Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47C—CHAIRS; SOFAS; BEDS
  • A47C27/00—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas
  • A47C27/04—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas with spring inlays
  • A47C27/05—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas with spring inlays with padding material, e.g. foamed material, in top, bottom, or side layers
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47C—CHAIRS; SOFAS; BEDS
  • A47C27/00—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas
  • A47C27/04—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas with spring inlays
  • A47C27/05—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas with spring inlays with padding material, e.g. foamed material, in top, bottom, or side layers
  • A47C27/053—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas with spring inlays with padding material, e.g. foamed material, in top, bottom, or side layers with only one layer of foamed material

Definitions

• the present invention relates to foamed innerspring units and, in particular, to a method of manufacturing foamed innerspring units wherein a flexible polyurethane foam is adhered directly to the innerspring and wherein adjacent springs are free of any supporting connection between each other other than the foam.
• foamed innerspring unit is intended to be construed in its broadest sense.
• foamed innerspring units include mattresses and box springs.
• a mattress is designed to provide support for a person sleeping thereon, while a box spring provides support for both the mattress and the person sleeping on the mattress.
• other types of “foamed innerspring units” such as cushions, car seats and the like can be provided in accordance with the invention and the term “foamed innerspring unit” is not intended to be limited only to mattresses and box springs.
• the innerspring unit loaded into the foamable reaction mixture of the '439 patent is an innerspring unit well known in the art since the coils of the innerspring unit, which is later exposed to the unique foaming process, are all interconnected with each other.
• innerspring units have been produced having coils which are interconnected with each other.
• Innerspring units are constructed by a variety of methods, all designed to form the individual coils into an assembly of coils of a prescribed shape and coil count.
• the coils are usually held together by spirals of wire known as "pigtails", clamped together by lengths of wire, or encapsulated into pockets of fabric forming long strips which are then attached to one another by sewing, gluing or hog ringing.
• the method of forming a foamed innerspring unit has been limited to use of an innerspring unit wherein the coils of the innerspring were securely bound to each other prior to exposure to a foaming process, which innerspring units inhibit flexibility in mattress design and increase the cost of mattresses.
• a method for producing a foamed innerspring unit in a discontinuous process wherein the coils of the innerspring unit are embedded into the surface of the foam so that adjacent coils are free of any supporting interconnection other than the foam comprises releasably mounting individual coils by their respective first ends onto a first jig, placing the first jig over a tray which contains the foamable reaction mixture so that the free second ends of the coils are suspended spaced from the bottom of the tray, and allowing the foamable reaction mixture to rise so that the second ends of the individual coils become embedded in the foam, separating the first jig from the first end of the coils and curing the foam or permitting the foam to cure.
• the method can include the further steps of spraying a releasing agent into a tray before applying the foam and applying the foam by spraying.
• the method can also include the further steps of removing the foam member which has the second ends of the coils embedded within it from the tray, releasably mounting the foam member onto a second jig with the free first ends of the coils projecting therefrom, positioning the second jig over a tray containing a foamable reaction mixture with the free first ends of the coils spaced from the bottom of the tray and allowing the foamable reaction mixture to rise so that the first ends of the individual coils baco e embedded into the foam.
• the method can still further include removing the second jig, curing the foam or permitting the foam to cure and removing the completed foamed innerspring unit from the tray.
• a foamed innerspring unit having a plurality of coils, adjacent coils being joined for relative positioning at each of their respective ends only by a layer of foam adhered to the coil ends is also provided.
• a foamed innerspring unit section formed of a plurality of coils, adjacent coils being joined for relative positioning at each of their ends only by a layer of foam adhered to the coil ends may be provided, permitting the construction of a mattress by assembling at least two of such mattress sections by a retaining means.
• the retaining means may include a mattress cover overlying and joining the mattress sections. The interior of the mattress cover may be compartmentalized to receive one or more mattress sections.
• the mattress sections or regions of a unitary foamed innerspring unit can be selected ,to have different degrees of firmness as by selection of the coils in each section or region.
• a further object of the invention is to provide a method of manufacturing a foamed innerspring unit at low cost.
• Another object of the invention is to improve the comfort of foamed innerspring units .
• Another object of the invention is to provide orthopedic qualities to the foamed innerspring unit.
• Another object of the invention is to provide an inexpensive, comfortable and safe foamed innerspring unit.
• a further object of the invention is to provide a foamed innerspring unit composed of a plurality of foamed innerspring sections to permit customizing the firmness of various locations in the mattress .
