NL2028677B1 - Spring mattress and method of manufacturing a spring mattress - Google Patents

Abstract

The invention relates to a spring mattress, preferably a pocket spring mattress, comprising at least one core and at least one upper and at least one lower layer arranged respectively over and under the core, the core comprising a plurality of springs, preferably pocket springs. The at least one core comprises at least one first section, in which springs are arranged, and a second section, in which a foam material extends substantially from a bottom to a top of the core. The invention also relates to a method of manufacturing such a mattress.

Description

SPRING MATTRESS AND METHOD OF MANUFACTURING A SPRING MATTRESS The invention relates to a spring mattress. such as a pocket spring mattress, comprising at least one core and at least one upper and at least one lower layer arranged respectively over and under the core, the core comprising a plurality of springs, preferably pocket springs. Spring mattresses as such are known, and have found application due to their ability to provide a relatively large amount of ventilation as compared to other types of mattresses, for instance those comprising foam cores. In general, a pocket spring mattress consists of a collection of springs that are individually encased by e.g. cotton sacks. The sacks keep the springs under tension at all times. A casing is built around several springs put together, in order to keep the springs in place and to provide a surfacy to lie on. It has been known to use springs of varying stiffnesses in order to provide stiffness in one part of the mattress, and to provide flexibility in another. In practice, mattresses employing this technique are referred to as zoned mattresses. Although the zoning technique has to some extend allowed increasing sleeping comfort, a challenge remains to provide an even more comfortable mattress. It is therefore an object of the invention to provide a mattress that suits the shape of a person relatively well. The object is achieved by a mattress according to the preamble, in which the at least one core comprises at least one first section, in which springs are arranged, and a second section, in which a foam material extends substantially from a bottom to a top of the core.

By building up different sections of the core with different techniques, a relatively large difference in behaviour of the core can be made between the sections. In particular, it is advantageous to provide a spring section, which is relatively stiff, and a foam section, which may allow a relatively large deformation. As such, parts of the body that are wider than others, such as the shoulders, may be allowed to sink into the mattress relatively far. As a result, the spine of a person ving on the mattress may remain relatively straight. In general, a mattress comprises one or more layers on top of the core in order to provide a surface for lying on. The top and bottom of the core may be defined as the plane in which the tops of the springs in the first section lie.

In particular, the second section comprises a shoulder section of the mattress, or the second section is a shoulder section of the mattress. As a result, the mattress may allow the shoulder of a person on the mattress to sink into the mattress relatively deep, as the foam material in the second section aligns with the shoulder of the person. Other parts of the person’s body, which are generally less wide, may still be supported by at least the first section, 1.e. by springs. In particular, the first section comprises a lumbal and/or lower body section.

The lumbal and lower body section may profit from support by springs, particularly due to this support being relatively firm. In particular, weight of a person may be concentrated near the waist and/or hips, which may therefore benefit from spring support. Moreover, the legs and feet may benefit from spring support, as they are relatively narrow and need not sink into the mattress as far ase.g. the shoulder in order to provide a comfortable position. It is noted the second section may be completely filled by the foam material, wherein preferably no springs are arranged in the second section.

Providing no springs at all and/or by providing only the foam material in the second section, maximal flexibility can be achieved in the second section. In an embodiment of the spring mattress, the foam material has a substantially cuboid shape, wherein preferably its width exceeds its length. both as defined in a width and length direction of the mattress respectively. Having a foam material in a cuboid shape allows working with blocks of foam material, which may facilitate production. Moreover, existing production technologies for foam material may be employed, as normal foam cores can relatively easily be shaped into cuboids of the desired dimensions. Moreover, foam material of a cuboid shape may provide a planar side surface which may interface closely with springs in the first section near the second section. In another embodiment of the spring mattress, the at least one upper and/or the at least one lower layer comprise a through hole exposing at least a part of the second section.

Exposing the second section allows e.g. a shoulder of a person to sink into the mattress at the section more easily. The applicant has found that even if a relatively flexible core is provided, e.g.

of a possibly soft foam material, layers extending over the top of the core at the section may limit deformation of the second section by tensioning itself over the second section. Exposing the second section through at least one layer at least partially prevents this problem.

