U.S. patent application number 12/095882 was filed with the patent office on 2009-05-28 for mattress.
Invention is credited to Manfred Elzenbeck.
Application Number | 20090133195 12/095882 |
Document ID | / |
Family ID | 37770902 |
Filed Date | 2009-05-28 |
United States Patent
Application |
20090133195 |
Kind Code |
A1 |
Elzenbeck; Manfred |
May 28, 2009 |
MATTRESS
Abstract
A description is given of a mattress with at least one elastic
basic body. The basic body has at least one channel in which at
least one resilient rake can be arranged. The resilient rake
includes an elongate, elastic crosspiece which is capable of
torsion. A multiplicity of resilient arms are fastened on the
crosspiece, each being arranged essentially transversely to the
crosspiece.
Inventors: |
Elzenbeck; Manfred;
(Steinheim, DE) |
Correspondence
Address: |
FACTOR & LAKE, LTD
1327 W. WASHINGTON BLVD., SUITE 5G/H
CHICAGO
IL
60607
US
|
Family ID: |
37770902 |
Appl. No.: |
12/095882 |
Filed: |
December 2, 2006 |
PCT Filed: |
December 2, 2006 |
PCT NO: |
PCT/EP06/11577 |
371 Date: |
November 21, 2008 |
Current U.S.
Class: |
5/718 ;
5/719 |
Current CPC
Class: |
A47C 27/16 20130101;
A47C 27/144 20130101; A47C 27/065 20130101; A47C 27/20 20130101;
A47C 27/148 20130101 |
Class at
Publication: |
5/718 ;
5/719 |
International
Class: |
A47C 27/20 20060101
A47C027/20 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 2, 2005 |
DE |
10 2005 057 910.8 |
Claims
1. A mattress comprising at least one resilient basic body, wherein
the basic body comprises at least one channel in which at least one
resilient rake may be arranged, which comprises an elongate,
resilient crosspiece which is capable of torsion and by which a
plurality of resilient arms is carried, which are respectively
arranged with transverse extension components on the
crosspiece.
2. The mattress of claim 1, wherein the resilient arms have the
shape of bent leaf springs.
3. The mattress of claim 1, wherein the resilient arms are inclined
along the crosspiece, alternately firstly towards an upper face and
secondly towards a lower face of the mattress.
4. The mattress of claim 3, wherein the resilient arms inclined
towards the upper face/towards the lower face of the mattress are
bent in the region of their free ends in a convex manner.
5. The mattress of claim 1, wherein the resilient arms are arranged
in pairs mirror symmetrically to a plane containing the
longitudinal axis of the crosspiece or to the longitudinal axis of
the crosspiece.
6. The mattress of claim 1, further comprising a plate element
being aligned substantially parallel to the upper face and/or to
the lower face of the mattress and is fastened to the free ends of
the resilient arms.
7. The mattress of claim 1, wherein the projection is an elongate
plate which is oriented parallel to the upper face and/or to the
lower face of the mattress.
8. The mattress of claim 1, wherein the crosspiece has a
cross-shaped cross section.
9. The mattress of claim 1, wherein the crosspiece has a round or
oval cross section.
10. The mattress of claim 1, wherein the cross section and/or the
cross-sectional surface of the crosspiece varies in the
longitudinal direction.
11. The mattress of claim 1, wherein the cross sections and/or the
cross-sectional surfaces of the resilient arms and/or the material
of which the resilient arms consist, vary along the crosspiece.
12. The mattress of claim 1, wherein the crosspiece and/or the
resilient arms are made of plastic, which is penetrated by natural
fibres reinforcements.
13. The mattress of claim 1, wherein the basic body is made of
foamed material and/or latex.
14. The mattress of claim 1, wherein the channel is open or
openable at least on one side of the mattress.
15. The mattress of claim 1, further comprising a plurality of
resilient rakes with different spring effects being distributed
throughout the basic body.
16. The mattress of claim 1, wherein a plurality of resilient rakes
is arranged within the basic body at various distances from an
upper face of the mattress.
17. The mattress of claim 1, wherein a plurality of resilient rakes
are connected by flexible connecting means to form a flexible
mat.
18. The mattress of claim 17, wherein the connecting means is
formed by wires, flexible strips, or fabrics, that are respectively
at least partially made from plastics, rubber, or a different
elastomer, metal, or compounds thereof.
19. The mattress of claim 18, wherein the wires, strips, or fabrics
are releasably or permanently connected to the resilient rakes.
20. The mattress of claim 1, wherein the first ends of the at least
one resilient rakes are formed by at least one crosspiece portion
bearing an arm and the other ends of the at least one resilient
rake formed by a crosspiece portion not bearing an arm.
21. The mattress of claim 1, wherein at least several adjacent
resilient rakes are connected by flexible connecting means.
22. The mattress of claim 21, wherein the connecting means and the
several adjacent resilient rakes are provided with correspondingly
designed latching means.
23. The mattress of claim 21, wherein flexible connecting means is
configured for a flexible connection of the crosspieces of adjacent
resilient rakes.
24. The mattress of claim 21, wherein at least several of the
connecting means are configured for an inclinable connection of the
crosspieces of adjacent resilient rakes.
25. The mattress of claim 23, wherein connecting means are formed
integrally on the crosspiece of the resilient rake.
26. The mattress of claim 21, wherein the connecting means is are
designed as separate components.
27. The mattress of claim 17, wherein the resilient rakes comprise
receiver means for securing the connecting means.
28. The mattress of claim 27, wherein the receiver means is
mushroom-shaped and configured for positively securing the
connecting means.
29. The mattress of claim 1, wherein the at least one resilient
rake is formed from a plurality of separately designed resilient
rake portions connected to one another.
30. The mattress of claim 29, wherein the at least one resilient
rake portion is configured as a crosspiece portion with at least
one resilient arm formed integrally thereon.
31. The mattress of claim 30, wherein the adjacent crosspiece
portions respectively comprise correspondingly configured plug-in
means or latching means for coupling to a resilient rake.
32. The mattress of claim 29, wherein a resilient rake portion
comprises a resilient arm or a resilient arm sub-assembly, which is
carried by the crosspiece.
33. The mattress of claim 30, wherein a resilient rake is formed by
a plurality of resilient rake portions which have variable lengths
and/or variable numbers of resilient arms and/or variable resilient
arm geometries and/or variable rigidity.
34. The mattress of claim 1, wherein the resilient rakes or the
resilient rake portions are at least partially enclosed by a fibre
material or a film material.
35. The mattress of claim 1, wherein the resilient rakes or the
resilient rake portions are produced at least partially from
fibre-reinforced plastics material that, comprises natural
fibres.
36. The mattress of claim 1, wherein a resilient rake core
comprises a plurality of superimposed resilient rake mats which in
turn are formed by a plurality of resilient rakes.
