The Spring-Jaw Bodkin: A Grip That Holds Through Every Gather

"This invention has for its object to provide a new and improved bodkin of that type having at one extremity a pair of jaws for gripping a cord, tape, or ribbon which is to be inserted, laced, or similarly applied to fancy work or other articles." Two "flat elastic plates" are riveted together at the penetrating end; the rest of them "constitute a pair of spring-jaws, which by their inherent elasticity spring apart to their open position". Their ends are turned into flanges, "preferably toothed or serrated to afford a more secure gripping action", and a slide moves "in such manner as to release the jaws or to close them upon the cord, tape, or ribbon." The plates "gradually converge to a blunt penetrating extremity", and are "made of such thin and elastic material as to afford little or no obstruction to the convenient use of the instrument".

Sew a casing along one edge of a strip of cotton fabric by folding it over and stitching, leaving the ends open. Grip a length of elastic cord in the bodkin, tie the far end of the elastic to the force meter, and draw it through. Read the pull with the casing flat, then gathered up to half its length, then as tight as it will go. Compare how the pull grows with the notebook. Try a ribbon and a round cord, and note which the jaws lose first.

**Emma A. Willard** of Greenwich, Fairfield County, Connecticut, filed US 471,926 on 13 October 1891; it is dated 29 March 1892. She contrasts it with bodkins whose jaws telescope into the body and need a separate lock. **Honest limits.** The capstan rule assumes each gather is a clean bend with one friction coefficient; real casings are softer and uneven. Friction and wrap are examples. Your force readings are the measurement.