 The invention of the pop-up toaster in 1926 superseded Copeman's innovations, however.A company called Copeman Laboratories Company had been established in Flint, Michigan during the year 1918 to allow Copeman to dedicate his time to inventing, although he also spent a lot of time at his farm in Farmer's Creek, where he would lock himself in the basement - sometimes for up to a week, with his wife bringing him meals on a tray  - and develop new ideas and products.Examples of his work at this time, which met with varying success, included injecting chickens with solutions to make their meat taste like beef; pioneering experiments in the development of latex; the Copeman Lubri-Cap, grease-filled paper cups for lubricating wheel bearings (the patent for this product was 

Copeman's most successful and remunerative invention, however, was the rubber ice cube tray.