GB2399446A

GB2399446A - Decorative lamp with separate heating and lighting sources.

Info

Publication number: GB2399446A
Application number: GB0303419A
Authority: GB
Inventors: Martin Herbert
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-02-13
Filing date: 2003-02-13
Publication date: 2004-09-15
Also published as: GB0303419D0

Abstract

A decorative lamp comprises a container, one or more heating members 12 and one or more lighting members 11. The container holds a first substance 6 which is liquid at room temperature and a second substance 7 which has a differing relative density to the first substance at predetermined temperatures. The second substance is preferably a paraffin based substance immiscible with the first substance and the lamp is in the form of a lava-lamp. The heating member may be in the form of a rope heater, mica strip heater or heated fluid passed through pipes. The lighting members may be in the form of LEDs, bulbs, UV black lights, fluorescent tubes, neon tubes and strobes. One of the substances may be phosphorescent or be thermochromic. A control circuit linked to a thermostat 15 may be provided to control the heating member.

Description

Background / Summary

Lamps of the type commonly referred to, as "lava lamps" are well known in the art. An example of one such device is described in U.S. Pat. No. 3. 387.396 to Smith. As is commonly known, such lamps typically comprise a container which holds a paraffin based substance and a liquid substance. A heating element, typically in the form of a light bulb, situated beneath the bottom surface of the container heats the paraffin-based substance causing it to become flowable.

When the paraffin-based substance is sufficiently heated, globules are formed which are less dense than the liquid and therefore rise and circulate within the container. As the globules approach the top surface of the container they cool, become denser and fall back toward the bottom surface combining once again to form one uniform mass. The lamp and its contents are continuously illuminated throughout its use by the light emitted from the bulb.

The prior art is limited in that it combines the heating and lighting effects for the lamp into one member, most commonly a light bulb. This has a number of drawbacks, which limit the lamp's potential shapes, functions and uses.

Firstly the shape and overall dimensions of the lamp are defined by the light bulb. The power of the light bulb determines the heat transmitted into the lamp and therefore the overall height to which the paraffin wax can achieve. However, the use of a more powerful lighting source does not guarantee a proportionally larger lamp with the same effects. If the bulb is replaced by a more powerful one the temperature in the lower parts of the container is too great to form a solidified globule of paraffin wax. Resultantly the paraffin wax forms globules higher in the container but do not fall to the lowest point. Instead the wax will move around a small portion in the middle of the lamp, hence this does not provide the aesthetic effects desired. Thus the lamp is limited to a small range of shapes and sizes to accommodate for the bulbs heating effects.

Secondly the aforementioned lamp is not efficient. Mounting the heating source exterior to the container requires the outside of the lamp to be at a higher temperature than that of the inside for the heat to transfer into the contents. This results in a great deal of the heating energy being lost in bringing the whole casing to the desired temperature in order for the substances to become flowable. This amounts to a less efficient lamp, which requires a great deal of time to heat up and cool down. While in use, and for a time following use while the casing cools there exists a significant risk of burning to anybody touching the lamp. This risk is noteworthy in that the lamp could appear to be off but still hot and an unsuspecting person may assume the lamp is cold and attempt to move it.

Thirdly, in the prior art, it is not possible to use low power bulbs or other exotic lighting systems such as ultra-violet lamps or light emitting diodes (LEDs), as these commonly do not provide adequate power to heat the container.

Over the years, no significant changes have been made to such lamps to improve the visual effect of the same. Accordingly, it is the main object of the present invention to provide a lamp of the type described above with improved functionality, safety, efficiency and visually perceptible features.

The present invention is directed toward a lamp and, more particularly, to such a device which includes a container with two or more substances of differing relative densities therein. The application of heat to the substances at the bottom of the container causes the substance with the initially greater relative density to rise in the other substance and flow around.

The invention uses a separate heating and lighting member. The heating member supplies the heat while a separate lighting member illuminates the lamp to provide an aesthetically pleasing visual effect.

Preferably the heating member is mounted within the interior of the casing allowing a more efficient transfer of heat thus overcoming the problems of the prior art and improving the safety therein.

Summary of the Invention

In accordance with the illustrative embodiments, demonstrating features and advantages of the present invention, there is provided a lamp, which comprises a transparent or other light- transmitting (such as opaque) container mounted within a casing member. In the preferred embodiment two substances are received in the container although more could be used without departing from the scope of the invention. The substances may utilise varying properties. In one embodiment the substances are plain colours. In a second embodiment the substances may have a phosphorescent or incandescent "glow-in-the-dark" nature. In a third embodiment the substances may exhibit thermochemical virtues by changing colour with the increasing of temperature. One of the substances has a higher relative density and is immiscible with the other substance.

