Note: Descriptions are shown in the official language in which they were submitted.
2(190195
SELF _P_ROPELLED
SUF3ME32SIF3LE_SECTION_CI~ElaNER _AZyn__M_~TI3yI7
1. Field of the Invention
The invention generally relates to suction cleaners for
use on surfaces submerged in a liquid. The suction cleaner
i
is attached to a flexible hose and pump for its source of
suction. The invention relates to a device for automatically
cleaning the submerged surfaces of swimming pools and the
like.
' 2. Description of Background Art
I
Self-propelled suction cleaners are customarily used for
cleaning the submerged surfaces of pools and in particular,
I
,~15 swimming pools having various surface finishes and contoured
shapes. Various techniques have been employed in the
mechanisms that drive these self-propelled cleaners. Three
of the more common mechanisms use either a shut off valve,
turbine drive or drive wheels. In some cases, combinations
of these mechanisms are used.
The United States Patent No. 4,536,908 issued to Johann
N. Raubenheimer on August 27, 1985 discloses a suction cleaner
for a swimming pool that is supported on a bogie or truck
assembly with inclined supporting feet. The bogie assembly
?.
2090195
is mechanically rocked by means of a turbine through which
water is pulled by suction to cause the cleaner to move. In
order to change the direction of path of the cleaner, a second
turbine drives a hose connection at the top of the cleaner in
opposite directions with long periods of dwell in between.
In other words, the device is continuously driven in the
forward or turning directions.
A turbine driven swimming pool cleaner is also disclosed
in the United States Patent No. 4,939,806 issued to Carl F.
Supra on July 10, 1990. In this Supra device, a cleaner
having a head is mounted on wheels. There is a suction
passage and a propeller which is driven by the turbine and
which propels the head. A rudder, which is oscillated via a
gear train driven by the turbine, is used to vary the
direction of movement of the head.
A turbine and wheel styled device is disclosed in the
United States Patent No. 5,099,535 issued on March 31, 1992
to Daniel J.V.D. Chauvier, Cleaner for Submerged Surfaces.
In this Chauvier device, a cleaner for a submerged surface
comprises a body that defines a suction passage and pressure
passage. The suction passage extends between an inlet and
outlet in the body and is connectable to the inlet of a
filtration system by flexible hose. A second hose connects
the inlet on the device to an outlet of the system. Water
flowing under pressure to the inlet drives a turbine which in
3
_ 2000~0~
turn drives hind wheels to displace the apparatus over the
surface while debris or the like is sucked up through the
suction passage and out through the hose that is attached to
the filtration system. The suction and return hoses are those
of the flexible kind typically used in swimming pool cleaning
systems.
In the United States Patent No. 4,208,752 issued to
Helmut J. Hofmann on June 24, 1980, an apparatus for cleaning
swimming pools in a stepwise movement over the pool walls
comprises a balanced operating head having an inlet and an
outlet, the outlet adapted to be swivelably connected to a
longitudinally resilient and flexible suction hose. The inlet
axis is inclined at an angle to that of the outlet. A passage
extends through the head from inlet to outlet, and an
.,oscillator valve in the head is adapted to alternately open
and close said passage. A baffle plate is disposed in the
head between the inlet and. valve to form a restricted suction
connection between inlet and outlet around the valve when the
passage is closed. The flow of water causes the valve to
oscillate between its two terminal positions. In one
position, the flow is full and direct through the opening and
passage to the outlet. In the other position of the valve,
there is a maximum reduction in liquid flow through the head.
This results in an intermittent cut off flow through the head
as the valve oscillates between its terminal positions, and
4
2~90~.~5
this in turn causes pulsation which result in longitudinal
contractions and relaxations in the longitudinally resilient
suction pipe from the head to the outlet from the swimming
pool to its filter unit. In consequence of these contractions
and relaxations and a simultaneous reduction and increase of
the force applied to hold the cleaning head disc against the
surface to be cleaned, a step by step movement of the head
takes place over the surface to be cleaned.
The United States Patent No. 4,807,318 issued to Dieter
H.F. Kallenbach on February 28, 1989, Suction Operated
Cleaner, an automatic pool cleaner is disclosed which also
operates on the interruption of an induced flow of water
through the cleaner. The interruption in the flow of water
drawn through the pool cleaner is used to provide a propulsive
force to cause the cleaner to move over submerged pool
surfaces. The control of the interruption is effected through
a tubular axially resilient diaphragm one end of which is
closed and adapted to hold normally closed a passage from the
head of the pool cleaner to the usual form of flexible hose
connecting the pool cleaner to the filtration unit. The flow
of water through the pool cleaner causes a suction in a
passageway greater than that in a connection, the result being
that a spring and diaphragm force the closure of the
passageway. The intermittent interruption of flow through the
passageway and hose, and the simultaneous release of the force
5
2090.95
holding the cleaner and disc against the submerged surface
causes the cleaner to move in a stepwise manner over the
surface to be cleaned.
