Patent Publication Number: US-6701550-B2

Title: Slatted frame for reclining furniture

Description:
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/CH01/00215 which has an International filing date of Apr. 3, 2001, which designated the United States of America. 
     1. Technical Field 
     The present invention relates to a slatted base for furniture for lying on according to the preamble of the independent patent claim, it being possible for the slatted base to be positioned, in particular, in the framework of a piece of furniture for lying on. 
     2. Prior Art 
     BICO Birchler &amp; Co. AG&#39;s European Patent Application EP-A1-0 761 138 describes a slatted base for furniture for lying on. Since the resilient-slat-bearing longitudinal supports, which are designed as outer longitudinal spars of a slatted-base frame, are inclined inward, space is provided for fitting supporting bodies for the resilient slats on the outer side of the longitudinal supports. These supporting bodies are produced from hard plastic and elastomeric material. Since, on the one hand, the entire overall height of a slatted base which can be positioned in a bedstead is limited by the dimensions of the bedstead and, on the other hand, the supporting bodies of the slatted base according to EP-A1-0 761 138 are arranged at least partially over the longitudinal supports, the level of resilient deflection which is available for the slats in the region of the longitudinal supports is relatively low. 
     DESCRIPTION OF THE INVENTION 
     The object of the present invention is to specify a slatted base which, on the one hand, is of a low overall height and, on the other hand, ensures a high level of resilient deflection for the slats, in particular also in the region of the longitudinal supports bearing the slats. 
     The object is achieved by the features of claim  1 . According to the invention, a slatted base for furniture for lying on has two longitudinally running, essentially parallel longitudinal supports with mutually facing inner sides. The terms “inner” and “outer” should always be understood, in the present context, in respect of the slatted base. The slatted base also has a plurality of slats which are spaced apart transversely to the longitudinal supports and together form a bearing surface for a mattress. The slats are connected to the longitudinal supports by means of [sic] essentially two-legged leaf-spring elements, in each case one leg of a leaf-spring element being fitted on one of the slats and the other leg of said leaf-spring element being fitted on the inner side of one of the longitudinal supports. 
     A two-legged leaf-spring element should be understood, in conjunction with the present description and the patent claims, as a spring element which has two legs in the manner of leaf springs which has a leaf-like or strip-like, essentially flat structure. 
     Since, according to the invention, the slats are connected to the longitudinal supports, or are borne thereon, by means of flat, leaf-spring-like elements which are fitted on the side surface of the longitudinal supports, the connecting elements require just a small amount of space in the spring-movement direction, i.e. essentially transverse to the longitudinal direction of the supports and to the longitudinal direction of the slats. The space required in the spring-movement direction by said flat leaf-spring elements in the region of the longitudinal supports corresponds essentially to the thickness of the spring legs fitted on the slats. This small amount of space which is required is advantageous, in particular, in slatted-base structures in which the spring legs fitted on the slats are arranged partially between the slats and the longitudinal supports and, by virtue of the slatted base being subjected to loading, are pressed down onto said longitudinal supports. 
     According to a preferred manner of implementing the invention, in the case of a slatted base, at least one of the leaf-spring elements is arranged such that its spring leg which is fitted on the longitudinal support extends, from the region in which it is fitted on the longitudinal support, in a direction which, in relation to the plane defined by the two longitudinal supports, is inclined toward the slat which is connected to the leaf-spring element. It is preferable for even all of the leaf-spring elements to be arranged in this way. 
     The slatted base, or the slatted-base plane defined by the two longitudinal supports, is usually arranged essentially horizontally. In this case, the spring leg extends, in the region of the longitudinal support, obliquely upward from the longitudinal support. As a result, in the case of a horizontal arrangement of the slatted base, the force to which the two longitudinal supports are subjected by the spring elements, which are subjected to loading essentially vertically from above by the slats, is introduced obliquely downward rather than, as is conventional, either in the horizontal direction or in the vertical direction. This geometrical arrangement of the slats, of the leaf-spring elements and of the longitudinal supports relative to one another is particularly well adapted to the present situation. The angle of inclination between the spring legs and the (usually horizontal) plane defined by the two longitudinal supports in the region in which the spring legs are fitted on the longitudinal supports is preferably between 5 and 80 degrees, angles of inclination between 20 and 45 degrees, in particular angles of inclination of approximately 30 degrees, being particularly preferred. 
