GB2105583A - Mattress springs - Google Patents

Abstract

A spring 1 for a mattress comprises a plurality of spring steel helices a of opposite sense interwoven in the form of an elongate tube and connecting means 2 at each end of the spring connecting together the helices at that end. A mattress is sprung by a plurality of spring group units B comprising a number of such springs, the connecting means 2 at each end of the units being connected together by a plastics end cap. <IMAGE>

Description

SPECIFICATION Mattress or the like and springs therefor The present invention relates to mattresses or the like and is particularly concerned with mattresses which provide a good ventilation effect, that is to say they have a substantial amount of open space in their interior to minimise problems with perspiration or the like, and with springs for such mattresses.

Known mattresses generally incorporate a plurality of coil springs which are loaded along their length, that is to say the springs extend transverse to the support surface of the mattress.

It is also known to provide mattresses with a single spring support structure comprising a complex lattice work of spring steel, in the iatter case it is only practical to make the mattress of regular shape, e.g. rectangular or circular and in both bases the support force which can be exerted by the support springs or structure is substantially unidirectional. If such mattresses are twisted or bent or subjected to a substantial force in a direction other than substantially perpendicular to their support surface they may become permanently deformed and thus give irregular or inferior spring support and provide a reduced internal ventilation due to local contact within the mattress which can give rise to condensation or other problems caused by perspiration.

According to the present invention a spring for a mattress or the like comprises a plurality of spring steel helices of opposite sense interwoven in the form of an elongate tube and connecting means at each end of the spring connecting together the helices at that end.

Two or more such springs may be arranged side by side and connected together to form a spring group unit by connecting together the connecting means at the two ends of the unit.

The invention also embraces a mattress or the like in the interior of which is a plurality of such springs or spring group units each of which is connected to the mattress. Preferably each spring or each spring group unit is overlayed by a layer of material which is sewn to the mattress between each adjacent spring or spring group unit.

Preferably each spring or spring group unit is connected, e.g. sewn, to the layer of material, which may constitute the mattress cover.

The springs of the present invention are preferably arranged substantially parallel to the support surface of the mattress and are thus generally subjected to a force transverse to their length It will however be appreciated that by virtue of their interwoven helical structure they can also exert a spring force in the direction of their length and thus if the mattress is bent or twisted or subjected to forces at different angles the springs can exert an appropriate reactive force and the mattress is thus not permanently deformed or otherwise degraded.

Further features and details of the present invention will be apparent from the following description of one specific embodiment which is given by way of example only with reference to the accompanying drawings in which: Figure 1 is a partly cut-away perspective view of a mattress in accordance with the present invention; Figure 2 is a perspective view of a spring group unit in accordance with the invention for the mattress of Figure 1; Figure 3 is a perspective view of a spring in accordance with the invention for the spring group unit of Figure 2; and Figure 4 is an enlarged view of one end of the spring of Figure 3 showing how the ends of the helices are crimped together.

Figures 3 and 4 show an elongate tubular spring 1 which is formed by knitting or weaving a plurality of helices a of opposite sense of spring steel wire to form a tubular lattice. This tube may be produced continuously and is cut into desired lengths. After cutting, the helices at the two ends of the tube are connected together by a respective metallic clip 2 which is crimped around the ends of the helices. Thereafter a plastics shield cap 3 is placed over each clip 2 to protect any sharp edges and to ensure that the ends of the individual springs are always of the same size.

As seen in Figure 2, a number of these springs 1, in this case three, are then laid side by side and connected together at their ends by a plastics end cap 4 to form a spring group unit B.

As seen in Figure 1, a plurality of such spring group units B, B 1, B2 etc. are then laid side by side under a mattress cover 5 on a mattress. Each spring group unit is then connected to the cover 5 by sewing and the latter is connected by sewing to the mattress, as indicated by the dotted lines.

The springs and spring group units are suitable for use not only with mattresses but also with chairs, car seats, cushions and the like and in the context of the present invention the term "mattress" is to be interpreted accordingly. Such spring supports afford a substantially planar support surface and the springs and spring gap units are arranged so that their axis extends substantially parallel to this support surface with the result that the force applied to them is substantially transverse to the longitudinal axis.

Such springs and spring group units, which are preferably supported on their underside, are found to give a good, smooth supporting cushion effect and have a long service life. In addition each spring defines a large internal volume through which air may circulate thus minimising the possibility of condensation or other problems that may be caused by perspiration or other moisture.

Each spring or spring group unit is capable of exerting a spring force not only transverse to its length but also along its length by virtue of its elongate interwoven helical construction. A mattress or the like in accordance with the invention can therefore be twisted or deformed or subject to loads which act other than transverse to the length of the springs without its performance being substantially degraded as regards its spring support function and its ventilation ability and without its service life being substantially reduced.

When a localised load is applied to the mattress each spring or spring group unit is loaded along its entire length and thus the load is spread uniformly and the entire length of the springs thus contributes to the spring support. The mattress of the present invention is thus not prone to localised "soft spots" where the springs have become weakened by greater use.

Claims (9)

1. A spring for a mattress or the like comprising a plurality of spring steel helices of opposite sense interwoven in the form of an elongate tube and connecting means at each end of the spring connecting together the helices at that end.

2. A spring as claimed in Claim 1 in which the helices at each end of the spring are crimped together by a metallic clip.

3. A spring for a mattress or the like substantially as specifically herein described with reference to Figures 3 and 4 of the accompanying drawings.

4. A spring group unit for a mattress or the like including two or more springs as claimed in any one of claims 1 to 3 arranged side by side, the connecting means at the two ends of the unit being connected together.

5. A unit as claimed in claim 4 in which the first connecting means at the two ends of the unit are connected by means of a respective plastics end cap.

6. A mattress or the like in the interior of which is a plurality of springs as claimed in any one of claims 1 to 3, each spring being connected to the mattress.

7. A mattress or the like in the interior of which is a plurality of spring group units as claimed in claim 4 or claim 5, each unit being connected to the mattress.

8. A mattress as claimed in claim 6 or claim 7 in which each spring or each unit is overlayed by a layer of material which is sewn to the mattress between each adjacent spring or unit.

9. A mattress or the like substantially as specifically herein described with reference to the accompanying drawings.