Tube for a waterbed

A tube for a waterbed includes a generally cylindrical tube body having a top, a bottom, and a pair of side walls extending from the top to the bottom. The tube body defines a longitudinal axis of the tube. First and second tube ends in combination with the tube body form a watertight enclosure. A fill valve is provided through which the watertight enclosure may be at least partially filled with water. Metering walls are disposed in the watertight enclosure generally transverse to the longitudinal axis of the tube, each pair of metering walls defining a tube section therebetween. The metering walls extend across the tube body from one side to the other and are sealed to each side wall. The metering walls have a top portion that is spaced from the top of the tube body to permit the metered flow of water from one tube section to another. They may also have a bottom portion that is spaced from the bottom of the tube body. The ends of the metering walls are connected to the side walls of the tube body with soft seals, so that if the soft seals break water is not released from the watertight enclosure. The metering walls flex in the vicinity of their top openings to relieve pressure and stress on the components of the tube.

BACKGROUND OF THE INVENTION 
This invention relates to waterbeds, and more particularly to tubes for 
waterbeds. 
The advantages and benefits of waterbeds over conventional beds are 
well-known. There have, however, heretofore been some perceived 
disadvantages of waterbeds which have slowed their acceptance. One of 
these perceived disadvantages has been the presence of a hard wooden frame 
around the outside of the waterbed mattress(es) to hold the mattress(es) 
in place. 
This particular perceived disadvantage has been overcome in part recently 
by the introduction of softside waterbeds. These waterbeds use a layer of 
foam which extends as a collar around the periphery of the waterbed to 
hold the waterbed mattress in place. In soft-side waterbeds, the mattress 
is often composed of a plurality of parallel watercontaining tubes, which 
extend from head to foot of the mattress. When disposed in this manner, 
waterbed tubes substantially prevent side to side wave motion in the 
waterbed. 
However, waterbed tubes could be improved. When a user lies on his side on 
a waterbed tube mattress, his shoulder may rapidly displace the water 
under the shoulder and force it to rush to the foot of the bed. The user's 
feet are then elevated in an exaggerated manner. As the water rebounds 
from the end of the tube, it shoots back toward the head of the bed, 
creating a "teeter-totter" effect. 
Various systems, such as the foam or fiber-filled tubes disclosed in U.S. 
Pat. No. 4,221,013, address this problem, but they could be improved. For 
example, a foam-filled tube reduces the rapid water movement but does not 
eliminate the rapid displacement effect or the "teeter-totter" effect. 
Moreover, in foam-filled tubes the foam can bunch together in the filling, 
draining, moving or burping process, which significantly reduces the 
anti-wave properties. Foam is also a natural harbor for bacteria and air 
cells. The bacteria deteriorate the quality of the vinyl of which the 
tubes are made and diminish the life of the tube. Air trapped in the foam 
is released from the open cells and can cause annoying noises unless 
burped. 
Upon draining a foam-filled tube, a substantial amount of water remains in 
the foam, creating an unnecessarily heavy tube which can be difficult to 
transport and which is also subject to bacterial, fungal and/or algae 
growth. Moreover, a foam-filled waterbed tube has a higher cubic volume 
than a non-foam filled tube, with the result that shipping costs are 
increased. This is particularly a problem in export containers. 
Various foam-filled waterbed tubes have been devised to hold the foam or 
fiber in place in the tube. Unfortunately, these usually involve 
additional seals to the vinyl of the waterbed tube which can be 
uncomfortable to the user, and can, if they fail, result in a leak from 
the tube. 
SUMMARY OF THE INVENTION 
Among the various objects and features of the present invention may be 
noted the provision of an improved waterbed tube which substantially 
eliminates rapid water movement within the tube. 
Another object is the provision of such an improved waterbed tube which 
eliminates the "teeter-totter" effect. 
A third object is the provision of such an improved waterbed tube which 
solves the problem of bunching of foam or fiber, which otherwise naturally 
occurs in such tubes. 
A fourth object is the provision of such an improved waterbed tube which is 
significantly less subject to bacterial attack. 
A fifth object is the provision of such an improved waterbed tube which is 
substantially lighter in weight when drained. 
A sixth object is the provision of such an improved waterbed tube which has 
a reduced volume for shipping. 
A seventh object is the provision of such an improved waterbed tube which 
is more comfortable and less prone to leakage. 
An eighth object is the provision of such an improved waterbed tube which 
is relatively easy to burp, so as to substantially remove all the air from 
inside the tube. 
Other objects and features will be in part apparent and in pan pointed out 
hereinafter. 