     A leaf-spring element of a slatted base according to the invention preferably has an essentially U-shaped configuration with two leg sections and a web section connecting these two leg sections. In this case, the spring element is preferably fitted on the slatted base such that the web section is arranged in the interior of the slatted base (i.e. between the two longitudinal supports), with the result that the two leg sections extend outward, from the web section, toward the locations at which they are respectively fitted on the slat and on the inner side of the longitudinal support. 
     The leaf-spring elements of a slatted base according to the invention may be produced from glass-fiber-reinforced plastic, it being possible for the glass fibers to be arranged such that they run at least partially in a unidirectional manner, preferably ever wholly in a unidirectional manner, in the longitudinal direction of the leaf-spring elements. Leaf-spring elements made of glass-fiber-reinforced plastic are distinguished by a particularly long service life. They are not subject to fatigue even after years of constant use. As an alternative to leaf-spring elements made of glass-fiber-reinforced plastic, it is also possible for the spring elements to be produced from spring sheet steel or from other materials which are suitable for leaf springs. 
     The inner side of a longitudinal support of a slatted base according to the invention is preferably provided with spring-securing means which are designed such that one or more of the leaf-spring elements can be fitted therein. The spring-securing means may be designed as integral constituent parts of the longitudinal support, or they may be fitted as separate parts on the inner side of the longitudinal support. They may be produced from plastic, from spring sheet steel, from aluminum or from other suitable materials. 
     According to a preferred manner of implementing the invention, the spring-securing means comprise a hollow profile, preferably an extruded aluminum profile, which is arranged on the inner side of one longitudinal support, a groove being formed in the profile wall of the latter which is directed toward the other longitudinal support, and the groove being suitable for accommodating those leg ends of the leaf-spring elements which are to be fitted on said spring-securing means. It is possible here for the profile wall of the hollow profile which is directed toward the other longitudinal support to be essentially planar and, in relation to the (usually horizontal) plane defined by the two longitudinal supports, to enclose an angle which is 10-85 degrees, preferably 45-70 degrees, in particular approximately 60 degrees, the groove in the wall on the inner side of the profile preferably being formed at right angles to the surface of said inner profile wall. In the case of an angle of approximately 60 degrees, a spring leg accommodated in the groove then extends at an angle of approximately 30 degrees, in relation to the horizontal, away from the hollow profile and/or from the longitudinal support on which it is fitted. 
     The slatted base is preferably further provided with a hollow profile which is arranged at the head end and/or at the foot end of the slatted base, transversely to the longitudinal supports, has the same cross section as the hollow profile which is arranged on the longitudinal support and is provided with a groove which is suitable for accommodating a handle. This handle, for example for drawing an adjustable slatted-base section upward, may be provided at the head end of the slatted base. 
     According to a further preferred manner of implementing the invention, at least two adjacent slats of the slatted base are connected to one another by connecting means in order to provide a coupling between adjacent slats which is advantageous for furniture for lying on Such a slatted base may further be provided with a mattress holder, which can be fitted on the connecting means. 
     According to a preferred manner of implementing the invention, a longitudinal support of a slatted base comprises a spar made of laminated wood, the entire longitudinal support and, in particular, the spar being dimensioned such that the support height over the entire length is less than approximately 50 mm, preferably less than approximately 45 mm, in particular even less than approximately 40 mm. A spar made of wood gives a warm homely impression which is particularly preferred for furniture for lying on. Nevertheless, on account of the low overall height, it is well-suited for a slatted base which is provided for positioning in a furniture framework. For the purpose of stiffening the spar structurally, said spar may be provided with one or more reinforcing strips which is/are fitted on its top side and/or on its underside and has/have carbon fibers running in the longitudinal direction of the spar. This makes it possible to produce stiff wooden spars of a particularly low overall height. This aspect of the invention also proves to be advantageous without the use of essentially two-legged leaf-spring elements for connecting the slats to the longitudinal supports if it is desired to produce a slatted base of as low an installation height as possible. 
     However, other variants of longitudinal supports are also possible. It is thus possible, for example, to provide, for the support, a single hollow profile which is designed such that it is simultaneously provided with suitable locations at which the leaf-spring elements are fitted. Alternatively, the support may have a laminated-wood spar which is of low overall height and does not have any reinforcing strips made of carbon fibers or other suitable fibers, a hollow profile nevertheless being arranged on the inner side of the spar such that, on the one hand, it helps to stiffen and reinforce the support structure formed from the spar and the hollow profile and, on the other hand, it serves for accommodating the leaf-spring elements which are to be fitted on the support. 