• the invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the articles possessing the features, properties and the relation of elements, which are exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims .
• FIG. 1 is a flow diagram showing the steps of one embodiment of the method of the invention.
• FIG. 2 is a perspective view of a foamed innerspring unit prepared in accordance with the invention.
• FIG. 3 is a cross-sectional view of the foamed innerspring unit taken through line 3-3 of Fig. 2;
• FIG. 4 is a perspective view of one embodiment of a tray used to prepare a foamed innerspring unit of the invention
• FIG. 5 is a cross-sectional view showing a foam spray used in the method of the invention as applied to the tray of FIG.
• FIG. 6 is a perspective view of the interior of a first jig in accordance with the invention with the first ends of the coils being held by magnets therein;
• FIG. 7 is a cross-sectional view of an alternate embodiment of the jig of FIG. 6 showing the first ends of the coils held in place by magnets, with the jig placed over a tray having a foamable reaction mixture therein with the free second ends of the coils above said mixture;
• FIG. 8 is a cross-sectional view of a partially prepared foamed innerspring unit in accordance with the invention, showing the risen foam adhered to the second ends of the coils in the tray;
• FIG. 9 is a cross-sectional view of an embodiment of a second jig supporting the partially prepared innerspring unit of FIG. 8 with the jig placed over a tray having a foamable reaction mixture therein with the free first ends of the coils above said mixture;
• FIG. 10 is a perspective view of an alternate embodiment of the tray in ace- .-dance with the invention having partitions dividing the tray irrco six sections;
• FIG. 11 is a perspective view of a foamed innerspring mattress made from the six foamed innerspring components in accordance with the invention and a partitioned mattress cover;
• FIG. 12 is an enlarged fragmentary cross-sectional view of the foamed innerspring components taken through line 12-12 of Fig. 11;
• FIG. 13 is a perspective view of a cover of an alternate embodiment of a mattress in accordance with the invention having six innerspring components in an alternate embodiment of a partitioned mattress cover;
• FIG. 14 is an alternate embodiment of the tray in accordance with the invention.
• FIG. 15 is a fragmentary cross-sectional view of the embodiment of the first jig placed upon the alternate embodiment of the tray of FIG. 14 having notches or ridges to support the ends of the coils; and O 95/21048
• FIG. 16 is an enlarged fragmentary cross-sectional view showing an alternate embodiment of a multi-section mattress in accordance with the invention having a cover without internal partitions .
• FIG. 1 wherein the process of the '439 patent is generally indicated, except that after the "spray foam batter" step a parallel conveyor 1 is provided by way of example in accordance with the present invention to perform specific loading steps so that an innerspring having a plurality of coils, adjacent coils being free of all interconnection for relative positioning other than the foam at their ends, is manufactured.
• Main conveyor 2 can perform the process of the '439 patent when the load unit step is performed suing a conventional spring assembly with adjacent springs joined to each other.
• the method can comprise the steps of: releasably mounting individual coils by their respective first ends onto a first jig; spraying a release agent into a tray; spraying a foamable reaction mixture, preferably but not necessarily formed from at least diphenylmethane diisocyanate and a polyol, that will provide a flexible foam into the tray; positioning the first jig, having the coils individually mounted by their first ends, over the tray which contains the foamable reaction mixture so that the second ends of the individual coils are suspended spaced from the bottom of the tray; permitting the foamable reaction mixture to rise to form a flexible foam adhered to the second ends of the coils; separating the first jig from the first ends of the coils; curing the foam or permitting the foam to cure; removing the foam member having the second ends of the coils embedded therein from the tray; releasably mounting the foam member having the second ends of the coils embedded therein onto a second jig; positioning the second jig over a
• the process of this invention can be used in conjunction with or in the alternative to the process disclosed in the '439 patent.
• a diverging second conveyor belt is depicted to perform the unique steps of the present invention, including releasably mounting the jigs with the coils or the partial innerspring unit and positioning jigs over a tray having a foamable reaction mixture therein.
• the second conveyor belt may then rejoin the main conveyor belt to complete the process as disclosed in the '439 patent.
• This arrangement permits innerspring units free of any interconnections between adjacent coils other than the foam and innerspring units as taught in the '439 patent having conventional innersprings where the coils are bound to each other to be reproduced alternatively on the same production line.
