WO1999024683A1

WO1999024683A1 - A device for cleaning a submerged surface

Info

Publication number: WO1999024683A1
Application number: PCT/GB1998/003319
Authority: WO
Inventors: Richard Victor Vos; John Errol Styger
Original assignee: Copping, Charles, Montague; Skone James, Robert, Edmund
Priority date: 1997-11-06
Filing date: 1998-11-06
Publication date: 1999-05-20
Also published as: AU9756398A

Abstract

Disclosed is a drive unit for an automatic pool cleaner (APC) and an APC incorporating such a drive unit. The drive unit consists of a body (30) and a fluid control valve arrangement (56) located in the flow passage defined by the body (30). The valve arrangement (56) consists of a pair of jaw-like valve closure members (68) arranged to open and close in a reciprocal manner intermittently to interrupt the flow of fluid and propel the APC over a surface to be cleaned.

Description

A DEVICE FOR CLEANING A SUBMERGED SURFACE

BACKGROUND OF THE INVENTION

This invention relates to a device for cleaning a submerged surface such as that of a swimming pool, for example, hereinafter referred to as an automatic pool cleaner (APC) device.

Automatic pool cleaners are well known. Cleaning devices of this type typically move over the surface to be cleaned in an intermittent, step-wise manner. This step-wise movement is achieved by providing a valve arrangement for intermittently interrupting the flow of water through the device induced by the suction of a conventional swimming pool filtration plant.

A number of valve arrangements have been proposed. One of the most well

SUBS 111 U I h SHEET (RULE 26) known and reliable automatic pool cleaners uses a so-called hammer- or flapper-valve arrangement. The oscillating action of the valve opens and closes a passage, or pair of passages, intermittently to move the pool cleaner device. A problem associated with this type of arrangement is that the passage, and hence the body, has to be fairly large to allow a sufficient volume of water to be drawn through the device to oscillate the valve. Further, the body or housing is of a relatively heavy construction to combat outer housing fatigue caused by the hammer action of the valve. It is also believed that the valve ports are not always efficiently sealed, reducing the effectiveness of the system.

Another well known APC uses a diaphragm arrangement to intermittently interrupt the flow of water. The diaphragm is typically in the form of an elongate tube which is arranged to transversely contract and expand to interrupt the flow of water. Although this arrangement is believed to be the most efficient system currently used, it is not the most reliable. The diaphragm tends to dilate over time, reducing the efficiency thereof. It may even dilate to such an extent that it no longer operates at all. Further, these diaphragms are prone to puncturing by sharp objects sucked up through the APC. Puncturing of the diaphragm renders the APC inoperative.

An attempt has been made to overcome the problems of the diaphragm by using a squat, more robust diaphragm arrangement assisted by a stainless steel spring. This system, however, has a limited power band and is therefore not very versatile. At certain vacuums, this diaphragm tends to remain open, effectively terminating the function thereof. SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided a drive unit for an automatic pool cleaning device comprising:

a body having an inlet and an outlet and defining a flow passage between the inlet and the outlet, and

a fluid control valve arrangement located in the flow passage for controlling the flow of liquid through the passage, the valve arrangement comprising a pair of spaced apart jaw-like valve closure members reciprocally, transversely movable towards and away from one another between respective open and closed positions thereby intermittently to interrupt the flow of fluid through the passage,

wherein intermittent interruption of the flow of fluid through the passage causes propulsion of the automatic pool cleaning device over a submerged surface to be cleaned.

The fluid control valve preferably includes a flange orientated normal to the flow of fluid through the passage, the valve closure members extending away from the flange generally parallel to the flow of fluid.

The flange preferably defines at least one primary apermre for allowing a primary flow of liquid through the passage and at least one auxiliary aperture for allowing an auxiliary flow through the passage, the primary flow of fluid through the passage being interrupted by the valve closure members closing under a suction applied to the drive unit, the suction on the valve closure members being broken by the auxiliary flow of fluid through the passage causing the valve closure members to open, propulsion of the pool cleaning device being caused by the repetition of this cycle.

The flange is preferably fixed to the body with the valve closure members extending towards the inlet.

An elongate mbular member preferably extends along the passage from the primary aperture of the flange towards or through the outlet, the mbular member dividing the passage into a primary passage extending through the mbular member to allow for the primary flow of fluid, and an auxiliary passage along the outside of the mbular member to allow for the auxiliary flow of fluid.

