Vacuum system for swimming pools

The customary method to prepare the pool bottoms in order to install the vinyl liners is with even, smooth surfaces. Difficulties occur when draining a vinyl liner pool in order to change the water, repair the liner, clean the grease from the liner, or remove the impurities from the pool bottom. In the method which I propose, the pool bottom is finished with plastic or rubber tiles which are pitched in the ground. The upper surface of the tiles is deeply impressed with geometrical designs and cramped channels which allow flow of the underliner air towards a permanent vacuum system at any time. Thus, whenever it is necessary, the liner is sucked to the pool bottom by higher pressures than the normal water pressure of the pool, and the liner maintains its shape firmly until the pool is able to be refilled.

This improvement relates to a system which prepares the pool bottom with 
special plastic or rubber tiles and a vacuum network system before 
installing the vinyl liner. 
It is known that vinyl liners installed on pool bottoms are prepared in 
even, smooth surfaces. Usually the bottom finishes of pools are: tamped 
and trowelled sand to uniform smoothness, sand plus foam board or 
composition board, pool pad cement, or reinforced concrete. The liner is 
installed by sucking it into place using commercial vacuum cleaners. Prior 
to installing the liner the sources of air leaks must be reduced. A small 
section of the liner is opened up beading just large enough to insert the 
vacuum hose. The gap is closed with wet rags to prevent air leakage around 
the hose. Turning the vacuum on to pump out the air, the liner will be 
sucked in place and at the same time the final adjustments to the liner 
for removing wrinkles can be made. When the liner is well sucked in place, 
filling the pool with water can start. Further a precautions should be 
taken when draining a vinyl liner pool for different reasons. New vinyl is 
very flexible and stretchy at first, but as it ages it loses some 
stretchability and tends to shrink. The powerful water pressure prevents 
any change in shape of the liner as long as the water remains in the pool, 
but if the water is removed for any length of time, the liner will shrink. 
For these reasons the instructions forbid the removal of the water from a 
pool unless absolutely necessary and replacement of water as soon as 
possible. When the water has to be changed, the instructions advise only 
to change it down to the 42" mark without disturbing the fit in the hopper 
section. No matter how high the quality and maintenance of a pool 
skimmer-filter system is, it can not replace a periodical complete change 
with fresh water. In the course of time the vinyl liner becomes dirty and 
it must be cleaned and degreased, and impurities heavier than water will 
lie on the bottom so the pool must be emptied. Also the pool bottom must 
be emptied and dried when the liner needs to be repaired. These 
necessities of emptying are in opposition with the actual instructions and 
requirements to save the vinyl liner. 
I have found that these disadvantages may be overcome. It is possible to 
keep the vinyl liner sucked on the pool bottom when the pool needs to be 
emptied. For vinyl liner pools, it is possible to accomplish a vacuum 
network system when the pool hole is excavated and before the pool bottom 
preparation. The vacuum network system connects each plane of the bottom 
and is able to suck the air apart from each plane, the planes being 
separated between them by smooth stripes. Every bottom plane is paved with 
plastic or rubber tiles, their upper surfaces being deeply impressed with 
geometrical designs and cramped channels between them to allow the flowing 
of the vacuumed air. The tiles are fixed in the ground by plastic nails. 
Every bottom plane has one or more tiles connected to the vacuum network 
system by special drain pipes which fix these tiles in the ground instead 
of plastic nails. When the pool needs to be emptied, the network is 
connected to a device called separator which is capable of separating air 
from water, and to a vacuum pump. If the vinyl liner is torn somewhere, 
the torn plane is isolated from a gate valve and the liner of this plane 
will not be sucked in rendering it useless. The vacuum system can exert 
higher forces on the liner than the pool water forces. These pressures are 
maintained automatically by a vacuum pump starter activated by limited 
pressures until the work is completed. So it is possible to change the 
water periodically, to repair the liner, to clean up the liner of dirt and 
grease, and to remove the impurities from the pool bottom, without 
endangering or compromising the vinyl liner. It is not necessary to 
purchase the separator and the vacuum pump, because service stations can 
bring them and perform the job when required.

