Koehring Company bought The Parsons Company in 1929, and it became one of a number of manufacturers affiliated in the National Equipment Corporation marketing group. The Corporation was dissolved just two years later, but Parsons remained a division of Koehring, and Parsons went on to produce a wide range of wheel and ladder trenchers. The Parsons name also appeared on KoehringТs Dumptors in the mid to late 1960s.
In 1976, Koehring divested itself of the Parsons division. The rubber-tired trencher line was sold to Seaman Corporation; early in 1977, Seaman closed the Parsons plant in Newton, Iowa, and moved the operations to Milwaukee, Wisconsin, under the Seaman Parsons Corporation name.Then, in January 1978, Seaman acquired the Digz-All Trencher Company Division of Wind-King Manufacturing Company. In 1992, Maxon Industries, Inc. purchased the trencher lines from Seaman and moved them to its own plant in Milwaukee; the Seaman-Maxon, Inc. name was used at least at the outset, but the Parsons trade name was used for the trenchers as of fall 2007.
The large wheel and ladder trenchers were sold to Trenchliner, a new company established in Austin, Texas, and named after the Parsons trade name for the machines. Trenchliner folded in 1980, and Michael Kukla International bought the line; while Kukla continues to build ladder trenchers today, the last machines from the Parsons lineage were produced in 1984.
Koehring Company acquired Schield-Bantam Company as a division in 1963. SchieldТs Bantam line of cable excavators was inspired by a Koehring 303 acquired by principal Vern Schield. The Thew Shovel Company was merged into Koehring in 1964 to become its Thew-Lorain Division. Bantam products continued until 1982, but the Lorain line was reduced by 1976 to the L790 crawler crane. Koehring sold the Lorain wheel loader line to Massey-Ferguson Ltd. in 1971.
Koehring acquired hydraulic component manufacturer Husco in 1968 as a subsidiary. It also acquired The Buffalo-Springfield Roller Company, which it sold to Bomag , and the C. S. Johnson Company. West Brick Buggy Corporation developed the Skytrak extended-reach forklift, and Koehring either acquired the product line of the company.
Koehring products were manufactured in England by Newton Chambers & Company under the NCK name. In 1974, it also had a licensing agreement with IHI Ц Ishikawajima Construction Machy Co. Ц Compact Excavator Sales.
As of 1974, Koehring owned or produced:
Х Schield Bantam truck crane, crawler crane, self-propelled hydraulic crane, truck hydraulic crane, crawler hydraulic backhoe and hydraulic log loader;
Х Koehring crawler hydraulic backhoe, crawler dragline and crawler crane;
Х Lorain truck crane, truck tower crane, self-propelled hydraulic crane, crawler hydraulic backhoe and crawler crane;
Х Koehring-Waterous pulpwood grinder, pulpwood harvester and crawler hydraulic backhoe;
Х Johnson Division (former C. S. Johnson Company) concrete batch plant, batch plant components, stationary concrete mixer, and slipform paver;
Х MKT (McKiernan-Terry) pile hammer, pile extractor, pile driving leads, demolition hammer, casing driver and vertical borer;
Х Master Division (Master Vibrator Company) plate compactor, concrete vibrator, power trowel, air tool, light plant, chain saw, screed, space heater and centrifugal pump; and,
Х Dart Division (Dart Manufacturing Company) concrete vibrator, power trowel and light plant.
In 1974, it also owned and operated a North American Compaction, Bomag Division (consisting of the Road Division [Buffalo-Bomag, former Buffalo-Springfield] roller, static compactor, landfill compactor, self-propelled stabilizer, self-propelled smooth vibratory compactor and Flaherty Manufacturing Branch of Buffalo-Springfield chip spreader; PCM Division concrete mixer, rough terrain forklift, extended reach forklift, Mud Jack slurry pump and Ka-Mo borer; Parsons wheel trencher and cable plow; and Speedstar Division water well drill); and Menck GmbH hydraulic backhoe, truck crane, electric cable shovel, pile driver, and Scrapdozer crawler motor scraper.
Amca International acquired Koehring in 1980 or 1981. Northwest Engineering Company acquired Koehring Crane & Excavator in 1987; after Northwest acquired Terex Corporation, the use of the Koehring , Lorain and Bantam trade names was discontinued.