© 2003, Dawsey Co., LPA
March 2003

We tend to think of the grant of a patent as establishing a set body of rights, in the form of claims that continue in force and unchanged throughout the term of the patent. Most of the time, that’s exactly what happens. However, there are circumstances in which the claims of a patent, as granted, are not the last word on what might, or might not, infringe the patent.

The law allows the establishment of “intervening rights,” or rights that would otherwise infringe issued patents, under three very specific circumstances. These circumstances arise when the scope of a patent is changed by either reissue or reexamination, or where a patent is revived after failure to pay a maintenance fee. The concept is one of fairness; if the claims of a patent change in scope or enforceability, it would be fair to allow practices that might otherwise be infringements, because the so-called infringers had no way of firmly predicting the final scope of the patent claims.

All of these “intervening rights” are provided by explicit statutes. In the reissue statute, 35 U.S.C. S 252, two types of intervening rights are established. In a reissue, the grantee asks the patent office to allow the additional claiming of material that while supported in the original disclosure, was defectively specified or claimed, or inadvertently not claimed. As a result, new claims, granting new and broader scope, may be added to the patent.

To protect those who might, in good faith, have relied on the original grant of the patent to delineate the bounds of its claims, absolute intervening rights are granted to those who, “prior to the grant of a reissue, made, purchased, offered to sell, or used unless such thing infringes a valid claim of the reissued patent which was in the original patent.” Such intervening rights are mandatory upon the court, as indicated by the language “a reissued patent shall not abridge ”

A second class of intervening rights, equitable intervening rights, is extended even to those who made “substantial preparation” to practice an aspect of the invention later barred by a new claim in the reissue. These equitable intervening rights are within the discretion of the court, which by statutory language is instructed, “The court before which such matter is in question may provide ” The difference between absolute and equitable rights can be important in an infringement defense. Equitable rights, the weaker of the two, are an affirmative defense and are waived if not pleaded, or at least raised, at trial during the liability phase of the suit. On the other hand, failure to raise the issue of absolute intervening rights is not a waiver of those rights, which can be raised even after the liability phase has concluded.

In the second situation where intervening rights may be established, 35 U.S.C. S 307(b) provides for intervening rights following reexamination. A reexamination re-opens a patent to new scrutiny by the patent office, and existing claims may be lost, or new claims approved. If a claim is amended, or a new claim allowed, the effect is similar to that of a reissue patent. Absolute rights are granted to those actually practicing an activity infringing a new claim, while equitable rights are granted to those who may have made “substantial preparations” to do so.

The last situation where intervening rights may be established is following a successful petition to accept a late maintenance fee that was unavoidably or inadvertently not paid. A patent holder normally has six months following the due date for a maintenance fee to have the required fee to the patent office, or the patent will be deemed abandoned and its teaching will pass into the public domain. (See “Pay Those Maintenance Fees” in last month’s newsletter at www.invention-protection.com) If the patent holder can convince the Commissioner, within 24 months following the abandonment of the patent, that the failure to pay the maintenance fee was either unavoidable or inadvertent, the Commissioner may order the patent reinstated. In order to protect those who relied on the presumptive abandonment of the patent, absolute and equitable intervening rights are again allowed. Absolute rights are extended to those who actually practiced the patent during the period of abandonment, while equitable rights “may” be extended to those who made “substantial preparation” to do so. These rights are limited to the period beginning after the six month grace period after the maintenance fee due date up to the date that the Commissioner actually accepts the delayed maintenance fee and grants the petition.

This doctrine of “intervening rights” essentially allows one to rely on patents as issued or as abandoned, such that later changes in scope or petitions to revive abandoned patents do not unfairly impact good faith, but technical, “infringers.”