Upon application of heat, which is supplied by a heating source preferably mounted within the container, globules of the substance with the initially higher relative density become less dense, rise in the other substance and flow around the container. As the globules rise toward the top surface of the container they cool, drop back down toward the bottom surface of the container and rejoin with other globules to once again form one uniform mass.

In the preferred embodiment the internal heating source is a rope heater powered from an external electricity supply. In a second embodiment the heating source is a mica strip heated from an external electricity supply. In a third embodiment the heating source is a fluid passed through pipes that pass through the container. The heating for the pipe liquid is provided by some external source, preferably mounted within the casing of the lamp. Other methods commonly known for heating liquids electrically could be used in heating the containers contents without departing from the scope of this invention.

By providing heat internally the substances in the container are heated more efficiently as energy is not lost heating the container or directly to the surrounding environment. Resultantly a quicker time is achieved to bring the contents to the desired temperature. As the heating element can be constructed to cover the entirety of one or more surfaces inside the container a more uniform distribution of heating can occur in the liquid at the bottom of the container.

The notably lower temperature of the exterior of the lamp greatly reduces the chance of accidentally burning or igniting any objects coming into contact. This significantly reduces any fire risks and allows for the possibility of cheaper and safer materials to be used in construction of the lamp. An example of this would be to replace the traditional glass container with a plastic substitute reducing the chance of a dropped lamp smashing and splashing its hot contents.

The efficiency of the invention can be most clearly seen with reference to figure 6, which shows the heating curve of the invention vs. a prior art lamp of similar volumetric size. The invention (B) heats up the container contents to the desired working temperature within one minute of operation while the prior art lamp requires a further ten minutes or so (A).

Furthermore, with reference to figure 7, which show the temperatures of the lamp casings, it can be seen that the prior art casing (A) rapidly exceeds 100'C within ten minutes, a temperature which could result in severe burns, while the invention (B) casing never rises above the maximum internal temperature of 65'C.

Another advantage of a separate heating member is that the container can take any shape.

Prior art devices use generally circular shaped lamps, which thin towards the top edge because of the size and dimension restrictions of the light bulb heating source. The bulb is generally housed within a circular casing at the bottom of the lamp to which the substance container screws tightly into. As the bulb is rounded, to gain a lamp of minimal dimensions and most efficient heating the container must also be rounded.

The invention described utilises a heating member that can be any shape. In the preferred embodiment this heating member is a rope heater, which can be bent into any desired shape.

Thus any shaped containers can be used. Furthermore, by constructing the container as a thin rectangular container (as shown in figure 2.) it allows for the lamp to be wall mounted.

The lamp then may have a much wider range of locations for use, as it is no longer constrained to a lamp that must be placed upon a table or shelf. In another embodiment the container side that is mounted closest to the wall may be replaced by a mirrored surface so that the lamp becomes a decorative mirror.

Lighting of the container is provided by a separate light source. In the preferred embodiment this is achieved through the use of LEDs. In a second embodiment one or more light bulbs are used. Other lighting sources can be used as the lighting member is not required to provide the heating member, thus cheaper and lower energy consumption components can be used.

As can be appreciated by someone in the art, use of 'exotic' lighting systems such as UV black light, neon tubes, LED scrolling dot matrix and/or strobes can be used to provide interesting decorative variations as the lighting member need not provide any heat to the container. This allows the lamp to be used as an advertising medium as well as a decorative feature. Other lighting sources could be used without departing from the scope of the invention.

Furthermore, as the lighting member is separate to the heating member the lighting can be placed anywhere in or out of the container to provide a range of lighting effects.

Other objects, features and advantages of the invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the drawings.

Detailed description of the preferred embodiment

Referring now to the drawings in detail wherein like reference numerals have been used throughout the various figures to designate like elements, there is shown in the figures a lamp constructed in accordance with the principles of the present invention and designated generally as 1.

The lamp 1 includes a transparent container 2 with a top surface 3 and a bottom surface 4, (FIG. 1). The container is preferably comprised of a clear plastic, such as a laminated polycarbonate although other embodiments may use glass or other such materials. In a preferred embodiment, the container is rectangular (thin-box) shaped. However, the container 2 can be formed of any shape.

The container 2 has an opening or fill spout 5 formed through the top surface 3 as shown in FIG. 1. A first substance 6, which is liquid at room temperature, is poured through the opening until the container is substantially filled. Preferably, the first substance is comprised of water / monopropylene glycol mixture. A dye can be added to the liquid substance 6 to provide an aesthetically pleasing colour. A second substance 7 is also inserted through the opening 5 in the top surface 3 of the container 2. The second substance is immiscible with the first substance.

In the preferred embodiment, the second substance is comprised of a paraffin-based material of the type described in U.S. Pat. No. 3.387.396 to Smith. However, the second substance 7 can be comprised of other materials which have a higher relative density than the first substance 6 at room temperature and which have a lower relative density than the first substance at a higher temperature. In the preferred embodiment the two substances should be of contrasting colour so that they can be readily visually distinguishable from one another.

