Abstract:
A spring core includes a plurality of helically wound springs. At least two of the springs include a bulging at least at one of two end regions of each of the at least two springs in a direction of a longitudinal axis of the at least two springs.

Description:
CROSS-REFERENCE  
       [0001]     This application claims priority to German Application 10 2005 053 123.7 filed Nov. 8, 2005, which disclosure is hereby incorporated herein by reference.  
       BACKGROUND AND SUMMARY  
       [0002]     The present disclosure relates to a spring core having a plurality of helically wound springs.  
         [0003]     The springs of such spring cores are normally made of wire and are known, for example, as Bonell springs or barrel springs.  
         [0004]     The spring cores formed thereof have a superlinear, that is, uniform spring action. The same degree of hardness exits at any point in time of the use of the spring core.  
         [0005]     For improving the cushioning comfort when a mattress containing the spring core is used, demands are made with respect to first permitting a soft sinking-in of certain body regions before a stronger support has its effect.  
         [0006]     For this purpose, it has been attempted to achieve a certain softness by applying padding. However, this application of padding to the mattress is not suitable for meeting the demands in the widest sense of the word, particularly because the elasticity of such padding is not comparable with a springiness.  
         [0007]     From German Patent Document DE 29722598U1, a spring core is known where the lying comfort is to be improved in that the springs of the individual rows have different heights. However, this results in a change of the spring characteristics, which in principle does not lead to a satisfactory result.  
         [0008]     Furthermore, the production of such a spring core requires higher expenditures and is more problematic than that of a spring core whose springs all of the same height.  
         [0009]     The present disclosure relates to a spring core such that the comfort of resting on it is improved at the lowest possible manufacturing expenditures.  
         [0010]     The present disclosure thus relates to a spring core including a plurality of helically wound springs, At least two of the plurality springs are shaped as or include a bulging at least at one of two end regions of each of the at least two springs in a direction of a longitudinal axis of the at least two springs.  
         [0011]     As a result of the construction of the individual springs, which together form the spring core, a more progressive spring action is obtained which achieves a very sensitive resilience, in which case the surface of the spring core feels extremely soft.  
         [0012]     To a desired extent, projecting body regions can at first sink deeper into the mattress, but, after a compression of the bulging, a harder spring characteristic becomes effective, which optimally supports the lying person.  
         [0013]     The progressive spring force achieves a remarkable relaxation, for example, of the spine, so that the new spring core optimally meets the demands with respect to a high springing comfort.  
         [0014]     According to an embodiment of the present disclosure, it is provided that both end regions of each spring are shaped in the manner of a bulging. In addition to an optimized lying comfort, this results in a greater load capacity of the spring core.  
         [0015]     By pitches of the wire winding which differ in regions, the spring action of the spring can be influenced. A pitch which is flat toward the ends and steep toward the center supports at first a soft and then a harder springing when the spring core is used.  
         [0016]     The springs constructed according to the present disclosure may be mutually connected by a spiral wire in the manner of a Bonell spring core. However, they may be used as pocket springs. That is, they are enveloped by a fabric pocket. A plurality of springs form a strand and these strands, arranged side-by-side, are glued to one another in the region of the jacketed springs. The gluing-together takes place, for example, by a hot-melt adhesive, which is applied at the bulges.  
         [0017]     Instead of a direct gluing-together of the strands, intermediate layers of an elastic material, such as a foamed material, may be provided. The intermediate layer is arranged between two strands and is glued together with the adjacent strands.  
         [0018]     The pockets enveloping the springs are adapted to the shape of the new spring. In a manner known, fabric strips extending over the entire length of a strand are used for forming the pockets. In the region of two successive springs, these fabric strips are connected with one another by ultrasonic sealing, corresponding to the shape of the spring, while forming the above-mentioned pockets.  
         [0019]     Between the springs, in one strand as well as between two strands, differently shaped springs, such as barrel springs, may also be arranged. In this case, the center bulging of the barrel can then be inserted into the center constriction of the new spring. If a new spring with only one bulging is used, the opposite side of the spring core can be determined by the inserted barrel springs, so that a turner mattress is obtained which has different lying characteristics.  
         [0020]     Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a lateral view of an individual spring of a spring core, according to the present disclosure.  
