Nothing to do with the Sheldon company that made metal-turning lathes from the early 1930s, this was a business started in the last years of the 19th or early years of the 20th century. Based originally in Chicago, early products included vices for woodworking and woodworking benches--the latter something that they specialised in until the 1970s with a vast range offered of many types and styles. A catalog showing their products can be downloaded from Vintage Machinery.org By the time of a move to Muskegon, in Michigan, they were also specialising in laboratory equipment for schools and colleges. By 1910 - and possibly earlier - Sheldon started to list wood-turning lathes, but it is not known if they were the manufacturer or just an agent or retailer. The company was purchased by American Seating of Grand Rapids, Michigan in the mid-1960s and operated as a separate subsidiary until at least 1976 - before being absorbed into American Seating.
The lighter lathes were of an unusual and interesting design, their beds consisting of two polished steel bars arranged one above the other. The only similar arrangement known to the writer is the English EXE 2.5-inch metal lathe, from the 1930s, where the lower round bracing bar was replaced by one of rectangular section.
The Sheldon range of wood lathes included simple, bench-mounted models for amateur and educational use and ones with treadle drive or equipped with an ingenious clutched/braked built-on countershaft unit. Larger lathes were also listed, these appearing to be of a conventional design with heavy, cast-iron beds and incorporating the improved clutch and brake countershaft described below.
All the twin-bar bed lathes had plain 'babbit" bearings with the bench-mounted ones available as the Model 1A with an 11-inch swing and taking 26 inches between centres, or as the long-bed Model 3A that took 36 inches. Both lathes were likely to have been driven by the maker's No.10 ceiling-mounted, tight and-loose countershaft unit with a belt striker to engage the motion and drive by an electric motor. These two models were also available on stands as "Foot-power Speed Lathes" on treadle stands - in which case they became, respectively, the Models 1 and 3. In the UK a "foot power" unit referred to a particular type of indented drive, like these, sold by Portass.
Another option was for the lathes to be mounted on cast-iron 'standards' - as legs were sometimes called - and fitted with the maker's "improved clutch and brake" drive system. Although details are scare, the unit appears to have been some form of cone clutch operated by a 6-inch diameter expanding ring in steel to grip the inside surface of a cast-iron flywheel. As the whole assembly would have had a considerable moment of inertia when running at top speed, a brake was provided by leather-lined shoes. From where did the power come? Presumably an electric motor via a wall-mounted countershaft..