• the process of this invention is also well suited to having its own “permit foam to rise", “cure foam” "unload unit” and “clean tray” stations so that innerspring units having coils free of any interconnection between adjacent coils other than the foam can be produced on a single conveyor. Even where only a single conveyor is provided, provision can be made to produce both types of mattresses on the single conveyor.
• One advantage of the method in accordance with the invention is that the method can be applied on a discontinuous basis. Thus, the application of the second foam layer to the coils can occur at any time.
• the basic process in accordance with the '439 patent may be performed on a conveyor arrangement shown schematically with various steps performed at various locations along the conveyor arrangement.
• the first step of FIG. 1, pre ⁇ heating the tray is an optional step preferably used where the tray is formed of a metal such as steel.
• the tray is preferably formed of polyethylene, in which case, the pre-heating step may not be required.
• the process in accordance with the invention produces an innerspring unit 30 having a plurality of coils 20 connected to each other only by the two foam members 32 and 34, which capture and are secured to the respective ends of the springs in the region B of foam member 32 and B' of foam member 34.
• the height of the regions A of foam member 32 and A' of foam member 34 can be as thin as one-quarter to three-eighth inch above the height of the coil ends.
• Suitable release agents generally encompass long chain waxes dissolved in solvents.
• Suitable release agents include, but are not limited to, CHEM-TREND PRC 778 Registered TM manufactured by Park Chemical Co. , CHEM-TREND CT 1081 Registered TM and CHEM-TREND CT 1057 Registered TM, all manufactured by Chem Trend Corporation and HR 29 Registered TM manufactured by Green Chem Products.
• the foamable reaction mixture used in accordance with the invention is prepared using diphenylmethane diisocyanate and at least one polyol without preparation of a prepolymer.
• the isocyanate is a blend of 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate.
• the isocyanates are present in an amount of greater than about 80% 4,4 '-diphenylmethane diisocyanate and less than about 20% 2,4'-diphenylmethane diisocyanate.
• the blend includes greater than about 90% 4,4'-diphenylmethane diisocyanate and less than about 10% 2,4'-diphenylmethane diisocyanate.
• the average isocyanate functionality refers to the average number of NCO groups attached to each molecule. In a preferred embodiment, the isocyanate functionality is between about 2 and 2.8. More preferably, the isocyanate functionality is between about 2.1 and 2.3.
• the isocyanate equivalent weight refers to the molecular weight of an isocyanate molecule divided by the average isocyanate functionality. In a preferred embodiment, the isocyanate equivalent weight is between about 130 and 135.
• the viscosity of the isocyanate mixture is between about 35 and 100 centipoises at 20°C. This low viscosity is desirable for purposes of the invention.
• the polyol is a hydroxyl terminated copolymer.
• the polyol copolymer contains between about 14% and 20% ethylene oxide or propylene oxide and between about 80% and 86% of a polyether having a molecular weight of between about 4,000 and 6,000.
• a blowing agent such as water which reacts with the isocyanate mixture and provides carbon dioxide is required to foam the reaction mixture and this should be provided.
• Catalysts which accelerate the polyurethane formation and, optionally, auxiliaries and additives, which are commonly used for the manufacture of flexible polyurethane foam, can also be added to the foamable reaction mixture.
• auxiliaries and additives include, for example, surface-active materials, flame inhibitors, pore regulators, antioxidants, hydrolysis-protection agents, dyes, fillers and other additives .
• Suitable catalysts for accelerating the reaction between the polyols, the water, and optional chain-extension agents, on the one hand and the polyisocyanate mixture include tertiary amines such as dimethylbenzylamine , N , N , N ' , N ' -tetramethyldiaminodiethyl ether , bis-(dimethylaminopropy)-urea, N-methyl- or N-ethylmorpholine, dimethylpiperazine , 1 , 2-dimethylimidazole , 1-aza-bicyclo-(3,3,0)-octane, and preferably, triethylenediamine, metal salts such as lead octoate, tin, di-2-ethylhexanoate, and preferably, tin-(II) salts, and dibutyltin dilaurate, as well as, particularly, mixtures of tertiary amines and organic t
• Preferably used are 0.5 to 5 percent by weight catalyst based on tertiary amines and/or 0.01 to 2.5 percent by weight of metal salts, based on the polyol weight.
• siloxaneoxyalkylene mixed polymer and other organic polysiloxanes oxyethylated alkylphenol, oxyethylated fatty alcohols, paraffin oils, castor oil or ricinoleic ester, and turkey red oil, which are used in quantities of 0.2 to 6 parts by weight per 100 parts by weight of the polyisocyanate mixture.
