METHOD OF PACKAGING A SPRING UNIT

Abstract: A method of packaging a spring unit (10) of plural coil springs (20) for use in a mattress in which first (26) and second (28) webs of spring insulator material are fixedly located against the top (12) and bottom (14) surfaces of a spring unit (10). The longitudinal margins (36, 38) are either respectively folded around the top (22) and bottom boils (24) and secured to itself, or matched up with the respective margin of the opposite web and secured to it by ultrasonic welding, bonding, etc. The spring units (10) are then compressed by roll-packing (60) so as to substantially reduce the shipping volume.

Description: METHOD OF PACKAGING A SPRING UNIT Field of the Invention This invention relates to the packaging of springs. More specifically, this invention relates to a method of roll-packing plural spring units. Background of the Invention It is known in the art to pack spring units for use in making mattresses by winding a length of flexible web material, e.g., disposable paper or re-usable hessian around a mandrel and feeding the spring units successively into the nip between the growing roll and the traveling web material. The spring units are compressed as they are drawn into the roll, and the result is that the roll-packed springs have a much reduced volume as compared to conventionally stacked spring units. One type of machine known for this purpose has a winding mandrel to which a holding bar is bolted by its ends for holding the leading end of a packing web material. An upwardly moveable pressure roller is mounted above the mandrel so as to define therewith an entry nip for the web material. The web material is fed from a reel supported at the rear of the machine over the pressure roller and on to the mandrel. An operator standing at the front of the machine feeds springs into the entry nip. Another machine for packing bedding springs is seen in U.S. Patent No. 4,669,247. The '247 patent describes packing spring units into a roll with a web of paper or other reusable material. A similar spring packing machine is seen in U.S. Patent No. 2, 1 1 4,008, in which a roll of wrapping paper is fed along a table and into a wrapping mechanism whereat spring assemblies are placed upon the paper and fed into the machine by the paper movement. All of these prior art machines compress and wrap springs in a single web of paper or reusable material which separates the multiple layers of spring units in a roll and maintains the springs in a compressed state for shipment from a spring manufacturer to a mattress manufacturer. This conventional roll packing technique tends to be expensive. Either large amounts of paper that will be eventually disposed of are used to wrap springs at a cost to the spring manufacturer which is often passed on to the mattress manufacturer, or much more expensive recyclable packaging is used to roll and ship springs. The recyclable material which is used to roll and ship springs must be thereafter shipped back to the spring manufacturer who, again, may incur the cost of shipping back the material and may pass that expense on to the mattress manufacturer. In addition, recyclable spring packaging material has a relatively short life span, albeit longer than paper packaging. Objectives of the Invention Therefore, it has been one objective of the present invention to reduce the cost of packaging and shipment of spring units. It has been another objective of the present invention to provide a method of packaging spring units without using conventional paper or reusable packaging methods. It has been a further objective of the present invention to provide a method of packaging a spring unit in which the spring unit is packaged in insulator material that will not be disposed of but, rather, be used by the mattress manufacturer in mattress production. Summary of The Invention The preferred embodiments of the present invention accomplish these objectives with a method of packaging a resilient spring unit such as a plurality of interconnected coil springs in which first and second webs of spring insulator material are first attached to the spring unit so as to be located against the spring unit top and bottom surfaces and thereafter roll-packed for shipment from a spring manufacturer to a mattress manufacturer who simply unrolls the spring units and cuts the insulator material between the spring units, the spring units having the insulator material attached thereto to be used in mattress manufacture so as to eliminate the need to roll-pack the spring units with disposable paper or expensive reusable material. The spring unit has a uniform depth defined by a generally planar top first surface and a parallel generally planar bottom second surface. The spring unit has a longitudinal dimension or length defined by a pair of opposed parallel end surfaces and a transverse dimension or width defined by a pair of opposed parallel side surfaces. The longitudinal dimension or length is generally greater than the transverse dimension or width of the spring unit as in most bedding products. However, a square spring unit in which the longitudinal and transverse dimensions are equal may also be packaged using this inventive method. The method of the present invention comprises providing first and second web rolls of insulator material spaced from one another. The first web roll comprises a first web of spring insulator material, e.g., woven or non-woven material, wound about a core. Similarly, the second web roll comprises a second web of spring insulator material wound about a core. Each of the first and second webs of insulator material have a pair of opposed side edges defining a width of the web which is wider than the spring unit's transverse dimension. Each web across its width has a pair of opposed side portions and a central portion between the side portions. The first web