     A longitudinal support of a slatted base according to the invention, comprising a spar made of laminated wood, preferably has a first section, in which the spar is fixed, essentially over the entire length, to a first single-piece hollow profile which is fitted on the inner side of the spar and is designed as a spring-securing means. The longitudinal support comprises a second section, in which a second single-piece hollow profile, which again is designed as a spring-securing means, is arranged on the inner side of the spar. The second hollow profile is articulated on the first hollow profile such that it can be pivoted about a transverse axis located essentially in the plane defined by the two longitudinal supports. The second longitudinal support of the slatted base is designed analogously, with the result that the slats which are connected to the second hollow profile form a slatted-base section which can be adjusted in relation to the slats which are connected to the first hollow profile. The slatted-base section which can be adjusted in relation to the stationary slats, connected to the first support section, can be used, for example, for ensuring that the head can be raised up. 
     According to a further preferred variant of the invention, a slatted base having two longitudinally running, essentially parallel longitudinal supports, and having a plurality of spaced-apart slats which are arranged transversely to the longitudinal supports and together form a bearing surface for a mattress, is further provided with a supporting-spring arrangement which comprises at least one supporting-spring element which is arranged beneath at least one slat such that it supports the slat, in a central region between the longitudinal supports, by means of spring force. In this case, the supporting-spring element is mounted either on at least one of the two longitudinal supports or on a transverse strut fitted on the two longitudinal supports, and thus supports the slat indirectly at this bearing location. Such a supporting-spring arrangement allows additional resilient or elastic support of the slats in a central zone of the slatted base. It is thus also referred to hereinbelow is hereinbelow [sic] as central-zone reinforcement. Obviously, this aspect of the invention does not absolutely have to be used in conjunction with the use of essentially two-legged leaf-spring elements for connecting the slats to the longitudinal supports. 
     A supporting-spring arrangement (or a central-zone reinforcement) for a slatted base preferably comprises at least one supporting-spring element which is designed such that it can be arranged beneath at least one slat of the slatted base such that it supports the slat, in a central region between two longitudinal supports of the slatted base, by means of spring force, it being possible for the supporting-spring element to be mounted either on at least one of the two longitudinal supports or on a transverse strut fitted on the two longitudinal supports, and thus for the slat to be supported indirectly at this bearing location. The supporting-spring element may be designed as a leaf-spring element, it being possible for said leaf-spring element to comprise two elongate leaf-spring arms arranged at an angle to one another, with the result that the supporting-spring element is of essentially V-shaped design. Such a V-shaped leaf-spring element may be arranged on the slatted base such that it is mounted on a transverse strut of the slatted base in the region of the connecting angle between the two spring arms and supports the slat from beneath in the region of the longitudinal end [sic] of the arms, said ends being remote from the connecting angle. However, supporting-spring elements which are differently designed and/or are arranged differently on the slatted base are also possible in principle. A central-zone reinforcement may also comprise, for example, a helical spring which is mounted on a transverse strut of the slatted base and supports a slat from beneath. 
     A supporting-spring arrangement (or a central-zone reinforcement) for a slatted base preferably further comprises means for optionally adjusting the spring force of the supporting-spring element. In the case of a supporting-spring arrangement with a V-shaped supporting-spring element, said spring-adjusting means may comprise, for example, an adjusting screw by means of which the angle between the two spring arms can be adjusted in order to prestress said spring arms and thus to adjust the slat-supporting spring force of the supporting-spring element. However, other suitable means for adjusting the spring force may also be provided in principle. It is thus also possible, for example, to use a device for adjusting the bearing location of the supporting-spring element on the transverse strut or on the longitudinal supports of the slatted base in order optionally to change the prestressing of the supporting-spring element. 
     Further advantageous embodiments and combinations of features of the invention can be gathered from the following detailed description and from the patent claims taken as a whole. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings used for explaining exemplary embodiments: 
     FIG. 1 shows a simplified cross-sectional view of part of a slatted base according to a first preferred manner of implementing the invention; 
     FIG. 2 shows a simplified perspective view, sectioned in a longitudinal direction, of part of the slatted base from FIG. 1; 
     FIG. 3 shows a simplified perspective view of part of a slatted base according to a further preferred manner of implementing the invention; 
     FIG. 4 shows a simplified cross-sectional view of part of the slatted base from FIG. 3; and 
     FIG. 5 shows a further simplified perspective view of part of the slatted base from FIG.  3 . 
    