• flame inhibitors can be added to the flexible polyurethane foams manufactured in accordance with this invention.
• examples are compounds containing phosphorus and/or halogen atoms which can also reduce the tendency toward brittleness of the products and function as plasticizers.
• tricresyl phosphate tris-2-chloroethyl phosphate, tris-chloropropyl phosphate and tris-2,3-dibromopropyl phosphate
• inorganic flame inhibitors such as antimony trioxide, arsenic oxide, ammonium phosphate, ammonium sulfate, and others, and preferably, cyanic acid derivatives such as cyanamide, dicyandiamide, guanidine, and in particular, guanidine salts, biguanidine, and particularly, melamine. It has generally proven to be advantageous to use 5 to 70 parts by weight, preferably 10 to 50 parts by weight, of the above-referenced flame inhibitors per 100 parts by weight of the isocyanate mixture.
• the polyol and the isocyanate are mixed in one step using suitable spray equipment.
• suitable spray equipment is the Gusmer automatic mechanically self-cleaning high pressure 95/21048
• the spray gun has two inlet ports, a mixing chamber and an outlet.
• One of the inlet ports is adapted to receive the polyol while the other is adapted to receive the isocyanate.
• a high pressure proportioner such as the model H-2000 high pressure proportioner also manufactured by Gusmer Corporation can be used to adjust the ratio of polyol to isocyanate entering the inlet ports.
• the polyol and isocyanate are mixed rapidly in the mixing chamber to form a foamable reaction mixture.
• the foamable reaction mixture is dispensed through the outlet in an appropriate pattern prior to the time the reaction mixture begins to foam.
• the spray equipment used to carry out the method of the invention is commonly used in the construction industry for manufacturing and spraying rigid foams, roof insulation, thin layer coatings and the like.
• the equipment is relatively inexpensive, portable, easy to handle and transport and mixes the components of the spray under high pressure. However, only one setting is available for each gun.
• Conventional high or low pressure mixing equipment for mixing flexible foams generally have variable settings so that the isocyanate equivalent weight can be adjusted as necessary by changing the pump speed.
• the spray equipment used to carry out the process of the invention places limitations on the chemistry.
• MDI chemistry proceeds using about a 1:1 ratio of isocyanate:polyol.
• the resulting foam has a density of between about 2.0 and 2.5 lbs/ft 3 , preferably, between about 2.0 and 2.2 lbs/ft 3 .
• foam prepared using TDI chemistry has a density on the order of about 1.2 lbs/ft 3 .
• a foam having a density of between about 2.0 and 2.5 lbs/ft 3 has about twice as much chemical composition per cubic foot of foam as a foam having a density of 1.2 lbs/ft 3 and, correspondingly, less air in the foam.
• Foams prepared in accordance with the invention are, therefore, 95/21048
• a foam having a density within the preferred range will provide a firm and comfortable mattress. Additionally, foams prepared using MDI chemistry do not have tough, inflexible skins on the side adjacent the tray.
• a dense foam of the type prepared in accordance with the invention will return to its original configuration or, at the least, nearly its original configuration after it has been compressed and the compression force has been withdrawn, i.e. the foam exhibits elastic deformation. This is a desirable characteristic for a foam used to prepare a foamed innerspring unit. Less dense foams exhibit plastic deformation and this is undesirable.
• the nozzle 16 of the specialized spray gun used in accordance with the invention sprays the foamable reaction mixture in a straight line fan pattern as shown in FIG. 5.
• the foamable reaction mixture is sprayed into the tray to an appropriate depth.
• the depth of spray is determined by the height that the foam is to be permitted to rise. In general, the foam rises to about five times the height to which it is sprayed.
• the spray pattern can be an oval pattern.
• the fan spray has a width of 24 inches. Accordingly, the spray gun is traversed over the tray in order to fill the tray to the predetermined depth.
• multiple spray guns can be used and, in a still further alternate embodiment, the spray gun can be maintained stationary and the tray can be moved as necessary. It is to be noted that the most difficult area to cover are the edges of the tray and accordingly, an especially heavy spray is required in these areas. This may be achieved by having a portion of the foam pattern impact on the sidewalls of the tray as shown in FIG. 5.
• torsion bars are usually provided in conventional mattresses in order to provide additional edge support.
• the torsion bars are arranged so that four are provided on each side and one on each end.
