Start Patent number dating

Patent number dating

From the 1730s onwards patentees were also obliged to file a specification which described their invention in technical detail.

The patent number timeline is as follows: There were a series of dispensers that were manufactured during the mid 70's to mid 80's that did not have a Patent number molded on the stem.

English patents granted before October 1852 were first printed and published in a numbered sequence in the mid-1850s.

Since some patents will have multiple classification numbers, you can widen your net by searching with these numbers.