Register :: Login
Manufacturers Index - Ridgway Dynamo & Engine Co.
This page contains information on patents issued to this manufacturer.

Submitting Patent Information

If you find a patent number or patent date by this manufacturer that is not on this list, please contact the Site Historian.

Key to Links for Patent Information

USPTO = U.S. Patent Office . Images of the actual patent can be viewed on the U.S. Patent Office web site but a special TIFF viewer must be installed with your browser in order properly work. More information on how to configure your computer to view these patents can be found at TIFF image Viewers for Patent Images.
DATAMP = Directory of American Tool And Machinery Patents . A sister site to VintageMachinery.org with information on patents related to machinery and tools. A much easier user interface than the USPTO's for finding information on machinery patents.

Patent Number Date Title Name City Description
603,475 May. 03, 1898 Cut-off mechanism for steam-engines John Stumpf Chicago, IL
1,045,630 Nov. 26, 1912 Unidirectional-flow steam-engine Johan Stumpf , Germany This is the first patent for the Stumps Uni-Flow steam engine. See patent 1,285,475 for more information.
1,285,475 Nov. 19, 1918 Automatic exhaust-valve Wolfgang Turnwald Syracuse, NY In the Stumpf Una-Flow Engine design, steam enters from either end of the cylinder, and the exhaust is at the mid-line of the cylinder. Steam enters alternately at either end of the cylinder. This interesting design was problematic in practice. For one thing, the cylinder experienced a temperature gradient—cool at the center and hotter and either end, which required the cylinder to be made with a slight taper to compensate. As well, the engine moved quickly, which stressed the valves and required the engine to be heavily built to withstand the stresses.
A 1922 condensed catalog from Ridgway Dynamo & Engine Co. lists "Unaflow Engine: Built under Stumpf patents. Steam jacketed heads, poppet valves and extremely simple valve gear. Bed, governor and reciprocating parts same as on Single Valve Engine. Recommended for high pressures, high superheat, and condensing service. Sizes 100 H.P. to 800 H.P."