Patent ID: 6318416
Filing Date: 2001-11-20
Classification: A47C,B21F

Abstract:
A method for manufacturing, for an interior spring mattress or for cushioned furniture, a spring interior having a plurality of rows arranged parallel to one another and each including a plurality of individual springs each having end windings of the same diameter and produced from wire of the same diameter and same material, with different springs of a plurality of said rows having inner windings lying between the two end windings thereof having differing mean winding radii, and with a plurality of said rows having said different springs being arranged next to one another to form zones of differing hardness within the spring interior, the method comprising the steps of:forming a plurality of rows of springs of a spring interior;for each of the rows of the spring interior:automatically controlling a spring forming machine to successively coil individual springs of the row having end windings of the same mean radii, and while changing, from one spring to another spring in the course of coiling the springs of the row, the mean radius of one or more inner windings between two end windings to change the spring constant from one spring to another spring along the row in accordance with a predetermined stiffness pattern to produce a row of springs of differing spring constants arranged in a sequence in which they are coiled on the spring coiling machine,transferring the row of the springs as arranged in the sequence, and thenjoining the successively coiled arranged sequence of individual springs together in a row;following the forming for each of the rows of springs of the spring interior, controlling an automatic spring interior assembly machine to connect the plurality of rows of joined springs to one another to form a spring interior that includes the plurality of rows of springs interconnected in a predetermined rectangular array having differing stifness regions, at least a plurality of the rows of which include springs having inner windings of differing radii and therefore of differing hardnesses but having end windings equal radii; andthe formed springs having a central winding, and an inner winding between each end winding of the spring and the central winding, and the coiling step includes the step of changing, from one spring to another, the mean radius of an inner winding lying between the central winding and an end winding of the springs.