DESC:[001] PRIORITY CLAIM
[002] This application claims priority from the provisional application number: 1727/CHE/2013 filed with Indian patent Office, Chennai on 18th April, 2013 entitled “Automated system with auxiliary cathode(s) and internal surface jet cooling system(s) for hard anodizing of articles of aluminum of non uniform/odd shapes and angles with restricted or unrestricted opening(s)”, the entirety of which is expressly incorporated herein by reference.
[003] PREAMBLE TO THE DESCRIPTION
[0001] The following specification particularly describes the invention and the manner in which it is to be performed:
[004] FIELD OF THE INVENTION
[005] The invention relates to an automated system with auxiliary cathode(s) and internal surface jet cooling system(s) for hard anodizing of articles of aluminum of non uniform/odd shapes and angles with restricted or unrestricted opening(s).
[006] BACKGROUND
[007] Hard anodized cookware is a fast moving product in the culinary world. There are several reasons for the increased usage of hard-anodized cookware by the people; one amongst them is the durability and long lifespan of the hard anodized cookware. Hard anodized cookware resists scratches, warping, and corrosion. Hard anodizing is the formation of a hard oxide layer on the surface of aluminum. These hard anodized cookwares come in many shapes such as cylindrical shapes with restricted opening(s) and non cylindrical shapes with restricted or unrestricted opening(s) with angles.

[008] Also the hard anodized cookware which is having a core of aluminum is also known for its even heat distribution, which means that hard anodized cookware may also produce uniform results, irrespective of the matter which is being prepared on a continuous basis.

[009] Anodizing aluminum cookware results in a hard layer (measured in microns) formation on the surface, which is highly durable in comparison to normal cookware. The hard anodized cookware is resistant to high temperature and remains stain-free. Anodising is an electrochemical process for producing protective films on articles made from aluminium and its alloys. Anodising is an electrochemical process where a film of aluminium oxide is built up on the surface of the aluminium through the use of a different type of electrical current, that may be direct current (DC), alternating current (AC) superimposed on DC, Pulse AC and AC. Normally, during sulphuric acid anodizing process for cookware at low temperatures, DC is used. During anodizing process, the anodized aluminum layer is grown by passing a direct current through an electrolytic solution with the aluminum object serving as the anode (the positive electrode). The current releases hydrogen at the cathode (the negative electrode) and oxygen at the surface of the aluminum anode, creating a build-up of aluminum oxide. The voltage required by various solutions may range from 1 to 300 V DC although most fall in the range of 15 to 21 V. Higher voltages are typically required for thicker coatings formed in sulfuric acid. The anodizing current varies with the area of aluminum being anodized and typically ranges from 30 to 300 amperes /meter² (2.8 to28 ampere/ft²). Aluminum anodizing is usually performed in an acid solution. The acid action is balanced with the oxidation rate to form a coating with nano pores which is 10-150 nm in diameter.
[010] As the demand for anodized cookware increases, there is a need to look for automated system for anodizing the cookware. But the automated system so employed for anodizing the cookware should drain off the liquid completely when the cookware is taken out from the electrolytic bath, so that the consequent electrolytic baths are not contaminated or diluted. Also, there exists a need to maintain the thickness of the oxide layer uniformly throughout the cookware.

[011] The US patent publication no US2010320079A1 (referred as ‘079’) discloses an anodizing system that is used in anodizing production parts. The anodizing system includes an anodizing monitoring device that is arranged in parallel in an electrical circuit with one or more production parts to be anodized. The anodizing monitoring device includes an amp meter that may be monitored by an operator. The operator may apply voltage to the electrical circuit to cause anodizing of the production parts and monitor the amp meter until a desired amount of amperage is achieved. Electrical energy may continue to be applied until a desired coating of the production parts is reached. Constant current may thus be applied in the anodizing process without the need to calculate the area of the production parts being treated. But ‘079’ does not disclose about a system or a process for completely eliminating the contamination of solutions from one stage by the preceding stage.
[012] Although various anodizing process have been developed in the industries, the process still encounters many difficulties if care is not taken to ensure that solutions are controlled with regard to concentration and temperature. Thorough rinsing of the component is carried out after each stage to ensure that it enters the next process in the correct state. It also ensures that contamination of solutions from one stage by the preceding stage is kept to a minimum. A further aspect not covered herein is that of quality control. Even in small plants, chemists are employed to constantly check the conditions of the solutions and make recommendations/adjustments. In addition, frequent checks are made on the thickness of the film, its density and the colour quality.

