# Lloyd Groff Copeman

Lloyd Groff Copeman (December 28, 1881 – July 5, 1956) was an American inventor who devised the first electric stove and the flexible rubber ice cube tray, among other products. He had nearly 700 patents to his name, and he claimed that he could walk into any store and find one of his inventions.

## Early life

Copeman was raised by his Canadian parents, Caroline Estelle (née Groff) and John Wesley Copeman, on a farm in Hadley Township, Michigan which was later incorporated into Farmers Creek, Michigan, approximately 20 miles east of Flint, Michigan. He studied engineering at the former Michigan Agricultural College, now Michigan State University.

## Career

Copeman began his career as an apprentice at the Baldwin Locomotive Works in Philadelphia. Following that, he worked for electric utilities companies in Philadelphia and Spokane, as well as Detroit Edison and Consumers Power where he learned about electrical, marine and mechanical engineering, as well as steam fittings.
His first successful patented inventions, patented in 1909, were 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 US 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 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 The invention of the pop-up toaster in 1926 superseded Copeman's innovations, however.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 bought for $178,000 by the Alemite Manufacturing Corporation, the same corporation that also owned the patent rights to the Zerk fitting); Flexo-Line travel 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

Copeman married Hazel Dawn Berger, 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 daughter, Ruth Mary Copeman Ronstadt, was the mother of recording artist Linda Ronstadt.

## Patents

| March 11, 1909 | U.S. patent 1,055,446 | Thermostat and thermometer |
| August 5, 1913 | U.S. patent 1,069,531 | Electric switch |
| July 28, 1914 | U.S. patent 1,104,718 | Time-operating mechanism for electric switches |
| August 25, 1914 | U.S. patent 1,108,552 | Toast turner |
| August 25, 1914 | U.S. patent 1,108,553 | Toast turner |
| August 25, 1914 | U.S. patent 1,108,554 | Toaster |
| October 6, 1914 | U.S. patent 1,113,154 | Safety device for electrically heated cooking apparatus |

### 1915-1919

1915
Electrical heating unit. No. 1,138,733; May 11
Electromagnetic switch. No. 1,141,174; June 1
Electric stove. No. 1,141,175; June 1
Electrically heated oven. No. 1,141,176; June 1
1916
Automatically controlled electrical cooking apparatus. No. 1,180,571; April 25
Collapsible grease-capsule. No. 1,190,382; July 11
1917
Grease-cup. No. 1,222,185; April 10
1918
Grease-cup. No. 1,269,159; June 11
Grease-cup. No. 1,287,889; June 11
Drill. No. 1,264370; April 30
Grease-cup. No. 1,287,889; December 17
1919
Grease-cup. No. 1,294,773; February 18
Grease-cup. No. 1,300,699; April 15
Adjustable thermometer. No. 1,312,834
Grease-cup. No. 1,292,594
Grease-cup. No. 1,314,073; August 26
Shank and handle. No. 1,314,078; August 26

