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(11) | EP 0 543 387 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Improvements in automatic pool cleaners |
| (57) Apparatus for cleaning a surface submerged in a liquid is disclosed and claimed.
The apparatus comprises a body (12) defining a flow passage (28, 32, 16, 18 and 20)
therethrough. The flow passage extends between a main inlet (26) to the body defined
in a peripheral region (22) of the body and an outlet (41) from the body. The peripheral
region (22), in use, being releasably engageable with a surface to be cleaned and
the outlet (41) being connectable to a suction source. A pivotal valve (34) is located
in the body for intermittently varying the flow of liquid through the body (12). The
cleaner is characterised in that it comprises formations (46) for imparting whirling
motion to liquid flowing through at least part of the body (12). |
INTRODUCTION AND BACKGROUND
[0001] THIS invention relates to cleaners for submerged surfaces. More particularly it relates to suction operable automatic swimming pool cleaners.
[0002] Suction operable automatic swimming pool cleaners are known in the art. These machines comprise a body having a planar peripheral region defining an inlet and which region is releasably engageable with a surface to be cleaned. In use, the body is connected via an outlet to an inlet of a pump and filtration system of a swimming pool. In the body there is mounted means for intermittently varying the flow of water through the body, thereby to impart kinetic energy to the body causing the body to move automatically over the surface to be cleaned. As the body moves over the surface, debris is sucked up from the surface through said inlet. One such a cleaner in which the means for intermittently varying the flow of water through the body comprises a pivotal hammer valve is disclosed in US patent 4,023,227. Another cleaner of the kind described is disclosed in US Patent 4,642,833. In this case the means for intermittently varying the flow of water through the body comprises a pinch valve arrangement.
OBJECT OF THE INVENTION
[0003] It is an object of the present invention to provide alternate apparatus for cleaning a surface submerged in a liquid which the applicants believe will have improved operation.
SUMMARY OF THE INVENTION
[0004] According to the invention there is provided apparatus for cleaning a surface submerged in a liquid, the apparatus comprising a body defining a flow passage therethrough, the flow passage extending between a main inlet to the body defined in a peripheral region of the body and an outlet from the body, the peripheral region, in use, being releasably engageable with a surface to be cleaned and the outlet being connectable to a suction source; means located in the body for intermittently varying the flow of liquid through the body; and means for imparting whirling motion to liquid flowing through at least part of the body.
[0005] The means for intermittently varying the flow of liquid through the body is preferably located downstream of the means for imparting whirling motion to liquid flowing through at least part of the body.
[0006] The means for imparting whirling motion to liquid flowing through at least part of the body may comprise a plurality of curvilinear projections provided in said peripheral region of the body and defining a plurality of curvilinear channels between them.
[0007] The plurality of curvilinear projections are preferably provided on a face of a footpad, which is removably mountable on the body in the peripheral region thereof.
[0008] The means for imparting whirling motion to liquid flowing through at least part of the body may alternatively or in addition comprise two further inlets defined in asymmetric regions in opposed sidewalls of the body between said main inlet and said outlet. The two further inlets may be offset relative to one another on a line which is substantially parallel to a general plane of the peripheral region. The two further inlets may have different sizes.
[0009] In one embodiment of the apparatus according to the invention the body comprises a head defining a chamber communicating with said main inlet and first and second exits from the head; first and second elongate drive tubes communicating with the first and second exits; and a coupling arrangement connected to said first and second tubes and which coupling arrangement defines said outlet from the body; and the means for intermittently varying the flow of liquid through the body comprises a pivotal valve located in the chamber and which valve, in use, pivots between a first position wherein it obstructs said first exit and a second position wherein it obstructs said second exit.
[0010] It has been found that it is advantageous to straighten the flow through the drive tubes and therefore at least one of said first and second elongate drive tubes may comprise at least one axially extending internal strake.
[0011] Also included within the scope of the present invention is a footpad for a cleaner for a surface submerged in a liquid comprising a disc-like body defining an opening for communicating with a main inlet of the cleaner; a plurality of curvilinear projections provided on one face of the disc-like body defining a plurality of curvilinear channels between them, the channels extending from a peripheral outer region of the body to the opening. At least one of the projections may be made of a resilient porous material.
