A guide to US Patent numbers.

First, a few words about Patent numbers:

The first Patent number was issued in 1836. It was simply (1)
When you want to find when a item was made, and you can find it's Patent number use the largest number you can find. Most items list many Patent numbers. The only one you need to know is the last, and largest one listed. There are exceptions to this rule, but we will only concern ourselves with the largest number here.
On tv sets, it's normally on the back of the set, on a small paper label. On other items, you have to look everywhere. It will always be listed as shown below. The smallest number is the oldest, the larger the number, the newer the item.

Remember, use the LARGEST number
listed on your item!!!

The number of the first Patent issued in each calendar year is shown. Find the two numbers (smaller and larger) which are closest to your Patent number. The year next to the smaller number, is the year the Patent was issued.

Patent # 1 to 110,616

Patent # 110,617 to 1,013,094

Patent # 1,013,095 to 2,536,015

PATENT # 2,536,016 to 4,490,885

More to come soon

Last modified on Sunday, October 04, 1998