Briefly, a waterbed tube of the present invention includes a generally 
cylindrical tube body having a top, a bottom, and a pair of side walls 
extending from the top to the bottom, the tube body defining a 
longitudinal axis of the tube. First and second tube ends are provided 
that in combination with the tube body form a watertight enclosure. A fill 
valve through which the watertight enclosure may be at least partially 
filled with water is disposed in one surface of the tube body. Metering 
walls are disposed in the watertight enclosure generally transverse to the 
longitudinal axis of the tube, each pair of metering walls defining a tube 
section therebetween. The metering walls extend across the tube body from 
one side to the other and are sealed to each side wall. The metering walls 
have a top portion which is spaced from the top of the tube body to permit 
the metered flow of water from one tube section to another.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Turning now to the drawings, a waterbed 11 is shown having a conventional 
softside mattress frame 13 holding a plurality of waterbed tubes 15 
extending from head to foot of the waterbed. Each tube 15 has a fill valve 
17 disposed either in the top of the tube as shown or in one end of the 
tube. 
As shown in FIGS. 2 and 3, each tube 17 includes a generally cylindrical 
tube body 19 having a top 21, a bottom 23, and a pair of side walls 25 
extending from top 21 to bottom 23. Tube body 19 defines a longitudinal 
axis 27 of tube 17. The tube also includes first and second tube ends 29, 
30 that, in combination with tube body 19 forms a watertight enclosure. As 
is known, waterbed tubes are conventionally made of vinyl with the 
necessary seams either lap seamed or butt seamed. It is preferred that the 
watertight enclosure be made using lap seams. 
Waterbed tubes 17 differ significantly from conventional waterbed tubes in 
having metering walls 31 (see FIGS. 3-5) disposed in the watertight 
enclosure generally transverse to the longitudinal axis of each tube. For 
clarity only five such metering walls 31 are shown. However, it is 
preferred that a larger number, such as seven, be used. For example, with 
seven metering walls, the first and last metering walls are preferably 
disposed approximately 12-7/8" from their respective ends of their tube, 
with the remaining five metering walls being disposed at 7-7/8" intervals 
therebetween. More metering walls can be added for a greater hydraulic 
affect (less movement). Or fewer walls can be used for a reduced affect 
(more movement). 
Each pair of metering walls 31 defines a tube section 33 therebetween, and 
the first and last metering walls define tube sections with their 
respective tube ends 29 and 30. Each metering wall extends transversely 
across the tube body from one side 25 to the other and is sealed to each 
side wall with a soft seal. A soft seal is used so that if the metering 
wall 31 separates from side wall 25 it does not tear the side wall, and no 
leak results. It should be noted that each metering wall 31 has a top 
portion (see FIG. 4) which is spaced from the top 21 of the tube body to 
permit the metered flow of water from one tube section to another. 
Preferably, it also includes a bottom portion which is spaced from the 
bottom 23 of the tube body. Each metering wall has a central wall portion 
45 which terminate in first and second flanges 47, 49. The central wall 
portion 45 and flanges 47, 49 are preferably made of a conventional 
waterbed material such as vinyl. The flanges are suitably secured to the 
tube body by the soft seals as described above. 
It is preferred that, as shown in FIG. 4, flanges 47, 49 overhang openings 
41 and 43 as indicated at 50. The flanges are resilient so that the 
portion of the flanges overhanging the openings move vertically (as 
indicated by arrows 51 ) when pressure is applied to the tube body to 
relieve stress on the seals when pressure is applied to the tube body. 
Similarly, the central wall portion is also resilient so that the 
crescent-shaped portion of the central wall may also flex up and down when 
pressure is applied. This reduces tension on the seams and extends the 
effective life of the tube. 
As is shown in FIG. 5 by a pair of seals 55, 57, each flange is secured to 
its respective side wall 25 by a suitable soft rf (radio frequency) seal. 
Alternatively, the flanges can each be sealed to the tube body by a pair 
of seals to create a double wall effect. In any event, it is preferred 
that the seals connecting the flanges to the side walls be spaced from any 
seals of the tube body itself. For example, to make the tube body, it is 
conventional to have a lap seam 59 which runs longitudinally along the 
bottom of the tube. The flange seals all terminate short of all such 
seals. Double-sealing, which the present construction avoids, would 
undesirably weaken the structural tube seals. 
Although central wall 45 is shown as solid in FIG. 4, it may also (as 
indicated in phantom at 61) have internal venting holes for allowing water 
to pass from one tube section to the next through the venting holes. 
It is preferred that the top two inches of each tube be left unseamed to 
allow for ease of burping the tubes. Air rises to the top of the tube and 
can be easily extracted by applying slight hand pressure at the end of the 
tube steadily to force the air to the fill valve. 
Tube 15 made in accordance with the present construction slowly meters the 
flow of water from one compartment 33 of the tube to the next. A user is 
unaware of the gradual displacement. There is no "rebound," so the 
teeter-totter effect is eliminated. Since there is no foam anti-wave 
material, all the negative aspects of foam-filled tubes are eliminated. 
In view of the above, it will be seen that all the objects and features of 
the present invention are achieved, and other advantageous results 
obtained. The description of the invention contained herein is 
illustrative only, and is not intended in a limiting sense.