Note: Descriptions are shown in the official language in which they were submitted.
This invention rclates gcnerally to an automatic swimming pool
cleaner and more particularly to a cleaner comprised of a car adapted to travel
underwater along a random path on thc surface of a pool vessel. This is a
divisional application of Canadian ~pplication 324,403 filed March 29, 1979.
Many different types of apparatus are disclosed in the prior art for
cleaning swimming pools. An example is United States Patent No. 3,291,145
which discloses a cleaner employing a floating head carrying high pressure
liquid dispensing hoses which sweep the pool vessel walls so as to put any
dirt thereon in suspension where it can be filtered out by the pool's standard
filtration system. As further examples, United States Patents 2,923,954 and
3,108,298 disclose cleaners in which wheeled vehicles move underwater along
the pool vessel surface to collect debris and sweep the walls.
Prior art underwater cleaners have thus far met with only limited
success for several reasons. Initially, in order to develop adequate
traction between the wheels and pool vessel surface, they have typically had
to be very heavy and cumbersome. Moreover, those underwater cleaners which
employ an electric motor have proved to be somewhat inconvenient because of
the potential shock hazard. That is, since it is normally recommended that
the motor not be operated while there are swimmers in the pool, the cleaner
2Q cannot safely be left in the pool under the control of a time clock. As a con-
sequence, the use of such cleaners has, for the most part, been restricted to
commercial applications.
Further, it is characteristic of most prior art underwater cleaners
to utilize relatively complex reversing-and steering mechanisms in order to
achieve adequate surface coverage. Such complex mechanisms are generally cost-
ly and relatively unreliable.
In view of the foregoing, it is an object of the present invention
-- 1 --
to provide an improved underwater swimmi,ng pool cleaner,
According to one aspect the invention is a swimming pool cleaner
including a car adapted to travel underwater on the surface of a pool vessel;
said car including a frame supported on traction means for engaging said pool
vessel surface; propelling means carried by said car for propelling said car
along said vessel surface; thrust means carried by said car for producing a
water flow having a component directed to produce a reaction force on said
car acting to thrust said traction means against said pool vessel surface; at
least one sweep hose having first and second open ends; water supply means
carried by said car having an inlet and an outlet; and means coupling a first
end of said sweep hose to said water supply means outlet.
According to a second aspect, the invention is a swimming pool
cleaner adapted to remain underwater adjacent the surface of a pool vessel
comprising: a frame structure including support means for engaging said pool
vessel surface; water supply means carried by said frame structure having an
inlet and an outlet; thrust means carried by said frame structure and coupled
to said water supply means outlet for producing water flow having a component
directed to produce a reaction force on said frame structure acting to thrust
said support means against said pool vessel surface; at least one sweep hose
having first and second open ends; and means coupling a first end of said
sweep hose to said water supply means outlet.
Figure 1 is an isometric sectional view illustrating a pool cleaner
in accordance with the present invention in a typical swimming pool;
Figure 2 is a side elevation view of a preferred embodiment of the
- present invention;
Figure 3 is a sectional view of a pool cleaner in accordance with
the present invention taken substantially along the plane 3 - 3 of Figure 2;
Figure 4 is a sidc view, part:ially broken away, of a pool cleaner in
accordancc with th~ prescnt invention;
~ igure 5 is a sectional view taken substantially along the plane
5 - 5 of Figure 3;
Figure 6 is a sectional view taken substantially along the plane
6 - 6 of Figure 3;
Figure 7 is a sectional view taken substantially along the plane
7 - 7 of Figure 3;
Figure 8 is a plan view partially broken away illustrating an
alternative arrangement including a linkage coupling the turbine to the third
wheel to cause random steering and a means for pulverizing leaves and other
debris sucked into the collection basket;
Figure 9 is a side elevation, partially broken away, of the pool
cleaner of Figure 8; and
Figure 10 is a sectional view taken substantially along the plane
10 - 10 of Figure 8.
Attention is now called to Figure 1 which illustrates a cutway
isometric view of a typical residential or commercial swimming pool. The
water 10 is contained within a vessel 12 generally defined by a reinforced con-
crete wall 14 poured to conform to the shape of an excavated hole. Typically,
a hole is excavated which defines a relatively deep end 16 and a relatively
shallow end 18. In conforming to the shape of the excavation, the wall 14
generally defines substantially horizontal or floor portions 19 as well as sub-
stantially vertical or wall portions 20 which rise above the intended level
of the water 10 to decking or coping 21.
Typically, filtration systems employed with swimming pools of the
type illustrated in Figure 1 include a main pump and filter 22 for taking water
-- 3 --
from the pool, f;ltering thc water, and rcturning the filtered water to the
pool. Such filtration systems employ water intake ports, such as a surface
or skimmer intake 24 and a below water level drain intake 26. The filtration
system sucks water into the intakes 24 and 26, and after filtration, returns
the water to the pool via a return line 27 and return ports 28 extending
through the vertical wall portion 20 close to the water line.