37. The mattress of claim 36, wherein a separating layer is located
at least between two of the resilient rake mats.
38. The mattress of claim 37, wherein the separating layer has less
friction with the resilient rake mats and/or acts in a
load-distributing manner between the resilient rake mats.
Description
[0001] The invention relates to a mattress comprising at least one
resilient basic body.
[0002] Known mattresses comprise one or more assembled basic bodies
made of foamed material and/or latex. For improving the reclining
comfort it is often desirable to vary the hardness of the mattress
over the length and/or the width thereof, the surfaces of the
mattress being intended to remain pleasantly soft. In known
mattresses made of foamed material and/or latex, to this end
material is locally cut out from or cut into the basic body in
regions, in which the mattress is intended to be less hard, i.e. is
intended to yield more easily to the weight of a user. A
reinforcement in specific regions is, however, not able to be
implemented in this manner. Moreover, once cut out, the regions may
no longer be pushed back into the basic body. The hardness profile
of the mattress, i.e. the hardness of the mattress over its
surface, may not be individually adapted, for example to the size
and/or the weight of a person, subsequently at the place of
use.
[0003] It is the object of the present invention to design a
mattress of the aforementioned type such that the hardness/the
hardness profile of the mattress may be easily altered, in
particular even at the place of use.
[0004] This object is achieved according to the invention in that
the basic body comprises at least one channel, in which at least
one resilient rake may be arranged, which comprises an elongate,
resilient crosspiece which is capable of torsion, to which a
plurality of resilient arms is fastened, which are respectively
arranged substantially transversely to the crosspiece.
[0005] According to the invention, therefore, the basic body which
is soft and resilient per se, may be provided individually with
resilient rakes, via which the local hardness of the mattress may
be adapted according to the weight of a user and according to the
weight distribution. The fundamental idea, in this case, is that
the crosspiece, due to its torsional capability compensates for
point loads which act on the resilient arms. With a point load on
one of the resilient arms a torsional moment is exerted on the
crosspiece and said crosspiece is twisted.
[0006] The resilient arms are arranged so that by twisting a
resilient arm an adjacent resilient arm is tensioned so that it
counteracts the load and hardens the mattress in the region of the
load.
[0007] The resilient rakes may, moreover, be easily removed or
exchanged for a resilient rake with different spring
properties.
[0008] So that a uniform, resilient force transmission may be
implemented between the basic body and the resilient arms, the
resilient arms may be configured in a similar manner to bent leaf
springs.
[0009] In a particularly advantageous embodiment, the resilient
arms may be inclined along the crosspiece, alternately firstly
towards an upper face and secondly towards a lower face of the
mattress. This has the advantage that when loading, for example a
resilient arm extending upwards from the crosspiece, away from the
upper face of the mattress, said resilient arm is pressed in the
direction of the lower face. As a result, a torsional moment acts
on the crosspiece, such that said crosspiece is twisted to such an
extent that the adjacent resilient arms, which are inclined from
the crosspiece towards the lower face of the mattress, are pivoted
upwards. By the upward movement of said resilient arms inclined
from the crosspiece in the direction of the lower face of the
mattress, the height of the resilient rake is reduced with said
resilient arms, so that the effect of the load is distributed over
a larger surface area.
[0010] Moreover, the resilient arms inclined towards the upper
face/towards the lower face of the mattress may be bent back in the
region of their free ends from the upper face/lower face of the
mattress. In this manner, the ends of the resilient arms gently
nestle against the adjacent top layers of the core of the mattress,
generally made from foamed material, substantially tangentially
thereto, so that for this reason a point load is distributed over a
large surface area on the top layer of material.
[0011] In order to obtain a hardness profile which is as uniform as
possible over the surface of the mattress, the resilient arms may
be arranged in pairs mirror symmetrically to a plane containing the
longitudinal axis of the crosspiece or to the longitudinal axis of
the crosspiece. In this manner, not only adjacent but additionally
opposing resilient arms are used for distributing the load.
[0012] Moreover, respectively one plate element, in particular
aligned substantially parallel to the upper face and/or to the
lower face of the mattress, in particular an angular, round or
fork-shaped plate element, may be fastened to the free ends of the
resilient arms. In this manner, the compensating effect of the
resilient rake is markedly increased further.
[0013] The crosspiece may be an elongate plate which is oriented in
particular parallel to the upper face and/or to the lower face of
the mattress. Elongate plates may be easily produced. The resilient
rake may therefore easily be produced, in particular in one piece.
They are also advantageous with regard to their torsional behaviour
which is predeterminable by altering the cross section.
[0014] In order to ensure a high degree of torsional strength of
the crosspiece with a low use of material, and in order to obtain
the effect of the resilient rake distributing the load even over a
larger part of its entire length, the crosspiece may have a
cross-shaped cross section.
[0015] The crosspiece may also comprise a round or oval cross
section (tubular or solid profile) for increasing the torsional
strength of the resilient rake.
[0016] The cross section and/or the cross-sectional surface of the
crosspiece may vary in the longitudinal direction, whereby its
torsional strength and thus the effect of the resilient rake
distributing the load also varies over its length.
[0017] Additionally or instead of which, the cross sections and/or
cross-sectional surfaces of the resilient arms and/or the material
of which the resilient arms consist, may also vary along the
crosspiece.
[0018] The crosspiece and/or the resilient arms may be made of
plastics which in particular contains reinforcing fibres,
preferably natural fibres. In this manner, they may be easily
produced, in particular injection-moulded or cast. The stability is
increased, in particular, by the filling material.
[0019] The basic body may be made from foamed material and/or
latex. Basic bodies made of foamed material or latex may be
produced easily and treated. Moreover, said materials are
permanently elastic.
[0020] So that the resilient rakes may be easily inserted into a
channel and/or withdrawn from such a channel, the channels may be
open or openable at least on one side of the mattress. In this
manner, the hardness and/or the hardness profile of the mattress
may also be adapted easily at the place of use by inserting,
removing or replacing resilient rakes according to the requirements
of the user.
[0021] In order to allow optimal adaptation of the hardness profile
of the mattress to the body of a user, in the basic body a
plurality of resilient rakes with different spring effects, in
particular different hardnesses and/or distribution of hardness may
be distributed over the length of the mattress. In this manner, in
particular in the back and lumbar region a different mattress
hardness may be predetermined from that in the head or leg region.
Also such a variation in the hardness of the mattress may be
predetermined towards the edges thereof.
[0022] Moreover, in the basic body a plurality of resilient rakes
may be arranged at various distances from an upper face of the
mattress. In this manner, the hardness profile of the mattress may
also be adapted over the depth of the mattress.
