In Chile, interpretation of patents must be made according to article 49 paragraph 3 of the Law and article 44 paragraph 1 of the bylaw. According to these rules, the scope of the protection granted by the patent is determined by the content of the claims, which therefore constitute the only object of interpretation; the descriptive memory and the drawings only serve as secondary elements to interpret the claims.

The latter means that our local Industry Property Law have adopted the claim system in order to determine as precisely as possible the object of patent protection. Thus, when it comes to a patent infringement, the problem often merges because the literal wording of the claim normally does not fully cover the protectable object from the point of view of the reason for protection.

In this sense, a first option is to follow a literal interpretation of the claims, however, this legal avenue in some cases may weaken the protection and incentives associated with the registration of a patent, because in order to circumvent that protection and to illegitimately take advantage of someone else's invention, it would be sufficient to introduce insubstantial and irrelevant modifications to an invention.

This risk can be seen even more clearly if we take into account that inventors cannot write the claims in very broad or general terms, since in such a case the National Institute of Industrial Property (INAPI) normally tends to restrict the literal wording as a condition in order to grant a patent application.

Having said that, when it comes to patent infringement, the challenge is try to avoid a literal and strict interpretation of the claims in order to protect and encourage the patent system, but at the same time without giving to the patent owner a broader monopoly on what he did not apply for in time, or on what is part of the prior art and therefore cannot be appropriated.

This problem has been addressed in countries like United States of America, Germany and Great Britain through the doctrine of equivalents.

This doctrine can be defined in the following terms:

“A means by which a patentee may raise a claim of infringement even though each and every element of the patented invention is not identically present in the allegedly infringing product.  The purpose of the doctrine is to prevent an infringer from stealing the benefit of a patented invention by changing only minor or insubstantial details of the claimed invention while retaining the same functionality.  The essential inquiry in determining equivalency is whether the accused product or process contains elements identical or equivalent to each claimed element of the patented invention”.1

Indeed, in the United States of America we can find several caselaw related to this doctrine. One of the most relevant is Graver Tank & Mfg. Co. v. Linde Air Prods., Inc., in which the U.S. Supreme Court held that a patentee may invoke this doctrine to proceed against the producer of a device if it does substantially the same function in substantially the same way to obtain the equal result, establishing the "triple identity" test for equivalence.

In addition, the US Supreme Court enunciated the "all elements" test for equivalence in Warner-Jenkinson v. Hilton Davis Chemical Co., in which this doctrine should be applied to each individual element of a claim, not to the invention as a whole, arguing that every element of the patented invention, or its substantial equivalent, is present in the infringing  product or process.

In addition, it is important to point out that the proper time for evaluating whether an accused element is equivalent to a claimed element is at the time of infringement, not at the time the patent was issued. 

Although this doctrine is not established in the Chilean law, a civil judge has applied this doctrine in a civil infringement case (Milton Astudillo Capetillo v CODELCO, Second Court of Calama, C-50763-2009) under a triple identity rule, by following international doctrine on the matter and adopting a broad interpretation of the Bylaws of our Industrial Property Law, which define the term ‘technical equivalent', holding that such equivalents may infringe a patent application.

In the relevant part, this ruling sets forth the following:

“In this order of ideas, in order to stablish the scope of the claims of the procedure patented by the plaintiff, in relation to that procedure referred to as infringing and developed in the Radomiro Tomic field, it is expressly recognized in our legislation - as from the year 2005 -, the doctrine of equivalents, which is nothing else than to affirm that there is identity between the patented invention and its equivalent, that is to say, according to the report in comment "The substantial equivalent of a thing, in the sense of the patent law, is the same as that thing;  so that if two devices perform the same work in substantially the same way, and achieve substantially the same result, both are the same, even if they differ in name, form or appearance. ”

“That in this sense, as already indicated in Article 2 of the Regulations of Law No. 19,039, it refers that the technical equivalent is understood as: "an element or means that performs the same function as that claimed in an invention, in the same manner and producing the same effect or result indicated in the claim". What leads to accept that the patented invention is equal to its equivalent, and will be as long as there is a triple identity, so: a) function, b) form that meets, and c) result obtained identical to that indicated in the claim”.

This decision applies the Doctrine of Equivalent based on the definition of technical equivalent stated in a bylaw, however, this regulation does nor stablish this doctrine neither allow a broad interpretation of the claim. In this case, the defendant filed an appeal and a constitutional action that triggered a negotiation and agreement; thus, the Court of Appeal did not have the chance to review the case.

To sum up, it can be said that despite the fact that our Industrial Property Law does not recognize this doctrine, stating that the scope of the protection granted by the patent is determined by the content of the claims, the definition of technical equivalent stated in an Industrial Property Bylaw could come in handy to argue the eventual application of this doctrine. We will have to wait for new decisions to see a development of this doctrine, hopefully with cases before the Court of Appeal and/or the Supreme Court.


1 Cornell Law School. Site:

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