Although the typical swimming pool filtration system does quite an
adequate job of filtering the water to remove fine debris particles suspended
therein, such systems are not effective to remove debris, such as leaves,
which settle on the floor of the pool or fine particles of debris which settle
on both the floor and vertical wall portions of the pool vessel surface. As
a consequence, in order to maintain a swimming pool clean, it is necessary
to periodically sweep the wall surface, as with a longhandled brush, to place
any fine debris in suspension. Additionally, it is also necessary to periodi-
cally vacuum the pool floor to remove larger debris such as leaves.
The present invention is directed to a cleaning apparatus 30 which
travels along a random path on the surface of the pool vessel to both sweep
the walls and suck debris into a debris container carried thereby.
Attention is now called to Figures 2-7 which illustrate a preferred
embodiment of pool cleaner in accordance with the present invention.
The pool cleaner 30 is comprised of a car 32 having a frame or body
structure 34 supported on some type of movable traction means such as wheels
36a, 36b, 36c. As shown in Figure 4, the frame structure 34 can be essential-
ly pan shaped, consisting of a bottom plate or platform 38 and upstanding
sidewall 40 extending around the periphery thereof. A dome or cover member 41
is provided having depending sidewalls 42 which mate with upstanding sidewall
40.
-- 4 --
In accordance with the prcscnt invention, a turbine mechanism is
mounted within the framc structure 34 for producing rotary motion in response
to a pressured water/flow supplied thereto. The turbine 44 can be conven-
tional in design having a water inlet port 46, a water outlet port 48, and a
power output shaft 50 which is rotated in response to water being supplied
to the port 46.
The output shaft 50 extends axially in both directions from the
turbine 44 and is supported for rotation in openings through wall portions
51, 52. Small gears 54, 56 are secured to the shaft 50 at opposite ends there-
of. The gear 54 is engaged with an annular rack 58 formed on the inner sur-
face of wheel 36a as is best shown in Figures 3 and 4. The wheel 36a is
mounted for rotation on axle 59 which extends parallel to, bu~ is spaced from,
shaft 50. The gear 56 is similarly engaged with annular rack 60 formed on
the inner surface of wheel 36b mounted for rotation on axle 61. Axle 61 also
extends parallel to shaft 50 but is spaced therefrom in the direction opposite
from axle 59. In contrast to the drive or traction function performed by
wheels 36a and 36b, wheel 36c is merely a support wheel, as shown in Figures
3 and 4 mounted for rotation about axle 71. Axle 71 can be mounted for pivot-
al movement about pin 72 to better enable the wheel 36c to follow the contour
of the vessel surface.
The turbine 44 is powered by water supplied to the port 46 via con-
duit 62 coupled to outlet 64 of a water supply manifold 66. A pressure water/
flow is supplied to the inlet 68 of the manifold 66 through a supply hose 69
preferably from a booster pump 70 (Figure 1). As the turbine 44 rotates to
drive the shaft 50, both the wheel 36a and the wheel 36b will rotate.
It will be noted from Figure 3 that although the wheels 36a and 36b
rotate about parallel axes, the axes are offset with respect to one another.
-- 5 --
In other words, a line projccted botween thc axes of wheels 36a and 36b will be
skewed with respect to the planes of rotation of the wheels. As a conse-
quence of this skew arrangement, the car will avoid getting stuck against
vertical walls or barriers. That is, in its random travel along the pool
vessel surface, even if the wheels 36a and 36b simultaneously engage a large
obstacle such as the vertical wall of a step, the skewed relationship of the
wheels 36a and 36b relative to the direction of travel will produce a force
component extending parallel to the vertical wall to thus enable the car to
spin off and thus avoid getting stuck in a position from which it cannot
emerge.
It will be recalled from Figure 1 that the wall 4 of a typical pool
is shaped with a relatively large radius of curvature between the substantial-
ly horizontal or floor portions of the pool vessel and the substantially ver-
tical or sidewall portions. In other words J for structural integrity and to
facilitate water flow, many modern pools are not constructed with sharp
corners between floor and wall. In order to most effectively clean a pool,
- it is desirable of course that the car be able to traverse as much of the pool
vessel surface as possible. In other words, it is desirable that the car be
able to climb the substantially vertically oriented portions of the pool vessel
wall. In order to accomplish this, the car 32 in accordance with the present
invention is provided with water powered means for producing a thrust to in-
crease traction between the wheels 36 and the vessel surface. In accordance
with the preferred embodiment of the invention, this thrust is produced by a
water jet discharged from a directionally adjustable nozzle 90 and by a water
stream discharged from a suction of vacuum unit 91. The two thrust components
produce a substantial force extending normal to the vessel surface thereby
increasing traction between the wheels 36a; 36b; 36c and the vessel surface
-- 6 --
and enabling the car to climb vertical surfaces.