[0023] Adjacent resilient rakes may be connected by flexible or
bendable connecting means, which connect the resilient rakes to
form a mat which may be handled substantially in one piece and
which is resilient perpendicular to its plane. The connecting means
are preferably produced from the same material as the resilient
rakes and are designed geometrically such that they have at least
in folded regions of the mat less rigidity than the crosspieces
and/or resilient arms of the resilient rakes. In other regions,
they may be designed such that adjacent resilient rakes are
maintained at a uniform distance.
[0024] In a preferred embodiment, the connecting means of the mat
have moments of resistance against flexion and/or torsion which is
at most 75%, preferably at most 50%, particularly preferably at
most 25% of a moment of resistance against bending and/or torsion
which the crosspieces or resilient arms of the resilient rakes
comprise.
[0025] In order to allow a simple assembly of the adjacent
resilient rakes to form a mat made of resilient rakes, the
connecting means and the resilient rakes are provided with
correspondingly designed latching means. The latching means are
adapted to one another such that preferably a toolless assembly may
be undertaken, but the resilient rakes may nevertheless be reliably
latched to one another. In this case, it may be provided that at
least several of the connecting means ensure a substantially
uniform spacing of adjacent resilient rakes. A relative mobility of
the angle of adjacent resilient rakes results in this case from the
flexibility of the connecting means and/or the crosspieces of the
resilient rakes.
[0026] In a further embodiment of the invention, connecting means
are configured for an articulated, in particular pivotably movable,
connection of the crosspieces of adjacent resilient rakes. This
allows relative movements between the resilient rakes connected to
the corresponding connecting means, without in this case
considerable elastic deformations of the resilient rakes and/or the
connecting means occurring. Such an articulated, in particular
pivotably movable, connection of the resilient rakes is
advantageous with a use of the mattress in connection with an
adjustable, in particular motor driven, bed frame and/or slats, as
folded points in the mattress defined therefor are advantageous.
The connecting means are, in this case, configured such that a
pivoting movement of adjacent resilient rakes may take place about
a pivot axis, which is aligned at least substantially parallel to
the crosspieces of the adjacent resilient rakes.
[0027] In one of the preferred embodiments of the invention,
connecting means are formed integrally on the crosspiece of the
resilient rake. This permits a simple production of the connecting
means in a plastics injection-moulding method and ensures a
reliable connection to the corresponding crosspiece of the
resilient rake. In another of the preferred embodiments of the
invention, it may be provided that adjacent resilient rakes are
connected both by connecting means formed integrally on the
crosspieces of the resilient rakes and also by additional, engaged
connecting means. In this case, the integrally formed connecting
means produce basic stability of the mat, whilst the additionally
engaged, separately configured, connecting means may be used for
local reinforcement of the mat. To this end, the connecting means
may be provided as separate components.
[0028] In a further embodiment of the invention the resilient rakes
may be provided with receiver means for securing the flexible
connecting means. This permits a rapid and cost-effective
attachment of the flexible connecting means to the resilient rakes.
In this case, the receiver means may be designed, in particular,
for an at least partially non-positive securing of the flexible
connecting means. In one embodiment of the invention, slots of
substantially V-shaped design are provided on the resilient rakes
into which the flexible connecting means, in particular wires,
flexible strips or fabric strips, may be pushed in for securing to
the resilient rake and secured non-positively by mutual elastic or
possibly also plastic deformation.
[0029] In a further embodiment of the invention it is provided that
the receiver means are configured at least partially for positively
securing the flexible connecting means. To this end, the receiver
means which are attached to the resilient rakes, and/or the
flexible connecting means are provided with undercut geometries in
order to create the desired positive connection.
[0030] In a preferred embodiment of the invention, the receiver
means are attached as substantially dimensionally stable
mushroom-shaped pins to the resilient rakes and the connecting
means are of strip-shaped design. In this case, through-passages
are provided in the connecting means, which make it possible to
push onto the receiver means for the positive securing.
[0031] In a further embodiment of the invention it is provided that
at least one resilient rake is formed from a plurality of
separately designed resilient rake portions connected to one
another. This allows a modular construction of the resilient rake
and/or of a mat constructed from a plurality of resilient rakes.
The resilient rake portions may have an integral or variable
design. A variable design may refer both to the geometry and to the
choice of material for the respective resilient rake portion. By
combining differently designed resilient rake portions, the
resilient rakes may be individually adapted to the requirements of
various reclining zones of the mattress. For example, it is
possible to achieve over the width of the mattress, by a suitable
combination and selection of resilient rake portions, a variable
mattress hardness, by inserting, for example in regions of the
mattress in the vicinity of the edge, resilient rake portions
designed to be harder whilst in central regions of the mattress
softer resilient rake portions may be used.
[0032] In a preferred embodiment of the invention, the resilient
rake portion is configured as a crosspiece portion with at least
one resilient arm formed integrally thereon. This allows a simple
assembly of resilient rake portions to form a resilient rake. The
resilient arms are already formed integrally during the production
of the resilient rake portions in a plastics injection-moulding
method and thus in a robust manner.
[0033] Preferably, adjacent crosspiece portions respectively have
correspondingly configured plug-in means or latching means for
coupling to a resilient rake. As a result, a preferably toolless
coupling of the resilient rake portions may be achieved, so that
the resilient rakes may be plugged together in the manner of a
plug-in module from the modular resilient rake portions.
[0034] In an alternative embodiment of the invention, the resilient
rake portions are designed as a resilient arm or as a resilient arm
sub-assembly, which is designed for attaching to a crosspiece. In
this embodiment, it is provided that a crosspiece for forming a
resilient rake may be provided with the resilient arms or resilient
arm sub-assemblies. Preferably, the crosspiece is provided with
latching means in a uniform or variable distribution. With the use
of individual resilient arms, in specific regions of the resilient
rake a greater resilient arm density may be achieved, be achieved,
whilst other regions of the resilient rake are produced with a
lower resilient arm density. Resilient arm sub-assemblies which
comprise two or more resilient arms have is the advantage relative
to individual resilient arms that they allow a preferably
symmetrical support relative to forces which are introduced and
thus are more advantageously loaded. In a preferred embodiment of
the invention, a resilient arm sub-assembly comprises four
approximately cross-shaped resilient arms projecting from a central
node, the central node being configured for positioning on the
crosspiece.
[0035] Advantageously, a resilient rake may be formed by a
plurality of resilient rake portions which have variable lengths
and/or variable numbers of resilient arms and/or variable resilient
arm geometries and/or variable rigidity. This allows an individual
adaptation of the respective resilient rakes to the corresponding
region of the mattress, in which the resilient rake is intended to
be used. As the requirements with regard to the hardness and/or
flexibility of the mattress alter both over the longitudinal
direction thereof and also over the transverse direction thereof, a
partial adaptation to these various requirements may be achieved
with the resilient rakes according to the invention.