of insulator material is passed over and located against the first surface of the spring unit, and the second web is passed under and located against the second surface of the spring unit. The longitudinal dimension of the spring unit is generally parallel to the opposed side edges of the first and second webs which are generally parallel to one another. In a first preferred embodiment, the first and second webs are folded back upon themselves around the top and bottom turns of the edgemost coil springs of the spring unit so that the opposed side portions are located against the surface of the central portion located against the spring unit. These side portions are then bonded, welded or otherwise secured to the central portion. In a second preferred embodiment, the side portions of the first web are bonded or welded to the adjacent side portions of the second web so as to form a tight fitting sleeve in which the spring unit is securely located. The spring unit with the first and second webs secured thereagainst constitutes a bedding product. The final step in the method of the present invention is to draw the bedding product into a roll packing machine in which the bedding product is compressed and rolled onto a dowel whereafter the bedding product is maintained in this rolled and compressed state for shipment to a mattress manufacturer. These and other objectives and advantages of this invention will be readily apparent from the following brief description of the drawings. Brief Description of the Drawings Fig. 1 is a perspective view of a first preferred embodiment of the present inventive method of packaging a resilient spring unit; Fig. 1 A is a cross-section of Fig. 1 taken along lines 1 A- 1 A; Fig. 2 is a side view of a bedding product being roll packed; Fig. 3 is a perspective view of a second preferred embodiment of the present inventive method; and Fig. 3A is a cross-sectional view of Fig. 3 taken along lines 3A-3A. Detailed Description of the Preferred Embodiment As can be seen generally in Figs. 1 , 1 A, 3, 3A, a spring unit 1 0 generally has a top or first surface 1 2 and a bottom or second surface 14. The spring unit 10 has a length or a longitudinal dimension L and a width or a transverse dimension D, the longitudinal dimension L being generally larger than the transverse dimension D. However, it will be appreciated by those in the art that L may be substantially similar to D in dimension. The spring unit 1 0 has a thickness T between the first surface 1 2 and the second surface 14 which defines opposing end surfaces 1 6a, 1 6b and opposing side surfaces 1 8a, 1 8b. The spring unit 1 0 is generally comprised of a plurality of coil springs 20, the coil springs 20 being secured one to another by means generally known in the art. Each coil spring 20 has a top turn 22 comprising a portion of the first surface 1 2 and a bottom turn 24 comprising a portion of the second surface 1 4. The first surface 1 2 and the second surface 1 4 are covered with first and second webs 26, 28, respectively, of insulator material. The insulator material used to cover the first and second surfaces 1 2, 1 4 of the spring unit 1 0 is generally a woven or non- woven material. Each of the first and second webs 26, 28 have an obverse side 30 and a reverse side 32, the reverse side 32 of each of the first and second webs 26, 28 being located against the first and second surfaces 1 2, 1 4 of the spring unit 1 0, respectively. As seen in Figs. 1 A and 3A, each of the first and second webs 26, 28 has a center portion 34 and opposed side portions 36, 38. Each of the first and second webs 26, 28 has a substantially similar width W larger than the transverse dimension D of the spring unit 1 0 so that the opposed side portions 36, 38 generally extend beyond the transverse dimension D of the spring unit 10 in substantially equal amounts. The lengths (not indicated) of the first and second webs 26, 28 are considerably longer than the longitudinal dimension L of a single spring unit 1 0 so that plural spring units 10 may be packaged by the inventive method described in further detail below. In the present inventive method of packaging a spring unit 1 0, the first and second webs 26, 28 are carried upon respective first and second cores 40, 42 which allow the first and second webs 26, 28 to be drawn therefrom in reverse directions as indicated by directional arrows 40a, 42a. The first and second webs 26, 28 are drawn between respective first and second guide rollers 44, 46, the rollers 44, 46 being spaced apart from each other so that spring unit 1 0 may be received therebetween. A conveyor 48 transports the spring unit 1 0 by directional arrow 48a into a space 50 defined between the first and second rollers 44, 46 whereat the first and second webs 26, 28 are passed over and under and located against the first and second surfaces 1 2, 1 4, respectively, of the spring unit 1 0. In a first preferred embodiment, after the first and second webs 26, 28 are located against the respective first and second surfaces 1 2, 1 4 of the spring unit 1 0, an adhesive unit 52 deposits adhesive 56 upon the reverse side 32 of the side portions 36, 38 of each of the first and second webs 26, 28. The spring unit 1 0 having the first and second webs 26, 28 located thereagainst is then passed to a folding unit 54 which folds the reverse side 32 of the side portions 36, 38 of each of the first and second webs 26, 28 with the adhesive 56 deposited thereon against the reverse side 32 of the respective center portion 34 and against the top and bottom turns 22, 24 of the coil springs 20 comprising the longitudinal margins of the spring unit 1 0. As seen in Figs 3 and 3A, in a second preferred embodiment, after the first and second webs 26, 28 are located against respective first and second surfaces 1 2, 1 4 of the spring unit 1 0, the spring unit 1 0 with the first and second