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Patent Searching and Data


Title:
A POOL CLEANER
Document Type and Number:
WIPO Patent Application WO/2015/021511
Kind Code:
A2
Abstract:
A pool cleaner (10) has a chassis, drive wheels (14) that engage containment surfaces of a pool and support the chassis above the containment surfaces, and a pair of circular brushes (16). A drive mechanism receives rotational motion from the drive wheels, and is configured to cause the brushes to counter-rotate with rotation of the drive wheels. A receptacle (48) receives detritus that is swept from the containment surfaces by the brushes. A handle (18) is connected to the chassis, and a user grasps the handle to advance the pool cleaner along the containment surfaces, causing the drive wheels to rotate.

Inventors:
ENDRESZ, Matt ("Haven Hill", Howlong RoadSplitters Cree, Albury New South Wales 2640, AU)
SIM, Robert (Level 1, 358 Lonsdale StreetMelbourne, Victoria 3000, AU)
Application Number:
AU2014/050185
Publication Date:
February 19, 2015
Filing Date:
August 15, 2014
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ENDRESZ, Matt ("Haven Hill", Howlong RoadSplitters Cree, Albury New South Wales 2640, AU)
International Classes:
A47L11/16
Attorney, Agent or Firm:
DAVIES COLLISON CAVE (1 Nicholson Street, Melbourne, Victoria 3000, AU)
Download PDF:
Claims:
CLAI S:

1. A pool cleaner including :

a chassis;

one or more wheels that engage containment surfaces of a pool and support the chassis above the containment surfaces, at least one of the wheels being a drive wheel; a pair of circular brushes;

a drive mechanism that receives rotational motion from the or each drive wheel, the drive mechanism being configured to cause the pair of brushes to counter-rotate with rotation of the or each drive wheel;

a receptacle for receiving detritus that is swept from the containment surfaces by the brushes; and

a handle connected to the chassis that a user grasps to advance the pool cleaner along the containment surfaces, causing the or each drive wheel to rotate.

2. A pooi cleaner according to claim 1 , wherein the brushes are inclined such that the forward-most portion of the brushes is lower than the rear-most portion.

3. A pool cleaner according to either claim 1 or 2, wherein the poo! cleaner has two drive wheels.

4. A pool cleaner according to ciaim 3, wherein the drive mechanism is configured to cause rotate the brushes with rotation of either drive wheel 5. A pool cleaner according to any one of claims 1 to 4, wherein each brus is mounted on a brush shaft, and th drive mechanism includes two right-angle gear sets that are each connected to a respective brush shaft, and at least one transverse shaft, and wherein each right-angle gear set is connected to a respective one of the at least one transverse shaft, and the drive mechanism is configured to transfer rotary motion from the drive wheels to the at least one transverse shaft.

6. A pool cleaner according to claim 5, wherein the drive mechanism consists of a single transverse shaft to which both right-angle gear sets are connected.

7. A pool cleaner according to any one of claims 1 to 6, wherein the drive mechanism can include a clutch associated with each drive wheel, such that the brushes only rotate with forward rotation of at least one of the drive wheels. 8. A pool cleaner according to claim 7, wherein the drive mechanism includes:

internal gear teeth arranged on an internal surface of the rim of each drive wheel; a pinion rotatably mounted on one end of a stub shaft, the pinion having gear teeth that mesh with the internal gear teeth such that the pinion rotates with rotation of the respective drive wheel;

wherein the clutch is disposed between each drive wheel and the respective pinion, the clutch being arranged such that the respective stub shaft rotates with forward rotation of the respective drive wheel, and wherein the stub shaft is connected to at least one of the brushes such that the respective brushes rotate with rotation of the respective stub shaft.

9. A pool cleaner according to claim 8, wherein the dutch can include:

a set of ramps formed in an internal recess of the or each pinion, and

a shuttle pin that is disposed in a transverse hole that extends through the respective stub shaft, such that the shuttle pin is free to move in a radial direction relative to the stub shaft,

whereby when the pinion is rotated in the forward direction the shuttle pin engages with a short side of one of the ramps to cause the stub shaft to rotate with the pinion, and whereby when the pinion is rotated in the rearward direction the shuttle pin oscillates within the internal recess by sequential contact with long sides of the ramps such that the pinion freely rotates on the respective stub shaft.

