Patent 5373485

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. 1991-09-03 · reel 005842/0119 · Assignment

    KUMMETH, CHARLES R., BLATTNER, GEORGE W., HOGAN, MICHAEL A., OLSON, ALAN R.MINNESOTA MINING AND MANUFACTURING COMPANY

    original 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

  • Michael A. Hogan (Minnesota Mining and Manufacturing Co)
  • George W. Blattner (Minnesota Mining and Manufacturing Co)
  • Charles R. Kummeth (Minnesota Mining and Manufacturing Co)
  • Alan R. Olson (Minnesota Mining and Manufacturing Co)

All inventors were employed by the original assignee, Minnesota Mining and Manufacturing Co, at the time of filing.

Original assignee

The original assignee is Minnesota Mining and Manufacturing Co (now 3M Co). 3M is a diversified technology company that produces a wide range of products, including those related to data storage. It is highly probable they shipped products embodying the claims, especially given the patent's subject matter (data cartridge systems). 3M Co is currently an operating company.

Assignment timeline

  • 1991-09-03 (executed) / recorded 1991-09-03 — Reel 005842/0119
    • Conveyance: Assignment
    • Assignor: KUMMETH, CHARLES R., BLATTNER, GEORGE W., HOGAN, MICHAEL A., OLSON, ALAN R.
    • Assignee: MINNESOTA MINING AND MANUFACTURING COMPANY
    • Correspondent: Not specified in available data, but the "Free format text" indicates "ASSIGNMENT OF ASSIGNORS INTEREST."
    • Context: Original assignment from inventors to company

The USPTO Assignment Center search for US patent 5373485 shows only the initial assignment from the inventors to Minnesota Mining and Manufacturing Company on September 3, 1991. There are no subsequent recorded assignments for this patent in the USPTO Assignment Center.

Timeline diagram

timeline
    title Ownership of US 5373485
    1991 : Assigned to Minnesota Mining & Manufacturing Co
    1994 : Issued

NPE / troll-pattern signals

  1. Shell-entity transfer — Not present. The only recorded assignment is from the inventors to Minnesota Mining and Manufacturing Company. There are no transfers to entities with names suggesting a licensing-only focus.
  2. Known asserter in the chain — Not present. The current assignee is 3M Co, which is an operating company, not a known NPE.
  3. Repeat correspondent across the chain — Not present. Only one assignment is recorded, and no correspondent information is readily available in the provided snippet beyond the "Free format text" which doesn't list an attorney or firm.
  4. Cascading transfers — Not present. There is only one recorded assignment.
  5. Pre-litigation transfer — Not present. There are no recorded assignments subsequent to the original inventor assignment.
  6. Bankruptcy fire-sale — Not present. There is no indication that Minnesota Mining and Manufacturing Company (3M Co) has undergone a bankruptcy fire-sale related to this patent.
  7. Privateering — Not present. There is no evidence of a transfer to an NPE for assertion on behalf of 3M.
  8. Defensive aggregator (anti-NPE) — Not present. The patent remains with 3M Co, not a defensive aggregator.

Verdict

Insufficient data. The only recorded assignment is the initial transfer from the inventors to the original assignee, Minnesota Mining and Manufacturing Company (now 3M Co). There are no subsequent assignments recorded in the USPTO Assignment Center, making it impossible to identify any NPE or patent-troll patterns.

(Verification search: https://assignmentcenter.uspto.gov/)

Generated 7/4/2026, 12:45:25 PM