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Pressure Cooker Design Invalidation Case
date: 2014-05-06


    Zhejiang Aishida Electric Co., Ltd., the owner of the design patent numbered ZL201130186505.9, accused Zhejiang Supor Co., Ltd. of violating its patent by selling electric pressure cookers on the market.

    We were asked to file a patent design invalidation process and suspend the infringement suit as soon as possible so as to help Zhejiang Supor Co., Ltd. to successfully defend itself.

    On 28 April 2012, we, acting as the attorney of Zhejiang Supor Co., Ltd., filed a request for invalidation of the design patent of Zhejiang Aishida Electric Co., Ltd. numbered ZL201130186505.9.


    After receiving the client's pressing requests, we realized that we must have the patent invalidation application be accepted as soon as possible, and thus requested the court to suspend the trial of the case. We then hired some experienced design examiners to conduct professional research, and organized in-house personnel to discuss the patent in question. 

    The patent in question was filed in 2011, and thus is governed by the Patent Law as amended in 2009. The patentability of design patents can be evaluated by comparing a combination of documents. Based on the documents provided by the client and the research results, we first chose a design that was closest to the patent in question in terms of overall appearance, parts and shape of each part as Comparable Design 1, and then compared such Comparable Design with the patent in question to distinguish them, including the shape of the pressure limiting valve, step-like design of the edge of the cover, as well as the concave-convex alternative design on the rim of the cover. Afterwards, we managed to make Comparable Design 2 and Comparable Design 3 available based on the report on the evaluation of the appearance of the patent in question and the references provided by the client, and came to the conclusion that there was no obvious distinction between the design of the pressure cooker for which we had substituted the pressure limiting valve, the step-like design of the edge of the cover, and the concave-convex alternative design on the rim of the cover with that of Comparable Design 1 and the patent in question. Therefore, we claimed that the patent in question had failed to comply with Article 23 (2) of the Patent Law, and should be declared invalid.

    We were informed that the client was collecting relevant evidence on the public use of the products, which might take some time. Upon analysis, we decided to file the invalidation request with three sets of patent literature as the comparable documents, and then submit evidence on the public use as supplementary opinions within the one-month extended period. In this way, we could promptly receive the invalidation acceptance notice and then file an application for suspension of the litigation. Indeed, we managed to set aside time for the collection of supplementary evidence.

    With the consent of the client, we received the acceptance notice by using the expedited process for requesting a patent invalidation declaration, and promptly forwarded the same to the client. Within the one-month period for supplementary evidence to be filed, the client provided evidence of the records of the sale of YW22N1 pressure cookers prior to the application date of the patent in question, as well as images of the relevant products, in regard to which the client had conducted web notarization as Comparable Design 4. The client had also collected the sales receipts from its distributors as evidence 5 and for supporting the fact of the sale of YW22N1 pressure cookers. In addition, the client provided the promotional material from Carrefour and other distribution points, which was printed with the image of "YW22N1" pressure cookers, and promotion dates, all prior to the application date of the patent in question, as Comparable Design 6.

    By presenting the above-mentioned evidence for public use, as well as Comparable Design 4, or a combination of Comparable Design 4 and Evidence 5, or Comparable Design 6 alone, we managed to prove that the patent in question had failed to comply with the provisions of Article 23(1) of the Patent Law. Then, we evaluated the patentability of the patent in question by combining Comparable Design 4 and Comparable Design 3, or combining Comparable Designs 4, 5 and 3, or combining Comparable Design 6 and Comparable Design 3 and on the basis of the provisions of Article 23(2) of the Patent Law.

    The Patent Reexamination Board of the State Intellectual Property Office finally adopted the combination of Comparable Design 4 and Comparable Design 3, and declared the patent in question fully invalid on the ground that it lacked obvious distinction.

Key points in the proceedings of the case

    Is there any inspiration from the combination of Comparable Designs?

