Electric powered automatic swimming pool cleaning system

[0002] This application is a continuation-in-part of U.S. application Ser. No. 08/998,170, filed Dec. 25, 1997, now U.S. Pat. No. 5,985,156, and also relates to U.S. application Ser. No. 08/998,528 now U.S. Pat. No. 6,090,219, entitled POSITIVE PRESSURE AUTOMATIC SWIMMING POOL CLEANING SYSTEM and U.S. application 08/998,529, now U.S. Pat. No. 6,039,886 entitled WATER SUCTION POWERED AUTOMATIC SWIMMING POOL CLEANING SYSTEM, all of whose disclosures are incorporated herein by reference.

[0003] The present invention relates to a method and apparatus for automatically cleaning a swimming pool.

[0004] The prior art is replete with different types of automatic swimming pool cleaners. They include water surface cleaning devices which typically float at the water surface and can be moved across the water surface for cleaning, as by skimming. The prior art also shows pool wall surface cleaning devices which can rest at the pool bottom and can be moved along the wall (which term should be understood to include bottom and side portions) for wall cleaning, as by vacuuming and/or sweeping. Some prior art assemblies include both water surface cleaning and wall surface cleaning components tethered together.

[0005] The present invention is directed to a method and apparatus useful for automatically cleaning a water pool contained in an open vessel defined by a wall having bottom and side portions.

[0006] Applicant's parent application describes apparatus including a unitary body having (1) a level control subsystem for selectively moving the body to a position either proximate to the surface of the water pool or proximate to the interior surface of the containment wall, (2) a propulsion subsystem operable to selectively propel the body in either a forward or rearward direction, and (3) a cleaning subsystem operable in either a water surface cleaning mode (e.g., skimming or scooping) or a wall surface cleaning mode (e.g., vacuuming or sweeping). The parent application discloses that these subsystems can be powered by hydraulic, pneumatic, and electric power sources and specifically describes hydraulic embodiments powered by positive and negative water pressure. The present invention is directed to electric powered embodiments.

[0007] More specifically, in accordance with the present invention, one or more of the aforementioned subsystems is powered by an electric source such as solar cells and/or rechargeable batteries and/or a wire extending to the unitary body from an external (e.g., deck mounted) power source. The batteries can be charged from solar cells carried by the unitary body or via electric terminals in an appropriately configured docking station.

[0008] Preferred embodiments of the invention are configured with one or more electric motors which are selectively controlled to generate pool water flows for level control, propulsion, and/or cleaning.

[0009] Embodiments of the invention can use either a heavier-than-water body or a lighter-than-water body. When a heavier-than-water body is used, the body in its quiescent or rest state typically sinks to a position proximate to the bottom portion of the containment wall. In an active state, the level control subsystem produces a vertical force component for lifting the body to proximate to the water surface.

[0010] When a lighter-than-water body is used, the body in its quiescent state floats at a position proximate to the water surface. In an active state, the level control subsystem produces a vertical force component for causing the body to descend to proximate the wall bottom portion.

[0011] Embodiments of the invention are preferably configured to return the body to its quiescent state in the event electric power terminates; e.g., battery depletion.

[0012] FIGS. 1A and 1B respectively schematically depict heavier-than-water and lighter-than-water embodiments of the invention powered by a flexible electric wire;

[0013] FIG. 1C and 1D respectively schematically depict heavier-than-water and lighter-than-water embodiments powered by fully on-board electric power sources, e.g., solar cells and/or rechargeable batteries;

[0014] FIG. 2 is a functional block diagram generally representing the level control, cleaning control, and propulsion control subsystems utilized in preferred embodiments of the invention;

[0015] FIG. 3 is a more detailed block diagram of a preferred embodiment of the invention;

[0016] FIG. 4 comprises a side view of a first structural embodiment of the invention cutaway to the right of line C to show internal body detail;

[0017] FIG. 5 comprises a top view of the body of FIG. 4; and

[0018] FIG. 6 comprises a sectional view taken substantially along the plane 6—6 of FIG. 4;

[0019] With initial reference to FIGS. 1A and 1B, the present invention is directed to a method and apparatus for cleaning a water pool 1 contained in an open vessel 2 defined by a containment wall 3 having bottom 4 and side 5 portions. Embodiments of the invention utilize a unitary structure or body 6 capable of being immersed in the water pool 1, for selective operation proximate to the water surface 7 or proximate to the interior wall surface 8.