10. A pool cleaner according to claim 9, wherein each pinion has three ramps that are spaced at 120s intervals around the internal recess. 1 1 . A pool cleaner according to claim 10, wherein the drive mechanism further includes a primary ring gear mounted on the or each stub shaft at the opposing end to the respective pinion such that the primary ring gear rotates with the respective stub shaft, each primary ring gear being rotatably connected to a respective secondary ring gear that is mounted on the or each transverse shaft. 12, A pool cleaner according to any one of claims 3 to 11 , wherein the both drive wheels are mounted on a common transverse axle.

13, A pool cleaner according to any one of claims 1 to 12, wherein the drive mechanism is geared such that the rotational speed of the brushes is greater than the rotational speed of the drive wheels.

14, A pool cleaner according to any one of claims 1 to 1.3, wherein the overall gear ratio of the drive mechanism is in the range of 2:1 to 6:1.

15, A pool cleaner according to any one of claims 1 to 14, wherein the overall gear ratio is approximately 4:6:1.

16, A pool cleaner according to any one of claims 1 to 15, having two drive wheels, and wherein the track width of the two drive wheels is approximately the same as the combined width of the brushes.

17, A pool cleaner according to any one of claims 1 to 16, the rotational axis of the brushes is forward of the rotational axis of the at least one drive wheel,

18, A pool cleaner according to any one of claims 1 to 17, further including one o more castors to support the chassis.

19, A pool cleaner according to any one of claims 1 to 18, wherein the handle is connected to the chassis by a pivot that enables the handle to pivot in a transverse direction relative to the forward movement direction of the pool cleaner.

20, A pool cleaner according to any one of claims 1 to 19, wherein the receptacle includes a mesh bag,

21 , A pool cleaner according to claim 19, wherein the receptacle further includes a duct that directs swept detritus into the mesh bag.

22, A pool cleaner according to any one of claims 3 to 11 , further includes an outer housing that forms the chassis of the poo! cleaner.

Description:
A Pool Cieaner

Field of the invention

The present invention relates to a poo! cleaner,

Background

Many domestic pools include a filtration system that removes detritus, such as dirt and leaves, from pool water taken in through a skimmer box. However, these filtration systems are not particularly effective for cleaning the containment surfaces of a pool (the containment surfaces including the walls and floor), or removing detritus that accumulates on these surfaces. For this reason, pool owners use additional cleaning aids to clean their pools. A pool net is often used to scoop leaves and sticks that accumulate in the pool, both at the surface and on the pool floor. Pool nets are slow and are not able to loosen dirt that accumulates on the pool floor. Automated cleaners are available, and these have various drive mechanisms to move the cleaner across the floor and walls of the pool. Although considered to be relatively effective, automated cleaners have some problems, including difficulty in reliably cleaning all areas of the pool evenly, poor performance due to clogging, and difficulty in cleaning particularly dirty pools.

Accordingly, it is desired to address the above, and/o at least provide a useful alternative.

Summary of the invention

The present invention provides a pool cleaner including

a chassis;

one or more wheels that engage containment surfaces of a pool and support the chassis above the containment surfaces, at least one of the wheels being a drive wheel; a pair of circular brushes;

a drive mechanism that receives rotational motion from the or each drive wheel, the drive mechanism being configured to cause the pair of brushes to counter-rotate with rotation of the or each drive wheel; a receptacle for receiving detritus that is swept from the containment surfaces by the brushes; and

a handle connected to the chassis that a user grasps to advance the pool cleaner along the containment surfaces, causing the or each drive wheei to rotate.

The brushes are inclined such that the forward-most portion of th brushes is tower than the rear-most portion. Thus, when the pool cleaner is resting on its wheels, the forward-most bristles contact the supporting surface, and the rear-most bristles are raised above the supporting surface.

In certain embodiments, the pool cleaner has two drive wheels. The drive mechanism can be configured to cause the brushes to rotate with rotation of either drive wheel. Alternatively, the drive mechanism can require rotation of both drive wheels to cause the brushes to rotate.

