As it is once again Canada Day, I dug around in my collection for something suitably Canadian to mark the occasion. As mentioned previously, Canada was not especially known for its manufacture of drawing instruments, most of which were imported from Germany and rebadged for sale by Canadian retailers such as Hughes-Owens.
However, I did recently come across an unusual spring steel rule, both manufactured and patented in Canada.
When fully unrolled it measures three feet in length, or 91.3 cm on the metric edge, but by simply snapping its slightly curved profile at one end the ruler coils up into a tight cylinder just 4 cm in diameter.
In this configuration it can be easily carried in its neat “real hide” snap-fastener case, which is (ironically?) marked “Yard stick”.
The fact that the case was made in England suggests that this particular ruler was always intended for export.
Although patented and manufactured in Canada, the original idea was the result of an unlikely collaboration between an inventor and entrepreneur from Tennessee, John Burton Tigrett, and Edwin Earl Foster, a Texan specialist in spring design.
Tigrett’s background was in toy production, having developed his uncle’s business the Tigrett Toy Company. He clearly had ambitions to move beyond toys, naming his own company Tigrett Industries Inc., but toys remained his bread and butter as can be seen from the numerous patents taken out by the company during the 1950s and ’60s, many of which are illustrated in this 1959 Tigrett toy catalogue.
Edwin Foster, on the other hand, had long focused on the properties of steel springs, taking out dozens of patents for applications including spring-assisted ironing devices, spring sash window counterbalances and the hose-retracting mechanism on gasoline pumps.
Together, they were responsible for the two patents found on today’s Canadian-made spring ruler, CA653379 and CA662839 of 1962 and 1963 respectively, the first of which illustrates the concept for a roll-up ruler that stays straight when fully extended.
Other applications of the same patent included a retractable tape measure – now the standard form throughout the world – and an adjustable light fitting using counterbalanced springs that enabled it to be raised or lowered to any position. All exploited the properties of Foster’s cross-curved profile, which allowed the spring to remain in a stable straight configuration.
While the steel tape measure may have been the most universally-used of Tigrett’s inventions, it is perhaps fitting that the simple ruler design was revived as the now ubiquitous slap bracelet, returning to its origins as the brainchild of a toy maker.