[0036] Preferably the resilient rakes or resilient rake portions
are at least partially enclosed by a fibre material or a film
material. The object of the fibre material and/or film material is,
when using the mattress, to create possible relative movements
between adjacent resilient arms, with low friction, so that only
minimal noise is generated when altering the loading of the
mattress.
[0037] By superimposing a plurality of resilient rake mats, it is
possible to increase the spring lift when the loading of the
individual resilient arms of the resilient rakes is unaltered. Also
the flexibility of the mattress is improved compared to a mattress
with an individual resilient rake layer with a plurality of
heights.
[0038] A separating layer between adjacent resilient rake mats
allows, on the one hand, a distribution of the force between the
mats and simplifies, on the other hand, small displacements on the
adjacent surfaces of the resilient rake mats.
[0039] Several embodiments of the invention are described
hereinafter with reference to the drawings, in which:
[0040] FIG. 1 shows schematically in horizontal section, in
vertical section and in side view a first embodiment of a mattress
with two basic bodies, between which in the longitudinal direction
a plurality of resilient rakes is arranged;
[0041] FIG. 2 shows an enlarged side view of a part of the mattress
of FIG. 1 in detail;
[0042] FIG. 3 shows a front view of one of the resilient rakes of
FIG. 1 viewed in the transverse direction of the mattress;
[0043] FIG. 4 shows a side view of the resilient rake of FIG. 3
viewed in the longitudinal direction of the mattress;
[0044] FIG. 5 shows a plan view of the resilient rake of FIG.
3;
[0045] FIG. 6 shows the resilient rake of FIG. 3 in an isometric
view;
[0046] FIG. 7 shows schematically a vertical section of a second
embodiment of a mattress comprising three basic bodies, between
which resilient rakes are arranged alternately in two planes;
[0047] FIG. 8 shows a resilient rake of a third embodiment of a
mattress in isometric view, in this case a plurality of resilient
arms being arranged in pairs symmetrically to a vertical plane of
symmetry;
[0048] FIG. 9 shows a resilient rake of a fourth embodiment of a
mattress in isometric view, in which round plates are attached to
the free ends of the resilient arms;
[0049] FIG. 10 shows a resilient rake of a fifth embodiment of a
mattress in isometric view, in which rectangular plates are
attached to the free ends of the resilient arms;
[0050] FIG. 11 shows a resilient rake of a sixth embodiment of a
mattress in isometric view, in which fork-shaped plates are
attached to the free ends of the resilient arms;
[0051] FIG. 12 shows a resilient rake of a seventh embodiment of a
mattress in isometric view, the crosspiece thereof having round
torsion portions located between the resilient arms of reduced
cross section;
[0052] FIG. 13 shows a resilient rake of an eighth embodiment of a
mattress in isometric view, the crosspiece thereof having a
cross-shaped cross section;
[0053] FIG. 14 shows an isometric view of a resilient rake mat made
up of resilient rakes;
[0054] FIG. 15 shows a partially fragmented view of a mattress
which has been obtained by uncovering a spring core mat according
to FIG. 15 comprising foamed material;
[0055] FIG. 16 shows a similar view to FIG. 15 in which a further
modified mattress is shown;
[0056] FIG. 17 shows a resilient rake portion with individually
attached resilient arms, in a perspective front view;
[0057] FIG. 18 shows the resilient rake portion according to FIG.
17 in a perspective view from behind;
[0058] FIG. 19 shows a crosspiece portion with receiver means for
flexible connecting means;
[0059] FIG. 20 shows a resilient rake portion with individually
attached connecting means;
[0060] FIG. 21 shows a resilient arm sub-assembly for attaching to
a crosspiece;
[0061] FIG. 22 shows a crosspiece portion and a separately designed
connecting means;
[0062] FIG. 23 shows a similar view to FIG. 22 in which a modified
embodiment is shown,
[0063] FIG. 24 shows a view of a resilient rake mat, which has been
obtained by joining together a plurality of parallel resilient
rakes, which have been held together by longitudinal connecting
means extending perpendicular to the resilient rake axes, a lower
left part being shown as a double mat variant,
[0064] FIG. 25 shows an enlarged view of a resilient rake segment
of the mat of FIG. 24 in enlarged scale,
[0065] FIG. 26 shows a view of the resilient rake segment of FIG.
25, in this case from the right,
[0066] FIG. 27 shows a section through the resilient rake segment
of FIG. 25 along the cutting line XXVII-XXVII at that point,
and
[0067] FIG. 28 shows a transverse section through a mattress with a
resilient rake core comprising two superimposed resilient rake
mats.
[0068] FIG. 1 shows positioned side-by-side in a conventional
manner a plan view, a side view and a front view of a mattress.
More specifically, it is only the mattress core which is provided,
to be completed further by wool layers, horsehair layers or other
layers which are desired with regard to the upholstery and
controlling the temperature of the reclining surface. This unit is
then further provided with a cover.
[0069] In FIG. 1, top right, a mattress provided as a whole with
the reference numeral 1 is shown in horizontal section along an
abutting surface between two superimposed flat, elongate, cuboid
basic bodies 3 and 5 connected to one another. The mattress 1 may
additionally be accommodated in a preferably openable cover, not
shown.
[0070] The basic bodies 3 and 5 are made of resilient foamed
material. They comprise, as is visible in the side view in FIG. 1,
top left, and in the detail in FIG. 2, respectively in their side
22 facing the respective other basic body 5 and/or 3, straight,
parallel channel halves 7 of transverse channels 9 which are
provided equidistant in the longitudinal direction of the mattress
1 at a distance of approximately 7 cm in the transverse direction
thereof.
[0071] The upper end (head end) in FIG. 1 and the lower end (foot
end) of the mattress 1 which respectively make up approximately a
tenth of the mattress length, are free from channels 9. The basic
bodies 3 and 5 are fastened to one another here.
[0072] The channels 9 are continuously open over the entire width
of the mattress 1 transversely and open on both longitudinal sides
11 of the mattress 1, of which one channel is shown top left in
FIG. 1. This is also visible in the vertical section of the
mattress 1 at the bottom in FIG. 1.
[0073] All channels 9 have the same six-cornered profile and are
symmetrically accommodated in halves respectively in one of the
basic bodies 3 and 5. The channel halves 7 are in contact with two
opposing common edges of the six-cornered channels 9.
[0074] The respectively adjacent channel halves 7 in the basic
bodies 3 and 5 are separated by partitions 13 which are
approximately trapezoidal in profile. The front faces of the
respectively opposing partitions 13 when the basic bodies 3 and 5
are superimposed, rest against one another in a separable
manner.
[0075] The channels 9 visible in FIG. 1 in horizontal section in
the upper quarter of the mattress 1 are provided for adapting the
hardness of the mattress 1 in the head region, those in the centre
region of the mattress 1 are provided for adapting the hardness in
the back region and those in the lower quarter are provided for
adapting the hardness in the foot region of a user.