Each brush is mounted on a brush shaft, and the drive mechanism includes two right-angle gear sets that are each connected to a respective brush shaft, and at least one transverse shaft, wherein each right-angle gear set is connected to a respective one of the at least one transverse shaft, and wherein the drive mechanism is configured to transfer rotary motion from the drive wheels to the at least one transverse shaft.

Preferably, the drive mechanism consists of a single transverse shaft to which both right-angle gear sets are connected. In certain embodiments, the drive mechanism can include a clutch associated with each drive wheel, such that the brushes only rotate with forward rotation of at least one of the drive wheels. Thus, rearward rotation of the drive wheels is not transferred to the brushes. In some embodiments, the drive mechanism includes:

internal gear teeth arranged on an internal surface of the rim of each drive wheel; a pinion rotatably mounted on one end of a stub shaft, the pinion having gear teeth that mesh with the internal gear teeth such that the pinion rotates with rotation of the respective drive wheel;

wherein the clutch is disposed between each drive wheel and the respective pinion, the clutch being arranged such that the respective stub shaft rotates with forward rotation of the respective drive wheel and wherein the stub shaft is connected to at least one of the brushes such that the respective brushes rotate with rotation of the respective stub shaft. in such embodiments, the .clutch can include:

a set of ramps formed in an internal recess of the or each pinion, and

a shuttle pin that is disposed in a transverse hole that extends through the respective stub shaft, such that the shuttle pin is free to move in a radial direction relative to the stub shaft,

whereby when the pinion is rotated in the forward direction the shuttle pin engages with a short side of one of the ramps to cause the stub shaft to rotate with the pinion, and whereby when the pinion is rotated in the rearward direction the shuttle pin oscillates within the internal recess b sequential contact with long sides of the ramps such that the pinion freely rotates on the respective stub shaft.

Preferably, each pinion has three ramps that are spaced at 120 e intervals around the internal recess.

Preferably, the drive mechanism further includes a primar ring gear mounted on the or each stub shaft at the opposing end to the respective pinion such that the primary ring gear rotates with the respective stub shaft, each primary ring gear being rotatabiy connected to a respective secondary ring gear that is mounted on the or each transverse shaft. In this embodiment, both drive wheels are mounted on a common transverse axle.

In some embodiments, each drive wheel is mounted on a stub axle, and each clutch includes:

a ratchet wheel that is fixedly mounted on a respective stub axle,

a primary ring gear that is f reely rotatabiy mounted on the stub axle, and one or more pawls that are each pivotal iy connected to the primary ring gear and have a ramped tooth that is urged into contact with the ratchet wheel,

wherein rotation of the primary ring gear is transferred to the transverse shaft, and wherein rotation of the ratchet wheel in a first direction by forward rotation of the respective drive wheel is transferred to the primary ring gear. In such embodiments, the drive mechanism also includes two secondary ring gears that are each connected to the transver e shaft, and wherein each secondary ring gear is rotatably connected to a respective one of the primary ring gears. Preferably, the teeth of each primary ring gear directly engages with the teeth of the respective secondary ring g ar.

Preferably, each clutch includes a pair of pawls that are pivotal!y connected to the respective primary ring gear. Preferably, the drive mechanism is geared such that the rotational speed of the brushes is greater than the rotational speed of the drive wheels. Preferably, the overall gear ratio of the drive mechanism is in the range of 2:1 to 6:1, More preferably, the overall gear ratio is approximately 4:6:1. In at least some embodiments, the pitch circle diameter of the primary ring gears is larger than that of the secondary ring gears. Alternatively, the primary ring gears and secondary ring gears can have a 1 : 1 ratio.

In some embodiments, the track width of the two drive wheels is approximately the same as the combined width of the brushes. Preferably, the brush shafts are forward of the stub axles of the drive wheels.

The pool cleaner may also have one or more castors to support the chassis. Preferably, the castors support the chassis rearwardly of the drive wheels. The or each castor can swivel relative to the chassis.

The handle is preferably elongate. In certain embodiments, the handle is telescopic. The handle can be connected to the chassis by a pivot that enables the handle to pivot in a transverse direction relative to the forward movement direction of the pool cleaner.

