Low pressure automatic swimming pool cleaner

A pool cleaner operating with a pool cleaning system which is not equipped with a booster pump. The apparatus may comprise a frame having a forward end and a rearward end with a water inlet mounted on the frame and receiving a supply of water having a volume per unit time. The inlet may comprise a supply mast having a number of openings for supplying water to the various components of the cleaner. The frame is carried on a plurality of transport wheels mounted on the frame. The apparatus further includes a vacuum system including a collection bag positioned on a suction mast having water injection ports positioned such that at least one opening in the water injection port injects water into the collection bag to create suction and draw debris into the bag. A drive system is provided to move the apparatus around the pool. The drive system includes a turbine having a plurality of vanes rotating and mounted in a turbine housing. The turbine housing has a first water input and a second water input each oriented to allow a stream of water passing therethrough to impact an individual vane at the same angle of incidence as the vane passes through the stream. A drive axle couples to the turbine and at least one of the plurality of transport wheels. In a further aspect the drive system may include thruster jets positioned on the mast adjacent to the rearward end of the frame.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to the field of automatic swimming pool 
cleaners, and more particularly, to cleaners of the type for submerged and 
generally random travel along the floor and sidewalls of a swimming pool 
to dislodge and collect debris. 
2. Description of the Related Art 
A swimming pool normally includes a water filtration system for removing 
dirt and debris from the pool water. Such filtration systems typically 
include a circulation pump which is installed outside the swimming pool 
and a piping system for coupling the circulation pump to the swimming 
pool. The circulation pump draws water from the swimming pool for delivery 
through the piping system to a filter unit. 
One or more baskets are located in the piping system upstream from the 
filter unit to catch larger debris, such as leaves and the like; the 
filter unit functions to separate dirt and fine debris from the water. The 
water is then re-circulated by the pump back to the swimming pool. 
A conventional water filtration system is satisfactory for removing dirt 
and debris of a relatively small size that is suspended in the water, but 
it is not designed to remove larger debris. Such systems depend on the 
aforementioned baskets to prevent larger debris from reaching the filter. 
However, it is generally advisable to clean out such baskets regularly to 
avoid the possibility that they may become clogged, blocking the flow of 
water through the pipes and resulting in damage to the circulation pump. 
Moreover, a conventional water filtration system is not designed to remove 
silt and debris which tends to settle irrespective of size onto the floor 
and sidewalls of a swimming pool. 
To address the foregoing problems, automatic swimming pool cleaners for 
cleaning the floor and sidewalls of a swimming pool are well known. 
There are generally four types of pool cleaners in the pool cleaning 
market: pressure or return side cleaners; suction cleaners; electric 
cleaners and in-floor cleaners. 
Suction side cleaners connect to the pool's skimmer and utilize the sucking 
action of the water being drawn from the pool by the filter pump to vacuum 
debris. These cleaners do not sweep, nor to they employ a collection bag, 
as demonstrated by U.S. Pat. No. 5,001,600 (Parenti, et al.). Instead, 
large debris vacuumed by the suction side cleaners is deposited in the 
skimmer or pump basket, while sand and silt that is small enough to pass 
through the skimmer is captured in the pool's filter. 
In-floor cleaners comprise pop-up sprinkler heads built into the floor of 
the pool and are not generally competitive with pressure, suction or 
electric sweep cleaners. 
Electric cleaners include an electrical motor and attach to an electric 
cord that extends into the swimming pool. These cleaners operate much like 
a household vacuum cleaner and may include a filter or collection bag to 
collect debris. However, the sweeping action of electric cleaners is 
limited to a roller or brush positioned under the cleaner and the cleaner 
does not act as roving return lines for chemically treated or heated pool 
water. Because they are very costly, they have never been a significant 
factor in the residential in-ground pool cleaner market. 
Generally, "pressure" or return-side cleaners perform superior cleaning 
over the other three types of cleaners because: Pressure cleaners both 
vacuum and sweep; Pressure cleaners act as a roving return line to 
circulate pool chemicals and heated water throughout the pool; Pressure 
cleaners to not interfere with pool skimmer operation; and Pressure 
cleaner have a collection bag to avoid the risk of clogging the pool's 
skimmer or pump basket and filter with debris. 
