Note: Descriptions are shown in the official language in which they were submitted.
106106Z
This invention relates generally 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 the surface of a pool vessel.
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 1;~;-
ted 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, thoseu~derwater cleaners
which employ an electric motor have proved to be somewhat inconvenient
because of the potential shock hazard. That is, since it is normally re-
commended that the motor not be operated while there are swimmers in the
pool, the cleaner cannot safely be left in the pool under the control of
a time clock. As a consequence, 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 costly and relatively unreliable.
In view of the foregoing, it is an object of the present inven-
tion to provide an improved underwater swimming pool cleaner.
Briefly, the present invention is directed to a swimming pool
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cleaner including a car adapted to travel underwater on the surface of a pool
vessel; the car including a frame supported on traction means for engaging the
pool vessel surface; water supply means carried by the car having an inlet and
at least one outlet; turbine means carried by the car coupled to the water
supply means outlet; drive means coupling the turbine means to the traction
means for drivingly rotating the traction means in response to water supplied
to the turbine means for propelling the car along the vessel surface; thrust
means carried by the car for producing a water flow having a component direc-
ted to produce a reaction force on the car acting to thrust the traction means
against the pool vessel surface; debris container means and debris suction
means carried by the car; the debris container means including an entrance
opening; the debris suction means including a suction entrance located on the
car in close proximity to the vessel surface and a suction exit coupled to
the debris container means entrance opening.
In accordance with a further aspect of the invention, a car wheel
geometry is employed which produces a sidewise force componentwhen the car
wheels engage a vertical surface to thus cause the car to spin off and free
itself from the surface without necessitating a reversal of driving direction.
In accordance with a still further aspect of the invention, the car
structure is configured so that its center of gravity is close to the bottom
of its vertical dimension so as to produce a torque tending to maintain it
correct side up when on the pool bottom.
In accordance with a still further aspect of the invention, means
are provided on the car for producing a suction adjacent to the vessel sur-
face for pulling debris into a collection basket or bag carried by the car.
In a preferred embodiment of the invention, the car is formed of
a platform supported on three wheels which engage the pool vessel surface.
Two of the wheels are driven through gearing by a turbine which in turn is
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powercd b~ water flowillg thcreto through a supply hose. In order to achieve
the aforementiollcd spinoff effect, the two driven wheels are mounted for
rotation about parallel, but spaced, axes. As a consequencc, the leadinO
edges of thc driven wheels lie on a line which is not perpendicular to their
direction of travel thus enabling the car to spin off obstructions and steep
surfaces. The third wheel is mounted for rotation on an axis which pivots in
a plane parallel to the plane tangential to the wheels so that this third
wheel may be differently oriented for dif~erent pool surface slopes, there-
by helping to randomly steer the car. Alternatively, positive drive means
such as a linlcage to the turbine can be provided to gradually pivot the
third wheel or vary the discharge angle of a water jet to assure random car
movement.
The water flow producing a force component perpendicular to the
vessel surface is preferable developed by diverting a low volume, high
velocity water flow from the supply hose to an orifice to thus pull water
into the lower end of a venturi having a directional component extending
perpendicular to the car platform which water is then discharged at the
venturi~s upper end. The force reaction presses the wheels against the pool
vessel surface to thus develop significantly greater traction for propul-
sion than the weight of the car alone could provide. As a consequence, the
car can be constructed of relatively light and low cost materials and have
the capability of climbing vertical surfaces. The suction produced adjacent
the vessel surface by the water being pulled into the lower tube end draws
debris from the pool surface into a collection basket carried by the car.
Although a single water flow is used in the preferred embodiment of the
invention for providing the primary hold down force as well as suction for
- picking up debris, it will be readily recogni~ed that separate flows could
be provided for this purpose if desired.
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In accordance with a still further aspect of the invention, means
are provided within the collection basket for pulverizing leaves so that the
remains can then be discharged and put in suspension in the pool water for
later removal by the main filter system.
