The Spring-Prong Looper: Two Springs That Take the Loop Off the Hook and Hold It Open for the Needle

In a chain-stitch machine for leather with a hooked needle rising from below, the loop must be taken off the hook and held open so the needle passes through it on the next stroke, and a slide over the hook frays the thread. Edward E. Bean of Boston received US 28,144, dated 8 May 1860, for a looper that "consists of two flat springs, d d, and is seen particularly in Figs 9 and 10, the former of which represents the looper with its prongs sprung together, and the latter as it appears when opened by the needle." On a sliding bar below the table, it advances between the threads, rises to lift the loop from the hook, and carries it beyond the needle's path; on the next rise the needle forces the prongs apart and passes through the extended loop. This rung works out the force the needle needs to spread the prongs, then makes a spring-prong looper on a slide, and forms a chain of loops with it and a crochet hook.