Assignee
Inventors
- Dirk Erickson (11 patents)
- Robert Albertus Brondijk (41 patents)
- Jacobus Petrus Josephus Heemskerk (18 patents)
- Jakob Gerrit Nijboer (46 patents)
- Christiaan Steenbergen (23 patents)
- Charles R. Weirauch (36 patents)
US Patent 8144555 · Granted Mar 27, 2012