Abstract:
A rotating or oscillating brush is brought up against an underwater surface to be cleaned. The surface may be the hull of a boat or inside walls of an aquarium. While the brush moves, the apparatus is held against the surface by suction. There is a suction pump which pumps water from the apparatus to above ground or elsewhere. The suction creates force of the apparatus against the surface for good cleaning. It is ordinarily difficult to get good force against the surface since the water may be deep and there is nothing for the operator or the apparatus to push against. Debris from cleaning is drawn away from the cleaning area. Wheels or pads or a rubber skirt are used to avoid damaging the surface from too much force. A flexible skirt minimizes water leakage past the apparatus and allows conformation to rounded shapes such as boat hull. The motor to drive the brush may be electric, or may be hydraulic, or may use the suction pressure as a source of energy. The suction pump may be separate or may be driven by the same motor driving the brush.

Description:
SUMMARY DESCRIPTION  
         [0001]    A rotating or oscillating brush is brought up against an underwater surface to be cleaned. The surface may be the hull of a boat or inside walls of an aquariurm While the brush moves, the apparatus is held against the surface by suction. There is a suction pump which pumps water from the apparatus to above ground or elsewhere. The suction creates force of the apparatus against the surface for good cleaning. It is ordinarily difficult to get good force against the surface since the water may be deep and there is nothing for the operator or the apparatus to push against. Debris from cleaning is drawn away from the cleaning area. Wheels or pads or a rubber skirt are used to avoid damaging the surface from too much force. A flexible skirt minimizes water leakage past the apparatus and allows conformation to rounded shapes such as boat hull The motor to drive the brush may be electric, or may be hydraulic, or may use the suction pressure as a source of energy. The suction pump may be separate or may be driven by the same motor driving the brush.  
           [0002]    Further, the subject system cleans underwater objects such as the bottoms of boats and the sides of aquariums. There is a rotating brush, powered by a motor. Both may rotate on the same shaft, or there may be an intervening gear box to optimize the relative speeds of the two. The brush rotates against the surface to be cleaned, or as an alternative is an oscillating brush.  
           [0003]    The brush is housed within a bell shaped frame, the open end of which faces the surface to be cleaned. Leading from the bell is a tube which connects to an exhaust pump. The exhaust pump pulls water from the bell and water enters the bell from near the surface to be cleaned. The effect is for the bell to move towards the surface. Thus the pressure of the brush on the surface, needed for cleaning, is provided by the suction action of the exhaust motor.  
           [0004]    The motor driving the brush in one form is electrical and capable of operating under water. It may be of the type used for electric propulsion of small boats for fishing when doing what is known as trolling. The motor uses a safe low voltage, 12 volts or 24, so there is no shock hazard.  
           [0005]    In a convenient form, it is powered from a battery attached to the motor. An operator using the equipment underwater controls the motor brush and propeller speed through controls on the motor assembly, or by communication by either wire or radio to the above water power source. The motion of the cleaning brush may be rotary, or may be linear, with a reciprocating motion.  
           [0006]    To avoid excessive pressure of the apparatus against the surface, which hinders lateral motion, there are pressure release flaps on the sides of the bell.  
           [0007]    An alternative configuration is to use a roller rather than a circular brush, with an abrasive surface, resembling an upright vacuum cleaner.  
         BACKGROUND  
         [0008]    Underwater surfaces pick up a variety of undesired plant and animal growths, including barnacles. These growths slow down a boat, obscure viewing through aquarium windows, and cause water pollution. Some harbors have stringent pollution laws which prohibit debris from the surface of the boat hull from entering the harbor waters.  
           [0009]    Cleaning is most typically by mechanical scrubbing. Pressure against the surface plus scrubbing motion is needed. Pressure against an underwater surface is sometimes difficult because there is no convenient floor to push against. Pushing from the dock side is awkward and is necessarily done at the adverse end of a long lever arm.  
           [0010]    There have been many efforts to make easy underwater cleaning of boats, and cleaning of aquarium walls. See reference 2. Some have put brushes on long handles, with a bend in the handle to adapt to boat hull curvature. Other efforts have been to use a flow of water through a turbine or impeller to dive a rotating brush under water. The rotating brush provides some of the necessary scrubbing action. There is still a problem of applying adequate pressure. In another system a jet of water squirts or jets away from the surface, applying pressure towards the surface. One problem with this jet system is that, as the brush is moved to lower depths, perhaps four to ten feet down, the ambient water pressure increases, and there is back pressure, so that the brush rotates more slowly. The reactive jet water flow squirting pressure is reduced, frequently rendering the system unsatisfactory. Another way to get pressure towards the surface is to use a venturi effect to cause suction against the surface, but this is also unsatisfactory owing to the back pressure increasing with depth, and with flat surfaces, not cylindrical the venturi effect is very weak. Further, the jet action stirs the water, causing opacity of the water, and spreading the waste products.  