One significant difference in such types of cleaners is the use of a debris 
bag in the pressure-type cleaners. Pressure-type cleaners use pressurized 
water from a pump into the cleaner to sweep and collect debris into a bag 
carried by the cleaner. This means that the bag itself has a weight, 
buoyancy, and a weight factor that changes when debris collects in the 
bag. The cleaner must be able to traverse the entire pool without being 
toppled. Weight is added to the bag when debris is collected in the bag, 
changing the weight of the bag as the cleaner moves in the pool. 
In a pressure cleaner, the influx of water into the cleaner affects the 
manner in which the cleaner acts under water. The buoyancy of objects is 
also a significant consideration in developing pressure cleaners and is 
affected by the component in the cleaner and the water inflow and action 
of the water within the cleaner. These considerations are not present in 
electric cleaners or suction cleaners. 
Pressurized cleaners can be characterized into at least two 
categories--those requiring a booster pump and those which do not. Booster 
pumps are used in conjunction with the pools skimmer pump to provide 
pressurized water to the cleaner at a rate sufficient to operate the 
cleaner effectively. 
One particular type of known automatic pressure cleaner is shown and 
described in U.S. Pat. Nos. 3,822,754, 3,936,899, and 4,558,479. This type 
of cleaner has three wheels positioned in a skewed triangular arrangement 
on the outside of a housing, with the housing having a front nose set 
angularly with respect to the direction of cleaner movement. An open and 
generally vertically oriented suction mast defines a flow path through the 
housing with a collection bag mounted at the upper end. 
This type of cleaner operates on pressurized water that is supplied to the 
cleaner through a supply hose. The water is used in part to drive the 
blades of a turbine which, in turn, rotates two or more of the wheels, and 
in part to induce a flow of pool water upwardly through the suction mast 
and into the collection bag. A portion of the pressurized water is also 
supplied through a sweep hose jet to a sweep hose and through a thrust 
jet, both at the rear of the cleaner. A booster pump may be used to 
generate added water pressure for the cleaner, because the circulation 
pump normally used in most swimming pool filtration systems does not 
create sufficient water pressure for all of the above purposes. 
In operation of this type of cleaner, the drive wheels and thrust jet 
propel the cleaner along the floor and sidewalls of the swimming pool. 
When the pool cleaner reaches an obstruction preventing further direct 
forward travel, the skewed drive wheels and angled front nose of the 
cleaner housing imparts a turning movement, causing the cleaner to turn 
and continue travel in a different direction. Alternatively, when the 
cleaner travels along the pool floor and reaches a smoothly curved region 
merging with a sidewall, the cleaner tends to travel through the curved 
region and crawl at least part way up the pool sidewall with 
suction-assisted wheel traction until the cleaner falls by gravity back to 
the floor of the pool. A ballast float mounted at the upper rear of the 
cleaner helps assure that the cleaner will land upright on the pool floor 
and resume travel in a forward direction. As the cleaner travels around 
the pool, it vacuums the larger debris up through the suction mast into 
the collection bag. At the same time, the whipping action of the sweep 
hose sweeps any silt and smaller debris into suspension so that it can be 
filtered out by the pool's filtration system. 
While submerged pool cleaning devices of the foregoing type have performed 
in a generally satisfactory manner, certain shortcomings have been 
observed in available commercial equipment. For example, existing cleaners 
have been constructed on the premise that it is advantageous for all three 
wheels to be driven by the turbine. In order to accomplish this, however, 
the cleaner uses a drive train for the wheels which either has been partly 
exposed to potential jamming or damaged from contact with pool debris, or 
has used internal belts that have not proved highly reliable. In addition, 
existing cleaners have not typically been capable in practice of climbing 
the sidewalls of a swimming pool as aggressively as desired. For example, 
instead of the cleaner turning when it reaches a relatively sharp 
transition between the pool floor and a sidewall, it would be desirable 
for the cleaner to continue its forward travel and climb the sidewall. 
Further, it would be desirable for the cleaner to climb the sidewall 
nearly all the way to the waterline. 
In addition, cleaners of the type listed in the '479 patent have required a 
booster pump be installed in order to generate sufficient pressure to the 
apparatus to power the device about the pool. In older pool installations, 
the pool's cleaning system may require retrofitting to install the booster 
pumps in order to properly operate the device. 