In particular, a through hole may be provided in a layer providing tensile strength, such as a pressure distributor. Any other layers, such as comfort layers and/or encasing, may be continuous. A flush surface may accordingly be provided by the comfort layer(s) and/or encasing, whereas the through hole in the pressure distributor allows sinking into the foam material relatively easily.

In case the comfort layer is also provided with a through hole, it may be advantageous if the foam material extends through the through hole in order to form a surface substantially flush with the comfort layer.

The second section may also be exposed at the bottom, so that the mattress can be used on both sides.

It is advantageous if the at least one upper and/or lower layer extends over the second section for a part thereof. In accordance therewith, the at least one upper and/or lower layer may be used to fix the first and second sections of the core material to each other and to other parts of the mattress.

In another embodiment, the through hole is substantially oval-shaped.

The oval shape allows the at least one upper and/or lower layer to extend over the second section near the sides of the core, thereby allowing fixation of the second section of the core to the layers, whilst exposing a relatively large part of the second section in the centre of the second section. Further, the oval shape provides a smooth profile of the at least one upper and/or lower laver, which are therefore less likely to cause discomfort to a user and/or may be less likely to tear.

In vet another embodiment of the spring mattress, the foam material is attached to the at least one upper and/or the at least one lower layer.

By attaching the foam material to the upper and/or lower layer(s), the second section can be kept together with the first section, thereby making a mattress that is relatively easy to move. Moreover, such a configuration prevents the sections of the core from moving apart.

The springs may in turn also be affixed to the at least one upper and/or lower layer.

For fixing parts of the mattress together, glue or other adhesive may be used. In vet another embodiment of the spring mattress, the core comprises a third section. in which springs are arranged, the first and third sections being arranged on opposing sides of the second section.

Including another spring section in the core allows creating a second relatively stiff section for e.g. a head of a user. Placing the second section in between spring sections allows localizing the relatively flexible second section.

The third section may be a head section, or may comprise a head section. In yet another embodiment of the spring mattress, the second section extends over substantially the entire width of the core.

Extending the second section over the entire width allows a relatively easy method of producing the spring mattress. In particular, rows of springs extending in the width direction of the mattress may be removed and may be replaced by the foam material to form the second section. The removed rows can then be reused to form ¢.g. a part of another mattress’ first section.

It is possible to provide a double mattress with either one or two cores. In any case, the second section may extend over the entire width of the respective core. It is of course also possible to provide only one of two cores with a second section. The other core may be configured in an alternative, for mstance traditional, way.

In yet another embodiment of the spring mattress, the first section comprises a first type of springs and a second type of springs, the second type of spring having a lower spring constant and/or a smaller size than the springs of the first type, wherein the springs of the second type are arranged between the second section and the springs of the first type.

The springs of the second type, by virtue of their smaller spring constant or smaller size, may provide a relatively gradual transition between the first and second sections. The gradual transition may result in a more comfortable mattress. In case shorter springs are chosen for the second type. additional foam material may be provided under and/or above the shorter springs to provide a flush surface with the rest of the first section.

It is in principle possible to also provide the third section with springs of a or the second type. however such is not strictly necessary. It is therefore more elegant to provide the third section with identical springs, e.g. of the first type. 5 In particular, the springs of the second type may have a thread diameter that is smaller than a thread diameter of the springs of the first type. By choosing springs with a smaller thread diameter, a smaller spring constant may be achieved. Other methods to reduce the spring constant may be emploved additionally or as an alternative.

In yet another embodiment of the mattress, the foam material is a latex foam. Latex foam may be particularly suitable in the mattress as described above, as it allows a relatively large deformation without providing a large restoring force. Moreover, as compared to other foams latex may be relatively durable, and may have as an additional or alternative advantage that it may be made of natural materials. In yet another embodiment of the spring mattress, the at least one upper and/or the at least one lower layer comprise a pressure distributor and a comfort layer.

The pressure distributor may be used to distribute pressure across several springs. Usually, the pressure distributor is a relatively thin sheet material, whish resists tensile force, made for instance using fibres, such as natural fibres. The pressure distributor may be a woven or non-woven textile.

