Patent 9421713B2

Assignment history

Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.

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Ownership chain (1)

Asserters network →

Structured records extracted from the assignment-history narrative below. Each entity links to its full ownership-network profile.

  1. 2013-03-08 · recorded 2013-03-27 · reel 029672/0836 · ASSIGNMENT OF ASSIGNORS INTEREST

    LARSON, GARY; SCHLOESSER, RONALD G.; SWANSON, WILLIAM J.STRATASYS, INC.

    Correspondent: ROBERT E. MAIMES · THOMAS | KAYDEN | HORSTEMEYER & RISLEY

    initial assignment

Assignment history

Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.

✓ Generated

Inventors

  • William J. Swanson (Employer: Stratasys Inc., inferred)
  • Ronald G. Schloesser (Employer: Stratasys Inc., inferred)
  • Gary Larson (Employer: Stratasys Inc., inferred)

The inventors assigned their interest to Stratasys Inc. on the filing date of the patent application (2013-03-08), which is a common practice for employees of companies. There are no unusual patterns suggesting the inventors departed the original assignee shortly after filing.

Original assignee

The entity named on the issued patent is Stratasys Inc.

Stratasys Inc. is a major operating company that ships products embodying the claims of US9421713B2. Their primary line of business is the development, manufacture, and sale of 3D printing and additive manufacturing systems, materials, and services. The patent, titled "Additive manufacturing method for printing three-dimensional parts with purge towers," directly relates to the functionality and efficiency of their 3D printing systems. Stratasys Inc. is currently an active, operating, publicly traded company.

Assignment timeline

  • 2013-03-08 (executed) / recorded 2013-03-27 — Reel 029672/0836
    • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
    • Assignor: LARSON, GARY; SCHLOESSER, RONALD G.; SWANSON, WILLIAM J.
    • Assignee: STRATASYS, INC.
    • Correspondent: ROBERT E. MAIMES, THOMAS | KAYDEN | HORSTEMEYER & RISLEY, LLP, ONE SUNTRUST PLAZA, 303 PEACHTREE STREET, NE, SUITE 1500, ATLANTA, GEORGIA 30308. This is the only correspondent appearing in this patent's assignment chain.
    • Context: Initial assignment of patent rights from inventors to their corporate employer.

No other assignments for US9421713B2 are recorded at the USPTO Assignment Center as of 2026-06-15.

Timeline diagram

timeline
    title Ownership of US 9421713B2
    2013 : Inventors assign to Stratasys Inc
    2016 : Patent granted
    2024 : US litigation filed
    2025 : PTAB case filed

NPE / troll-pattern signals

  1. Shell-entity transfer — Not present. The patent was assigned directly from the individual inventors to Stratasys Inc., a well-known operating company (Reel 029672/0836).
  2. Known asserter in the chain — Not present. Stratasys Inc. is an operating company, not identified as a known NPE.
  3. Repeat correspondent across the chain — Not present. Only one assignment is recorded for this patent, thus no recurring correspondent can be observed within its chain.
  4. Cascading transfers — Not present. Only one assignment is recorded for this patent, which is from the inventors to Stratasys Inc.
  5. Pre-litigation transfer — Not present. The initial assignment to Stratasys Inc. occurred in 2013 (Reel 029672/0836). Litigation involving this patent was first filed in 2024, more than six months after the last recorded assignment.
  6. Bankruptcy fire-sale — Not present. Stratasys Inc. is an active, operating company and there is no indication of bankruptcy.
  7. Privateering — Unclear. While Stratasys Inc. is an operating company engaged in litigation involving this patent, there is no public information provided that suggests they transferred the patent to an NPE for assertion on their behalf. This appears to be a direct assertion by the operating company.
  8. Defensive aggregator (anti-NPE) — Not present. The patent is currently held by Stratasys Inc., not a defensive aggregator.

Verdict

Operating-company assertion

The patent US9421713B2 was originally assigned from the inventors to Stratasys Inc. on March 8, 2013 (Reel 029672/0836), and no subsequent assignments have been recorded. Stratasys Inc. is a major operating company in the additive manufacturing industry and the patent's subject matter is directly relevant to their products and services. The patent has been involved in multiple US litigations since 2024 and a PTAB case since 2025, indicating assertion by the current owner, Stratasys Inc..

Verification link: https://assignmentcenter.uspto.gov/

Generated 6/15/2026, 12:45:44 PM