Accordingly, a need exists for an improved automatic swimming pool cleaner 
of the type adapted for submerged travel over pool surfaces operating 
effectively without a booster pump. The present invention fulfills these 
and other needs. 
SUMMARY OF THE INVENTION 
Briefly, and in general terms, the present invention resides in a novel and 
improved design for an automatic swimming pool cleaner of the type for 
submerged and generally random travel along the floor and sidewalls of a 
swimming pool to dislodge and collect debris. In particular, the cleaner 
includes improved wheel and drive train arrangements and other features 
that result in enhanced climbing ability with a highly reliable drive 
train having virtually no exposure to potential jamming or damage from 
debris. 
In one aspect, the pool cleaner of the present invention comprises a frame 
which is carried by a plurality of wheels and on which is mounted a 
housing with a turbine, water supply means for receiving a supply of water 
through a supply hose, and a vacuum system comprising a suction mast 
defining an open flow path from a lower end positioned generally beneath 
the housing to an upper end disposed generally above the housing, with 
means for inducing a water flow adjacent the submerged surfaces of the 
swimming pool for drawing debris from within the pool into a collection 
bag mounted at the upper end of the suction mast. 
Significantly, in accordance with a primary aspect of the present 
invention, the wheels for the cleaner include first and second wheels 
which are mounted on opposite sides of the housing for rotation about a 
common axis. A drive system is provided to couple the turbine to both the 
first and second wheels for driving rotation to propel the cleaner in a 
forward direction along the submerged surfaces of the swimming pool. The 
first and second wheels are sized and positioned such that they extend 
beyond the forward end of the frame and of the housing. When the first and 
second wheels engage a relatively sharp transition between the pool floor 
and a sidewall, the cleaner tends to continue its forward travel and 
climbs the sidewall, rather than turning and heading off in a different 
direction along the pool floor. 
In a further aspect of the invention, the first and second wheels are 
mounted forwardly of the suction mast, thereby providing the cleaner with 
front wheel drive. The turbine may be drivingly coupled to the first and 
second wheels by means of gears that mesh with wheel gear. 
Third and fourth wheels are also mounted on opposite sides of the housing 
rearwardly of the suction mast. The third and fourth wheels also may be 
mounted for rotation about a common axis, similar to the first and second 
wheels. 
In a further aspect of the present invention, a forward end of an upper 
surface of the housing is provided with a sloping portion to impart a 
downward force at the forward end of the cleaner to reduce its tendency to 
lift off the submerged surfaces of the swimming pool as the first and 
second wheels propel the cleaner in the forward direction. The sloping 
portion of the forward end of the upper surface of the housing comprises 
at least about one-half of the area of the upper surface extending 
forwardly of the suction mast and has a linear slope at an angle of about 
40 degrees. 
In a second embodiment, the improved cleaner operates with a pool cleaning 
system which is not equipped with a booster pump. In particular, such 
apparatus may comprise a frame having a forward end and a rear end with a 
water inlet mounted on the frame and receiving a supply of water having a 
volume per unit time. The inlet may comprise a supply mast having a number 
of openings for supplying water to the various components of the cleaner. 
The frame is carried on a plurality of transport wheels mounted on the 
frame. The apparatus further includes a vacuum system including a 
collection bag positioned on a suction mast having water injection ports 
positioned such that at least one opening in the water injection port 
injects water toward the collection bag to create suction and draw debris 
into the bag. A drive system is provided to move the apparatus around the 
pool. The drive system includes a turbine having a plurality of vanes 
rotating and mounted in a turbine housing. The turbine housing has a first 
water input and a second water input each oriented to allow a stream of 
water passing therethrough to impact an individual vane at the same angle 
of incidence as the vane passes through each stream. A drive axle couples 
to the turbine and at least one of the plurality of transport wheels. In a 
further aspect the drive system may include thruster jets positioned on 
the mast adjacent to the rear end of the frame. 
