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US1824204A
|
|
Sign construction
|
|
US1829791A
|
|
Device for recording sound on film
|
|
GB357516A
|
|
Improvements in electrodes for positive column luminous gaseous conduction tubes andprocess of making same
|
|
GB351006A
|
|
Improvements in electron emitting cathodes
|
|
US1811083A
|
|
Insulator and clamp for use in electrical work
|
|
US1822361A
|
|
Electrode for electrical discharge devices
|
|
US1815913A
|
|
Split clamp for mounting insulator to face of sign or other object
|
|
US1822360A
|
|
Projection lamp
|
|
US1822359A
|
|
High electron emissive cathode
|
|
US1813990A
|
|
Film spool
|
|
US1758221A
|
|
Motion-picture camera
|
|
US1798144A
|
|
Motion-picture projector
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