[0020] The unitary body 6 preferably has an exterior surface contoured for efficient travel through the water. Although bodies 6 in accordance with the invention can be very differently shaped, it is intended that they be relatively compact in size fitting within a two foot cube envelope. FIG. 1A depicts a heavier-than-water body 6 which in its quiescent or rest state typically sinks to a position (shown in solid line) proximate to the bottom portion 4 of the vessel wall 3. Alternatively, the body 6 can be lifted to a position (shown in dash line) proximate to the surface 7 of water pool 1. FIG. 1B depicts a lighter-than-water body 6 which in its quiescent or rest state rises proximate to the surface 7 of water pool 1. Similarly, the body 6 can be caused to descend to the bottom 4 portion of wall 3. As will be discussed hereinafter in connection with FIGS. 2 and 3, the body 6 carries and on-board controller which in FIGS. 1A and 1B, is powered by electricity delivered via flexible wire 9 from an external electric power source 10 for controlling the states of body 6.

[0021] FIGS. 1C and 1D depict pool cleaner installations, respectively analogous to FIGS. 1A and 1B, except without the electric power wire 9. Rather, the body 6 in FIGS. 1C and 1D, carries an on-board electric power source, e.g., solar cells 11 and/or a battery. The battery can be recharged by the solar cell 11 and/or by electric terminals available at a docking station 12.

[0022] The body 6 is essentially comprised of upper and lower portions, 6U and 6L respectively, spaced in a nominally vertical direction, and front and rear portions, 6F and 6R respectively, spaced in a nominally horizontal direction. A traction means such as wheels 13 are typically mounted adjacent the body lower portion 6L for engaging the wall surface 8.

[0023] Embodiments of the invention are based, in part, on a recognition of the following considerations:

[0024] 1. Effective water surface cleaning reduces the overall task of swimming pool cleaning since most debris in the water and on the vessel wall surface previously floated on the water surface.

[0025] 2. A water cleaner capable of floating or otherwise traveling to the same place that the debris floats can capture debris more effectively than a fixed position built-in skimmer.

[0026] 3. A water surface cleaner can operate by using a weir, a water entrainment device, or by scooping up debris as it moves across the water surface. The debris can be collected in a water permeable container.

[0027] 4. A single unitary structure or body can be used to selectively operate proximate to the water surface in a water surface cleaning mode and proximate to the wall surface in a wall surface cleaning mode. A common debris collection container can be used in both modes.

[0028] 5. The level of the body 6 in the water pool 1, i.e., proximate to the water surface or proximate to the wall surface, can be controlled by a level control subsystem capable of selectively defining either a water surface mode or a wall surface mode. The mode defined by the subsystem can be selected via a user control, e.g., a manual switch or valve, or via an event sensor responsive to an event such as the expiration of a time interval.

[0029] 6. The movement of the body in the water pool can be controlled by a propulsion subsystem, preferably operable to selectively propel the body in either a forward or an alternative “redirect” direction. The direction is preferably selected via an event sensor which responds to an event such as the expiration of a time interval or an interruption of the body's forward motion.

[0030] 7. A cleaning subsystem can be operated in either a water surface cleaning mode (e.g., skimming) or a wall surface cleaning mode (e.g., vacuuming or sweeping).

[0031] One or more of the aforementioned subsystems in accordance with the present invention is powered by electricity which is either delivered to the body 6 via a flexible wire 9 (FIGS. 1A, 1B) or produced on-board the body, e.g., by a solar cell and/or battery.

[0032] FIG. 2 shows a block diagram of the functional elements of a preferred body 6 in accordance with the present invention. The elements include a level control subsystem 16, a cleaning control subsystem 18, and a propulsion control subsystem 19. The respective subsystems are powered from an electric power source 20 which can, for example, comprise an external power source (as represented in FIGS. 1A, 1B) connected to the body via a flexible wire, or on-board power sources such as solar cells and/or batteries (as represented in FIGS. 1C, 1D).

[0033] The electric source 20 also powers a system controller 22 which operates to define output modes (e.g., water surface or wall surface) and states (e.g., forward or redirect) in response to user and event inputs. These operating modes and states are discussed at length in applicants' aforementioned parent and related applications incorporated herein by reference. To summarize briefly, the water surface and wall surface modes are alternately defined, typically controlled by a user input or by a timed event. When the controller 22 defines the water surface mode, the level control subsystem 16 places the body proximate to the water surface and the cleaning control subsystem 18 operates to collect water therefrom, as by skimming or scooping. When the wall surface mode is defined, the level control subsystem 16 places the body proximate to the wall surface and the cleaning control subsystem 18 operates to collect water therefrom, as by vacuuming or sweeping. In either case, the collected water is preferably passed through a porous debris collection container which is periodically emptied by the user. Alternatively, the collected water could be directed via a suction hose (not shown) to the pool's main filter system.