• edges can be built up laterally with foam so as to form a solid wall. This will provide continuous peripheral edge support and obviate the need for torsion bars.
• five passes of the spray gun are required for filling the tray for a queen size mattress to a depth of 3/16 inch thick of foamable reaction mixture. Additionally, 3/16 inch batter will approximately quadruple in volume to provide a 3/4 inch thick layer of foam.
• FIG. 4 One embodiment of a tray or mold cavity 10 of the type adapted to be used to make foamed innerspring units in accordance with the invention is shown in FIG. 4 and in cross-section in FIGS. 5 and 8.
• the tray differs from the tray of the '439 patent in that the stops or notches for limiting insertion of the springs and guides for centering are dispensed with.
• the size and shape of the tray is not critical and is determined by the size and shape of the unit to be provided. In general, trays can be provided for any type of foamed innerspring unit such as mattresses, box springs, car seats, cushions and the like.
• tray 10 has a flat bottom 12 which defines a rectangular area.
• Four perpendicular side walls 14 define sides of tray 10.
• the preferred embodiment is to spray the foamable reaction mixture into tray 10 having a flat bottom 12 and position coils 20 above the foamable reaction mixture layer so that the foamable reaction mixture rises and captures the ends of the coils.
• the free ends of the coils can be inserted in the foamable reaction mixture as it rises and before it sets and is cured.
• the coils 20 In order to carry oi.t the process of the invention, the coils 20 must first be releasably mounted on a first jig 22 as shown in FIG. 6, whir has a horizontal wall 23 and side walls 25 depending perpendicu. , ; commely from the horizontal w.-.,l 1 23.
• Jig 22 is formed of a metal which is magnetizable such as steel, and a plurality of permanent magnets 24 are secured to the outer surface of horizontal wall 23.
• a plurality of coils 20 are releasably held in prescribed positions on the inner surface of horizontal wall 23 in a desired pattern with a first end 20a of the coils 20 engaged against horizontal wall 23 and a second end 20b of the coils 20 being free and projecting into the space between side walls 25.
• FIG. 7 wherein the jig 22' with the coils independently mounted on the inner surface of horizontal wall 23 is shown.
• First ends 20a of the coils 20 are releasably secured to the inner surface of horizontal wall 23 of jig 22' by the magnetic attraction of magnets 24.
• magnets to secure the ends of the coils to the first jig 22' provides great versatility since the coils 20 can be easily maneuvered from one position to another and a variety of patterns of coils may be formed.
• the coils are aligned in straight rows using the magnet means.
• the magnet means can be used to position the coils in staggered formations or any desired alignment.
• Positioning indicators can be provided on the interior surface of horizontal wall 23 to simplify coil placement.
• the first jig 22 may be provided with releasable mechanical clamps at each coil position (not shown) for securing the ends 20a of the coils 20 so that the coils are clamped for mounting and released after the foam sets as a unit, individually and in groups.
• the advantages of using magnetic force to secure the coils to the first jig includes the flexibility of the selective positioning of the coils as desired.
• a pattern may be drawn on the inner surface of horizontal wall 23 of jig 22 so that not only specific positions such as staggered or row formations may be set, but the placement of coils with different gauges may also be predetermined. Since the thickness of the wire of a coil determines its ability to resist compression (degree of firmness), different gauge coils can be secured to the first jig in a predetermined pattern so that a mattress having selected degrees of firmness in different areas can be produced as desired. For example, the center region (viewed lengthwise) of a mattress may be of a greater firmness to support greater weight.
• the horizontal wall 23 of the first jig 22 is positioned above the tray 10 containing the foamable reaction mixture 26 so that the unattached second ends 20b of the coil are suspended spaced from the bottom of the tray having the freshly sprayed foamable reaction mixture 26 therein.
• This alignment is shown in FIG. 7 using a slightly different form of first jig 22, first jig 22', as more particularly described below, but still relying on the permanent magnets 24 to releasably hold coils 20 in position.
• the height of the side walls 25 of first jigs 22 or 22' is selected to correctly position the second free ends 20b of coils 20 relative to the bottom 12 of tray 10 when the side walls rest on the surface which supports tray 10.
• the foamable reaction mixture 26 is then allowed to rise and form a foam which embeds the second free ends 20b of the coils 20.
• the second ends 20b of coils 20 may be forced, in part, into the foamable reaction mixture as it rises or after it rises. This poses no problem since, at this point, the foamable reaction mixture is in a jel state and effectively grips the coil ends.
