EP2150662A1

EP2150662A1 - Steering control and timing device for an automatic pool cleaner

Info

Publication number: EP2150662A1
Application number: EP06760888A
Authority: EP
Inventors: Wieslaw Niewiarowski
Original assignee: KK Australia Pty Ltd
Current assignee: KK Australia Pty Ltd
Priority date: 2005-07-20
Filing date: 2006-07-20
Publication date: 2010-02-10
Anticipated expiration: 2026-07-20
Also published as: PT2150662T; ES2664371T3; WO2007009186A1; EP2150662A4; EP2150662B1

Abstract

A steering control device (1) for an automatic pool cleaner, including a steering mechanism with drive means (12, 17, 21) for operatively steering the pool cleaner, and a control means for timing a change of steering direction of said device. The control means has an input (7) switchable between a first position controlling a first steering direction of said pool cleaner and a second position controlling a second steering direction of said pool cleaner. The steering mechanism includes an output means (20, 22a, 23a) to switch the input means (7) alternately from one of said first or second positions to the other of said corresponding second or first positions. One or more annular rings (22, 23) and/or the number and position of timing teeth (22a, 23a) may be provided to vary reversal timing. A delay mechanism (34, 35a, 35b) may also be included which can be adaptable to effectively disengage the steering mechanism for a period on reversal of the input means (7) to allow the pool cleaner a period of free running.

Description

STEERING CONTROL AND TIMING DEVICE FOR AN

AUTOMATIC POOL CLEANER TECHNICAL FIELD

The present invention relates to automatic pool cleaners, for example, 5 automatic pool cleaners of the type described by Australian Patent Nos. 490972 and 505209, and also Australian Patent Application No. 2002238301 , all of which are included herein by reference. In particular, the present invention relates to arrangements and methods of operation, which may be implemented to control steering of an automatic, pool cleaner.

10 BACKGROUND OF THE INVENTION

Automatic pool cleaners typically include a driven pool cleaner head powered by a suction source connecting the pool cleaner head via a vacuum

^~hose to the suction side of a pool water filtration system. The pool cleaner head may include a housing carried on wheels or tracks for rolling movement along a

15 submerged pool surface or numerous resilient feet which provide a ratcheting forward motion by rocking the cleaner body or by mechanically rocking a number of spring loaded feet. Alternatively, the cleaner head may include a seal

_,.: arrangement sealing a suction zone, which is in fluid communication with a valve chamber, to the submerged pool surface. In either case, debris intake is taken in

20.. via an inlet at a lower end of the housing, in close proximity, with the pool surface, and communicates through a valve chamber or turbine chamber in the housing to the vacuum hose for water-borne vacuuming of debris from the submerged pool surface. Typically, the flow of water drawn by the vacuum hose through the submerged housing is used to power a drive train to, in one example, rotatably

25 drive the cleaner wheels or tracks together with a downward vacuum force for improved traction, or, to drive a valve system to operate, for example, an oscillating flap valve to create a series of water hammer impulses, or rocking action, which ultimately drive the pool cleaner across the submerged pool floor and/or walls. However, any change of direction or steering to randomize cleaning

30 of the pool surface and prevent the cleaner from continuously cleaning the same section or getting stuck in a comer, is determined in such systems by the direction of inclination of the pool surface, gravity, and/or drag due to the connecting hose. One example of a known wheel driven pool cleaner provides a turbine which is rotatably driven by the flow of water drawn through a turbine chamber via the vacuum hose. The turbine is used to power a drive train to rotatably drive cleaner wheels, and also to produce a downward vacuum force for improved wheel traction. In addition, the single turbine driven drive train operates a timer cam for periodically actuating a reverse clutch assembly to drive at least one of the cleaner wheels in reverse. Such arrangements have considerable inherent frictional drag in the drive train created by the large number of drive gears needed to transfer drive motion from the turbine to the wheels, and also at the same time, operate the cam mechanism for timing of the change of direction (turning).

An alternative type of drive mechanism known to the Applicant utilizes three turbines. A first turbine actuates the drive mechanism for forward motion of the housing along the submerged pool floor or walls, a second turbine rotates ihe,. cleaner alternately clockwise or anti-clockwise, and a third turbine acts as a timer ,;.. for periodically reversing the clockwise - anti-clockwise motion of the housing. v Such a mechanism operates by having continuously spinning turbines operated . by the flow of water via the suction hose. Water is drawn through the suction cleaning port to,, cause the cleaner to turn in a chosen direction. : The third, smaller, timing turbine is connected to a timing disk having two timing ports, - which ports sequentially line up with one or other of the main drive ports. The_, changing position of the timing disk and its associated ports, driven by the timing turbine, determines the direction of rotation of the housing relative to the hose, and therefore the direction of forward motion i.e., controls turning. Such mechanisms are known to be overly complex in requiring three separate turbines, which draw considerable power from the flow of water thereby reducing the amount of power available for suction and effective cleaning of the pool surface. Also, timing of the turning action is determined by the flow rate of water being drawn through the device.