The nozzle 90 is preferably mounted on some type of universal fitting
such as a ball coupling 92 which couples the nozzle to the supply manifold
66 for receiving a high pressure water supply from booster pump 70. The angle
of the nozzle 90 is selected to yield both a downward thrust component (i.e.
normal to the vessel surface) for providing traction and a foward component
which aids in propelling the car and facilitates the car climbing vertical
surfaces and working itself out of corners. Set means (not shown) can be pro-
vided for holding the selected angle of the nozzle and valve means (not shown)
can be provided for varying the flow rate through the nozzle 90.
In use, as the car is propelled along the vessel surface by rotation
of the drive wheels 36a and 36b, the vacuum unit 91 will always discharge a
water flow having a component normal to the portion of the vessel surface on
which the car then rests. The intensity of the water flow is selected to
produce a reaction force sufficient to enable the car to climb vertical sur-
faces. As the car climbs, the combined effects of gravity, the cars inherent
flotation characteristics and the directional variations produced by the water
jet (and other effects to be discussed) cause a change in direction of travel
sensing the car to fall off the vertical surface and reestablish its travel
along another path. In order to assure that the car lands correct side up,
the car is designed to have a relatively low center of gravity; i.e. the
weight distribution of the car is selected so that its center of gravity is
close to the bottom of its vertical dimension, so as to thereby produce a
bouyant torque tending ko maintain it correct side up. The entire car struc-
ture is preferably designed to weigh very little when underwater, thereby
assuring that the hold down force produced by the water flow together with the
weight distribution of the car, will cause the car to land correct side up
-- 7 --
8~9
whenovcr it falls from a wall surface.
The car carries with it one or more sweep hoses 96 which are trailed
along and whip against the vcssel surface. More particularly, a hose 96 is
coupled to a tube 100 communicating with the interior of the supply manifold
66. The remote end of the hose 96 is left open via an orifice. Water flowing
from the manifold 66 and tube 100 through the hose 96 will exit through the
open hose end and in so doing will produce a reaction force on the hose whip-
ping it in random directions. As a consequence, it will rub against and sweep
fine debris from the vessel surface, putting it in suspension for removal by
the pools standard filtration system. A float 102 is preferably mounted
around the tube 100 to facilitate dynamic balance of the car. A valve 114 is
preferably incorporated in the tube 100 for controlling the flow rate to the
sweep hose and thus the whipping action thereof.
In the course of moving along a random path on the pool vessel sur-
face in a manner thus far described, it is of course the function of the
cleaner to clean the surface as by putting fine debris thereon in suspension
for removal by the standard filtration system.
In addition, in accordance with the invention, large debris such as
leaves are collected by the subject cleaner by the vacuum unit 91 which pro-
duces a suction close to the pool vessel surface. More particularly, a suction
or vacuum head 110 (Figures 3 and 4) extending across substantially the full
width of the car between the wheels 36a and 36b is defined in the plate 38.
The suction head 110 defines a suction opening 112 at the bottom thereof. The
opening 112 narrows down and communicates with the lower end 114 of a venturi
tube 116. An orifice 118 is mounted in the throat of the venturi tube 116 for
discharging a flow of water therethrough toward the open end 122 of the venturi
tube. Orifice 118 receives water flow via conduit 124 coupled to outlet 126
-- 8 --
8~9
on the supply manifold 66. As should be appreciated, the water discharged
from the orifice 118 produces a reduced pressure in the throat area of the
venturi tube thus producing a suction at the entrance opening 112. As a
consequence, water and debris are drawn from the vessel surface into the
opening 112 and through the venturi tube 116. The water and debris are
then discharged through the open venturi end 122 into a debris collection
container. In the embodiment of the invention illustrated in Figures 2-7,
the debris collection container constitutes a bag l24 formed of mesh material
having an entrance opening sealed around the open end 122 of the venturi tube
116 by a band 125. The bag 124 is of course removable from the venturi tube
116 for cleaning or disposal.
Reference was previously made to a supply hose 69 for supplying a
pressured water flow to the manifold 66. In order to assure that the car
does not get entangled with the supply hose 69, it is preferable that the
hose float during operation as is represented in Figure 1. The hose of
course can be caused to float by mounting suitable floats thereon. More
particularly, the supply hose 69 can comprise a one-half inch inner diameter
plastic hose, for example, having a swivel coupling 164 mounted in a first
end 160 thereof. The swivel coupling 164 is adapted to be threaded into an
outlet 166 provided in the pool vessel surface adjacent to the water surface.
A water booster pump 70 which can divert water out of the pool's standard
filtration system, provides a high pressure flow to the outlet 166. The sec-
ond end 162 of the hose 69 is coupled by a similar swivel coupling 170 to the
previously mentioned supply manifold 66.