In addition to the mechanism used to move the cleaning
device along the submerged surface to be cleaned, various
appendages have been added to these devices to provide some
control over the cleaning pattern and for control of the
cleaner when encountering obstacles such as abrupt surface
changes and exiting the submersible fluid in which they were
designed to operate. The art of submersible pool cleaners has
been open to these various methods of automatically propelling
the cleaner over the surfaces to be cleaned because any one
brings inherent problems with its design.
In cleaning devices using shut off valves, the valve
intake tends to clog with larger debris and in order to
correct this condition, the cleaning device must be removed
from the pool and disassembled for cleaning. The membranes
used in these units have a tendency to break and require
replacement. The dramatic reduction of flow needed to create
the step by step movement of the cleaning device results in
severe changes in the pressure head at the suction pump thus
placing additional wear on this pump and motor. Cleaning
devices using turbine styled systems must depend on the high
speed movement of the turbine, large number of bearings and
the needed multitude of parts to convert the high speed to the
6
~0~01~
relatively slow cleaning movement. In addition, the many
bearing surfaces perform poorly after performance in the sand
which grinds down the bearing parts. The cleaning devices
relying on wheels for their traction encounter problems when
climbing the vertical walls of typical swimming pools. The
wheels slip in attempting to maneuver on the vertical wall and
will slip under certain conditions when climbing from the deep
end to the shallow end of the pool.
Many of the devices used tend to follow an established
pattern once placed into operation. This pattern, often a
figure eight style, tends therefore to avoid certain areas
over others that see the cleaner more often than necessary.
Finally, the onset of new plastics and fiberglass surfaces for
swimming pools has created the added demand on these devices
to be able to maneuver over slippery surfaces not before
encountered. The goal in the art is to find that device which
will cover the desired submerged surfaces, be able to execute
vertical walls, escape obstacles, avoid climbing out of the
submersible fluid where the sucking in of air will cause
damage and interrupt operation, place a minimum of excess
demand on the system suction pump and motor, and have as few
failing parts as possible.
7
2~1~0~~~
SDMMARY OF INVENTION
The present invention contemplates a self-propelled
suction cleaner used in conjunction with a pool suction pump
and motor for removing dirt and debris from the submerged
surfaces of the pool. It is also contemplated that the system
and method are useful in other environments. The cleaner is
connected at a coupling located on top of a housing. The
coupling is connected to the suction pump and motor using a
flexible elongated hose. The cleaner housing incorporates a
suction chamber located within the housing. The suction
chamber comprises an entrance end in proximity to the
submerged surface to be cleaned and an exit end communicating
with the coupling.
An oscillator is pivotably mounted within the suction
chamber. As the water flows past the oscillator, a to and fro
motion results. The shape and size of the chamber between the
oscillator and the coupling cause abrupt changes in water flow
and a continuous vibratory movement of the housing. The
housing has peripheral walls. A shoe is formed around the
periphery of the housing and adapted to engage the submerged
surface to be cleaned. The shoe comprises tread elements
which are angled in a forward direction with respect to the
surface. The element angles and the vibratory motion of the
housing cause the cleaner to advance in a random pattern over
the submerged surfaces including a vertical surface of the
8
2~90~95
pool. In preferred embodiments the elements of the shoe which
engage the surface take on elongated tracks parallel to each
other and perpendicular to the forward movement or can be a
plurality of finger elements with each element angled. In the
preferred embodiment, the angles range from a more
perpendicular angle in front of the housing shoe than in the
back with each track or element changing angle progressively
away from perpendicular as the elements go from front to back.
By making the coupling rotatable, the cleaner can be made
to turn at established intervals throughout the random path
and allow the cleaner to free itself from pool obstructions.
Means is provided for converting a reciprocal angular movement
or to and fro movement of the oscillator to an angular
movement in one direction for purposes of driving a shaft by
incorporating a ratchet and pawl assembly. A drive gear
essentially affixed to the shaft engages a gear train. The
gear train engages the rotatable coupling at defined intervals
to generate rotation of the coupling at these defined
intervals.
Means for limiting the elevation of the cleaner as it
climbs a vertical wall of the pool comprises a limiter member
affixed to and extending forward and out from the housing.
The member is dimensioned and disposed such that when the
upper end of the member breaks the surface of the water,
gravitational force diminishes any forward impetus of the
9
~0~01J~
housing and the extended member acting as a moment arm has the
effect of turning the cleaner back toward the water. By
affixing a hollow limiter member to the housing and having
openings in the hollow member communicating with openings in
the housing so as to~permit the water to fill the hollow
member, the relative weight of the cleaner while submerged
in the water is reduced making the to and fro motion of the
cleaner more effective in propelling the cleaner forward. Yet
the increased weight of the limiter member as it rises out of
the water due to the water contained within the limiter member
turns the cleaner back toward the water.