An alternative known system provides forward drive via a flap valve creating a series of water hammer impulses to drive the pool cleaner across the pool floor and walls. The steering direction of the pool cleaner head is determined by a separate drive means driven by a one-way ratchet system. The one-way ratchet provides drive to a series of gears and drive shafts, which in turn operates of pair of planetary gears. Each planetary gear has corresponding teeth over approximately 180 degrees of its periphery, and out of phase with the corresponding teeth on the 180 degrees periphery of the other of the planetary gears. Subsequently, when one planetary gear is driven by the one-way ratchet 5 mechanism, the pool cleaner head rotates to move the cleaner in one direction across the pool floor or wall, the other of the planetary gears not being driven. However, since the planetary gears rotate counter to each other, i.e., one rotating clockwise the other rotating anticlockwise, when the teeth of one of the planetary gears and the teeth of the other of the planetary gears take up with gearing to 0 turn the head, the cleaner swivel head connection to the hose reverses to rotate the head in the other direction. The head always moves forward but turns as it does so, first to the left and then right, then left etc. Thus, the ratchet and

% planetary gear mechanism provides a timing device .for timing the change in ^: turning of the cleaner head. Such change of direction is determined by the 5 number of oscillations of the flap valve. Again, although this mechanism has

-■^■ -been found to be efficacious in-timing the, change of turning; drag through the relatively complicated arrangement of gears and shafts draws power from the water flow and therefore reduces vacuum power_available for cleaning. Also, drag in the one-way ratchet mechanism can potentially effect operation of the flap 0 valve, thereby reducing power ..available for the . forward drive movements. In addition, timing of the turning action is determined by the number of oscillations of the flap valve working the one way ratchet.

In the aforementioned known prior art devices, change of the direction of travel is determined by a set time period or the flow rate or number of movement 5 actions, such as oscillations of a flap valve.

With regard to the aforementioned prior art devices, it has further been noted that such devices are generally configured to travel in a straight line unless acted upon by external forces such as drag due to the trailing suction hose or by a timed turbine driven turning device, or the cleaning device meeting a corner or 0 the water surface and subsequently a flotation device operating to effect a change of direction of the cleaner. With the aforementioned in mind, it is an object of the present invention to provide improved steering control for an automatic pool cleaner which alleviates one or more problems associated with the aforementioned prior art devices. SUMMARY OF THE INVENTION With the aforementioned in view, in one aspect of the present invention there is provided a steering control device for an automatic pool cleaner, the device including: a steering mechanism having a drive means for operatively steering a direction of travel of the pool cleaner, and a control means for timing a change of steering direction of travel of said device, said control means including an input switchable between a first position controlling a first steering direction of said pool cleaner and a second position controlling a second steering direction of said pool cleaner, and wherein said steering mechanism includes an output means arranged to switch the- input means alternately from one of said first or second positions to the other of said corresponding second or first positions. Thus, advantageously, the present invention may provide "closed loop" control for steering an automatic pool cleaner, whereby a change of direction of the pool cleaner is determined by the steering mechanism itself, rather than external factors such as the drive means for propelling the pool cleaner. Also, it will be appreciated that timing of change of direction may be determined independent of real time, water flow, or number of turn direction_^motivation actions. Furthermore, closed loop control may be used to set a predetermined number of left and right, or clockwise and anti-clockwise, angular degrees of steering movements.

Thus, one or more forms of the present invention may provide higher operating efficiency than known devices. In addition, one or more forms of the present invention may provide an advantage of the same number of clockwise and anti-clockwise rotations, thereby helping to ameliorate coiling of the suction hose connecting the pool cleaner to the suction pump.

Preferably, the input means may be toggled alternatively between said first and second positions by said output means, such that the steering direction of the device may be alternately changed from one direction to another without requiring additional external input. Preferably, the steering device may be a unitary device, such as an accessory for a poo! cleaner, arranged to be connected as a discreet unit between existing automatic pool cleaner and corresponding suction hose. However, it will be appreciated that the steering device may form part of the 5 automatic pool cleaner. Thus, the unit may be a discrete device for attachment/detachment to a hose and c⁾eaner head. However, the steering device may be incorporated in to a body or housing of the automatic pool cleaner and the hose attached thereto.