The valve closure members are preferably biased into the open position, typically by being formed of a resilient plastics material.

The valve closure members preferably define opposed sealing edges or faces to provide a tight seal in the closed position. Opposed inserts are preferably provided at or adjacent the opposed sealing edges or faces, the inserts being formed of a generally softer resilient material than that of the valve closure members so as to wrap around any foreign object(s) lodged between the opposed sealing edges or faces in the closed position to ensure that a tight seal is achieved.

The body preferably includes a housing defining a generally hollow chamber in which the fluid control valve arrangement is located. The valve arrangement divides the chamber into a primary chamber in fluid communication with the primary flow passage and an auxiliary chamber in fluid communication with the auxiliary flow passage, a reduction in pressure in the primary chamber causing the valve closure members to close whilst a reduction in pressure in the auxiliary chamber causes the vacuum in the primary chamber to be broken, allowing the valve closure members to open.

Control means are preferably provided for controlling the movement of the valve closure members.

According to a further aspect of the invention there is provided an automatic pool cleaning device for cleaning a submerged surface, the device comprising:

a body having an inlet arranged to be disposed proximate to the submerged surface to be cleaned, an outlet including connection means for operative connection to a flexible suction hose, and a passage defined between the inlet and outlet to allow liquid to be drawn therethrough by suction applied to the outlet; and

a drive unit for driving the pool cleaning device across the surface to be cleaned, the drive unit comprising a body having an inlet and an outlet and a fluid control valve arrangement located in the flow passage for controlling the flow of fluid through the passage, the valve arrangement comprising a pair of spaced apart jaw-like valve closure members reciprocally, transversely movable towards and away from one another between respective open and closed positions thereby intermittently to interrupt the flow of fluid through the passage,

wherein intermittent interruption of the flow of fluid through the passage causes propulsion of the automatic pool cleaning device over a submerged surface to be cleaned. BRTEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a cross-sectional view of one embodiment of an automatic pool cleaning device of the invention;

Figure 2 shows an exploded, perspective view of the drive unit of the automatic pool cleaning device of Figure 1 ;

Figure 3 shows a perspective view of the valve arrangement of the drive unit of Figure 2:

Figure 4 shows a cross-section on the line 4-4 in Figure 2:

Figure 5 shows a side view of the valve arrangement of Figure 3 ; and

Figure 6 shows a side-elevation view, partially in cross-section, of an alternative embodiment of an automatic pool cleaning device of the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

In one embodiment of the invention, an automatic pool cleaning device or APC 10 of the invention, as shown in Figure 1 , consists of a suction head

SUBS 11 i U I E SHEET (RULE 26) 12 and a drive unit 14 which drives the suction head 12 across a submerged surface to be cleaned, typically a submerged surface of a swimming pool.

The suction head 12 has an inlet 16 and a flexible, circular disc 18 that surrounds the inlet 16 and is arranged under suction to engage the surface to be cleaned. The circular disc 18 has a castellated profile and includes a number of channels 20 which guide or channel the water and debris entrained therein through the inlet 16. The suction head 12 includes a port 22 through which the end 24 of the drive unit 12 extends. A passage 26 is generally defined between the inlet 16 and the port 22, the drive unit 14 extending along the passage 26.

Also surrounding the inlet 16 is an annular, castellated foot 28 made of a flexible plastics or synthetic rubber material. The foot 28 is arranged to grip the surface to be cleaned under suction to provide the suction head 12 with additional grip, particularly when cleaning a vertical surface, such as that of a side wall of a swimming pool.

The drive unit 14 consists generally of a body 30 including a valve arrangement 32, an outer elongate mbe 34 terminating in a connector 36 for connection to a flexible suction hose (not shown), and an inner mbe 38 which extends co-axially through the centre of the outer mbe 34.

The drive unit can be seen more clearly in Figure 2. The valve arrangement 32 consists of a rectangular, hollow housing 40 which includes an inlet 42 defined in the front wall 44 and an outlet 46 defined in the rear wall 48. The outer mbular member 34 is attached to the rear wall 44 and extends between the outlet 46 and the connector 36. Positioned at substantially the mid point between the front wall 44 and the rear wall 48 is an internal wall or partition 50. The partition 50 includes a central apermre 52 and a number of peripheral apertures 54, three on each side of the central apermre 52 in this case. The fluid control valve 56 is fixed in the housing 40 between the partition 50 and the front wall 44.

