A chain of pocket springs, a suspension system for bedding mattresses comprising a plurality of such chains and mattresses comprising such a suspension system.

Abstract

The invention relates primarily to a string of helical springs (2) housed in individual pockets formed between two overlapping panels of flexible fabric and delimited by connecting zones joining the two panels. These pockets comprise transverse connecting zones extending parallel to the longitudinal axes of the helical springs (2) and a longitudinal connecting zone opposite and substantially parallel to the longitudinal fold of the two panels. Each pocket contains a helical spring (2) comprising two spring sections, respectively for comfort (12) and support (13), connected in series to each other by an eccentric intermediate section (14). The ratio between the length of the support section (13) and the length of the comfort section (12) is between 1.5 and 2.5. Figure to be published with the abstract: Fig. 1

Description

Title of the invention: A chain of pocket springs, a suspension system for bedding mattresses comprising a plurality of such chains and mattresses comprising such a suspension system. technical field

[0001] The invention relates to a string of helical springs housed in individual retaining pockets and intended for the manufacture of pocket spring suspensions for bedding mattresses. Prior art and disadvantages of prior art

[0002] A known pocket spring suspension for bedding mattresses consists of a plurality of parallel chains of springs housed in individual pockets. Each chain of pocket springs is attached to each adjacent chain by adhesive strips spread over the mutually arched, tangential outer surfaces of the pockets. The adhesive strips used to attach one pocket of the chain to an adjacent pocket of the adjacent chain can be formed by two parallel strips of adhesive located a certain distance apart and spread over the arched outer face of the pocket perpendicular to the longitudinal direction of the spring housed in that pocket.

[0003] The individual pockets of a rosary, in each of which a spring is housed, are formed between two folded panels of an elongated, heat-sealable, flexible fabric strip and are delimited by heat-sealing lines transverse to the strip, located between adjacent springs and parallel to the longitudinal direction of each spring, and a longitudinal heat-sealing line opposite and substantially parallel to the longitudinal fold area of ​​the two panels of the strip.

[0004] Thus, the successive transverse heat-welding lines extend straight across practically the entire width of the rosary band and are located at a determined distance from each other so as to define the width of each spring housing pocket and the longitudinal heat-welding line defines the height of each pocket.

[0005] However, this known suspension has the disadvantage of offering only one type of comfort, typically firm, soft or intermediate.

[0006] To overcome this drawback, there is publication FR 2 861 270 in the name of the applicant which describes a pocket spring suspension for bedding mattresses comprising a plurality of chains of helical pocket springs assembled together as described above. According to this known suspension, each Each pocket of a rosary contains two barrel-shaped helical springs connected in series by at least one smaller-diameter central coil. This spring configuration ensures both firm support for the mattress made of such rosaries of springs and a comfortable feel for the user.

[0007] However, the balance between sleeping firmness and comfort felt by the user lying on a mattress made up of a set of beads as described in the applicant's publication is not optimized. Objective of the invention

[0008] The present invention aims to overcome the above-mentioned drawbacks of known suspensions. Description of the invention

[0009] To this end, the invention relates to a string of helical springs housed parallel to each other in individual retaining pockets formed between two folded panels of a flexible, elongated fabric strip, and delimited by connecting zones joining the two panels together and comprising transverse connecting zones extending parallel to the longitudinal axes of the helical springs and a longitudinal connecting zone opposite and substantially parallel to the longitudinal fold zone of the two panels, according to which each pocket contains a helical spring comprising two spring parts respectively for comfort and support, which spring parts are connected in series to each other by at least one coil of smaller diameter forming an intermediate part which is eccentric between said two spring parts, and, for each spring of the string,The ratio between the length of the support section and the length of the comfort section is between 1.5 and 2.5.

[0010] The rosary of the invention may also include the following optional features considered individually or according to all possible technical combinations: - For each spring in the rosary, the ratio between the length of the support part and the length of the comfort part is 2. - For each spring in the rosary, the ratio between the pitch of the support part and the pitch of the comfort part is between 1 and 2. - For each spring in the rosary, the ratio between the pitch of the support part and the pitch of the comfort part is 1.5. - For each spring, the ratio between the total length of the uncompressed spring and the total length of said compressed spring is between 1.1 and 1.2. - For each spring, the total length of the compressed spring is between 20 and 23 centimeters. - For each spring, the ratio between the length of the comfort part and the length of the intermediate part is between 1.5 and 2.5. - Each transverse connection zone includes, between two adjacent pockets, a first width at the level of the comfort part of each spring, a second width at the level of the support part of each spring, and a third width at the level of the intermediate part of each spring, which third width is greater than each of the first and second widths. - Each transverse connection zone includes, between two adjacent pockets and at the level of each intermediate part of smaller diameter, a space delimited by two connection lines spaced apart to define a closed and elongated contour parallel to the longitudinal axes of the springs. - The space delimited by the two connecting lines is more elastic than the rest of the flexible fabric strip. - The space delimited by the two connecting lines is a recess in the shape of an elongated window which is formed by removing material from the fabric between the two connecting lines.

