| Name | Summary | Parent Co. | Child Co. | Is Base Co. |
|---|---|---|---|---|
| Columbia Time Products | A name Westclox used ca. the 1950s - 1960s on some private label or lower priced clocks. | No | ||
| Eastern Time Limited | Hong Kong, maker of clocks and movements for Westclox. Founded ca. 1964. | No | ||
| General Electric | Part owner of Warren Telechron Company. Marketed clocks with the General Electric name. | Telechron | No | |
| General Electric Telechron | Name used in the mid-1950s on clocks. | Telechron | No | |
| General Time Corporation | Holding company for Westclox and Seth Thomas starting in 1949. | General Time; Seth Thomas; Westclox | No | |
| General Time Instruments Corporation | Holding company for Westclox and Seth Thomas 1936 - 1949. | General Time; Seth Thomas; Westclox | No | |
| Plymouth | Name used by Seth Thomas in the 1930s - 1950s for a lower priced lines of clocks. | Seth Thomas | No | |
| Regent Mfg. Co. | Chicago. Made cast front cases that often housed Western Clock Clock Manufacturing Company or Western Clock Company movements. | No | ||
| Revere | The Revere Clock Company, Cincinnati, Ohio, U.S.A. Made chime and strike clocks using Telechron motors. | Telechron | No | |
| Seth Thomas Clock Company | Before Seth Thomas was part of General Time | Seth Thomas | No | |
| Swartzbaugh | The Swartzbaugh Mfg. Co. Toledo, Ohio. Maker's name on the Everhot Appliance Timer made by Westclox. | No | ||
| Telechron Inc. | Telechron, Inc. ca. the 1950s | Telechron | No | |
| Timex | Brand of popular-priced wrist watches (and a few clocks). In 1922, Waterbury Clock Company purchased the Robert H. Ingersoll & Bro. company. In 1944, Waterbury Clock Co. was renamed U.S. Time Corp . . . | Waterbury Clock | No | |
| United Clock Company | Founded by Charles Stahlberg, et. al. in 1885. | Westclox | No | |
| United Time Products | A name Westclox used ca. the 1930s - 1950s on some private label or lower priced clocks. | No | ||
| Warren Clock Company | Henry Warren's first company | Telechron | No | |
| Warren Telechron Company | Henry Warren's second company | Telechron | No | |
| Westclox Canada Talley Industries | Westclox Canada, Talley Industries, a division of Talley Canada Inc. | Westclox | No | |
| Westclox Div. General Time Canada | Westclox Division General Time of Canada Limited; Peterborough, Canada. | Westclox | No | |
| Westclox Div. General Time Canada Talley | Westclox Division General Time of Canada Limited, A Talley Industries Company; Peterborough, Canada. | Westclox | No | |
| Westclox Division of General Time Corporation | Starting in 1949 | Westclox | No | |
| Westclox Division of General Time Instruments Corporation | This name used when General Time Instruments Corporation was formed in 1936. | Westclox | No | |
| Western Clock Company 1887 | Started in 1887. | Westclox | No | |
| Western Clock Company 1912 to 1936 | Starting in 1912 | Westclox | No | |
| Western Clock Company Ltd. Canada | Western Clock Company, Ltd., Peterborough, Canada | Westclox | No | |
| Western Clock Manufacturing Company | Starting in 1888 | Westclox | No | |
| Accurate Time Stamp Company | West Virginia. Some Stahlberg patents are assigned to this company. | Yes | ||
| A. L. Swift | Chicago. Name seen on dials of the cast iron stove clock. | Yes | ||
| American Cyanamid Company | Manufacturer of Beetle® and Melmac® molded plastics for clock cases, telephone housings, etc. Address given as PLASTICS DEPARTMENT, 34 Rockefeller Plaza, New York 20, N.Y. in a 1950 advertisement. | Yes | ||
| Ansonia | The Ansonia Clock Co. has its roots in Bristol, CT. Theodore Terry, nephew of Eli Terry, and F. C. Andrews formed the firm Terry & Andrews in 1841 to manufacture inexpensive brass movement clocks. The . . . | Yes | ||
| Arnex | Maker of reproduction watches with mechanical movements in the 1970s. | Yes | ||
| Bulova | Bulova Watch Company. Imported Swiss watch movements and cased them in the USA. | Yes | ||
| Catalin Corporation of America | Manufacturer of Catalin plastic used in clock cases. Address: One Park Avenue, New York 16, N.Y. in 1947 advertisement. | Yes | ||
| Chelsea | Chelsea Clock Company. Founded in 1884 as Boston Clock Company, became Chelsea in 1897. Well known for ship's bell clocks. Still making clocks in the USA. | Yes | ||
| Deemer Mfg. co. | Chicago, IL. Name on the back of the case iron stove clocks. | Yes | ||
| Dura Company | Toledo, Ohio, maker of cast cases such as the Westclox Dura Case models | Yes | ||
| E. Howard Watch Co. | Base company for E. Howard and Howard watches | Yes | ||
| Elgin | Made watches in the USA from 1864 to 1968. | Yes | ||
| General Time | This is the base company for General Time Instruments Corp. and General Time Corp. | General Time Corporation; General Time Instruments Corporation | Yes | |
| Gilbert | William L. Gilbert was born in 1806 in Northfield, CT (a village of Litchfield) and became interested in the booming clockmaking business at Bristol in 1828. In that year he and his brother–in–law . . . | Yes |