[0012] Also included within the scope of the present invention is an elongate drive tube for a cleaner for a surface submerged in a liquid comprising at least one internal axially extending strake.
[0013] The invention also includes within its scope apparatus for cleaning a surface submerged in a liquid and which apparatus comprises a body defining a flow passage therethrough extending between a main inlet and an outlet from the body; the body comprising a head defining the main inlet, a chamber and a pair of exits from the chamber, the body further comprising a pair of elongate drive tubes communicating with the pair of exits, and a coupling arrangement connected to the pair of drive tubes and defining the outlet from the body; the apparatus further comprising a pivotal valve having a pair of opposed sealing faces for cooperating with a pair of seats at said pair of exits, in use, alternately and repeatedly to obstruct said exits; at least one pair of said pair of exits, said pair of elongate drive tubes, said pair of sealing fares and said pair of valve seats being asymmetrical.
BRIEF DESCRIPTION OF THE DIAGRAMS
[0014] The invention will now further be described, by way of example only, with reference to the accompanying diagrams wherein:
- figure 1
- is a diagrammatic side view of a cleaner according to the invention for cleaning a surface submerged in a liquid;
- figure 2
- is a diagrammatic view of a footpad of the cleaner, in the direction of arrow A in figure 1;
- figure 3
- is a section on line III in figure 1;
- figure 4
- is a transverse section through an elongate drive tube forming part of the cleaner;
- figure 5
- is a diagrammatic enlarged view, partially sectioned, of the region identified as X in figure 1;
- figure 6
- is a diagrammatic enlarged view, partially in section, of the region identified as Y in figure 5; and
- figure 7
- is a diagrammatic enlarged view of the region identified as Z in figure 1.
DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION
[0015] A suction operable automatic swimming pool cleaner according to the invention is generally designated by the reference numeral 10 in figure 1.
[0016] The cleaner comprises a body 12 comprising a head 14, first and second elongate drive tubes 16,18 extending from the head 14 and a coupling arrangement 20. The body defines a flow passage for water therethrough extending between a main inlet 26 to the body and an outlet 41 from the body.
[0017] The head 14 has a planar peripheral region 22 provided by a flange 24. The main inlet 26 is defined in the peripheral region. Main inlet 26 communicates with a lower chamber 28 which is bounded by a baffle plate 29 defining a port 30 communicating with chamber 32, for pivotal hammer valve 34. Chamber 32 has first and second exits 36 and 38 communicating with the elongate drive tubes 16 and 18 respectively.
[0018] Coupling arrangement 20 comprises a swivel coupling 40 defining outlet 41 and which coupling, in use, is connectable via a flexible hose (not shown), to an inlet of a pump and filtration system (also not shown) of a swimming pool.
[0019] As best shown in figure 7, in chamber 32 and about each of exits 36 and 38 there is provided a valve seat 36.1 and 38.1 respectively. Valve 34 having opposed sealing faces 34.1 is mounted off-centre in chamber 32 and, in use, pivots under the influence of water flow through chamber 32, between a first position wherein it obstructs exit 35 and a second position wherein it obstructs exit 38.
[0020] As shown in figure 1, a footpad 42 is removably mountable on flange 24. As best shown in figure 2, the footpad 42 comprises a circular body 43 defining a central hole 44, which, in use, communicates with main inlet 26. On the bottom surface of footpad 42 which, in use, bears on the surface being cleaned, there are provided a plurality of curvilinear projections 46 defining a plurality of curvilinear channels 48 extending inwardly towards the hole 44 from the outer periphery of the footpad. At least some of the projections are made of a porous resilient material.
[0021] As shown in figures 1 and 3, in opposed sidewalls 14.1 of head 14 and in the region of lower chamber 28, there are defined two further inlets 50 and 52 which are offset relative to one another on a line which is parallel with the plane of the peripheral region 22.