[0011] The invention also relates to a pocket spring suspension for bedding mattresses, comprising several parallel strings of pocket springs connected to each other, each string being as described above.

[0012] The invention also relates to a bedding mattress intended to be placed on a bed base and comprising an internal pocket spring suspension as described above. Presentation of the figures

[0013] Other features and advantages of the invention will become clear from the description given below, by way of example and not limitation, with reference to the accompanying figures, among which:

[0014] [Fig. 1] Fig. 1 represents a perspective view of a rosary spring according to the invention;

[0015] [Fig.2] Fig.2 represents an elevational view of a chain of springs according to the [Fig.1] bagged. Detailed description of the invention

[0016] It is first specified that in the figures, the same references designate the same elements regardless of the figure in which they appear and regardless of the form of representation of these elements. Similarly, if elements are not specifically referenced in one of the figures, their references can easily be found by referring to another figure.

[0017] It is also specified that the figures essentially represent one embodiment of the object of the invention but that there may be other embodiments which meet the definition of the invention.

[0018] Referring first to [Fig.2], the string 3 with pocket springs 2 is manufactured by the known process of first inserting the axially compressed springs 2 between two superimposed panels of an elongated heat-sealable fabric strip 8 in positions or locations spaced longitudinally on the strip and then thermally welding the two panels to each other along heat-welding zones 9 transverse to the strip 8 arranged between the successive compressed springs 2, each heat-welding zone 9 between two springs 2 being formed of several lines, and a heat-welding zone 10 formed of a line extending substantially parallel to the longitudinal fold zone 11 of the panels, so as to form a retaining pocket 6 for each spring.After these pockets have been formed, the springs 2 inside the pockets are rotated so that they relax in such a way that their longitudinal axes are transverse to the longitudinal fold area 11 and, consequently, parallel to the transverse heat-sealing lines 9. The non-woven material of the strip 8 is flexible and the heat-sealing lines 9, 10 are obtained by ultrasound.

[0019] In particular, and for each spring 2, the ratio between the total length of said uncompressed spring 2 and the total length of said compressed spring 2 is between 1.1 and 1.2. This ensures an optimal compromise between the stability of the chain of springs 3 and the latitude of deformation of the springs 2 in said chain 3. Furthermore, in order to maintain this optimal compromise, the total length of the compressed spring is between 20 and 23 centimeters.

[0020] Each chain 3 thus makes it possible to effectively hold in each pocket 6 a spring 2 without risk of being placed sideways when a load is applied to it vertically and also makes it possible to increase the sleeping independence of a mattress equipped with such chains.

[0021] The adjacent strings 3 of pocket springs 2 are connected to each other by discontinuous or continuous lines of adhesive (not shown) following the longitudinal direction of the springs 2 to form a pocket spring suspension of a bedding mattress.

[0022] According to the embodiment of the invention shown in Figures 1 and 2, each pocket 6 of a chain 3 contains a helical compression spring 2 comprising two spring sections 12, 13 connected in series to each other by one or more smaller diameter central coils 5 forming an intermediate section 14, which spring sections 12, 13 are respectively constituted by an upper barrel-shaped spring section, referred to as the comfort section 12, and a lower spring section also in a barrel called a holding 13 arranged on either side of the intermediate part 14.

[0023] The comfort spring sections 12 are referred to as upper because they must be located in the upper portion of a mattress, with the outermost coils of the smallest diameter 22 of these comfort sections 12 positioned under the sleeping area of ​​the mattress. The support spring sections 13 are referred to as lower because they must be located in the lower portion of the mattress, with their outermost coils 23 forming the bases of these support sections 13 resting on the fold area 11 and intended to rest on the upper surface of a bed base S.

[0024] The 3 sets of springs 2 in pockets having the configuration shown in [Fig.2] are intended for the manufacture of relatively thick mattresses which are not intended to be turned over by their user, that is to say they have only one sleeping surface, the one under which are the comfort parts 12 of the springs 2.