Preferably, the steering device may be operated by a portion of the flow of

10 water created by the vacuum side of a pool pump or similar device, the flow of water travelling from an intake side of the automatic pool cleaner to an outlet, usually at a hose connection, to the pump. Thus, power for the steering device may be provided without requiring an external power supply, and is generated by the suction from the pump. Preferably, the portion of water flow for operating the

15 device may be used to rotate a turbine or paddle wheel, which may preferably be used to drive a series of gears, such as reduction gearing to reduce a high rotation rate of the turbine or paddle wheel to a lower number of rotations at a

— final drive gear. The system of gears may be used to drive the steering mechanism. For example, the final drive gear may be used to drive an annular

.20 ring gear forming part of the steering direction device, which may be attached to the suction hose. The turbine or paddle wheel may be rotatably attached to a base portion, which portion may be attached with respect to an automatic pool cleaner and arranged for relative rotation with respect to the annular ring gear attached to the suction hose. Whereby, rotation of the turbine or paddle wheel,

25 through the system of reduction gears, may provide drive to an annular ring gear attached to the suction hose and thereby a base portion of the steering direction device rotates with respect to the annular ring gear portion to provide relative rotation between the suction hose and the automatic pool cleaner thereby providing a change in steering direction through relative rotation.

30 Preferably, the portion of flow of suction may be directed through the base portion of the steering direction device to provide drive to the turbine or paddle wheel. Outflow from the turbine or paddle wheel may be redirected to the bulk of the flow to the vacuum hose. That is, the output flow from the turbine or paddle wheel is returned to the main flow. Such return may be via a venturi or other means for creating a negative pressure in the output side of the turbine or paddle wheel. The negative pressure side of the turbine or paddle wheel may be formed in the throughput flow of vacuum passing through the device to the vacuum hose. The switchable input my be used to change the direction or flow path of the proportion of flow used to drive the turbine or paddle wheel, thereby effecting a reversal in the direction of rotation of the turbine or paddle wheel. Thus, the steering direction may be reversed or the path directed by the steering device changed from one direction to another direction. Preferably, the switchable input effects positions of a flow valve to thereby redirect flow to the turbine or paddle wheel from one path to another. The flow valve may provide different sized flow channels for driving the turbine or paddle wheel in one direction or another. Different sized flow channels may, provide different rates of flow or pressure to operate the steering mechanism. For example, a flow channel of small diameter or width through one direction of a flow valve may provide high speed flow to the

> ' turbine or paddle wheel, thereby effecting a relatively short time period for the change in steering direction, and a second channel in the flow valve may be of greater width or diameter to thereby provide a lower rate of flow to the turbine or paddle wheel, though potentially a greater volume of flow providing high torque. This lower flow rate effects a reduction in the rotation rate of the turbine or paddle wheel thereby effecting a longer time period until the change of steering direction.

Preferably, the switchable input may be used to toggle a flow valve between a first position commensurate with a first position of the switchable input, and a second position commensurate with a second position of the switchable input.

More preferably, the switchable input is a toggle switch connected to the flow valve via a biasing means, such as a leaf or torsion spring. However, it will be appreciated that other arrangements of connection are considered to fall within the scope of various embodiments of the present invention. According to one or more forms of the present invention, an output means may be used to toggle the input means between first and second positions. Preferably, the output means is provided on or adjacent the periphery of a portion of the steering mechanism connected to the aforementioned annular ring gear. Thus, relative rotation of the annular ring gear driven by the drive means may be used to pause the output means to toggle the switchable input means such that a direction of operation of the drive means is reversed, for example, by the input means toggling a flow valve to reverse direction of the turbine or paddle wheel. Preferably the annular ring gear is connected to the substantially circular ring portion having a projecting tooth portion. The tooth portion may engage with a toggle switch forming the input means.

Preferably, the water flow input into the device from the total water flow is passed through an inlet filter to help prevent debris or dirt entering the device and causing subsequent damage, wear and tear or stoppage of the device.

Thus, timing of operation between switching of the switchable input from the first or second position to the corresponding second or first position may be

■:■^• determined by the rate of relative rotation between the output means,, e.g., in the form of a projecting tooth, and the input means provided on the base portion of the device. Preferably, the output means is provided as a single projection. However, it will be appreciated that the number_ of. spaced projections may be provided as the output means, such that the timing of relative rotation from one switching event to the subsequent switching event, may .be extended and/or varied and/or reduced. Furthermore, whilst various forms of the present invention may include the output means directly acting on the input means, e.g., by relative rotation, it is envisaged that additional output to input transfer means may be provided. These may be provided between the original output and input means, so that a selected number of sequential output to input operations are carried out between the first output means and the final input means. Thus, additional timing delays can be designed into the device by selecting the number of desired additional output to input operations. The timing delay in one turning direction eg clockwise, may be equal or unequal to a corresponding timing delay in another direction eg anticlockwise. The additional output to input means may take the form of one or more annular rings having, on one portion of each ring, at least one subsidiary input means for operation by the output means and at least one subsidiary output means for cooperating with further at least one subsidiary input means or the final input means. Thus, the period between the output means operating the input means can be put in place by varying a number of intermediate output to input transfer means and/or the number and/or position of the subsidiary output and subsidiary input means on each intermediate transfer means. Thereby, one or more embodiments of the steering direction device according to the present invention may provide timing means for timing the change of steering direction of the device.

