Washing Machine - Wikipedia

Washing by hand

edit Main article: Laundry § History

Laundering by hand involves soaking, beating, scrubbing, and rinsing dirty textiles. Before indoor plumbing, it was necessary to carry all the water used for washing, boiling, and rinsing the laundry from a pump, well, or spring. Water for the laundry would be carried, heated on a fire for washing, and then poured into a tub.[1] This meant the amount of warm, soapy water was limited; it would be reused to wash the least soiled clothing, then to wash progressively dirtier laundry.

Removal of soap and water from the clothing after washing was a separate process. First, soap would be rinsed out with clear water. After rinsing, the soaking wet clothing would be formed into a roll and twisted by hand to extract water. The entire process often occupied an entire day of work, plus drying and ironing.

Early machines

edit   A 1766 illustration of Schäffer's washing machine (left) and a simple, crank-operated washing machine (right)

 

An early example of washing by machine is the practice of fulling. In a fulling mill, the cloth was beaten with wooden hammers, known as fulling stocks or fulling hammers.

The first English patent under the category of washing machines was issued in 1691.[2] A drawing of an early washing machine appeared in the January 1752 issue of The Gentleman's Magazine, a British publication.[3] Jacob Christian Schäffer's washing machine design was published in 1767[3] in Germany.[4] In 1782, Henry Sidgier was issued a British patent for a rotating drum washer, and in the 1790s, Edward Beetham sold numerous "patent washing mills" in England.[1]

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. The person using the washer would use a stick to press and rotate the clothes along the textured sides of the basin or container, agitating the clothes to remove dirt and mud.[5] This crude agitator technology was hand-powered, but still more effective than actually hand-washing the clothes.

More advancements were made to washing machine technology in the form of the rotating drum design. These early design patents consisted of a drum washer that was hand-cranked to make the wooden drums rotate. While the technology was simple enough, it was a milestone in the history of washing machines, as it introduced the idea of "powered" washing drums. As metal drums started to replace the traditional wooden drums, it allowed for the drum to turn above an open fire or an enclosed fire chamber, raising the water temperature for more effective washes.

It was in the nineteenth century that steam power was first used in washing machine designs.[6]

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.[7]

The first United States Patent, titled "Clothes Washing", was granted to Nathaniel Briggs of New Hampshire in 1797. Because of the Patent Office fire in 1836, no description of the device survives. The invention of the washing machine is also attributed to Watervliet Shaker Village, as a patent was issued to an Amos Larcom of Watervliet, New York, in 1829, but it is not certain that Larcom was a Shaker.[8] A device that combined a washing machine with a wringer mechanism appeared in 1843 when Canadian John E. Turnbull of Saint John, New Brunswick patented a "Clothes Washer With Wringer Rolls".[9] During the 1850s, Nicholas Bennett of the Mount Lebanon Shaker Society at New Lebanon, New York, invented a "wash mill", but in 1858 he assigned the patent to David Parker of the Canterbury Shaker Village, where it was registered as the "Improved Washing Machine".[10][11][12]

 

Margaret Colvin improved the Triumph Rotary Washer,[13] which was exhibited in the Women's Pavilion at the Centennial International Exhibition of 1876 in Philadelphia.[14] At the same exhibition, the Shakers won a gold medal for their machine.[8]

Electric washing machines were advertised and discussed in newspapers as early as 1904.[15] Alva J. Fisher has been incorrectly credited with the invention of the electric washer. The US Patent Office shows at least one patent issued before Fisher's US patent number 966677[16] (e.g. Woodrow's US patent number 921195).[17] The first inventor of the electric washing machine remains unknown.[citation needed]

US electric washing machine sales reached 800,000 units in 1928.[18] However, high unemployment rates in the Depression years reduced sales; by 1932 the number of units shipped was down to about 600,000.[citation needed]

England established public washrooms for laundry along with bathhouses throughout the nineteenth century.[19] The term "laundromat" can be found in newspapers as early as 1884, and they were widespread by the time of the Depression. Patrons used coin-in-the-slot facilities to rent washing machines.[20][dubious – discuss]

Washer design improved during the 1930s. The mechanism was now enclosed within a cabinet, and more attention was paid to electrical and mechanical safety. Spin dryers were introduced to replace the dangerous power mangle/wringers of the day.

