| Patent Numbers |
From Date |
To Date |
1 |
1,922 |
|
pre 1841 |
1,923 |
2,400 |
Jan 1841 |
Dec 1841 |
2,401 |
4,910 |
Jan 1842 |
Dec 1846 |
4,911 |
8,620 |
Jan 1847 |
Dec 1851 |
8,621 |
12,160 |
Jan 1852 |
Jan 1855 |
12,161 |
22,430 |
Feb 1855 |
Dec 1858 |
22,431 |
31,230 |
Jan 1859 |
Jan 1861 |
31,231 |
35,290 |
Feb 1861 |
May 1862 |
35,291 |
37,650 |
Jun 1862 |
Feb 1863 |
37,651 |
45,600 |
Mar 1863 |
Dec 1864 |
45,601 |
49,260 |
Jan 1865 |
Aug 1865 |
49,261 |
73,250 |
Sep 1865 |
Jan 1868 |
73,251 |
134,400 |
Feb 1868 |
Dec 1872 |
134,401 |
172,300 |
Jan 1873 |
Jan 1876 |
172,300 |
241,100 |
Feb 1876 |
May 1881 |
241,101 |
338,200 |
Jun 1881 |
Mar 1886 |
338,201 |
418,250 |
Apr 1886 |
Dec 1889 |
418,251 |
478,660 |
Jan 1890 |
Jul 1892 |
478,661 |
533,280 |
Aug 1892 |
Jan 1895 |
533,281 |
610,900 |
Feb 1895 |
Sep 1898 |
610,901 |
639,560 |
Oct 1898 |
Dec 1899 |
639,561 |
673,050 |
Jan 1900 |
May 1901 |
673,051 |
797,700 |
Jun 1901 |
Aug 1905 |
797,701 |
979,180 |
Sep 1905 |
Dec 1910 |
979,181 |
1,152,100 |
Jan 1911 |
Aug 1915 |
1,152,101 |
1,352,120 |
Sep 1915 |
Sep 1920 |
1,352,121 |
1,707,440 |
Oct 1920 |
Apr 1929 |
1,707,441 |
1,839,180 |
May 1929 |
Dec 1931 |
1,839,181 |
2,066,300 |
Jan 1932 |
Dec 1936 |
2,066,301 |
2,268,540 |
Jan 1937 |
Jan 1942 |
2,268,541 |
2,413,670 |
Feb 1942 |
Dec 1946 |
2,413,671 |
2,580,380 |
Jan 1947 |
Jan 1952 |
2,580,381 |
2,775,760 |
Feb 1952 |
Dec 1956 |
2,775,761 |
3,015,100 |
Jan 1957 |
Dec 1961 |
3,015,101 |
3,295,150 |
Jan 1962 |
Jan 1967 |
3,295,151 |
3,631,540 |
Feb 1967 |
Jan 1972 |
3,631,541 |
3,873,830 |
Feb 1972 |
Mar 1975 |
3,873,831 |
4,134,130 |
Apr 1975 |
Jan 1979 |
4,134,131 |
4,471,450 |
Feb 1979 |
Sep 1984 |
4,471,451 |
4,881,020 |
Oct 1984 |
Nov 1989 |
4,881,021 |
5,218,270 |
Dec 1989 |
Jun 1993 |
5,218,271 |
5,525,900 |
Jul 1993 |
Jun 1996 |