Bedding and seating product having double twist coil spring and method and apparatus for manufacturing the same

A double twist bedding coil spring comprising

• a single length of wire having a middle section and a pair of end sections,
• the opposite ends of said middle section being located in a diametral plane of an end convolution of said coil, said pair of end sections of said wire being coiled in the same rotational direction from said opposite ends of said middle section of said wire and formed into a helix of increasing pitch extending from said end convolution over a major portion of the axial length of said coil springs toward an opposite end convolution of said coil spring.

A double twist bedding coil spring having one end convolution substantially located in a first plane and having a second end convolution substantially located in a second parallel plane spaced from said first plane, said coil spring comprising

• a single length of wire having a middle section and a pair of end sections, said middle section of said wire having a pair of opposite ends,
• said opposite ends of said middle section being located in a diametral plane of said one end convolution of said coil, said pair of end sections of said wire being coiled in the same rotational direction from said opposite ends of said middle section of said wire and formed into a helix extending from said first end convolution to said second end convolution,
• said end sections of said wire terminating in free ends, said free ends of said wire being located on opposite sides of said second end convolution.

A double twist bedding coil spring having one end convolution substantially located in a first plane and having a second end convolution substantially in a second parallel plane spaced from said first plane, said coil spring comprising,

• a single length of wire having a middle section and a pair of end sections, said middle section of said wire having a pair of opposite ends,
• said opposite ends of said middle section being located in a diametral plane of said one end convolution of said coil, said pair of end sections of said wire being coiled in the same rotational direction from said opposite ends of said middle section of said wire and formed into a helix extending from said first end convolution to said second end convolution, each of said end sections of said wire forming a single full revolution over an axial length in excess of three inches between said first and second convolutions.

A double twist bedding coil spring having one end convolution substantially located in a first plane and having a second end convolution substantially located in a second parallel plane spaced from said first plane, said coil spring comprising

• a single length of wire having a middle section and a pair of end sections, said middle section of said wire having a pair of opposite ends,
• said opposite ends of said middle section being located in a diametral plane of said one end convolution of said coil, said pair of end sections of said wire being coiled in the same rotational direction from said opposite ends of said middle section of said wire and formed into a helix of increasing pitch extending from said first end convolution over a major portion of the length of said coil spring toward said second end convolution.