Why do sewer rats grow so much larger then pet rats do? Are they a different species and if so how come they do not make it into the pet trade as in captive bred clean versions? I saw a rat as big as two large cats within one the other day and this got me to thinking, hence the question above.
In the United States, under current patent law, the term of patent, provided that maintenance fees are paid on time, are: 1  For applications filed on or after June 8, 1995, the patent term is 20 years from the filing date of the earliest U.S. or international (PCT) application to which priority is claimed (excluding provisional applications).
2 to 3 years. Time it takes for an invention to receive a patent. âLong waiting times at the U.S. Patent Office. From the time an application is filed, it takes two to three years for an invention to receive a patent -- enough time for some high-tech ideas to become obsolete.8 months to 2 years. Length of time patent examination process can take. The examination process can take from 18 months to two years. Inventors can use the phrase 'patent pending' to indicate they have begun the patenting process.