         PRIOR ART AND PRIOR ART PATENTS  
         [0011]    1. Application Ser. No. 09/659,407 by Charles Walton, (Docket ID 146) for pond and aquarium underwater surfaces cleaning.  
           [0012]    2. Patent references: There were 19 patents cited with regard to the above application, q.v. The list is attached.  
           [0013]    3. Application Ser. No. 110/340774 (Docket ID151 by Charles Walton) shows a propeller system to provide pressure to bring together the surface and the rotating or moving brush. 
       
    
    
     BRIEF DESCRIPTION OF FIGURES  
       [0014]    [0014]FIG. 1. Underwater cleaning system using an electric motor to drive the brush, with a separate suction pump to draw water from a bell shape housing surrounding the brush.  
         [0015]    [0015]FIG. 2. Cleaning system using an electric motor to drive the brush, and the same motor to drive a suction pump inside the unit, and provisions for moving the brush towards or away from the surface, and a speed change system.  
         [0016]    [0016]FIG. 3. Cleaning system in which the flow induced by a separate suction pump also powers the brush.  
         [0017]    [0017]FIG. 4. Underwater Cleaning system using an abrasive roller and a suction pump. 
     
    
     DETAILED DESCRIPTION  
       [0018]    Refer to FIG. 1. There is a bell, or yoke,  10  with its open end brought against the surface  12 . The surface  12  carries some unwanted material  14 , such as algae, barnacles, snails, or mud. The bell  10  also supports a bearing  16 , with shaft  18  carrying brush  20 . The other end of shaft  18  is driven by motor  22 . On brush  20  are multiple scrubbing bristles  24 . The bell  10  is held a short distance away from surface  12  by multiple wheels  26 , mounted on the lips  28  of bell  10 . In lieu of wheels  26  the bell lips  28  may carry a non scratching protection, such as a rubber lip. The lip  28  also supports a skirt  32  or flange. Skirt  32  constrains the flow of water,described later, between the bell  10  and surface  12  and maximizes the suction effect, to be described later.  
         [0019]    There is an external suction pump  38 , which may be above or below the water level. When suction pump  38  is operating, water flows as follows. Water enters under the flexible skirt  32 . It next flows under the bell tips  28 , and through holes in brush  20 , and around the outside of brush  20 . Water flows through holes  34  in the bell  10  and tube  36 . Tube  36  in turn is connected to the suction pump  38 . When pump  38  operates the flow is as described and water is drawn from the bell and is exited to another location from nozzle  40 , along with the debris  14  scrubbed free by brush  20 .  
         [0020]    Refer next to FIG. 2. In this figure new members are introduced, namely a local (bell mounted) suction impeller  82 , a gear box speed changer  78 , and an axial slip drive allowing axial brush motion while still delivering rotating power to the brush The primary elements of FIG. 1 are repeated, namely the brush  20 , bristles  24 , tips  28 , skirt  32 , and motor  22 . The bell  50  carries more members than bell  10 . There is a fluid permeable plate  52  which supports shaft  18  with bearing  54 . Bearing  54  supports the brush, and has the additional capability of allowing axial travel of the brush The purpose of axial travel is given later.  
         [0021]    Shaft  18  is driven rotationally from a power coupling unit formed of housing  56  and follower  58 . Housing  56  is driven by shaft  60 , to be discussed later. Housing  56  drives the rotation of follower  58  in the following manner. There are matching slots in both housing  56  and follower  58 . Riding in the matching slots there are rectangular strips, known as splines, between the housing  56  and follower  58 . The spline mechanism is known in the art and the splines are not shown. The result is one to one coupling in rotation, yet follower  58  can move axially while this rotation occurs. Follower  58 , shaft  18 , brush  20 , all move together axially, while being driven rotationally by housing  56  and shaft  60 .  
         [0022]    To move the brush  20  and follower  58  axially, there is a dual washer plate element  62 , attached rigidly to shaft  18 . A control bar  64  fits between the washer plates. The bar  64  applies pressure to element  62  to move it axially, while still allowing shaft  18  to rotate. Thus the pressure of brush  20  against surface  12  is controlled. Spring  66 , which has provisions for adjustable tension not shown, also applies force to bar  64 , to control the brush pressure. Bar  64  pivots on point  68  so that pressure by an operator on the remote end of bar  64  will also control pressure of the brush  20  against surface  12 .  