• a chemical reaction to produce the foam is over within 45-90 seconds depending on the foam selected.
• the first jig may be pulled off since the magnetic attraction between the coils and the magnet means is not strong enough to resist the holding force of the second ends 20b of the coil 20 embedded in first foam member 32.
• the clamps would now be released.
• the term set refers to at least a partial cure sufficient to permit adhesion of the foam to the coil ends .
• FIG. 8 shows the second ends 20b of coils 20 embedded in the first foam member 32 after it has set. Following the rising of the foam, the foamed coils are O 95/21048
• the partially foamed innerspring unit is turned over and the foam member 32, having the second coil ends 20b embedded within it, is subsequently mounted to a second jig so that the first ends 20a of the coils which were previously releasably attached to horizontal wall 23 of first jig 22 by magnetic force or clamping means, but which are now free, may, in turn, be loaded into a tray containing a foamable reaction mixture.
• FIG. 9 shows a second jig 28 which is provided with curved needles 30 of a desired length welded to the inner surface of horizontal wall 29 of second jig 28.
• the second jig 28 also has side walls 31 extending perpendicularly from the inner surface of the horizontal wall 29.
• the curved needles are provided for capturing the first foam member 32 which now has the second ends 20b of coils 20 embedded within it.
• the foamed portion of the partially made mattress is mounted onto the curved needles, being centered on horizontal wall 29 through the placement of appropriate markings on the inner surface.
• the horizontal wall 29 of second jig 28 is positioned over tray 10 containing the freshly sprayed foamable reaction mixture 26 so that the first ends 20a of the coils 20 are suspended spaced from the bottom of the tray containing sprayed foamable reaction mixture 26.
• the foamable reaction mixture is then permitted to rise to form a foam member 34 which captures and embeds the first ends 20a of the coils 20.
• the second jig 28 is removed (the holding force of needles 30 being insufficient to resist the holding force of the foam member 34 in tray 10) and the foam is then cured as above and removed from tray 10.
• the height of side walls 31 of second jig 28 is selected by positioning first ends 20a relative to the bottom of tray 10 as shown in FIG. 9.
• the second jig may have clamps (not shown) extending inwardly from the opposing side walls of second jig 28 which serve the function of 95/21048
• tray 10 can serve as the second jig since it releasably holds the first foam member 32 until forced to release same.
• a suitable spacer can be provided between the two trays 10 to provide the proper positioning of coil ends 20a.
• the first jig 22' of FIG. 7 is adapted to be modified to perform the function of the second jig 28 of FIG. 9 so that an entirely new second jig 28 need not be provided for the second loading step.
• the top surface 23 of jig 22' may be provided with longitudinal slits 23' adapted to receive a linear array of curved needles mounted on a plate (not shown) so as to extend through the slits 23' and the height of side walls 25 of the first jig 22' can be made adjustable by using a plurality of legs 27 pivotably mounted by pins 33 on the side walls 25 of first jig 22' .
• the legs are selectively locked in the position shown in FIG. 7 or turned 180° so as to adjust the height of side walls 25 to correspond to the height of the side walls 31 of jig 28 of FIG. 9.
• the locking of the legs in the two alternate positions can be by any conventional device such as spring loaded detents or clamps.
• the ends 20a, 20b of coils 20 of innerspring unit 30 are independently embedded within the layers of foam members 32 and 34 and adjacent coils are free of any interconnection except for the foam.
• the advantages of this independently embedded coil system include improving the comfort by removing the restrictions to individual coil action which results from conventional innerspring units where the coils are all bound to each other. Since each coil is free of any rigid connection to another coil, such as wires, the coils may compress independent of one another.
• a further advantage includes imparting greater orthopedic qualities to the mattress since, as noted above, the process allows for the placement of different gauge coils at different positions and in different patterns, allowing for a mattress to be made having a different distribution of firmness and softness. The labor, material and expense of joining coils into units before the foaming step is also avoided by the construction 95/21048
• a comfortable foamed innerspring unit 30 is prepared using a minimal amount of foam materials, labor and expense.
• the mattress produced in accordance with the process of this invention was provided with a quilted cover.
• the top and bottom panels of the cover were glued to foam members only around the perimeter thereof and the border material was sewn to the top and bottom panels using common edge tapes .