[0076] In the two upper channels 9 of the head region, in the
central five channels 9 of the back region and in the two lower
channels 9 of the foot region, in the longitudinal direction of the
channels 9 two respective resilient rakes 15 are arranged in
succession. The resilient rakes 15 extend respectively
approximately from the centre to the corresponding longitudinal
side of the mattress 1. The resilient rakes 15 of the head region,
of the back region and of the foot region have different effects on
the hardness of the mattress 1 in the respective region.
[0077] The resilient rakes 15 respectively have a flat crosspiece
17 which is elongate, resilient and torsionally capable and which
is plate-shaped in the transverse direction of the mattress 1. The
crosspiece 17 is oriented parallel to the upper face of the upper
basic body 3 and to the lower face of the basic body 5.
[0078] On the two longitudinal edges of the crosspiece 17 a
plurality of resilient arms 19 are formed in the form of bent leaf
springs. The resilient arms 19 extend respectively substantially
transversely to the crosspiece 17, i.e. in the longitudinal
direction of the mattress 1. They are arranged in pairs mirror
symmetrically to a plane containing the longitudinal axis of the
crosspiece 17 and extending perpendicular to said crosspiece.
[0079] The crosspiece 17 and the resilient arms 19 are produced
from a plastics material which is filled with natural fibres.
[0080] Successive resilient arms 19 of the crosspiece 17 extend
alternately respectively by approximately 45.degree. from the
horizontal plane of the crosspiece 17 in opposing directions away
from the crosspiece 17, in FIG. 6 firstly upwards and secondly
downwards. In the position of use they extend, therefore, firstly
towards the upper face and secondly towards the lower face of the
mattress 1.
[0081] The upwardly pointing resilient arms 19 are, in the region
of their free ends, bent downwards in a convex manner. The
resilient arms 19 angled downwards are accordingly bent upwards in
a convex manner away from the lower face of the mattress 1.
[0082] The resilient rakes 15 of the head region, the back region
and the foot region may vary in cross sections and/or materials, so
that they have different spring effects and thus variable influence
on the longitudinal hardness and distribution of hardness over the
length of the mattress 1.
[0083] The resilient arms 19 may have a variable spring effect over
the length of the crosspiece 17, so that the transverse hardness
varies in the transverse direction of the mattress 1 towards the
longitudinal sides thereof.
[0084] For inserting into the mattress 1, the resilient rakes 15
are pushed in from one longitudinal side 11 of the mattress 1 into
the channels, such that the opposing resilient arms 19 are
respectively received in one of two adjacent channels 9, the
crosspiece 17 being pushed through between the front faces of the
corresponding partitions 13. The resilient rakes 15 are
respectively pushed forward approximately as far as the centre of
the mattress 1.
[0085] Into each channel pair to be equipped with resilient rakes
15, a resilient rake 15 is pushed from each longitudinal side 11 of
the mattress 1.
[0086] According to requirements, different channels 9 may be
equipped with different resilient rakes 15. For example, for large
people the number of equipped channels 9 in the back region may be
increased. For heavy people, resilient rakes 15 may be used with an
increased hardness effect.
[0087] For removing or replacing one of the resilient rakes 15 for
another, in particular with a different hardness effect, said
resilient rake is simply pulled out of the corresponding adjacent
channels 9.
[0088] In FIG. 7 a vertical section of a second embodiment of a
mattress 101 is shown in the region of channels 109, 109'. In
contrast to the first embodiment disclosed in connection with FIGS.
1 to 6, in this case instead of two basic bodies, three basic
bodies 103, 105 and 106 are layered on top of one another.
[0089] The resilient rakes 15 are laterally offset from one another
firstly in the channels 109 between the upper basic body 103 and
the central basic body 105 and secondly in the channels 109'
arranged between the central basic body 105 and the lower basic
body 106.
[0090] In FIG. 8 a resilient rake 315 is shown of a third
embodiment of a mattress which is similar to the mattresses 1; 101,
but otherwise not shown. In contrast to the first embodiment
described in connection with FIGS. 1 to 6, in this case resilient
arms 319 are arranged in pairs mirror symmetrically to a plane
containing the axis of a crosspiece 317 which extends perpendicular
to the surface of the crosspiece 317. The resilient arms 319 are
inclined in pairs in the longitudinal direction of the crosspiece
317 alternately in FIG. 8 firstly upwards i.e. towards the upper
face of the mattress, and secondly downwards, i.e. towards the
lower face of the mattress.
[0091] In a resilient rake 415 shown in FIG. 9 of a fourth
embodiment of a mattress which is similar to the mattresses 1; 101,
but otherwise not shown, in contrast to the first embodiment
described in connection with FIGS. 1 to 6 respectively a round
plate element 470 is fastened to the free ends of the resilient
arms 419.
[0092] The plate elements 470 are aligned in the load-free state
substantially parallel to the crosspiece 17, i.e. also aligned with
the upper face and the lower face of the mattress. To represent all
resilient arms 419 of the resilient rake 415, in FIG. 9 merely the
left pair of spring arms 419 is shown with the plate elements
470.
[0093] The plate elements 470 are formed with their edge on the
respective front face edge of the resilient arms 419. The contours
of the resilient arms 419 merge in the fastening region with the
corresponding contours of the plate elements 470.
[0094] A resilient rake 515 of a fifth embodiment of a mattress
which is similar to the mattresses 1; 101, but otherwise not shown,
is shown in FIG. 10. In contrast to the fourth embodiment described
in connection with FIG. 9, the free ends of the resilient arms 519
in this case respectively have a rectangular plate element 570
instead of the round plate elements 470. This is also merely shown
on the left resilient arm pair which is representative in FIG. 10
for all resilient arms 519.
[0095] In FIG. 11 a resilient rake 615 is shown of a sixth
embodiment of a mattress which is similar to the mattresses 1; 101,
but otherwise not shown. In this case, the free ends of the
resilient arms 619 respectively comprise instead of the round
and/or rectangular plate element 470 and/or 570 a fork-shaped plate
element 670. Also in this case, only the plate elements 670 of the
left resilient arm pair are shown as being representative of all
others.
[0096] In FIG. 12 a resilient rake 715 is shown of a seventh
embodiment of a mattress which is similar to the mattresses 1; 101,
but otherwise not shown, in which a crosspiece 717 does not have a
flat, plate-shaped profile but a round profile. The diameter of the
crosspiece 717 is respectively reduced between adjacent pairs of
resilient arms 19. In this case it has reduced torsional strength.
Thus local loading is less evenly distributed.