[013] Pan or outer lid cookware are anodized by dipping them into bath of electrolytes such as sulfuric acid and then running an electrical current through the bath. The process forms an oxide coating on the aluminium, wherein the oxide coating shields the aluminium based article from corrosion and increases its wear resistance properties thereby eliminating leaching. Once the cookware is anodized, it is removed from the electrolyte bath ensuring that the entire electrolyte is drained, wherein in the existing anodizing system this process is performed manually by handling each cooker separately. However, anodizing articles/cookware of cylindrical shapes with restricted opening(s) and non cylindrical shapes with restricted or unrestricted opening(s) is an issue as the cookware (article) has to be dipped inside an electrolytic bath, ensuring that no air is entrapped and the cookware has to be removed ensuring the entire electrolyte is drained off. Apart from this, maintaining uniform oxide layer thickness throughout the article/cookware is difficult.

[014] Hence, there is a need of an improved automated system for anodizing of the articles of cylindrical shapes with restricted opening(s) and non cylindrical shapes with restricted or unrestricted opening(s) in a controlled and effective manner, so as to ensure that the entire electrolyte is drained off and the subsequent baths are not contaminated. There also exists a need to ensure that the oxide layer formed throughout the article is uniform regardless of the shape of the article.

[015] SUMMARY OF THE INVENTION
[016] The present invention overcomes the drawback of prior art by providing an automated system for hard anodizing of the articles. For this purpose, the system comprises a fixture on which one or more articles to be anodized is fitted, wherein the fixture is configured to hold the article and rotate the article when article is being immersed or being removed from the anodizing electrolytic bath. The fixture further comprises rollers fitted on the rotating part of the fixture and a counter weight fitted only on the moving portion of the fixture. The system of the present invention also comprises a linear actuator, wherein the linear actuator is provided with a linear actuating piston inside a static cylinder. The linear actuating piston is moved up and down by an electric drive so as to rotate the fixture. Here, the free end of the linear actuating piston has a plate fitted on which the roller of the rotating part of the fixture rolls when the roller comes in contact with the plate of the linear actuating piston. Also the counter weight is fitted only on the moving portion of the fixture such that the counter weight comes up when the fixture is rotated by the rollers. This makes the counter weight to be above the center of gravity of the fixture. Once the counter weight’s center moves away from the vertical axis of the center of gravity of the moving part of the fixture, the counter weight rotates the fixture in the direction based on which side the counter weight is of the vertical axis of the fixture. A stopper is provided on the fixture so as to stop further movement of the fixture when the horizontal axis of the center of gravity of the counter weight and the fixture coincide.
[017] In accordance to one or more embodiment of the present invention, the article may be of any cylindrical shape with restricted opening or the article may be of any non cylindrical shape with restricted or unrestricted opening. Furthermore, the system of the present invention effectively anodises the article. The system of the present invention comprises an auxiliary cathode to be placed on the inner lid of each article on the fixture to be anodized, so as to provide uniform thickness of oxide layer throughout the article. The system of the present invention also comprises an internal surface jet cooling system for each article on the fixture to be anodized, so as to remove excess heat produced during the anodising or oxide forming process.

[018] BRIEF DESCRIPTION OF FIGURES
[019] In order that the invention be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with a detailed description below are incorporated in and form part of the specification which serve to further illustrate the embodiments, explain various principles and advantages, in accordance with the present invention.
[020] FIG 1, FIG 1a and FIG 1b illustrates the schematic view of an automated system for hard anodizing of the articles in accordance to one or more embodiment of the present invention.
[021] FIG 2 illustrates the view of the auxiliary cathode in accordance to one or more embodiment of the present invention.
[022] FIG 3 illustrates the view of the internal surface jet cooling system in accordance to one or more embodiment of the present invention.