The comfort layer, sometimes also referred to as cover, in generally provides a comfortable surface to lie on. The comfort layer may be comprised of a foam layer. The comfort layer may be substantially thicker than the pressure distributor, but less thick than the core. It is in principle possible to provide the above-mentioned through hole through some but not all layers over or under the core. As a particular example, the through hole may be provided in the pressure distributor, but not in the comfort layer. Nevertheless, it is advantageous to provide the through hole in at least the pressure distributor and the comfort layer, and possibly in all other layers should they be present, so as to benefit maximally from the flexibility of the foam material in the second section of the core.

The spring mattress may further comprise a casing substantially encasing the core, the casing optionally forming comfort layers. The casing may be used in part to keep components of the mattress together. The casing may comprise a foam material, and thereby add to the comfort of the mattress. In particular, the casing may form the comfort layers. It is however also possible to provide separate comfort layers and a casing. The invention also relates toa method of manufacturing a spring mattress, the method comprising the steps of: a) providing a first core section comprising springs; b) providing a second core section comprising a foam material; ¢) placing the first and second core sections adjacent each other; and d) providing at least one upper and at least one lower layer over the first section and over atleast a part of the second core section. The resulting mattress may have a relatively stiff first section and a relatively flexible second section, which allows deformation. As described above in relation to the mattress itself, this may offer the advantage of suiting the shape of a person by allowing ¢.g. a shoulder to sink into the mattress. The method may be used to manufacture a mattress as described above. In particular the at least one upper and the at least one lower layer may extend over only a part of the second core section. In an embodiment of the method, the second core section consists of a foam material, such as a latex foam. In accordance, the second core section may contain only said foam, and in particular no springs.

The second core section may extend from a bottom to a top of the core. It may therefore make up the entire thickness of the core across its respective area. The invention will be further elucidated with reference to the attached drawings, in which: Figure 1 shows schematically a cross section of a pocket spring mattress known from the prior art;

Figures 2A and 2B show respectively schematically a longitudinal cross section and a planar cross section of a spring mattress. Throughout the figures, like elements are referred to using like reference numerals. Like elements of different mattresses are referred to using reference numerals increased by one hundred (100). Figure 1 shows a pocket spring mattress 1 with a person 2 lying on top. The mattress 1 comprises a core 3 consisting of a series of springs 4, not all of which have been provided with reference numerals for the sake of clarity. The springs 4 are arranged in pockets 5, not all of which have been provided with reference numerals for the sake of clarity. The pockets 5 containing the springs 4 are kept together by pressure distributors 6, 8 on the top and bottom of the core 3. Further, comfort layers 7, 9 are provided over and under the pressure distributors 6, 8. The comfort layers 7, 9 combined with side wall pieces 10 form a casing which complete enclose the core 3 and the pressure distributors 6, 8.

Figures 2A and 2B show another mattress 101, which bear some similarity to the mattress 1 of figure 1. Figure 2B shows a planar cross section, in which the pocketed springs 104 of the core 103 are shown as well, in order to more easily describe the invention. The mattress 101 comprises like before a core 103 with springs 104 in pockets 105. The core 103 comprises, in a shoulder section 112 thereof (indicated in figure 2A by dashed lines). a block of foam material 111 which extends from the bottom to the top of the core 103. Thus, the foam material 111 extends over the entire height of the core 103, and no springs are arranged in the shoulder section 112. In this example the foam material is a latex foam material 111.

The foam material 111 has a cuboid shape, which in this example is relatively wide as compared to its length, the width and length being defined in the width direction W and length direction L of the mattress 101. The width of the block of foam material 111 corresponds substantially to the width of the core 103. Although a single mattress 101 is shown in this figure, the foam material block 111 can be applied to double mattresses as well, for instance by providing a wider block of foam maternal 111, or by providing two separate blocks for instance in separate cores.

