FH

Fred W. Hefer

OY Oyo: 1 patents #4 of 7Top 60%
Overall (All Time): #2,348,591 of 4,157,543Top 60%
2
Patents All Time

Issued Patents All Time

Showing 1–2 of 2 patents

Patent #TitleCo-InventorsDate
4594698 Printed-circuit disc for stringing geophones — 1986-06-10
4525819 Horizontal geophone transducer assembly — 1985-06-25