    
     The same parts are basically provided with the same designations in the figures. 
     METHODS OF IMPLEMENTING THE INVENTION 
     The slatted base for furniture for lying on which is illustrated in FIGS. 1 and 2 comprises two essentially parallel longitudinal supports  50 , of which just one is illustrated in the partial views of FIGS. 1 and 2. The two supports  50  are connected by means of a plurality of transverse struts  52  (of which just one is illustrated, by way of example, in the figures) to form a frame which bears a plurality of spaced-apart slats  10 ,  11 ,  71 ,  72  which are arranged transversely to the longitudinal supports. These slats  10 ,  11 ,  71 ,  72  are connected to the longitudinal supports  50  by means of essentially two-legged leaf-spring elements  20 ,  81 ,  82 , in each case one leg  22  of a leaf-spring element  20  being fitted on one of the slats  10  and the other leg  23  of said leaf-spring element  20  being fitted on the inner side  32  of one of the longitudinal supports  50 . The slats  10 ,  11 ,  71 ,  72  together form a bearing surface for a mattress. As usual, the slatted base illustrated in the figures is arranged such that the bearing surface for the mattress (and thus also the plane  54  defined by the two parallel longitudinal supports as well as the slats  10 ,  11 ,  71 ,  72 ) are located essentially horizontally. 
     The longitudinal support  50 , which is illustrated in FIGS. 1 and 2, comprises a beam-like spar  40  which is produced from laminated wood and is of a rectangular cross section which is essentially constant over the entire length. The height of the spar is approximately 40 mm. In each case one carbon-fiber-containing strip  44 ,  42  is fitted on the top side and on the underside of the spar in order to reinforce and/or stiffen the spar  40  structurally. 
     On the inner side of the spar  40 , which is directed toward the other longitudinal support, hollow profiles  30 ,  38  in the form of extruded aluminum profiles  30 ,  38  are arranged essentially over the entire length. These extruded aluminum profiles  30 ,  38 , on the one hand, have a load-bearing function and form part of the longitudinal support  50 , which essentially comprises the spar  40  and the extruded aluminum profiles  30 ,  38 . The extruded aluminum profiles  30 ,  38 , on the other hand, serve as spring-securing means  30 ,  38  which are designed such that the leaf-spring elements  20 ,  81 ,  82  can be fitted therein. 
     The longitudinal support  50  has a first longitudinal section  56 , in which the spar  40  is fixed essentially over the entire length to a first single-piece hollow profile  30  (an extruded aluminum profile  30  which is designed, at the same time, as a spring-securing means  30 ) which is fitted on its inner side. FIG. 1 illustrates a cross section through said first longitudinal section  56 . As can be seen in FIG. 1, two longitudinally running grooves are formed on the inner side of the spar  40 . The first hollow profile  30  is provided with two corresponding combs  33 ,  34 , which are plugged into the grooves, formed on the inner side of the spar, in order to fasten the profile  30  on the spar  40 . 
     The longitudinal support  50  has a second longitudinal section  58 . In this second longitudinal section  58 , a second single-piece hollow profile  38  (once again an extruded aluminum profile  38  which is designed, at the same time, as a spring-securing means  38 ) is arranged on the inner side of the spar  40 . In contrast to the first hollow profile  30 , the second hollow profile  38  in the second longitudinal support section  58 , rather than being connected to the spar  40 , can be moved in relation to the same. The second hollow profile  38  is articulated on the first hollow profile  30  such that it can be pivoted about an essentially horizontal transverse axis  39 . The second longitudinal support (not illustrated) of the slatted base is designed analogously such that the second hollow profiles  38 , which are articulated on the support spars  40  such that they can be pivoted about the transverse axis  39 , together with the slats  71 ,  72  fitted on them and/or connected to them form a slatted-base section which can be adjusted in relation to the support spars  40  (and thus in relation to the slats  10 ,  11 , which are connected to the first hollow profiles  30 ), the two pivotable hollow profiles  38  being connected to one another by means of a hollow profile  37  which connects the hollow profiles transversely to one another and serves as a transverse strut  37 . Said transverse strut  37 , in the form of a hollow profile, is arranged at the head end of the slatted base. The adjustable slatted-base section is designed for ensuring that the head can be raised up, it being possible for it to be adjusted by means of an adjusting mechanism  60  conventional for slatted bases and to be arrested in the desired position 
