|
GB539271A
|
Improvements in or relating to the measurement of surface r… |
Expired / Lapsed
|
1940-02-01 |
— |
0 |
Details
|
|
US2363691A
|
Apparatus for measuring or indicating the degree of surface… |
Expired / Lapsed
|
1942-09-16 |
1944-11-28 |
0 |
Details
|
|
US2329084A
|
Apparatus for measuring and/or indicating surface roughness |
Expired / Lapsed
|
1941-02-18 |
1943-09-07 |
0 |
Details
|
|
US2179799A
|
Optical projection apparatus |
Expired / Lapsed
|
1938-04-27 |
1939-11-14 |
0 |
Details
|