ITT has acquired numerous other companies over time, including several switch and keyboard manufacturers. 2000 saw the acquisition of switch maker C&K. In 2007, ITT sold off their entire switch division to form C&K Components, with this new company combining not just C&K but also Rudolf Schadow and Jeanrenaud.
Subsidiaries of interest include the following:
ITT Jennings (seemingly acquired by ITT in 1961) advertised at least two series of switches stated to be for keyboards: JTFB and JTFR. These types were possibly intended only for calculators; the historic ambiguity of the word “keyboard” makes this hard to determine.
ITT acquired Californian keyboard manufacturer Datanetics in 1979. ITT operated Datanetics for a brief period of around 1979–1982 until the subsidiary was closed in favour of moving the products that interested them to their existing ITT Schadow subsidiary in Minnesota. The remaining product lines at Datanetics were sold off.
Rudolf Schadow GmbH was at some point acquired by ITT; they were responsible for the ETL18 keyboard switch.
Datanetics’ two lines of mechanical keyboard switches—DC-50 and DC-60—were transferred to ITT Schadow in Minnesota following the closure of ITT Datanetics.
ETL18 is a mechanical switch series branded as “ITT” and marked as being made in West Germany. German patent 3140199 covers this series; it was filed by Rudolf Schadow GmbH in October 1981. A label on a carton of 100 switches provided by Ellison Electronics—who carry surplus switches in stock—shows that the switches in question were manufactured by ITT Schadow in Germany in March 1993.
Virtually no details have been recovered for this series, and the switches are not commonly encountered. They have been found in one or two control panels, as well as one of the keyboard types used with the Interact Model One computer. The writing on the switches appears to say “ETL 18” with a space, but they are universally referred to as “ETL18” including by surplus parts stockists.
In most cases, the basic momentary switch is encountered. eBay listing 303950204739 “5 x ITT ETL18 Schalter” depicts not only the momentary type, but also a model that appears to be alternate action illuminated. The rear left corner of the switch appears to have a vertical spring for the alternate action mechanism, and there appears to be a metal pin between this assembly and the plunger. The far right corner appears to have a facility for attaching an LED (rather than a lamp, as one of the positions is denoted positive).
The triangle+circle logo on the switch is that of Schadow, as shown in an IEE advertisement in Electronic Engineers Master 1971–72, volume 2, pages 1922–25:
There is virtually no trace left of Rudolf Schadow itself, and the company is overshadowed by the German sculptor of the same name, after whom the manufacturer may have been named.