Automatic pool cleaner gear change mechanism

A mechanism (106) for selecting one of a first gear (102) and a second gear (104) for driving an automatic swimming pool cleaner (10) includes a bi-stable oscillating gear change assembly (100). The assembly is moveable between a first position wherein the first gear is engaged and a second position wherein the second gear is engaged. A first magnet (142) is carried by the assembly. A second magnet (138, 140) is carried externally of the assembly on the cleaner body (18). A cam arrangement (152, 160) initiates movement of the assembly (100) from one of the first and second positions to enable mutually repelling forces between like poles of the first and second magnets (142, 138, 140) to cause the assembly to settle in another of the first position and the second positions, thereby to change between the first and second gears quickly and cleanly.

TECHNICAL FIELD

THIS invention relates to automatic cleaners for surfaces submerged in a liquid and more particularly to such cleaners which are operated by a liquid driven turbine.

Known suction and pressure operated turbine driven cleaners for a floor and walls of a swimming pool suffer from the disadvantage that when they move through a sharp corner region between the floor and a wall, traction and suction are lost which impede their ability to scale the wall. Furthermore, operation of gear change mechanisms on the known machines for causing the cleaner to change from movement in a first direction to movement in an opposite direction is, due to the complex nature of these mechanisms, not reliable enough, which results in damage to gears and even jamming and malfunctioning of the mechanisms.

OBJECT OF THE INVENTION

Accordingly it is an object of the present invention to provide an alternative cleaner and alternative mechanism for changing gears with which the applicant believes the aforementioned disadvantages may at least be alleviated.

DISCLOSURE OF THE INVENTION

According to the invention there is provided a mechanism for changing between a first gear and a second gear on an automatic swimming pool cleaner, the mechanism comprising:an oscillatable gear carrying assembly moveable between a first position wherein the first gear is engaged and a second position wherein the second gear is engaged;a biasing mechanism for urging the assembly towards a first position when selected and to the second position when selected; andan actuating arrangement for selecting one of said positions by initiating movement of the assembly from another of said positions, to enable the biasing mechanism to urge the assembly towards the selected one of said positions.

In some embodiments the biasing mechanism may comprise a first magnet having a pole of a first kind and a pole of a second kind which is carried by the assembly and a second magnet having a pole of the first kind and a pole of the second kind mounted externally of the assembly, with the pole of the first kind of the first magnet facing towards the pole of the first kind of the second magnet, so that mutually repelling forces between said first poles urge the assembly towards the selected one of said positions. In other embodiments the biasing mechanism may comprise springs, for example.

The first gear and the second gear may be mounted on the assembly and when the first gear is engaged, the cleaner is driven to move in a first direction and when the second gear is engaged, the cleaner is driven in another direction.

The first gear and the second gear when engaged, may drive a driven gear connected to drive an axle of a wheeled undercarriage of the cleaner.

In one embodiment the oscillatable gear carrying assembly may comprise a turbine driven shaft of the cleaner.

The shaft may comprise a formation engaging a corresponding formation on the turbine for rotatably driving the shaft and the shaft is preferably free for axial movement relative to the turbine between a first position wherein the first gear is engaged and a second position wherein the second gear is engaged.

The assembly may comprise a pivotable member pivoted to a body of the cleaner and for manipulating the shaft between the first position and the second position.

The pivotable member may be connected to cooperate with a bush which is fast with the shaft.

The bush may be mounted in a bearing for rotation with a first part of the bearing, and a second part of the bearing may be mounted on a bearing holder which may be pivotably carried by the member.

The member is preferably an elongate member and the bearing holder is preferably mounted for axial movement relative to the member.

The first magnet may be carried in a foot part of the pivotable member, the second magnet may be mounted on the body of the cleaner and a third magnet may be mounted on the body spaced from the second magnet to define a passage way for the foot part of the pivotable member.

The actuating arrangement for initiating movement may comprise a first cam cooperating with the pivotable member.

The first cam may be a turbine driven cam comprising first and second lobes and the arrangement may further comprise a passive cam comprising first and second lobes.

The first lobe of the first cam may be arranged to engage the member to move the member from the second position and the second lobe may be arranged to cooperate with the first lobe of the second cam to cause the second lobe of the second cam to move the pivotable member from the first position.

The first cam may be driven by the aforementioned turbine, alternatively by a further turbine on the cleaner.

The first gear, the second gear and the driven gear may be bevel gears.

In another embodiment the gear carrying assembly may be pivotably mounted on the body of the cleaner and the first gear may be linked to drive an axle of the wheeled undercarriage of the cleaner.