### 1920-1929

1920
Heating apparatus. No. 1,336,552; April 13
Adjustable thermostat. No. 1,349,364
Toaster. No. 1,356,042; October 19
Tool holder. No. 1,361,021; December 7
1921
Refrigeration apparatus. No. 1,396,996
Grease-cup. No. 1,368,546; February 15
Grease-cup. No. 1,395,336; November 1
1922
Refrigerating apparatus. No. 1,409,283; March 14
Refrigerating apparatus. No. 1,415,992; May 16
Refrigerating apparatus. No. 1,430,153; September 26
Refrigerating apparatus. No. 1,430,154; September 26
1923
Refrigerating apparatus. No. 163,419; July 31
Refrigerating apparatus. No. 1,472,266; October 30
Refrigerating apparatus. No. 1,472,267; October 30
Refrigerator. No. 1,444,589; February 6
1924
Refrigerator latch. Re. 15,908; September 2
Refrigerator latch. No. 1,489,918; April 8
Refrigerator door construction. No. 1,503,486; August 5
Refrigerator lining. No. 1,509,932; September 30
Casting and plastic materials. No. 1,515,150; November 11
Casting stone. No. 1,518,254; December 9
Water control for refrigerating system. No. 1,519,757; December 16
Refrigerating apparatus. No. 1,517,534; December 2
1925
Refrigerating apparatus. No. 1,526,964; February 17
Wall construction. No. 1,526,965; February 17
Molding the shells of refrigerators. No. 1,538,467; May 19
Casting refrigerator doors. No. 1,538,467; May 19
Refrigerator. No. 1,538,469; May 19
Collapsible molding dies. No. 1,538,471; May 19
Refrigerator construction. No. 1,542,862; June 23
Refrigerator. No. 1,548,825; August 11
Bushing construction. No. 1,564,947; December 8
Refrigerator doors. No. 1,564,948; December 8
1926
Refrigerator manufacture. No. 1,570,617; January 26
Refrigerator construction. No. 1,574,868; March 2
Refrigerator. No. 1,603,905; October 19
Refrigerator apparatus. No. 1,585,016; May 18
1927
Refrigerator construction. No. 1,644,981; October 11
Drinking water supply for refrigerators. No. 1,618,514; February 22
Water cooler. No. 1,633,372; June 21
Match-plate pattern. No. 1,644,968; October 4
Refrigerator. No. 1,644,983; October 11
Refrigerator. No. 1,644,984; October 11
Refrigerator manufacture. No. 1,644,985; October 11
Refrigerator construction. No. 1,644,986; October 11
Refrigerator. No. 1,644,987; October 11
Cabinet construction and building the same. No. 1,644,988; October 11
1928
Sharp freezing container for mechanical refrigerators. No. 1,675,599; July 3
Refrigerator cabinet and controlling the temperature therein. No. 1,618,398; August 21
Table top construction. No. 1,656,422; January 17
Method and apparatus for accelerating setting of stone castings. No. 1,656,423; January 17
Making match plate patterns. No. 1667,720; May 1
Stone mold. No. 1,667,721; May 1
Match plate pattern. No. 1,667722; May 1
Table top construction. No. 1,667,723; May 1
Container for power refrigeration. No. 1,671,761; May 29
Cooling unit for refrigeration apparatus. No. 1,671,762; May 29
Refrigerating cabinet and controlling and operating the same. No. 1,681,399; August 21
Refrigerator or cabinet. No. 1,692,159; November 20
1929
Balloon construction. No. 1,714,097; May 21
Sharp freezing container for mechanical refrigerators. Re. 17,278; April 23, Re. 17,279; April 23
Table top construction. No. 1,700,155; January 29
Making stone castings. No. 1,700,156; January 29
Table. No. 1,701,529; February 12
Refrigerating device. No. 1,703,299; February 26
Artificial stone refrigerator and forming the same. No. 1,703,511; February 26
Refrigerator cabinet. No. 1,710,405; April 23
Refrigerating apparatus. No. 1,710,406; April 23
Method and apparatus for forming and maintaining sanitation in ice cream cabinets or the like.
No. 1,711,721; May 7
Storage compartments for ice cream cabinets or the like. No. 1,711,722; May 7
Flexible sharp freezing container. No. 1,740,919; December 24

