Claims:
1. A multi-pronged coil comprising of plurality of prongs which are terminally connected to each other at a terminal connection point.

2. The multi-pronged coil as claimed in Claim 1, wherein the multi-pronged coil has two prongs.

3. The multi-pronged coil as claimed in Claim 1, wherein the plurality of the prongs as burnt individually resulting in increased efficacy.

4. The multi-pronged coil as claimed in Claim 1, wherein the plurality of the prongs as burnt simultaneously increasing the emission of insecticide to reduce heavier insect load.

5. The multi-pronged coil as claimed in Claim 1, wherein the prongs of the coil have a variable thickness either throughout the length of the coil or part thereof.

6. The multi-pronged coil as claimed in Claim 1, wherein both the prongs have same thickness through the length of the coil.

7. The multi-pronged coil as claimed in Claim 1, wherein the coil comprises of active in concentration range of 0.01 – 0.5%, wood flour in concentration range of 15 – 60%. The binders in range of 1 – 10%, non-ionic emulsifier in range of 0.1 – 0.5%, burning aids in range of 2 – 5% and preservatives in range of 0.1 – 0.3%.

8. The multi-pronged coil as claimed in Claim 7, wherein the active is a Pyrethroid.

9. The multi-pronged coil as claimed in Claim 7, wherein the binder is selected form Guar gum, Starch, or a combination thereof.

10. The multi-pronged coil as claimed in Claim 7, wherein the burning aid is selected from sodium nitrate and potassium nitrate.

11. The multi-pronged coil as claimed in Claim 7, wherein the preservative is sodium benzoate.

12. The multi-pronged coil as claimed in Claim 1, is manufactured by a process comprising:
a. adding actives, perfume with potassium nitrate and emulsifier to water and stirring the mixture to get liquid premix;
b. mixing sawdust, charcoal, wood flour and the binders in a sigma mixer to obtain a dry mix;
c. adding the liquid premix of step (a) slowly to the dry mix of step (b) by means of a sigma mixer;
d. extruding the mixture of Step (c) as ribbon, by using ribbon extruder;
e. punching the ribbon of step (d) by using shape moulds, and
f. drying the ribbons of step (e) on a conveyer until the coil moisture level reaches to less than 10%.

13. A kit containing the at least two flash coil and a coil stand.
, Description:Field of Invention:
The current invention is in field of coil for vaporisation of insecticide. More particularly, the current invention relates to a mosquito repellent coil which can be burnt in dual modes and has plurality of prongs.

Background of the Invention:
Mosquitoes pose a great threat to a general well-being of the society. Mostly due to the reason that they act as vector for numerous diseases, some life-threatening and other which dispose a person for a long-time.

Most common diseases spread by this vector are malaria, which is very common in India. Other disease include, dengue, which is currently putting great burden on society and also on government, by disposing the working population and putting a strain on already thin-spread medical system. Other diseases which may be spread through mosquitos may include Chikungunya, Zika fever, Japanese Encephalitis, etc.

One of most effective way to stay safe is to avoid these infections by maintaining general hygiene. However, this is not always possible, especially when the residences as situated in a high population density region like squatments or refugee camps.
Further, the populace staying in these settlements are economically weak; hence, at times they may not be able to afford modern electronic mosquito repellents. In which case, the affordable option available to them is mosquito coils.

Mosquito coils have been around since long time, the earliest disclosure of mosquito coils could be found in US3248287, which was granted in 1966. One more disclosure could be found in US4144318. Currently, commercially available coil were probably disclosed in US5447713. Since these patents, various incremental improvements have been taking place over the years. However, these coils are generally single prong coils,

However, generally the single pronged coils do not have a quick efficacy whenever required. Generally, coils are burnt at night, the 8hr life, would leave the inhabitants exposed to attacks by mosquitos which are active in day time, such as A. aegypti which causes dengue.

Further, the coils currently in market are, generally, single uniform release coils, that is, the coil burns at a constant speed releasing the active uniformly as the coil burns, discounting the imperfections in the dispersion of the active while manufacturing. However, there are certain designs available in market which tends to have a specific shape, such as, bulged corners, whereby, the bulges are strategically placed so that a higher amount of active is emitted periodically throughout the burning life of the coil, as disclosed in 238/CHENP/2003.
Another case of designed release mosquito coils is disclosed in WO/2004/002222, whereby the coil disperses an initial burst of a high concentration of insect active ingredient into the environment to provide a fast acting initial dose. However, the coil would, still, have a burn time of not more than 8hours and the user would not have an option of choosing better and quicker efficacy in case of high infestation.

Therefore, in either cases of the prior art the coil would have a limited burn time of not more than 8 hours and do not have an option of choosing low or high efficacy mode based on infestation.

Further, as the coil burns at a constant speed, the emission of insecticide is uniform. The uniformity of the release might, at times, not prove enough to repel the mosquitoes, especially during rainy season which is the mosquito breeding season.

