Note: Descriptions are shown in the official language in which they were submitted.
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THIS INVENTION relates to apparatus for
automatically cleaning the submerged surfaces of
swimming pools and the like.
In South African Patent No. 77/6199 there is
described automatic swimming pool cleaning apparatus
which relies for its operation on the intermittent
cutting off of flow through a cleaning head in contact
with the surface of the swimming pool to be cleaned.
The means for cutting off the flow is a flapper valve
of substantially triangular cross-section and which
pivots about the apex of the triangle to open and close
a free flow passage through the head and alternately
open and close a second very restricted passage through
the head. The cleaning head is held in proximity to
15 the surface to be cleaned by a perforated flexible
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annular disc surrounding the head. The inlet open-
ings into the head include a central opening below
the flexible disc and two side openings above the
disc. These side openings are diametrically opposed
and are directed tranverse to the direction of move-
ment of the head. To improve the flow of water and
dirt into the openings they are each provided with a
guide extending outwardly aboYe and across the surface
of the disc. Although a large part of the dirt moving
across the upper surface of the disc is collected in
this manner it is believed that the efficiency of this
collection could be improved.
Another apparatus of the same general type
also has a cleaning head incorporating a flapper valve.
However, it also includes two suc~ion passages which
communicate with the head and flapper valve so that the
flapper valve alternately and repeatedly transfers
liquid flow from the head through the two passages.
An object of this invention is to provide
apparatus, of the type including a cleaning head and
flapper valve, for cleaning submerged surfaces in
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which the efficiency of the collection of the dirt on a
submerged surface may be improved.
In accordance with an aspect of the invention
there is provided an apparatus for cleaning submerged
surfaces, such as the bottoms and walls of swimming pools,
comprising: ~a) a suction head having an inlet and an
outlet, (b) an oscillatory flapper valve disposed within
the suction head between the inlet and outlet, (c) an
annular flexible disc mounted proximate ~he inlet of the
suction head, (d) the inlet being defined by a central
opening disposed below the disc and at least one
transverse opening disposed above and adjacent the disc
the transverse opening being substantially symmetrical
about a direction of movement of the suction head and
facing in the general direction of such movement, ~e) a
substantially sector-shaped upper member disposed above
the transverse opening and extending over a substantial
portion of the disc, and (f) means supporting the upper
member in a spaced relationship relative to the disc,
whereby liquid and dirt dislodged by the apparatus is
guided and funneled by and between the disc and upper
member towards the transverse opening.
Further according to the invention the inlet
located above the disc is located between the disc and an
upper, preferably flexible t member extending above at
least the operatively forward part of the disc and spaced
along its periphery therefrom by a plurality of spaced
substantially radial ribs.
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Still further according to the invention the
periphery of the upper flexible member may, in plan
view, be substantially co-incident with the peri-
phery of the disc and the ribs are integral with the
upper flexible member.
Yet further according to the invention the
inlet opening located abo~e the disc comprises two
similar inlet ports arranged symmetrically about the
direction of movement of the apparatus and the axes of
the ports radiate from the central opening at an angle
of about 45~ to the direction of movement of the
apparatus.
An embodiment of the invention described by
way of example only follows with reference to the
accompanying drawings in which :-
Fig. 1 is a sectional elevation of anapparatus for cleaning submerged
surfaces;
Fig. 2 is a front elevation ~partly sectioned)
ta~en in the direction of arrow "A"
in Fig. 1;
., .
Fig. 3 is a partly sectioned plan view
taken along line III - III in
Fig. 1; and,
Fig. 4 is a second partly sectioned plan
view but taken along line IV IV
in Fig. 1.
In this embodiment of the invention apparatus
for cleaning the submerged surfaces of swimming or
other pools comprises a suction head 1 which i~ of
10 basically rectangular cross-section and having inlet
openings at one end and a circular outlet 2 at the
other end. Located between the inlet openings and
the outlet is an oscillatible flapper valve 3 of
known type.
The end 4 of the head 1 associated with the
inlet openings is a short substantially cylindrical
portion of circular cross-section, the axis of which
is at about 45 to the axis of the main body of the
head and the outlet opening. This cylindrical portion
is bounded by upper and lower outwardly extending
flanges indicated by numerals 5 and 6 resp~ctively
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~ 1 in Fig. ~.
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-- 7 --
The bottom end of the cylindrical portion 4
defines a central opening 7 with suitably spaced feet
8 around the periphexy thereof to provide space between
the inlet 7 and the surface 9 on which the head is
located through which water may flow. Between the two
flanges 5 and 6 are t'wo substantially rectangular inlet
ports 10. These ports have their axes radiating from the
axis of the central opening 7 and at an angle of about
45 to the direction in which the apparatus is designed
to move. This direction is indicated by arrow "X" and,
as will be seen below, the axis of the main bady of the head
1 lies in this direction in plan view.