[0025] According to the invention and with reference in particular to [Fig. 1], for each spring 2 of the chain 3, the ratio between the length of the support part 13 and the length of the comfort part 12 is between 1.5 and 2.5, and is preferably 2. Thus, a mattress consisting of a suspension formed of a plurality of chains 3 with the springs 2 of the invention combines firm support properties thanks to the support parts 13 of the springs 2, with softness properties on the upper part of the mattress conferred by the comfort parts 12 of the springs 2, giving a feeling of comfort to the user using the mattress.

[0026] Furthermore, the comfort part 12 typically includes a coil arranged between its end coils 22 and the intermediate part 14, while the support part 13 includes two coils arranged between its end coils 23 and the intermediate part 14.

[0027] Furthermore, the ratio between the coil pitch 20 of the support part 13 and the coil pitch 21 of the comfort part 12 is between 1 and 2, and is preferably on the order of 1.5. This configuration optimizes the optimal balance between perceived comfort - thanks to the comfort parts 12 of the springs 2 - and sleeping firmness - thanks to the support parts 13 of the springs 2 - the stiffness of the comfort part 12 being less than that of the support part 13.

[0028] Finally, for each spring 2, the ratio between the length of the comfort part 12 and the length of the intermediate part 14 is between 1.5 and 2.5. This configuration avoids a collapse effect of the comfort part 12 of the spring 2 when it is compressed under the weight of the user, if it were made up only of coils of small diameter, equal to the diameter of the coils of the intermediate part 14.

[0029] Figure 2 shows that each transverse heat-sealing line 9 is divided towards the longitudinal line 10 into two oblique heat-sealing lines 15 defining a open V shape in the opposite direction to the fold area 11 or towards the line 10 so as to decrease the width of each retaining pocket 6 of the comfort part 12 of the spring considered 2 in the area of ​​this pocket 6 where is housed the upper end part of the smallest diameter of the coils 22 of the comfort part 12 of the spring.

[0030] The two oblique heat-welding lines 15 located on either side of a comfort part 12 have an inclination and a height from their straight transverse heat-welding line 9 such that they configure a part of the upper pockets into an approximately frustoconical shape allowing to enclose practically without play the approximately frustoconical conjugate upper end part of the smallest diameter of the comfort part 12 of the spring.

[0031] Fig. 2 further shows that the chain of springs in pockets 3 is provided with cutouts 16 made by removing material from the strip 8 between the branches of the different pairs of oblique lines 15 to configure each cutout 16 substantially in the shape of a V embedded in the conjugate V shape defined by two oblique heat-welding lines 15 associated with a transverse heat-welding line 9.

[0032] Two successive cuts 16 in the band 8 define between them an approximately frustoconical pocket portion allowing axial compression or indentation of at least the corresponding comfort portion 12 without causing indentation of the neighboring comfort portions 12 due to the absence of fabric between two adjacent frustoconical pocket portions. Thus, the cuts 16 provide the springs 2 of the chain 3 with greater independence than those of a traditional chain.

[0033] In addition, each lower transverse heat-sealing line 9 is divided opposite the longitudinal connecting line 10, as opposed to the upper transverse heat-sealing line 9 into two upper oblique connecting lines 15, into two further oblique connecting lines 15 defining a V-shape open towards the fold area 11 of the two sides of the strip 8 and a lower V-shaped cut 16 is made by removing material from the part of the fabric located between the two branches of the V-shape of the two lower oblique lines 15 to give each end portion of a pocket 6 a substantially frustoconical shape to house an end portion of the smaller diameter coils of the retaining part 13 of the spring considered 2.

[0034] Fig. 2 shows that each transverse connecting zone 9 comprises, between two adjacent pockets 6, a first width L1 at the level of the comfort part 12 of each spring 2, a second width L2 at the level of the support part 13 of each spring 2, and a third width L3 at the level of the intermediate part 14 of each spring 2, which third width L3 is greater than each of the first and second widths L1, L2.

[0035] Each transverse connecting zone 9 comprises, between two adjacent pockets 6 and at the level of each intermediate part of smaller diameter 14, a space delimited by two connecting lines 17 spaced apart to define a closed and elongated contour parallel to the longitudinal axes of the springs 2. Preferably, this contour is oval in shape.