Debris can clog the suction chamber at the chamber
entrance end proximate to the surface being cleaned. To
prevent debris from reducing flow to a point~that creates
excess suction damaging to the pump and motor, the suction
chamber comprises a pressure relief valve. The pressure
relief valve comprises a by-pass opening in a housing wall
communicating with the suction chamber. A by-pass closure is
fitted over the by-pass opening and moveable between a closed
position in which the water is prevented from flowing through
the opening and an open position in which the water flows from
the by-pass opening and into the coupling on to the pump. The
by-pass closure is held closed using a spring biasing means
in the preferred embodiment. The opening in the housing wall
is a plurality of slots in the preferred embodiment.
l0
2~~0195
A gap is located between oscillator side walls and the
suction chamber walls. This gap should be as small as
possible for optimum flow through the chamber and resulting
optimum oscillator forces. AS the gap size increases, flow
through the gap inhibits oscillator vibration. Grit and
debris can fill the gap and impair oscillator movement. The
preferred embodiment comprises an oscillator having an
elongated groove along the edge of the oscillator and a
sealing strip extending into the groove and extensible across
the gap.
The present art includes a variety of suction cleaners.
A sample of the more typical suction cleaners using vibrator
valves, turbine assemblies, and wheels were described in the
background section of this specification. There are inherent
problems in each of these suction cleaners. Debris clogs
cleaners using vibrator valves and membranes to a point where
the membrane breaks and needs replacement or as a minimum the
cleaner requires disassembly before clearing and reassembly.
Turbine mechanisms have a high speed movement. The high speed
movement demands bearing surfaces and complex speed reducing
parts. The sand and grit found in a typical swimming pool
quickly wears the bearing surfaces and the sand generally
grinds down these parts. Wheeled cleaners have problems
climbing walls. The wheels slip when encountering the
vertical walls and the steep inclines running from the deep
11
20~90~.~~i
end of typical pools to the shallow end. The present cleaning
devices tend to slip on the contemporary surfaces made from
fiberglass and vinyl. Most of the cleaning devices require
smooth transition areas and can get hung up on a step as an
example. Many cleaners form a pattern within the pool which
is not efficient for cleaning all surfaces. The shut off
valve styled cleaners use a stepping motion to propel the
cleaner forward that intermittently and dramatically cuts the
flow and induces high suction and pressure causing excess
strain for the pump and motor.
It is the object of the disclosed invention to avoid the
problems inherent in the designs described and provide a self-
propelled suction cleaner using continuous suction flow
through the cleaner and this continuous flow to provide the
I5 vibrating motion needed to advance the cleaner forward. The
invention provides means for limiting the elevation of the
cleaner above the water line of the pool and thus prevent the
pump from sucking unwanted air. The random pattern of the
cleaner as it advances over the pool surface is enhanced by
a turning means that prevents the cleaner from becoming hung
up at obstacles such as pool steps and abrupt surface changes.
Should debris clog the cleaner suction chamber, a pressure
relief valve will be activated and will eliminate excess
strain on the pump and motor.
12
~UJU195
During operation of the preferred embodiment, nominal
pressures ranging between 10 kPa were measured at a position
proximate to the weir in a pool cleaning system. Open hose
pressures were measured at approximately 8 kPa. In contrast,
devices relying on flow cut off to initiate movement generate
nominal pressures ranging from 22 kPa to 30 kPa when measured
at the same weir position. (1 kPa equals 1000 Pascal units,
a metric measure of pressure. one pound per square inch is
equivalent to 6.89 kPa units.)
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the invention including
alternate elements is described by way of example with
reference to the accompanying drawings in which:
FIG. 1 is a side view of the preferred embodiment for the
self-propelled submersible cleaner;
FIG. 2 is a bottom view of the cleaner housing shown with
shoe removed;
FIG. 3 is a partial cross-sectional side view of the
suction chamber illustrating the arrangement of the oscillator
and buffer formations;
FIG. 4 is a bottom view of a shoe having elongated track
elements, the skirt elements are displayed;
FIG. 5 is a perspective view of an oscillator used in the
preferred embodiment;
13
~U~U~J~i
FIG. 5a (side view) and FIG. 5b (bottom view) show
alternate embodiments for the oscillator and seal arrangement;
FIG. 6 is a partial cut-away view of a section of the
oscillator showing the seal arrangement;
FIG. 7 shows an alternate embodiment of a split
oscillator in perspective view;
FIG. 8 is a bottom view of another embodiment using
moveable suction chamber side walls;
FIG. 9 is a perspective view of the cleaner from the rear
showing the rear skirt and pressure relief valve apertures;
FIG. 10 is a bottom view of a shoe tread incorporating
finger elements, skirt elements are shown;
FIG. 11 is a partial cut-away view of the cleaner housing
showing one embodiment of a pressure relief valve using leaf
springs;
FIG. 12 is a coil spring version of the pressure relief
valve in a partial cross-sectional view;
