Abstract: The spring core for a mattress consists of several, identically formed spring coils arranged in side by side rows with each row forming a wire piece having an upper and a lower mutually aligned end spiral in a U-shape, and having opposite legs joined together by a base webb. Adjacent coil springs are joined together at their end spirals along abutting legs by helical connecting springs. To arrange the springs at tight angles in rows and columns, a length of one leg is greater than the length of another leg and all the coil springs are oriented in the same direction, except along a edge region of the spring core.

Abstract: A spring core comprises a plurality of coil springs 10 each made of a single, continuous piece of wire having two open ended final windings 11 which are approximately U-shaped. The coil springs are held together by spiral shaped connecting elements 30 enclosing the straight lateral arms 12, 13 of the final windings.