Duane Charles John Engdahl

📍 Phoenix, AZ: #1,944 of 6,660 inventorsTop 30%

🗺 Arizona: #10,057 of 32,909 inventorsTop 35%

Overall (All Time): #1,581,735 of 4,157,543Top 40%

Patents All Time

Issued Patents All Time

Showing 1–3 of 3 patents

Patent #	Title	Co-Inventors	Date
7374500	Putter with fixable shaft that rotates to convert the putter from practice to play	—	2008-05-20
7041004	Putter with rotatable shaft for converting from practice to play	—	2006-05-09
6776727	Balanced putter for practice and play	—	2004-08-17