Thus, the pool cleaner head may drive itself along whilst at the same time travelling in an arc to the left or right (due to a turning motion) with respect to a forward direction of travel. The device according to the present invention may determine, independent of real time, number of oscillations of a flap valve or rotations of a turbine, when the pool cleaner changes from one turning direction to another turning direction eg from travelling in, say, an arc to the left to an arc to the right, and vice versa.

A further aspect of the present invention provides a steering control device for an automatic pool cleaner, the device including a control means for timing a change of. steering direction of said device, said control means including an input switchable between a first position controlling a first steering direction of said pool cleaner, and a second position controlling a second steering direction of said pool cleaner, wherein said switchable input is arranged to switch a drive means between the first drive direction and a second drive direction, said drive means having an output adapted to switch the input means from said first of second position to the other or said first or second positions.

Preferably, said drive means steers a direction of travel of the pool cleaner and said control means may vary the timing of the change of steering direction of said device and/or a rate of change of steering direction.

Preferably the present invention may include at least one intermediate timing means, such as annular rings. One or more such timing means may include means to permit water flow into the device, such as by providing apertures spaced around the periphery of at least one said intermediate timing means. Such water flow may be used to power the timing device eg to drive a paddlewheel or turbine. Preferably the apertures may be formed as slots or channels through the periphery of the at least one intermediate timing means, for example, forming a consecutive series of channels and projections around the circumference. Given the relative long length of the periphery of the intermediate timing means, and the relatively small amount of flow required to drive the device, only a low pressure flow through the channels may be required. Thus, the apertures are less likely to attract dirt etc which may otherwise clog or block up the apertures. The channels thus may act as a filter, which can obviate or reduce the need for an intake filter elsewhere on the device, such as on the underside of the base.

Rotation of one intermediate timing means relative to another timing means or other portion of the device (top or base etc) may provide a self cleaning function to help maintain the apertures clear and open eg effected by edges of the slots wiping an adjacent surface of another portion of the device, such as an adjacent surface of another intermediate timing means during relative rotation of one timing means with another. The apertures may provide just enough leakage of water flow into the device over a sufficiently large area (i.e., low pressure intake) to avoid or reduce intake of dirt whilst allowing sufficient flow to power the device.

To assist further randomising motion of a pool cleaner, the device may include delay means to disengage or delay the timing, action whilst the device remains operating. For example, whilst the pool cleaner is operating and the timing and steering device is functioning, the device may include delay means to. postpone or temporarily delay changes in the direction of rotation left or right steering of the pool cleaner (thereby allowing the pool cleaner to travel straight on rather than a curved path). This function may also permit a delay in the timing of reversal from left to right or vice versa. The delay means may operate by temporarily disengaging or preventing relative rotational motion between the device and the vacuum hose to the pump despite any other timing action remaining operational. For example, although the device may ordinarily be set to allow three left or right turns of the pool cleaner before reversing to right or left, the delay means may allow between 0 and almost 360 degrees (preferably 0 to approximately 350 degrees) of freewheeling before timing takes effect. Thus, although the intermediate timing rings, say, may provide for three complete turns before reversing takes place, the delay means may effectively remove between zero and one of those turns. Preferably the delay means may be adjustable to operate between predetermined minimum and maximum values e.g., by insertable stops.

More preferably, the delay means may be provided by interaction between at least one projection, such as one or more pegs, and a recess in a collar or flange. For example, the at least one projection may be provided on an upper surface of the device, and the recess may be provided in a collar or flange connected to the vacuum hose, the collar/flange and the protrusion(s) being arranged for relative rotation (eg during turning of pool cleaner).

The protrusion(s) (e.g., peg(s)) may be insertable into apertures provided in the device, thus allowing variable adjustment of operation of the delay means. An alternative embodiment envisages retractable protrusions which may be retracted or extended as appropriate to effect a pattern of delay.

It will be convenient to further describe the present invention with respect to the accompanying drawings which illustrate possible arrangements of the steering control device according to the present invention. Other arrangements of the invention are possible, and consequently, the peculiarity of the accompanying drawings is enough to be understood as superseding the generality of the preceding description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an interior view of part of a device according_, to an embodiment of the present invention displaying a turbine/paddle wheel, flow control valve, and input means.

Figure 2 shows an interior view of part of a device according to an embodiment of the present invention shown in Figure 1 , and further including a series of reduction gears for transferring rotational drive from the turbine/paddle wheel to an output gear.

Figure 3 shows an exploded perspective view of an embodiment of the present invention including intermediate output to input timing transfer means.

Figure 4 shows a partially exploded perspective view of embodiment of a self clean and filter arrangement for the device

Figure 5 shows a plan view of a disengaging (clutch) mechanism for an embodiment of the present invention.