The receptacle includes a mesh bag. The handle can include a hook on which a rear portion of the bag is to hang, The receptacle can also include a duct that directs swept detritus into the mesh bag. The duct preferably has a mouth that is disposed rearwardly behind the brushes. ln some embodiments, the receptacie also includes a backflow preventer to prevent detritus exiting the bag. The backfiow preventer can include a flap. Alternatively or additionally, the receptacle includes a tortuous path in the duct and/or bag that inhibits detritus exiting the bag.

The pool cleaner can also include an outer housing. The outer housing can be shaped such that hydrodynamic loads incurred by forward movement of the pool cleaner urge the chassis into engagement with the supporting surface. in certain embodiments, the outer housing forms the chassis of the poo! cleaner.

Brief description of the drawings

In order that the invention may be more easily understood, embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 : is a perspective view of a pool cleaner according to an embodiment of the present invention;

Figure 2: is an enlarged view of region A of Figure 1 ;

Figure 3: is a perspective view of the pool cleaner of Figure 1 , with the outer housing removed;

Figure 4: is an enlarged view of region B of Figure 3;

Figure 5: is an enlarged view of region C of Figure 4;

Figure 6: is a side view of ihe pooi cleaner as shown in Figure 5;

Figure 7: is a top view of the pooi cleaner as shown in Figure 5;

Figure 8: is a bottom view of the pool cleaner as shown in Fi ure 5;

Figure 9: is a partial perspective view of internal components of a pool cleaner according to a second embodiment of the present invention; and Figure 10: is an elevation view of a clutch of the pool cleane according to the second embodiment.

Detailed description

Figures 1 to 8 show a pool cleaner 10 that includes a chassis, which in this particular embodiment, forms an outer housing 12 of the pooi cleaner 10. The pool cleaner 10 includes a pair of drive wheels 14 that, in use, engage containment surfaces (such as the floor, walls, and stair treads and risers) of a pool and support the outer housing 1 above the containment surfaces.

The pool cleaner 10 has a pair of circular brushes 16, and a drive mechanism that receives rotational motion from the drive wheels 14 and transfers that rotational motion to cause the brushes 16 to counter-rotate. In Figures 2 to 4, 7 and 8, the rotational direction of the brushes 16 is indicated by arrows D, When the brushes 16 rotate in the indicated direction, detritus (such as leaves, twigs and large pieces of dirt) are swept rearwardty through brushes 16. The swept detritus is received in a receptacle, which is described in further detail below.

A handle 18 is provided, the handle 18 being connected to the outer housing 12 such that a user works to advance the poo! cleaner 10 along the containment surfaces. This forward movement of the pool cleaner 10 causes the drive wheels 14 to rotate, which causes the brushes to rotate.

The pool cleaner 10 provides for manually operated cleaning, and can readily and efficiently collect detritus that accumulates on containment surfaces of a pool. As will be appreciated, the pool cleaner 10 provides a cleaning device that can complement the cleaning function of automated cleaners.

As is most evident from Figure 6. the brushes 16 are inclined such that the forward-most portion of the brushes 16 is lower than the rear-most portion. This inclination is indicated in Figure 6 by angle . Thus, when the pool cleaner is resting on its wheels, the forward-most bristles contact the surface that is to be cleaned, and the rear-most bristles are raised above that surface. This has the advantage of releasing detritus that has passed through the nip between the brushes 16 for subsequent collection in the receptacle. The components of the drive mechanism of this particular embodiment are illustrated in Figures 3 to 8. which show the pool cleaner 10 with the outer housing omitted. Each brush 16 has a hub 20 from which bristles 22 extend at least partly radially. The hub 20 of each brush is mounted on a respective brush shaft 24. The drive mechanism includes two right-angle gear sets that are each connected to a respective brush shaft 24. In particular, the right-angle gear sets each include a pair of bevel gears 26a, 26b that are mounted at right angles to one another. Bevel gears 26a are mounted on a respective brush shaft 24, and beve! gears 26b are mounted on a common transverse shaft 28. The bevef gears 26b rotate with the transverse shaft 28, and the teeth of the bevel gears 26a, 26b in each right-angle gear set mesh to transfer the rotational motion through a right-angle to the respective brush shafts 24, As is evident from Figure 3, the right-angle gear sets are arranged such that the brushes 16 counter- rotate with respect to one another. Furthermore, as the brushes 16 are associated with a common transverse shaft 28, both brushes 16 rotate at the same speed, although in opposite directions. Thus, rotational motion from the drive wheels 14 is transferred to the transverse shaft 28, through the right-ang!e gear sets to the brushes 16,