[0022] In use, the apparatus assumes the attitude illustrated in figure 1 on a submerged horizontal surface to be cleaned. When suction is applied to the apparatus 10 by the said pump, water entraining debris enters the body via curvilinear channels 48, hole 44 and main inlet 26. The curvilinear channels impart a whirling motion to the water entering the body. Water is also admitted through offset further inlets 50 and 52, which also impart whirling motion to the water admitted.
[0023] The water flows through chamber 28, port 30 and chamber 32 towards outlet 41. As more fully described in US patent 4,023,227, water flowing past the valve 34 causes the valve to pivot between the said first and second positions, thereby alternately and repeatedly to obstruct flow through exits 36 and 38. This alternate and repeated obstruction of exits 36 and 38 causes kinetic energy in a body of water stopped as a result of such obstruction, to be transferred to the cleaner body, thereby to cause the cleaner automatically to move over the surface in the direction indicated by arrow B, shown in figure 1.
[0024] The projections 46 made of a resilient foam material act like suction pads and serve to improve traction of the footpad 42 on the surface being cleaned.
[0025] As illustrated in figure 4, each drive tube 16, 18 comprises a plurality of axially and radially inwardly extending internal strakes 53. These strakes serve to straighten the flow of water as it passes through the drive tubes 16, 18.
[0026] As is clear in figure 6, there is defined a clearance 53 between swivel coupling 40 and a bearing 54 which is a friction fit in the body of coupling arrangement 20. A washer 56 is supported on an inwardly directed flange 58 on the body below the lower end of the coupling 40 and is so shaped that water drawn into the coupling arrangement through the clearance 53 is directed along the inside wall of the coupling 40 in the same direction as the main water flow. This arrangement not only reduces vortices in flow in the region of the coupling arrangement 20, but also increases the flow towards the pump by as much as 5%.
[0027] The bumper arrangement 60 shown in figure 1 is made of a material having a specific gravity greater than that of water. This increased weight together with the leverage effect of being applied at a distance from the body 12, improves the ability of the cleaner 10 to turn off a sidewall (not shown) of a swimming pool (also not shown).
[0028] As shown in figure 1, the external fins 62 on the head 14 are slightly inclined relative to the plane of the peripheral region 22. These fins act like airfoils to press the cleaner 10 into closer contact with the surface being cleaned.
[0029] It has also been found that the operation of the cleaner described hereinbefore may be improved by introducing asymmetry between two corresponding parts of the cleaner. For example, the two drive tubes 16, 18 and/or exits 36 and 38 may have slightly different diameters. Furthermore or alternatively, the sealing of the hammer valve 34 on seats 36.1 and 38.1 respectively may be different. This may be achieved by mounting a symmetrical valve 34 off centre in chamber 32. It may also be achieved by providing the valve 34 with asymmetrically curved sealing faces as shown at C in the broken lines in figure 7. Another or additional way to achieve asymmetry is to provide asymmetrically positioned holes 64.1 and 64.2 in valve 34, one of which 64.2 straddles one edge of the corresponding valve seat 38.1, in chamber 32. In another embodiment a plurality of holes may be provided in the hammer. It has been found that such holes reduce noise emitted by the cleaner during operation.
[0031] By adopting one or more of the features discussed above, it has been found that the cleaner operates with reduced noise, the frequency of oscillation is reduced, debris or the like is maintained in suspension and are more readily picked up and there is an increase in the flow of water through the cleaner.
1. Apparatus for cleaning a surface submerged in a liquid, the apparatus comprising a
body (12) defining a flow passage (28, 32, 16, 18 and 20) therethrough, the flow passage
extending between a main inlet (26) to the body defined in a peripheral region (22)
of the body and an outlet (41) from the body, the peripheral region, in use, being
releasably engageable with a surface to be cleaned and the outlet being connectable
to a suction source; and means (34) located in the body for intermittently varying
the flow of liquid through the body, the cleaner being characterised in that it comprises means (48) for imparting whirling motion to liquid flowing through at
least part of the body.
2. Apparatus as claimed in claim 1 wherein the means for intermittently varying the flow
of liquid through the body is located downstream of the means for imparting whirling
motion to liquid flowing through at least part of the body.
