DTSi - The twin spark thing - What the patent says part 3

On searching for checking the novelty of the basic patent of DTSi we came across some interesting facts

1. Using two spark plugs in a single cylinder IC engine cannot be the novelty of the DTSi patent -Many patents filed before the filing of the basic patent of DTSi show this concept

US4920944 - IGNITION DEVICE FOR AN INTERNAL COMBUSTION ENGINE WITH TWO SPARK PLUGS PER CYLINDER
Filing date: 5 Jun 1989
Issue date: 1 May 1990
Inventors: Paolo Lanati, Alessandro Piccone, Domenico D'Angelo
Original Assignee: Alfa Lancia Industriale S.p.A.

The patent claims the novelty to be the arrangement of the spark plugs in a small engine. Also it claims that the sleeve is for protecting the spark plug from the lubricating liquid which will affect it if it is located where itts located near the timing chain

So the patent claims solving following problems:

1. Use of two spark plugs to imporve combustion
2. No need for a rich air fuel mixture - good efficiency in a lean air fuel mixture
3. Providing a sleeve which protects one of the spark plug from lubricating oil

The cavity in which the timing chain is located opens in the crankcase that is filled with oil for lubrication of moving parts. The chain while driving the driven sprocket carries oil with it for lubrication and if the opening for spark plug is provided in this cavity the lubricating oil spreads over the spark plug and affects its function.



Considering fitting of two spark plugs in a small engine and protecting the spark plug against lubricating oil as solving a technical contradiction, it would require the knowledge of the presence of oil in the cavity near the timing chain and also the knowledge that oil affects the spark plug

Hence we can classify the DTSi as a Level 2 Innovation in which a technical contradiction is solved by applying knowledge from various areas of the industry relevant to the system

DTSi - The twin spark thing - What the patent says part 2

Some things are crystal clear regarding the scope of the patent

1. It is for four stroke engines (Independent claim)
   
2. It is for lean air fuel mixture (Independent claim) - for more info on air fuel ratios read [1]
3. It is for small capacity engines ( although this is not directly claimed, claimed as used in two wheelers dependent claim)

Patents are written in legal technical language popularly called patentese.
This mixture of legal and technical makes it quite difficult to grasp for first timers and slightly boring too. I will try my best to present all the patent information with minimum use of patentese.


All claim elements:



Independent claim:

An improved Internal Combustion Engine for efficient burning of lean air fuel mixture used in engines working on four stroke principle, characterized in that said Internal Combustion Engine comprising

1. a pair of spark plugs
2. a cylinder head
3. a sleeve
4. a pair of sealing means,
5. a fixing means
6. sleeve cap

The pair of spark plugs are fitted to the cylinder head to ignite air fuel mixture at predetermined instant;

One of the spark plugs is housed within sleeve, and that sleeve is detachably fixed to cylinder head and held in position by said fixing means,

Sealing means are provided between the cylinder head and the outer periphery of the sleeve and the sleeve cap is fitted on to sleeve.

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Dependent claims:

The pair of spark plugs are fitted opposite preferably diametrically to each other

The fixing means is a circlip or a screw.

The pair of sealing means is an O ring or an oil seal.

The sleeve cap is made of resilient material such as Nylon, PVC, rubber.

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Independent claim:

An improved Internal Combustion working on four stroke principle, characterized in that said Internal Combustion Engines

comprising of

1. a spark plug
2. a cylinder head
3. a sleeve
4. a pair of sealing means
5. a fixing meanssleeve cap
   

The spark plug being housed within said sleeve and being fitted to a cylinder head on timing chain side so as to provide spark predetermined instant to ignite air fuel mixture

The sleeve detachably fixed to cylinder head and held in position by fixing means

The pair of sealing means are fitted between the cylinder head and the outer periphery of said sleeve and the said sleeve cap, made of resilient rial such as Nylon, PVC, rubber being fitted on cylinder head

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Dependent claim:

A single cylinder Internal Combustion Engine with improved combustion characteristics for use in two or three wheeled vehicles running on four stroke principle is described herein above and illustrated.

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References

[1] http://en.wikipedia.org/wiki/Air%E2%80%93fuel_ratio

DTSi - The twin spark thing - What the patent says

DTSi (Digital Twin Spark Ignition) - in laymen terms it is the word that is repeated (or rather was repeated) in all BAJAJ ads in the past years

It is a technology using two spark plugs in a engine (very simplistically speaking) you may find some very good information in [1] and [2].

There is a lot of information on this on the web, [3] and [4] will get you started

I would avoid going deep in the theory part and focus on what the patents say.

Patents are a very important tool, they can give you the insights in what went through the inventors mind when they worked on the technology and what is the invention level (as in TRIZ level) etc

In the related articles which will be updated soon:

• We will start by analysing the basic patent or the original patent for the DTSi technology. WO2005042954 [5] titled 'IMPROVED INTERNAL COMBUSTION ENGINE WORKING ON FOUR STROKE PRINCIPLE' (The basic patent of DTSi in reality is an Indian patent from which this patent takes priority, I havent found that patent yet so this one is the next best choice)

• In our analysis we will identify the claim elements and present them here in simple language
  
• We will try to identify its invention level as per TRIZ

References

[1] http://www.geekinterview.com/question_details/46250

[2] http://kedarparikh.blogspot.com/2007/12/what-is-dts-i-dts-si-and-dts-fi.html

[3] http://www.bajajauto.com/dis135_technology.asp

[4] http://www.business-standard.com/india/news/bajaj-autodts-i-technology/296701/

[5] http://worldwide.espacenet.com/publicationDetails/biblio?CC=WO&NR=2005042954A1&KC=A1&FT=D&ND=8&date=20050512&DB=worldwide.espacenet.com&locale=en_EP