The first gear may be linked to the axle via a belt and pulley arrangement.

The gear carrying assembly may be actuated and biased to bring a selected one of the first gear and the second gear into meshing relationship with a drive gear fast with a turbine driven shaft of the cleaner.

The first gear and second gear may be mounted in meshing relationship with one another, so that when the drive gear engages the fist gear the cleaner is driven in the first direction and when the second gear is engaged, the second gear causes the first gear to drive the cleaner in the other direction.

The invention also includes within its scope a suction or pressure operated cleaner comprising a mechanism for changing between a first gear and a second gear as herein defined and/or described.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

An automatic swimming pool cleaner according to the invention is generally designated by the reference numeral10in the diagrams. The cleaner is a turbine driven suction cleaner which in use, is connectable in known manner via a water intake (not shown) in a pool12(shown inFIGS. 14 to 16) to an inlet of an electrical circulation pump (not shown) of a circulation and filtration plant (also not shown) for the swimming pool12.

The cleaner in use moves over a floor14and walls16of the pool and under the influence of the suction generated by the pump, sucks up water entraining debris and the like which is then filtered by the filtration plant, before the water is returned into the pool via suitably positioned outlets (not shown) into the pool.

The cleaner10comprises a body18defining a liquid flow passage20(shown inFIG. 4) therethrough. The flow passage20extends between an inlet22into the body18defined in a bottom plate24of the body and an outlet26from the body. A rotatable turbine28for driving the cleaner is mounted in a chamber30in the body to extend into the passage20, to be driven by water moving under the influence of suction from the pool towards the pump. The turbine comprises three equi-spaced curved vanes28.1to28.3. When driven, the turbine rotates in one direction namely a clockwise direction only, as shown inFIG. 4.

As shown inFIGS. 4 and 17, chamber30comprises a lid32which is mounted on body18at hinges34, to pivot between a closed operative position shown inFIG. 4and an open position shown inFIG. 17. When in the open position, debris or the like may be removed from chamber30. On the lid32there are provided dual in line ball joints36and38to enable spigot40defining outlet26to pivot relative to the body.

In use, the spigot40is removably receivable in a socket defined in a conventional flexible hose (not shown) which in use is used to connect the cleaner10to the aforementioned intake in the pool12, as hereinbefore described.

The cleaner10comprises a wheeled undercarriage42for the body18, best shown inFIG. 4. The undercarriage42comprises first, second and third parallel wheeled axles44,46and48. The first axle44is journaled to the body18as shown inFIGS. 1 and 2. The first axle44and second axle46provide a first section50(shown inFIG. 14) of the undercarriage. The second axle46and third axle48provide a second or front section52of the undercarriage and are mounted on an assembly54which is pivotable relative to a front end of the body, as shown inFIGS. 11 to 16. As shown inFIGS. 14 and 15with the first section50negotiating a surface14, the second section52is pivotable in elevation (a) relative to the first section. The advantages and use of the pivotable section52will be described hereinafter.

As shown inFIGS. 1,2,4and11to16, the pivotable assembly54comprises opposed arms80and82which are pivoted at84and86to respective forwardly directed extension formations88and90from body18. Axles46and48are journaled between the arms80and82. A brake81comprising an elongate member83is pivotably mounted at85on arm80. A guide87fast with formation88extends through an elongate slot89defined in the member83. At its distal end, the brake comprises a formation91for engaging a surface of the pool as will hereinafter be described.

As shown inFIGS. 4 and 5, on axle44there are provided a first toothed wheel60and an opposed second toothed wheel62. A first roller64is mounted to extend coaxially between the wheels. On the second axle46there are provided a first toothed wheel66and a second spaced wheel68. A second roller70is mounted to extend coaxially between the first wheel66and second wheel68. On the third axle48there are provided a first wheel72and spaced second toothed wheel74. A third roller76extends between the first wheel72and second wheel74.

As shown inFIGS. 2 and 3, a first endless track92extends about the first wheels60,66and72on the axles44,46and48and a transversely spaced second endless track94extends about the second wheels62,68and74on the aforementioned axles. On inside surfaces of the tracks, there are provided formations96for cooperating with teeth98on the toothed wheels.

As best shown inFIGS. 2,4,5,6and7turbine28drives a hexagonal shaft100of stainless steel. A first bevel gear102is fast at an end of shaft100with its bevel facing the shaft. A second bevel gear104is also fast with the shaft, but spaced from the first gear and with its bevel facing towards the first gear. The shaft100is programmably moveable in an axial direction by a toggle mechanism106(shown inFIG. 2) relative to the turbine28between a first or normal position (shown inFIG. 3) wherein the first gear102engages a beveled driven gear108and a second position (shown inFIGS. 1 and 2) wherein the second bevel gear104engages the driven gear108.

