JH

John David Hepworth

JG James Robinson Group: 4 patents #1 of 8Top 15%
PL Pilkington Group Limited: 4 patents #11 of 119Top 10%
📍 Preston, GB: #11 of 286 inventorsTop 4%
Overall (All Time): #664,687 of 4,157,543Top 20%
8
Patents All Time

Issued Patents All Time

Showing 1–8 of 8 patents

Patent #TitleCo-InventorsDate
6387512 Grey coloring photochromic fused pyrans David A. Clarke, Bernard Mark Heron, Christopher David Gabbutt, Steven Michael Partington, Stephen Nigel Corns 2002-05-14
6303673 Photochromic compounds David A. Clarke, Bernard Mark Heron, Christopher David Gabbutt, Steven Michael Partington, Stephen Nigel Corns 2001-10-16
6294112 Red coloring hyperchromic 3H-naphtho[2,1-B]pyrans David A. Clarke, Bernard Mark Heron, Christopher David Gabbutt, Steven Michael Partington, Stephen Nigel Corns 2001-09-25
6248264 Neutral coloring photochromic 2H-naphtho[1,2-b] pyrans and heterocyclic pyrans David A. Clarke, Bernard Mark Heron, Christopher David Gabbutt, Steven Michael Partington, Stephen Nigel Corns 2001-06-19
5623005 Photochromic naphthopyran compounds Martin Rickwood, Katharine E. Smith, Christopher David Gabbutt 1997-04-22
5520853 Photochromic compounds Martin Rickwood, Sean D. Marsden, Christopher David Gabbutt 1996-05-28
5446151 Photo reactive spiro-benzoxazine compounds Martin Rickwood, Christopher David Gabbutt, Sean D. Marsden 1995-08-29
4913544 Photochromic articles Martin Rickwood 1990-04-03