By 1940, 60% of the 25,000,000 electrically wired homes in the United States had an electric washing machine. Many of these machines featured a power wringer, although built-in spin dryers were not uncommon.[citation needed]

Automatic machines

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Bendix Home Appliances, a subsidiary of Avco, introduced the first domestic automatic washing machine in 1937,[21] having applied for a patent in the same year.[22] Avco had licensed the name from Bendix Corporation, an otherwise unrelated company. This first machine resembled modern front-loading automatic washers in both appearance and mechanical design.

Although it included many of today's basic features, the machine lacked any drum suspension and therefore had to be anchored to the floor to prevent "walking". Because of the components required, the machine was also expensive. For instance, the Bendix Home Laundry Service Manual (published November 1, 1946) shows that the drum speed change was facilitated by a two-speed gearbox built to a heavy-duty standard, like a smaller version of a car's automatic gearbox. The miniature electric motors used in the timers were also expensive to produce.

Early automatic washing machines were usually connected to a water supply via temporary slip-on connectors to sink taps. Later, permanent connections to hot and cold water became the norm. Most modern front-loading European machines now only have a cold water connection (called "cold fill") and rely completely on internal electric heaters to raise the water temperature.[23]

Many of the early automatic machines had coin-in-the-slot facilities and were installed in the basement laundry rooms of apartment houses.

 

World War II and after

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After the attack on Pearl Harbor, US domestic washer production was suspended for the duration of World War II in favor of manufacturing war materiel. However, numerous US appliance manufacturers were permitted to undertake the research and development of washers during the war years. Many took the opportunity to develop automatic machines, realizing that these represented the future of the industry.[24]

A large number of US manufacturers introduced competing automatic machines (mainly of the top-loading type) in the late 1940s and early 1950s. General Electric also introduced its first top-loading automatic model in 1947. This machine had many of the features that are incorporated into modern machines. Another early form of automatic washing machine manufactured by The Hoover Company used cartridges to program different wash cycles. This system, called the "Keymatic", used plastic cartridges with key-like slots and ridges around the edges. The cartridge was inserted into a slot on the machine and a mechanical reader operated the machine accordingly.

Several manufacturers produced semi-automatic machines, requiring the user to intervene at one or two points in the wash cycle. A common semi-automatic type (available from Hoover in the UK until at least the 1970s) included two tubs: one with an agitator or impeller for washing, plus another smaller tub for water extraction or centrifugal rinsing.[citation needed] These machines, as well as other older designs like the manual rotating drum, are still available, but are typically only used in circumstances where a standard water and power hookup for a washing machine is unavailable. Many are marketed for camping due to their light weight and ability to function without a water connection.

 

Since their introduction, automatic washing machines have relied on electromechanical timers to sequence the washing and extraction process. Electromechanical timers consist of a series of cams on a common shaft driven by a small electric motor via a reduction gearbox. 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). One of the first was invented in 1957 by Winston L. Shelton and Gresham N. Jennings, then both General Electric engineers. The device was granted US Patent 2870278.[25]

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. However, by the 1950s demand for greater flexibility in the wash cycle led to the introduction of more sophisticated electrical timers to supplement the electromechanical timer. These newer timers enabled greater variation in functions such as the wash time. 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. Fully electronic timers did not become widespread until decades later.

Despite the high cost of automatic washers, manufacturers had difficulty meeting the demand. Although there were material shortages during the Korean War, by 1953 automatic washing machine sales in the US exceeded those of wringer-type electric machines.

In the UK and most of Europe, electric washing machines did not become popular until the 1950s. This was largely because of the economic impact of World War II on the consumer market, which did not properly recover until the late 1950s. The early electric washers were single-tub wringer-type machines, as fully automatic washing machines were expensive.

During the 1960s, twin tub machines briefly became popular, helped by the low price of the Rolls Razor washers. Twin tub washing machines have two tubs, one larger than the other. The smaller tub in reality is a spinning drum for centrifugal drying while the larger tub only has an agitator in its bottom. Some machines could pump used wash water into a separate tub for temporary storage and to later pump it back for re-use. This was done not to save water or soap, but because heated water was expensive and time-consuming to produce. Automatic washing machines did not become dominant in the UK until well into the 1970s and by then were almost exclusively of the front-loader design.

In early automatic washing machines, any changes in impeller/drum speed were achieved by mechanical means or by a rheostat on the motor power supply. However, since the 1970s electronic control of motor speed has become a common feature on the more expensive models.