         [0023]    Axial travel of the brush allows adjustment of the pressure of the brush against the surface  12 . This adjustment is important in several ways. The pressure need will vary according to the stubbornness of film  14 , and according to wear of the bristles  24 , and the degree of flex of the skirt  32 . Further, if the operator wishes to break the pressure of the brush against the surface, added axial extension lifts the skirt  32  higher and the pressure towards the surface is brought to practically zero.  
         [0024]    Brush pressure adjustment is convenient for situations where the apparatus is be moved from one working area to another. The operator applies sufficient brush pressure to lift the bell, fully releasing the suction, making movement easy. Further, when the apparatus is pointed in the direction of motion, the suction effect make propulsion to a new area more easy. Changes in brush pressure are also helpful and needed when dealing with curving portions of a boat hull.  
         [0025]    On the other end of shaft  60  is a second support bearing  72 . Bearing  72  is carried by a water permeable structure  74 . Water passes freely through  74  via multiple holes  76 . Shaft  60  is also the output shaft of speed changer  78 . Speed changer  78  is most typically of the form of a double gear pass, examples of which are found in swimming pool cleaners to drive the wheels, and is depicted in more detail in reference 1 of this application.  
         [0026]    The input shaft of the speed changer  78  is drive shaft  80 . Shaft  80  is driven by and supported by the output of impeller  82 . Impeller  82  is the rotating part of a water pump formed of impeller  82 , housing  50 , and exit point  84 . The input end of impeller  82  is supported by shaft  80  extending into bearing  86 . The further extension of shaft  80  is into drive motor  22 . Drive motor  22  rotates impeller  82  which then pumps water from bell  50  to output pipe  88  and to the exhaust motor  90 .  
         [0027]    Water is thus drawn from the underwater surface  12  into the bell  50  at its open end, passing lips  28 , and exits via exhaust pump  90  from exhaust point  92 . Water is moved in this direction from one or both pump  90  and the pump formed of motor  22  and impeller  82 .  
         [0028]    The RPM of the pump formed of motor  22  and impeller  82  is relatively high for good pumping action, whereas scrubbing action typically needs less speed but more torque, hence the speed changer  78  optimizes both speeds and torque. An alternative to speed changer  78  is to use a separate motor for pumping and for brushing.  
         [0029]    For the below water electric motor, power cables, not shown, are brought from above water and are attached to the exhaust hose, forming an umbilicus to the apparatus.  
         [0030]    Refer next to FIG. 3. This configuration has the advantage of not requiring an underwater electric motor. The primary elements of FIG. 1 repeat, namely the brush  20 , tips  28 , skirt  32 , and the same general flow of water from skirts  32  to exhaust  92 .  
         [0031]    There is the same flow of water into the bell  100  from the surface  12 . The source of rotary power is different. There is a rotor  106  bearing panels or vanes similar to the vanes on a water wheel or water turbine. The rotor is supported by bearings  54  and  108  on shaft  18 . The water passes through brush  20  as in the previous figures. As the water exits from brush  20  it is constrained by surface  101  to flow through guide pipes  102  and  104  to nozzles  110  and  112 . Nozzles  110  and  112  drive vaned rotor  106 , in the manner of a water turbine. Vaned rotor  106  drives the brush  20  for the desired cleaning action. From rotor  106  the water exits via pipes  114  and  116  to exit pipe  88  and exhaust pump  90  and exhaust nozzle  92 .  
         [0032]    The brush  20  in FIG. 3 has added vanes, giving it both a propeller type action and rotary pump action, both increasing the water flow from the surface  12  and increasing debris  14  flow through the brush  20  to the exhaust  92 , and also increasing the suction pressure upon the surface  12 .  
         [0033]    The rotary motion of the brush  20  gives rotary direction to the water flow. To cooperate with this rotary action, the flow elements  102  and  104 , in cooperation with nozzles  110  and  112 , are tilted in the direction of the rotary action of the brush  20  and rotor  106 . With the tilt the water impinges upon the vaned rotor  106  with increased velocity, with consequent performance improvement.  
         [0034]    Nozzle  110  is oriented to drive the turbine blades on turbine  106  toward the viewer, indicated by a circle with a dot inside, representing the front end of an arrow. Nozzle  112  is oriented to drive the turbine blades away from the viewer, indicated by a circle with a cross inside, representing the rear end of an arrow.  