An automatic swimming pool cleaner in accordance with the present invention 
has enhanced ability to operate with pool systems not having additional 
booster pumps. These features and advantages of the present invention 
should be apparent from the following detailed description of the 
presently preferred embodiment, taken in conjunction with the accompanying 
drawings, which illustrate by way of example the principles of the 
invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, and particularly to FIGS. 1 and 2 thereof, 
there is shown by way of example a first embodiment of an automatic 
swimming pool cleaner 10, incorporating the principles of the present 
invention. The cleaner 10 includes a frame 12 on which a housing, 
consisting of an upper housing shell 14 and a lower housing shell 16, is 
mounted. An open suction mast 18 for vacuuming debris from beneath the 
cleaner 10 extends through an opening 20, generally in the middle of the 
upper housing shell 14, and a collection bag 22 is attached to the suction 
mast, over a flapper valve 24 positioned on the upper end of the suction 
mast, to collect the debris. A pair of opposing jets 26 and 28 are located 
inside the suction mast 18 (FIG. 2), near its inlet at the bottom of the 
cleaner 10, for inducing a flow of water upwardly through the suction mast 
and into the collection bag 22 in well-known manner. When the cleaner 10 
is operating, the force of the water pushes open the flapper valve 24; 
when the cleaner ceases operating, the flapper valve closes by virtue of 
gravity to keep the debris in the collection bag 22 from failing back into 
the swimming pool through the open suction mast 18. 
A vertically oriented supply mast 30 extends through the opening 20 in the 
upper housing shell 14, behind the suction mast 18, to which a supply hose 
32 is connected for delivering pressurized water to the cleaner 10. A 
float 34 is positioned on a support arm 36 formed integrally with, and 
projecting rearwardly from, the supply mast 30, and a sweep hose 38 is 
connected to a sweep hose jet 40 that similarly projects rearwardly from 
the supply mast. In addition, a thrust jet (not shown) is provided at the 
rear of the cleaner 10. Water from the supply mast is transferred to the 
thrust port, sweep hose 38, jets 26,28 and, as described below, turbine 
46. 
In accordance with the invention, a first wheel 42 and a second wheel 44 of 
equal size are positioned on opposite sides of the cleaner 10, forwardly 
of the suction mast 18, for rotation on a common axis. A turbine 46 is 
mounted within the frame 12 for producing rotary motion in response to a 
pressured water flow supplied thereto via hose 48, which connects to an 
outlet 50 (FIG. 5) near the base of the supply mast 30, within the cleaner 
housing. The turbine 46 is conventional in design, having a water inlet 
port 52, a water wheel 54, a water outlet port (not shown), and a power 
output shaft 56 which is rotated in response to water being supplied to 
the inlet port 52. 
The power output shaft 56 extends axially in both directions from the 
turbine 46 and is journaled for rotation by nylon bearings 58 in mounting 
blocks 60 which are secured by screws 62 in the sidewalls of the frame 12. 
The opposite ends 64 and 66 of the output shaft 56 have splines formed 
thereon in the nature of gears. Each splined end 64 and 66 of the output 
shaft drivingly engages an annular rack 68 and 70 formed on the inner 
surface of the first wheel 42 and the second wheel 44, respectively, as 
seen in FIGS. 2, 3 and 5. It should be recognized that alternate means of 
drivingly engaging wheels, including a friction rubber bearing engaging a 
smooth or textured inner surface of wheel 42 may alternatively be used. 
The sizes of the first wheel 42 and the second wheel 44, and their position 
relative to the frame 12, are such that both wheels extend in the forward 
direction beyond the forward end of the frame. As a result, when the 
cleaner 10 approaches a sidewall or other obstruction while being 
propelled in the forward direction, one or both of the first wheel 42 and 
the second wheel 44 will first make contact and cause the cleaner either 
to turn and proceed in a new direction or else to climb the sidewall or 
other obstruction. 
A third wheel 72 and a fourth wheel 74 of equal size are likewise 
positioned on opposite sides of the cleaner 10, rearwardly of the suction 
mast, and rotate on a common axis. However, unlike the first wheel 42 and 
the second wheel 44, neither the third wheel 72 nor the fourth wheel 74 
are driven by the turbine 46. Instead, both the third wheel 72 and the 
fourth wheel 74 are mounted for freewheeling rotation. 
Each of the first wheel 42, the second wheel 44, the third wheel 72 and the 
fourth wheel 74 is mounted on an axle 76, and each wheel is held in place 
on the axle by a hub screw 78 and washer 80 (shown in FIG. I), 
respectively. As partially shown in FIGS. 2 and 4, each axle 76 is 
integrally molded with a mounting block 82 that is secured in a recess 
formed in the frame 12 by a mounting plate 84 and screws 86. An 
elastomeric tire 88 is mounted on each wheel. 
