small high-speed centrifuge machine may be provided in locker rooms of communal swimming pools to allow wet swimsuits to be substantially dried to a slightly damp condition after daily use.

These hoses are often exposed to full water pressure on a continuing basis and can deteriorate over time, developing bulges or weak spots that eventually cause leaks or catastrophic bursting and flooding.

An additional precaution is to install a washing machine inside a shallow metal or plastic pan, which can collect minor leakage and divert the water to a nearby drain, or to the outside of a building.

This makes the operation of the valves a quick procedure, but the washing machine user must still remember to turn off the water, even though the failure to do this produces no immediately obvious problems.

Efficiency became a selling point, both to save on running costs and to reduce carbon dioxide emissions associated with energy generation, and waste of water.

The coefficient is influenced by factors including the configuration of the washer (top-loading, front-loading), its spin speed, and the temperatures and the amount of water used in the rinse and wash cycles.

[146] Durability and functionality is more important than style; most commercial washers are bulky and heavy, often with more expensive stainless steel construction to minimize corrosion in a constantly-moist environment.

Commercial washers are often installed in long rows, with a wide access passageway behind all the machines to allow maintenance without moving the heavy machinery.

Originally, they were operated by coins (similar to older vending machines), but today they are activated by money accepting devices or card readers.

Many commercial washers offer an option for automatic injection of five or more different chemical types, so that the operator does not have to deal with constantly measuring out soap products and fabric softeners for each load by hand.

An industrial washer can be mounted on heavy-duty shock absorbers and attached to a concrete floor, so that it can extract water from even the most severely out-of-balance and heavy wash loads.

The machine may be mounted on hydraulic cylinders, permitting the entire washer to be lifted and tilted so that fabrics can be automatically dumped from the wash drum onto a conveyor belt once the cycle is complete.

Camille Paglia and others argue that the washing machine led to a type of social isolation of women,[148] as a previously communal activity became a solitary one.

[150] The following year, Swedish statistician Hans Rosling suggested that the positive effect the washing machine had on the liberation of women makes it "the greatest invention of the industrial revolution".

However, modern improvements have been made aiming to lower these emission numbers, and it depends on the user's choice to fully determine their environmental impact.