Return to Index Making Chuck Springs by George Langford, Sc.D. February 2, 2009; copyright 2009 Henry Hjorth
patented a spring-winding tool in 1907, many of which find their way
into the antique tool market. I've recently been commissioned to make a
set of springs for a late-model Millers Falls No.2 eggbeater drill, so
I took the occasion to document how it's done. There are no
instructions on the use of the Hjorth spring winder tool published anywhere on the Internet, so I took advantage of Google's Patent Search
feature to find the best instructions of all. However, the PDF
file that Google provides is difficult to read, and the US Patent
Office's patent images are in a non-standard TIFF format, so I employed
optical character recognition to make a browsable version of the text
from Google's PDF version of the patent, and I used The Gimp's
ability to open and edit PDF images to condense the patent drawings
into JPG format as shown below. The DATAMP (Directory of American Machinery and Tool Patents) site has some additional history on this tool and the Hjorth patent.
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