Assignee
No assignee recorded.
Inventors
- Unknown
- John H. Bonfield (7 patents)
- Charles J. Cole (13 patents)
- Unknown
- Unknown
- Harry E. Ulmer (19 patents)
- Frederick R. Hopf (9 patents)
- Unknown
- Unknown
US Patent 4990623 · Granted Feb 5, 1991
No assignee recorded.