Wheel arrangement for swimming pool cleaner

A pool cleaner for cleaning a pool includes a housing with an upper surface and downwardly projecting sidewalls extending from the upper surface for defining a front, a rear, a first and a second side of the housing. A first pair of wheels includes a first wheel being pivotally mounted relative to the first side of the housing and a second wheel being pivotally mounted relative to the second side of the housing. A tie rod is operatively mounted relative to the first wheel and the second wheel. A second pair of wheels is mounted on the rear end of the housing. As the pool cleaner traverses a pool surface and the first or second wheel is moved to be at a predetermined angular relationship relative to the housing, the tie rod ensures that the first and second wheels are at substantially the same angular relationship relative to the housing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to the arrangement for the wheels of a pool cleaner wherein when a first or a second wheel is imparted with a predetermined angular relationship relative to a housing for the pool cleaner, a tie rod ensures that the first and second wheels will have substantially the same angular relationship relative to the housing.

2. Description of Background Art

A pool cleaner should be designed to traverse a pool whereby the entire bottom surface of the pool is cleaned. Hithertofor, a laterally offset fixed bumper element was provided on both ends of a pool cleaner to contact a sidewall of the pool and thereafter pivot the pool cleaner to assume a different trajectory when the motor for the pool cleaner is reversed. Thus, as the pool cleaner traverses the bottom of the pool, the bumper element will engage a sidewall of the pool and the angular relationship of the pool cleaner relative to the pool sidewall will be changed so that the pool cleaner will assume a different trajectory as it reverses direction.

In addition, pool cleaners are available that employ three wheels wherein one of the wheels is mounted on an axle that determines the direction of trajectory of the pool cleaner. The third wheel is mounted separately from the pair of wheels that support the pool cleaner for permitting a free-wheeling of the third wheel for enabling the pool cleaner to change directions.

If a pool cleaner is constructed with a single wheel that is pivoted relative to the pool cleaner housing, as the single pivoted wheel engages a wall surface of the pool, the pool cleaner will tend to move at an angle away from the longitudinal axis as it causes extra drag and tends to guide the unit to move at an angle to its longitudinal axis while the other non-pivotal wheels tend to make the unit travel along the longitudinal axis. This causes the unit to be unstable and move in an initial arc and then finally straighten our as long as all four wheels have the same friction between the wheels and the surface of the pool.

If a pool cleaner is constructed with two front wheels that are pivoted relative to the pool cleaner housing, as the left wheel swings to the left the right wheel swings to the right. When this happens, both wheels that are at opposing angles relative to the housing for the pool cleaner will create an equal and opposite drag that will result in a balanced and therefore a stable reversing motion which is undesirable for swimming pool cleaners.

SUMMARY AND OBJECTS OF THE INVENTION

It is one object of the present invention to provide a pool cleaner wherein the front wheels may be turned in tandem to an angular relationship relative to a housing for the pool cleaner by contact with the pool wall or other factors within the pool environment.

Another object of the present invention is to provide a first random timing mechanism that will delay the reversing of a drive mechanism for the pool cleaner as one of the front wheels engages a wall surface of a pool.

A further object of the present invention is to provide a second random timing mechanism wherein the direction of movement of the pool cleaner will be periodically changed throughout a cleaning cycle of the pool.

These and other objects of the present invention are achieved by providing a pool cleaner for cleaning a pool that includes a housing with an upper surface and downwardly projecting sidewalls extending from the upper surface for defining a front end, a rear end, a first side and a second side of the housing. A first pair of wheels is mounted relative to the front end of the housing. The first pair of wheels includes a first wheel being pivotally mounted relative to the first side of the housing and a second wheel being pivotally mounted relative to the second side of the housing. A tie rod is operatively mounted relative to the first wheel and the second wheel for ensuring substantially the same angular relationship of the first wheel and the second wheel relative to the housing. A second pair of wheels are mounted relative to the rear end of the housing. When the pool cleaner traverses a pool surface and the first wheel is moved to be at a predetermined angular relationship relative to the housing, the tie rod imparts movement to the second wheel for ensuring that the first and second wheels are at substantially the same angular relationship relative to the housing. However, the directional wheels are not locked into a fixed longitudinal angle or a fixed lateral position relative to the housing nor do the directional wheels move in a longitudinal axis relative to the cleaner body.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated inFIGS. 1 and 2, a pool cleaner10is provided for cleaning a swimming pool that includes a housing12with an upper surface14and downwardly projecting sidewalls extending downwardly from the upper surface14for defining a front end16, a rear end18, a first side22and a second side24of the housing12.

A first pair of wheels are mounted relative to the front end16of the housing, the first pair of wheels includes a first wheel26being pivotally mounted relative to the first side22of the housing12and a second wheel28that is pivotally mounted relative to the second side24of the housing12. A tie rod32is operatively mounted relative to the first wheel26and the second wheel28for ensuring substantially the same angular relationship of the first wheel26and the second wheel28relative to the housing12. A second pair of wheels34,36are mounted relative to the rear end18of the housing12. The second pair of wheels34,36are connected to a drive mechanism38for providing rotary motion to the wheels34,36for propelling the pool cleaner10relative to a surface of a swimming pool.