When the perfect sides and floor measurements of the pool have been 
achieved, the vacuum network will be installed concomitantly with the main 
drain 17, and the plumbing FIGS. 1, 2. The vacuum network connects each 
plane of the pool bottom to the upper surrounding pipe 7, FIGS. 1, 2, 3, 4 
through the pipes 1, 2, 3, 4, 5, 6, FIG. 1. The pipes are buried in the 
ground about 5". Pipe 8 FIG. 4 connects the network to the separator and 
vacuum pump. The accomplished network is pressure tested to insure an 
absolute reliability. Then the network is plugged. The pool bottom can be 
of any finish, but the sand bottom finish is the cheapest and the most 
suitable. The smoothness and evenness of the bottom sand will not be 
determinant for the liner. The bottom is shaped with a thin layer of about 
2" of sand 31, FIGS. 7, 9, into the distinct geometric pattern of the 
pool. The sand bottom will be paved with plastic or rubber tiles and 
styrofoam or foaming-rubber stripes. Tiles 12, FIGS. 5, 7, 8, have their 
surfaces deeply impressed with geometrical designs. The designs can be 
squarer as in FIG. 10, hexagonal as in FIG. 11, circular as in FIG. 12, or 
any other regular geometrical figure either polygonal or curvilinear. The 
channels of the tiles are cramped enough to allow the movement of the 
vacuum air but the vinyl liner is protected against puncture. This means 
that the channels can have a width of 1/32" to 1/64". The tiles are used 
to pave the different planes of the bottom. The styrofoam or 
foaming-rubber stripes 11, FIGS. 5, 6, 7, are placed on the corners and 
edges separating the bottom planes between them, and rounding the 
sharpness of the border. First, the tiles connecting the bottom planes to 
the vacuum network system are placed. Each plane is connected by a minimum 
of one tile to a pipe of the vacuum network FIGS. 5, 9, 10, by means of 
the drain pipes 18 and 19, FIG. 9. The drain pipes 18 and 19 are flexible 
and air-tight connected between them by means of the gaskets 20 and 21 and 
the elastic blades 29 and rigid ribs 28, FIG. 9. The next step is the 
laying of the tiles 12, FIGS. 5, 7, 8. A pattern iron tile is tamped until 
its mark impresses the sand and through its central hole an iron nail is 
driven into the ground to mark a hole. These being achieved, tiles 12 are 
easily put in place and fixed in the ground by plastic nails 15, FIGS. 7, 
8. The plastic nail 15 is notched by a series of elastic blades, which 
will clamp the nail into the plastic ground. About 4" to the borders the 
tiles 12 are cut to reach the shape of the covered plane. About 1" to the 
margin, the tile channels are filled with synthetic resin 13, FIG. 7, and 
all seams between tiles and stripes are taped with 11/2" wide masking tape 
14, FIGS. 7, 8. To complete the vacuum network system, the separator 22, 
FIGS. 5, 6, and the vacuum pump 23, FIG. 5 are connected to pipe 8 as in 
FIG. 5. This vacuum system will be used for installation of the liner and 
whenever the pool must be drained. The vinyl liner 16, FIG. 7 is installed 
as usual. The vacuum air gets into the vacuum system by the holes 30, 
perforated through the drain parts 18, FIG. 9. The gate valves 9, FIG. 4, 
separate the different planes of the pool bottom in case the vinyl liner 
is broken somewhere. To have a clean pavement and a carefully rigging up 
of the tiles, the head of the nails 15, FIGS. 7, 8, must be at the same 
level as the tiles. So, when the nail 15, FIGS. 7, 8, has 1/2" to reach 
its place, it is cleaned by blowing the hole with compressed air. To have 
a clean vacuum system it is necessary to clean the paved pool bottom using 
a household vacuum before installing the vinyl liner 16, FIG. 7. The 
separator 22, FIGS. 5, 6, is necessary when the pool is filled. If the 
liner is broken, it is possible to detect the place of deficiency by 
seeing the water level in the glass tube 27, FIG. 6, and handling the gate 
valves 9, FIG. 4. When the separator becomes full of water, the gate 
valves 24, 25, FIG. 6, are closed and the gate valve 26 allows the water 
out.