         [0022]      FIG. 2  is a lateral view of a partial cutout of a spring core, according to the present disclosure.  
         [0023]      FIG. 3  is a top view of the partial cutout of  FIG. 2 .  
         [0024]      FIG. 4  is a lateral view of a partial cutout of another embodiment of a spring core, according to the present disclosure.  
         [0025]      FIGS. 5 and 6  are views of a partial cutout of a spring core in a connection region of two individual springs, according to the present disclosure. 
     
    
     DETAILED DESCRIPTION  
       [0026]      FIG. 1  shows a helically wound spring  1  of a spring core, according to an embodiment of the present disclosure.  
         [0027]     Spring  1  is shaped as or includes a bulging  2 ,  3 , for example, at its two end regions  11 , while a center part situated in-between bulging  2 ,  3  is a throat  4  having a reduced diameter.  
         [0028]     Starting from a relatively smaller diameter of windings of the spring  1 , this relatively smaller diameter increases and then decreases and changes into a region of the throat  4  in order to then expand again and finally decrease. A new shape is thus obtained which is shown in  FIG. 2 . With respect to a transverse axis of the spring  1 , springs  1  have a mirror-symmetrical shape.  
         [0029]      FIG. 2  shows springs  1  which are disposed side-by-side and are enveloped by pockets  5 . These pockets  5  include a textile material and combine a row of individual springs  1  disposed side-by-side to form a strand or a row. Pockets  5  are formed in that two fabric strips covering individual springs  1  on both sides between two individual springs are mutually connected by ultrasonic sealing, such as sealing seam  7  shown in  FIG. 3 .  
         [0030]      FIG. 3  also shows an elastic intermediate layer  6 , which may include a foamed material. Intermediate layer  6  is arranged between two spring strands, which intermediate layer  6  is glued to two adjacent spring strands and thereby forms a connection element. In their entirety, the intermediate layers  6  result in a completion of the spring core.  
         [0031]     A mutual spacing of the individual spring strands changes depending on the width of the intermediate layer  6 , which results in a change of the spring characteristic of the spring core.  
         [0032]     Instead of such an intermediate layer  6 , which extends along an entire length of the spring strands, individual spacers can be used to fill spaces formed between two spring strands. The spacers are also connected with adjoining springs  1  or their pockets  5 . Such spacers may also be formed of a foamed material, but may include springs  1 , which may be barrel springs. The barrel springs rest laterally against the throats  4  of the adjoining springs  1 . In an embodiment shown in  FIG. 4 , the spring  1  has a bulging  2  at only one end region, while the tapered portion, that is, the throat  4 , is continued into the other end region.  
         [0033]     Corresponding to this shaping-out, barrel spring  9  rests against a region of the throat  4 , which barrel spring  9  is constructed as a pocket spring and whose pocket is connected with the pocket of the spring  1 , which connection may be by a gluing-together.  
         [0034]     In this case, the barrel spring  9  projects over the spring  1 , on a side situated opposite the bulging  2 , so that, for example, a turner mattress is formed whose spring characteristic differs on the two sides.  
         [0035]     The rows can be connected, for example, by cover layers  10  which include a nonwoven covering and are connected on one side with the bulging-out springs  1  and, on the other side, with the barrel springs  9 . By different spring characteristics of the two usage sides, different lying characteristics are obtained so that individual wishes can be taken into account.  
         [0036]      FIGS. 5 and 6  show a connection region as an individual unit, by which the fabric strips covering the individual springs  1  on both sides are connected with one another between two springs  1 . In this manner, the pockets  5  are formed.  
         [0037]     As shown in  FIGS. 5 and 6 , the sealing seams  7  are arranged such that the springs  1  are firmly clamped into the pockets  5 , so that a lateral deflection is virtually excluded.  
         [0038]     While an intermediate region between the two exterior sealing seams  7 , which each bound a pocket  5  as shown in  FIG. 5 , is reinforced by additional sealing seams  7 , in the embodiment shown in  FIG. 6 , this intermediate region is free of such additional sealing seams  7 .  
         [0039]     A combination with other types of springs is also conceivable, depending on which lying characteristics are desired.  
         [0040]     Although the present disclosure has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The scope of the present disclosure is to be limited only by the terms of the appended claims.