5,741
edits
Dating Guide Addendum: Difference between revisions
no edit summary
No edit summary |
No edit summary |
||
| Line 23: | Line 23: | ||
A plausible possibility is that this postponement occurred because of the validity of patent 158709, another Canadian patent for Inner Tube (without flange), which expired in 1926. Although, we can observe the concurrent use of British patents 5861/12 (for Inner Tube) and 116989/17 (Inner Tube w/ Flange) between 1918 and 1926. As we can see, one thing does not exclude the other. | A plausible possibility is that this postponement occurred because of the validity of patent 158709, another Canadian patent for Inner Tube (without flange), which expired in 1926. Although, we can observe the concurrent use of British patents 5861/12 (for Inner Tube) and 116989/17 (Inner Tube w/ Flange) between 1918 and 1926. As we can see, one thing does not exclude the other. | ||
Perhaps, that this patent was used throughout its term and that it was also not used after the concession period - i.e, it was used between 1920 and 1937 on pipes directed to Canada. | |||
<br> | <br> | ||
* See the patent file [https://pipedia.org/images/9/98/CA197365.pdf '''here''']. | * See the patent file [https://pipedia.org/images/9/98/CA197365.pdf '''here''']. | ||