Figure 6 shows a side view of the mechanism of Figure 5. DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 shows a base portion 2 of a unitary arrangement of the steering direction device 1 according to an embodiment of the present invention. The base portion 2 is generally circular having a peripheral wall 4 around the periphery of a generally disk like base plate 5. Through approximately the centre portion of the base plate 5 passes the lumen of a water flow aperture 6. In the arrangement shown in Figure 1 , water flow would typically pass up through the aperture to the suction or pump side of the device. The base portion 2 houses a toggle switch 7 providing the switchable input means. The toggle switch 7 is connected via a leaf spring 8 to a flow control valve 9. In the particular arrangement shown in Figure 1 the toggle switch 7 is shown holding the flow control valve 9 biased towards a wall portion 10 of a paddle wheel chamber 11 housing a paddle wheel 12 for driving the steering direction mechanism. With the flow control valve 9 biased towards the wall portion 10, part of the water flow diverted from the main water flow, enters the device by a filter and opening 13. The partial water flow is directed through the flow channel created between the flow control valve 9 and wall portion 14 whilst the flow control valve 9 is biased away from wall portion 14. In the arrangement shown in Figure 1 , the paddle wheel 12 is driven to rotate anti-clockwise by the flow of water passing through flow channel 15. It will be appreciated that, when the toggle switch 7, which acts as the input means, is operated to its second position, the flow control valve is biased away from wall portion 10 towards wall portion 14 to thereby close flow channel 15 and open flow channel 16. The leaf spring 8 acts to maintain the flow control valve 9 biased in the selected first or second position until the toggle switch is operated in the opposite direction to move the control valve to its opposite position. Water flow in to the paddle wheel chamber 11 is allowed to escape and rejoin the central main flow through the aperture 6, in the arrangement shown a venturi providing reduced or negative pressure to thereby assist in pulling the partial flow of water through the paddle wheel chamber and thereby enhance flow and power characteristics within the device.

Figure 2 shows a similar arrangement to the embodiment shown in Figure 1 , though with a series of reduction gears rotatably connecting the paddle wheel 12 to a main output gear 17. The series of reduction gears helps to reduce the relatively fast spinning paddle wheel 12 to a more useful low speed (and relatively high torque) rotation at the main output gear 17. It will be appreciated that operation of the toggle switch 7 to its second position, which thereby sets the control valve 9 to its opposite position will allow water flow to pass through slow channel 16 to effect rotation of the paddle wheel 12 in a clockwise direction, thereby reversing the direction of rotation of the output gear 17. Further operation of the toggle switch 7 to its original position will again reverse the direction of rotation of the paddle wheel 12 and thereby reverse the direction of rotation of the output gear 17. Figure 3 shows an exploded perspective view of a unitary form of the steering control device according to an embodiment of the present invention. In particular, the base portion 2 is shown as an underneath perspective view of the base portions 2 shown in Figures 1 and 2. The toggle switch 7 providing the switchable input means of the present invention is shown protruding to the peripheral side wall of the base portion 2. The filter and inlet 13 is shown to the right of the main through flow aperture 6. Arrows A-A show the direction of through flow of the main flow of water passing from the suction surface against the pool to the suction or pump side of the device 1. In the embodiment shown in Figure 3, the device 1 is a unitary arrangement for connection as a unit between the suction hose 18 and the head of an automatic pool cleaner (not shown). However, it will be appreciated that further or additional embodiments of the present invention may be incorporated into or as part of the cleaning head of an automatic pool cleaner.

Upper portion 3 is arranged for connection, direct or indirectly, to base portion 2, provided relative rotation between the upper portion 3 and the lower portion 2 is maintained. Upper portion 3 includes an outer peripheral wall 19 having a tooth 20 arranged to effect operation of the toggle switch 7 or interact with optional intermediate timing rings. Upper portion 3 further includes an internal annular ring gear 21 arranged for engagement with the main output gear 17 shown in Figure 2. Thus, drive from the paddle wheel 12, transmitted via the series of reduction gears to the main output gear 17 is transferred via the output gear 17 to the upper portion 3 of the device via the annular ring gear 21 , thereby providing powered and reversible relative rotation between the upper portion 3 and the base portion 2 of the device. Whilst upper portion 3 and lower portion 2 may be connected directly together. That is, so that output tooth 20 effects direct operation of toggle switch 7. However, as shown in Figure 3, additional intermediate secondary output to input means can be provided. Thereby, as upper portion 3 rotates relative to base portion 2, the output tooth 20 is arranged to engage the corresponding input portion on the first intermediate ring 22 thereby causing intermediate ring 22 to rotate in the same direction as the upper portion 3 and correspondingly counter to relative rotation of base portion 2. An output tooth 22a of ring 22 will eventually engage the corresponding portion on intermediate ring 23, causing intermediate ring 23 to rotate in concert with upper portion 3 and intermediate ring 22. Eventually, an output tooth 23a of intermediate ring 23 will engage with toggle switch 7 to thereby effect a reversal of the direction of rotation of the paddle wheel (as previously mentioned) to thereby commence relative rotation of the upper portion with respect to the base portion in the opposite direction, and thereby recommencing the engagement stages of the relevant output teeth 20, 22a and 23a with their corresponding engagement portions.

