The invention relates to a mattress base consisting of a rectangular frame, a plurality of slats disposed transversely at determined intervals, and spring members mounted between the ends of the slats and the longitudinal members of the frame.
The invention relates more particularly to the spring members making the connection between the ends of the slats and the longitudinal members of the frame.
Slatted mattress bases are a very practical and comfortable alternative to conventional spiral bed springs and box springs. Not only do they provide zonal distribution of hardness, but also offer greater stiffness.
The spring members by which the slats of a mattress base of this kind are connected to the longitudinal members have a great influence on the comfort of the bed. A stiff connection between the ends of the slats and the frame results in a hard, scarcely comfortable bed. Known spring members include rubber supports, which however have the disadvantage of limited life, flexibility and compressibility.
Leaf springs are a known alternative to rubber supports. These known leaf springs, as described in NL 8402221 and NL 8400147, consist mainly of a strip folded in V-shape. They have the disadvantage that on the one hand the places where the strip is folded are weak spots in respect of strength and life, and that on the other hand the slats supported on the V-shaped leaf springs can make only a vertical movement.
Another slatted mattress with spring members is described in DE-A-2364030, in which the spring members consisting of a leaf spring which shape has a middle part extending horizontally and supporting one slat, while the two side parts or legs are extending downwards towards one another to a central point under the middle point of the middle part of said leaf spring before further extending downwards one from the other to fasteners against the longitudinal member with a distance between them larger as the width of the supported slat. This system has the disadvantage to present a limited movement of the slats.
The aim of the mattress base according to the invention is to provide a bed which gives maximum comfort and which is built with constructionally simple and durable elements. The aim of the mattress base according to the invention is more particularly to increase the freedom of movement of the slats so that, while retaining maximum vertical yieldability, the slats can also tilt and undergo a certain horizontal displacement.
The mattress base according to the invention, consisting of a rectangular frame, a plurality of slats disposed transversaly at determined intervals, and spring members, which spring members consist of a leaf spring whose longitudinal axis is directed at right angles to the longitudinal axis of the slats, and whose shape consists substantially of three parts, a middle part which extends substantially horizontally and on which the ends of one or more slats are supported, and two side parts which form the ends of the leaf spring caracterized in that said side parts, starting from the middle part, extend progressively downwards before turning and coming towards each other to be rigidly connected to the longitudinal member at a distance apart smaller than the width of the middle part.
Further details of the mattress base according to the invention will emerge from the following description of one possible form of construction of the mattress base according to the invention, as an example not constituting a limitation. This description is given with reference to the accompanying drawings, in which:
As illustrated in Figures 1 and 2, the slatted base according to the invention consists substantially of a frame, whose longitudinal members 1 carry the slats 2 via spring members 3. A spring member of this kind is made from a strip of metal and has a shape such that the middle part 4, on which one or more slats 2 are fastened, extends substantially horizontally and that starting from the middle part 4 the ends 5 first extend downwards and then, after extending towards each other over a certain distance 6, extend back upwards to pass into the fastener 7. The fastener 7 is fastened by two studs 8, each of which fits into a tapped hole in the longitudinal member 1 of the frame, against the inner face of the longitudinal member 1. The fastener 7 is provided with two grooves 9. The end 5 of a spring member 3 can be inserted over its entire width into a groove 9. To ensure optimum, rigid fastening between the spring member 3 and the fastener 7, each end 5 is provided with a hook 10 and the groove 9 is shaped accordingly.
In view of the fact that the width of the middle part 4 is greater than the distance between the points where the ends 5 pass out of the groove 9 in the fastener 7, and because of the rigid connection between the ends 5 and the fastener 7, the spring member 3 can, through the action of the load on the slats 2, not only make a vertical yielding movement but also make a tilting movement about the fastener 7 and undergo a certain horizontal displacement. In this way the slats 2 are given maximum freedom of movement, which results in increased comfort of the bed. On the other hand, the spring member 3 has no single weak point because of its rounded shape. The simple fastening between the fastener 7 and the longitudinal member 1 enables the height of the slats 2 to be adjusted in a simple manner, in the state of rest, to the shape of the body. It is sufficient to fasten the studs 8 of the fasteners 7 at a different height on the longitudinal members 1.
The connection between a slat 2 and the spring member 3 is achieved with the aid of a connector 11, preferably made of plastics material (see Figures 1 and 2). A connector 11 of this kind consists substantially of a chamber 12 embracing the end of a slat 2 and provided at the bottom with a long lip 13, behind which the middle part 4 of the spring member 3 can be pushed (see Figures 3 and 4). The middle part 4 may be provided with a depression 14 in the place where a connector 11 is situated, so that lateral displacement of the slat 2 in relation to the spring member 3 is prevented (see Figure 1).
In the mattress base according to the invention two types of connector 11 are provided; the first type has a buffer block 15 (Figures 1, 2 and 4), while the second has no buffer block (Figure 3). The buffer block 15 is fastened against the chamber 12 of the connector 11, in front of the end of the slat 2, so that it comes to lie above the longitudinal member 1 (Figure 2). The yieldability of a spring member 3 whose connectors 11 are provided with a buffer block 15 is thus limited to the distance between the buffer block 15 and the top face of the longitudinal member 1. Buffer blocks 15 of this type are provided in a middle zone of the mattress base according to the invention. The type not provided with a buffer block (Figure 3) allows greater yieldability because the slat 2 can in this case be pressed in inside the longitudinal member 1. Connectors 11 of this type which have no buffer blocks 15 are provided in the shoulder zone of the mattress base according to the invention. Under the head and the feet the slats 2 are rigidly connected to the longitudinal members 1. In this way the hardness of the bed can be adapted to the support required by a determined part of the body.
It is obvious that the shape of the spring members 3 is not restricted to that shown in the drawings. Thus, the ends 5 of a spring member 3 may be seated in separate fasteners. The ends 5 may also be Joined to the longitudinal members 1 at a greater distance apart. A spring member 3 may also carry only one slat 2, so that the middle part 4 is narrower and is provided with only one depression 14.