Dating Canadian Zippos
After writing the first page in this guide, I received emails questioning my dating of the removal of the "Patented 1950" legend from both the insert and the lighter case. Other published works and websites state that this was removed in 1963. I do not believe this to be the case.
The Canadian Patent was issued on 28th November 1950 and expired on 28th November 1967. If we look at the Zippo lighters manufactured in the United States the original patent (2032695) was issued on 3rd March 1936. This patent number was carried on all lighters made until early 1953 a period of 17 years. Zippo had applied for, and been granted a second patent, which was actually for the flint tube. This was patent 2517191. This patent was issued on 1st August 1950, and on the expiry of the earlier patent this number was stamped on lighters. This number continued to be used until late 1967, again a period of 17 years.
If the Canadian patent details were in fact removed in 1963, the question has to be asked, Why? Zippo in the US were keen to protect their design by the use of patent numbers, so what was the difference in Canada?
It is my belief that somewhere in the annuls of time, the date of 1963 was suggested as the removal date for Pat 50, and this has then become the norm. My research when creating this page included looking at the lighters in my own collection and contacting other collectors to seek their advice. I have been advised of a number of "dated" lighters (where an anniversary date is engraved on the face of the lighter) which are dated after 1963, (see photograph at the bottom of this page) but the lighter itself carries the Pat 50 markings. This adds weight to my own assumptions.
I have also been questioned on the supplied dates of the change over in the cam-spring. I have suggested that the narrow cam-spring was introduced in 1970. My dates were based on my own collection of US stamped lighters, which were already date coded at this time. The earliest I have found a narrow spring is 1970. It could be that these springs were trialled on Canadian lighters earlier than 1970, but I can see no reason why this would be the case. If you know different, please feel free to contact me.
Further research will be required in order to prove or disprove my assumptions and I will update the page as I receive any further information.
This is the Canadian Patent page for Zippo Lighters, clearly showing the commencement and end date of the patent
A 1967 lighter where the "Pat 50" stamp can be seen.