Needle Bearings

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In 1925, Georg Hoffmann, a technician, patented a rolling bearing employing long, slender rollers—what in the U.S. has come to be called a "needle bearing."

It got that name in the most direct way possible: Early producers of such bearings, such as the Torrington Company in Torrington, Connecticut, and Durkopp in Germany, were originally makers of needles for sewing machines. Like bearing rollers, such needles must be strong, hard and precise.

Elias Howe invented a mechanical sewing machine in 1846, but for the most part, users had to improvise suitable needles for the next 20 years. Then, in 1864, Hopson and Brooks made inventions under the concept of a wire-pointing-and-compressing machine and, in 1866, the Excelsior Needle Company was organized in Torrington. Through WWI, that company manufactured a variety of items, such as wheel spokes and surgical needles. Then, in the Great Depression of 1929, engineer Edmund Brown was charged with dreaming up new products that the company could produce. His creation was a way of trapping needle rollers in a thin outer race whose ends were crimped over the pointed ends of the needles, holding them in place.

A few years earlier, Georg Hoffmann had patented a needle bearing in Europe, which was in 1930 produced by the French Nadella company. Brown's needle bearing found a lot of applications, some of which were in the B-29 bomber of WWII.

Germany's ball-bearing town, Schweinfurt, had been heavily bombed in that war, but in 1947, there was a world-wide rolling-bearing shortage brought about in part by Germany's absence from the market. INA, a company that had entered business in 1946 making wood carts, saw an opportunity. In 1949, it invented a needle-bearing "unit cage," which made it possible for a production-line worker to pick up a cage-and-roller assembly from a box and slip it onto a shaft. No more manually sticking dozens of rollers in place with grease and hoping they stayed put during assembly. Small projections on the cage were crimped to hold the rollers in place. In 1952, Volkswagen adopted INA's invention in its transmissions—and prosperity beckoned. INA went on to develop similar unit needle-bearing assemblies for the new two-stroke motorcycles that were everywhere.

—Kevin Cameron