Lloyd Groff Copeman

Is your surname Copeman?

Research the Copeman family

Share your family tree and photos with the people you know and love

  • Build your family tree online
  • Share photos and videos
  • Smart Matching™ technology
  • Free!

Related Projects

Lloyd Groff Copeman

Death: July 05, 1956 (74)
Immediate Family:

Son of John Wesley Copeman and Caroline Estelle Copeman
Husband of Hazel D. Copeman
Father of Lloyd Berger Berger Copeman; Ruth Mary Ronstadt and Elizabeth Jane Gerlach

Managed by: Private User
Last Updated:

About Lloyd Groff Copeman

American inventor Lloyd Groff Copeman had nearly 700 patents to his name. He invented an early form of the toaster, many refrigerator devices, the grease gun, the first electric stove, and an early form of the microwave oven. His flexible rubber ice cube tray earned him millions of dollars in royalties. You can walk into any store and find one of his inventions.

He was born on December 28, 1881. Copeman was raised by his Canadian parents on a farm in Hadley Township, Michigan which was later incorporated into Farmer's Creek, Michigan - located approximately 20 miles east of Flint, Michigan. He studied engineering at the former Michigan Agricultural College, now Michigan State University.

His first successful patented inventions, in 1909, were the following: an electrothermostatic heat regulator for more effective control of stove and toaster heating elements, and a thermostat for high-tension power cables.

Before this, while working for the Washington Electric Company in 1906, Copeman developed a design for an electric version of the gas stoves which had been available in Britain and the USA for several decades. Development of the idea took several years, but in 1912 the Copeman Electric Stove Company was formed in the city of Flint, Michigan to produce the Copeman Electric Stove (also marketed as the "fireless cooker"). Westinghouse Electric Corporation bought the company in 1917, moved production to Mansfield, Ohio, and continued to develop and improve the stove.

From 1913, another of Copeman's inventions, a toaster with automatic bread turner, was also produced by the Copeman Electric Stove Company. Electric toasters were a recent invention at that time - the first commercially successful version was patented in July 1909 - and the bread had to be turned manually once the first side had been toasted. During a shopping trip, Copeman's wife Hazel gave them the idea for a toaster which turned the bread without manual intervention, and in 1914 a patent for what Copeman called the Automatic Toaster was filed in Hazel's name. Five other toaster-related patents were granted to both Lloyd and Hazel during the same year. The invention of the pop-up toaster in 1926 made Copeman's innovations redundant, 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 bought for $178,000 by the Alemite Manufacturing Corporation, the same corporation that also owned the patent rights to the Zerk fitting); Flexoline clothes lines, which are still manufactured today; a device to use dry ice to cool bottles of beer; self-extinguishing cigarettes; and a rust-reducing latex coating for motor vehicles.

Copeman's most successful and remunerative invention, however, was the rubber ice cube tray. One day in 1928, while walking through some woods collecting sap for maple syrup, he noticed that slush and ice flaked off his rubber boots easily, rather than adhering to them. Having recalled this incident over lunch with his patent attorney, he conducted experiments using rubber cups, and later set about designing and then patenting different types of tray: a metal tray with rubber separators, a metal tray with individual rubber cups, and a tray made completely of rubber. Sales from this invention earned Copeman approximately $500,000, equivalent to $10 million today.

Personal Life

He married Hazel in 1904 and they had three children: Lloyd Berger Copeman (1907–1968), Ruth Mary Copeman Ronstadt (1914–1982), and Elizabeth Jane Copeman Gerlach (1918–1998).

His granddaughter, Linda Ronstadt Linda Ronstadt], is a legendary recording artist - who has been awarded a record 10 Grammy Awards to date - as well as one of the biggest-selling female singers of all time. Linda's mother was Ruth Mary Copeman Ronstadt, Lloyd's daughter.

Source: Wikipedia

view all

Lloyd Groff Copeman's Timeline

December 28, 1881
June 7, 1917
Flint, Genesee County, Michigan, United States
July 5, 1956
Age 74