The drive mechanism also includes a clutch associated with each drive wheel 14. The clutch allows the brushes 16 to rotate only with forward rotation the drive wheels 14. Accordingly, rearward rotation of the drive wheels 14 is not transferred to the brushes 16. This ensures that detritus that has been previously swept through the nip between the brushes 1 is not disgorged with rearward movement of the pool cleaner 10. in this embodiment, each drive wheel 14 is mounted on a stub axle 30, which extends through, and is supported by, the outer housing 12. A primary ring gear 32 is freely rotatably mounted on each stub axle 30 inside the housing 12. Each clutch includes a ratchet wheel 34 that is fixedly mounted on a respective stub axle 30, and a pair of pawls 36 that are each pivotaliy eonnected to the respective primary ring gear 32. Each pawl 36 has a ramped tooth that is urged into contact with the ratchet ramps on the respective ratchet wheel 34. To this end, a spring (not shown} provides a biasing force to urge each pawl 36 into contact with the ratchet wheel 34. Rotation of each drive wheel 14 in the forward direction causes the respective pawls 36 to catch against the ramps on the respective ratchet wheel 34, thus transferring rotational motion to the primary ring gear 32. Conversely, rotation of each drive wheel 14 in the reverse (rearward) direction causes the respective pawls 36 to slide over the ramps on the respective ratchet wheel 34, thus enabling the ratchet wheel 34 to rotate without rotating the primary ring gear 32.

In this embodiment, the drive mechanism also includes two secondary ring gears 38 that are each connected to the transverse shaft 28, and each secondary ring 38 gear is rotatably connected to a respective one of the primary ring gears 32. In particular, in this embodiment the teeth of each primary ring gear 32 mesh with the teeth of the respective secondary ring gear 38. The pitch circle diameter of the primary ring gears 32 is larger than that of the secondary ring gears 38. Accordingly, the primary ring gears 32 and secondary ring gears 38 have a ratio that is greater than 1 :1. Consequently, the rotational speed of the transverse shaft 28 is greater than that of the drive wheels 14,

Further, the pitch circle diameter of the bevel gears 26b (which are mounted on the transverse shaft 28) is larger than that of the bevel gears 26a that are mounted on respective brush shafts 24. Accordingly, the right-angle gear sets have a ratio that is greater than 1 :1 , and thus the rotational speed of the brush shafts 24 is greater than that of the transverse shaft 28. Thus, in this particular embodiment, the rotational speeds of the brushes 16 is significantly greater than that of the drive wheels 14.

In this particular embodiment, the drive mechanism is configured to cause rotation of the brushes 16 ' with rotation of either drive wheel 14. Thus, if the pool cleaner 10 is rotated on an axis that is centred on one of the drive wheels 14 (such that one drive wheel rotates, but the other does not), the brushes 16 will rotate being driven by the rotating drive wheel 14. Further, if the pool cleaner 10 is rotated on an axis that is outside the track of the drive wheels 14 (such that one drive wheel rotates faster than the other), the brushes 16 will rotate being driven by the faster rotating drive wheel 14. in this latter movement, the clutch that is associated with the slower rotating drive wheel compensates for the different rotational speeds of respective the primary ring gear 32 and ratchet wheel 34.

As shown most clearly in Figures 7 and 8, the track width of the two drive wheels 14 is approximately the same as the combined diameters of the brushes 16. This enables the pool cleaner 10 to be driven with one of the drive wheels 14 against an upright surface (relative to the brushes 16), whilst still sweeping up detritus.

The pool cleaner 10 also has a pair of castors 40 that support the outer housing 12 rearwardly of the drive wheels 14. The castors 40 assist in raising the back of the outer housing 12, and maintaining the rear-most bristles above the surface to be cleaned, as previously described.

