What follows are the subclasses from one class of the Manual of Classification for US patents. As you scroll through the list and encounter a class/subclass of interest, you can jump back to the top and retrieve patent titles by entering the class/subclass in the box below.
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363-131 121-55A 14-.5
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classes of the form Dxx.yy) are not retreivable.
Class Number: 23 Class Title: CHEMISTRY: PHYSICAL PROCESSES Subclass Subclass Number Title 293 R PHYSICAL PROCESSES 294 R .Sublimation 294 S ..Sulfur 295 R .Crystallization 296 ..Selective 297 ...With extraction 298 ...From natural sources 299 ..With extraction 300 ..With added material 301 ...Seed 302 R ..Alkali metal and ammonium compounds 303 ...Common salt 302 A ...Ammonium compounds 302 T ...Sodium compounds 304 ..Alkaline earth metal and magnesium compounds 305 R ..Heavy metal or aluminum compounds 305 A ...Aluminum compounds 305 F ...Iron compounds 305 RE ...Rare earth compounds 295 G ..Gel 295 S ..Solar 306 .Concentration of liquids in liquids 307 ..With direct heating 308 R .Melting out 308 S ..Sulfur 313 R .Agglomerating 314 ..Carbon 313 AS ..Silicate 313 FB ..Fluidized bed 313 P ..Pan agglomeration 293 S .Sulfur 293 A .Flaking, spraying