SPRINGS.

Press, Volume LXIII, Issue 19150, 5 November 1927, Page 9

SPRINGS.

| A MODERN DEVELOPMENT. Springs, which are so vital to tlje modern automobile, are a comparatively modern development in the vehicular held. Steel springs first came into use about the year 1670. The earliest known device developed for casing the .strain of riding uwr rough roads was a leather thoroughbrace, which first appears in history in JSD2. The carriage body was hung on four of these large leather .straps, which to a slight degree softened the jolts over poor roads. The next improvement was to fasten the tops of these leather straps to fiexib-le, vertical posts. These were in reality the first "springs." The vertical posts were next built of steel, which allowed greater flexibility. In 1801 tho first semi-elliptic spring made its appearance. This type of spring is bolted at its centre to the axle. Each end of the spring is attached to the frame of the car. This type of spring remains to-dav the most popular.

A recent investigation disclosed that out of all American manufacturers, only three now make their own E-prinjis. In the manufacture cf every shipment of steel is analysed chemically to ensure proper composition. Before assembly each spring, leaf must be hcat-treatc-d and then is .shaped and tempered in a large steel drum revolving, in a tank of oil carrying several sets of huge steel jaws. Next it goes into a strong solution of hot salt water, which toughens the metal to a marked degree. Before assembly every'spring is tested to make sure that it is not too hard and brittle, nor too soft and yielding. When assembled the flexibility' of each ■spring is tested on a huce scale which shows how many pounds of pressure are necessary to press the curved spring flat.- Sets of two springs • are then picked out, having the same flexibility, and these go to the front or rear of the same car, ensuring equal results on the car.