Therefore, in view of above mentioned problems, the current inventors strive to propose a novel mosquito coil which could solve the hereinbefore mentioned problems.

Objects of the invention:
Therefore, in view of above it is an object of the invention to provide, a coil which is designed to emit a higher amount of insecticide when required.

It is another object of the invention to provide a mosquito coil which has a provides faster and better efficacy.

Summary of the Invention:
In view of above objects, the present invention provides, in an aspect, a mosquito coil which is multi-pronged.

In another aspect, the invention provides a mosquito coil which can be burnt in a high power mode, whereby the multitude of the prongs of the coil, optionally with varying thickness is burnt simultaneously.

In yet another aspect, the invention provides a process for manufacturing the mosquito coil of the invention.

Brief Description of the Drawings:
Fig 1 illustrates the flash coil of the invention in accordance with one of the embodiments.

Fig. 2 illustrates the flash coil of the invention in accordance with another embodiment of the invention.

Fig. 3 illustrates the double coil pack of the coil as illustrated in Fig. 2.

Fig. 4 illustrates the actual photo of the flash coil in accordance with this invention.

Detailed Description of the Drawings:
As illustrated in Figs. 1, 2 and 3 the Flash Coil of the invention comprises of a terminal connection point (13) which serves as a common meeting point for the multitude of first prong 11 and successive prong 12.

In normal mode the user would ignite one of the prongs, preferably prong 11 which will burn till the terminal connection point 13 and the coil will continue to burn through prong 12 till the end of the coil.

In flash mode, the user would ignite both the prongs 11, 12 simultaneously which will burn till terminal connection point 13.

As illustrated in Fig. 1, the prongs 11 and 12 are of variable thickness either throughout the length of the coil or a part thereof.

The Fig. 2 illustrates another embodiment of the invention, whereby the prongs 11 and 12 of the coil are of the same thickness throughout the length of the coil.

In an embodiment, the flash coil of the invention can comprise more than one successive prongs 12.

Detailed Description of the Invention:
Described herein is a mosquito coil which has an improved burning time and demonstrates improved efficacy and ease of usage as per customer requirement, whereby the coil exhibits activity from 8 – 12 hours. Further, the mosquito coil of the invention can be burnt in a “flash mode”, whereby the amount of insecticide emitted in the environment is increased.

In an embodiment, the invention provides a multi-pronged mosquito coil, whereby each of the prongs can be burnt individually or can be burnt together, depending on the amount required to be emitted in the environment.

In accordance with above embodiment, the body of the coil is split in plurality of prongs which are terminally connected to each other at a terminal connection point. Preferably, the number of prongs is at least two. For the purpose of the specification, the multi-pronged coil of the invention is termed as “Flash coil”.

The multitude of the prongs, in accordance with this embodiment, burn exclusive to each other, that is, one burning prong does not ignite the next prong spontaneously. This exclusive burning of the single prong of the coil is termed as “Normal Mode”.

In normal mode, the insecticide emitted is comparable to the amount of insecticide emitted by burning of normal single-pronged coil available in market. However, the burning time of coil in normal mode would be around 8 – 12 hours, for a two pronged coil, depending on the length of the coil. The burn time may be modified to any suitable amount by suitably increasing the number of prongs and rings of coil.

While in normal mode, the first prong burns till terminal connection point (13), from the terminal connection point the successive prong will continue to burn in opposite direction.

In further accordance with the above embodiment, the coil could also be burned in a “Flash mode”, whereby all the prongs of the coil are ignited simultaneously. As all the prongs are ignited simultaneously, the insecticide incorporated in all the prongs would be emitted simultaneously in the environment, consequently, increasing the amount of insecticide in the environment. This increases the overall amount of insecticide emitted in the environment, which is effective in reducing the heavier insect load.

In flash mode, all the prongs burn till the terminal connection point simultaneously. The burn time of the coil is comparable to the burn time of the normal coil available in market, typically 6 – 8 hours and 10-12 hours depending on coil length. However, the amount of insecticide emitted while burning the coil in “flash mode” would be product of the number of prongs and the insecticide present in single prong. Preferably, the amount emitted in environment is twice that of the amount of insecticide emitted by normal coil available in market.

In a preferred embodiment, the coil of the invention has a physical structure as illustrated in Figs. 1 and 2. The coil of the invention comprises of at least two prongs, namely, a first prong 11 and a successive prong 12. Both the prongs 11 and 12 are seamlessly joined to each other at a terminal connection point 13. As stated hereinbefore, the coil could be burnt in two modes namely “Normal Mode” and “Flash Mode”. In “normal mode” the efficacy of the coil is equivalent to the efficacy of regular coil available in market, while in “flash mode”, the coil exhibits an increased efficacy in reducing the overall insect load.

In accordance with above embodiment, in “normal mode” the user ignites the first prong 11 and the prong 11 continues to burn till the terminal connection point 13, from where coil continues to burn through successive prong 12.