[023] FIG 4 illustrates the perspective view of the automated hard anodizing plant assembly in accordance to one or more embodiment of the present invention.

[024] DETAILED DESCRIPTION OF THE INVENTION
[025] Unless otherwise defined, all technical and scientific terms used herein have the meaning commonly understood by a person skilled in the art to which this invention belongs. One skilled in the art will recognize many systems similar or equivalent to those described herein, which could be used in the practice of this invention. Indeed, this invention is in no way limited to the system described.
[026] The term ‘article’ used herein refers to any utensil such as a cookware, wherein the article is of any cylindrical shape with restricted opening. The article may also be of any non cylindrical shape with restricted/unrestricted opening.
[027] FIG 1, FIG 1a and FIG 1b illustrates the schematic view of an automated system for hard anodizing of articles in accordance to one or more embodiment of the present invention. The automated system for hard anodizing of articles comprises actuators (101), fixtures (103), rollers (102) and counter weight (104). The automated system for hard anodizing of articles (100) comprises a fixture (103) on which one or more articles (105) to be anodized is fitted, wherein the fixture (103) is configured to hold the article (105) and rotate the article (105) when the article (105) is being immersed or being removed from the anodizing electrolytic bath during the electrolytic process. The fixture (103) further comprises rollers (102) fitted on the rotating part of the fixture (103) and a counter weight (104) fitted only on the moving portion of the fixture (103). The positive side of the current is connected to the fixture (103) so that the current flows to the article (105) during the anodizing process. The automated system for hard anodizing of articles (100) of the present invention also comprises a linear actuator (101), wherein the linear actuator (101) is provided with a linear actuating piston inside a static cylinder. The linear actuating piston is moved up and down by an electric drive so as to rotate the fixture (103). Here the free end of the linear actuating piston has a plate fitted on which the roller (102) of the rotating part of the fixture (103) rolls when the roller (102) comes in contact with the plate of the linear actuating piston. Also the roller (102) is fitted on the rotating part of the fixture (103) and the roller (102) enables contact of the tilting fixture (103) on to the linear actuating plate at different angles (as shown in FIG 1a).
[028] In accordance to one or more embodiment of the present invention, the counter weight (104) is fitted only on the moving portion of the fixture (103) so that the counter weight (104) comes up when the fixture (103) is rotated by the rollers (102). This makes the counter weight (104) to be above the center of gravity of the moving part of fixture (103). Once the counter weight’s (104) center moves away from the vertical axis of the center of gravity of the moving part of the fixture (103), the counter weight (104) rotates the fixture (103) in the direction based on which side the counter weight (104) is of the vertical axis of the fixture (103). A stopper is provided on the fixture (103) so as to stop further movement of the fixture (103) when the horizontal axis of the center of gravity of the counter weight (104) and the fixture (103) coincides (as shown in FIG 1b). Thus, the fixture (103) completely drains off the electrolyte when the article (105) is brought out from the anodizing electrolytic bath. Thereby, the automated system for hard anodizing of articles (100) of the present invention eliminates contamination of solutions from one stage by the preceding stage.
[029] In accordance to one or more embodiment of the present invention, the article (105) may be of any cylindrical shape with restricted opening. The article (105) may also be of any non cylindrical shape with restricted/unrestricted opening.
[030] FIG 2 illustrates the view of the auxiliary cathode in accordance to one or more embodiment of the present invention. The automated system for hard anodizing of articles (100) comprises an auxiliary cathode (201) to be placed on the inner lid of each article (105) on the fixture (103) to be anodized so as to provide uniform thickness of oxide layer throughout the article (such as inner lid and outer lid portion of the article). The auxiliary cathode (201) placed on the inner lid of the each article (cookware) (105) to be anodized is also capable of providing uniform thickness of oxide layer to articles having restricted opening (inlet).
[031] FIG 3 illustrates the view of the internal surface jet cooling system in accordance to one or more embodiment of the present invention. The automated system for hard anodizing of articles (100) of the present invention also comprises an internal surface jet cooling system (301) for each article (105) on the fixture (103) to be anodized so as to remove the excess heat produced during the hard anodizing process by using normal agitation process for the removal of heat from the surface of the article.
[032] FIG 4 illustrates the perspective view of the automated hard anodizing plant assembly in accordance to one or more embodiment of the present invention. The automated hard anodizing plant assembly (400) of the present invention comprises a stand, a frame (401) placed on the top of the automated hard anodizing plant assembly (400), a linear actuator (101) comprises an actuating piston placed inside a static cylinder wherein the piston is moved up and down by an electric drive. The automated hard anodizing plant assembly (400) also comprises rollers (102) so as to move the frame (401) uniformly in a vertical direction. The automated hard anodizing plant assembly (400) also comprises a fixture (103) (which is part of the frame (401)) to hold the one or more articles (105) to be anodized, wherein the frame (401) along with fixture (103) moves up and down and hold the article (105) to be immersed into the anodizing electrolytic tank (402). Furthermore, each individual article (105) on the fixture (103) is provided with an auxiliary cathode (201) so as to provide uniform anodizing thickness of oxide layer throughout the article (105). As the anodizing current varies with the area of aluminum being anodized, a transformer (403) is also used for providing the required voltage to the automated hard anodization plant assembly (400).
[033] The automated system for hard anodizing of the articles is capable of providing a hardcoat over the article with thickness of above 25 µm (1 mil) so as to increase the wear resistance and corrosion resistance of the article. The hardcoat formed over the article of the present invention has good resistance against pitting, galvanic and general corrosion. Hardness is about 65- 70 Rockwell C to 850- 900 DPH. The color of the coating varies from dark gray to black. Dielectric films formed are non-conductive and will withstand 800 volts per 30 micrometers. Coating thickness is up to 25-150 micrometers. Resistivity of the hardcoat is between 106 - 1012 Ohm-cm and the hardcoat may be Dichromate, Ni-Acetate or hot water sealed.
[001] Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of the components within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Bindu Sharma
Regd. Patent Agent
IN/PA 1055
April 16, 2014