A lumbal and/or lower body section 113 and a head section 114 can be identified on either side of the shoulder section 112. The core 103 in the lumbal and/or lower body section 113 and the head section 114 is provided with springs 104 arranged in pockets 105. The different sections 112, 113, 114 of the core are held together by amongst others pressure distributors 106, 108. Comfort layers 107, 108 are arranged over and under the pressure distributors 106, 108. Together with side wall parts 110 the comfort layers 107, 108 form an encasing for the core 103 and the pressure distributors 106, 108. Although in this example the comfort lavers 107, 109 are therefore part of the encasing. it is also possible to provide a separate encasing around the comfort layers 107, 109. In the example shown, the pressure distributors 106, 108 are fixed to the pockets 105 containing the springs 104 and to the foam material 111, and to the comfort layers 107, 109. In order to expose the foam material 111 on the top and bottom of the mattress 101 an in this example oval shaped through hole 115 has been provided in the pressure distributors 106, 108 and comfort layers 107, 109.

The core 103 comprises, in its lumbal and/or lower body section 113 springs 104 of different types. The first type of spring 116, are arranged in rows 118 throughout most of the section 113. The second type of spring 117, is arranged in a row 119 closest to the foam material 111. The springs 116, 117 are collectively referred to using reference numeral 104. The second type of spring 117 has a relatively low spring constant as compared to the first type of spring 116. The second type 117 is thus more easily compressed, and acts as a transition between the foam material 111 and the springs of the first type 116, which has been schematically shown by the second type of spring 117 being smaller and having a larger pitch. Alternative or additional methods to reduce the spring constant of the second type of springs 117 exist. In particular, it is envisioned springs with a lower thread diameter may be used.

Although the invention has been described above with reference to specific examples and embodiments, the scope of this application is not limited thereto. In fact, the scope is also defined by the claims, which now follow.

Claims (19)

Conclusions 1. Spring mattress, preferably a pocket spring mattress, comprising at least one core and at least one upper and at least one lower layer respectively arranged above and below the core, wherein the core comprises a number of springs, preferably pocket springs, with the characterized in that the at least one core comprises at least one first section. in which springs are provided, and a second section in which a foam material extends substantially from a bottom to a top of the core. 2. A spring mattress according to the preceding claim, wherein the second section comprises a shoulder section of the mattress. A spring mattress according to the preceding claim, wherein the first section comprises a lumbar and/or lower body section. 4. A spring mattress according to any one of the preceding claims, wherein the second section is completely filled with the foam material, wherein preferably no springs are arranged in the second section. A spring mattress according to any one of the preceding claims, wherein the foam material has a substantially beam-shaped shape, preferably with its width greater than its length, both as defined respectively in a width and length direction of the mattress. A spring mattress according to any one of the preceding claims, wherein the at least one upper and/or the at least one lower layer comprises a through hole exposing at least a part of the second section. A spring mattress according to the preceding claim, wherein the through-hole is substantially oval. A spring mattress according to any one of the preceding claims, wherein the foam material is attached to the at least one upper and/or the at least one lower layer. A spring mattress according to any one of the preceding claims, wherein the core comprises a third section in which springs are arranged, the first and third sections being arranged on opposite sides of the second section. A spring mattress according to the preceding claims, wherein the third section is a main section. A spring mattress according to any one of the preceding claims, wherein the second section extends over m substantially the entire width of the core. A spring mattress according to any one of the preceding claims, wherein the first section comprises a first type of spring and a second type of spring, the springs of the second type having a lower spring constant and/or smaller dimensions than the springs of the first type. wherein the springs of the second type are arranged between the second section and the springs of the first type. A spring mattress according to the preceding claim, wherein the springs of the second type have a wire diameter smaller than a wire diameter of the springs of the first type. A spring mattress according to any one of the preceding claims, wherein the foam material is a latex foam. A spring mattress according to any one of the preceding claims, wherein the at least one upper and/or the at least one lower layer comprises a pressure distributor and a comfort layer. 16. A spring mattress according to any one of the preceding claims, comprising a sleeve which substantially surrounds the core, the sleeve optionally forming comfort layers. A method of manufacturing a spring mattress, preferably according to any one of the preceding claims, wherein the method comprises the steps of: a) providing a first core section comprising springs; b) providing a second core section comprising a foam material; c) juxtaposing the first and second core sections; and d) providing at least one top and at least one bottom layer over the first section and over at least a portion of the second core sections. A method according to the preceding claim, wherein the second core section consists of a foam material. A method according to any one of the preceding claims, wherein the second core section extends substantially from a bottom to a top of the core.