As the pool cleaner10traverses a pool surface and the first wheel26engages a wall surface to be moved to be at a predetermined angular relationship relative to the housing12, the tie rod32imparts movement to the second wheel28for ensuring that the first wheel26and the second wheel28are at substantially the same angular relationship relative to the housing. As illustrated inFIG. 1, the first wheel26and the second wheel28are arranged to be substantially in a longitudinal direction relative to the pool cleaner10for enabling the pool cleaner to move in substantially a straight path.

As illustrated inFIG. 2, the first wheel26and the second wheel28are arranged to be at an angular relationship relative to the housing12for enabling the pool cleaner to move in a trajectory that is at an angle relative to the previous trajectory of the pool cleaner10. The pool cleaner10is designed to move completely randomly relative to a surface of a swimming pool to ensure that the entire swimming pool is cleaned.

The first wheel26and the second wheel28projected outwardly relative to the front end16of the housing12for enabling either the first wheel26or the second wheel28to engage a wall surface of a pool for imparting a turning motion to the first wheel26or the second wheel28for changing the angular relationship of the wheels26,28relative to the housing12. The tie rod32is designed to move the first wheel26and the second wheel28in a controlled tandem relationship for maintaining the angular relationship of the wheels26,28relative to the housing12.

A reversible drive mechanism38is provided for imparting rotation to the second pair of wheels34,36for enabling the pool cleaner10to traverse a pool surface and for changing the trajectory of the pool cleaner when the first wheel26and second wheel28are moved to a predetermined angular relationship relative to the housing12.

FIGS. 3-5are enlarged views of the second wheel28and the mounting mechanism40for securing the second wheel28to the second side24of the housing12. The mounting mechanism40includes a support42for securing the mounting mechanism40relative to the housing12. A first arm44extends from the support42. A second arm48is hinged at a proximal end to the first arm44by means of a pin46. The tie rod32is connected to a distal end of the second arm48for ensuring that the first wheel26and the second wheel28are disposed at substantially the same angular relationship relative to the housing12. The second wheel28is mounted relative to the mounting mechanism40at a point adjacent to the member52. A second pivot connection54is provided on the first arm44. If no pin is positioned within the second pivot connection54, a larger angle of swing is permitted for the second wheel28. If a pin is engaged within the second pivot connection54, the second wheel28is limited in the angle of swing. A larger angle of swing is desirable for an unusually shaped pool and/or a pool with obstructions to ensure complete coverage for the pool cleaner10for cleaning the swimming pool. The construction of the mounting mechanism for the first wheel is the same as the mounting mechanism40for the second wheel28. Thus, a description of the mounting mechanism for the first wheel will not be provided.

A motion sensor62is positioned within the second wheel28for detecting if the second wheel28engages a wall surface for actuating a control mechanism64for reversing the drive mechanism38for reversing the direction of the pool cleaner10. The motion sensor62may be a reed switch with a magnet for directly measuring the wheel motion. In addition, a similar motion sensor is positioned within the first wheel26for actuating the control mechanism64for reversing the drive mechanism38for reversing the direction of the pool cleaner10. Other types of motion sensors such as a proximity switch are within the scope of the present invention. A hollow axle is employed to permit a sensor wire to run through the axle without affecting wheel rotation and for providing an accurate and direct wheel rotation measurement.

The control mechanism64includes a first random timing logic for delaying the reversing of the drive mechanism38after either the first wheel26or the second wheel28engages a wall surface of a pool. In addition, the control mechanism64includes a second random timing logic for periodic reversing of the drive mechanism randomly throughout a cleaning cycle of a pool.

FIGS. 6 and 7illustrate schematic views of the pool cleaner10wherein the first wheel26and the second wheel28are tied together by the tie rod32to ensure that the first wheel26and the second wheel28are moved in the same direction. As illustrated inFIG. 6, if the second wheel28hits a wall of the swimming pool, the pool cleaner10tends to move to the right. Similarly, as illustrated inFIG. 7, if the first wheel26hits the wall of the swimming pool, the pool cleaner10tends to move to the left. The tie rod32ensures that both the first wheel26and the second wheel28are moved in the same direction to be at substantially the same lateral angular relationship relative to the housing12.

By incorporating the first random timing logic for controlling the time delay between the pool cleaner10hitting a wall surface before the pool cleaner10reverses, the reverse path is more unpredictable. If the delay timing is long enough to allow the unit to keep pushing against the wall to the extent that the whole unit pivots about the point of the wheel and the wall contact, the whole unit rotates about the point of contact. When the pool cleaner10reverses, the pool cleaner10will be at a random trajectory as compared to the previous trajectory. A longer push to rotate before the reversal of the drive mechanism results in a more dramatic turn between the forward path and the reverse path. A shorter push to rotate before the reversal of the drive mechanism results in a less dramatic turn between the forward path and the reverse path.

The second random timing logic is provided in the control mechanism64for periodically reversing the direction of the cleaner while it is traversing a surface of the pool. The combination of the first random timing logic and the second random timing logic patterns assures unpredictability in the movement of the pool cleaner10for providing the best coverage of the pool surface.