[0036] The two connecting lines 17 thus delimit an elongated oval space, which is made of a more elastic material than the rest of the fabric strip 8. According to a preferred embodiment, the space delimited by the two connecting lines is a recess 18 formed by removing material from the fabric between the two substantially arched connecting lines 17 so that this recess has approximately an elongated oval shape parallel to the transverse line 9.

[0037] The presence of the arched connecting lines 17 and the recesses 18 at the intermediate part 14 of the springs 2 between the adjacent pockets 6 allows, on the one hand, for the comfort parts 12 and support parts 13 of the springs 2 to be effectively maintained in their respective pockets so that they can work vertically in compression when a load is applied to them and to prevent the comfort parts 12 and support parts 13 from becoming crooked to catch on other neighboring comfort parts 12 and support parts 13 causing either a sagging of the chain 3, or noise, and on the other hand, for increasing the sleeping independence criterion of a mattress equipped with chains 3 conforming to that of [Fig.2], compared to a mattress equipped with traditional barrel-shaped pocket spring chains.

[0038] The recesses 18 between the adjacent pockets 6 of a string 3 can be made by any known means, for example by ultrasound, by a cutting and punching machine, or by die-cutting.

[0039] Finally and alternatively, the recesses 18 can simply be replaced by a crushing, by flattening or compression, of the intermediate part 14 of the spring 2.

[0040] The invention has been described with reference to rosaries whose pockets are formed from transverse and longitudinal heat-sealed lines, but it is understood that it can be applied to rosaries whose transverse and longitudinal lines are made by sewing.

Claims

Demands

1. A string (3) of helical springs (2) housed parallel to each other in individual retaining pockets (6) formed between two overlapping panels of a flexible, elongated strip of fabric (8), and delimited by connecting zones (9, 10) joining the two panels together and comprising transverse connecting zones (9) extending parallel to the longitudinal axes of the helical springs (2) and a longitudinal connecting zone (10) opposite and substantially parallel to the longitudinal fold zone (11) of the two panels, wherein each pocket (6) contains a helical spring (2) comprising two spring parts, respectively comfort (12) and support (13), which spring parts (12, 13) are connected in series to each other by at least one coil (5) of smaller diameter forming an intermediate part (14) which is eccentric between said two spring parts (12, 13),characterized in that, for each spring (2) of the chain (3), the ratio between the length of the support portion (13) and the length of the comfort portion (12) is between 1.5 and 2.5, in that, for each spring (2) of the chain, the ratio between the coil pitch (20) of the support portion (13) and the coil pitch (21) of the comfort portion (12) is 1.5, and in that, for each spring (2), the ratio between the total length of the uncompressed spring and the total length of said compressed spring is between 1.1 and 1.

2.

2. Rosary (3) according to the preceding claim, characterized in that, for each spring (2) of the rosary, the ratio between the length of the support part (13) and the length of the comfort part (12) is 2.

3. Rosary (3) according to the preceding claim, characterized in that, for each spring (2), the total length of the compressed spring (2) is between 20 and 23 centimeters.

4. A rosary (3) according to any one of the preceding claims, characterized in that, for each spring (2), the ratio between the length of the comfort part (12) and the length of the intermediate part (14) is between 1.5 and 2.

5.

5. A string (3) according to any one of the preceding claims, characterized in that each transverse connecting zone (9) includes, between two adjacent pockets (6), a first width (L1) at the level of the comfort part (12) of each spring (2), a second width (L2) at the level of the support part (13) of each spring (2), and a third width (L3) at the level of the intermediate part (14) of each spring (2), which third width (L3) is greater than each of the first and second widths (L1, L2).

6. A string (3) according to any one of the preceding claims, characterized in that each transverse connecting zone (9) comprises, between two adjacent pockets (6) and at the level of each intermediate part of smaller diameter (14), a space delimited by two connecting lines (17) spaced apart to define a closed and elongated contour parallel to the longitudinal axes of the springs (2).

7. Rosary (3) according to the preceding claim, characterized in that the space delimited by the two connecting lines (17) is more elastic than the rest of the flexible fabric strip (8).

8. Rosary (3) according to the preceding claim, characterized in that the space delimited by the two connecting lines (17) is a recess (18) in the shape of an elongated window which is formed by removing material from the fabric between the two connecting lines (17).

9. Pocket spring suspension for bedding mattresses, comprising several parallel strings (3) of pocket springs (2) linked together, characterized in that each string (3) conforms to any one of the preceding claims.

10. Bedding mattress intended to be placed on a bed base and comprising an internal pocket spring suspension (2) conforming to the preceding claim.