webs 26, 28 located thereagainst is passed to a welding unit 58 whereat the reverse sides 32 of the opposed side portions 36 of the first web 26 are welded to the adjacent side portions 36 of the second web 28. While only side portions 36 of the first and second webs 26, 28 are shown in Fig 3A, it will be understood that side portions 38 are a mirror image thereof and are welded in a similar manner. The welding together of the first and second webs 26, 28 may be accomplished by any suitable welding process for woven or non-woven materials known in the art, e.g., ultrasonic or radio frequency welding, to create a weld 58a, as seen in Fig. 3A. After the first and second webs 26, 28 have been fixedly located against the first and second surfaces 1 2, 14 of the spring unit 1 0 by either the gluing or the welding methods as described above, the spring unit 1 0 with the first and second webs 26, 28 located thereagainst is then passed to a roll packing machine 60 as best seen in Fig. 2. The roll packing machine 60 has a plurality of rollers 62 which carry thereon an endless belt 64 traveling in a direction indicated by directional arrow 64a. The spring unit 1 0 with the first and second webs 26, 28 attached permanently thereto comprises a bedding or seating product 68 ready for shipment, for example, from a spring manufacturer to a mattress or seat manufacturer. As the product 68 is wound about a core 70 upon which it is to be transported, the roll packing machine 60 compresses the bedding or seating product 68 so that plural bedding or seating products 68 may be so packaged. When the packaged roll of bedding or seating units 68 arrive at the mattress or seat manufacturer's facility, all that the manufacturer need do is unroll the packaged products from the roll and transverse cut the webs 26, 28 at a location between the spaced spring units 1 0. The resulting bedding or seating product 68 having the insulator material permanently secured to its top and bottom sides is than ready for application of the appropriate padding and upholstry materials to complete the mattress or seat. From the above disclosure of the detailed description of the present invention and the preceding summary of the preferred embodiment, those skilled in the art will comprehend the various modifications to which the present invention is susceptible. Therefore, I desire to be limited only by the scope of the following claims and equivalents thereof. I claim:

Claims: 1 . A method of packaging a spring unit having a generally planar first surface and a parallel generally planar second surface, said method comprising the steps of: providing first and second webs of insulator material each having a generally uniform width, a pair of opposing side portions, a center portion, and obverse and reverse surfaces; locating said first and second webs against said first and second surfaces, respectively, of said spring unit; permanently securing said first and second webs against said first and second surfaces, respectively, whereby said spring unit with said first and second webs secured thereto constitutes a bedding product; and roll packing said bedding product. 2. The method of claim 1 , wherein said spring unit is comprised of a plurality of coil springs having top and bottom turns, the method comprising the steps of: folding each of said first and second web side portions around the adjacent said top and bottom coils, respectively, so that said reverse surface of each of said side portions is folded back upon said reverse side of said respective center portion; and securing said reverse side of said side portions to said reverse side of said respective center portion. 3. The method of claim 2, comprising the step of adhesively bonding said reverse side of said side portions to said reverse side of said respective center portion. 4. The method of claim 1 , further comprising the step of securing said reverse side of each of said side portions of said first web to the adjacent said second web side portion. 5. The method of claim 1 , further comprising the steps of: providing first and second web rolls carrying said first and second webs of insulator material, respectively; and passing said first and second webs of insulator material between respective first and second rollers before passing said first and second webs over said first and second surfaces, respectively, of said spring unit. 6. A method of packaging a spring unit, said spring unit having a generally planar first surface, a generally planar second surface, a longitudinal dimension and a transverse dimension, said method comprising the steps of: providing first and second web rolls of insulator material, each of said web rolls comprising a web of insulator material carried upon a core, each of said webs of insulator material having obverse and reverse sides, and opposed side edges defining a width of said web, said width being larger than said spring unit's transverse dimension, each of said webs having opposed side portions and a central portion between said side portions across said width of said web; passing said first and second webs of insulator material transversely past said first and second surfaces, respectively, of said spring unit, said spring unit being oriented such that said transverse dimension of said spring unit is generally perpendicular to said opposed side edges of said webs; locating said first and second webs against said first and second surfaces, respectively, of said spring unit so that each of said opposed side edges of each of said first and second webs extend beyond said transverse dimension of said spring unit; securing said first and second webs to said spring unit so that said reverse sides of said central portion of each of said first and second webs lay against said first and second surfaces, respectively of said spring unit, whereby said spring unit with said first and second webs secured thereto constitutes a bedding product; and roll packing said bedding product. 