Automatic pool cleaner gear mechanism

1. In an automatic pool cleaner comprising a first gear and a second gear, a mechanism for changing between the first gear and the second gear, the mechanism comprising:

a first oscillatable gear carrying assembly moveable between a first position wherein the first gear is engaged to a worm and a second position wherein the second gear is engaged to the same worm;

an actuating arrangement for selecting one of the first and second positions by initiating movement of the oscillatable gear carrying assembly to urge the oscillatable gear carrying assembly towards a selected one of the first and second positions; the first gear and the second gear being mounted on the first oscillitable gear carrying 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 a second direction; and

wherein the first gear and second gear within the first oscillatable gear carrying assembly are always engaged to one another by means of a third gear, the third gear being mounted in a fixed axially oriented position to form a pivot point for the first oscillatable gear carrying assembly when rotated to the first or second positions to engage either the first or second gears with the worm, the relationship of rotation between the worm and first and second gears to be determined so that when under operation torque or friction applied to the third gear either the first or second gear will be biased to a fully engaged position directly with the worm after initial direct contact is made with the worm;

wherein a second oscillatable gear carrying assembly is located in the same axial position as the first oscillatable gear carrying assembly so that one side of the cleaner may reverse in relation to an opposite side of the cleaner when the first oscillatable gear carrying assembly is actuated towards a different position of rotation than the second oscillatable gear carrying assembly.

2. The mechanism as claimed in claim 1 , wherein the worm has a left hand directional thread and a right hand directional thread, such that, when the first gear engages the left hand directional thread on the worm, the cleaner is driven to move in a first direction, and, when the first gear disengages the left hand directional thread and the second gear engages the right hand directional thread the cleaner is driven to move in a second direction.

3. The mechanism as claimed in claim 1 wherein both the first and second oscillatable gear carrying assemblies are actuated to any of said first and second positions by a single cam device to form a fixed timed relationship between the first and second oscillatable gear carrying assemblies in a manner where the cleaner will always follow a predetermined path.

4. The mechanism as claimed in claim 3 wherein the cam will incorporate a predetermined pattern with at least one reverse direction and at least one steering direction, wherein a steering action will immediately be followed by a reversing of direction of the cleaner.

5. The mechanism as claimed in claim 1 wherein the first oscillatable gear carrying assembly will provide input to the one side of the cleaner and the second oscillatable gear carrying assembly will provide input to the opposite side of the cleaner, wherein a fourth gear in either of the first or second oscillatable gear carrying assemblies will be meshed with a fifth gear, wherein the fifth gear is mounted circumferentially to a first set of drive wheels, rollers or pulleys at both the one and opposite sides of the cleaner, wherein the pulleys have at least one tooth, wherein a track with at least one inside formation will provide drive to a second set of drive wheels, rollers or pulleys positioned opposed the first set of rollers, wheels or drive pulleys.

6. The mechanism as claimed in claim 5 , where the fifth gear mounted circumferentially to the first set of drive wheels, rollers or pulleys is molded from a flexible material.

7. A device for cleaning a submerged surface in a fluid comprising a drive mechanism, wherein the drive mechanism is connected to a fluid inlet and outlet, wherein movement of fluid through the fluid inlet to the fluid outlet will allow the drive mechanism to provide rotational input to a worm, wherein an oscillatable gear carrying assembly will include a first and a second gear, wherein the first and second gear will be permanently meshed with a third gear where the third gear is mounted on a fixed axial position in relationship to a cleaner body, wherein the first and second gear together with the oscillatable gear carrying assembly will rotate around the fixed axial position of the third gear, wherein a means to pivot the oscillatable gear carrying assembly around the axially fixed positon of the third gear axis will allow the first and second gear to alternatively directly engage and disengage with the worm, wherein the third gear forms a fixed axially orientated position for output drive to a remainder of a drivetrain, wherein the device will move in one direction when the first gear is engaged to the worm while the second gear is disengaged and an opposed direction when the second gear is engaged to the worm while the first gear is disengaged from the worm; wherein the orientation of rotation of the gears is such that when friction or load applied to the third gear carrying assembly will, upon initial contact with the worm, bias a corresponding one of the first or second gears to pivot towards a fully engaged position with the worm; and wherein the worm will have a left hand type thread and a right hand type thread, such that the first gear will engage to left hand type thread to rotate in an opposed direction to the second gear when the second gear engages to the right hand type thread.

8. The mechanism as claimed in claim 1 wherein a cleaning path will simulate parallel cleaning paths whereby a short turn will precede a reverse of direction change; and

wherein at least one of the turns will be of longer duration to allow a turn of larger degree of no more than 360 degree to precede a direction change to allow the cleaner to proceed to a different area within the pool.

9. In an automatic pool cleaner comprising a first gear and a second gear, a mechanism for changing between the first gear and the second gear, the mechanism comprising:

an oscillatable gear carrying assembly moveable between a first position wherein the first gear is directly engaged to a worm and a second position wherein the second gear is directly engaged to the same worm;

an actuating arrangement for selecting one of the positions by initiating movement of the oscillatable gear carrying assembly to urge the oscillatable gear carrying assembly towards the selected one of the positions; the first gear and the second gear being mounted on the oscillatable gear carrying 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 a second direction; and

wherein the worm has a left hand directional thread and a right hand directional thread such that, when the first gear engages the left hand directional thread on the worm, the cleaner is driven to move in a first direction, and, when the first gear disengages the left hand direction thread and the second gear engages the right hand directional thread, the cleaner is driven to move in a second direction.