[0097] In FIG. 13 a resilient rake 815 is shown of an eighth
embodiment of a mattress which is similar to the mattresses 1; 101,
but otherwise not shown. In this case, the crosspiece 817 has a
rectangular cross-shaped cross section of which a first flat plate
818 forming the cross in cross section, extends parallel to the
lower face and to the upper face of the mattress.
[0098] The resilient arms 19 inclined upwards in FIG. 13, i.e.
towards the upper face of the mattress, are fastened to the side
edges of the first plate 818. The resilient arms 19 inclined
downwards, i.e. towards the lower face, are fastened on both sides
of the first plate 818 to the side edges of the second flat plate
820.
[0099] Such a crosspiece has a greater torsional strength than a
plate-shaped crosspiece, so that point loads are further
distributed.
[0100] It is understood that the different cross-sectional shapes
of the crosspiece discussed above also may be provided in different
axial portions of a crosspiece, in order to vary the torsional
strength of the crosspiece in the transverse direction of the
mattress.
[0101] Instead of two and/or three superimposed basic bodies 3 and
5 and/or 103, 105 and 106, the mattress 1; 101 may also have only
one basic body or more than three basic bodies. The basic bodies
may be arranged behind one another or adjacent to one another
instead of one above the another, even in the longitudinal
direction and/or in the transverse direction of the mattress.
[0102] The basic bodies 3, 5; 103, 105, 106 may also be made from a
different resilient material, for example from latex or a
combination of latex and foamed material, instead of foamed
material.
[0103] The basic bodies may also have only one channel and/or
channel pair 9; 109, 109'. The channels 9; 109, 109' may extend
longitudinally or obliquely to the mattress 1; 101 or towards one
another instead of transversely.
[0104] The channels 9; 109, 109' may also be spaced apart from one
another at greater or smaller distances than 7 cm and also at
different distances. More or fewer than 22 channels 9; 109, 109'
may be provided.
[0105] They may also be open on a longitudinal or transverse side
of the mattress 1; 101. They may be closed on both sides. In this
case, they may be made accessible by separating the basic bodies 3
and 5 and/or 103, 105 and 106 from one another, or resilient rakes
may be used which extend over the entire width of the basic
bodies.
[0106] In the channels 9; 109, 109' provided with resilient rakes
15; 315, 415, 515, 615, 715, 815 respectively only one resilient
rake 15; 315, 415, 515, 615, 715, 815 may also be arranged. The
resilient rake 15; 315, 415, 515, 615, 715, 815 may also extend
over the entire width of the mattress 1; 101. More than two
correspondingly shorter resilient rakes may also be accommodated in
one channel 9; 109, 109'.
[0107] The crosspiece 17; 717; 817 and/or the resilient arms 19;
319; 419; 519; 619 may also consist of plastics with other filling
materials instead of plastics with natural fibres. They may also be
made of a different elastic, resilient and/or torsionally capable
material, for example spring steel plate. The crosspiece 17; 717;
817 and the resilient arms 19; 319; 419; 519; 619 may also be made
from different materials. The crosspiece 17; 717; 817 and resilient
arms 19; 319; 419; 519; 619 may also be able to be made up of
multiple parts, or even replaced in a modular manner. The material
of the crosspiece 17; 717; 817 and/or the resilient arms 19; 319;
419; 519; 619 may also vary along the crosspiece 17; 717; 817.
[0108] Also, the cross section and/or the cross-sectional surface
of the resilient arms 19; 319; 419; 519; 619 may vary along the
crosspiece 17; 717; 817.
[0109] Apart from in the round crosspiece 717 of the seventh
embodiment disclosed in connection with FIG. 12, in all other
embodiments the cross section and/or the cross-sectional surface of
the crosspiece 17; 817 may also vary in the longitudinal direction.
For example, there may also be a continuous reduction of the
cross-sectional surface over the length. The round crosspiece 717
in the seventh embodiment of FIG. 12 may also have a uniform cross
section over its length. It may also have an oval profile instead
of a round profile.
[0110] Instead of the angular, round or fork-shaped plate elements
470; 570; 670, differently shaped plate elements may also be
arranged on the free ends of the resilient arms 519; 619; 719.
Additionally, different plate shapes may be formed on a common
crosspiece 17; 717; 817. It is also possible for only individual
resilient arms 519; 619; 719 of a crosspiece 17; 717; 817 to be
provided with plate elements 470; 570; 670.
[0111] In FIGS. 14 and 15 a resilient rake mat denoted as a whole
by 910 is shown, which is constructed from a plurality of
successive resilient rakes 915, as has been disclosed above. The
individual resilient rakes of successive rows are respectively
distributed offset by half a length relative to one another as is
clearly visible from FIG. 14.
[0112] The resilient rakes 915 are connected by four wires 980,
982, 984, 986 extending in the longitudinal direction to form a
flexible mat. The securing of the wires 980 to 986 to the
individual resilient rakes 915 may take place by different types of
mechanical connection, for example by clipping into indentations of
the resilient rakes, bonding, welding (wires made of plastics
material), knotting, mechanical clamping connections and the
like.
[0113] Instead of wires, flexible strips or fabrics may also be
used for connecting the resilient rakes, said strips or fabrics, as
are the aforementioned wires, being able to consist of plastics,
rubber or a different elastomer, metal or fibre material (cord,
rope).
[0114] The resilient rake mat 910 may be used, together with two
flat top layers 990, 992 made of foamed material as well as with
frame parts 994 also made of foamed material, to form a mattress
core 996 as shown in FIG. 16. In this case, the different parts
made of foamed material are bonded or welded together so that the
resilient rake mat 910 is held unreleasably in the inside of the
mattress core 996.
[0115] If desired, the respective surface of the top layers 990,
992 facing the resilient rake mat 910 may be shaped, such that the
resilient arms are received entirely or at least with their free
ends positively in the inner faces of the top layers 990, 992.
[0116] In the mattress according to FIG. 16 the resilient rake mat
910 is shorter. It extends only over approximately 4/5 of the
length of the mattress. In the mattress portion at the head end, a
further resilient rake mat 9101 is arranged which, in principle,
has the same construction as the resilient rake mat 910; only its
resilient rakes 515' are shorter and aligned in the longitudinal
direction of the mattress. Two wires 980' and 986' are sufficient
to connect the resilient rakes 915'.
[0117] In this manner, the horizontal and longitudinal hardness
profiles of the mattress in the regions of the resilient rake mats
910 and 910' may be predetermined to be variable.
[0118] In order to provide the resilient rake mats or an adjacent
arrangement of resilient rakes unconnected to one another, with a
substantially smooth edge contour, the resilient rakes as shown in
FIG. 16 for the resilient rakes 915', may be configured such that
one end of the resilient rake is formed by a crosspiece portion
bearing one or two arms, whilst the other end of the resilient rake
is formed by a crosspiece not bearing an arm. The resilient rakes
of adjacent rows are thus respectively rotated by 180 degrees about
a transverse axis relative to one another so that their ends are
respectively transposed.