Cost-cutting and contemporary development

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Over time manufacturers of automatic washers have gone to great lengths to reduce costs. For instance, expensive gearboxes are no longer required, since motor speed can be controlled electronically. Some models can be controlled via Wi-Fi, and have angled/tilted drums to facilitate loading.[26][27][28]

Even on some expensive washers, the outer drum of front-loading machines is often (but not always) made of plastic (it can also be made out of metal, but this is expensive). This makes changing the main bearings difficult, as the plastic drum usually cannot be separated into two halves to enable the inner drum to be removed to gain access to the bearing.

Many residential front-loading washing machines typically have a 25 kg (55 lb) concrete block to dampen vibration.[29] Alternatives include a plastic counterweight that can be filled with water after delivery,[29] reducing or controlling motor speeds, using hydraulic suspensions instead of spring suspensions, and having freely moving steel balls or liquid contained inside a ring mounted on both the top and bottom of the drum to counter the weight of the clothes and reduce vibration.[30][31]

Most newer front-load machines now use a brushless DC (BLDC) motor directly connected to the basket (direct drive), where the stator assembly is attached to the rear of the outer plastic drum assembly, whilst the co-axial rotor is mounted on the shaft of the inner drum.[32] The direct drive motor eliminates the need for a pulley, belt, and belt tensioner.[33][34][35][36][37] It was first introduced to washing machines by Fisher & Paykel in 1991 in the Australasian market. Since then, other manufacturers have followed suit. Some washing machines with this type of motor now come with 10-year or 20-year warranties, and offer faster spin speeds (Fisher & Paykel models can reach max speeds of 1000-1100RPM).[38][39] The motor type used is typically an outrunner, due to its slim design with variable speed and high torque. The rotor is connected to the inner tub through its center. It can be made of metal or plastic. Some older direct drive washers use induction motors instead of BLDC motors.[40]

Additional features

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The modern washing machine market has seen several innovations and features, examples including:

• Washing machines including water jets (also known as water sprays, jet sprays[41] and water showers) and steam nozzles[42] that claim to sanitize clothes, help reduce washing times, and remove soil from the clothes.[43] Water jets get their water from the bottom of the drum, thus recirculating the water in the washer.[44][45][46]
• Others have special drums with holes that will fill with water from the bottom of the tub and redeposit the water on top of the clothes. Some drums have elements with the shape of waves, pyramids, hexagons, domes, or diamonds.[47][48][49][50]
• Some include titanium or ceramic heating elements that claim to eliminate calcium buildup in the element.[51] They can heat water up to 95 °C (203 °F).
• Some high-end models have lights built into the washer itself to light the drum,[42]
• Others have soap dispensers where the user fills a tank[52][53] with detergent and softener and the washing machine automatically doses the detergent and softener[54] and, in some cases, chooses the most appropriate wash cycle.[55] In some models, the tanks come pre-filled and are installed and replaced with new tanks, also pre-filled or refilled by the user, in a dedicated compartment on the bottom of the machine.[56]
• Some have support for single-use capsules containing enough laundry additives for one load. The capsules are installed in the detergent compartment.[57][58]
• Many dilute the detergent before it comes in contact with the clothes,[59][60][61][62][63] some by means of mixing the soap and water with air to make foam,[64] which is then introduced into the drum and improves cleaning performance.[65][66][67][68] Alternatively, micro bubbles may be used instead.[69][70]
• Some have pulsators that are mounted on a plate on the bottom of the drum instead of an agitator.[71][72][73] The plate spins, and the pulsators generate waves that help shake the soil out of the clothes. Many also include mechanisms to prevent or remove undissolved detergent residue on the detergent dispenser.[74][75][76]
• It is possible to incorporate a blower and a nozzle to smooth wrinkles in clothes without removing them from the washer.[77][78]
• Some manufacturers like LG Electronics and Samsung Electronics have introduced functions on their washers that allow users to troubleshoot common problems with their washers without having to contact technical support. LG's approach involves a phone receiving signals through sound tones, while Samsung's approach involves having the user take a photo of the washer's time display with a phone. In both methods, the problem and steps to resolve it are displayed on the phone itself.[79][80] Some models are also NFC enabled.[81] Some implementations are patented under US Patent US20050268669A1 and US Patent US20050097927A1.

 

In 1976 Servis released the world's first microcontroller operated washing machine, the Servis Selectronic 301.[82][83] In 1980 Hotpoint (UK) were the second manufacturer to produce a microcontroller based washing machine, the first of their top of line Microtronic series, the Hotpoint Microtronic X2000[84][85] both used chips from the Texas Instruments TMS1000 family of microcontrollers.

