Number of Post-Grant Assignment Events (ANA_ANRE_PEXE_CT)
To query patents by the number of assignments registered after a patent was issued, use the ANA_ANRE_PEXE_CT field code.
The ANA_ANRE_PEXE_CT field may be more useful than the ANA_ANRE_EXE_CT field, which counts ALL assignment events. However, the ANA_ANRE_PEXE_CT field stores the number of assignment events recorded after the grant date of the patent. Most PRE-grant assignment events are inventor assignments or inventor releases recorded at the USPTO, and are not transactions.
POST-grant assignment events tend to be transactions or security agreements. The ANA_ANRE_PEXE_CT will help you spot patents with potential problems post-grant.
The assignment (or reassignment) database is how AcclaimIP determines the Current Assignee. If there is a change in ownership, we change the Current Assignee field. AcclaimIP does not change the ownership for Security Agreements that are registered with the USPTO.
Notice in the example above that I have sorted by execution date. If you look at the top Execution Date in the Assignments tab, you will notice that the execution date was 2004-04-04. Now look at the issued date. You can see that this patent was issued in 2001. Therefore, the first assignment was done over 2 years later.
There is a trick to this field when looking for empty fields (i.e., patents with no post-grant assignment events). There are two possible values, empty (null) or 0 (zero). Patents with no assignment history at all have a null value, and patents with an assignment history, but no post-grant assignment history, have a 0 value in the ANA_ANRE_PEXE_CT field.
FIELD:isEmptyANA_ANRE_PEXE_CT OR ANA_ANRE_PEXE_CT:0 --> Finds patents with no post-grant assignment events.
*:* NOT ANA_ANRE_PEXE_CT:[1 TO *] --> Same results as above. Note the *:* (star colon star) that precedes the NOT operator. *:* means all field codes (all data). You can lead a query with a Boolean operator so another possibility is to just query "NOT ANA_ANRE_PEXE_CT:[1 to *]. In the example query, the *:* just says "everything, but NOT this query." You can run either search.