Note: Descriptions are shown in the official language in which they were submitted.
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WATER MATTRESS SUPPORT FOR CONVENTIONAL MATTRESSES
BACKGROUND OF THE INVENTION
The invention relates to the field of bed structures
and more particularly to beds utilizing water-filled
mattresses.
According to the conventional bed structure, an inner-
spring mattress is supported by a box spring which is pro-
vided with legs, a footboard and headboard. The box spring
consists of a cloth-enclosed wooden frame having rows of
coil springs. The purpose of the box spring is to increase
the comfort of the sleeping person by providing additional
resiliency. However, the conventional structure does not
provide the optimally-distributed support for the body, and
pressure-points are caused on the heavier projecting parts
of the body. Also, the conventional structure tends to sag
towards the middle, particularly when two persons are on
the bed and this problem increases as the box spring be-
comes worn.
Waterbeds have become a widely accepted alternative to
conventional mattress structures in recent years. Accor-
ding to this structure, both innerspring mattress and bo~
spring are replaced with a water-filled bladder which is
generally heated and provided with a wave-dampening con-
struction. While a more evenly-distributed support for the
body is provided by a waterbed, one of the disadvantages of
this structure is that conventional bedding cannot be
fitted to the waterbed. So-called hybrid mattresses have
also been developed, such as those disclosed in United
States patents numbers 4,062,077 and 4,145,781 both issued
to Autrey. In these designs, the conventional innerspring
mattress is replaced with a combination foam and water
mattress which has the external dimensions and appearance
of an innerspring mattress. These hybrid mattresses simi-
larly have not been found to be completely satisfactory.
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A need therefore exists for a bed structure which
allows the use of a conventional innerspring mattress yet
provides improved support.
SUMMARY OF THE INVENTION
The present invention provides an improved bed struc-
ture which utilizes one or more water-filled bladders to
replace the box spring. Preferably, the water-filled
bladders are shallower than for a standard waterbed, and
have increased wave dampening features. Three separate
bladders are preferred for a double-si~ed or larger mat-
tress. A solid frame may be used to contain the water
bladders and also retain the innerspring mattress in posi-
tion. According to an alternate embodiment, the water
mattress support has an exterior foam frame. A heater may
also be provided to heat the water mattresses.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate preferred embodiments of
the invention:
Figure 1 is a perspective view of a first embodiment
of the invention in expioded form;
Figure 2 is a perspective view of a second embodiment
of the invention with the conventional innerspring mattress
in phantom outline; and
Figure 3 is a cross-sectional view taken along line
3-3 of Figure 2.
DETAILED DESCRIPTION OF A PREFERRED
EMBODIMENT OF T~E INVENTION
Referring to Figure 1, a conventional innerspring
double mattress is indicated as 1. Typically such mattres-
ses are 80 inches long by 60 inches wide by 5 to 7 inches
thick. The conventional innerspring mattress is supported
on the novel mattress support of the invention which
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consists of a wooden frame 2 and two or three water
mattresses or bladders 3.
The wooden frame 2 has interior measurements 60 inches
by 80 inches to receive the innerspring mattress and is
constructed of 2-inch thick pine. The wooden frame 2 is in
turn supported on a pedestal or a 9-legged frame. It has
sides which are 5 inches high in the center, with raised
corners on each end of each side which are 7 or 8 inches
high. The raised corner portions extend approximately 6 to
1~ 8 inches from each end. The purpose of the higher corners
is to retain the innerspring mattress in place when it sits
on top of the water mattresses. A standard waterbed heater
4 may be provided on the frame and an interior waterprooE
liner is used to line the wooden frame. The frame is able
to be broken down for shipping.
The water mattresses or bladders 3 rest inside the
frame. They are approximately 4 inches thick, which is
shallower than standard waterbed mattresses. In the case
of the double water mattress system, each mattress will be
approximately 30 inches wide by 80 inches long. In the
case of a triple mattress system each will be 20 inches
wide. For reasons set out below, the triple mattress
system is preferred for a double bed size. Modifications
in these dimensions will be apparent for larger or smaller
bed sizes.
