Classy Patents

Perseverance in patent searching pays off in the long run. One tactic is to begin the search with a key word like “dibenzothiophene.” Explore the results of the search for patents of interest, and then do another search by the primary classification number(s) assigned to those patents. The result will be a list of patents that may also be of interest, even though they may or may not contain the key word of your initial search.

Example …
A search on the USPTO patent database (http://patft.uspto.gov/) using for patents issued in 2008 containing the keyword “dibenzothiophene” (SPEC/dibenzothiophene AND ISD/1/$/2008) results in seven hits, listed below.

PAT. NO. Title
1 7,321,012 Method of crosslinking intrinsically conductive polymers or intrinsically conductive polymer precursors and the articles obtained therefrom
2 7,320,955 Compositions comprising complexes of cyclodextrin and at least one laundry treatment active
3 7,320,849 Organophotoreceptor with a charge transport material having two epoxidated-hydrazone groups
4 7,318,966 Luminescent element material and luminescent element comprising the same
5 7,318,845 Compact distillates fuel processor with effective sulfur removal process
6 7,315,722 Image forming apparatus and image forming method
7 7,314,545 Desulfurization process

Clicking on item 5 reveals the following …

United States Patent 7,318,845 (January 15, 2008)
Compact distillates fuel processor with effective sulfur removal process
Abstract
A distillate fuel steam reformer system in which a fuel feed stream is first separated into two process streams: an aliphatics-rich, sulfur-depleted gas stream, and an aromatics- and sulfur-rich liquid residue stream. The aliphatics-rich gas stream is desulfurized, mixed with steam, and converted in a reforming reactor to a hydrogen-rich product stream. The aromatics-rich residue stream is mixed with air and combusted to provide heat necessary for endothermic process operations. Reducing the amounts of sulfur and aromatic hydrocarbons directed to desulfurzation and reforming operations minimizes the size and weight of the overall apparatus. The process of the invention is well suited to the use of microchannel apparatuses for heat exchangers, reactors, and other system components, which may be assembled in slab configuration, further reducing system size and weight.
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Inventors: Shaaban; Aly H. (Lynn Haven, FL), Campbell; Timothy J. (Parker, FL)
Assignee: Applied Research Associates, Inc. (Albuquerque, NM)
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Current U.S. Class: 48/61 ; 208/133; 208/208R; 208/213; 208/220; 208/308; 208/46; 208/49; 208/51; 208/57; 208/58; 208/67; 208/68; 208/69; 208/73; 208/78; 208/79; 208/80; 208/83; 48/127.9; 48/128; 48/211; 48/84
The primary U.S. Class number is listed first, in bold. Using that number to conduct a subsequent search, limited to a 2008 issue date (CCL/48/61 AND ISD/1/$/2008), reveals …

PAT. NO. Title
1 7,318,970 Architectural hierarchy of control for a fuel processor
2 7,318,846 Mixture formation means for a reformer of a fuel cell system or for a heater
3 7,318,845 Compact distillates fuel processor with effective sulfur removal process
4 7,316,718 Differential pressure-driven borohydride based generator

You can go on forever like this, or until your perseverance wears out.