AUTOMATIC SWIMMING POOL CLEANERS

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority to U.S. Provisional Patent

Application Serial No. 62/875,599, filed July 18, 2019, the entire contents of which are hereby incorporated herein by this reference.

FIELD OF THE INVENTION

This invention relates to systems and methods for controlling cleaning devices and more particularly, although not necessarily exclusively, to automatic swimming pool cleaners (APCs) configured to counter drifting movement on, for example, generally vertically-oriented walls of swimming pools or spas.

BACKGROUND OF THE INVENTION

APCs are well known. These cleaners often are characterized as either

“hydraulic” or“robotic” (or“electric”), depending on the source of their motive power.

Hydraulic cleaners, for example, typically use pressurized (or depressurized) water to effect their movement within pools, whereas robotic cleaners typically utilize an electric motor to cause their movement. Moreover, hydraulic cleaners frequently are subcategorized as either

“pressure-side” or“suction-side” devices, with pressure-side cleaners receiving pressurized water output from an associated water-circulation pump and suction-side cleaners, by contrast, being connected to an inlet of the pump. Electric motors of robotic cleaners may drive wheels, tracks, or any other suitable mechanisms. If tracks are employed, one track normally is used on each of the left and right sides of a robotic APC. If wheels are utilized, conventionally two (front and rear) are used on each of the left and right sides of the robotic APC, with either the two front or the two rear wheels (or all four wheels) being driven. Shafts, gears, and other standard components may connect the wheels or tracks to the drive motor(s).

Typically, motive means such as tracks or wheels on the left and right sides of a robotic APC are driven at the same speed. Doing so allows the cleaner to travel generally in a forward or rearward direction. Various techniques may be used to cause the robotic

APC to reorient its body within a swimming pool and thus change the direction of movement.

APCs engaged in climbing vertical pool walls may encounter difficulties operating against gravity. One such difficulty is generating sufficient power to drive the tracks or wheels upward while maintaining contact with a vertical wall. Another difficulty may be creating sufficient traction to overcome any transient currents in the pool or starting conditions of climbing that might tend to cause an APC to drift laterally.

DESCRIPTION OF THE INVENTION

The present invention seeks to provide systems and methods of counteracting lateral such drift. Especially useful when an APC is climbing (up) a generally vertically- oriented wall, the invention also may be employed with the APC is travelling along a generally horizontally-oriented pool bottom, climbing down a wall, or otherwise moving within a pool. In particular, the present invention may allow a drifting cleaner to recover its upward movement along a wall by altering traction speed of the track or wheels on one side of the body of the APC.

This concept is illustrated schematically in the FIGURE. Shown therein is generally vertical wall 10 of a swimming pool together with APC 14. Also depicted in the

FIGURE in dotted lines is vertical line 18.

If appropriate, APC 14 may be controllable electronically and include at least one orientation sensor such as (but not necessarily) an accelerometer, a gyroscope, or otherwise. At times, APC 14 may be commanded or configured to climb from a floor or bottom of the pool to its waterline 22 in order to clean wall 10, especially in the region adjacent waterline 22. Such instruction to APC 14 may be to climb vertically along vertical line 18, for example.

Further illustrated in the FIGURE in dotted lines are (nominally) left line 26 and (nominally) right line 30, each forming an angle with vertical line 18. These lines 26 and 30 may exemplify angular drift limits permissible while APC 14 climbs wall 10. Angles formed with respect to vertical line 18 by lines 26 and 30 need not be limited to any particular values, but normally will be greater than 0° and less than ±90°.

Under the example conditions depicted in the FIGURE, APC 14 is climbing vertical wall 10 initially along path P1. This path P1 is angled relative to vertical line 18, illustrating that APC 14 is drifting from the vertical line 18. As the orientation sensor detects that path P1 has equaled or exceeded the drift limit established by the angle between lines 18 and 30, a controller of the APC 14 may signal its drive mechanism to change the traction speed of the motive elements on either the left or the right side of the body of the cleaner 14 so that the speeds are unbalanced. For example, consistent with the FIGURE, speed of the (nominally) right motive means 34 of the APC 14 may be increased so as to turn the body of

APC 14 leftward to follow a path P2 closer to vertical line 18. Alternatively, speed of the

(nominally) left motive means 38 may be decreased to cause APC 14 to follow path P2.

When the orientation sensor senses that APC 14 has returned to a more vertical path, the controller may instruct the drive mechanism to balance the traction speeds of motive means

34 and 38 and allow APC 14 to follow path P3.

Persons skilled in the art will recognize that the unbalanced traction speeds discussed herein may be achieved in any suitable manner. In some versions of APC 14, more than one drive motor may be employed, with the motors operating at different speeds to drive wheels or tracks at different velocities. In other versions of APC 14, a single motor may be geared differently as connected to different tracks or wheels so as to produce different traction speeds. Other techniques recognizable by skilled persons alternatively or additionally may be utilized.

Although the FIGURE schematically illustrates APC 14 climbing up wall 10, systems and methods of the invention could be used when APC 14 is climbing down wall 10 or moving in some other manner with the swimming pool. In such cases other or additional orientation sensors may be needed. Nonetheless, upon detection of a drift or other change of intended course, a sensor and controller of APC 14 may unbalance the left and right traction speeds of the motive means of the cleaner to implement a course correction.

Exemplary concepts and combinations of features of the invention may include: A. A method of causing an automatic swimming pool cleaner having a body to counteract a deviation from an intended course.

B. A method according to statement A. in which counteraction of the deviation from the intended course occurs by driving a first motive element on a first side of the body at a different speed than a second motive element on a second side of the body opposite the first side.

C. An automatic swimming pool cleaner comprising a body, an orientation sensor, a controller, at least one drive mechanism, a first motive element on a first side of the body, and a second motive element on a second side of the body opposite the first side; and in which the at least one drive mechanism is configured to drive the first motive element at a different speed than the second motive element upon command of the controller when the orientation sensor senses that the body is oriented in a manner other than planned.

These examples are not intended to be mutually exclusive, exhaustive, or restrictive in any way, and the invention is not limited to these example embodiments but rather encompasses all possible modifications and variations within the scope of any claims ultimately drafted and issued in connection with the invention (and their equivalents). For avoidance of doubt, any combination of features not physically impossible or expressly identified as non- combinable herein may be within the scope of the invention. The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention. Additionally, the word“pool” and phrase

“swimming pool” as used herein may include vessels such as spas and hot tubs within their definitions.