Gear108is fast with rotary drive shaft110journaled by bearings109on the body18and having a further bevel gear112fast at an opposite end thereof. The further bevel gear112meshes with a cooperating bevel gear114which is fast with hexagonal first axle44.

As shown inFIG. 6, first wheel60which is fast with axle44comprises a plurality of radially extending spokes116. The spokes116engage with cooperating slots118defined in cheek or end plate120which is fast with first roller64. The second wheel62on the first axle44is similarly fast with axle44and a second cheek or end plate on the first roller adjacent the second wheel. The roller70is similarly fast with its adjacent wheels and axle. Roller76is similarly fast with the axle48and second wheel74. The rollers are hollow and may house floats to provide suitable buoyancy in different parts of the cleaner.

Referring now toFIGS. 1,2,7to10, the toggle mechanism106comprises a generally inverted y-shaped member120pivoted to the body18at122. The turbine driven shaft100is fast with a bush124defining a socket126through which the shaft100extends. As best shown inFIG. 7, the bush124is mounted in a bearing125allowing rotation of the bush and shaft100. The bearing125in turn is mounted in a bearing holder127which is pivotable between legs131and132of member120and also slidable in a direction X as shown inFIG. 2by opposed stubs135on the holder which extend into opposed slots133defined in the legs131and132.

As shown inFIG. 7, a foot part130of one leg132of the member120extends to a region between two spaced housings134and136on the body18. In the housings134and136there are mounted magnets138and140respectively. A first pole of magnet138faces the foot and an opposite pole of magnet140also faces the foot. In the foot130there is also mounted a magnet142with its first pole facing a similar or like pole of magnet138and its opposite pole facing a similar pole of magnet140.

The pivotal member120comprises an integral stub144defining a slot146between the stub144and an upper region of leg132. A first lobe150of a passive cam152pivotably mounted on the body18at154extends into the slot146. A second lobe156of the cam152cooperates with a driven cam160. The driven cam160is mounted on the body18for rotation in an anti-clock wise direction A (shown inFIG. 7) about an axis162. The cam may be driven by the turbine28alternatively and in a preferred embodiment the cam160is driven by a further turbine and reduction gear train housed in a box164shown inFIGS. 1 and 17. The further turbine is driven by water flowing through inlet165into the box and into the passage way20to the suction pump. The gear train linked with the further turbine drives square shaft166on which the cam160is mounted. As shown inFIG. 8, the cam160comprises a first short lobe168cooperating with lobe156of passive cam152and a second longer lobe170cooperating with stub144in use.

It will be appreciated that with the like poles of magnets138,140and142repelling one another, the pivotable member120has two stable positions. The first is an extended position shown inFIGS. 9 and 3wherein bevel gear102meshes with driven gear108. With this arrangement the turbine drives the cleaner in a forward direction B, shown inFIG. 4. The second is a retracted position shown inFIGS. 1,2,7,8and10wherein the second bevel gear104meshes with driven gear108. With this arrangement the turbine drives the axle44and cleaner in an opposite or reverse direction C, shown inFIG. 4.

Referring toFIG. 9, with the first bevel gear102engaging drive gear108and the pivotal member120in the extended position, shorter lobe168of cam160rotating in an anti-clockwise direction D engages second lobe156of passive cam152. The passive cam is urged in a clockwise direction E as shown inFIG. 9. The longer lobe150of the passive cam engages stub144and urges the pivotal member120to pivot in an anti-clockwise direction. The lobe168engages the lobe156until after a critical point when the repelling forces of the magnets cause foot130and the member120to accelerate towards the second position shown inFIG. 10wherein the shaft is moved axially so that the second bevel gear104engages the driven gear108quickly and cleanly. As stated hereinbefore, the turbine28now drives the axle44in the reverse direction.

As shown inFIG. 10, the rotating cam160continues until the longer lobe170engages stub144. This lobe urges the stub144and the member120to pivot in a clockwise direction F until beyond a critical point wherein the repelling forces of the magnets again cause the member to move quickly into the first or extended position shown inFIG. 9and wherein first bevel gear102again quickly and cleanly engages the driven gear108.

The time periods during which the cleaner will move in the forward direction B and in the reverse direction C are programmable by suitable adjustment of the relative configuration of the lobes168and170of the rotating cam160. It is believed that the sharp action caused by the repelling forces of the magnets will cause the relevant gear102and104smoothly and cleanly to engage the driven gear108.