The handle 18 is long and is telescopic (as indicated in Figures 1 and 3 by double- headed arrow T), with a locking mechanism to fix the handle 18 at a desired length. The handie 18 is also connected to the outer housing 12 by a pivot 42 that enables the handle 18 to pivot in a transverse direction (as indicated in Figure 7 by double-headed arrow P).

The receptacle includes a mesh bag 44, and a duct 46 that directs swept detritus into the mesh bag 44. The handle 18 has a hook 48 on which a rear portion of the bag 44 is to hang. The duct 46 has a mouth that is disposed rearwardly behind the brushes 16. Furthermore, the mouth has a lower lip 50 that is to rest on the surface to be swept, as shown in Figures 6 and 8. Figure 9 is a view of internal components of a pool cleaner according to a second embodiment. The pool cleaner of the second embodiment has many features in common with the pool cleaner 10 shown in Figures 1 to 8, aithough many features are omitted for clarity. In Figure 29 the features of the pool cleaner of the second embodiment that are substantially similar to those of the pool cleaner 10 have the same reference numeral with the prefix "1 ".

The pool cleaner of the second embodiment has a chassis, a pair of drive wheels 114, a pair of circular brushes 116, and a drive mechanism, in Figure 9, only one of the drive wheels 1 14 and one of the brushes 116 are illustrated. The drive mechanism receives rotational motion from the drive wheels 1 14 and transfers that rotational motion to cause the brushes 1 16 to counter-rotate, in Figure 9, the rotational direction of the illustrated brush 1 16 is indicated by arrow D.

Each brush 116 has a hub 120 from which bristles 122 extend at least partly radially. The hub 120 of each brush is mounted on a respective brush shaft 124, The drive mechanism includes two right-angle gear sets (only one of which is shown in Figure 9) that are each connected to a respective brush shaft 124. The right-angle gear sets each include a pair of bevel gears 126a, 126b that are mounted at right angles to one another. Bevel gears 126a are mounted on a respective brush shaft 124, and bevel gears 126b are mounted on common transverse shaft 128. The bevel gears 126b rotate with the transverse shaft 128, and the teeth of the bevel gears 126a, 126b in each right-angle gear set mesh to transfer the rotational motion through a right-angle to the respective brush shafts 124, As the right-angie gear sets are mounted on a common transverse shaft 128, both brushes 1 16 rotate at the same speed, although in opposite directions. Th e drive mechanism also includes a clutch associated with each drive wheel 14. The clutch allows the brushes 1 16 to rotate only with forward rotation the drive wheels 1 14. In this embodiment, both drive wheels 1 14 are mounted on a common transverse ax!e 30. Each drive wheel 1 14 has a set of internal gear teeth 152, that are arranged on an internal surface of the wheel rim. A pinion 154 is rotatably mounted on one end of a stub shaft 156, and has gear teeth 158 that mesh with the gear teeth 152 such that the pinion 154 rotates with rotation of the respective drive wheel 1 4.

The pinion 154 and stub shaft 156 incorporate a clutch that is arranged such that the stub shaft 156 is rotated with forward rotation of the respective drive wheel 1 14. but remains stationary with rearward rotation of the respective drive wheel 1 14. The clutch is shown in further detail in Figure 10. in this embodiment, the clutch is provided by a set of ramps 160 formed on an internal surface of the pinion 154, and a shuttle pin 162 that is disposed in a transverse hole {not shown) that extends through the stub shaft 158.

More particularly, the ramps 160 are formed in an internal recess 164 of the pinion 154, and the ramps 160 face towards the stub shaft 156 and are arranged such that none of the ramps 160 are diametrically opposed within the recess 164 to any of the other ramps 160, as is evident from Figure 10. In this embodiment, there are three ramps 160 that are spaced at 120 s intervals around the pinion 154. The shuttle pin 162 is free to move in a radial direction relative to the stub shaft 156. The length of the shuttle pin 182 is slightly less than the distance between the peak of each ramp 180 and a point that is diametrically opposite on the internal recess 164 of the pinion 154.