     FIG. 1 illustrates in cross section, by way of example, a connecting arrangement for connecting a slat  10  to one longitudinal support  50 . Dashed lines likewise illustrate a connecting strut  52  between the two longitudinal supports  50 , said connecting strut being located outside the section plane. The first hollow profile  30 , which is fixed on the inner side of the support spar  40 , has an essentially planar profile wall  32 , which is directed toward the other longitudinal support and is referred to hereinbelow as the inner wall  32  of the hollow profile  30 . This inner wall  32  of the hollow profile  30 , at the same time, forms the inner side  32  of the longitudinal support  50 , comprising the spar  40  and the extruded aluminum profile  30 . The inner wall  32  of the hollow profile  30  (or the inner side  32  of the longitudinal support  50 ) is inclined outward in the upward direction in relation to the horizontal  54  (i.e. in relation to the plane  54  which is defined by the two longitudinal supports  50  and is illustrated by a dashed line in FIG.  1 ), the angle α enclosed between the horizontal  54  and the wall  32  on the inner side of the profile being approximately 60 degrees. 
     Formed in the wall  32  on the inner side of the hollow profile  30  is a groove  35  which runs in a longitudinal direction of the profile and is intended for accommodating the spring legs  23  of the leaf-spring elements  20 , the groove cross section running essentially at right angles to the surface of the inner profile wall  32 . 
     The leaf-spring element  20 , which is illustrated in the cross-sectional illustration of FIG. 1, has an essentially U-shaped configuration with two leg sections  22 ,  23  and a web section  21  connecting these two leg sections  22 ,  23 . The leaf-spring element  20  is produced from glass-fiber-reinforced plastic, the glass fibers being arranged such that they run at least partially in a unidirectional manner in the longitudinal direction of the leaf-spring element  20 . 
     The leaf-spring element  20  is arranged on the slatted base such that the web section  21  is located in the interior of the slatted base, i.e. between the two parallel longitudinal supports  50 . The leg section  23 , which is fitted on the longitudinal support  50 , extends obliquely outward in the downward direction from the web section  21 , the end of said spring leg  23  being accommodated in the groove  35 , formed in the inner profile wall  32 , such that, in relation to the horizontal  54 , the angle of inclination β of said spring leg  23  is approximately 30 degrees in the region in which it is fitted on the inner profile wall  32 . In the manner of implementing the invention which is illustrated in FIGS. 1 and 2, said spring-leg end is provided with a thickened portion  25  made of an elastic material, in order to allow the spring-leg end to be plugged into the groove  35  in a snugly fitting manner. 
     However, other variants for fitting the spring elements on the longitudinal support are also possible. It is thus possible, for example, for the spring-leg end to be bent through approximately 180 degrees in its end region in order that the curved-over end forms a restraining spring which can be latched into a groove provided with a protrusion on its border, such that the restraining spring latched in behind the protrusion prevents the spring leg from being drawn out of the groove. 
     The leg section  22 , which is fitted on the slat  10 , extends obliquely outward in the upward direction from the web section  21 . The end of this spring leg  22  runs essentially horizontally in the region of the longitudinal end of the slat  10  and butts against the underside of the slat, the slat  10  and the slat-side spring-leg end being held together by a plastic cap  15 . For the assembly of the slatted base, this spring-leg end  22  can simply be plugged in between the underside of the slat and the plastic cap  15 , whereupon it is clamped firmly between the slat  10  and the plastic cap  15 . If the slat  10  is pressed downward, and the leaf-spring element  20  is bent, by the slatted base being subjected to loading, then the slat-side spring leg  22  rolls on the underside of the slat  10  without producing any aggravating noise. 
     In the case of the slatted base illustrated in FIGS. 1 and 2, pairs of two adjacent slats  10 ,  11  of the slatted base are coupled to one another in each case. The plastic cap  15 , by means of which the slat  10  is connected in the region of one of its longitudinal ends, on one side of the slatted base, to the leaf-spring element  20 , is connected, via a connecting web  17 , to the plastic cap  16  of an adjacent slat  11  on the same side of the slatted base. Analogously, the plastic caps of the slats  10 ,  11  are also connected to one another, in the region of their longitudinal ends, on the other side of the slatted base. The connecting web  17  is produced from an elastic material. In the exemplary embodiment of the invention which is illustrated in FIGS. 1 and 2, the two adjacent plastic caps  15 ,  16  and the connecting web  17  which connects them are formed as a single-piece plastic part from an elastic polymer material. Connecting pairs of adjacent slats  10 ,  11  of the slatted base in an elastic manner achieves a coupling between the individual slats of the slatted base which is advantageous for furniture for lying on. 
     However, other variants for fitting the spring elements on the slats are also possible. It is thus possible, for example, for the slat-side spring-leg end to be angled and to enclose the slat end wholly or at least partially, in order to connect the slat to the leaf-spring element. 