[0119] In a further modification of the invention, a spring mat may
also be produced from individual resilient rakes by the resilient
rakes being connected to one another by rubber bands instead of
wires.
[0120] As already set out above, the resilient rakes may be
configured such that they do not have the same spring behaviour at
all points. In particular it is possible to configure the resilient
arms which are adjacent to the ends of the resilient rakes, to be
slightly harder so that a harder sitting edge is obtained at the
longitudinal edges of the mattress.
[0121] A further possibility for influencing the hardness of the
mattress is that the resilient rakes are only provided in specific
regions of the mattress, whilst other mattress regions remain free
from resilient rakes, so that at that point the bending properties
result from the degree of hardness and the geometry of the plastics
materials used.
[0122] In the aforementioned embodiments, the resilient rakes
extended in the mattress respectively in the transverse direction.
It is understood that for particular applications resilient rakes
may also be used which are aligned in the longitudinal direction of
the mattress.
[0123] Finally, the resilient rakes may also be oriented
differently in different regions of the mattress, for example
longitudinally in the head region, transversely in the back and hip
region and again longitudinally in the foot region. This allows a
further possibility for designing the local spring behaviour of the
mattress.
[0124] The invention is not restricted to mattresses 1; 101, in
which the upper and lower face extend in parallel. Instead they may
also be used with differently shaped, for example wedge-shaped,
mattresses.
[0125] In the embodiments of the invention shown in FIGS. 17 to 22
it is provided that a resilient rake is constructed from a
plurality of resilient rake portions, which may be produced in
different embodiments and are described hereinafter in more detail.
The resilient rake portions shown may also be combined with one
another.
[0126] In the embodiment according to FIGS. 17 and 18, the
resilient rake portions are designed as prismatic crosspiece
portions 1017, to which respectively two resilient arms 1019 are
associated, projecting symmetrically in opposing directions
obliquely downwards and/or upwards. The resilient arms 1019 are of
strip-shaped design and at the end designed to be bent into the
horizontal, but may easily comprise any other of the aforementioned
geometries for resilient arms.
[0127] At a front face of the crosspiece portion 1017 shown in FIG.
17 a recess 1061 is configured which has a substantially
rectangular cross section. At least one inner face the recess 1061
is provided with a spherical segment-shaped recess 1063 as is shown
in more detail in FIG. 18, the crosspiece portion 1017 has a
plug-in peg 1065 attached to a second front face which is adapted
to the cross section of the recess 1061 and which has a convex
projecting spherical segment-shaped latching lug 1067. The plug-in
peg 1065 of a first crosspiece portion 1017 may be inserted into
the recess 1065 of a second crosspiece portion 1017 and may be
reliably secured and/or latched there by the positive operative
connection between the convex latching lug 1067 and the recess
1063.
[0128] A mushroom-shaped pin 1069 is attached integrally to an
upper face of the crosspiece portion 1017, which is provided for
receiving a flexible perforated strip 1071 which is provided as a
flexible connecting means for coupling a plurality of adjacently
arranged resilient rakes.
[0129] The crosspiece portion 1117 shown in FIG. 19 is provided for
coupling two crosspiece portions 1017 provided with resilient arms,
as are shown in FIGS. 17 and 18. The crosspiece portion 1117 has at
an upper face two integrally attached receiver means 1173. These
receiver means 1173 are provided with a substantially V-shaped
recess 1175, which merges in an end region with a circular
cylindrical recess and thus has a key hole-like cross section. The
recess 1175 is provided for receiving flexible connecting means in
a frictional connection, in particular wires or resilient cords.
The connecting means are shown by way of example as a rubber band
and are pushed into the V-shaped recess 1175 and held in the
circular cylindrical region of the recess 1175. As a result, a
mutual elastic deformation of the receiver means 1173 and the
connecting means 1175 occurs which leads to a reliable securing of
the crosspiece portion 1117 on the connecting means 1175.
[0130] The crosspiece portion 1217 shown in FIG. 20 has in contrast
to the crosspiece portions 1017 shown in FIGS. 17 and 18 an
integrally formed fastening clamp 1279. The fastening clamp 1279 is
provided with latching lugs 1281 which are configured for engaging
in latching recesses 1283. By the integrally formed fastening clamp
1279, a stable latching connection between adjacent crosspiece
portions 1217 may be produced which is particularly easy to
assemble. The crosspiece portion 1217 shown in FIG. 20 may both be
connected at its front face which is located at the front and also
at the rear to further crosspiece portions, not shown. In this
case, it may also be provided that crosspiece portions as have been
proposed in FIGS. 17 to 19 and/or in FIG. 22, subsequently
described in more detail, are connected to the crosspiece portion
1217 shown.
[0131] In the embodiment of the invention shown in FIG. 21, it is
provided that a continuous crosspiece 1317 is provided with a
plurality of latching recesses 1385. The latching recesses 1385 are
uniformly distributed on the upper and lower face of the crosspiece
1317. Resilient arm sub-assemblies 1383 may be pushed onto the
crosspiece 1317, which are provided with resilient arms 1319
projecting from a cavity 1387 of substantially rectangular cross
section and respectively in opposing directions. On an inner face
of the cavity 1387 convex latching lugs 1367 are configured which
are provided for positive latching to the latching recesses 1385 of
the crosspiece 1317.
[0132] The embodiment of a resilient rake portion shown in FIG. 22
is a modification of the resilient rake portion shown in FIG. 20.
The resilient rake portion according to FIG. 22 is configured as a
crosspiece portion 1417, which respectively may be connected at the
end side to crosspiece portions, not shown, and formed in a similar
manner. On an upper face as well as a lower face, the crosspiece
portion 1417 is respectively provided with latching recesses 1485,
which are provided for a positive latching connection with a
connecting clamp 1479. The connecting clamp 1479 is formed as a
separately designed connecting means and allows a flexible or
bendable connection of adjacent spring portions and/or crosspiece
portions 1417.
[0133] The embodiment shown in FIG. 23 is a modification of the
design according to FIG. 22 with the difference that the crosspiece
portion 1517 is configured at least partially cylindrically. The
connecting clamp 1579 provided for clipping to the cylinder portion
1591 is, with regard to its latching geometry 1593, adapted to this
cylindrical shape of the crosspiece portion 1517. As a result a
pivotably movable connection between the connecting clamp 1579 and
the crosspiece portion 1517 may be effected. This is advantageous
for the use of corresponding resilient rakes in the regions of the
mattress which are intended to be bent.
[0134] A further possibility for the connection between adjacent
resilient rakes allowing pivoting are weakened points in the
connecting means, which for example may be configured in the manner
of film hinges.