3. Apparatus as claimed in claim 2 wherein the means for imparting whirling motion to
liquid flowing through at least part of the body comprises a plurality of curvilinear
projections (46) provided in said peripheral region of the body and defining a plurality
of curvilinear channels (48) between them.
4. Apparatus as claimed in claim 3 wherein the plurality of curvilinear projections are
provided on a face of a footpad (42), which is mounted on the body in the peripheral
region thereof.
5. Apparatus as claimed in claim 4 wherein the footpad is removably mountable on a flange
(24) in the peripheral region of the body.
6. Apparatus as claimed in any one of the preceding claims wherein the means for imparting
whirling motion to liquid flowing through at least part of the body comprises at least
two further inlets (50, 52) defined in asymmetric regions in opposed sidewalls (14.1)
of the body.
7. Apparatus as claimed in claim 6 wherein the two further inlets have different sizes.
8. Apparatus as claimed in any one of the preceding claims wherein the body comprises
a head (14) defining a chamber (32) communicating with said main inlet and first and
second exits (36,38) from the head; first and second elongate drive tubes (16,18)
communicating with the first and second exits; and a coupling arrangement (20) connected
to said first and second tubes and which coupling arrangement defines said outlet
from the body; wherein the means for intermittently varying the flow of liquid through
the body comprises a pivotal valve (34) located in the chamber and which valve, in
use, pivots between a first position wherein it obstructs said first exit and a second
position wherein it obstructs said second exit.
9. Apparatus as claimed in claim 8 wherein the head has external fins (62) thereon which
are inclined relative to a general plane of said peripheral region.
10. Apparatus as claimed in claim 8 or claim 9 comprising a bumber assembly (60) arching
out from the body, the bumber assembly being made of a material having a specific
gravity greater than that of water.
11. Apparatus as claimed in any one of claims 8 to 10 wherein at least one of said first
and second elongate drive tubes comprises at least one axially extending internal
strake (53).
12. A footpad (42) for a cleaner (10) for a surface submerged in a liquid comprising a
disc-like body (43) defining an opening (44) for communicating with a main inlet (36)
of the cleaner; a plurality of projections (46) provided on one face of the disc-like
body, the footpad being characterised in that the projections (46) are curvilinear in configuration defining a plurality of curvilinear
channels (48) between them, the channels extending from a peripheral outer region
of the body to the opening.
13. A footpad as claimed in claim 12 wherein at least one of the projections is made of
a resilient porous material.
14. An elongate drive tube (16,18) for a cleaner (10) for a surface submerged in a liquid,
the drive tube being characterised in that it comprises at least one internal axially extending strake (53).
15. Apparatus for cleaning a surface submerged in a liquid, the apparatus comprising a
body (12) defining a flow passage (28, 32, 16, 18 and 20) therethrough extending between
a main inlet (36) and an outlet (41) from the body; the body comprising a head (14)
defining the main inlet, a chamber (32) and a pair of exits (36, 38) from the chamber;
a pair of elongate drive tubes (16, 18) communicating with the pair of exits; and
a coupling arrangement (20) connected to the pair of drive tubes and defining the
outlet; the apparatus further comprising a pivotal valve (34) located in the chamber,
the pivotal valve having a pair of opposed sealing faces (34.1) for cooperating with
a pair of seats (36.1, 38.1) at said pair of exits, in use, alternately and repeatedly
to obstruct said exits; the apparatus being characterised in that at least one pair of said pair of exits, said pair of elongate drive tubes, said
pair of sealing faces and said pair of valve seats is asymmetrical.
16. Apparatus as claimed in any one of claims 8 to 15 wherein there is provided a baffle
plate (29) between the main inlet 26 and the chamber and wherein a port (30) is defined
off-centre in the baffle plate.
17. Apparatus as claimed in any one of claims 8 to 16 wherein the valve is mounted off-centre
in the chamber.
18. Apparatus as claimed in any one of claims 15 to 17 wherein at least one hole (64.1,
64.2) is defined in each of said sealing faces of the valve.
19. Apparatus as claimed in any one of claims 15 to 18 wherein at least two further inlets
(50, 52) are defined in asymmetric regions in opposed sidewalls 14.1 of the head in
a region upstream from the valve.