7. The method of claim 6, wherein said spring unit is comprised of a plurality of coil springs, each having a top turn and a bottom turn, the method further comprising the steps of: folding said side portions of each of said first and second webs around the adjacent said top and bottom turns, respectively, of said coil springs which comprise margins of said spring unit along said spring unit's longitudinal dimension so that said reverse surface of said side portion is folded back upon said reverse side of said respective center portion; and adhesively bonding said reverse sides of each of said side portions of each of said first and second webs to said reverse side of the respective said central portion of each of said first and second webs. 8. The method of claim 6, further comprising the steps of: locating said reverse side of one of said first webs' side portions against said reverse side of the adjacent said second webs' side portion; and welding said first web side portion to the adjacent said second web side portion. 9. The method of claim 6, further comprising the step of passing said first and second webs of insulator material between parallel rollers before passing said webs past said first and second surfaces of said spring unit. 1 0. The method of claim 9, wherein said parallel rollers rotate in opposite directions as said webs are being passed past said spring unit. 1 1 . The method of claim 6, wherein said web rolls rotate in opposite directions as said webs are being passed past said spring unit. 1 2. A method of packaging a spring unit, said spring unit having a generally planar first surface, a generally planar second surface, a longitudinal dimension and a transverse dimension, said spring unit being comprised of a plurality of coil springs each of which having a top turn and a bottom turn, said method comprising the steps of: providing first and second web rolls of insulator material, each of said web rolls comprising a web of insulator material carried upon a core and each of said webs of insulator material having obverse and reverse sides and opposed side edges defining a width of said web, said web being wider than said spring unit's transverse dimension, each of said webs having opposed side portions and a central portion between said side portions across said width of said web; passing said first and second webs of insulator material transversely past said first and second surfaces of said spring unit, respectively, said spring unit being oriented such that said transverse dimension is generally perpendicular to said opposed side edges of each of said webs; locating said first and second webs against said first and second surfaces, respectively, of said spring unit so that each of said opposed side edges of each of said first and second webs extend beyond said transverse dimension of said spring unit; folding said side portions of each of said first and second webs around said top and bottom turns, respectively, of said coil springs that comprise the margins of said spring unit along said spring unit's longitudinal dimension so that said reverse side of each of said first and second web side portions is folded back upon the respective said first and second web center portion; bonding said reverse sides of said side portions of each of said first and second webs to said reverse side of said central portion of each of respective said first and second webs, whereby said spring unit with said first and second webs secured thereto constitutes a bedding product; and roll-packing said bedding product whereby said spring units are substantially compressed. 1 3. A method of packaging plural spring units, each of said spring units having a generally planar first surface, a generally planar second surface, a longitudinal dimension, and a transverse dimension, said method comprising the steps of: providing first and second web rolls of insulator material, each of said web rolls comprising a web of insulator material carried upon a core, each of said webs of insulator material having obverse and reverse sides and opposed side edges defining a width of said web, said width being larger than said spring unit's transverse dimension, each of said webs having opposed side portions and a central portion between said side portions across said width of said web; passing said first and second webs of insulator material transversely past said first and second surfaces of said spring unit, respectively, said spring unit being oriented such that said transverse dimension of said spring unit is generally perpendicular to said opposed side edges of said webs; locating said first and second webs against said first and second surfaces, respectively, of said spring unit so that each of said opposed side edges of each of said first and second webs extend beyond said transverse dimension of said spring unit; locating said reverse side of said first web's opposed side portions against adjacent said side portion's reverse side of said second web; welding said first web side portion's reverse side to said second web side portion's reverse side, whereby said spring unit with said first and second webs secured thereto constitutes a bedding product; and roll-packing said bedding product whereby said spring units are substantially compressed. 1 4. A roll-packed bedding product comprised of a spring unit having first and second surfaces and first and second webs of insulator material fixedly located against said first and second surfaces, respectively, said spring unit being roll-packed and maintained in a compressed state when roll-packed.

Inventors: MOSSBECK NIELS S, MOSSBECK, NIELS, S.
Applicants: L & P PROPERTY MANAGEMENT CO, L & P PROPERTY MANAGEMENT COMPANY
Application year: 2000
Main classification: B65B63
IPC codes: B65B9, B65B63