The fluid control valve 56, as shown more clearly in Figure 3, includes a base or flange 58, which is fixed to the partition 50 and the housing walls 60, 62, 64 and 66, and a pair of jaw-like valve closure members 68 which extend away from the base 58 towards the front wall 44 and terminate in free-ends 69. The flange 58 and valve closure members 68 are integrally formed from a resilient plastics material such as a urethane based plastics material, for example. The flange 58 includes a central aperture 70 which corresponds to the central aperture 52 of the partition 50, and a number of peripheral apertures 72 likewise corresponding to the peripheral apertures 54 of the partition 50. The inner mbe 38 is connected to the partition 50 and extends away from the apermre 52 towards the outlet or mouth 73 of the connector 36.

The side walls 64 and 68 of the housing 40 include a first, central stopper formation or inhibitor 74 which is positioned between the valve closure members 68 and a pair of second, outer stopper formations or inhibitors 76 which are positioned behind each valve closure member 68.

As can be seen more clearly in Figure 4. the profiles of the valve closure members 68 and the respective inhibitors 74 and 76 correspond. Under suction, the valve closure members 68 move towards and away from one another in a step-wise or intermittent manner. The stopper formations 74 and 76 prevent the valve closure members 68 from either opening or closing too far. The front wall 44 is curved so as not to obstruct the movement of

SUBSTTTUTE SHEET (RULE 25) the free ends 69 of the respective valve closure members 68. which movement tends to be radial (following the curvature of the front wall 44) as opposed to linear. Shims 77 formed of a frictionless plastics material are latticed or attachable to the valve arrangement 56 so as to form a seal between the valve arrangement 56 and the respective valves 64 and 66 whilst allowing the valve closure members 68 to operate effectively.

The drive unit 14 is advantageously removable from the suction head 12 through the inlet 16. This simplifies the procedure of repairing or replacing the drive unit 14 or a part thereof.

When a suction hose from a conventional filtration plant is connected to the connector 36 and a suction applied, a primary flow of water is drawn through the valve housing 40 and along the primary passage 78 extending through the inner mbe 38. As a result of this primary flow of water, the valve closure members 68 are caused under suction to move towards one another such that the sealing edges 80 of the respective free ends 69 engage one another to interrupt the primary flow of water. The interruption of the primary flow causes an auxiliary flow of water to be drawn from the valve housing 40, via the auxiliary apertures 72 and 54, respectively, through the auxiliary passage 82 defined between the inner mbe 36 and the outer mbe 32 towards the outlet 73.

As a consequence of the auxiliary flow of liquid, the suction vacuum holding the valve closure members 68 closed is broken. Since the valve closure members 68 are formed from a resilient material and are biased into the open position, they temporarily open to once again allow the primary flow of water. In this manner, an apermre 84 defined between the free ends 69 of the respective valve closure members 68, as depicted in Figure 4, is

SUBSTTTUTE SHEET (RULE 26) consecutively opened and closed to intermittently interrupt the primary flow of water through the drive unit 14. As a result of this action, the suction head 12 is caused to travel across the surface to be cleaned in an intermittent, step-wise fashion.

Turning to Figure 5, it can be seen that the fluid control valve 56 has been specifically configured and dimensioned to optimise the functioning thereof. The valve closure members 68, in particular, are carefully manufactured to ensure that they are able repeatedly to provide a tight seal when in a closed position, while reducing the overall strain on the valve assembly. For instance, it will be noted that the fixed ends 86 of the valve closure members 68 are curved. This is believed to reduce the strain these areas when the valve closure members 68 are forced under suction to open and close. In addition, the curvamre of the jaws or arms 88 correspond to the profile of the inhibitor 74 to further ensure a tight seal when the valve closure members 68 are closed and to reduce the strain on the arms 88 during the oscillating motion of the valve closure members 68.

In an alternative embodiment of the invention, as shown in Figure 6, an automatic pool cleaning device or APC 90 consists of a suction head 92 and a drive unit 94 which drives the suction head 92 across a submerged surface to be cleaned.