     The hollow profile  37 , which is arranged at the head end of the slatted base and by means of which the two hollow profiles  38 , which are articulated on the support spars  40 , are connected to one another in the manner of a transverse strut  37 , is likewise an extruded aluminum profile and is of essentially the same profile cross section as the two hollow profiles  38 , which are articulated on the support spars  40 . Formed, once again, in that profile wall of said hollow-profile-like transverse strut  37  which is on the inside in relation to the slatted base is a groove  36  which runs in the longitudinal direction of the profile. A handle (not illustrated) for drawing the adjustable slatted-base section upward can be fitted in said groove  36  at the head end of the slatted base in the same manner as the leaf-spring element  20  is fitted in the groove  35 , which is formed in the inner wall  32  of the hollow profile  30 , which is fitted on the spar  40  of the longitudinal support  50 . 
     FIGS. 3 to  5  illustrate a slatted base according to a further preferred manner of implementing the invention. Two mutually parallel supports  150 ,  250  are connected to one another by means of transverse struts  152 ,  153  to form a frame which bears a plurality of spaced-apart slats  110 ,  111 ,  171 ,  172  which are arranged transversely to the longitudinal supports  150 ,  250 . The longitudinal supports  150 ,  250 , once again, each comprise a spar  140 ,  240  produced from laminated wood, extruded aluminum profiles  130  being fitted on the inner sides of said spars  140 ,  240  and serving, on the one hand, as securing means for the leaf-spring elements  120 , which bear the slats  110 ,  111 ,  171 ,  172 , and, on the other hand, for reinforcing the spars  140 ,  240 . In contrast to the slatted base illustrated in FIGS. 1 and 2, the spars  140 ,  240  of the slatted base illustrated in FIGS. 3 to  5  are not provided with carbon-fiber-containing reinforcing strips. Instead, the spars  140 ,  240  illustrated in FIGS. 3 to  5  are of greater dimensions than the spars  40  illustrated in FIGS. 1 and 2. In the exemplary embodiment illustrated in FIGS. 3 to  5 , the spars  140 ,  240  are each of rectangular cross section with a height of 50 mm and a width of 25 mm. Otherwise, the extruded aluminum profiles  130 , the slats  110 ,  111 ,  171 ,  172 , the leaf-spring elements  120 , the plastic caps  115 ,  116 ,  215 ,  216  and the connecting webs  117 ,  217  of the slatted base illustrated in FIGS. 3 to  5  are designed, and arranged on the slatted base, in the same way as the corresponding components of the slatted base illustrated in FIGS. 1 and 2. 
     FIG. 5, furthermore, illustrates a mattress holder  218 , which serves for laterally securing a mattress (not illustrated) resting on the slatted base. The mattress holder  218  has a foot part  219  provided with a horizontal transverse slot. The foot part  219  and the transverse slot formed therein are dimensioned such that the foot part  219  together with the mattress holder  218  can be pushed from the inside of the slatted base onto the connecting web  217  between the plastic caps  215 ,  216 , which are connected to one another by said connecting web  217 , until it is positioned against the connecting web  217  by way of its inner slot end and is then secured with clamping action on the connecting web  217 . This design means that the mattress holder  218  may optionally be fitted on the slatted base and removed again. In the fitted state, it moves along with the slats  110 ,  111 , which are fitted compliantly on the slatted-base frame by means of the leaf-spring elements  120 , and reliably prevents the mattress from being displaced laterally beyond the side border of the slatted base. 
     The slatted base illustrated in FIGS. 3 to  5  is further provided with an arrangement for adjusting the elasticity of the slatted base if (or the resilient supporting force of the slatted base) in a central region of the slatted base. This supporting-spring arrangement, also referred to as central-zone reinforcement, is illustrated in a simplified perspective partial view in FIG.  3  and in cross section in FIG.  4 . 
     The central-zone reinforcement comprises a plurality of two-armed elongate leaf-spring elements  162 ,  163 , referred to hereinbelow as supporting springs  162 ,  163 , which extend essentially transversely to the longitudinal direction of the slatted base, said longitudinal direction being defined by the longitudinal supports  150 ,  250 , and are each mounted on a transverse strut  152 ,  153  of the slatted base. In each case one transverse strut  152 ,  153  together with the supporting spring  162 ,  163  borne by it is arranged centrally beneath a pair of adjacent slats  110 ,  111 , which are coupled to one another by means of the plastic caps  115 ,  116 ,  215 ,  216 , which are connected to one another by the connecting webs  117 ,  217 . For the sake of clarity, the illustration of FIG. 3 has omitted the slats  171 ,  172  over one of the supporting springs  163  illustrated and has depicted the slats  110 ,  111  over the other supporting springs  162  illustrated. 