In other embodiments, the magnets may be replaced by suitable alternative biasing mechanisms or arrangements, such as arrangements comprising springs.

As best shown inFIGS. 1 and 11to13there is provided a ratchet wheel180on the third axle48between the first wheel72and third roller76. A pawl182cooperating with the ratchet wheel is pivotably anchored at184on body18. While the axle44moves in the clock-wise direction as shown inFIG. 11, the pawl simply slips over teeth on the ratchet wheel. However, when the axle44starts to move in the reverse direction to cause the cleaner to move in direction C, the pawl182engages the wheel180, thereby to stop rotation of the third axle48.

The opposed tracks92and94driven by the rear axle44now cause the second section52of the undercarriage to pivot in an anti-clockwise direction G as shown inFIGS. 12though13. At the same time brake81is pivoted in the same direction and formation91engages the surface14as shown inFIG. 13. This causes the one side of the cleaner to move faster around brake81and the cleaner to change direction. Pawl182is released when it engages the formation200on the body18, so that the cleaner is free to move in a reverse direction. The pivoting of section52during reversal of the machine automatically changes a relatively short wheelbase186(shown inFIG. 11) of first section50of the undercarriage during normal forward movement into a relatively longer wheelbase188(shown inFIG. 13), which improves the cleaner's stability when in reverse.

When the cleaner resumes normal forward motion as hereinbefore described, that is when bevel gear102engages driven gear108, the pivotal section52of the undercarriage automatically pivots towards the normal position as shown inFIG. 14with the shorter wheelbase and wherein the brake81is lifted.

In other embodiments, a similar brake (not shown) may be provided in any other suitable position on the machine (for example adjacent each of wheels60and62at the rear of the machine) and which may intermittently be operated by the turbine28or the further turbine via cams or the like, to engage the surface14, thereby to cause the machine intermittently to change direction. In a case where two brakes are provided as aforesaid, they may be operated alternatively.

InFIGS. 14through to16there is illustrated the cleaner10negotiating a corner region in the pool12. InFIG. 14, the pivotable section52is in a normal position. As shown inFIG. 15, when the forwardly moving cleaner10engages the sidewall16, the pivotable section52pivots in an anti-clockwise direction G better to conform to the profile of the corner region. Substantial parts of tracks92and94engage both the floor14and wall16to maintain traction. As shown inFIG. 16, as the cleaner moves closer to and up the wall, the pivotable section progressively pivots in direction H towards the normal position, thereby to maintain sufficient traction and/or suction while the cleaner moves through the corner region. Once on the wall16, the cleaner continues its movement along the wall in the normal configuration as shown inFIG. 14, although there it is shown in normal configuration on the floor.

An alternative embodiment of the drive mechanism and gear change mechanism is shown inFIGS. 18 to 21. In this embodiment the shaft100is square in transverse cross-section and is stationary in an axial direction. A worm gear202is fast with shaft100. A gear204cooperates with the worm gear202to drive a cam206(shown inFIGS. 20 and 21) similar to cam160. Hence, the further turbine and gear train in box164are dispensed with. Shaft100is further fast with a drive gear207. The first axle44is driven by a belt and pulley arrangement comprising a pulley208fast with axle44, a belt210and a pulley212. Pulley212is fast with a gear214of a pivotable assembly215also comprising a gear216on an extension arm218.

The assembly215is pivotable between a first normal position shown inFIG. 18and a second position shown inFIG. 19. In the first position, the drive gear207drives gear216which in turn drives gear214. Gear214drives the belt and pulley arrangement, so that the cleaner moves in a forward direction. In the second position shown inFIG. 19, the drive gear207drives gear214directly, so that the direction of rotation of axle44is reversed.

The assembly215is pivoted by the cam206which is similar to cam160hereinbefore described and cam218which is similar to cam152hereinbefore described. As shown inFIG. 20, lobe220of cam206urges the assembly in a clock-wise direction to bring gear214into direct meshing relationship with drive gear207thereby to reverse the direction of rotation of axle44. As shown inFIG. 21, lobe222of cam206thereafter cooperates with lobe224of cam218to cause lobe226of cam218to pivot the assembly back towards its normal position wherein drive gear207meshes with intermediate gear216which in turn drives gear214as hereinbefore described. The assembly215is caused to move quickly to the first and second positions by a suitable toggle mechanism comprising magnets, similar to the mechanism hereinbefore described or other suitable biasing mechanisms.