The suction head 92 has an inlet 96 and a flexible, circular disk 98 surrounding the inlet 96 which is arranged under suction to engage the surface to be cleaned. The circular disk 98 once again has a castellated profile and includes a number of channels 100 which guide or channel the water and debris entrained therein through the inlet 96. The suction head 92 includes a port 102 through which the end 104 of the drive unit 92 extends. A passage 106 is generally defined between the inlet 96 and the port 102, the drive unit 94 extending along the passage 106.

An annular foot 108 made of a flexible plastics or synthetic rubber material and having gripping formations 109 surrounds the inlet 96. The foot 108 is arranged to grip the surface to be cleaned under suction to provide the suction head 92 with additional grip.

The drive unit 94 consists generally of a body 110 including a valve arrangement 112, a squat outer elongate mbe 114 terminating in a connector 116 for connection to a flexible suction hose 118, and an elongate inner mbe 120 which extends co-axially through the centre of the outer mbe 114 and projects through the connector 116. Save for having a squat outer mbe 114, the remainder of the valve arrangement 112 is as depicted in Figure 2. Once again, the valve arrangement 112 consists of a rectangular, hollow housing 122 which includes an inlet 124 defined in the front wall 126 and an outlet 128 defined in the rear wall 130. The outer mbular member 114 is attached to the rear wall 130 and extends between the outlet 128 and the connector 116. Positioned intermediate the front wall 126 and the rear wall 130 is an internal wall or partition 132. The partition 132 includes a central aperture 134 and a number of peripheral apertures 136, three on each side of the central apermre 134 in this case. The fluid control valve 112 is fixed in the housing 122 between the partition 132 and the front wall 126.

The fluid control valve 112 includes a base or flange 138, which is fixed to the partition 132 and the housing walls 140, 142, 144 and another (not shown), and a pair of jaw-like closure members 146 which extend away from the base 138 towards the front wall 126 and terminate in free ends 148. The free ends 148 include inserts 149 of relatively soft resilient

SUBSTTTUTE SHEET (RULE 26) material, such as synthetic rubber for example. The insets 149 are able to wrap around objects lodged between the sealing edges or faces to as to achieve a tight seal. The flange 138 includes a central apermre 150 which corresponds to the central apermre 134 of the partition 132, and a number of peripheral apertures 152 likewise corresponding to the peripheral apertures 136 of the partition 132. The inner mbe 120 is connected to the partition 132 and extends away from the aperture 150 through the outlet or mouth 154 of the connector 116.

The side walls 140 and the other not shown of the housing 122 each include a first, central stopper formation or inhibitor (not shown) which is positioned between the valve closure members 146 and a second, outer stopper formation or inhibitor (not shown) which is positioned behind each valve closure member 146. Once again the profiles of the valve closure members and the respective inhibitors correspond. Instead of having inhibitors, these side walls may include recesses shaped to accommodate the profiles of the valve closure members 146. The stopper formations or recesses thus prevent the valve closure members from either opening or closing to far. Once again the front wall 126 is curved so as not to obstruct the movement of the free ends 148 of the respective valve closure members 146.

The housing 92 includes a float chamber 156 which may be hollow or include a float such as a hollow ball, for example and a weight chamber 158 including a weight such as a lead ball for example. The combination of the float chamber 156 and weight chamber 158 maintain the correct orientation of the body 92 and thus the suction disk 98 relative to the surface to be cleaned. The body 92 also includes a number of apermres or intakes 160 for sucking in debris which is not able to pass through the bottom intake 96

SUBSTTTUTE SHEET (RULE 26) such as large leaves or the like.

It is believed that the automatic pool cleaner (10, 90) of the invention provides a number of advantages over conventional APC's. Due to the fixed base arrangement of the fluid control valve (56, 112) there is effectively only one moving part, that being the valve closure members (68, 146). In addition, most of the force generated by the movement of the valve closure members (68, 146) is absorbed by the sealing edges or faces of the respective valve closure members. As a consequence, there is very little fatigue or strain on the housing (40, 122) or the suction head (12, 92) itself.

Further, the fluid control valve (56, 112) is made of a robust, resilient material. Consequently, it is not prone to damage by sharp objects being sucked through the suction head (12, 92). A further advantage is that the so-called central-lock seal which is created between the sealing edges or faces is a very effective and tight seal. As a consequence, a large enough suction force is produced to propel the suction head (12, 92) out of tight corners. The pool cleaner device of the invention is, therefore, less prone to being smck in one particular place for any significant period of time than other conventional pool cleaning devices.

