robert_leth is spot on. The patent (see pdf attached below) was applied for by Henry Handschur on November 27, 1935. At that time patents were good for 17 years (this was subsequently changed to 20 years in 1995), so the OP's humidor would have been made between the very end of 1935 and late 1952, assuming that the patent number would have been removed from humidors manufactured after that date (this is a reasonable assumption, but entails another conversation). There is a requirement that the clock starts running earlier if prior patent applications are referenced, which is the case in the Handschur patent, but given that these earlier attempts were abandoned I don't think this would apply; an attorney versed in IP would have to opine.
As a matter of minor curiosity there were two Henry Handschurs, father and son. Both were listed in various censuses as carpenters but by 1940 were identified as cabinet makers who worked together in the eponymous firm Handschur & Son. I should say that the father who immigrated with his family, Frank Handschur, is listed quite early as a cabinet maker so while they no doubt practiced general carpentry cabinet making was the family trade for at least three generations.
Henry the older (1877-1959) emigrated with his father Frank (1840-1926), mother, and siblings from what was then the Bohemia (i.e. Czech-Slovak) part of the Austro-Hungarian empire in 1888. In the New World he eventually married Annie Faltyn in 1900 and together they had four daughters and a son. The son, Henry William Handschur (1903-1989), married Sophie Urban in 1927 and together they had two sons.
Whether the patent was filed by the older Henry or the younger one is unclear to me; I could make a decent argument for either but honestly can't imagine the answer, if knowable, matters very much.