A cover layer (23) of a fleece material for an innerspring unit (20) comprising a plurality of pocketed springs (29) is manufactured by supplying at least two longitudinal fleece webs (24, 25), which extend substantially parallel in a longitudinal direction and are spaced from one another, and repeatedly attaching a transverse fleece web (26, 27), which extends between the longitudinal fleece webs (24, 25) in a direction substantially perpendicular to the longitudinal direction, to the longitudinal fleece webs (24, 25). The transverse fleece web segments (26, 27) are attached to the longitudinal fleece webs (24, 25) such that they form together with the longitudinal fleece webs (24, 25) a framelike structure (21) serving as the cover layer (23).

In order to manufacture an innerspring unit (31) comprising pocketed springs and having an increased stability at its edge regions, in a first step, an innerspring main body (30) comprising a plurality of first strings (14) of pocketed springs is provided. In a subsequent second step, at least one second string (13c, 13d) of pocketed springs is attached to a lateral surface of the innerspring main body (30), so that the at least one second string (13c, 13d) of pocketed springs extends in a longitudinal direction of the innerspring main body (30). The springs (13) of the at least one second string (13c, 13d) of pocketed springs have a spring characteristic or a spring geometry different from the springs of the plurality of first strings of the innerspring main body (30). The at least one second string (13c, 13d) of pocketed springs forms together with the innerspring main body (30) the innerspring unit (31).

A system for manufacturing a string of pocketed coil springs comprising: a coil-forming subsystem that produces two coil springs; a spring transporter subsystem that receives the two coil springs at a first position and conveys the two coil springs to a second position; a spring compressor subsystem that compresses the two coil springs; a fabric-folding subsystem that receives a piece of fabric and folds the fabric to create an open side; a spring inserter subsystem that receives the two compressed coil springs and inserts the two compressed coil springs between top and bottom surfaces of a folded piece of fabric; two welder subsystems that form first and second welds between top and bottom surfaces of the folded piece of fabric, the first welds and the second welds forming a plurality of pockets in the fabric, each of the plurality of pockets comprising a compressed coil spring.

A system for manufacturing a string of pocketed coil springs comprising: a coil-forming subsystem that produces two coil springs; a spring transporter subsystem that receives the two coil springs at a first position and conveys the two coil springs to a second position; a spring compressor subsystem that compresses the two coil springs; a fabric-folding subsystem that receives a piece of fabric and folds the fabric to create an open side; a spring inserter subsystem that receives the two compressed coil springs and inserts the two compressed coil springs between top and bottom surfaces of a folded piece of fabric; two welder subsystems that form first and second welds between top and bottom surfaces of the folded piece of fabric, the first welds and the second welds forming a plurality of pockets in the fabric, each of the plurality of pockets comprising a compressed coil spring.

A system for manufacturing a string of pocketed coil springs comprising: a coil-forming subsystem that produces two coil springs; a spring transporter subsystem that receives the two coil springs at a first position and conveys the two coil springs to a second position; a spring compressor subsystem that compresses the two coil springs; a fabric-folding subsystem that receives a piece of fabric and folds the fabric to create an open side; a spring inserter subsystem that receives the two compressed coil springs and inserts the two compressed coil springs between top and bottom surfaces of a folded piece of fabric; two welder subsystems that form first and second welds between top and bottom surfaces of the folded piece of fabric, the first welds and the second welds forming a plurality of pockets in the fabric, each of the plurality of pockets comprising a compressed coil spring.

In order to manufacture an innerspring unit comprising pocketed springs and having an increased stability at its edge regions, in a first step, an innerspring main body comprising a plurality of first strings of pocketed springs is provided. In a subsequent second step, at least one second string of pocketed springs is attached to a lateral surface of the innerspring main body, so that the at least one second string of pocketed springs extends in a longitudinal direction of the innerspring main body. The springs of the at least one second string of pocketed springs have a spring characteristic or a spring geometry different from the springs of the plurality of first strings of the innerspring main body. The at least one second string of pocketed springs forms together with the innerspring main body the innerspring unit.