It will be appreciated that, in the absence of any intermediate rings, and only having a single output tooth 20 on upper portion 3, that relative rotation of the upper portion to the base portion would be almost 360 degrees (taking into account the width of output tooth 20 and operating distance of toggle switch 7). That is, relative rotation in reality, in the embodiment shown, will be approximately 360 degrees minus 10 degrees operating requirements. However, it should be further appreciated that upper portion 3 may have two output teeth 20a and 20b separated by a predetermined angular distance around the periphery. This angular separation may be adjustable to provide controlled timing of reversal of the steering direction. Furthermore, intermediate rings, such as 22 and 23, may also have additional input elements or output elements, such as teeth 22a and 23a, possibly separated by an angular distance on each ring, such that timing of the reversal of operation of the steering device can be preselected and/or changed when required. Thus, the timing of a change of direction of the automatic pool cleaner can be predetermined independent of real time, number of forward motivation pulses and oscillations, and cam or ratchet mechanisms. Furthermore, the rate of rotation of the upper portion relative to the base portion can be varied either to be clockwise or counter-clockwise, or both, directions by adapting the relative sizes of the flow channels 15 and 16 defined by the flow control valve 9 and side wall portions 10 and 14. Thus, not only can the number of rotations of the head of the automatic pool cleaner relative to the suction hose before a reversal of rotation direction is effected be determined by the number and position of the output teeth, but also the rate at which relative rotation occurs can be controlled. To this end, randomization of the travel path of the automatic pool cleaner head can be greatly enhanced to thereby provide increased coverage and likelihood of debris removal, whilst helping to avoid retracing a previously cleaned path of travel.

With regard to the intermediate rings 22 and 23 shown in Figure 3, since each ring adds approximately 360 degrees minus 10 degrees of rotation before operation in either direction, delay to operation of the toggle switch 7 is approximately 350 degrees for the upper portion 3 plus 350 degrees for each additional ring. Thus, with respect to the embodiment shown in Figure 3, the head of the automatic pool cleaner will rotate relative to the suction hose approximately 350 degrees times three, equals 1,050 degrees (or nearly at least three complete revolutions) before the toggle switch 7 is operated and the relative rotation is reversed. Actuators on the annular rings can vary in relative position so that each ring may provide a different or the same or additional annular timing actuation. For example, a first annular ring may provide 300 degrees timing, whilst at a second ring provides 100 degrees timing and third ring 300 degrees again, thereby totalling 700 degrees rotation before the toggle is operated. It will be appreciated that a variety of choices of rotational degrees can be selected by choosing the appropriate number of rings and position(s) of actuator(s) thereon. Thus, the device can be arranged to, not only control the number of revolutions of the pool cleaner head before steering direction is reversed, but also any variation of the flow channels passing the flow control valve within the device can be used to vary the radius of travel of the head of the pool cleaner. For example, a larger flow channel reduces flow of water to the paddle wheel, thereby slowing rotation of the paddle wheel and resulting in a greater radius of curvature of travel path. A decreased width of flow channel increased the speed of the flow to that channel and thereby increases the speed of the paddle wheel, which results in a smaller radius of travel path.

Figure 4 shows the device 1 partially exploded and including a series of raised portions 30 around the upper periphery of the base portion 2 arranged to wipe around the underside of the ring or cover above. In the embodiment shown, the raised portions wipe against the ring 23 immediately above. Consequent to the raised portions are formed channels (grooves or slits) 31 around the periphery. The channels act as filter openings to allow water flow to enter the device to drive the turbine. The large number of channels spread around the periphery allows a relatively high water flow at low pressure, thereby helping to restrict ingress of dirt. In addition, relative rotation of the channels compared to the adjacent surface on which the ring or base rotates (ie the next ring or other portion) sweeps dirt from the channels, thereby providing a self cleaning filter function. Gear ratios between the turbine and output could be varied such that the rate of rotation, and therefore different timing rate and steering rate, may be adopted. This will be particularly useful where the device is adopted for use as a retrofit or aftermarket part for a pool cleaner, say by a different supplier.

Because of the adaptability of the timing mechanism, various combinations of timing rings and delay may be adopted, thereby providing a unique device which is adaptable to suit many pool designs and styles, including rectangular, kidney shaped and irregular pools. The steering device can be adjusted through selecting suitable combinations of top part, base and timing rings, spacing of input and output means on each ring/base/top part and, if provided, through the arrangement of projections and flange etc on the delay means.

