Lava lamp

A lava lamp is a lamp which is mixed with the released thermal energy of an incandescent lamp, a liquid in motion. The lights were in the 1970s popular furnishings for decoration and experienced a rediscovery in the 1990s.

Construction

The lamp consists of a bottle-like vessel under which a light bulb is attached. In the vessel there are two inter- insoluble substances, both of which are liquid at the operating temperature and have a similar density, but have different thermal expansion coefficients.

Common are mixed with water and salts, for example, combinations of ( hydrophobic ) wax or oil ( hydrophilic ) isopropanol or ethylene glycol, optionally in order to increase the density. By adding appropriate dyes results in operation, the eponymous lava or magma appearance.

About the bulb of the vessel contents are both illuminated and heated. The wax is viscous. The ascent and descent of a ( mostly hydrophobic ) substance is due to its greater thermal expansion. By heating its density decreases faster than that of the other liquid. This causes a buoyancy which can ascend the material in the form of large bubbles. The cooling in the upper part of the vessel reverts the effect, the liquid drops again and the cycle begins anew.

The substances used in some lava lamps such as benzyl alcohol or (formerly ) carbon tetrachloride are harmful to health, a broken lava lamp should therefore be disposed of properly.

Operation

Lava lamps need, depending on MODEL 30 minutes to three hours to heat and should not be operated for longer than eight hours at a time to avoid damage.

History

The physical laws of the different spatial thermal expansion of different materials, which is based on the function of the lava lamp, are already well known and form one of the phenomena that are repeatedly re-discovered or explored experimentally. An example of this is an excerpt from a book serve, which is now over 100 years old:

"In addition, CR Darling described an experiment in which a water-filled vessel which is heated from below to about 80 ° C, was used, and was poured into the aniline. At a temperature around 63 ° C. the aniline has the same specific weight as water. With increasing heating it expands more than water and is easier hotter and harder the colder it is. The aniline soon as large bubble accumulates on the surface, the bubble is cooled and sinks to the bottom of the vessel where it is heated again. Soon after, new bubbles form there which rise to the surface. This process continues, with unchanged conditions, continuing indefinitely. It is interesting to observe the outgoing and incoming in ever new formations of bubbles. "

Sometime around the time of World War II to the Englishman Donald Dunnet have tried using the principle described to develop an innovative egg timer. Whether these domestic help was ever completed, is not known. But it is well established that a designed by Dunnet forerunner of the lava lamp as eye catcher found its way into the Queen's Head Pub in New Forest, England.

Around the year 1950 discovered the Singapore-born Briton Edward Craven Walker in this very pub a fascinating lamp in which was one of two liquids contained therein in constant motion. Walker took on the idea to develop a version of it on his own terms. It is certain that Walker 1963, after years of development work, distribute the meantime the name "Astro Lamp" baptized lava lamp the company Crest Worth Limited founded. The name Crestworth can be had in like with " fame worth " or " award-worthy " translate. However, the prestigious London department store Harrods had no interest in the innovative product.

Two businessman from Chicago, Adolph Wertheimer and Hy Spector, was discovered in 1965 on a product fair in Hamburg Walkers lava lamp and acquired the manufacturing and sales rights for the U.S. market. Craven Walker was technical advisor of their company. Upon her return from Europe, they created the "Lava Manufacturing Corporation, Chicago, Illinois ," called the product "Lava Lite " and started the production and distribution of a first series. From the lava Mfg.. Corp.. later became the basis of change of ownership Lava Simplex Incorporated.

In the late 1960s and early 1970s, the lava lamp was finally known. Since then, she is a cult object. However, at the beginning of the 1980s lava lamp experienced a veritable depression. The sales figures fell sharply worldwide. As a result, the recently renamed American company Lava Simplex International went into the possession of Haggerty Enterprises. In the late 1980s, the Ltd. Crest Worth was. shrunk to the size of a family business. Compared to the millions strong production figures of the 1970s, the production of a few ten thousand lamps per year took modest. The lava lamp of the New Age generation was known under the name The Wave and was also distributed in the U.S. by a company of Haggerty Enterprises.

In the late 1980s presented Cressida Granger, who also sold cars with lava lamps on their London flea market stall, found that the demand steadily increased at a new generation of customers. First, they made ​​contact with the company Crest Worth to secure supplies for their stand. But soon she realized the upcoming retro wave. Instead of initially planned to open a retail outlet, there was a meeting with the "Father of the lava lamp " in which Craven Walker a lucrative offer for Granger and her business partner David Mulley had: He offered the two 20 percent of his company in order to to bring back into the black. If successful, the respective partnerships should then be changed so that Granger and Mulley would principal owner of the company. It came to the establishment of a new society, the crest Worth Trading Limited. Later Granger changed the company name in the course of modernization measures in Mathmos, the name of lavaartig bubbling lake of absolute evil from the 1970s cult film classic " Barbarella ".

Mid-1990s was the lava lamp in the USA again as popular as in its heyday. Haggerty Enterprises founded the subsidiary Lava World International. Mathmos added to the product line in 2000 with the " Fluidium " a new model for the new millennium added, but also so that the coming end of the retro trends did not stop. Meanwhile, magma lamps from the Far East were on the rise and flooded the world market.

The two major patent holders, Mathmos and Lavaworld have, the market is more or less divided among each other. Especially Lavaworld strives to revive the market again and again, so they provide, among other things regularly especially among collectors coveted because usually limited, special editions. But third-party find their markets.

Rights

Over time, different rights were registered in connection with the lava lamp and granted. For the original rights (20 years, utility max. Patents 10 years max. ) Is the legal protection period expired. In the U.S., a commodity form brand was registered in 1997, which is basically unlimited. Any attempt to register as a commodity form mark the shape of the Astro lamp in Germany also failed 2004 last instance before the Federal Patent Court " because of lack of any distinctive character '.

1950 - The precursor of the lava lamp

Claims for the " Display Device using Liquid Bubbles in another liquid" are

The possible embodiments disclosed by Dunnet assigns the lamp provided with a reflector on right back of the container, comprises a plate with openings mounted obliquely forward and downward and the rear top between the two liquids, and a black coloring of the glass container in the rear lower portion. He describes other options for individual components, the use of dyes, a thermostat or an internal heating, which is partially enclosed by an enclosure with chimney -like opening. Dunnets invention thus uses already many essential components and physical principles, which are also used in Walker's lava lamp.

Patent " Display Device " 1964 - the Lava Lamp

Claims are

Further claims are the use of a wax additive, paraffin wax or petrolatum, the use of a specific sealing construction for the cap, a light bulb with the container, the colored water, a surface tension breaker, possibly in the form of a spiral wire, the bottom of the container and finally, the use of a support for the container in which the lamp is fitted.

Utility model " container for decorative purposes ", valid from 1965 in Germany

The protective claims relate to the shape and the closure of the container and the structure of the lamp, including the use of so-called surface tension breaker, optionally as a wire spiral.

1965 - Changed Lavaformel

Claims are further possibilities of composition of the two liquid components, particularly the lipophilic phase. On this and the following patent shows that already different ingredients were used in the original manufacturer over time.

1967 - Altered water formula

Claims are further possibilities for the composition of the two liquid components, in particular the aqueous phase.