• the foamed innerspring covered with the quilted cover was then exposed to a "torture" device, a hexagonal roller that weighed 250 pounds, which was rolled in the head to foot direction over the center 36 inches of the mattress. The roller ran for seven days, 24 hours per day, for a total of 100,800 passes for the duration of the test.
• the present invention provides an efficient process for customizing a mattress to have varying degrees of firmness and softness.
• one way in which the process of this invention allows for the .formation of a mattress having varying degrees of firmness is by designing desired coil patterns and mounting the desired gauge coils on the horizontal surface of the first jig by magnet or mechanical means so that the desired gauge coils correspond with selected regions of the tray and varying degrees of firmness and softness can be provided to the head, mid-section or foot region of the mattress.
• _JI alternate embodiment of this invention which also provides for the manufacture :: a mattress having regions of varying degrees of firmness, employs the process of this invention to make foamed innerspring unit sections which together define a mattress.
• Two to six sections, or more, can be provided, preferably three in the longitudinal direction of the mattress, and if the mattress is for a double, king or queen size, two side-by- side sets of three se tions can be provided.
• Each section may have the same or different firmness from the other parts.
• the -7.esent invention provides an efficient, economical process of making a mattress having three or six innerspring components, wherein the components have at least two different firmnesses. While trays and jigs dimensioned to produce sections can be provided, one third of a twin size mattress or one sixth the size of a double (full), queen or king size mattress, such an arrangement would not be as efficient in making several sections simultaneously using regularly sized trays and jigs and existing production lines.
• the first jig 22 can be provided with a pattern on the inner surface of horizontal wall .3 corresponding to the sections created by the partitions in tray 10 so that coils of a selected gauge, which consequently provide varying degrees of firmness, are loaded into each area of the jig 22 corresponding to the three sections of the tray, which were created by placing two partitions into the tray.
• the coils 20 should be spaced on the inner surface of horizontal wall of t? ' jigs to allow for apprcrriate placement in the corresponding sections of the tray, so that sufficient space exists between coils at the partitions .
• the trays with partitions can be sprayed with the foamable reaction mixture using the array of nozzles used for full mattresses and the process of the 5/21048
• a tray 10 may be provided with two partitions extending widthwise which would consequently divide the mattress into three equal sections, a head section, middle section and foot section.
• the first jig 22 can be loaded with coils 20 corresponding to the three sections of the tray created by the two partitions so that heavy gauge coils are placed in the jig to correspond to the middle section of the tray and thinner lower gauge coils are placed in the jig to correspond to the sections of the tray flanking the middle portion, the head and foot sections of the tray, respectively.
• a mattress having three separate foamed innerspring components is produced wherein two of the components are softer than the one component loaded with thicker coils .
• the tray is provided with three partitions, two distributed widthwise in the tray and one partition extending lengthwise through the center of the tray.
• FIGS. 10, 11 and 12 show a tray having six sections, which is used in conjunction with creating six foamed innerspring unit sections, and the finished mattress made in this fashion, respectively.
• a tray 10' having partitions 36 dividing the tray into a total of 6 sections is shown in the perspective view in FIG. 10. As shown, the tray 10' has the preferred flat bottom 12'. Coils of varying gauges can be loaded into each of the six sections of tray 10'.
• FIGS. 11 and 12 show a mattress generally indicated as 38.
• the mattress is composed of six separate mattress sections, such as six separate foamed innerspring unit sections 41 made in accordance with this invention.
• the mattress is formed by placing the individual sections into compartments formed in a cover 40.
• the cover 40 for receiving the separate foamed innerspring unit sections 41 is provided with top and bottom cover layers 42, preferably quilted and glued at their periphery to innerspring components 41.
• a border 44 is joined to the top and bottom cover layers at their periphery using conventional edge defining mattress tape 45.
• Internal partitions 43 extend between top and bottom cover layers 42, secured to the bottom cover layer, by way of example, by glue 46 and to the cop cover layer, by of way of example, by stitching 47.
• a zipper 48 extends along the length of each of two sides of border 44.
• the foamed innerspring components are loaded inio each side of the cover 40 by unzippering one of the zippers 48 and placing each component 41 into an appropriate section.
• the step of gluing the top and bottom covers can be performed at this time.
• a mattress having six foamed innerspring unit sections is produced, wherein the coil patter- r of the sections in the head regions may be different form the cc pattern of the component in the middle regions and the firmness c .. the coils in the head region may be different from the firmness of the coils in the foot region.
• coils 20 in one innerspring unit section of the mattress of FIG. 11 are shown in a staggered rather than an aligned pattern.
