Assignee
Inventors
- Henriette C. Van Den Broeck (8 patents)
- Leendert Hendrik De Graaff (15 patents)
- Jan Dirk Rene Hille (3 patents)
- Albert Johannes Joseph Van Ooyen (12 patents)
- Jacob Visser (35 patents)
- Abraham Harder (6 patents)
US Patent 5358864 · Granted Oct 25, 1994