FIG. 13 is a partial cross-sectional view of the pressure
relief valve in the preferred embodiment;
FIG. 14 is a perspective view of the drive mechanism
showing the sprag, pawl and ratchet assemblies;
FIG. 15 is a partial cross-sectional view of the drive
mechanism, sprags shown in a latched state;
FIG. 16 is a second partial cross-sectional view of the
drive mechanism showing the sprags in a freed state;
14
~~~~~~:1 ~~~
FTG. 17 is a partial crass sectional view of the drive
mechanism communicating with the oscillator;
FIG. 18 is a partial cross-sectional view of the gear
train and rotatable coupling engagement;
FIG. 19 is a partial top view showing the interval drive
teeth of the interval drive gear engaging the translational
intermediate gear, the translational intermediate gear engages
the coupling gear;
FIG. 20 is a partial front view of the interval drive
gear engaging a reducing intermediate gear;
FIG. 21 is a partial view showing driven gear engaging
the reduction gears in relation to the oscillator:
FIG. 22 is a partial top view showing the rotatable
coupling, coupling gear being engaged by the interval drive
gear through the translational intermediate gear;
FIG. 23 is a perspective exploded view of the friction
gear assembly;
FIG. 24 is a partial perspective view of the ratchet and
pawl mechanism used to engage the drum; and
FIG. 25 is a partial cross-sectional view of the friction
drive mechanism com~~nunicating with the oscillator.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
The preferred embodiment of the invention, a self-
propelled submersible suction cleaner to particularly
~~~~~~.~.J~
describes a swimming pool cleaner 10 which makes use of the
flow of water through a cleaner housing 12. This embodiment
is generally described in FIG ~. through FIG 4 of the enclosed
drawings. The housing 12 contains a suction chamber 14 having
a mouth 16 located at an entrance end 18 in which water flows.
The chamber exit end 24 communicates with a coupling 26
located on top of the housing 12. In the preferred
embodiment, the coupling is rotatable. The propulsion
mechanism for the cleaner 10 includes an oscillator 20
pivotally mounted to side walls 22 of the chamber 14. The
oscillator 20 is disposed within the flow path of the water
through the suction chamber 14. The flow is caused by
connecting the suction chamber 14 to a filter pump and motor
by a suitable flexible hose as is typically done in the pool
cleaning art. The hose is connected at the coupling 26. The
oscillator 20 is so shaped that flow therepast causes it to
move to and fro about its pivot point and impact the forward
28 and aft 30 walls of the chamber 14 to create a vibratory
movement of the chamber 14 and housing 12 to which the chamber
I4 is an integral part. This vibratory movement acting on the
housing 12 causes a shoe 32 attached at the periphery 34 of
the housing 12 and in contact with the pool submerged surface
36 to vibrate. The shoe 32 has tread elements 38 contacting
the submerged surface 36 at an angle 40. This angle 40 is
such to drive the housing 12 in a forward direction and thus
16
.-
2n~lU~~S
propel the cleaner 10 over the submerged surface 36 of the
pool.
The cleaner 10 being propelled in this forward direction
42 (illustrated in FIG. 1) would typically take a somewhat
random path determined by the pool surface contours peculiar
to any given swimming pool. To improve on the randomness of
the path and avoid developing a path pattern, the preferred
embodiment of this invention incorporates a turning mechanism
200 using a rotatable coupling 26 and means for converting the
vibratory motion to a rotating motion for turning the cleaner
10 at intervals through at least a 90° turn. Such a turn
during the random path will insure that the path does not
establish a pattern, typically a figure eight in many swimming
pools. In addition, should the cleaner 10 encounter an
obstacle such as a step, typically found in swimming pools,
the 90° or greater turn will permit the cleaner to maneuver
away from the step.
The cleaner 10 will climb the submerged vertical wall of
the swimming pool and reach the surface of the water. Noting
FIG. 1 and FIG. 9, the preferred embodiment includes an
elevation limiter 100 which turns the cleaner back toward the
water as it attempts to climb out. This limiter 100 allows
the suction chamber 14 to always see a flow of water and
avoids the detrimental sucking of air by the pump.
17
~U~IU.~~~~
The suction chamber 14 is configured to accept the sand
and even larger debris such as leaves typically found in
swimming pools and not clog. However, should the suction
chamber clog up and severely increase pressure in the chamber
14 and to the pump, a pressure relief valve 300 is a part of
the preferred embodiment. The following further describes
the invention with additional detailed descriptions of the
elements making up the preferred embodiment of the cleaner l0
and alternative embodiments for some of these elements.
The Oscillator 20 and suction chamber 14 can be further
described as follows:
In order for the oscillator 20 to operate efficiently it
must be located in a suction chamber 14 so that the oscillator
pivots in close proximity to side walls 22 of the chamber
15 14. This is necessary so that the bulk of flow past the
oscillator 20 moves along surfaces designed to provide the to
and fro movement of the oscillator.
The suction chamber located within the housing 12 is
comprised of side walls 22, forward wall 28 and aft wall 30,
20 the forward and aft walls defined by the housing 12 in the
preferred embodiment as illustrated in FIG. 2 and FIG. 3.