When the pinion 154 is rotated in the forward direction (indicated by arrow F in Figure 10), the shuttle pin 162 engages with the short side of one of the ramps 160, and this causes the stub shaft 158 to rotate with the pinion 154. Accordingly, rotation of each drive wheel 1 14 in the forward direction causes the respective pinion 154 to rotate in the forward direction F, and this in turn causes the shuttle pin 162 to engage with one of the ramps 160. Thus, each stub shaft 156 is caused to rotate with rotation of the respective drive wheel 1 14 in the forward direction. When the pinion 154 is rotated in the rearward direction (the opposite direction to that indicated by arrow F), the shuttle pin 162 osciflates within the internal recess 164 by sequential contact with the long sides of the ramps 160, Accordingly, rotation of each drive wheel 1 14 in the reverse (rearward) direction causes the respective pinion 154 to rotate in the rearward direction, and this in turn causes the shuttle pin 162 to oscillate within the respective internal recess 184, Thus, each drive wheel 114 is able to rotate in the rearward direction without rotating the stub shaft 156.

The drive mechanism includes a pair of primary ring gears 132 that are each mounted on a respective stub shaft 156 at the opposing end to the pinion 154; the primary ring gears 132 rotate wit the respective stub shaft 156, The drive mechanism also includes two secondary ring gears 138 that are each connected to the transverse shaft 128. Each secondary ring 138 gear is rotatab!y connected to a respective one of the primary ring gears 132. In particular, in this embodiment the teeth of each primary ring gear 132 mesh with the teeth of the respective secondary ring gear 138. The primary and secondary ring gears 32, 38 have the same pitch circle diameter, and thus the primary and secondar ring gears 32, 38 have a 1 :1 gear ratio, and thus the right-angle gear sets has a 1 :1 gear ratio. Consequently, the rotational speed of the transverse shaft 128 is the same as that of the stub shafts 156. As is evident from Figure 9, the gear teeth 158 of the pinion 154 are arranged on a pitch circle that has a smaller diameter than thai of the pitch circle of the internal gear teeth 152 on the drive wheel 114, Accordingly, the pinion 154 rotates faster than the respective drive wheel 1 14. The gear ratio of the gear teeth 158 and the internal gear teeth 152 is, in this embodiment approximately 4.6:1.

As with the drive mechanism of the embodiment illustrated in Figures 1 to 8. the drive mechanism is configured to cause rotation of the brushes 1 16 with rotatio of either drive wheel 1 14. Further, if the pool cleaner 1 10 is moved such that there is a speed differentia! between the drive wheels 114, the brushes 1 16 will rotate being driven by the drive wheel 1 14 that is rotating faster in the forward direction. In this latter movement, the clutch that is associated with the slower rotating drive wheel compensates for the different rotational speeds of respective the primary ring gear 32 and ratchet wheel 34.

As with the pool cleaner 10, the pool cleaner of the second embodiment is to have an outer housing that forms the chassis, and a handle that is pivotally connected to the chassis. Swept detritus is received in a receptacle, as described herein. The brushes 1 16 are to be inclined such that the forward-most portion of the brushes 116 is lower than the rear-most portion when the pool cleaner is on a fiat horizontal surface.

The invention has been described by way of non-limiting example only and many modifications and variations may be made thereto without departing from the spirit and scope of the invention. in some embodiments, the outer housing includes portions that are shaped such that hydrodynamic loads incurred by forward movement of the pool cleaner urge the chassis into engagement with the supporting surface. To this end, the outer housing may include a central portion that is sloped down towards the front of the housing, whereby water flowing over the housing creates downforce, which increases the force on the drive wheels and increases grip.

The outer housing may also include one or more holes to facilitate submersion of the pool cleaner in a body of water. In some embodiments, the receptacle also includes a backflow preventer to prevent detritus exiting the bag. The backflow preventer can include flap disposed in the duct. Alternatively or additionally, the receptacle includes a tortuous path in the duct and/or bag that inhibits detritus unintentionally exiting the bag. The clutch can take alternative forms, such as a freewheel clutch, a Sprag-type clutch, or similar device.

In some embodiments, the primary and secondary ring gears are connected by a chain, belt or the like.

In some alternative embodiments, the drive mechanism includes a flexible shaft that extends between at least one of the stub axle of the drive wheels, and the brush shafts. In such embodiments, the drive mechanism may also include a gearbox, such as a planetary gearbox, to increase the ratio between rotational speed of the brushes.