| All Patents in class 33/290 |
Patents 1 -
15
of 15
      |
| Number | Title | Classification(s) |
| 30,914 | Collimator | 33/290, 33/348, 356/248 |
| 79,266 | Spirit Level | 33/290 |
| 79,582 | Level Sights | 33/290 |
| 313,657 | Surveying Instrument | 33/282, 33/290, 33/367 |
| 359,236 | Spirit Level | 33/290 |
| 360,536 | Leveling Instrument | 33/290 |
| 360,837 | Leveling Instument | 33/290 |
| 365,033 | Spirit Level | 33/290, 33/379 |
| 402,869 | Sighting Attachment for Levels | 33/290 |
| 405,624 | Sighting Attachment for Spirit-Levels | 33/290 |
| 479,518 | Leveling Instrument | 33/290 |
| 948,777 | Combined Square, Level, and Plumb | 33/290, 33/370, 33/371, 33/498 |
| 1,189,422 | Sighting attachment for levels | 33/290 |
| 1,265,823 | Level | 33/283, 33/290, 33/351, 33/354, 33/387 |
| 2,981,141 | Optical Compensator and Tilt Detector | 33/290, 356/250 |