In “Flash mode” the user ignites both the prongs 11 and 12. The prongs 11 and 12 continue to burn simultaneously till the terminal connection point 13. In “flash mode” the coil exhibits an increased efficacy there by reducing heavier insect load.

In accordance with one of the embodiments, the prongs of the coil can have a variable thickness either throughout the length of the coil or part thereof. Alternatively, both the prongs can be of same thickness through the length of the coil.

In accordance with another embodiment, the flash coil of the invention can have multiple successive prongs (12) all joined seamlessly at the terminal connection point (13).

In another embodiment, the invention provides a composition for the coil of the invention. Said coil comprises of actives, wood flour, binders, non-ionic emulsifiers and preservatives, as required.

Typically, the active is selected from Pyrethroids. The binders are selected from Guar gum and Starch,. The coil may further contain burning aids selected from sodium nitrate and potassium nitrate and a preservative such as, sodium benzoate. In accordance with the above embodiment, the coil of the invention may optionally contain charcoal powder in range of 0 – 60%.

In accordance with the above embodiment, the active is in concentration range of 0.01 – 0.5%, wood flour is in concentration range of 15 – 60%. The binders are present in range of 1 – 10%, non-ionic emulsifier is present in range of 0.1 – 0.5%, potassium nitrate in range of 2 – 5% and preservatives in range of 0.1 – 0.3%.

In yet another embodiment the present invention provides a process for manufacturing the coil of the invention. The process of manufacturing the coil comprises of adding actives, perfume with potassium nitrate and emulsifier to water. Stirring said mixture for 30 min at 90 °C to get a liquid premix. A dry mix is formed by mixing sawdust, charcoal, wood flour and the binders in a sigma mixer at 25 RPM for 15 min. Adding the liquid premix slowly to the dry mix by means of a sigma mixer and extruding said mixture as ribbon by using ribbon extruder. Finally, punching the ribbon by using shape moulds and is dried in a conveyer at 60 – 70°C until the coil moisture level reaches to less than 10%.

In an embodiment, the flash coil of the invention is marketed as a kit containing the at least two coil and a coil stand.

EXAMPLE
Several examples are set forth below to further illustrate the nature of the invention and the manner of carrying it out. However, the invention should not be considered as being limited to the details thereof.

EXAMPLE 1:
Table 1: illustrates the proposed composition for the flash coil of the invention:
Ingredient Composition
Wood flour 15 – 60%
Charcoal powder 0 – 60%
Binders:
Guar gum 1 – 3 %
Starch 0 – 5%
Clay dust 0 – 10%
Calcite dust 0 – 10%
Non-ionic emulsifier 0.1 – 0.5%
Potassium nitrate 2 – 5%
Active ingredient:
Pyrethroids 0.01 – 0.5%
Preservative:
Sodium Benzoate 0.1 – 0.3%

Process for manufacturing the Flash coil of the invention:
a. adding actives, perfume with potassium nitrate and emulsifier to water and stirring the mixture for 30 min at 90 degrees centigrade to get liquid premix;
b. mixing sawdust, charcoal, wood flour and the binders in a sigma mixer at 25 RPM for 15 min to obtain a dry mix;
c. adding the liquid premix of step (a) slowly to the dry mix of step (b) by means of a sigma mixer;
d. extruding the mixture of Step (c) as ribbon, by using ribbon extruder;
e. punching the ribbon of step (d) by using shape moulds, and
f. drying the ribbons of step (e) on a conveyer at 60 – 70 degrees centigrade until the coil moisture level reaches to less than 10%.

EXAMPLE 2:
Comparative Data:
Table 2: the below table illustrates the comparative data of the burning time for a coil having a standard coil length.
Parameters Existing Single Prong Coil Flash coil of the invention
Coil Length (cm) 70 -72 70 -72
Coil Weight (g) 24 24
Coil Diameter (mm) 120 120
Burn Time (hr) upto 08 upto 8.0- – NM
3.0-3.5 - FM

Table 3: the below table illustrates the comparative data of the coils having longer length.
Parameters Existing Single Prong Coil Flash coil of the invention
Coil Length (cm) 105 105
Coil Weight (g) 34 34
Coil Diameter (mm) 146 146
Burn Time (hr) –upto 12.0 –upto 12.0 NM
5.5 -6.0 FM

EXAMPLE 3:
Table 4: the below table illustrates the comparative efficacy data of the coils currently available in market sold under brand name Good Knight Mahajumbo 12 hour Coil (a product marketed by the Applicant).
ETOC 0.04% coil Active Released KT50 Minutes KT95 Minutes % KD 60 minutes Mortality %
Mahajumbo Coil
1.2 mg 50-60 100+ 40-50 5-10
Flash Coil – Flash mode 2.4 mg 25 - 35 55-70 80 NA
Flash Coil – Normal mode 1.2 mg 50-60 100+ 40-50 5-10