Contrasting colour could be different shades of one colour or different colours altogether.

The paraffin-based material 7 is solid at room temperature and has a surface tension, which prevents the same from sticking to the walls of the container. Additionally, at room temperature, the paraffin based material settles on the bottom surface 4 of the container 2 as one uniform mass as best illustrated in FIG. 2.

Once the contents of the container have been received therein, the opening 5 in the top surface of the container is sealed by a cap 8, which is secured over the same.

Extending along the lower interior of the container is a heating member 12. The heating member is preferably in the form of a 50W 240V electric rope heater housed within a sealed watertight tube 13 which heats the paraffin based material 7 located adjacent the bottom surface 4 of the container 2. The use of a watertight tube allows for the use of a rope heater, which is not chemically resilient. This greatly reduces the cost of manufacture.

The sealed watertight tube 13 passes from the container to the casing member 9. In the preferred embodiment the tube 13 passes through the side of the container 2. In other embodiments the tube 13 passes directly through the casing (either upper or lower) or the container.

A 240V (ac) electrical supply 14 connects up to the heating member to provide power for heating outside of container 2. In the preferred embodiment the electrical supply 14 is mounted within the lower casing member 9.

Control of the rope heater is obtained using a thermostat 15 mounted within the upper portion of container 2 so as to monitor the temperature of the surrounding fluid at the top of the container and allow activation of the rope heater accordingly. The temperature at the top of container 2 is monitored so as to keep it at the temperature where the globules solidify and fall back to the bottom of the container. For the preferred substances this temperature is 45'C.

A suitable thermostat is the Campini TY60 produced by HHV Components. Referring to figure 3 this thermostat is connected to the electrical supply 14 and rope heater 12. The thermostat is switched on at a temperature less than 45'C providing an electrical supply to rope heater 12. At temperatures greater than 45'C the thermostat is in an off state and the rope heater 12 has no electrical supply. The thermostat and associated electronics are well known to anyone with even a limited knowledge in the art and as such will not be discussed within this application.

As the paraffin based material 7 is heated to a suitable temperature, typically between 45 and 60 C., it becomes flowable about the liquid substance 6 of the container 2. Globules 19 of the paraffin-based material 7 are also formed as substance 7 is heated (FIG. 2). Furthermore, the substance 7 becomes less dense. When the relative density of the globules falls below the relative density of the liquid substance, the globules rise and circulate in the container. As the globules approach the top surface 3 of the container 2, they begin to cool and become denser. When the relative density of each of the globules becomes greater than the relative density of the liquid substance 6, the globules 19 fall back down toward the bottom surface 4 of the container 2 where they re-unite with other globules that have already descended.

Referring to figure 1. A light source 11 also serves to illuminate the container 2 and the contents thereof in order to provide a pleasing visually perceptible appearance. In the preferred embodiment this light source is mounted within lower casing member 9 to provide an upward light. As can be clearly seen the light source 11 could equally be housed within the upper casing member 10 to provide a down lighting effect. Furthermore, the light source could be mounted along the side of container 2 to provide a direct light through effect.

In the preferred embodiment light source 11 is a bank of LEDs. Other light emitting components could be used such as light bulbs, fluorescent tubes, neon tubes, black light tubes, and strobes without departing from the scope of the invention.

Referring to again to Figure 3., electrical supply 14 is connected to transformer 16 and rectifier block 17 to provide a steady low voltage DC electrical supply to the LED bank 11.

In the preferred embodiment the signal to the LED bank is further controlled by controller module 18, placed in series between rectifier block 17 and LED bank 11 to provide an intermittent signal to the LEDs producing a "pulsing" aesthetic effect. For reference; below are described three embodiments of controlling the LED bank.

Referring to figure 4. In this embodiment of the controller module the flashing speed of the LEDs can be adjusted and various dancing patterns of lights can be formed. The controller module 18 circuit consists of two astable multivibrators. Transistors T1 and T2 form one multivibrator while the other astable multivibrator is formed by T3 and T4. The Duty cycle of each multivibrator can be varied by changing RC time constant. This is achieved through potentiometers VR1 and VR2 to produce different dancing pattern of LEDs. Alternatively light dependent resistors could replace the potentiometers so that dancing of LEDs will depend upon the surrounding light intensity. Furthermore, the potentiometers could be replaced by a microphone and amplifier stage so that the flashing rate of the LEDs is dependent on the amount of ambient noise detected.

Referring to figure 5 controller module 18 is used as a running message display circuit wherein letters or pictures formed by LED arrangement light up progressively. Once all the "letters" of the message have been lit up, the circuit gets reset to its off state and then repeat over.

