Legal Definitions - bar date

A bar date, in the context of U.S. patent law, refers to a critical deadline by which an inventor must file a patent application for their invention in the United States. If this deadline is missed, the inventor permanently loses the legal right to obtain a U.S. patent for that invention.

This deadline is typically set one year after the invention has been publicly disclosed or commercially exploited in specific ways. These "triggering events" include:

• When the invention is described in a printed publication (such as a scientific journal, magazine, or conference paper).
• When the invention is patented in another country.
• When the invention is put into public use within the United States.
• When the invention is sold or offered for sale within the United States.

Once any of these events occur, a one-year grace period begins. The patent application must be filed before this one-year period expires.

Here are some examples illustrating how a bar date applies:

• Example 1: Public Disclosure through Publication

  An independent inventor, Dr. Anya Sharma, publishes a detailed article in a widely read engineering journal on March 15, 2023, describing her novel energy-efficient motor design. This publication publicly discloses her invention. The bar date for Dr. Sharma to file a U.S. patent application for her motor design is March 15, 2024. If she fails to file by this date, she will lose her right to obtain a U.S. patent.

• Example 2: Commercial Sale or Offer for Sale

  A startup company, "GreenTech Solutions," officially launches its new smart irrigation system for commercial farms on October 1, 2022, making it available for purchase through their website. This act of offering the system for sale triggers the one-year grace period. The bar date for GreenTech Solutions to file a U.S. patent application covering their smart irrigation system is October 1, 2023. After this date, they cannot obtain a U.S. patent for that specific invention.

• Example 3: Public Use

  An inventor, Mr. Ben Carter, installs a unique, publicly visible, and accessible self-cleaning park bench in a municipal park on June 1, 2023, for public testing and demonstration. Even though he isn't selling it, this constitutes "public use" of the invention. The bar date for Mr. Carter to file a U.S. patent application for his self-cleaning park bench is June 1, 2024. If he misses this deadline, he forfeits his opportunity to secure a U.S. patent.