In the early 1990s, upmarket machines incorporated microcontrollers for the timing process. These proved reliable and cost-effective, so many cheaper machines now also incorporate microcontrollers rather than electromechanical timers. Since the 2010s, some machines have had touchscreen displays, full-color or color displays, or touch-sensitive control panels.[86][87]

In 1991, New Zealand-based company Fisher & Paykel introduced its SmartDrive washing machine line into the Australasian market, before entering the North American market around 1998. This line of washing machine uses a computer-controlled system to determine factors such as load size and adjusts the wash cycle to match. It also used a mixed system of washing, first with the "Eco-Active" wash, using a low level of recirculated water being sprayed onto the load followed by a more traditional style wash. The SmartDrive also included a direct drive brushless DC electric motor, which simplified the bowl and agitator drive by eliminating the gearbox system. The SmartDrive series is known for its high spin speeds of up to 1100RPM, excellent wash performance, reliability, and water/energy efficiency.

In 1994, Staber Industries released the System 2000 washing machine, which is the only top-loading, horizontal-axis washer to be manufactured in the United States. The hexagonal tub spins like a front-loading machine, using only about one-third as much water as conventional top-loaders. This factor has led to an Energy Star rating for its high efficiency. This type of horizontal-axis washer and dryer (with a circular drum) is often used in Europe, where space is limited, as they can be as thin as 41 cm (16 in) in width.[88]

In 2000, the British inventor James Dyson launched the CR01 ContraRotator, a type of washing machine with two cylinders rotating in opposite directions. It was claimed that this design reduced the wash time and produced cleaner washing than a single-cylinder machine. In 2004 the launch of the CR02, was the first washing machine to gain the British Allergy Foundation Seal of Approval. However, neither of the ContraRotator machines is now in production as they were expensive to manufacture. They were discontinued in 2005.[89][90] It is patented under U.S. Patent US7750531B2, U.S. Patent US6311527, U.S. Patent US20010023513, U.S. Patent US6311527B1, U.S. Patent USD450164.[91]

In 2001, Whirlpool Corporation introduced the Calypso, the first vertical-axis high-efficiency washing machine to be top-loading. A washplate in the bottom of the tub nutated (a special wobbling motion) to bounce, shake, and toss the laundry. Simultaneously, water containing detergent was sprayed onto the laundry. The machine proved to be good at cleaning but gained a bad reputation due to frequent breakdowns and destruction of laundry. The washer was recalled with a class-action lawsuit[92] and pulled off the market.

 

In 2003, Maytag introduced their top-loading Neptune TL FAV6800A and TL FAV9800A washers. Instead of an agitator, the machine had two washplates, perpendicular to each other and at a 45-degree angle from the bottom of the tub. 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.[93][94][95][96][97][98]

In 2006, Sanyo introduced the "world-first" (as of February 2, 2006, with regards to home use drum-type washer/dryer) drum-type washing machine with "Air Wash" function (i.e.: using ozone as a disinfectant). It also reused and disinfected rinse water.[99] This washing machine uses only 50 L (11.0 imp gal; 13.2 US gal) of water in the recycle mode.

Approximately in 2012, eco-indicators were introduced, capable of predicting the energy demand based on the customer settings in terms of program and temperature.[100]

Features available in most modern consumer washing machines:

• Delayed execution: a timer to delay the start of the laundry cycle
• Predefined programs for different laundry types
• Rotation speed settings
• Variable temperatures, including cold wash

Additionally, some modern machines feature:

• Child lock[101]
• Steam
• Time remaining indication
• Extra water/rinse.
• UV disinfection.[102]

Around 2015 and 2017, some manufacturers[103][104][105] (namely Samsung and LG Electronics) offered washers and dryers that either have a top-loading washer and dryer built on top of a front-loading washer and dryer respectively (in Samsung washers and dryers) or offer users an optional top-loading washer that can be installed under a washer or dryer (for LG washers and dryers) Both manufacturers have also introduced front-loading washers allowing users to add items after a wash cycle has started,[106][107] and Samsung has also introduced top-loading washers with a built-in sink[108] and a detergent dispenser that claims to leave no residue on the dispenser itself. In IFA 2017,[109] Samsung released the QuickDrive, a front-loading washer similar to the Dyson ContraRotator but instead of two counter-rotating drums, the QuickDrive has a single drum with a counter-rotating impeller mounted on the back of the drum. Samsung claims this technique reduces cycle times by half and energy consumption by 20%. The US has introduced standards for washing machines that improve their energy efficiency and reduce their water consumption.[110][111]