Lloyd Groff Copeman

Summary

Lloyd Groff Copeman (1881–1956) was a prolific Michigan inventor, credited by his family with nearly 700 patents, among them the flexible rubber ice cube tray (US 1,879,602, filed 1928) and early electric-stove and automatic-toaster designs; his Copeman Electric Stove Company, formed in Flint in 1912, was absorbed by Westinghouse in 1918. Family accounts say the ice-tray patents grossed about half a million dollars in royalties, but that late in life his patent income had ended: he sold the family farm, applied for Social Security, and left an estate of about $100,000.

Focus areas: Invention · Household technology · Michigan

At a glance

Field

Invention · Household technology

Location

Flint, Michigan

Correction: the ice-tray fortune

It is sometimes said that Copeman died a multimillionaire on the strength of the ice cube tray. Family-source evidence says otherwise: the tray grossed about half a million dollars in royalties, but his patent income ended within his lifetime — he sold the family farm, applied for Social Security, and left an estate of about $100,000.

References · in priority order

1. US 1,879,602 — Flexible sharp freezing containerpatents.google.com/patent/US1879602A/en
2. Family biography (lloydcopeman.com)www.lloydcopeman.com/biography/bio3.html

Sources

• Lloyd Groff Copeman is identified as an American inventor, 1881-1956, associated with the electric stove and flexible ice cube tray.lloydcopeman.com (family archive)
• Copeman's grandson wrote that Copeman counted nearly 700 patents and named the electric stove, rubber ice cube tray, and automatic electric toaster among his best-known inventions.lloydcopeman.com (family archive)
• Copeman Electric Stove Company was formed in Flint in 1912 and absorbed by Westinghouse in 1918.lloydcopeman.com (family archive)
• US1879602A, Flexible sharp freezing container, names Lloyd G. Copeman as inventor, was filed 1928-06-20, and published 1932-09-27.Google Patents
• A family account says the rubber ice tray grossed about half a million dollars in royalties, but that late in life Copeman had sold the family farm, applied for Social Security, and left an estate of about $100,000.lloydcopeman.com (family archive)