John A. Duff — 3 Patents at 3M

John A. Duff has been granted 3 US patents while listed as an inventor at 3M. The first was granted in 2016 and the most recent in November 2024. John A. Duff ranks #1,328,092 of 4,157,543 US inventors in our database (top 31.9%). Patent records list John A. Duff in Holly Springs, NC, US.

Issued Patents All Time

Showing 1–3 of 3 patents

Patent #	Title	Co-Inventors	Date	Approx Value ⓘ
12138491	Powered exhaust apparatus for a personal protection respiratory device	Desmon T. Curran, Benjamin H. Cooper, Jason A. Graves, Reyad A. Abdulqader	2024-11-12	$80,876,000
11554233	Powered apparatus for a personal protection respiratory device	Benjamin H. Cooper, Jason A. Graves, Henning T. Urban	2023-01-17	$69,574,000
9404952	Conductivity measurement of fluids	Michael Druga, Josip Simunovic	2016-08-02

John A. Duff — 3 Patents

Issued Patents All Time

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