Figure 5 shows a plan view of the device 1 including a delay means. In use, a hose would be attached to a spigot 33 rotatable freely with respect to the rest of the device but only within predetermined bounds. The spigot includes a flange 34 which may extend around the spigot to a greater or lesser degree than shown. Rotation of the flange is limited by stop means 35a and 35b. During operation, the top cover of the device is driven by the turbine and gearing. The hose and top cover is either disengaged with respect to the hose (during freewheeling) in order to rotate with the rest of device. Thus, with the device effectively disengaged from rotation with respect to the hose (except for the top cover) the pool cleaner is not forced to turn left or right, rather will naturally travel a generally straight line unless the pool surface dictates otherwise (eg wall or sideways slope). When the stop means and flange engage, the top cover remains static with respect to the hose and the remainder of the timing mechanism and thus pool cleaner can rotate, may be arranged to allow three rotations before reversing. However, the delay means may effectively "take out" the effect of part or nearly all of one timing rotation by allowing freewheeling of the pool cleaner. The pool cleaner can then travel in a straight line for the disengaged period of the steering device. Thus, the delay means may act as a "clutch" to temporarily disengage the device from rotation with respect to the hose. Once the spigot of the device rotates sufficiently, the stop means running re-engages with a portion of the flange and consequently timing is again effective. In this way, say three rotations through the annular timing rings can be reduced by a period of straight running of the pool cleaner for up to nearly one turn (thus resulting in two turns within a period normally for three turns).

Figure 6 shows a side view of the embodiment shown in Figure 5. This improves random action of the pool cleaner, which would otherwise have a continual reversing "S" shaped path, by introducing a period of 'freewheeling" for the pool cleaner (essentially disconnected for a period from the steering effect of the device to allow straight travel). It will be appreciated that the flange may be a channel or recess and the stop means may operate within the channel or recess. In addition, the stop means may be movable or adjustable to be selected for operation or not, as required.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A steering control device for an automatic pool cleaner, the device including: a steering mechanism having a drive means for operatively steering a direction of travel of the pool cleaner, and a control means for timing a change of steering direction of travel of said device, said control means including an input switchable between a first position controlling a first steering direction of said pool cleaner and a second position controlling a second steering direction of said pool cleaner, and wherein said steering mechanism includes an output means arranged to switch the input means alternately from one of said first or second positions to the other of said corresponding second or first positions.

2. A steering control device for an automatic pool cleaner, the device including a control means for timing a change of steering direction of said device, said control means including an input switchable between a first position controlling a first steering direction of said pool cleaner, and a second position controlling a second steering direction of said pool cleaner, wherein said switchable input is arranged to switch a drive means between the first drive direction and a second drive direction, said drive means having an output adapted to switch the input means from said first of second position to the other or said first or second positions.

3. A steering control device as claimed in claim 1 or 2, wherein the input means is arranged to be toggled alternatively between said first and second positions by said output means, whereby steering direction of the device is alternately changed from one direction to another without requiring additional external input.

4. A steering control device as claimed in any one of the preceding claims, wherein the device is a unitary device, such as an accessory for a pool cleaner.

5. A steering control device as claimed in any one of the preceding claims arranged to be connected as a discreet unit between existing automatic pool cleaner and corresponding vacuum hose.

6. A steering control device as claimed in any one of the preceding claims wherein the steering device is operated by a portion of the flow of water created by a pump or similar device, the flow of water travelling from an intake side of the automatic pool cleaner to an outlet, usually at a hose connection, to the pump.

7. A steering control device as claimed in claim 6, wherein a portion of water flow through the device is used to rotate at least one turbine or paddle wheel to power the device.

8. A steering control device as claimed in claim 7, wherein the at least one turbine or paddlewheel is used to drive the device through a series of gears, such as reduction gearing to reduce a high rotation rate of the turbine or paddle wheel to a lower number of rotations, to a final drive gear.

9. A steering control device as claimed in any one of the preceding claims, wherein a drive gear is used to drive a ring gear connected to the suction hose, and a pool cleaner is connected to a base portion of the device, the base portion and the hose arranged for relative rotation to permit steering of the pool cleaner .

10. A steering control device as claimed in claim 9, wherein the at least one turbine or paddle wheel may be rotatably connected to the base portion, which portion may be attached with respect to an automatic pool cleaner and arranged for relative rotation with respect to the annular ring gear attached to the suction hose, whereby, rotation of the turbine or paddle wheel, through the system of reduction gears provides drive to the annular ring gear connected to the suction hose and thereby a base portion of the steering direction device rotates with respect to the annular ring gear portion to provide relative rotation between the suction hose and the automatic pool cleaner thereby providing a change in steering direction.

11. A steering control device as claimed in any one of the preceding claims, wherein a portion of water flow through the device is directed to power the device.

