R.I.P. Trampoline
US registration 1943 · held generic in the United States in 1961
The story
George Nissen started building the bouncing rig in 1935, and from 1941 ran the partnership Griswold & Nissen with Larry Griswold. Nissen registered TRAMPOLINE (from the Spanish trampolín) at the USPTO on 7 August 1943, registration no. 402,868. Gyms, schools and the US military bounced the word straight into the dictionary, and when a competitor was sued, the court found circus and vaudeville performers had already been using it generically since the early 1900s. Held "completely generic for the type of goods here involved", registrations cancelled: Nissen Trampoline Co. v. American Trampoline Co., 193 F. Supp. 745 (S.D. Iowa 1961).
The moral
Fun fact: Nissen once promoted it by bouncing with a live kangaroo. The kangaroo did not save the trademark.
One grave, one country. Genericide is decided jurisdiction by jurisdiction and class by class: the same word can be the generic name of a product in one country and a live registered mark for the same goods in another. What is described here is the United States.