Voigt Patents Limited
1933 - 1950
1933 - 1950
1902 - 1983
1889 - 1954
1904 - 1980
1903 - 1992
1910 - 1961
1907 - 1969
1912 - 1988
1884 - 1960
1824 - 1866
1982 - 1988
1888 - 1986
1879 - 1952
1804 - 1889
1898 - 1978
1947 - 1966
1907 - 1966
1788 - 1867
1775 - 1204
1772 - 1813
1998 - 2006
1913 - 1936
1862 - 1931
1960 - 1977
1901 - 1995
1864 - 1965
1865 - 2002
1833 - 1900
1943 - 2012
1866 - 1944
1904 - 1971
1867 - 1933
1779 - 1843
1785 - 1846
1911 - 1998
1793 - 1867
1903 - 1966
1864 - 1939
1907 - 1978
1854 - 1939
1911 - 1959
1891 - 1970
1891 - 1954
1903 - 1989
1863 - 1922
1916 - 2005
1913 - 1964
1887 - 1948
1848 - 1919
1906 - 1983