Further, because of the efficient action of the fluid control valve (56, 112) the drive unit (14, 94) is relatively small and compact. Accordingly, the suction head (12, 92) is also much smaller than conventional APC's, making it safer for persons swimming in a swimming pool in which the APC of the invention is operating.

Finally, due to the design of the APC of the invention, there are relatively few parts and it is relatively simple to assemble or repair. Accordingly, the costs involved in manufacmring and maintaining the device are not exorbitant.

SUBSTTTUTE SHEET (RULE 25)

Claims

1. A drive unit for an automatic pool cleaning device comprising:

a body having an inlet and an outlet and defining a flow passage between the inlet and outlet; and

a fluid control valve arrangement located in the flow passage for controlling the flow of fluid through the passage, the valve arrangement comprising a pair of spaced apart jaw-like valve closure members reciprocally, transversely movable towards and away from one another between respective open and closed positions thereby intermittently to interrupt the flow of fluid through the passage,

2. A drive unit according to claim 1 , wherein the fluid control valve includes a flange orientated normal to the flow of fluid through the passage, the valve closure members extending away from the flange generally parallel to the flow of fluid.

3. A drive unit according to claim 2, wherein the flange defines at least one primary apermre for allowing a primary flow of liquid through the passage and at least one auxiliary apermre for allowing an auxiliary flow through the passage, the primary flow of fluid through the passage being interrupted by the valve closure members closing

SUBSTT╬ôL╬á╬ê SHEET (RULE 26) under a suction applied to the drive unit, the suction on the valve closure members being broken by the auxiliary flow of fluid through the passage causing the valve closure members to open, propulsion of the pool cleaning device being caused by the repetition of this cycle.

4. A drive unit according to claim 2 or claim 3, wherein the flange is fixed to the body with the valve closure members extending towards the inlet.

5. A drive unit according to any one of claims 2 to 4, wherein an elongate mbular member extends along the passage from the primary apermre of the flange towards or through the outlet, the mbular member dividing the passage into a primary passage extending through the mbular member to allow for the primary flow of fluid, and an auxiliary passage along the outside of the mbular member to allow for the auxiliary flow of fluid.

6. A drive unit according to any one of the preceding claims, wherein the valve closure members are biased into the open position.

7. A drive unit according to claim 6, wherein the valve closure members are formed of a resilient plastics material so as to be biased into the open position.

8. A drive unit according to any one of the preceding claims wherein the respective valve closure members define opposed sealing edges or faces to provide a tight seal in the closed position.

SUBSTrrUTE SHEET (RULE 26)

9. A drive unit according to claim 8, wherein opposed inserts are provided at or adjacent the opposed sealing edges or faces, the inserts being formed of a generally softer resilient material than that of the valve closure members so as to wrap around any foreign object(s) lodged between the opposed sealing edges or faces in the closed position to ensure that a tight seal is achieved.

10. A drive unit according to any one of the preceding claims, wherein the body includes a housing defining a generally hollow chamber in which the fluid control valve arrangement is located.

11. A drive unit according to claim 10, wherein the valve arrangement divides the chamber into a primary chamber in fluid communication with the primary flow passage and an auxiliary chamber in fluid communication with the auxiliary flow passage, a reduction in pressure in the primary chamber causing the valve closure members to close whilst a reduction in pressure in the auxiliary chamber causes the vacuum in the primary chamber to be broken, allowing the valve closure members to open.

12. A drive unit according to claim 11 , wherein the housing includes control means for controlling the movement of the valve closure members.

13. An automatic pool cleaning device for cleaning a submerged surface, the device comprising:

a body having an inlet arranged to be disposed proximate to the submerged surface to be cleaned, an outlet including

SUBSTTTUTE SHEET (RULE 25) connection means for operative connection to a flexible suction hose, and a passage defined between the inlet and outlet to allow liquid to be drawn therethrough by suction applied to the outlet: and

14. A pool cleaning device according to claim 13, wherein the drive unit is as defined in any one of claims 2 to 12.

15. A drive unit substantially as herein described with reference to the accompanying drawings.

16. A pool cleaning device substantially as herein described with reference to the accompanying drawings.

SUBSTTTUTE SHEET (RULE 26)