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
pr0sent invention taken substantially along the plane 3-3 of Figure 2;
Figure 4 is a side view, partially broken away, of a pool cleaner
in accordance with the present invention;
Figure 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 alter-
native arrangement including a linkage coupling the turbine to the thirdwheel 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.
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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
concrete 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 substantially 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 from the pool, filtering the water, and returning 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 fil-
tration, returns the water to the pool via a return line 27 and return
ports 28 extending throughl,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 periodically vacuum the pool floor to remove larger debris
such as leaves.
The present invention is directed to a cleaning apparatus 30
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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 pre-
ferred 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
essentially 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.
In accordance with the present invention, a turbine mechanism is
mounted within the frame structure 34 for producing rotary motion in
response to a pressured water/flow supplied thereto. The turbine 44 can be
conventional 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
thereof. The gear 54 is engaged with an annular rack 58 formed on the inner
surface 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, but 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.
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Axle 71 can be mounted for pivotal 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
conduit 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 36 b 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. In other words, a line projected between the axes of wheels 36a
and 36b will be skewed with respect to the planes of rotation of the wheels.
As a consequence 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 relation-
ship 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
substantially horizontal or floor portions of the pool vessel and the sub-
stantially vertical or sidewall portions. In other words, for structural
integrity and to facilitate water flow, many modern pools are not construc-
ted 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
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car 32 in accordance with the present invention is provided with water
powered means for producing a thrust to increase traction between the wheels
36 and the vessel surface. In accordance with the preferred embodiment of
the invention, th;s 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 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
forward 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 provided 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 surfaces. 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
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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 to maintain it correct side up. The
entire car structure is preferably designed to weigh very little when under-
water, 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 whenever 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 vessel 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 whipping it in random directions. As a consequence, it will rub
against and sweep fine debris from the vessel surface, putting it in sus-
pension 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
surface 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
produces 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
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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 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 124 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
20 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 sur-
face. 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 second end 162 of the hose 69 is coupled by a similar swivel coupling
170 to the previously mentioned supply manifold 66.
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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
wheels powered by a water driven turbine. As a consequence of employing the
previously discussed water streams to produce a significant traction force
between the wheels and the vessel surface~ the car can be constructed of
light-weight inexpensiue 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 assurefull coverage of the pool vessel surface without re-
quiring complex steering and reversing mechanisms, cost reduction and
reliability improvement is further enhanced. Although a particular embodi-
ment 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 arrange-
ment of Figures 2-7, the mesh size for the water permeable material should
be selected 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
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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
the leaves collect within the container, the high velocity water stream
discharged from the upper end of the venturi tube continually beats the
leaves against the container screen material. As a consequence, the leaves
are pulverized into fine particles which pass through the screen material
and go into suspension in the water from which they can be removed by the
pools ~egular 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 then normal leaf problem a pul-
verizing means 210 (Figures 8 and 9) can be incorporated in the container
to more positively pulverize the leaves. More particula~ly, 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 blade 21~ 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 Figures
2-7 will tend to produce this random motion. Such factors include the vessel
surface 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 711 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
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their axes thus moving the end 228 of link 220 in a small circle. Thisalternately pulls and pushes the free end of axle 71' thus pivoting it about
pin 72'.
It should be recognized that other arrangements can also be em-
ployed for achieving the random motion produced by the embodiment of Figures
8-lO. For example only, the direction of the nozzle 90 can be varied as the
car moves, a movable rudder can be employed and/or the flow rate through the
sweep hose can be varied.
From the foregoing, it will be recognized that an improved
swimming p~ol cleaner has been disclosed herein which is capable of randomly
traveling on the pool vessel surface and collecting debris therefrom as well
as dislodging debris from the surface for collection by the pools standard
filtration system. Although a preferred embodiment of the invention has been
illustrated herein, it is recognized that numerous variations and modifi-
cations 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 provide 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.
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