    Above the cover of the cooker in Comparable Design 1 is a pressure limiting valve, which is different from the patent in question only in shape, but the shape of the pressure limiting valve in Comparable Design 2 is similar to that of the patent in question, and Comparable Design 1 gave a hint as to the installation of pressure limiting valves on cooker covers. The edge of the cover in Comparable Design 3 is step-like, and the rim does not have a concave-convex alternative design. Therefore, it is possible to replace the design of the cover in Comparable Design 1 with the step-like and no concave-convex alternative design in Comparable Design 3. In such case, the pressure cooker from a combination of Comparable Designs 1, 2 and 3 is basically the same as in the patent in question in terms of the overall appearance, various parts and the shape of each part, even though there is a little subtle difference, and is thus insufficient to have a remarkable impact on the overall visual effect. Therefore, there is no obvious distinction between them.

Credibility of the use of public evidence

    The focus of dispute over the use of public evidence and website notarization was how to prove the sales time and the authenticity of online sales. Firstly, the original notarization matches its copies, and the website content notarized before a notary office, without any obvious flaw in form. Secondly, is a famous online trading platform in China with a sound management mechanism for the release of information on its website. Its "list of orders" is intended to enable evaluation of the goods sold, and all times are automatically generated by the server, which can be neither modified nor deleted once released. During the process of the invalidation, we highlighted this. The release time shown in the list of orders is earlier than the application date of the patent in question, with attached images for public availability.

The Comparable Design shown in this piece of evidence was finally accepted by the Board.

Application of the invalidation process

    Generally, not until one month after an application for invalidation of a patent is filed can notice of acceptance be received. However, if any litigation is involved, notice can be made available on the day that the application is filed by using the expedited invalidation procedures, provided that the notice to produce evidence and summons relating to the litigation are required, and the invalidation procedures need to be filed within the duration of the notice requiring the production of evidence.

    In this case, as the evidence had not been fully collected, we chose to first file the invalidation procedures based on the existing evidence, and then submit the supplementary evidence and opinions within the one-month period. In this way, we could race against time and promptly receive the notice of acceptance to suspend the litigation procedures, and on the other hand ensure the success of the invalidation application.


The patent in question was declared invalid as a whole by the Patent Reexamination Board.


    The key to success in this appearance invalidation case lies in the analysis of the patent in question and good preparation of evidence. Due to the subjectivity in the evaluation of design patents, especially the degree of evaluation of the combination of comparable documents as specified by the new law, the Patent Reexamination Board is currently more cautious. Therefore, it is necessary for the party requesting the invalidation to find more favourable evidence, which should reflect an obvious inspiration for the combination.

    Secondly is the application of evidence for public use. As a form of evidence, the notarization of the website satisfies the evidentiary requirements. However, the content of the evidence has a very important impact on the merits of the case. In this case, the notarization of websites involved information publicly available on Jingdong, Taobao and the customer's own website. From the preponderance of evidence, Jingdong is a relatively famous website for electricity suppliers in China, and all the lists of orders are under the unified management of Jingdong, with the times of listing automatically generated. Therefore, information from Jingdong has a higher credibility, which was ultimately confirmed by the Patent Reexamination Board. As for the model of cooker, which is always fixed, an explanation had been given in the oral hearing. In addition, the shape of the appearance corresponding to the same model of pressure cooker is also unique.


    There are two points in this case that are worth being noted in subsequent cases.

First, the replacement of part of the integrated structure involved in the design

    The Guidelines for Patent Examination contain provisions from Article 23(2) of the Patent Law which involve an inspiration for the combination as follows: "the following types of combination fall into the circumstances where there is an obvious inspiration for the combination, and designs arising therefrom are not significantly different from the combination of the prior design or its design features: ...(2) the design which is produced by replacing the design feature of a design with another design feature or its slightly changed form of the product of the same or approximate category."

    Despite the foregoing provisions of the Guidelines for Patent Examination, the Patent Reexamination Board still applies certain standards for the recognition of replaced design features. For example, it is easier for the Patent Reexamination Board to accept a replacement of spare parts, because there is an inspiration for such combination. However, there is still uncertainty in the recognition of the inspiration for a combination from a replacement of some features in an integrated design.

    The success of this case can be cited as an example that there is a combination inspiration in the replacement of the features of an integrated design.

Secondly, the recognition of the evidence for public use.

    In this case, other persuading evidence also included the notarization of websites that have certain credibility, as well as the openness regarding the time of the information on such websites, which is generally considered not to be easily changed.