Although a detailed plan view of the frame 12 is not illustrated in the 
drawings, it is contemplated that many openings will be formed in the 
frame over its lateral and longitudinal extent in order to make it as 
lightweight as practicable, consistent with maintaining appropriate 
structural strength. These openings in the frame 12 also serve to prevent 
air from becoming trapped in the cleaner 10 when it is first submerged in 
the swimming pool, causing the cleaner to float undesirably. At the same 
time, however, it is also contemplated that a brass weight (also not 
shown) will be mounted at the forward end of the frame 12 to increase the 
traction of the first and second wheels 42 and 44. Of course, the float 34 
also has the effect of increasing the traction of the first and second 
wheels 42 and 44 by virtue of the relatively high elevational positioning 
of the float 34 at the rear of the cleaner 10. Frame 12, housing 14,16, 
mast 18 and wheels may be formed of injected molded material. 
Referring again to FIGS. 1, 2 and 5, the forward end portion of the upper 
housing shell 14 includes a sloping portion 90. This sloping portion 90 
comprises a substantially flat or linear surface having an angle of about 
40 degrees to the horizontal plane of the cleaner 10 and comprises about 
one-half of the area of the surface of the upper housing shell 14 
extending forwardly of the suction mast 18. As the cleaner 10 is propelled 
in the forward direction, the force of the water in the swimming pool on 
this sloping portion 90 advantageously tends to push the front of the 
cleaner in a downward direction. This downward force, in conjunction with 
the downward force of the aforementioned brass weight and the 
counterbalancing force applied by the float 34, further increase the 
traction of the first and second wheels 42 and 44 and reduces the tendency 
of the front of the cleaner 10 to lift off the submerged surfaces of the 
swimming pool as the cleaner is propelled in the forward direction. 
For additional traction and reduction of the tendency of the front of the 
cleaner 10 to lift, a spoiler 92 in the form of a relatively long and 
narrow V-shaped plate is shown mounted on the upper housing shell 14 
forwardly of the suction mast 18. As shown in FIG. 7, for convenience of 
fabrication, the spoiler 92 can be formed as a separate part and mounted 
with a snap fit in openings 94 formed in the upper housing shell 14. 
FIGS. 8-16 depict a second embodiment of the automatic pool cleaner in 
accordance with the present invention. In the second embodiment described 
with respect to FIGS. 8-16, it will be recognized that like reference 
numerals designate like parts with respect to the embodiment heretofore 
described with respect to FIGS. 1-7. 
In this second embodiment, a booster pump is not required for effective 
operation of the cleaner. In many applications, it is desirable to utilize 
automatic cleaners with an existing pool installation where a booster pump 
is not installed. Normally, the pool cleaning system is fitted with a 
skimmer which operates a skimmer pump. The skimmer pump may be utilized 
with the automatic pool cleaner of the present invention to power the 
cleaner about the pool. In order to accomplish this, the cleaner must be 
able to operate without placing a strain on the skimmer pump or requiring 
the skimmer pump to generate additional pressure. To meet this need, the 
cleaner must be able to pass the same volume of water per unit time which 
it receives from the pump. 
In a first aspect, the diameter of the supply mast has been increased over 
the first embodiment of the invention. Supply mast 30 in the first 
embodiment of the present invention has a diameter of approximately 
one-half inch. In the second embodiment 100 of the present invention, the 
inner diameter has been increased to approximately 1.0 inches. It should 
be recognized that the diameter of the supply mast 130 need not be 
precisely 1.0 inches but may be calculated to be any diameter which is 
necessary to receive the volume per unit time generated by the particular 
application for which the cleaner 100 is intended. 
In a second unique aspect of the second embodiment of the present 
invention, the novel turbine 146 is utilized. In the embodiment shown in 
FIGS. 9, 10, and 11, the turbine housing 147 includes an upper portion 148 
and a lower portion 149. Upper portion 148 includes two water inlet ports 
152.sub.1, 152.sub.2. As shown in FIG. 9, two conduits 148.sub.1,148.sub.2 
are coupled to outlets 149.sub.1 and 149.sub.2 on supply mast 130 which 
transmit the received water from supply line 132 to inlet ports 
152.sub.1,152.sub.2, respectively. Water inlet port 152.sub.1 is oriented 
so that a water output stream 153.sub.1 is approximately 90.degree. in 
relation to surface 19 of frame 12. Water inlet port 152.sub.2 is oriented 
such that an axis X passing through the center of the inlet port is 
approximately 60.degree. with respect to the surface 19 of frame 12. 
