Method of making spring core for a bedding or seating product

A method of making a spring core for a bedding or seating product, comprising:

• providing a pair of border wires and a plurality of identically configured coil springs each made of a single piece of wire having a central spiral portion defining a central spring axis and terminating at opposing ends with unknotted upper and lower end turns disposed in planes substantially perpendicular to the spring axis, each of said upper and lower end turns being substantially U-shaped and having a first leg and a second leg joined by a connector having a bump, each of said end turns terminating in a free end, said first leg being at the free unknotted end of one of said end turns and the second leg being at the free unknotted end of the other of the end turns, the connector of one of the end turns being on the opposite side of the central spiral portion than the connector of the other end turn,
• arranging the coil springs in side-by-side rows and columns, and
• connecting adjacent coil springs at the upper and lower end turns of the coil springs by helical lacing wires to form a spring core, the coil springs being oriented the same direction in the spring core except every other one of the coil springs of the outermost columns of the spring core,
• securing the coil springs of the outermost columns to only one of the border wires.

A method of making a spring core for a bedding or seating product, comprising:

• providing a pair of border wires and a plurality of identically configured coil springs each made of a single piece of wire having a central spiral portion defining a central spring axis and terminating at opposing ends with unknotted upper and lower end turns disposed in planes substantially perpendicular to the spring axis, each of said upper and lower end turns being substantially U-shaped and having a first leg and a second leg joined by a connector having a bump, each of said end turns terminating in a free end, said first leg being at the free unknotted end of one of said end turns and the second leg being at the free unknotted end of the other of the end turns, the connector of one of the end turns being on the opposite side of the central spiral portion than the connector of the other end turn,
• arranging the coil springs in side-by-side rows and columns, and
• connecting adjacent rows of coil springs at the upper and lower end turns of the coil springs by helical lacing wires to form a spring core, the coil springs being oriented the same direction in the spring core except some of the coil springs of the outermost columns of the spring core,
• securing the outermost coil springs of each row to only one of the border wires.