The oscillator 20 (shown in FIG. 3 and FIG. 5) is
pivotally mounted within the suction chamber on a hinge pin
92 extending through a boss 44 on the oscillator, the hinge
pin being journalled on the side walls 22.
18
~~~~~~~a
As illustrated in FIG. 3, the liquid flow 90 into the
suction chamber 14 via the mouth 16 of the housing impinges
on the oscillator 20 flowing around the edges 46 causing the
oscillator 20 to swing to and fro on its hinge pin 92
impacting against the chamber forward 28 and aft 30 walls.
Buffer formations 70 are placed between the edges 46 of the
oscillator 20 and chamber walls. In addition the flow has an
abrupt change at the top of the chamber as the flow 90 moves
past the oscillator 20 toward the chamber exit and coupling
26.
It will be appreciated that the efficiency of the
operation of the oscillator 20 depends on the strength of flow
over the oscillator edges 46. If this flow is dissipated
around the side edges 48 and 50 of the oscillator between the
latter and the chamber side walls 22, the strength of the flow
past the oscillator edge 46 will be diminished with a
consequent drop in the efficiency of the propelling action of
the oscillator.
In order to prevent such dissipation of the flow energy,
the arrangement may be one in which the oscillator 20 is
neatly located between the chamber side walls 22 so that
little flow is dissipated. In this event, however, grit drawn
into the suction chamber 14 is liable to lodge between the
oscillator 20 and side walls 22 thereby causing loss of
19
2~Q0.1~~
efficiency of the oscillator 20 through friction, or the
oscillator 2o may even stick.
In accordance with the present invention the oscillator
20 (shown in FIG. 5) and suction chamber 14 are designed so
that the edges 48 and 5o are suitably spaced from the side
walls 22 of the suction chamber 14 to enable grit to pass
easily therethrough. Retractable elongated seals 54 are
provided at each edge of the oscillator 20 to seal the gap 52
between the edges 48 and 50 of the oscillator 20 and the side
walls 22 of the suction chamber (shown in FIG. 6).
Elongated seals 54 (FIGS. 5 and 6) are located in slot
56 in the respective edges 48 and 5A of the oscillator 20, the
width of the strips being no greater than the depth of the
slots 56.
In an alternate embodiment (illustrated in FIGS. 5a and
5b) for the oscillator 20, seals 54a are contoured to the
oscillator 20 and have their ends 54b riding in slots 56a
located at the oscillator edges 46 (as shown in FIGS. 5a and
5b). Slide bars 54c are affixed to the seals 54a to provide
a means for sliding the seals 54a back and forth so as to
dislodge grit during a cleaning process for the cleaner l0.
Thus when the suction chamber 14 is coupled to a filter pump
and water is caused to flow around the oscillator 20 in the
suction chamber 14, the seals 54 are drawn outwardly from the
slots 56 into sealing engagement with the chamber side walls
~~~~:~~u
22 of the suction chamber 14. Under normal operation of the
oscillator 20 the engagement between the elongated seals 54
and the chamber side walls 22 causes minimal friction and
little impairment of the efficiency of the oscillator 20. In
the event that grit finds its way between a seal 54 and the
side walls 22, the seal 54 is simply forced to retract into
the slots 56 allowing the grit easily to pass through the
suction chamber 14 and into the filter system of the swimming
pool.
Referring now to FIG. 7, it will be seen that in an
alternative arrangement the oscillator 20 is split into two
sections 20a and 20b. The oscillator sections 20a and 2ob
have a groove 60. A tongue 58 is slidable into and out of the
groove 60.
In the event that grit finds its way between the seal
sides 48 and 50 and the chamber side walls 22, the oscillator
sections 20a and 2ob are simply forced to retract along the
tongue 58 and into the groove s0 of oscillator sections 20a
and 20b thereby opening a gap between elongated seals 54 and
side chamber walls 22 of the suction chamber 14 and thus
allowing the grit easily to pass through the suction chamber
14 into the pool system filter.
Referring now to FIG. 8, a second alternative is provided
in the form of a suction chamber 14 having side walls 62 and
64 mounted so as to allow end sections 62a and 62b and 64a and
21
209~~. ~9
64b to be slidable into and out of guide tracks 66a, 66b and
6sa, 68b, respectively.
Under normal conditions the side walls 62 and 64 are
drawn against the oscillator 20 by the suction created within
the suction chamber 14. However. should grit enter hetwPP"
the oscillator 20 and the walls 62 and 64 the latter simply
retract into the guide tracks 66a, 66b and 68a, 68b allowing
the grit to pass through the suction chamber into the pool
filter system.
Because of the strength and frequency of the impact on
the forward 28 and aft 30 chamber walls by the oscillator,
buffer formations 70 are affixed to the chamber wall 28 and
30 at the impact location between the impacting oscillator
edge 46 and chamber wall. In the preferred embodiment these
buffer formations 70 are rubber-like pads. These buffer
formations thus protect the housing 12 and in general the
cleaner 10 from damage resulting from the action of the
oscillator.
