Method and apparatus for the manufacture of pocketed springs

In an apparatus for making a series of pocketed springs individually contained in pockets defined between two plies of a strip of sheeting by the spaced transverse seaming of said plies, wherein the apparatus includes:

• a support,
• closely spaced walls on said support defining between said walls a planar path for the movement of said strip longitudinally thereof through the apparatus along said path,
• drive means on said support engageable with said strip to advance the strip along said path,
• a spring inserter on said support for depositing axially compressed springs between the plies of said strip with their axes perpendicular to said plies and in spaced relation longitudinally of said strip,
• longitudinal seaming mechanism on said support for joining the edges of said plies together upstream of said drive means to form a sleeve about said compressed springs, and
• transverse seaming mechanism on said support for defining said pockets within said sleeve between successive transverse seams,
• the improvement wherein:
• said closely spaced walls and the plane of the path therebetween are vertical and the movement of the strip along said path is horizontal,
• the spring inserter includes a delivery chute positioned between the plies of the strip and having therein a reciprocable plunger to transfer into said strip between said plies a spring compressed into said chute,
• said apparatus includes on said support an upwardly-open horizontal spring-receiving trough communicating with said chute, and aligned therewith a reciprocable plunger for delivering and compressing into said chute a spring reposed in said trough, and
• interlocking control means to operate said inserter plunger only upon and during the presence of a fully compressed spring in said chute and thereafter to retract both plungers for the receipt by said trough of another spring.

The method of producing individually pocketed springs in continuous strips, comprising the steps of:

• advancing a two-ply longitudinally-folded strip of sheeting in regular motion longitudinally of the strip,
• inserting axially compressed springs between said plies in spaced succession with the ends of said springs engaged with said plies and with the spring axes perpendicular thereto,
• maintaining the compression of the springs of the springs between said plies through a predetermined length of travel of said plies to a release point,
• seaming the edges of said plies together before the release point is reached so as to form a sleeve about said compressed springs,
• making a transverse seam across said sleeve at a predetermined distance along said sleeve beyond said release point sufficient to allow a released spring to expand within said sleeve and against said plies to separate the plies,
• said sleeve being flattened to its full width by the formation of said transverse seam with said seamed ply edges incorporated into said transverse seam between the ends of said transverse seam,
• repeating the transverse seaming of said sleeve behind and alongside said expanded spring in spaced relation to said first-mentioned transverse seam to form a pocket enclosing the expanded spring therein with the seam of said edges positioned between the ends of the expanded spring, and defining a space within the sleeve for the expansion therein of the next spring to traverse said release point, and
• thereafter repeating said transverse seaming of said sleeve as aforesaid behind each successive spring released from compression by the advancing movement of said strip.

In a method of making pocketed springs in a connected series thereof, wherein said springs are compressed axially and inserted between the two plies of a longitudinally folded strip of sheeting which conveys said springs by regular longitudinal advancing movement of said strip along a confining planar path of predetermined length in which the compression of the springs is maintained, and the strip is made into a sleeve after the insertion of said springs by seaming the edges of said plies,

• the improvement which comprises:
• flattening said sleeve by a transverse seam perpendicular to the plane of said path and spaced from the end of said path to provide an enclosed space between said plies into which a spring can expand,
• releasing each spring seriatim from compression at the end of said path for expansion into said enclosed space in the sleeve as the sleeve advances, and
• repeating said transverse seam behind and alongside each newly expanded spring to enclose said spring within a pocket in which the sleeve-forming seam is incorporated into each said transverse seam between the ends of the spring in said pocket.

The method of producing individually pocketed springs in continuous strips, comprising the steps of:

• advancing a two-ply longitudinally-folded strip of sheeting in regular motion longitudinally of the strip,
• inserting axially compressed springs between said plies in spaced succession with the ends of said springs engaged with said plies and with the spring axes perpendicular thereto,
• maintaining the compression of the springs between said plies through a predetermined length of travel of said plies to a release point,
• seaming the edges of said plies together before the release point is reached so as to form a sleeve about said compressed springs,
• allowing the springs to expand within the sleeve as they successively pass said release point to separate said plies and position the edge seam of the sleeve between the ends of the springs and generally perpendicular to the axes of the springs, and
• making transverse seams between adjacent expanded springs and perpendicular to said edge seam to form pockets in the sleeve each containing an expanded spring.

In a method of making pocketed springs in a connected series thereof, wherein said springs are compressed axially and inserted between the two plies of a longitudinally folded strip of sheeting which conveys said springs by regular longitudinal advancing movement of said strip along a confining planar path of predetermined length in which the compression of the springs is maintained, and the strip is made into a sleeve after the insertion of said springs by seaming the edges of said plies,

• the improvement which comprises:
• flattening said sleeve by a transverse seam perpendicular to the plane of said path and spaced from the end of said path to provide an enclosed space between said plies into which a spring can expand,
• releasing each spring seriatim from compression at the end of said path for expansion into said enclosed space in the sleeve as the sleeve advances, and
• making transverse seams between adjacent expanded springs and perpendicular to said sleeve-forming seam to form pockets in the sleeve each containing an expanded spring.