Patent numbers:
NL 0 614 508
Europe 0 614 508
USA 5.556.262
Japan 3382617
Patent numbers:
NL 0 683 854
Europe 0 683 854
USA 5.473.893
Japan 3181292
Patent numbers:
NL 0 975 861
Europe 0 975 861
USA 6.279.517
Patent numbers:
NL 0 772 734
Europe 0 772 734
USA 5.983.638
Patent numbers:
NL 0 613 521
Europe 0 613 521
USA 5.482.445
Patent numbers:
NL 1000788
Patent numbers:
NL 0 681 645
Europe 0 681 645
USA 5.540.193
Japan 338023
Patent numbers:
NL 1006143
Europe 0 985 087
Patent numbers:
NL 0 772 735
Europe 0 772 735
USA 5.829.393
Patent numbers:
NL 1013996
NL 1013993
,,Everything that can be invented has been invented.''
Charles H. Duell, Commissioner, U.S. Office of Patents, 1899.
