Some patent tools you must know

 Patent Library

Patent Library allows users to search by patent number and get OCR'ed PDFs of patent 

documents.

Fetures: A person can get OCR'ed patent of major authorities like (JP, US, CN, EP, WO, GB, FR and DE ) and other authorities like ( CA, MX, AR, CL, IL, OA, DD, NO, SE, CH, AT, DE, BE, IE, IT, ES, NL, LU, RU, SU, UA, MD, HU, CZ, CS, HR, SI, LT, LV,  MC, and DZ).

MaxVal free IP tools

Maxval-ip give a variety of free patent tools which can improve your searching. some of them are

Claim Chart Generator

Claim Set Comparison Tool 

Patent Family Tree 

Foreign Filing Fee Calculator

IPSCORE 

IPSCORE is a free patent valuation tool from esp@cenet. It is one of the best free patent valuation tool available. According to some attorneys its accuracy is about 80% of the original value of the patent. So if you are inventor and just want to know what your patent might worth, this free tool can help you to know the potential of your invention.