[0135] The connecting means shown above for connecting resilient
rake portions may also be used in the same manner for resilient
rakes designed in one piece. This applies both to the integrally
formed connecting means and also to the separately formed
connecting means. Also, a combination of resilient rakes assembled
in an integral and modular manner is conceivable.
[0136] The resilient rakes or the resilient rake portions are at
least partially, preferably entirely, produced from
fibre-reinforced plastics material, which preferably comprises
natural fibres.
[0137] FIG. 24 shows a resilient rake mat denoted as a whole by
2000 which is constructed from resilient rakes 2002 spaced apart
uniformly in the longitudinal direction of the mat. These may again
be injection-moulded in one piece or consist of adjacent segments
in the longitudinal direction of the rake, as shown with reference
to FIGS. 4ff. and 17 to 23 described above and shown at 2004, 2006.
The resilient rakes or the resilient rake segments may be
injection-moulded from preferably fibre-reinforced plastics of
suitable elasticity and suitable breaking strength.
[0138] The resilient rake portions 2004, 2006 have respectively two
pairs of aligned, injection-moulded connecting webs 2008, 2010,
extending perpendicular to the longitudinal direction of the rake
segment (i.e. in the longitudinal direction of the resilient rake
mat 2000), which respectively bear complementary longitudinal
connecting parts 2012, 2014 (see FIG. 25) which form in pairs
respectively one resilient rake connection 216.
[0139] Moreover, the resilient rake portions 2004, 2006 have
extending in their longitudinal direction (i.e. in the transverse
direction of the resilient rake mat 2000) connecting webs 2018,
2020 which bear complementary transverse connecting parts 2022,
2024, which together may form in pairs respectively a transverse
segment connection 2026.
[0140] The connecting parts 20012 and 2014 are slightly offset in
an opposing manner from the plane of the connecting webs 2008,
2010, as is visible from FIGS. 25 and 26. The same applies to the
connecting parts 2022 and 2024 as visible from FIG. 25.
[0141] In detail the connecting points 2016 and 2026 as well as
their connecting parts 2012, 2022 and 2014 and 2024 are of
substantially the same construction and again form releasable
latching connections. The bushes of similar connecting parts 2012
and 2022 have respective lateral walls 2028, 2030 with upper
retaining flanges 2032 and 2034 extending back inside. The walls
2028 and 2030 at their lower ends are connected by a bottom wall
2036 located therebetween. Thus an upwardly open C-rail is obtained
into which the plugs of similar connecting parts 2014 and 2024 may
be inserted. In a region weakened by lateral indentations 2036,
which is located between the retaining flanges 2032 and 2034, the
bottom walls 2036 bear short cylindrical latching pins 2038, which
cooperate with suitable latching blind bores 2040 of the connecting
parts 2014 and/or 2024. In this case, in the connecting parts 2014
in the observed embodiment, three equidistant blind bores 2040 are
provided in order to be able to select the spacing of adjacent
resilient rakes to be variable, whilst for the connecting parts
2024 only one blind bore 2040 is provided.
[0142] The resilient rake portions 2004, 2006 have respectively a
horizontal main crosspiece 2042, in unloaded conditions of use,
which via arcuate resilient arms 2044, 2046 extending alternately
upwards and/or downwards bear shell-shaped bearing parts 2048
and/or 2050. These respectively have outwardly a slightly convex
contact wall 2052 and/or 2054, at the edge thereof a lower
peripheral wall 2056 and/or 2058 extending. In the unloaded state
of a resilient rake, the bearing parts are inclined by
approximately +20 degrees and/or -20 degrees to the horizontal. The
dimensions of the bearing parts in the longitudinal direction of
the rake is approximately double the size of that of the resilient
arms 2044 and 2046.
[0143] In a practical embodiment of a resilient rake, the bearing
parts 2048, 2050 have an edge length of 44 mm. The sizes of the
other rake components are obtained in a similar manner from FIGS.
24 to 27 illustrated to scale. POM (Polyacetal, Polyoxymethylene)
and a PC/ABS blend (Polycarbonate/AcryInitrile Butadiene Styrene
blend) are considered as plastics material. Thus, with the
dimensions which may be derived from FIGS. 24 to 27, a spring mat
is obtained of which the spring properties are similar to those of
a spring core made of steel helical springs. The spring mats of
different hardness may be implemented by alterations to the
geometry and possibly the choice of modified plastics.
[0144] By the design of the resilient arms 2044 and 2046 described
above as well as the bearing parts 2048 and 2050 it is achieved
that the spring characteristic of the spring mat 2000 is
approximately linear, and larger relative movements as regards the
foamed material or filling material are avoided, which is in
contact with the lower face and/or the upper face of the spring mat
2000.
[0145] Thus in the upper left part of FIG. 24 the remainder of an
upper foamed material layer 2060 is shown, not fragmented, which
covers the resilient rakes 2000 in a finished mattress. In the
lower left part of FIG. 24 both the foamed material layer 2060 and
the resilient rake plate 2000 are fragmented, so that a lower
foamed material layer 2062 of the finished mattress is visible.
[0146] Also forming part of the finished mattress, which is not
reproduced in the drawings, are layers located above the foamed
material layers 2060 and 2062 made of natural fibres such as
cotton, wool or horsehair and a covering surrounding the entire
layered structure described so far.
[0147] FIG. 28 shows schematically a resilient rake core 3000 with
an increased spring path. It comprises two superimposed resilient
rake mats 2000-1 and 2000-2 as have been described above. Between
the two resilient rake mats 2000-1 and 2000-2, is a separating
layer 2064. In this case it may be a cotton fabric, a glass fabric,
a polyamide fabric, a plastics film or a composite material made up
of the aforementioned materials. According to the rigidity of the
separating layer, the loading of the lower resilient rake mats
2000-2 by the load resting on the upper resilient rake mat 2000-1,
is distributed to a greater or lesser extent, whereby the local
flexibility of the mattress may be adjusted.
[0148] The resilient rake core 3000 bears at the top and bottom a
foamed material layer 2060 and 2062. This entire arrangement thus
obtained is surrounded by a foamed material frame 2066 of the same
height. On the upper face of the arrangement a covering layer 2068
made of cotton is shown, on the lower face a cover layer 2070 of
wool is shown. A cover covering the whole is indicated at 2072.
[0149] In a modification, between the spring core mats and
separating layers resting thereon, separating layers may also be
provided as in the case of the separating layer 2064, in order to
achieve a load distribution and/or to allow relative movements with
low friction.
[0150] In the mattress described above the hardness may be provided
by the material and geometry of the resilient rakes and namely may
be locally variable, by different resilient rakes and/or resilient
rake segments being used, which respectively may be releasably
connected by simple mechanical latching connections. Further
possibilities for influencing the local hardness of the mattress
result from the separating layers used and foamed material layers
used.
* * * * *