An annula- d-sc 11 of flexible plastics material
is located on the lower flange 6. The disc has apertures
12 therethrough (only one shown for simplici-ty) which
allow water to pass from the upper surface 13 of the
disc to the central opening 7 when a suction is applied
to the outlet ~ of the head. This limits the force with
which the disc and head are held against the surface
being cleaned.
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Supported on the upper surf~ce of the disc
and in the operatively forward region thereof are a
plurality of spaced short radial ribs 14 formed inte-
gral with an upper flexible member. ~he ribs serve
to space the upper surface of the disc from the lower
surface 15 of the upper flexible member 16 supported
by the body on the upper flange 5. As may be seen
from the drawings the periphery of this flexible member
16 follows that of the disc 11 in plan view and the
flexible member is of roughly sector-shape having an
included angle of about 120.
The ribs may alternatively be made integral
with the disc if this is preferred.
Simply to complete the description of an
15 operative device the following is included in this
specification.
The outlet 2 has a swivelable fitting 17
incorporated therein so that the head can be attached
to a longitudinally extending suction pipe 18 carried
at one end of an elongate flexible suction pipe (not
shown) for attachment to a pump.
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The oscillatable valve 3 is located within the
head between the inlet and outlet so that it may open
or close a passage 19 through the head between the
inlet and outlet. The valve is of substantially
triangular cross-section so that it may oscillate
about its apex ~0 adjacent the outlet. The base of
the valve is slightly peaked as indicated at 21 so
that it may move over and co-operate with a partition
member 2~ located in the inlet end of the head 1 when
water is caused to flow through into the headO
On the side of the valve opposite the flow
passage 19 through the head is a suction communication
which is designed so that there is as restricted an
opening between inlet and outlet of the head as is
commensurate with the proper operation of valve 3.
Water flow through the suction communication is therefor
greatly reduced compared to that through the passage
19~ The suction communication is adapted to be shut
off when the flow passage~is open and is only open for
a brief period when the valve 3 closes the flow passage.
The shape and size of the val~e 3 in the head together
with the location of the partition member 22 constricts
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the suction communication to the size which prevents
appreciable liquid flow therethrough.
Internal formations are provided in th~ head
to constrain the movement of the valve ~ in the head
and form valve seats to close off the flow passaye 19
through the head and suction communication past the
lower end of the valve.
The shape of the base of the valve providing
the peak enables the space 23 between the valve and
partition member ~ to remain substantially constant
as the valve moves between its terminal positions and
is also symmetrical.
~ ith the construction above set forth it has
been found that when the head is submerged and a swim-
ming pool and filter suction applied to the outletthe flow of water causes the valve to oscillate between
its two terminal positions. In one such position the
flow is substantially full and direct through the
opening 19 to the outlet 2 while in the other there is
20 maximum reduction in liquid flow through the head.
This results, in use, to an intermittent cut~off flow
through the head as the valve oscillates between
its terminal positions and this in turn causes
pulsations 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 disc 11 against the
surface to be cleaned a step by s~ep movement of the
head takes place over the surface to be cleaned.
The movement is automatic but random and to
control this a buoyancy chamber 24 is provided. This
will preferably be provided with a hollow float. This
chamber ensures that while the head will sink with the
aid of any necessary weights 25 onto the surface to be
cleaned it will, nevertheless, be correctly orientated
thereto.
Also because the apparatus can operate on
vertical walls it is necessary to provide suitable
counterbalancing to prevent the head from climbing
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above the water level and allow air to be drawn through
the system. This can be easily effected in known manner
by having afreely movable spherical weight 26 in a Vee-
shaped guide 27 attached to the head across the width
thereof. It may be fitted to either the upper or lower
surface of the head.
Reverting now to the invention itself it will
be understood that when the apparatus moves in a forward
direction as indicated by arrow "X" over the surface
being cleaned, a significant amount of the dirt moves
over the upper surface 13 of the disc 11. Because the
ports 10 are directed forwardly this dirt is more easily
sucked into the head. Furthermore, the upper fiexible
member 16 serves as a guide to guide the dirt and liquid
towards the ports thus decreasing the amount of dirt
which is simply stirred up by the machine and allowed
to resettle. The spacing ribs 14 prevent the upper
member from being sucked into complete contact with
the disc thereby preserving the spaced relationship of
the upper flexible member and disc. The ribs also
direct the liquid and dirt towards the ports as shown
by the arrows 28 in Fig. 4, and the two outermost ribs
define outer boundary walls to the effective inlet duct
defined between the disc and upper flexible members.
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Other embodiments are envisaged within the
scope of the invention including its application to
other cleaning apparatuses of the same general type.
It should be noted that the invention may be used
without the upper flexible member which is simply
an accessory which provides for greater cleaning
efficiency.
It also appears that having the openings in
the forward port of the head facilitates its movement
over the surface to be cleaned.
