Patent claims in Patstat

Recently available, the count of patent claims in TLS211 in patstat, looks like a very promising piece of information.

Coverage of such data is quite good, here the counts for the two publication authorities covered:

 

EP	2669148
US	4574142

About time coverage here are the figures for last 30 yrs in percentage (consider obviously that some publication kinds do not have a figure for claims) on allover US and EP patstat publications, by publication year

1978	99,7%	1996	84,0%
1979	97,7%	1997	81,3%
1980	96,8%	1998	81,5%
1981	93,0%	1999	80,0%
1982	90,3%	2000	76,3%
1983	90,3%	2001	68,1%
1984	89,3%	2002	50,6%
1985	87,4%	2003	47,8%
1986	85,6%	2004	44,5%
1987	84,0%	2005	41,2%
1988	82,5%	2006	44,7%
1989	83,2%	2007	42,8%
1990	80,5%	2008	41,8%
1991	78,0%	2009	41,0%
1992	79,1%	2010	45,0%
1993	82,6%	2011	47,2%
1994	85,0%	2012	43,2%
1995	83,1%

Anyway several caveat must be introduced:

1) Number of claims depends on publication language
Same patent, issued in German may have 1 or 2 claims less than in English

2) Number of claims may be different in different publications of same patent

 Take FI patent EP  1186609; in TLS211 for october 2012 you will find

26, 'EP', '        1186609', 'B1', 10, '2008-12-03', 'DE', 1, '0008'
27, 'EP', '        1186609', 'A3', 10, '2002-10-02', 'DE', 0, ''
28, 'EP', '        1186609', 'A2', 10, '2002-03-13', 'DE', 0, '0009'

that means publication kind A2 lists 9 claims, while B1 lists only 8.

And if we check on original documents:

http://worldwide.espacenet.com/publicationDetails/claims?CC=EP&NR=1186609A2&KC=A2&FT=D&ND=3&date=20020313&DB=worldwide.espacenet.com&locale=en_EP


http://worldwide.espacenet.com/publicationDetails/claims?CC=EP&NR=1186609B1&KC=B1&FT=D&ND=4&date=20081203&DB=worldwide.espacenet.com&locale=en_EP

We see in phase B1 one claim has been withdrawn.
Now it depends from our research question to decide if it is better to consider older (A2) or more recent (B1) number of claims.