Dating us patent numbers
From 1933 to the mid 50s, the word Zippo was stamped in block letters. What began as a quality-control tool for Zippo founder George G. To identify a potential pattern in any run of lighters returned for repair, the bottom of every Zippo lighter was encoded with a series of markings.The Zippo script logo was developed in the late 40s and was phased-in on the lighter bottom stamp around 1955. Since the 1950s, those markings provide a way to accurately date most Zippo lighters. Blaisdell's world-famous guarantee that "It works or we fix it free™" still covers every Zippo windproof pocket lighter today.The new patent was added to the labels and games produced from 1936 - 1941 included both patents printed on the labels.When the 1924 patent expired in 1941, they dropped that number from the labels and used only the later patent issued to them.This is a technical discussion of the clutch type fasteners used to attach most modern metallic insignia and familiar to most collectors of 20th Century insignia.When using fasteners to date an insignia there is a risk that someone might have previously removed the original fasteners and replaced them with ones from a different time period.In postwar helmets sand is used to texturize the surface instead of cork.
During the war the focus was on producing a volume of insignia to meet the nation's needs.That office closed in 1940 and London was replaced by Chicago.If you know these details contact staff who can order the relevant patent from our offsite store. When ordering this item, the Library staff will need to include the patent number and the date (it is optional to include patent title and patentee's name).In the 19th Century metallic insignia were attached by wire prongs or loops.In the 1890s the first screw back insignia appeared.