THE PATENT ACT. 1970 COMPLETE
SPECIFICATION
SECTION 10
TITLE
"A process for producing permanent marking on the surface of an aluminium article.
APPLICANT
HAWKINS COOKERS LIMITED, MAKER TOWER , F-101, CUFFE PARADE, P.O. BOX-16083, MUMBAI- 400 005,. An Indian Company.
The following specification particularly describes the invention and the manner in which it is to be performed.
1035-MUM-2004
26 MAY 2008

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FIELD OF INVENTION
This invention relates to a process for producing permanent marking on the surface of an aluminium article such as pressure cooker having an anodized surface only in selected areas or locations of the pressure cooker.
BACKGROUND OF INVENTION
To have a pressure cooker with a base having a hard anodized surface including a portion of the side wall is known in the art. As the base and the lower side of the side wall is subjected to maximum thermal stresses, the provision of such a hard anodized surface does improve the working properties of the pressure cooker. However, such an anodized surface was provided along the entire lower side of the sidewall, and not only along a selected area.
Further, in the known pressure cookers;galvanic corrosion takes place between the stainless steel vent tube and the aluminium handle bar after years of usage Galvanic corrosion is a phenomenon that takes place between two dissimilar metals in the presence of an electrolyte. In the

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instance of pressure cookers, water is accumulated between the handle bar and the vent tube due to washing etc. or even due to condensed steam coming out of the vent weight.
OBJECT OF THE INVENTION
An' object of this invention is to provide a process for producing permanent marking on the surface of an aluminum article.
Another object of this invention is to provide a process.for producing permanent marking on the surface of an aluminum article having an anodized surface only in selected areas.
Still another object of this invention is to provide a process for producing permanent marking on the-surface of an aluminium article having an anodized surface only in selected areas and wherein galvanic corrosion no longer takes place between the stainless steel vent tube and the aluminium handle bar.
Yet another object of this invention is to propose a process for producing permanent marking on the surface of an aluminium article having an anodized surface only in selected areas of the lower end of the side wall of the pressure cooker.
Further objects and advantages of this invention will be more apparent from the ensuing description.

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STATEMENT OF INVENTION
According to this invention there is provided a process for producing permanent marking on the surface of an Aluminium article such as pressure cooker comprising steps of applying masking tapes to a predetermined area of said surface, anodizing selected area of the surface having said masking tapes of polyvinyl chloride or Biaxially oriented poly propylene and anodizing tip of the handle bar.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Further, objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein:

Fig. 1 Fig. 2 Fig. 3

shows side view of the cooker.
shows bottom perspective view of the cooker.
shows top perspective view of the cooker.

2 4 JUL 2008

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DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO ACCOMPANYING DRAWINGS:
In accordance with this invention and referring to figure 1, the lower end (1) of the sidewall (2) of the pressure cooker (3) has an anodized surface only in selected areas. The selected area provides for a lettering, such as DOUBLE THICK BASE, on the anodized surface. The lettering is achieved by sticking suitable masking/tapes corresponding to the letters on the cooker body before dipping the cooker body in the anodizing bath. Due to the masking tapes applied on the cooker body, those portions of the cooker body do not get anodized. Thus, the letters are nothing but the bare aluminium of the cooker body since they do not get anodized due to the masking tapes, the letters are therefore, permanent unlike printed letters which can get wiped off with little use.
Now reference may be made to figure 3, wherein the tip (4) of the Aluminium handle bar (5) is anodized. The anodized tip is created by the process of partial anodizing of the handle bars in which only the tip of the handle bar is dipped in the anodizing bath. In this process, the line demarcation between the anodizing and the non anodizing zone in the handle bar is

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created by putting a masking tape beyond the anodizing zone and extending the tape beyond the anodizing bath. The purpose of anodizing the handle bar tip is to give a more durable handle bar.
For the composition of anodizing bath and process for the partial anodizing/anodizing, reference may be made to the previous Application for "A process of partial anodizing of the cooker" in the name of same Applicant.
It is to be understood that the present invention is susceptible to modification, changes, adaptations by those skilled in the art. Such modifications, changes adaptations are intended to be within the scope of the present invention, which is further set forth under the following claims:

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WE CLAIM;
1. A process for producing permanent marking on the surface of
an Aluminium article such as pressure cooker comprising steps
of:
applying masking tapes to a predetermined area of said surface, anodizing selected area of the surface having said masking tapes of polyvinyl chloride or Biaxially oriented poly propylene and anodizing tip of the handle bar.
2. A process as claimed in claim l, wherein the masking tapes are corresponding to a marking such as letters.
3. A process for producing permanent masking on the surface of an Aluminium article such as pressure cooker substantially as herein described.
Dated this 27th day of September, 2004

(SOMA RANI MISHRA) OF L.S.DAVAR&CO., APPLICANT'S AGENT