Thomas by Gardner Denver: Our history since 1948

History Thomas


Gardner Denver, a US based company, founded in 1859, was acquired by KKR and the company taken private. The company was restructured into three major and distinct operating units - Industrial, Energy, and Medical Groups.

The brands Thomas, Welch and Ilmvac, with significant focus on Medical OEM and Laboratory Science applications formed the Gardner Denver Medical group. The group develops and manufactures relatively small compressors, gas and liquid pumps and modules for the medical, laboratory, environmental and numerous other demanding markets. Organizing these three brands in the Medical Group allowed us to align the business processes and development efforts to our customer needs.


Gardner Denver acquired Thomas Industries, a manufacturer of systems, compressors, vacuum pumps, liquid pumps and OEM pumps in the medical, laboratory, environmental and industrial sector, as well as Welch Vacuum Technology, a manufacturer of an innovative range of vacuum pumps, modular systems and network solutions for use in laboratory (laboratory vacuum pumps) and industry (industrial vacuum pumps).


Thomas Industries, Inc. announced another major acquisition of Werner Rietschle GmbH + Co. KG, one of the world's leading manufacturers of precision-engineered pumps and compressors, creating Rietschle Thomas.


In the company's 50th year, Thomas Industries and the Genlyte Group entered into a joint venture, creating Genlyte Thomas Group LLC.


Thomas Industries, acquired Welch Vacuum Technology to create a new presence in the laboratory market for deep vacuum flow control devices.


Thomas realigned its operating divisions into two groups and defined a long-range goal of concentrating on its two core businesses: Lighting and Compressors/Vacuum Pumps. Non-core businesses were divested.


Thomas entered into a joint venture with ASF GmbH & Co KG, a major player in air compressor and vacuum pump technologies.


Thomas Industries got the patent US 3.961.868 for a breakthrough innovation, the WOB-L pump technology.


Thomas continued to diversify its product lines, acquiring companies that manufactured a wide range of products from paint brushes to central vacuum systems.


Thomas Industries' stock began trading on the New York Stock Exchange.


Thomas Industries acquired the Benjamin Electric Company and C&M Products of Canada.


Thomas Industries Incorporated moved its headquarters to Louisville, Kentucky.


The first investor to further build the foundation for the todays Medical Group was Lee B. Thomas who acquired in 1948 a company from the Moe family that produced inlighting systems. He built Thomas Industries in 1953 with numerous acquisitions and reorganizations. The scope of the company moved from lighting to spray systems, leak detection systems and finally to the still available unique portfolio of different pump technologies.