[0034] The controller 22 primarily defines the forward state which causes the propulsion control subsystem 20 to move the body 6 in a forward direction along either the water surface or wall surface to effect cleaning. However, in order to avoid lengthy cleaning interruptions, as could be caused by the body 6 getting stuck behind some obstruction, the controller preferably periodically defines the redirect state. Switching to the redirect state can be initiated by a timed event or, for example, by a sensed interruption of the body's forward motion. In the redirect state, a force is produced to move the body rearwardly and/or sidewardly.

[0035] Attention is now directed to FIG. 3 which is a block diagram depicting a preferred implementation of the functional control system shown in FIG. 2.

[0036] The level control subsystem 16 is implemented to modify the effective buoyancy of the body. In a preferred embodiment, a closed fluid chamber 30 containing an air bag 32 is used to modify body buoyancy. The port 34 to the air bag 32 is coupled to an air source 36 which can, for example, comprise an on-board reservoir storing compressed air or a tube extending from the body 6 to a point above the pool surface 7.

[0037] A port 40 selectively either supplies fluid, typically water, under pressure to the chamber 30 or allows fluid to flow out of the chamber, depending upon the pressure at port 42 of level valve 44. The level valve 44 is coupled to pump/motor 46 and is controlled by controller outputs 47, 48. More specifically, hose 49 couples the pressure port 50 of pump/motor 46 to inlet port 52 of level valve 44. Hose 54 couples the suction port 56 of pump/motor 46 to outlet port 58 of level valve 44. Level valve 44 is also provided with a port 60 which is open to pool water.

[0038] A heavier-than-water body 6 can be floated to the surface by extracting water from chamber 30 and allowing the volume of air in bag 32 to expand. In order to extract water from chamber 30, the level valve 44 is operated in the water surface mode commanded by output 47 to couple port 42 to pump/motor suction port 56. In this state, the level valve directs the positive pressure output from the pump/motor supplied to port 52 out through open port 60.

[0039] In the wall surface mode commanded by output 48, water is supplied under pressure to chamber port 40 to force air out of the bag 32, either back into the aforementioned compressed air reservoir or out through the surface tube. To supply water under pressure to chamber port 40, level valve 44 is operated to couple the pressure port 50 of pump/motor 46 to level valve port 42. In this state, port 60 operates as a water source enabling water to be pulled through the level valve and hose 54 into the suction port 56 of the pump/motor 46.

[0040] The two states of the level valve 44 are controlled by controller outputs 47, 48. The energization of the pump/motor 46 is controlled by controller output 64.

[0041] It is preferable that the level control subsystem 16 also include a pressure sensor 66 for sensing the pressure level in the tube between level valve port 42 and chamber port 40. The output of the pressure sensor 66 comprises one of the event inputs to controller 22 to cause it to de-energize pump/motor 46 when the pressure is out of limits. The implementation of the level control subsystem 16 preferably also includes a default mode valve 70. In normal operation, this valve is closed as a consequence of a signal provided by controller output terminal 72. However, in the event of electrical failure, the valve 70 defaults to an open position which can, for example, enable the compressed air source to supply air to the bag 32 to allow the body 6 to ascend, even in the absence of electrical power. If a surface tube is used, air can escape via the tube to cause the body 6 to sink.

[0042] The cleaning control subsystem 18 is implemented by a cleaning flow generator 80, e.g. a propeller which pulls water into the body, as will be explained in greater detail in connection with FIGS. 4-6, and runs it through a porous debris collection container. The cleaning flow generator 80 is driven by the output shaft (and appropriate gearing) of a motor 84. The energization and direction of the motor is controlled by controller outputs 86, 87. Preferred embodiments of the invention include an upper inlet for collecting water from the pool water surface and a lower inlet for collecting pool water from proximate to the wall surface. In order to enable the cleaning flow to be collected from either one surface or the other, a cleaning flow source valve 90 is provided which in controlled by the aforementioned controller outputs 47, 48.

