| All Patents in class 33/390 |
Patents 1 -
15
of 16
      |
| Number | Date | Patentee | Title | Type |
| 544,587 | Aug. 13, 1895 | W. Moore | Plumb and Level | levels |
| 666,843 | Jan. 29, 1901 | F.A. Brownell | Spirit Level | camera accessories |
| 811,175 | Jan. 30, 1906 | J.T. Rider | Level | levels |
| 949,842 | Feb. 22, 1910 | H.H. Pugh | Level Device for Braces, &c. | levels |
| 970,360 | Sep. 13, 1910 | W.H. Whigham | Angle guide attachment for boring-tools | |
| 1,409,537 | Mar. 14, 1922 | H.M. Franzen | Universal Level | levels |
| 1,418,544 | Jun. 06, 1922 | J.F. Dodge | Mechanic's Level | metallic levels |
| 1,422,231 | Jul. 11, 1922 | J. Stanley | Combined Level, Plumb, Square, and Measure | levels |
| 1,576,260 | Mar. 09, 1926 | H.F. Waite | Dental Level | levels |
| 2,206,003 | Jun. 25, 1940 | E.B. Donnell | Inclinometer | inclinometers |
| 2,211,201 | Aug. 13, 1940 | W.B. Fell | Machinist's precision level | spirit levels |
| 2,316,777 | Apr. 20, 1943 | W.B. Fell | Machinist's precision level | spirit levels |
| 2,505,166 | Apr. 25, 1950 | A. Wood | Spirit Level | spirit levels |
| 3,030,710 | Apr. 24, 1962 | W.B. Fell | Micro-precision levels | spirit levels |
| 3,034,220 | May 15, 1962 | W.B. Fell | Micro-precision level | machinist levels |
