With the set of Assignment Field Codes you can query any data in a patent's assignment record.  The assignment record is found in the Assignment tab of the Document Details window.  Assignment records contain the following types of data.

1. Inventor Releases: Which are typically excuted prior to the issuance of the patent.
2. Assignment Events: When a patent changes hands or is purchased or acquired by another entity.
3. Security Agreements: When there is a lien on a patent by a bank, shareholder or other entity.
4. Security Releases: When the security agreements above are released by the lien holder.

The assignment data is up-to-date to the nearest week after each weekend's indexing.  However we do provide a direct one-click link to the same data on the USPTO.gov website by clicking the green link to help you confirm the accuracy of our assignment data.

The rows in our assignment records are sorted by default with newest event on top.  Generally this is the most useful presentation and the easiest to read, but the rows are sortable by clicking the column headers.

When a patent changes hands an assignment may be recorded at the USPTO.  Because patents are often assigned many times over their lives, it is most useful to be able to query the most recent assignment date. Use the ANRE_EXE_DT field code to query patents by their most recent execution date.

As with other date fields you can use it with date range or a single date.

To query patents by the number of unique assignment events associated with a patent, use the ANA_ANRE_EXE_CT field code.

Patents with lots of assignment events are sometimes difficult to unwind when trying to clear the title before a transaction takes place. The ANA_ANRE_EXE_CT analysis field helps you determine which patents may require additional work to clear title.

It is not used very often, but it is a handy measure of the potential complexity of a transaction.

To double check you have inventor releases in place, you can query the field by querying for patents where the field is empty:

FIELD:isEmptyANA_ANRE_EXE_CT

If you want to find patents with long or short claim one (1), use the ANA_FCLM_TW field code.

Length of claim one is one of the most important and useful value indicators.  Patents with short claims tend to have far fewer limitations than patents with long, rambling claims.  From talking to many ex patent examiners, short claims are particularly scrutinized for fear that the claim may be overly broad.

For sake of comparison, in 2013 the median length of claim 1 was 156 words.  

Helpful Hint:

Whenever I have to do a claims level review of patents, I first create my queries and isolate the patents that I want to read.  THEN I sort by claim one, "Claim One (Total Words)" with the shortest claims on top.  The reason I do this is to acclimate my brain to the language around the technology from fairly simple claims before I dive into the longer ones.  I do better work every time if I first sort by the length of claim one.

Also Note:

Many published applications have very short claim 1's.  The word is "Cancelled."  So this value indicator is much easier to use when reviewing granted patents.

The pendency is the amount of time between the file date of a patent and the grant date.  To query patents by their pendency use the ANA_PEND field code.

For un-granted applications the pendency is the number of days that have elapsed since the patent was filed.  Once an application "grants" the pendency remains fixed.  AcclaimIP re-computes the pendency field every week.

Pendency is an important value indicator with a unique value profile.  The median pendency is 1126 days or about 3.1 years.  As pendency increases, the average length of claim one also increases suggesting that a long pendency narrows the patent as the applicant responds to rejections from the patent office.  If you've prosecuted patents, then you will not find this surprising.

However, as pendency gets very long, it is an indicator of interference proceedings, and is often NOT indicative of rejections and further narrowing of the scope of the claims.  Therefore, patents with very very long pendencies tend to be some of the most valuable patents.

In the figure below, the ANA_PEND field measures the Pendency Gap.