[0043] The propulsion control subsystem 20 is implemented by a propulsion generator 92 which can comprise a propeller, a driven traction wheel, or a nozzle outlet flow. The propulsion generator 92 can be driven by the aforementioned motor 84. The motor 84 can be driven bidirectionally via the aforementioned controller outputs 86 and 87. Thus, by driving the motor 84 in a forward direction, the propulsion generator 92 will produce a flow to move the body 6 in a forward direction. By reversing the motor direction, the propulsion generator 92 will be driven in an opposite direction to redirect the movement of the body, for example to cause it to back up.

[0044] Attention is now directed to FIGS. 4, 5, 6 which illustrate a preferred structural embodiment of body 6 consistent with the aforediscussed block diagram of FIG. 3. The body 6 essentially comprises a rectangular housing 100 supported on multiple traction wheels 102. Front wheels 102F are mounted on a common drive axle 104. Rear wheels 102R are mounted on idle spindles 106. Drive axle 104 is coupled via gear 105 and gear train 110 to output shaft 112 of aforementioned drive motor 84. Drive motor 84 is additionally coupled via shaft 114 and bevel gear 116 to propeller drive shaft 118. When operating in the forward state, shaft 118 drives propeller 120 in a first direction to draw water from propeller chamber 121 to discharge the water rearwardly from opening 122 to produce forward body motion. To operate in the backup or redirect state, shaft 118 drives propeller 120 in a second opposite direction to pull water into opening 122 to discharge it via opening 123 in a forward/sideward direction to produce rearward/sideward motion. To achieve correct directional flow through openings 122 and 123, flap elements F1 and F2 are provided. Flap elements F1 and F2 will be discussed further hereinafter, but at this juncture it is helpful to know that in the forward state, F1 is open and F2 is closed and in the redirect state, F1 is closed and F2 is open. The positions of these elements are determined by the direction of flow produced by propeller 120.

[0045] The body 6 defines an internal cavity which, in addition to housing the motor 84, also accommodates the aforementioned pump/motor 46 and level valve 44. The body 6 also carries the electric power source 20 which, as previously noted, can constitute a solar cell, a battery, or the terminals of a flexible wire extending to an external power source. Additionally, as shown in FIG. 6, the body 6 also houses the aforediscussed controller 22.

[0046] The body 6 is configured to move forwardly along either the pool water surface or wall surface. When at the water surface, forward propulsion is achieved primarily by the outflow produced by rotation of propeller 120. When at the wall surface, forward propulsion is primarily achieved by the driven front wheels 102F.

[0047] The body 6 is configured so that when operating at the water surface, pool water flows over deck 124 as represented by the flow arrows 126. In the water surface mode, the gate 128 (cleaning flow source valve 90 in FIG. 3) is raised to the position shown in dotted line in FIG. 4. As a consequence, surface water 126 will flow into basket 130 through the open basket mouth 132. The inflow 126 into basket 130 will open flap valve 134 which is provided to prevent reverse outflow from the basket 130. The basket 130 preferably contains a removable porous debris collection container or bag 138. The water 126 flowing over the deck 124 into the collection bag 138 leaves its debris in the bag and then passes out through the basket, entering port 140. If in this forward state, the flow moves past open flap F1 and into the propeller supply chamber 121. The propeller 120 operates to pull water from chamber 121 and discharge it rearwardly to provide forward propulsion.

[0048] In the wall surface cleaning mode, gate 128 is closed, i.e. down, and the propeller 120 operates to pull water in from vacuum port 146 proximate to the wall surface 8. This flow travels up passage 148 to enter collection bag 138 via mouth 132. After passing through the bag and basket 130, it flows past open flap F1 into chamber 121 for rearward discharge by propeller 120.

[0049] When in the redirect state, the propeller 120 is rotated in the opposite direction to draw water in via opening 122. This direction of flow acts to close flap F1 to prevent reverse flow through the bracket 130 and bag 138 and open flap F2 is discharge rearwardly and sidewardly from opening 123.

[0050] In order to facilitate movement of the body 6 around obstructions, the body is preferably provided with horizontally oriented guide wheels 160 projecting from its corners. Additionally, a forwardly projecting guide wheel 162 is mounted on bracket 164 hinged at 166 to the body 6. The guide wheel 162 primarily functions at the water surface to engage the pool wall and facilitate movement of the body around obstructions. A caster wheel 170 is preferably mounted beneath the guide wheel 162 for engaging and riding over contoured surfaces when the unit is operating in the wall surface mode.