USPC Class Details – HistoricIP

Description: 91 motors: expansible chamber type / 91 motors: expansible chamber type/(218) cyclically operable (247) timing control by relative adjustment of plural movable fluid control elements (252) cut off adjustable relative to admission (253) inlet controlled by relatively cyclically moved elements (256) cut off adjustable relative to reciprocating admission element (257) oscillating admission element

Hierarchy/Derived subclasses

91 / 218

-> 247

-> 252

-> 253

-> 256

-> 257

uspto searches

Patent Apps in 91/257

Granted Patents in 91/257

Use the links above or do an advanced search in ppubs for:
(91/257.ccls.)

This will show what classes derive from the input. Ex: entering 43/42.24 shows the derived classes and the search that can be used to find patents or patent applications in those subclasses.