         [0035]    Shaft  18  has freedom to move axially through bearings  54  and  108 , so that the proximity of brush  20  to surface  12  can be adjusted axially, and the pressure of the brush against surface  12  can be adjusted, typically by applying pressure to the external end of shaft  18 . Shaft  18  is moved axially in the manner shown in FIG. 2. This dual washer structure is not repeated in FIG. 3. Under certain conditions and proportions of brush area, horse power, impeller size, orifice size, and viscosity, the optimum RPM of the brush is not the same as the optimum RPM of the pumps or impellers. In such a case, the remedy is a speed changing gear box between the impeller and brush  
         [0036]    Refer next to FIG. 4. In this system the rotary brush  20  is replaced by a roller brush  124 , in the form of a cylinder bearing bristles or similar abrasive surface. The power drive is a motor  122  using a power transfer belt  126 . The housing  120  is rectangular in shape and is modified from bell shaped housings  10 ,  50 , and  100  to accept this roller configuration. Certain hull shapes are more easily cleaned with this linear configuration.  
         [0037]    Variations  
         [0038]    1. To accomplish brush to surface pressure adjustment, an alternative way is to mount the motor and shaft on bearings which slide axially, carrying the brush, towards or away from the surface.  
         [0039]    2. A second way to adjust brush pressure against the surface, not shown, is to raise and lower the skirts or flange around the bell adjacent to the surface to be cleaned. A third way, not shown, is to raise and lower the wheels which position the bell height over the surface to be cleaned.  
         [0040]    3. An alternative way to drive the brush while allowing axial motion is that, rather than a splined shaft, the last drive gear and its pinion, are made overly thick in the axial direction, so that torque is transmitted, even as the brush shaft moves axially. Axial movement allows achievement of various applications of surface pressure.  
         [0041]    4. Not shown are mechanical provisions for driving an oscillating brush rather than a rotary brush. For back and forth oscillation, mechanical cranks or an offset cam will provide oscillating action, or other devices known to mechanical engineers skilled in the art. The oscillation action is preferred by some boat owners because residual cleaning streaks are all oriented in the direction of motion of the boat, and thus offer a slightly reduced drag over the surface.  
         [0042]    5. Lateral motion of the entire apparatus, while cleaning a surface, can be accomplished by the operator tilting the bell, away from the desired direction of lateral motion. The tilt of the bell will cause the edge of the bell facing in the desired direction to lift, and there is then greater input flow from the lifted side than the low other side, and there will consequently be greater pull in the direction which has been lifted. Alternatively, lateral or sideways motion is accomplished by selectively opening valves in the sides of the bell, opening a valve in the side towards which motion is desired. The sideways suction aids sideways motion.  
         [0043]    6. To adapt to curved boat hulls, the bell may be made into more than one solid piece. There will be multiple flaps on the side of the bell which can pull back from projection or curves, and return to normal when the underwater surface being cleaned is more regular. The bottom part of the bell is made of rubber, to conform to hull shapes.  
         [0044]    7. The brush may be driven through a flexible shaft from a remote location. The motor may be powered by air, or powered by hydraulics.  
         [0045]    8. Under certain combinations of surface quality, brush pressure, and water pressure, the pressure or suction toward the surface can become excessive, making lateral movement difficult. The unit will seem to bond to the surface. The remedies for this difficulty are several, one of which is to have release valves in the side of the bell. The internal suction is reduced when the relief valves are open. The opening of the valves is under manual control, or is spring operated, or other automatic control, related to pressure and lateral mobility. For example, if lateral motion is detected to be stiff, then by excess pressure required on the handle, the side valves will automatically open, or the bottom wheels will lift the assembly.  
         [0046]    9. The skirt may be larger than shown, and the bottom (surface  12  side) part of the bell may be highly flexible and extend upward (axial direction) to a large percentage of the bell sides. The bell will then more flexibly adapt to various boat hull shapes.  
         [0047]    10. The skirt may be formed of a large number of rubber fingers, also adaptable to boat bottom shapes, and passing water with some resistance to the bell.  
         [0048]    11. The system can be configured in the manner of the classic upright vacuum cleaner, as described in FIG. 4. The brush scrubbing element is a roller, rather than a flat circular brush surface. The debris is collected while scrubbing and sent upwards to a large bag, which filters out the debris and exhausts the water. The scrub marks of such a system are parallel, rather than circular, and will aid the speed of a boat.