12. A steering control device as claimed in any one of the preceding claims wherein a water outflow from a means to power the device is redirected to the remaining bulk of cleaning water flow to the vacuum hose.

13. A steering control device as claimed in claim 12 , wherein redirected flow is effected via a venturi or other means for creating a negative pressure in the output side of the means to power the device.

14. A steering control device as claimed in any one of the preceding claims when dependent upon claim 7, wherein the switchable input is used to change the direction or flow path of the proportion of flow used to power the at least one turbine or paddlewheel, thereby effecting a reversal in the direction of rotation of the turbine or paddle wheel.

15. A steering control device as claimed in claim 14, wherein the switchable input effects positions of a flow valve to thereby redirect flow to the at least one turbine or paddle wheel from one path to another.

16. A steering control device as claimed in claim 14 or 15, wherein the flow valve includes different sized flow channels for driving the turbine or paddle wheel in one direction or another, the different sized flow channels providing different rates of flow or pressure to operate the steering mechanism at different rates left or right.

17. A steering control device as claimed in any one of the preceding claims, wherein the switchable input is used to toggle a flow valve between a first position commensurate with a first position of the switchable input, and a second position commensurate with a second position of the switchable input.

18. A steering control device as claimed in claim 17, wherein the switchable input includes a toggle switch connected to the flow valve via a biasing means, such as a leaf or torsion spring.

19. A steering control device as claimed in any one of the preceding claims, wherein an output means is used to toggle the input means between first and second positions.

20. A steering control device as claimed in claim 19, wherein the output means is provided on or adjacent a periphery of a portion of the steering mechanism whereby, relative rotation of an annular ring gear driven by the drive means causes the output means to toggle the switchable input means such that a direction of operation of the drive means is reversed.

21. A steering control device as claimed in claim 20, wherein the annular ring gear is connected to a substantially circular ring portion having a projecting portion.

22. A steering control device as claimed in claim 21 , wherein the projecting portion is arranged to engage with a toggle switch forming the input means.

23. A steering control device as claimed in any one of the preceding claims, wherein water flow input to power the device passes through an inlet filter.

24. A steering control device as claimed in any one of the preceding claims, wherein at least one additional output to input transfer means is provided.

25. A steering control device as claimed in claim 24, wherein the at least one additional output to input means is provided between the original output and input means, whereby a predetermined number of sequential output to input operations are carried out between the first output means and the final input means.

26. A steering control device as claimed in claim 25, wherein the at least one additional output to input means is at least one annular rings having, on one portion of each ring, at least one subsidiary input means for operation by the output means and at least one subsidiary output means for cooperating with further at least one subsidiary input means or the final input means.

27. A steering control device as claimed in any one of the preceding claims, further including at least one intermediate timing means, such as the annular rings.

28. A steering control device as claimed in claim 27, wherein one or more such timing means includes means to permit water flow in to operate the device.

29. A steering control device as claimed in claim 28, wherein, such means to permit water flow in to operate the device is provided by at least one aperture around the periphery of at least one said intermediate timing means.

30. A steering control device as claimed in claim 29, wherein the at least one aperture is formed as a slot or channel through the periphery of the at least one respective intermediate timing means, for example, forming a consecutive series of slots and projections around the circumference.

31. A steering control device as claimed in claim 29 or 30, wherein rotation of at least one intermediate timing means relative to another such timing means or other portion of the device provides a self cleaning function to help maintain the at least one aperture open.

32. A steering control device as claimed in claim 31 , wherein the self cleaning function is effected by edges of the channels wiping an adjacent surface of another portion of the device, such as an adjacent surface of another intermediate timing means during relative rotation of one timing means with another.

33. A steering control device as claimed in any one of the preceding claims, including delay means to disengage or delay steering action whilst the device remains running.

34. A steering control device as claimed in claim 33, wherein the delay means temporarily disengages or prevents relative rotational motion between the device and the vacuum hose to the pump despite any other action of the device remaining operational.

35. A steering control device as claimed in claim 33 or 34, wherein the delay means is adjustable to operate between predetermined minimum and maximum values.

36. A steering control device as claimed in any one of claims 33 to 35, wherein the delay means is provided by interaction between at least one projection, such as one or more pegs, and a collar or flange.

37. A steering control device as claimed in claim 36, wherein the at least one projection is provided on an upper surface of the device, and a recess is provided on a collar or flange connected to the vacuum hose, the collar/flange and the protrusion(s) being arranged for relative rotation.

38. A steering control device as claimed in any one of claims 33 to 37, wherein the delay means is adjustable between a minimum and a maximum amount of delay.

39. A steering control device as claimed in claim 37 or 38, wherein the projection(s) is/are insertable into at least one corresponding aperture provided in the device thereby allowing variable adjustment of operation of the delay means.

40. A steering control device as claimed in any one of claims 37 to 39, wherein the at least one projection is retractable and extendable as appropriate to effect a pattern of delay.