Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to waterbeds, and in particular
to waterbed mattresses.
Waterbeds in the past have usually been made with a
mattress consisting of a large, watertight bladder covered by
mattress ticking, and a heavy sup]porting structure or frame to
maintain the shape of the mattress and support the heavy weight
of the water filling the bladder. A difficulty with this type
of waterbed is that it cannot be moved without draining the
mattress, and in view of the large quantity of water, this is
time-consuming and wasteful since the water is usually not re~
used. A further difficulty with these waterbeds is that a leak
in the bladder can cause extensive damage.
Attempts have been made to overcome the weight problem.
one example of this is shown in U.S. Patent No.3,689,949 issued
to J.D. Weinstein. Weinstein suggested the use of a base for the
water bladder which was hollowed out on its top side in a shape
to conform to the general shape of the human body. It was
suggested that this structure would effectively reduce the weight
of the water above those areas of the mattress which supported
the least weight. However, this mattress was unusually bulky.
Another attempt to overcome the weight pxoblem of
conventional waterbeds is shown in U.S patent No. 3,789,442
issuèd to S. Tobinick. This patent shows a hollowed out foamed
flexible material which receives a liquid filled bladder. This
bladder is also covered by a foamed flexible material. It would
seem that the benefits achieved would be accompanied by a lost
flotation effect.
A problem with both the Weinstein and Tobinick
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approaches is that these beds are very expensive to manufacture.
In order to solve the problem of leaking bladders, it
has been proposed to make a separate watertight cover or envelope
to enclose the main mattress bladder, so that if a leak occurs
in the bladder, the water will be contained by the outer
watertight cover. A problem with this solution, however, is that
it must be possible to open the outer cover to insert the
bladder, to fill it, and to empty it. This requires a large
watertight closure which itself is prone to leakage.
It is an object of the present invention to provide a
lightweight easily transportable flotation pad having a double
wall to protect against leaks and which can be used to convert
any ordinary bed into a waterbed.
According to the invention there is provided a mattress
pad comprising a rectangular impervious inner bladder having a
top side containing a valve. A rectangular impervious outer
bladder iB encloses the inner bladder. The top side of the outer
bladder has an opening surrounding the inner bladder valve to
allow access thereto.
A mattress cover surrounds the outer and inner
bladders. The mattress cover includes an upper side constructed
of quilted mattress ticking with an integral thermal barrier
layer, located therein, a bottom side, and peripheraI sides
having an elongate zippered opening to allow insertion of the
outer and inner bladders and the filling thereof.
Preferred embodiments of the invention will now be described
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by way of example, with reference to the accompanying drawings,
in which:
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Fig. 1 is perspective view of a flotation mattress pad
having two inner bladder assemblies;
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Fig. 2 is an enlarged sectional view of the flotation
~¦ mattress pad taken along lines 2-2 of Fig. 1;
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Fig. 3 is a plan view of a portion of the mattress pad --
indicated in Figure 1 by circle 3 showing the quilting design
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Fig. 4 i8 a perspective view similar to Fig. 1 but
15 showing a mattress pad with a 6ingle inner bladder with retaining
straps; and
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Fig. 5 is a perspective view of the underside of the -
mattress pad of Fig. 1.
A flotation mattress pad 8 is shown in an open position
in Fig. 1. A zipper 20 is used to removably affix a top of a
' mattress cover 14 to a side of the mattress cover 14. Disposed
within the mattress cover 14 are two double bladder assemblies --
15, each bladder assembly 15 including an outer bladder 12 which
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surrounds an inner bladder 10 which contains a valve 16 therein,
which valve is used to fill the inner bladder 10 with a fluid
such as water. The flotation mattress pad in Fig. 1 is for a
wider bed, such as a standard size double mattress bed, a queen
size mattress bed or a king size mattress bed, and appropriately
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contains two half-width, full length bladder assemblies 15.
Alternatively, rather than using the two half-width outer
bladders, a sin~le full width outer bladder may be employed (not
~ shown). In such employment, the bladder would have two circular
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openings 17 in its top side positioned to permit access to the
valve 16 in each inner bladder 10. Utilization of two half-width
inner bladders 10 and outer bladders 12 reduces the transmission
of waves caused by one user of the flotation mattress pad 8 to
a second user laying beside the first. The mattress pad 8 is
preferably about 5 centimetres (2 inches) thick; however, it may
be as thin as 2.5 centimetres (1 inch) or as thick as 10
centimetres (4 inches).
Fig. 2 is a sectional view of the flotation mattress
pad 8 taken along lines 2-2 of Fig. 1. The mattress cover 14
surrounds the outer bladder 12 which itself surrounds the inner
bladder 10 which holds the fluid 44 therein. The outer bladder
12 may be made of a thinner material than the inner bladder 10.