Turbine wheel 54 includes a plurality of vanes 55. It will be recognized 
by one of average skill in the art that the angle of incidence of each of 
the water streams 153.sub.1 and 153.sub.2 emanating from water inlet ports 
152.sub.1 and 152.sub.2 impact vanes 55 at the same angle of incidence as 
a particular vane passes through each given stream. The effect of the 
inlet ports 152.sub.1, and 152.sub.2 is to increase the volume of water 
which is received by the turbine which powers the drive shaft 56 and 
wheels 42,44. Because the water received by supply mast 130 is at lower 
pressure but greater volume, the greater surface area of multiple vanes 55 
must be utilized to maintain the same power for the pool cleaner of the 
second embodiment operating without a booster pump. 
Brass weight 200 (not shown with respect to the first embodiment of the 
present invention), is illustrated in FIGS. 9 and 10. The approximate 
weight of the brass weight is approximately 3.0 oz. 
FIG. 10 illustrates a third aspect of the second embodiment of the present 
invention. Two thrust jets 131,132 are illustrated positioned on the 
supply mast 130. In the first embodiment of the present invention, only 
thrust jet 132 need be utilized. In a second embodiment of the present 
invention, thrust jets 131 and 132 are utilized in order to increase the 
ability of the unit to pass the received water per unit volume into the 
unit, and also to increase the force which the thrust jets provide 
relative to the lower pressure which is received in a supply mast 130. 
Each thrust jet 131,132 comprises a housing 133 and a stem 134 which has, 
at one end, a ball joint being received in the housing 133 enabling 
universal rotation of the thrust jets 131,132. This enables the jets to be 
positioned as desired by the operator of the cleaner for more effective 
cleaning. 
Yet another aspect of the second embodiment of the present invention is 
illustrated with respect to FIGS. 10 and 12 through 15. As shown therein, 
at the base of section mast 118, water injection jets 126 and 128 are 
positioned to transfer water supply via supply mast 130 up into suction 
mast 118 and generate the vacuum necessary to collect debris off the 
surface of the pool. 
FIG. 13 illustrates the embodiment of the suction jet 26 in the first 
embodiment of the present invention. As shown therein, each jet, such as 
jet 26 includes a base portion 26a and a stem portion 26b. The stem 26b 
includes bore 26c which extends the length of the stem 26b to an opening 
26d which is in contact with a transfer conduit, such as conduit 127 shown 
in FIG. 10, to receive water supplied by supply mast 130. 
A second embodiment of the water supply jets is shown in FIGS. 14 through 
16. Jet 126 is similar to jet 26 except that jet 126 includes a second 
opening 126e to a second outlet port 126f so that water transmitted from 
supply mast 133 exits the jet in two places, both up toward the collection 
bag, at the interior of supply mast 130. The second opening increases the 
amount of water which may pass per unit time into supply mast 130 and 
maintaining the same suction strength in the second embodiment of the 
cleaner of the present invention without need for excessive pressure 
therein. 
In a further aspect of the present invention, a back-up valve may be 
provided on supply line 132. After a predetermined volume of water passes 
through the supply line 132, the back-up valve diverts the flow of water 
external to the cleaner, and hence reverses the direction of the suction 
cleaner 100. 
While the position of inlet port 152.sub.2 is shown as being adjacent to 
inlet port 152.sub.1, the position of the inlet port may be at any point 
along the circumference of housing 146 as necessary to complete the 
incidence of the stream 153.sub.2 on the vanes 55. Moreover, multiple 
inlet ports, greater than two, may be utilized. 
Based on the foregoing, it will be appreciated that an improved swimming 
pool cleaner has been shown and described that has enhanced ability to 
function in low pressure supply environments. The cleaner has a highly 
reliable drive train which is substantially encased within the cleaner 
housing such that the drive train has virtually no exposure to potential 
jamming or damage from debris. It will further be appreciated that there 
maybe many configurations for a swimming pool cleaner in which the 
principles of the present invention are applicable. Therefore, the scope 
of the present invention should not be seen as limited except by the 
following claims.