[002] Claims
[003] We claim:
1. An automated system for hard anodizing of articles (100) comprises:
a) a fixture (103) on which one or more articles (105) to be anodized is fitted, wherein the fixture (103) is configured to hold the article (105) and rotate the article (105) when the article (105) is being immersed or being removed from the anodizing electrolytic bath, wherein the fixture (103) further comprises:
- rollers (102) fitted on the rotating part of the fixture (103);
- a counter weight (104) fitted only on the moving portion of the fixture (103);
b) a linear actuator (101) provided with an actuating piston inside a static cylinder, wherein the free end of the linear actuating piston has a plate fitted on which the roller (102) of the rotating part of the fixture (103) rolls when the roller (102) is in contact with the plate of the linear actuating piston; and
c) an auxiliary cathode (201) to be placed on the inner lid of each article (105) on the fixture (103) to be anodized so as to provide uniform thickness of oxide layer throughout the article (105).
2. The automated system for hard anodizing of articles (100) as claimed in claim 1, wherein the roller (102) enables contact of the tilting fixture (103) on to the linear actuating plate at different angles.
3. The automated system for hard anodizing of articles (100) as claimed in claim 1, wherein the counter weight (104) is fitted only on the moving portion of the fixture (103) so that the counter weight (104) comes up when the fixture (103) is rotated by the rollers (102).
4. The automated system for hard anodizing of articles (100) as claimed in claim 3, wherein when the counter weight’s (104) center moves away from the vertical axis of the center of gravity of the moving part of the fixture (103), the counter weight (104) rotates the fixture (103) in the direction based on which side the counter weight (104) is of the vertical axis of the fixture (103).
5. The automated system for hard anodizing of articles (100) as claimed in claim 4, wherein a stopper is provided on the fixture (103) so as to stop further movement of the fixture (103) when the horizontal axis of the center of gravity of the counter weight (104) and the fixture (103) coincides.
6. The automated system for hard anodizing of articles (100) as claimed in claim 5, wherein the fixture (103) completely drains of the electrolyte when the article (105) is brought out from the anodizing electrolytic bath.
7. The automated system for hard anodizing of articles (100) as claimed in claim 1, wherein the system (100) further comprises an internal surface jet cooling system (301) for each article (105) on the fixture (103) to be anodized so as to remove excess heat produced during the hard anodizing process.
8. The automated system for hard anodizing of articles (100) as claimed in claim 1, wherein the article (105) is of any cylindrical shape with restricted opening.
9. The automated system (100) for hard anodizing of articles as claimed in claim 1, wherein the article (105) is of any non cylindrical shape with restricted/unrestricted opening.