From the foregoing, it will be recognized that a swimming pool
cleaner has been disclosed herein which is comprised of a car which travels
along a random path on the surface of a pool vessel propelled by traction
_ g _
i~lti8P9
wheels powcred by a water (Iriven turbine. As a consequence of employing the
previously discusscd watcr streams to produce a signficant traction force
between the wheels and the vessel surface, the car can be constructed of
light-weight inexpensive materials, such as plastic. By being able to uti-
lize light weight materials such as plastic, a car in accordance with the
invention can be produced quite inexpensively. Moreover, by designing the
car so as to assure full coverage of the pool vessel surface without requir-
ing complex steering and reversing mechanisms, cost reduction and reliability
improvement is further enhanced. Although a particular embodiment of the
invention has been illustrated in Figures 2-7, it should be readily apparent
that many variations can be made without departing from the spirit or scope
of the invention. Thus, for example only, an alternative arrangement is shown
in Figures 8-10 wherein, in lieu of utilizing a separate debris collection
bag, the car structure itself forms the debris container with the car cover
member 200 being perforated to permit water flow therethrough.
Utilization of the arrangement of Figures 8-10 contemplates that a
user remove the dome 200 and then clean the debris from the pan shaped frame
structure. In both the arrangement of Figures 8-10 and the arranagement of
Figures 2-7, the mesh size for the water permeable material should be select-
ed to suit a particular set of conditions. For example, in pool situations
where many leaves are encountered, it would be desirable to utilize, material
with relatively large holes so as to contain most of the leaves and enable
the water to freely flow therethrough to suspend the rest of the debris for
removal by the filter system. On the other hand, a pool with few leaves but
a heavy silt problem would preferably use a very closely woven container
material to remove the silt and reduce the load on the filter system.
In using the subject pool cleaner, it has been recognized that as
- 10 -
the leaves collcct withill the containor, the high vclocity water stream dis-
charged from the upper end of thc venturi tube continually beats the leaves
against the container screell material. As a consequence, the leaves are pul-
verized into fine particles which pass through the screen material and go into
suspension in the water from which they can be rcmoved by the pool's regular
filtration system. As a result of this action, the frequency with which the
debris must be removed from the container is considerably reduced. In pool
situations with a greater than normal leaf problem a pulverizing means 210
(Figures 8 and 9) can be incorporated in the container to more positively
pulverize the leaves. More particularly, as shown in Figure 8 a collar 212
carrying a plurality of radially extending blades 214 can be mounted on turbine
shaft 50'. As the shaft 50 rotates, the blades 214 move past fixed b]ade 216
shredding leaves therebetween.
In order for the pool cleaner to function effectively, it should
travel in a highly random manner so as to substantially cover the entire
vessel surface. Various factors operating on the car depicted in Figures2-7
will tend to produce this random motion. Such factors include the vessel sur-
face terrain, the action of the whip hose 96 and the direction of the nozzle
90. However, it is recognized that if necessary, for certain pool situations,
means can be incorporated in the car for positively randomizing the car motion.
For example, attention is called to Figures 8-10 which illustrates one such
means for varying the plane of rotation of the wheel 36c as the car moves.
In the embodiment of Figures 8-10, the axle 71' of the wheel 36c is pivoted
around pin 72' by a link 220 coupled between the axle 71' and gear 224. The
gear 224 is engaged with worm gear 226 secured to turbine shaft 50'. As shaft
50' rotates, gears 224 and 226 rotate around their axes thus moving the end
228 of link 220 in a small circle. This alternately pulls and pushes the free
-- 11 -
end of axle 71' thus pivoting it about pin 72'.
It should be recognized that other arrangcments can also be em-
ployed for achieving the random motion produced by the embodiment of Figures
8-10. ~or example only, the direction oE the nozzle 90 can be varied as the
car moves, a movable rudder can bc employed and/or the flow rate through the
sweep hose can be varied.
From the foregoing, it will be recognized that an improved swimming
pool cleaner has been disclosed herein which is capable of randomly traveling
on the pool vessel surface and collecting debris therefrom as well as dis-
lodging debris from the surface for collection by the pool's standard filtration
system. Although a preferred embodiment of the invention has been illustrated
herein, it is recognized that numerous variations and modifications can be
made therein without departing from the spirit and scope of the invention.
Thus, for example only, tractions means other than the round wheels can be
employed for increasing traction area or for facilitating travel of the car
over low obstructions, such as a hose. Similarly, means can be provided
for changing drive direction in special pool situations where the car could
get stuck against some obstacle. It should also be recognized that although
the preferred embodiments of the invention illustrated herein employ a
booster pump 70 for optimum performance, the booster pump could be eliminated
in a low cost system and the turbine could be driven by water flow from the
main pump.