As can be seen in figure 5 the circuit utilises a Johnson decade counter CD4017BC (IC2). A NE555 (ICI) timer is connected as a 1 Hz astable multivibrator, which clocks the IC2 for sequencing operations. Initially in the circuit only one of the ten CD4017BC (IC2) outputs remains high and the other outputs switch to high state successively on the arrival of each clock pulse from the timer.

On reset, output pin 3 goes high and drives transistor T7 to 'on' state. The output of transistor T7 is connected to fetter 'W' of the LED word array (all LEDs of letter array are connected in parallel) and thus fetter 'W' is illuminated. On arrival of first clock pulse, pin 3 goes low and pin 2 goes high. Transistor TO conducts and letter 'E' lights up. The preceding letter 'W' also remains lighted because of forward biasing of transistor T7 via diode D21. In a similar fashion, on the arrival of each successive pulse, the other letters of the display are also illuminated and finally the complete word becomes visible. On the following clock pulse, pin 6 goes to logic 1 and resets the circuit, and the sequence repeats itself. The frequency of sequencing operations is controlled with the help of potentiometer VR1.

The display can be fixed on a printed circuit board of suitable size and mounted at 45' within the housing so as to display its message onto the front of the lamp. In another embodiment two circuits can be connected in a similar fashion and multiplexing of LEDs can be done to give a moving display effect While no novelty is claimed in this invention for the lighting methods, as can be appreciated by the above examples, the use of low power light sources, such as LEDs, which do not require provision of a heating function allows a wide range of digital applications to be implemented.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and accordingly reference should be made to the appended claims rather than to the foregoing specification as indicating the scope of the invention.

Brief description of the drawings

For the purpose of illustrating the invention, there is shown in the accompanying drawings one form, which is presently preferred; it being understood that the invention is not intended to be limited to the precise arrangements and instrumentalities shown.

FIG 1 is a perspective view of a lamp according to the present invention; FIG. 2 is a perspective view of the present invention showing heated globules rising and falling around the lamp that is filled with a liquid substance.

FIG. 3 shows a block diagram for the lamp electronics.

FIG. 4 shows a circuit diagram of the preferred LED controller module FIG 5 shows a circuit diagram for the invention with a running message display FIG 6 shows a graph of lamp internal temperature (i.e. within the container) over time. The prior art existing lava lamp is marked A, the invention B. FIG 7 shows a graph of lamp external temperature (i.e. the casing) over time. The prior art existing lava lamp is marked A, the invention B.

Claims

What is claimed is 1. A decorative lamp comprising: a container; À one or more heating members; one or more lighting members; a first substance within said container, said first substance being a liquid at room temperature; One or more other substances within said container, said substances having a differing relative density than said first substance at predetermined temperatures.
2. The decorative lamp of claim 1 wherein said container is transparent.
3. The decorative lamp of claim 1 wherein said second substance is comprised of paraffin based substance.
4. The decorative lamp of claim 3 wherein said second substance has phosphorescent properties.
5. The decorative lamp of claim 3 wherein said second substance has thermochemical properties.
6. The decorative lamp of claim 1 or any preceding claim wherein said heating member is positioned so as to heat the contents of said container.
7. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is a mica strip.
8. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is a rope heater.
9. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is a ceramic heater.
10. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is an incandescent bulb.
11. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is a surface heater. ll
12. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is a tubular or coiled heater.
13. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is an incandescent bulb.
14. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is contained within said container walls.
15. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is mounted within said container.
16. The decorative lamp of claim 6 or of any preceding claim wherein said heating member is mounted externally to said container.
17. The decorative lamp of claim 6 or of any preceding claim wherein the activation of said heating member is controlled by a control circuit.
18. The decorative lamp of claim 1 or of any preceding claim wherein said lighting member is positioned so as to illuminate the contents of said container
19. The decorative lamp of claim 18 or of any preceding claim wherein said lighting member comprises one or more light emitting diodes.
20. The decorative lamp of claim 18 or of any preceding claim wherein said lighting member comprises an electro luminescent material.
21. The decorative lamp of claim 18 or of any preceding claim wherein said lighting member comprises one or more incandescent bulbs.
22. The decorative lamp of claim 18 or of any preceding claim wherein said lighting member comprises one or more cold cathode 'neon'tubes.
23. The decorative lamp of claim 18 or of any preceding claim wherein said lighting member produces light that is in the ultra-violet frequency of the electromagnetic spectrum.
24. The decorative lamp of claim 18 or of any preceding claim wherein the activation of said lighting member is controlled by a control circuit.
25. The decorative lamp of claim 24 or of any preceding claim wherein the lighting member is controlled so as to produce a strobe effect.
26. The decorative lamp of claim 24 or of any preceding claim wherein the lighting member is controlled so as to produce a scrolling text effect.