Cleaning apparatus for submerged surfaces

Cleaning apparatus of the type including a cleaning head for cleaning submerged surfaces and a flapper valve for moving the head relative to the surface by oscillation thereof. An annular flexible disc located at the inlet end of the suction head surrounds a central opening below the flexible disc and at least one transverse inlet opening to the passage through the suction head is located above and adjacent the flexible disc. The transverse inlet opening is substantially symmetrical about the direction of movement of the head and faces in the general direction towards which the head moves in operation. An upper member held in spaced relation relative to the disc may be provided to define a flow path between it and the disc towards the transverse inlet opening.

This invention relates to apparatus for automatically cleaning the 
submerged surfaces of swimming pools and the like. 
In South African Pat. 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 the 
surface to be cleaned by a perforated flexible annular disc surrounding 
the head. The inlet openings 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 transverse to the 
direction of movement of the head. To improve the flow of water and dirt 
into the openings they are each provided with a guide extending outwardly 
above 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 suction 
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 
which the efficiency of the collection of the dirt on a submerged surface 
may be improved. 
According to the invention cleaning apparatus of the type including a 
cleaning head and flapper valve for cleaning submerged surfaces comprises 
an annular flexible disc located at the inlet end of a suction head, the 
suction head including a flapper valve between the inlet and outlet 
therefor and the inlet comprising a central opening below the flexible 
disc and at least one transverse opening located above and adjacent the 
flexible disc so as to be substantially symmetrical about the direction of 
movement thereof and to face in the general direction towards which the 
head moves in operation. 
Further according to the invention the inlet located above the disc is 
located between the disc and an upper, preferably flexible, 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. 
Still further according to the invention the periphery of the upper 
flexible member may, in plan view, be substantially co-incident with the 
periphery of the disc and the ribs are integral with the upper flexible 
member. 
Yet further according to the invention the inlet opening located above 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.degree. to the direction 
of movement of the apparatus.

In this embodiment of the invention apparatus for cleaning the submerged 
surfaces of swimming or other pools comprises a suction head 1 which is of 
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.degree. 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 respectively in 
FIG. 1. 
The bottom end of the cylindrical portion 4 defines a central opening 7 
with suitably spaced feet 8 around the periphery 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 two 
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.degree. 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 body of the head 1 lies in this direction in plan view. 
An annular disc 11 of flexible plastics material is located on the lower 
flange 6. The disc has apertures 12 therethrough (only one shown for 
simplicity) 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 2 of 
the head. This limits the force with which the disc and head are held 
against the surface being cleaned. 
Supported on the upper surface of the disc and in the operatively forward 
region thereof are a plurality of spaced short radial ribs 14 formed 
integral with an upper flexible member. The 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.degree.. 
The ribs may alternatively be made integral with the disc if this is 
preferred. 
Simply to complete the description of an 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. 
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 20 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 22 located in 
the inlet end of the head 1 when water is caused to flow through into the 
head. 
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 valve 3 in the head together with the 
location of the partition member 22 constricts the suction communication 
to the size which prevents appreciable liquid flow therethrough. 
Internal formations are provided in the head to constrain the movement of 
the valve 3 in the head and form valve seats to close off the flow passage 
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 22 to remain substantially constant 
as the valve moves between its terminal positions and is also symmetrical. 
With the construction above set forth it has been found that when the head 
is submerged and a swimming pool and filter suction applied to the outlet 
the 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 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 step 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 above 
the water level and allow air to be drawn through the system. This can be 
easily effected in known manner by having a freely 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 flexible 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. 
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 part of the head 
facilitates its movement over the surface to be cleaned.