Issued Patents 2011
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 8074660 | Expandable face mask with engageable stiffening element | — | 2011-12-13 |
| 7896940 | Self-supporting pleated filter media | Douglas C. Sundet, Donald E. Young, Lowell E. Christensen | 2011-03-01 |