     In the exemplary embodiment of the invention which is illustrated in FIGS. 3 to  5 , the supporting springs  162 ,  163  are produced from the same material as the spring elements  120  which connect the slats  110 ,  111 ,  171 ,  172  to longitudinal supports, namely from glass-fiber-reinforced plastic, the glass fibers being arranged such that they run at least partially in a unidirectional manner, preferably even wholly in a unidirectional manner, in a longitudinal direction of the supporting springs  162 ,  163 . As an alternative, however, it is also possible for the supporting springs to be produced from spring sheet steel or from other materials which are suitable for leaf springs. 
     The elongate transverse strut  153  illustrated in cross section in FIG. 4 is designed as a hollow aluminum profile  153 . An elongate recess  170  is formed in the top wall  173  of said hollow profile  153 , approximately in the longitudinal center. In the region of the two longitudinal borders of said recess  170 , the top wall  173  of the hollow aluminum profile  153  is routed downward, in the form of an arc of a circle, onto the base wall of the hollow aluminum profile  153  and defines there two supporting surfaces  176 ,  177  which are curved upward toward the recess  170 . In each case one arm  166 ,  167  of the supporting spring  163  is mounted on said two supporting surfaces and is supported on the hollow aluminum profile  153  by the supporting surface  176 ,  177 . 
     Arranged centrally above the recess  170 , formed in the top wall  173  of the hollow aluminum profile  153 , is a cover part  175 , which is fixed to the two side walls of the hollow aluminum profile  153 . Formed in said cover part  175  is a vertical bore which is provided with an internal thread. Accommodated in the bore is an adjusting screw  165 , which is provided with an external thread corresponding to the internal thread of the bore. 
     The essentially V-shaped supporting spring  163  rests, by way of its two connecting arms  166 ,  167 , on one of the supporting surfaces  176 ,  177  in each case such that the two arms  166 ,  167  of the supporting spring  163  each extend, from the supporting surfaces  176 ,  177  defining the longitudinal borders of the recess  170 , upward and outward in the direction of the side borders of the slatted base. In each case one elongate supporting element  181 ,  182  is fitted at the outer ends of the arms  166 ,  167 . The supporting elements  181 ,  182  are arranged on the arms  166 ,  167  of the supporting spring  163  such that they extend essentially parallel to the longitudinal direction of the slatted base (i.e. transversely to the slats  110 ,  111 ,  171 ,  172 ) and support from beneath the two slats  171 ,  172  of the pair of slats arranged above the supporting spring  163 , the supporting elements  181 ,  182  being designed such that the slats  171 ,  172  can easily slide on them. 
     The connecting section between the two arms  166 ,  167  of the supporting spring  163  is routed through beneath the cover part  175  and the adjusting screw  165 , the curvature of said connecting section being dimensioned such that the supporting spring  163  between the two supporting surfaces  176 ,  177 , although routed through beneath the adjusting screw  165 , does not extend down as far as the base of the hollow aluminum profile  153 . By means of the adjusting screw  165 , then, it is possible for the connecting section of the supporting spring  163  to be optionally subjected to loading from above and pressed downward or relieved of loading again in relation to the aluminum profile  153 , on which the supporting spring  163  is mounted. If the adjusting screw  165  is screwed downward and the connecting section of the supporting spring  163  is thus pressed downward, toward the base of the aluminum profile  153 , there is a reduction in the radius of curvature of the connecting section between the two arms  166 ,  167  of the supporting spring  163 . The outer ends of the two arms  166 ,  167  of the supporting spring  163  are consequently raised and/or pressed upward to a pronounced extent, with the result that the supporting elements  181 ,  182 , which are fitted at said outer ends, subject the slats  171 ,  172  arranged above them to a greater supporting force. Conversely, the supporting force to which the slats  171 ,  172  are subjected by the supporting elements  181 ,  182  is reduced when the adjusting screw  165  is screwed upward and there is thus an increase in the radius of curvature of the connecting section between the two arms  166 ,  167  of the supporting spring  163 . This ensures stepless regulation of the elastic spring force of the slatted base by means of the central-zone reinforcement in a central zone of the slatted base. 
     In summary, it may be stated that the invention provides a slatted base for furniture for lying on which, on the one hand, is of a low overall height and is thus suitable for positioning in a framework of a piece of furniture for lying on and which, on the other hand, provides a high level of resilient deflection for the slats, in particular also in the region of the slat-bearing longitudinal supports. 
     