• the coils 20' in the central section 41 are of a heavier gauge than the coils 20" of the head section 41, creating a greater degree of firmness in the center.
• the left side of the mattress can be formed of sort, firm and medium firmness sections respectively as viewed from the head, while the ri .nt side of the mattress can be formed from medium, extra firm and firm sections as viewed from the head.
• the result is a mattress which can accommodate a 250 lb and a 120 lb person sleeping side-by-side with full comfort and minimum mattress di" -rtion. While degree of firmness in the embodiment of FIG. 12 is -.termined by coil gauge, it can also be determined by foam selection. 5/21048
• the mattress cover shown generally as 52 of mattress 50 is provided with a pair of zippers 54 and 56 each extending along the length of one-half of the border 52, 58, to permit greater access to the interior of the cover.
• the internal partitions 60 are also divided in half, one half secured to the top cover layer and the other to the bottom cover layer.
• the innerspring unit sections are loaded by unzippering one side, laying in the sections, gluing and pulling the cover tight over the sections so that the partitions fall into the appropriate gap between sections .
• FIG. 16 shows a further embodiment for enclosing the separate foamed innerspring unit sections within a cover means.
• this embodiment of the present invention includes a layer of foam material wrapped about the periphery of each foamed innerspring component 41' .
• a layer of heavy cloth can also be used for this purpose.
• the peripheral wrapping is glued to the sides of foam sections 32 and 34.
• the wrapped components are inserted into a cover 62 formed without partitions.
• the cover is preferably glued to the sections at its periphery.
• This construction permits the use of a cover without separate partitions for receiving the individual foamed innerspring components.
• the components wrapped in this manner would remain secure within the cover means due to the friction between the peripheral layers wrapped about the adjacently positioned innerspring components.
• the peripheral wrapping prevents one section from being displaced vertically relative to another so that the edge of a foam member of one section enters the gap between the foam members of an adjacent section.
• FIG. 16 also demonstrates still another alternate embodiment of the invention, where an open lightweight mesh 64 is laid on the free end of the coils when the jig is in the position of FIG. 6 and secured by string or other means to a number of coils sufficient to prevent the mesh from sagging when the jig is turned over to the position of FIGS. 7 and 9.
• the mesh can be either a woven mesh or a mesh that has been extruded and stretched in a 5/21048
• the mesh is formed of nylon or polypropylene.
• the mesh serves as an insulator. In effect, the mesh provides additional strength to the foam members 32, 34 but does not serve to hold the coils in their respective positions. That function is performed by the foam.
• FIGS. 14 and 15 an alternate embodiment of the tray 10" is depicted.
• the bottom 12" of the tray 10" is not flat, but rather, is formed with a series of elongated notches or ridges 15 projecting into the interior of the tray.
• the ridges are positioned to receive the free ends 20b of the coils 20 held by magnetic force within jig 22. With this arrangement, the height of the side walls 25 of jig 22 becomes less critical.
• the construction of the innerspring unit in accordance with the invention offers substantial advantages over the prior art innerspring unit constructions, both in reduced expense and material of production and in substantial functional advantages.
• the functional advantages is not only the provision of a mattress wherein the individual coils can function more independently than in a conventional mattress where the coils are tied together by wires or the like, but also permits production of a sectioned mattress.
• the sectioned mattress offers flexibility in tailoring the design of a mattress to the consumer.
• a further possibility enabled by the sectioned construction in accordance with the invention is the possibility of selling mattresses by mail or parcel post. It is difficult to ship a full mattress by these means . It would be more practical to ship the mattress sections and a cover to the consumer with instructions as to how to assemble the mattress sections.
• the construction in accordance with the invention is particularly suited to produce effective mattress sections at reasonable cost.

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• 1995
  • 1995-02-03 WO PCT/US1995/001442 patent/WO1995021048A1/en active IP Right Grant
  • 1995-02-03 ES ES95910917T patent/ES2197195T3/es not_active Expired - Lifetime
  • 1995-02-03 AT AT95910917T patent/ATE238895T1/de not_active IP Right Cessation
  • 1995-02-03 DE DE69530575T patent/DE69530575T2/de not_active Expired - Fee Related
  • 1995-02-03 EP EP95910917A patent/EP0742751B1/de not_active Expired - Lifetime
  • 1995-02-03 AU AU18705/95A patent/AU1870595A/en not_active Abandoned

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