The water mattressess 3 are preferably not standard
waterbed mattresses. As indicated, they are shallower than
standard mattresses (which are typically 8 inches thick).
They will generally be formed of twenty millimeter thick
vinyl and incorporate either a baffling system or the other
standard water-dampening means used for waterbed mattres-
ses.
A second embodiment of the invention is shown in
Figures 2 and 3. In this embodiment, the conventional
innerspring mattress 1 is supported on a base consisting of
a wooden deck 6 to which a foam frame 7 is attached. Again
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three water bladders 3 are utilized. The innerspring
mattress is shown in phantom outline in Figure 2.
In the embodiment shown in Figure 2, the wooden deck 6
has the same exterior dimensions as the innerspring
mattress and ideally is four inches thick7 constructed of a
frame of 1 inch by 4 inch planks with a plywood deck. The
foam frame preferably is about 4.5 inches thick, and
extends inwardly six inches along the bottom surface and
four inches along the top surface, with an inwardly sloping
interior face. The lower edge of the foam frame is
indicated by dotted line 14 in Figure 2. The purpose of
the foam frame is so that the individual can sit
comfortably on the edge of the bed.
The foam frame 7 and exterior surface of the wooden
deck 6 are covered by mattress ticking as follows to give
the appearance of a conventional box spring. One edge of a
sheet of ticking 18 is stapled to the upper surface of deck
6 so that it will be positioned under edge 15 of foam 7.
Foam frame 7 is then glued in position onto the top surface
of wooden deck 6 and ticking 18 is drawn around foam 7,
down the vertical edge of wooden deck 6 and is stapled in
place at location 19. This gives the construction the
exterior appearance of a box spring, and allows a certain
freedom of compression in the foam frame.
In the embodiment shown in Figure 2, a low-wattage
waterbed heater 4 can again be used to heat the water
bladders. Such standard waterbed heaters are electrically
controlled. The water bladders have preferably two liners
surrounding them, as shown in Figure 3. One liner 10
extends under and over the top edge of the bladders, while
a second liner 11 extends completely over the bladders.
These liners protect the water mattresses from puncture and
protect the heater and the rest of the bed from leakage.
By using two liners rather than a single envelope, access
is maintained to the water mattress valves.
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The wooden deck 6 is supported on a steel frame 12
which has a number of legs.
As shown in cross-section in Figure 3, when a party
sits on the edge of the bed, the outer foam frame will
compress into a substantially rectangular flattened portion
which is more comfortable and has better support than would
the edge of the water bladder a]one. As previously
indicated, the three-bladder arrangement is preferred for a
double mattress as the provision of two bladders alone will
tend to allow both parties to roll towards the center
joint. With three bladders, each individual will tend to
rest on his or her own side of the bed.
One advantage of this system is that the heater will
gently heat the underlying water mattresses and the heat
will penetrate through the standard innerspring mattress
also to keep the mattress and sheets warm for the user.
Standard means of wave-dampening may be used, such as
baffling and fibre, but additional wave-dampening, such as
by the addition of more than the standard amount of
dampening fibre is preferred. While the use of a
conventional innerspring mattress has been specified,
obviously other forms of mattress such as foam mattresses
will also be suitable on the water mattress support of the
invention.
It has been found that the use of the water mattress
support of the invention provides improved support for the
user on a conventional inner spring mattress, while allow-
ing the user to continue to use standard bedding for the
innerspring mattress. Also the user can adjust the firm-
ness of the mattress support by adjusting the amount of
water in the mattress. The benefits of improved support of
a waterbed are obtained with about half the weight of a
traditional waterbed.
Various modifications and alterations of the structure
above-described will be apparent to those skilled in the
art without departing from the spirit of the invention, the
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scope of which is to be interpreted in terms of the
appended claims.