       
         
           
               
             
               
                   
               
               
                 List of designations 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 10, 11, 71, 72, 
                 Slat 
               
               
                   
                 110, 111, 171, 
               
               
                   
                 172 
               
               
                   
                 15, 16, 115, 
                 Plastic cap 
               
               
                   
                 116, 215, 216 
               
               
                   
                 17, 117, 217 
                 Connecting web 
               
               
                   
                 20, 81, 82 
                 Leaf-spring element 
               
               
                   
                 21 
                 Web section 
               
               
                   
                 22, 23 
                 Leg section, spring leg 
               
               
                   
                 25 
                 Thickened portion of the spring-leg 
               
               
                   
                   
                 end 
               
               
                   
                 30, 38, 130 
                 Hollow profile 
               
               
                   
                 32 
                 Inner side of the hollow profile 
               
               
                   
                   
                 and/or of the support 
               
               
                   
                 33, 34 
                 Comb 
               
               
                   
                 35, 36 
                 Groove 
               
               
                   
                 37 
                 Transverse strut in the form of a 
               
               
                   
                   
                 hollow profile 
               
               
                   
                 39 
                 Articulation axis 
               
               
                   
                 40, 140, 240 
                 Spar 
               
               
                   
                 42, 44 
                 Carbon-fiber strip 
               
               
                   
                 50, 150, 250 
                 Longitudinal support 
               
               
                   
                 52, 152, 153 
                 Transverse strut 
               
               
                   
                 54 
                 Horizontal plane 
               
               
                   
                 56, 58 
                 Longitudinal support section 
               
               
                   
                 60 
                 Adjusting mechanism 
               
               
                   
                 162, 163 
                 Supporting spring 
               
               
                   
                 165 
                 Adjusting screw 
               
               
                   
                 166, 167 
                 Spring arm 
               
               
                   
                 170 
                 Recess 
               
               
                   
                 173 
                 Top wall 
               
               
                   
                 175 
                 Cover part 
               
               
                   
                 176, 177 
                 Supporting surface 
               
               
                   
                 181, 182 
                 Supporting element 
               
               
                   
                 218 
                 Mattress holder 
               
               
                   
                 219 
                 Foot part of the mattress holder