The hoe 32 assembly 32 can be further described as
follows:
As disclosed earlier and in FIG 3 & 4, the shoe 32
comprises a plurality of tread elements 38. The tread
elements 38 can be in the form of elongated tracks 72 as shown
in the preferred embodiment of FIG 4 having the track elements
72 spaced and generally parallel to each other with the
22
~~~n~~~
elongated element perpendicular to the forward direction 42
of the cleaner movement. The elements 72 are angled forward
with respect to the submerged surface. In the preferred
embodiment shown in FIG 3, the elements 72 form an acute angle
40 with respect to a perpendicular to the shoe. As the
elements progress from the front of the housing 74 to the rear
the angle 40 increases progressively for each respective
element 72. 'The first few rows of elements 72 at the front
74 are shorter than in the middle or rear in order to better
execute the climbing of a steep vertical pool wall.
In addition to this climbing feature in the preferred
embodiment, a coupling bellows 78 is fitted to the coupling
26. This bellows 78 provides added flexibility to the end of
the flexible hose and permits improved execution of the steep
vertical pool wall. FIG 1 discloses this coupling bellows
78 configuration.
In an alternate arrangement, the shoe 32 is configured
with tread elements 38 that are made from a plurality of
finger elements 8o set in a matrix array as described in FIG
10. The matrix is made from parallel rows of finger elements
80 spaced in a similar manner as the parallel rows of track
elements 72. Each row of finger elements 80 is angled and
configured as the track elements 72 with a tread element angle
40 and progression of increasing angles when moving from front
to back as described earlier.
23
is7~.. ..
7..
The outside portion of the shoe 32 making contact with
the surface has an outside dimension defined by the housing
periphery 34 and an inside dimension to provide sufficient
contact with the surface to be cleaned and an opening to allow
access to the mouth 16. The tread elements 38, whether finger
elements 80 or track elements 72, define a shoe removably
affixed to the housing periphery passing partially around the
mouth 16 of the suction chamber 14. A flap 82 (illustrated
in FIG. 4 and FTG. 9) is pivotally affixed to the housing
periphery directly behind the suction chamber aft wall 30.
In an alternate embodiment, the flap is made an integral part
of the shoe which shoe then passes completely around the mouth
16. The flap 82 is a means for flow adjustment and control
by pivoting open and closed during variations in suction. In
addition to the flap 82, an internal skirt 84 (refer to FIG.
4 and FIG. 10) and external skirt 86 are positioned near the
periphery and prevent the free flow of water through the shoe
elements thus causing the suction to increase. The skirts can
be made a part of the shoe elements or a part of the housing.
In the preferred embodiment, both methods are incorporated.
An internal skirt portion 88 is comprised of an extension of
the forward chamber wall. The balance of the internal skirt
84 is a part of the shoe as is the external skirt 86. The
height of both skirts is slightly shorter than the tread
24
~~9~.~~~
elements 38 to permit the elements 38 to flex during their
vibratory and propelling movement.
The skirts project downwardly as described. In a
preferred embodiment the external skirt 86 is configured such
that the tread elements 38 are almost fully exposed at the
front of the housing 12 but project only slightly beyond skirt
at the rear of the housing as illustrated in FIG. 9.
The internal skirt portion 84 can be molded integrally
with the housing 12 and be located adjacent the elements and
internally thereof and extends from one side of the suction
chamber 14 the other along the front thereof. Both the
external skirt 84 and internal skirt 88 are also laterally
spaced from elements so that the elements are able to flex
under the vibratory action of the oscillator 20.
It will be appreciated that the flow of water into the
suction chamber 14 is directed around the free edges of the
internal 84 and external skirts 86 in order to provide
sufficient suction through the suction chamber 14 on a
submerged surface engaged by the cleaner lo.
As an additional note, it is a feature of the invention
that the leading edge of the oblong shape of the shoe is a
straight edge disposed substantially at right angles to the
direction of movement of the cleaner lo. Preferably the rear
edge will likewise is a straight edge as shown in FIG. 2. It
has been found that the straight, front and rear edges of the
i
2c~9~.~.~5
shoe 32 and tread elements 38 enhance the mobility and
climbing ability of the cleaner.
As discussed, it has been found that the differential
angle of the elements (illustrated in FIG. 1) in the leading
and trailing edges, enhances the climbing ability of a
cleaning device through an upwardly radiased curved surface,
the climbing ability of the suction cleaning is further
enhanced by the straight leading and trailing edges of the
skirt formation.
The elevation limiter 100 can further be described as
follows
The housing 12 includes a limiter member 110 which for
the preferred embodiment comprises an inverted U-shaped pipe
connected at its ends to the housing 12 towards the sides
thereof so that the open ends 112 of the pipe communicate with
the housing 12.
As illustrated in FIG. 1 and FIG. 2, the member 110
extends upwardly and forwardly with respect to the housing 12
and when the latter is immersed in a pool the member 110 fills
with water.