For example the outer bladder could be made of 10 mil vinyl and
the inner bladder made of 20 mil vinyl. Further, it is also
useful when filling, in order to ascertain that the inner bladder
10 i8 correctly aligned with respect to the outer bladder 12, to
have the inner bladder 10 made of a coloured material, and the
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~;j outer bladder 12 made of a tran~parent material.
The upper side 40 of the mattre6s cover 14 iB compoBed
of a mattress ticking 26 which iB peripherally edged by a hem 18
~ which binds the outside edges of the layers of the mattress
;l 5 ticking 26 to each other as well as securing one side of the
zipper 20 to the mattress ticking 26. The mattress ticking 26
itself i5 composed of a top polye6ter woven cloth 28, which i8
above a non-woven polyester filling 30, which is above a
;~ polyurethane foam layer 32, which is above a thermal barrier 34,
which is above a bottom polyester cloth 37, all of which are
quilted together. The thermal barrier layer 34 consists of a
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thin plastic film 35, reflective on both sides, which is attached
to one side of a felted sheet 36. The other side of the zipper
20 iB secured to an upper edge of a side ~urface 22 of the
mattress cover 14. An additional hem 19 secures a lower edge of
the side surface 22 of the mattress cover 14 to the bottom 24 of
the mattress cover 14.
As an alternative to the construction of cover 14, the
upper side 40 could be made out of lambswool or conventional
mattress ticking. Also, cover 14 could be made reversible, with
upper side 40 having lambswool on one side and normal mattress
ticking on the other side. With a full zipper 20 around the
periphery of cover 14, mattress cover 14 could be turned inside
out to make the upper surface either lambswool or mattress
ticking.
Optional attachin~ devices, such as flaps 21 may be ~
provided at the corners and along the sides of cover 14. Flaps ~ -
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21 are provided with grommets 23 for attaching light rope or
straps 25 to mattress pad ~ for tying down the mattress pad where
it is used in a mobile location such as in a truck, a recreation
vehicle or a boat. Alternatively, straps 25 could be attached
directly to cover 14 or to flaps 21 by being sewn in place, and
such straps could be provided with hook and loop type releasable
fasteners on the ends of the straps so that they could surround
an anchoring device or even another conventional mattress located
under mattress pad 8.
Individual users who are prone to arthritis or simply
those who prefer a pre-warmed bed may choose to utilize a
~ conventional water bed heater in conjunction with the flotation
`~ mattress pad 8. The heater would normally be located between
bottom 24 and outer bladder 12.
In order to better facilitate the utilization of fitted
bed sheets in standard sizes the flotation mattress pad may be
marginally shortened and narrowed in order to provide a space
between the peripheral adges of the bed mattress and the
peripheral edges of the mattress pad when viewed in plan.
; Fig.3 is an enlarged plan view of the mattress ticking
26 showing the top side 40 of the mattress cover 14, having a
decorative quilting stitching 38 which holds all the layers
together.
Referring next to Figs. 4 and 5, a mattress pad 50 is shown
which would be suitable for each one of a set of twin beds, or
a single bed. A single bladder assembly 15 shown in chain dotted
lines in Fig. 4 would be used inside an appropriateIy sized cover
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~-, 14. A flotation mattress pad for a single bed is sufficiently
light that a child might be able to pull it off the bed. ~or
this reason the mattress cover may be provided with two outer
safety straps 52 attached to the underside or bottom 24 of cover
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, 5 14. One strap would encircle each end of a conventional bed ~;~
mattress to secure mattress pad 50 in place. The two safety
straps are about 7.5 centimetres (3 inches) wide, are formed of
elasticized fabric, and are sewn between opposed bottom hems 19
of mattress cover 14. In addition, inside mattress cover 14, as
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10 seen in Fig. 4, three non-stretch inner straps 54 span from `~
opposite bottom side hems 19 of mattress cover 14, across the top
of the bladder as~embly 15 to hold bladder assembly 15 inside
mattress cover 14. Straps 54 are about 7 to 10 centimetres in
~;width and are made of the same material as side surfaces 22,
which is a felted synthetic material flame treated to increase
tear strength, but yet remain breathable. However, straps 54
could be made of any suitable webbing or elasticized material,
if desired. Straps 52, 54 are optional, and usually are not
required at all on the larger mattress pads containing two
bladder assemblies 15. However, straps 52, 54 could be employed
in the embodiments shown in Figures 1 to 3 if desired.
Where the mattress pads of the present invention are used
in an unheated location, such as in an automobile, a recreation
vehicle or a truck in the winter time, the inner bladders may be ~`
filled with an antifreeze solution such as ethylene glycol or
propylene glycol to prevent freezing. ~
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