Legal Definitions - all-limitations rule

The all-limitations rule, also widely known as the all-elements rule, is a foundational principle in U.S. patent law. This rule states that for a product or process to *literally infringe* upon an existing patent, the accused product or process must incorporate *every single element* (often referred to as a "limitation") that is specified in at least one of the patent's claims. If even one element or limitation from a patent claim is missing from the accused product or process, there is no literal infringement. This principle ensures that patent holders cannot claim infringement if a competitor's invention omits even a minor component or step explicitly detailed in the patent's claims.

• Example 1: Mechanical Device

  Imagine a patent for a "self-adjusting wrench" that has a claim with three specific elements: (1) a main handle, (2) a movable jaw operated by a spring-loaded gear mechanism, and (3) a digital display showing the jaw opening. A competitor develops a similar self-adjusting wrench that includes a main handle and a movable jaw operated by a spring-loaded gear mechanism, but instead of a digital display, it has a simple analog scale etched onto the jaw.

  How it illustrates the rule: Under the all-limitations rule, the competitor's wrench would likely *not* literally infringe the patent. Even though it shares the handle and the spring-loaded gear mechanism, it lacks the specific "digital display" element described in the patent claim. Because one essential element is missing, there is no literal infringement.

• Example 2: Software Method

  A company holds a patent for a "personalized content recommendation system" with a claim specifying four steps: (1) collecting user browsing history, (2) analyzing history with Machine Learning Algorithm X, (3) generating recommendations based on Algorithm X's output, and (4) displaying recommendations in a dedicated sidebar. A rival company develops its own recommendation system that collects user browsing history, analyzes it with Machine Learning Algorithm Y, generates recommendations, and displays them as pop-up notifications.

  How it illustrates the rule: The rival company's system would likely *not* literally infringe the patent. While it performs similar functions, it uses "Machine Learning Algorithm Y" instead of "Machine Learning Algorithm X" and displays recommendations as "pop-up notifications" instead of "in a dedicated sidebar." Since two specific limitations from the patent claim are not present, the all-limitations rule prevents a finding of literal infringement.

• Example 3: Chemical Composition

  A cosmetic company patents a specific anti-aging serum. One claim in their patent describes the serum as containing: (1) 2% Retinol A, (2) 5% Hyaluronic Acid, (3) 0.5% Vitamin C derivative, and (4) a specific peptide complex, "Peptide Z." A generic manufacturer creates a similar anti-aging serum that contains 2% Retinol A, 5% Hyaluronic Acid, 0.5% Vitamin C derivative, but uses a different peptide complex, "Peptide K," instead of "Peptide Z."

  How it illustrates the rule: According to the all-limitations rule, the generic serum would likely *not* literally infringe the patent. Even though it shares many active ingredients, it omits the specific element "Peptide Z" and substitutes it with a different one. Because not every single limitation from the patent claim is present in the generic product, there is no literal infringement.