With forward motions of the cleaner to up the side wall
of a pool, the cleaner rises until the upper end of the member
110 breaks the surface of the water whilst the suction chamber
14 of the housing 12 is still located just below the surface.
As the member 110 emerges from the surface of the water it
26
2~9~~.~~
undergoes an apparent gain in weight and the upward and
forward extent of~the member 110 and its dimensions are
designed so that the gain in weight balances the forward
impetus of the head when the latter is just beneath the
surface. In this way the member 110 operates as an elevation-
limiting device preventing the suction chamber 14 from
breaking the surface of the water and drawing in air which
would impair the operation of the pump.
By adding a flexible portion to the extension member 110
proximate to the housing 12, the vibratory motion of the
housing 12 causes the extended limiter member 110 to flex.
This flexing reduces the resistance created by the movement
of the member 110 through the water, thereby allowing freer
vibration and thus efficient operation of the cleaner 10. In
the preferred embodiment, bellows couplings 114 are affixed
to the limiter member 110. The flexible nature of the bellows
114 provides a sufficiently reduced moment arm and provides
the smoother forward movement for the cleaner 10.
The turning mechanism 200 can further be described as
follows:
In order to more clearly illustrate the invention, an
embodiment for a drive mechanism is described hereunder with
reference to the accompanying drawings of FIGS. 14 through 18.
A drive mechanism 210 illustrated in FIG. 14 through FIG.
17) is used with the submersible cleaner 10 for translating
27
2~90~.va
reciprocating angular movement 212 of a drive shaft 214 into
one directional angular movement 216 of a driven gear 218.
The driven gear 218 can perform a number of functions for the
pool cleaner and it is in particular envisaged that it will
drive a gear train 220 mechanism for a pool cleaner through
a number of reduction gears 222, such as that shown in FIG.
18 and used to turn a rotatable coupling gear 254 and thus the
coupling 26.
The drive mechanism comprises a peripheral ring 226 of
teeth 228 secured or integrally formed within a drum 230
defined at the end of the driven gear 218. The teeth are
periodically engaged by a plurality of pawl or sprag elements
232 which are pivotally mounted in pockets 234 defined in a
collar formation 236 at the end of the drive shaft 214. The
collar 236 of the drive shaft 214 and the sprag elements 232
are thus disposed within the drum 230 of the driven gear 218
to enable the sprag elements 232 periodically to engage the
internal teeth 228.
The pockets 234 which pivotally mount the sprag elements
232 define opposed abutment surfaces 234a, 234b, which act to
limit pivotal movement of the sprag elements 232 between a
first extreme position (shown in FIG. 15) wherein the sprag
elements 232 are substantially radially disposed to engage the
teeth 228; and a second extreme position (shown in FIG. 16)
28
2~9U~.~
wherein the sprag elements 232 are angled relative to the
radial and out of engagement with the teeth 228.
It is a feature of the invention that the sprag elements
232 operate in a liquid medium, such as water, preferably the
same liquid in which the surface to be cleaned is immersed,
and this medium tends to impart a high degree of inertia to
the sprag elements 232. The free ends 232a of the sprag
elements 232 thus tend to remain stationary during angular
movement of the drive shaft 214 in one direction or the other.
Thus, with the sprag elements 232 in the first extreme
position and radially orientated (FIG. 15), rotational
movement of the drive shaft 214, for example, in an anti-
clockwise direction causes the sprag elements 232 to move to
the second extreme position (FIG. 16) and remain in such
position during further anti-clockwise rotation of the drive
shaft 214. Likewise, when the shaft 214 reverses its
direction of rotation to a clockwise direction, the sprag
elements 232 will immediately straighten out to the first
extreme position wherein they are radially oriented and engage
the teeth 228 of the driven gear 218.
In order to permit rotational movement of the driven gear
218 to one directional movement, the invention further
provides a pawl 240 and ratchet 242 arrangement comprising
peripheral ratchet teeth 242 defined on the outer periphery
29
2~D~ f11~5
of the drum 230 which are engaged by means of the pawl 240
which is mounted independently of the drum 230.
The driven gear 218 will rotate during the movement of
the cleaner 1o through the described translation of
reciprocating angular movement 212 into one direction angular
movement or rotation. This rotating driven gear 218 can be
coupled with a variety of drive mechanisms including a
mechanism to lift the suction chamber to break suction, and
drop the cleaner off a vertical wall as an alternative
embodiment for the elevation limiter 200 discussed earlier.
In the preferred embodiment, the driven gear 218 is used
in conjunction with a gear train 220 (described in FIGS. 18
through 22) that engages a coupling gear 254 engaged with the
coupling 26. The driven gear 218 engages a first gear 244 and
a series of reduction gears 222 to engage an interval drive
gear 248. The interval drive gear 248 contains a set of
interval teeth 250 that engage the coupling gear 254 through
a translational intermediate gear 252. Sufficient teeth 250
are placed on the interval drive gear 248 to allow the
coupling 26 to rotate through at least a 90° turn.