Bindu Sharma
Regd. Patent Agent
IN/PA 1055
April 16, 2014

[004] Abstract
[005] The present invention relates to an automated system for hard anodizing of articles. The system of the present invention completely empties the electrolyte when the article is brought out from the anodizing electrolytic bath thereby eliminating contamination of solutions from one stage by the preceding stage in the anodizing process. Furthermore the system of the present invention also comprises an auxiliary cathode to be placed on the inner lid of each article to be anodized so as to provide uniform thickness of oxide layer throughout the article. The system also comprises an internal surface jet cooling system for each article to be anodized so as to remove excess heat produced during the hard anodizing process.

Bindu Sharma
Regd. Patent Agent
IN/PA 1055
April 16, 2014
,CLAIMS:[002] Claims
[003] We claim:
1. An automated system for hard anodizing of articles (100) comprises:
a) a fixture (103) on which one or more articles (105) to be anodized is fitted, wherein the fixture (103) is configured to hold the article (105) and rotate the article (105) when the article (105) is being immersed or being removed from the anodizing electrolytic bath, wherein the fixture (103) further comprises:
- rollers (102) fitted on the rotating part of the fixture (103);
- a counter weight (104) fitted only on the moving portion of the fixture (103);
b) a linear actuator (101) provided with an actuating piston inside a static cylinder, wherein the free end of the linear actuating piston has a plate fitted on which the roller (102) of the rotating part of the fixture (103) rolls when the roller (102) is in contact with the plate of the linear actuating piston; and
c) an auxiliary cathode (201) to be placed on the inner lid of each article (105) on the fixture (103) to be anodized so as to provide uniform thickness of oxide layer throughout the article (105).
2. The automated system for hard anodizing of articles (100) as claimed in claim 1, wherein the roller (102) enables contact of the tilting fixture (103) on to the linear actuating plate at different angles.
3. The automated system for hard anodizing of articles (100) as claimed in claim 1, wherein the counter weight (104) is fitted only on the moving portion of the fixture (103) so that the counter weight (104) comes up when the fixture (103) is rotated by the rollers (102).
4. The automated system for hard anodizing of articles (100) as claimed in claim 3, wherein when the counter weight’s (104) center moves away from the vertical axis of the center of gravity of the moving part of the fixture (103), the counter weight (104) rotates the fixture (103) in the direction based on which side the counter weight (104) is of the vertical axis of the fixture (103).
5. The automated system for hard anodizing of articles (100) as claimed in claim 4, wherein a stopper is provided on the fixture (103) so as to stop further movement of the fixture (103) when the horizontal axis of the center of gravity of the counter weight (104) and the fixture (103) coincides.
6. The automated system for hard anodizing of articles (100) as claimed in claim 5, wherein the fixture (103) completely drains of the electrolyte when the article (105) is brought out from the anodizing electrolytic bath.
7. The automated system for hard anodizing of articles (100) as claimed in claim 1, wherein the system (100) further comprises an internal surface jet cooling system (301) for each article (105) on the fixture (103) to be anodized so as to remove excess heat produced during the hard anodizing process.
8. The automated system for hard anodizing of articles (100) as claimed in claim 1, wherein the article (105) is of any cylindrical shape with restricted opening.
9. The automated system (100) for hard anodizing of articles as claimed in claim 1, wherein the article (105) is of any non cylindrical shape with restricted/unrestricted opening.