1839, Jacob Pratt's Patent Model of a Silk Reeling, Spinning, and Twisting Machine

Reeling, Spinning, and Twisting Silk Machine Patent Model

Patent No. 1,367, issued October 12, 1839

Jacob Pratt of Sherborn, Massachusetts

Pratt is an example of an inventor who thought he had a more complicated original invention than he actually had. In his patent application file, his specification makes four claims. Out of those four, only one was approved by Charles M. Keller, the patent examiner, and that claim was for using a trough of zinc. The trough held spools of silk fibers prior to spinning and was filled with warm water, which kept the fibers from sticking together.

The Journal of the Franklin Institute, 1840, commented: “Its construction is, in general, similar to such as is well known, and is not claimed as new . . . No particular reason is given for making the troughs of zinc, and we suppose that copper would do equally well; but from the special mention of this metal we were led to look for some ground of preference to it.”

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