In an alternate embodiment of the drive mechanism (FIG.
23 through FIG. 25), a friction drive is adapted to translate
oscillating angular movement of a drive shaft 214 into
periodic one directional angular movement of a driven gear
20019
218. The driven gear 218 can then drive further gears as
earlier described to cause the rotation of the cleaner l0.
The friction drive illustrated in FIG. 23 through 25
comprises a first friction surface 260 defined by a disc
element 262, to which the drive shaft 214 is secured or with
which it is integrally formed. The friction disc 262 is urged
into contact with a second friction surface 264 defined by a
second disc 266, by means of a compression spring 268 and the
second friction disc 266 is in turn associated with a driven
gear 218. The second friction disc 266 is secured to a drum
formation 236 to which the driven gear 218 is secured or with
' which it is integrally formed so that rotational movement of
the friction disc 266 causes rotational movement of the gear
218.
In an alternative arrangement (not shown), the driven
gear 218 is secured to a friction disc such as that shown at
262 which is urged into frictional engagement with a friction
surface defined by the interior blind face 268 of the drum
formation 236, with the drive shaft 214 secured directly to
the drum 236 or to the friction disc 262.
In the embodiment illustrated, the friction disc 262 is
induced into frictional engagement with the friction surfaces
264 by means of a compression spring 268 which terminates in
washers 270 and 272.
31
~~3~~.~~5
In order to limit movement of the driven gear 218 to one
directional movement as shown by the arrow 216; a pawl 240 and
ratchet 242 arrangement is also provided, with teeth of the
ratchet 242 being defined on the outer surface of the drum
236. With reference to FIG. 24, a pawl 240 in the form of a
resilient leaf spring 240 is provided to engage the teeth 242
to prevent reverse rotation of the drum 236 and thus the
driven shaft 218.
The pressure relief valve 300 is further described as
follows:
The housing 12 incorporated a suction chamber 14
comprised of side walls 22 and end walls 28 and 3o defined by
the housing itself.
The coupling 26 is provided on the housing 12 for a
suction hose (not shown) used to connect the suction head to
the filter pump of a swimming pool. Coupling the housing 12
and chamber 14 to the filter pump causes flow into the suction
chamber 14 via the mouth 16 and the flow impinges first on one
edge 46 and then on the other edge 46 of the oscillator 20
causing the latter to swing to and fro.
It will be appreciated that if large objects such as
leaves, twigs and the like, collect in restricted areas of the
flowpath past the oscillator 20, the flow path could become
starved and if no relief or by-pass valve is provided, the
motor driving the pump will be damaged.
32
2~~0~~5
In accordance with the present invention the housing 12
includes by-pass apertures 310 in the suction chamber 14 at
the upper end thereof close to coupling 26 for the suction
. hoses. These by-pass apertures 310 are closed off by a by
pass closure 312 pivotally mounted within suction chamber 14
on hinge pin 314. Leaf springs 316 are secured at their ends
316a on to the housing 12 within the suction chamber 14 and
at their opposite ends 316b to the by-pass closure 312. Thus
the leaf springs 316 bias the closure 312 to a position
closing the by-pass apertures 310. FIG. 11 describes this
embodiment.
With normal operation of the suction cleaner device the
restricted passages in the location of the oscillator 20 are
unblocked and the springs 316 exert sufficient force to
maintain the closure 312 in a closed position. However,
should the entrance to the suction chamber become blocked with
leaves or other debris, the pressure in the suction chamber
14 will drop abnormally through the action of the filter pump
causing the closure 312 to be forced away from the by-pass
apertures 31o against the biasing action of springs 316.
Water will thus flow into the suction chamber 14 and the
suction hose via the by-pass apertures 310 until the blockage
of the suction chamber is removed. In this way by-pass
apertures 310 act as a pressure relief valve 30o ensuring that
the pump is not starved and that its motor is not endangered.
33
20~~~.~.~
It will be appreciated that the positioning of the by-pass
apertures 310 downstream from the oscillator but away from the
pool system weir render it unlikely that the apertures 310
will become blocked. Furthermore it eliminates air suction
at the weir when the water level is low.
In addition, the strength of springs 316 is balanced to
ensure that water is drawn in via the by-pass valve in a
controlled way providing an additional means for regulating
the speed of the oscillator and thus the suction at the
suction chamber mouth 16.
In a similar manner (illustrated in FIG. 12), coil
springs 320 can be used to hold the by-pass closure 312
against the by-pass apertures 310. In a third and preferred
embodiment, the by-pass apertures 310 are closed using a
flexible plate 322 biased against the apertures 310 by
affixing one end of the plate 322a to the chamber wall
adjacent the apertures as described in FIG. 13.
This concludes the description of the preferred
embodiments. A reading by those skilled in the art will bring
to mind various changes without departing from the spirit and
scope of the invention. It is intended, however, that the
invention only be limited by the following appended claims.
34