### 1930-1939

1939 Refrigerating unit. No. 1,744,038; January 21
Method of refrigerator manufacture. No. 1,757,450; May 6
Water cooler. No. 1,771,433; July 29
Sharp freezing container. No. 1,777,483; October 7
Refrigerator cabinet. No. 1,777,786; October 7
Refrigerator. No. 1,777,787; October 7
Refrigerating unit of fired ceramic material. No. 1,781,778; November 18
Method and apparatus for positioning and sealing ice cream cans in ice cream cabinets.
No. 1,786,827; December 30
1931
Ice cream cabinet. No. 1,789.587; January 20
Sharp freezing container for ice cream cabinets. No. 1,807,587; June 2
Dispensing unit embodying mechanical refrigerator. No. 1,811,456; June 23
Sharp freezing unit. No. 1,816,211; July 28
Refrigerating unit. No. 1,816,638; July 28
Sharp freezing container. No.1,817,544; August 4
Sharp freezing container. No.1,817,545; August 4
Refrigerating apparatus and heat transfer therein. No. 1,818,673; August 11
Unit formed partially of fired ceramic material. No. 1,822,013; September 8
Apparatus for controlling the temperature of unit containers. No 1,824,535; September 22
1932
Sharp freezing unit. No. 1,839,651; January 5
Refrigerating system. No. 1,840,619; January 12
Refrigerating system. No. 1,840,702; January 12
Cooling chamber for mechanical refrigerating unit. No. 1,872,685; August 23
Method and apparatus for freezing liquids. No. 1,878,685; August 23
Flexible sharp freezing container. No. 1,879,602; September 27
Refrigerating unit. No. 1,879,922; September 27
Sharp freezing structure. No. 1,882,209; October 11
Method and apparatus for refrigerating. No. 1,887,580; November 15
1933
Refrigerating apparatus. No. 1,902,016; March 21
Cooling unit. No. 1,912,826; June 6
Cooling unit construction. No. 1,912,827; June 6
Mold construction for reproduction of patterns in rubber. No. 1,913,747; June 13
Clothespin. No. 1,916,556; July 4
Closure member and forming and applying. No. 1,916,857; July 4
1934
Refrigerating system. Re. 19,055; January 16
Storage and dispensing unit for frozen foods. No. 1,952,422; March 27
Treating fruit or other growing vegetable matter. No. 1,955,950; April 24
Waterproof and puncture-proof paper. No. 1,976,329; October 9
1935
Refrigerator structure. No. 2,002,339; May 21
Method and apparatus for cooling beer. No. 2,010,060; August 6
Protective coatings and applying and removing. No. 2,020,256; November 5
1936
No patents
1937
Protective coating and applying and removing. No. 2,082,791; June 8
Bucket and bucket protector. No. 2,071,112; February 16
Dispensing device for sheet rubber deposited from an aqueous dispersion of rubber and forming the same. No. 2,075,178; March 30
Device for making and storing ice. No. 2,088,840; August 3
Method and apparatus for conditioning and dispensing beer. No. 2,075,088; October 19
1938
Concrete or cement structure. No. 2,112,452; March 29
Apparatus for handling ice cubes. No. 2,113,014; April 5
Refrigerating structure. No. 2,114,996; April 26
Protecting and forming pre-finished metal. No. 2,120,461; June 14
Protective coating and process of applying and removing. No. 2,132,230; June 14
Package structure. No. 2,134,908; November 1
1939
Bird shelter. No. 2,151,010; March 21
Mounting bracket. No. 2,184,633; December 26
Dispensing device for sheet rubber deposited from an aqueous dispersion of rubber and forming and using same. Re. 21,065; May 2
Protective coating and applying and removing. No. 2,169,225; August 15
Coating knit articles and products thereof. No. 2,172,251; September 5
Portable beverage conditioning and dispending apparatus. No. 2,182,116; December 5
Coating knit articles and products thereof. Re. 21,269; November 21

### 1940-1949

1940 Bird feeding station. No. 2,216,511; October 1
Birdhouse. No. 2,219,297; October 29
Cigarette and treating the same. No. 2,185,293; January 2
1941
Suet Cake container. No. 2,235,959; March 25
Flour sifter combination. No. 2,252,701; August 19
Container for confections. No. 2,248,963; July 15
1942
Collapsible birdhouse. No. 2,292,614; August 11
Birdhouse construction. No. 2,295,891; September 15
Treating textile fabrics and the products thereof. No. 2,281,830; May 5
1943
Clothesline. No. 2,318,275; May 4
Dispensing and using rubber. No. 2,307020; January 5
Closure member and applying same. No. 2,356,825; August 29
1945
No patents listed
1946
No patents listed
1947
No patents listed
1948
No patents listed
1949
Cream separator. No. 2,477,863; August 2
Apparatus for dispensing ice cubes. No. 2,484,017; October 11

### 1950-1957

1950
Ice tray. No. 2,514,476; July 11
Hand tool for agriculture implements. No. 2,528,947; November 7
1951
Method and apparatus for the manufacture of cigarettes. No. 2,543,277; February 27
1952
Spill guard for ice tray. No. 2,593,106; April 15
1953
Tractor hitch. No. 2,627,423; February 2
Bottle closure. No. 2,634,012; April 7
1954
2,688,236; Cl. 62-108.5
(Kisselle-ice tray grid) 2,671,321; March 9
1955
2,712,666; Cl. 15-142
2,704,732; Cl. 117-155
1956
Copeman, Lloyd Groff deceased; Elizabeth Jane (Betty), Gerlach, executrix Portable beverage conditioning and dispensing apparatus. No. 2,749,719; June 12
Cl. 62–91.5
1957
Moisture impervious container. No. 2,781,159; February 12
Cl. 229-16