Duplo (Lego)

Lego currently makes Duplo sets licensed with Dora the Explorer, Bob the Builder, and Thomas the Tank Engine characters as well as a new castle theme. Valves of this type using a cylinder rather than a cone are sometimes encountered, but using a cone allows a tight fit to be made even with moderate manufacturing tolerances. As of 2005 there are currently two other Duplo-related Lego systems:. A hole through the cone allows the fluid to pass if it is lined up with the openings in the socket through which the fluid enters and leaves; turning the cone using the handle rotates the passage away, presenting the fluid with the unbroken surface of the cone through which it cannot pass. In the 2004 spring catalog there was a reminder that Duplo was now called Explorer, but that fall the well known Duplo name was back yet again with a new rabbit logo. A cone valve consists of a shallowly-tapering cone in a tight-fitting socket placed across the flow of the fluid. The name Duplo was dropped again in favor of Explore in 2002. They can be identified by their range of only 90º between fully-on and fully-off - usually when the handle is in line with the pipe the valve is on, and when the handle is across the pipe it is closed.

1993 brought a grey rail train system with a stop and start track. Cone valves are usually found in gas taps (and, incidently, the cask beer taps referred to above). These used internal screws to stay together. In the UK this type of tap normally has a wheel-shaped handle rather than a crutch or capstan handle. In 1992, Duplo Toolo was introduced. There is no resistance to flow when the tap is fully open, but this type of tap rarely gives a perfect seal when closed. This included a Duplo people mother, father, and smaller child. Gate valves use a metal disc the same diameter as the pipe which is screwed into place perpendicularly to the flow, cutting it off.

In 1986, a Duplo doll house with sliding doors was introduced. For high pressure domestic water systems this does not matter, but for low pressure systems where flowrate is important, such as a shower fed by a storage tank, a "stop tap" or, in engineering terms, a "gate valve" is preferred. Also in 1983, set number 2700 was introduced with a model of a steam engine with two train cars. This is called a "globe valve" in engineering and, while it gives a leak-proof seal and good fine adjustment of flow, the tortuous S-shaped path the water is forced to follow offers a significant obstruction to the flow. These figures have a moveable head, arms, and legs and look like large Lego minifigures, but the Duplo people cannot be taken apart for safer handling by small children. Most taps use a soft washer which is screwed down onto a seat in order to stop the flow. In 1983, other Duplo figures appeared, often called Duplo people. One reason that most beer taps are not designed for adjustable flow is that the beer itself is damaged by the pressure drop in a choked-flow valve: holding a beer tap partially open causes the beer to foam vigorously, ruining the pour.

The name Duplo was brought back in 1979 along with a new Duplo logo with a rabbit. At very low flow settings, the viscosity of the water becomes important and the pressure drop (and hissing noise) vanish; at full flow settings, parasitic drag in the pipes becomes important and the water again becomes quiet. The new sets included figures, doors, and 2 by 6 knob wagons that could act as a car or train. Bubbles of cool water vapor form and collapse at the restriction, causing the familiar hissing sound. Another new brick was a half arch. At intermediate flow settings the pressure at the valve restriction drops nearly to zero from the venturi effect; in water taps, this causes the water to boil momentarily at room temperature as it passes through the restriction. They included a head and body, but had no legs. The choked flow rate is independent of the viscosity or temperature of the fluid or gas in the pipe, and depends only weakly on the supply pressure, so that flow rate is stable at a given setting.

Small figures the size of 2 by 2 knobs were introduced as well. Turning the knob or working the lever sets the flow rate by adjusting the size of an opening in the valve assembly, giving rise to choked flow through the narrow opening in the valve. In 1977 the Duplo name was dropped in favor of Lego Preschool. Most water and gas taps have adjustable flow. With these new Duplo sets, Lego is targeting children 1½ years old with the idea that when the children reach 3 the Duplo bricks can be used together with Lego bricks. Although a gas tap may be a valve that releases any gas, the word is most commonly used to refer to taps that control the flow of natural gas in the home (for gas fires) or in school science laboratories (for Bunsen burners). This wagon, and its coupler system, is still sold today. A "beer tap" now may be one of several items:.

New additions included a round-topped 2 by 2 knob brick and a small 4-wheel wagon with two rows of 6 knobs. This may be because the word was originally coined for the wooden valve in traditional barrels. In 1975 Duplo became its own product, with five sets made up exclusively of Duplo bricks. While in other contexts, depending on location, a "tap" may be a "faucet", "valve" or "spigot", the use of "tap" for beer is almost universal. In 1972, the Duplo brick with 2 rows of 2 knobs was introduced and continues to be included in sets today. This convention applies in the UK too, but many installations exist where it has been ignored. In the product catalog for 1971, the sets were targeted at children from 1 to 2 years, but still sold mixed with Lego bricks, normally designed for ages 3 to 12. In some countries there is a 'standard' arrangement of hot/cold taps: for example in the United States the hot tap is generally on the left.

The following year, two more sets were added with blue and red wheel plates with 4 rows of 8 knobs. Mixer taps may have a red-blue stripe or arrows indicating which side will give hot and which cold. The number 510 has been reused to name other Lego sets. The cold tap generally has a blue or green indicator and/or is labeled C or Cold. Both sets were designed to target younger children. In English-speaking countries, the hot tap generally has a red indicator and/or is labeled H or Hot. Set number 510 had 9 Duplo bricks mixed with 8 Lego bricks, while set 511 had 19 Duplo bricks and 8 Lego bricks. If separate taps are fitted, it may not be immediately clear which tap is hot and which is cold.

The knobs stick out less than current Duplo bricks, and the holes had four tags for a better grip with traditional Lego bricks. Latest designs do this using a built in thermostat. The bricks were available in four colors: red, yellow, blue, and white. This is a single, more complex, valve whose handle moves up and down to control the amount of water flow and from side to side to control the temperature of the water (achieved by mixing the hot and cold water together). The first Duplo bricks, with 2 rows of 4 knobs, appeared in 1969. In kitchens, and in the US and many other places, mixer taps are often used instead. The most common sets are the farm, zoo, police station, fire station, airplane, and train sets. Water for baths, sinks and basins can be provided by separate hot and cold taps; this arrangement is common in the UK, particularly in toilets.

Many Duplo sets have reappeared multiple times over the years. . The Duplo product line changes from year to year — even the name Duplo had been dropped twice. In American English the usage is sometimes more specialised, with the term tap restricted to uses such as beer taps and the word "faucet" used for water outlets; although some Americans use "tap" in the broader sense as well. Since 1977, Duplo has made sets with figures, cars, and houses. For example, in Commonwealth English the word is used for any everyday type of valve, particularly the fittings on bathtubs and sinks. Despite their size, they are still compatible with traditional Lego bricks. A tap is a valve for controlling the release of a liquid or gas.

Duplo bricks are twice the size of traditional Lego bricks, and are easier to handle for younger children. In an analogy to controlling the flow of a fluid, tap can also refer to drawing electricity from a certain winding in an electrical transformer. Duplo is a version of Lego bricks from the well known Danish toy company, LEGO Group. To tap a vessel containing liquid metal is to remove the liquid from the vessel, even if no valve as such is utilised in the process. Baby bricks can be stacked on Quatro, Duplo, or Lego bricks but the large rounded knob prevents other systems from stacking on it. It has a single large round knob and is twice the size of Lego Quatro, making it four times the size of Duplo or eight times the scale of Lego bricks.

Lego Baby (formerly called Primo) is for children as young as 6 months. These bricks are twice the size of the Duplo bricks and can be used together with Duplo bricks. Lego Quatro is for children 1 to 3 years old.