Legal Definitions - appendant claim

An appendant claim, also known as a dependent claim, is a specific type of claim found within a patent application or a granted patent. It refers back to and further defines or limits the scope of a preceding claim, which can be an independent claim or another dependent claim.

Essentially, an appendant claim incorporates all the features of the claim it refers to and then adds one or more additional features, conditions, or limitations. This structure makes the invention described in the appendant claim narrower and more specific than the claim it depends on. Appendant claims are crucial for clearly defining various embodiments of an invention and for providing fallback positions during the patent examination process or in potential legal disputes.

• Example 1: A Smart Home Device

  Imagine a patent application for a new smart home device:

  • Independent Claim 1: A smart home device comprising a housing, a processor, a memory, and a wireless communication module.
  • Appendant Claim 2: The smart home device of Claim 1, further comprising a microphone for voice input.
  • Appendant Claim 3: The smart home device of Claim 2, wherein the wireless communication module is configured for Wi-Fi connectivity.

  Explanation: Claim 2 is an appendant claim because it refers back to Claim 1 and adds a specific feature (a microphone), making the scope of Claim 2 narrower than Claim 1. Claim 3 is also an appendant claim, depending on Claim 2, and further specifies the type of wireless communication. Each appendant claim describes a more specific version of the smart home device initially broadly defined.

• Example 2: A Method for Data Encryption

  Consider a patent for a novel method of securing digital information:

  • Independent Claim 1: A method for encrypting data, comprising receiving plaintext data, applying an encryption algorithm to the plaintext data to generate ciphertext, and transmitting the ciphertext.
  • Appendant Claim 2: The method of Claim 1, wherein applying an encryption algorithm involves a symmetric key encryption algorithm.
  • Appendant Claim 3: The method of Claim 2, further comprising generating a unique symmetric key for each encryption session.

  Explanation: Claim 2 is an appendant claim that depends on Claim 1, specifying the type of encryption algorithm used. Claim 3 is another appendant claim, depending on Claim 2, and adds a step of generating a unique key. Both appendant claims narrow the scope of the data encryption method, describing more particular ways the method can be performed.

• Example 3: A Specialized Medical Instrument

  Let's look at a patent for a new surgical tool:

  • Independent Claim 1: A surgical instrument comprising a handle, a shaft extending from the handle, and an end effector at the distal end of the shaft.
  • Appendant Claim 2: The surgical instrument of Claim 1, wherein the end effector is a grasping mechanism.
  • Appendant Claim 3: The surgical instrument of Claim 2, wherein the grasping mechanism includes serrated jaws.

  Explanation: Claim 2 is an appendant claim that refers to Claim 1 and specifies the type of end effector (a grasping mechanism), making it more specific. Claim 3 is also an appendant claim, depending on Claim 2, and further details the features of the grasping mechanism (serrated jaws). These appendant claims describe increasingly specific versions of the surgical instrument.