Patent Abstract:
A swimming pool cleaner discharges water jets under the cleaner body, directed toward its center from its sides, to agitate and lift debris toward one or more vacuum intake openings, to greatly enhance the cleaning ability of the cleaner. The suspended dirt and debris become semi-buoyant under the force of the jetted water which is preferably moving in the same direction as the cleaner, so that the relative speed between the cleaner and the suspended dirt and debris is reduced, thereby enabling the cleaner to move at a relatively faster rate and still clean with equivalent or even greater efficiency than a pool cleaner that is not equipped with directional cleaning water jets. In addition, displaced front and back orientations of the intake ports allow for longer time for any dirt and debris to be picked up.

Full Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
   This is a divisional of prior application U.S. Ser. No. 10/272,754, filed Oct. 17, 2002 now U.S. Pat. No. 6,971,136, which is a Continuation-in Part application of U.S. Ser. No. 10/109,689, filed Mar. 29, 2002, now U.S. Pat. No. 6,742,613, which is a division of U.S. Ser. No. 09/237,301 filed Jan. 25, 1999, now U.S. Pat. No. 6,412,133, the disclosures of which are incorporated herein by reference in their entireties. 

   FIELD OF THE INVENTION 
   This invention relates to hand-powered and self-propelled pool and tank cleaners that draw water containing dirt and debris from the surface beneath the moving pool cleaner for entrainment in a filter. 
   BACKGROUND OF THE INVENTION 
   One of the most common problems that occurs in the disrupting of the efficient operation and pre-determined movement patterns of an automated swimming pool cleaner are discontinuities in and obstacles protruding from the bottom surface of the pool. When a self-propelled cleaner encounters and attempts to pass over or around an obstacle, it can become immobilized, particularly if the obstacle engages the opening of the vacuum intake. One approach to solving this problem has been to design the cleaner so that its baseplate and associated water intake is raised as high as possible from the surface to be vacuumed. However, the higher the intake, the less effective the vacuuming becomes. Debris is also left behind when the cleaner is moving rapidly. To counter these problems, the pool cleaner is programmed to move about its route at a rather sluggish pace. The result is that it may take many hours to clean an average size swimming pool. 
   It has also been proposed to equip the pool cleaner with flexible intake adapters to enhance the surface vacuuming ability of the cleaner. The intake adapters are also subject to being immobilized on steps or other protruding obstacles. 
   A further general problem of effectively and efficiently cleaning the bottom surface exists where the dirt and debris is heavy and/or when the pool has not been regularly cleaned and the movement of water into the intake ports in the bottom or baseplate of the pool cleaner is not sufficient to create the required turbulence at the surface to disturb and lift the dirt and debris into suspension so that it can be drawn to the intake port. 
   SUMMARY OF THE INVENTION 
   This invention relates to an improvement in the cleaning methods and apparatus that overcome the above-described shortcomings of pool cleaners of the prior art, whether hand-powered or of the self-propelled and robotic type. The introduction of water jets under the cleaner body, directed inboard and generally toward its center from its sides, agitates and lifts the dirt and debris, which is then moved toward the one or more baseplate intake ports, to greatly enhance the cleaning ability of the apparatus. The suspended dirt and debris become semi-buoyant under the force and turbulence of the jetted water. 
   In a preferred embodiment, a plurality of the directional water jets moves the debris in the same direction as the cleaner is moving. Thus, the relative speed between the cleaner and the suspended dirt and debris is reduced, enabling the cleaner to move at a relatively faster rate and still clean with equivalent, or even greater efficiency than a pool cleaner that is not equipped with the directional cleaning water jet apparatus. In addition, the front and back orientations of the intake slot allow a longer time for any dirt and debris to be picked up. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-sectional view of a mechanically driven swimming pool cleaner of the present invention; 
       FIG. 2 . is a bottom view of the pool cleaner, taken on lines  2 - 2  of  FIG. 1 ; 
       FIG. 3  is an alternative embodiment similar to that of  FIG. 2 ; 
       FIG. 4  is a bottom view of yet another embodiment of a pool cleaner similar to that of  FIG. 1 . 
       FIG. 5  illustrates a bottom view of yet another embodiment of the invention; 
       FIG. 6  is a side elevation view, partly in cross-section, of another embodiment of the invention utilized with a cleaner that is moved about the pool by water jet propulsion; 
       FIG. 7  is the top plan view of the cleaner taken along lines  7 - 7  of  FIG. 6 ; 
       FIG. 8  is a bottom view of the cleaner taken along lines  8 - 8  of  FIG. 6 ; 
       FIG. 9  is a side elevation, partly in cross-section, of yet another embodiment of the invention; 
       FIG. 10  is a top plan view of the impeller taken along lines  10 - 10  of  FIG. 9 ; 
       FIG. 11  is a top plan view of the impeller housing taken along lines  11 - 11  of  FIG. 9 ; 
       FIG. 12  is a cross-sectional view of a manually propelled pool cleaner in which the water jet delivery tubes are shown partly in section; 
       FIG. 13  is a segment of a cross-sectional view taken along line  13 - 13  of  FIG. 12  showing intake flaps in the open position; 
       FIG. 14  is a view similar to  FIG. 13  in which the intake flaps are in the closed position; 
       FIG. 15  is a cross-sectional view taken along line  15 - 15  of  FIG. 14 ; 
       FIG. 16  is a bottom view of another embodiment of a pool cleaner fitted with the water jet cleaning system of the invention; 
       FIG. 17  is a bottom view of a pool cleaner equipped with a further embodiment of the invention; 
       FIG. 18  is a cross-sectional side elevation view of a further embodiment of the invention; and 
       FIG. 19  is a cross-sectional side elevation view of another simplified embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a first embodiment of a self-propelled robotic swimming pool cleaner implementing the present invention is shown, which includes a housing  1 , an electric motor  2 , a centrifugal pump  3 , connecting tubes  4  and  5 , jet nozzle elbows  6  and  7 , filter bag holder  8 , filter bag  9  and wheels  10  supporting the housing  1 . The self-propelled swimming pool cleaner can include features known to the prior cleaning apparatus which are moved by the directional control of one or more water jets and valves, such as the apparatus described in U.S. Pat. No. 6,412,133 B1, the disclosure of which is incorporated herein by reference in its entirety. 
   As further illustrated in  FIG. 2 , the water jets  30 ,  32 , are supplied by the centrifugal pump  3  and discharged by the jet nozzles  6 ,  7 , respectively, are directed toward the dirt and debris  36  on the pool surface below the baseplate  31 . The baseplate  31  is provided with an oval-shaped aperture forming an intake port  11 . The intake  11  is oriented in a front and a back direction, relative to the longitudinal orientation of the jet streams  30 ,  32 , as illustrated in  FIG. 2 . The streams  30 ,  32  are aimed at the surface below the middle of the intake  11  so that the combined water flow from the streams  30 ,  32  accommodates the intake  11  equally regardless of whether the cleaner moves forward or backward. In either case, the trailing half of the intake  11  is always the working half as the turbulence does not benefit the leading half. When the cleaner moves in the direction shown by arrow A, section A′ of the intake  11  does most of the cleaning. Conversely, when the cleaner moves in the direction of arrow B, section B′ of the intake  11  benefits from the turbulence to draw the suspended debris and dirt into the filter bag. 
   The pool cleaner of this embodiment can also be self-propelled, for example, using discharged water jets from a jet valve housing, such as the housing  22  shown in  FIG. 6  as well as discharged water jets described in the incorporated U.S. Pat. No. 6,412,133 B1, employing the pressure from the discharged water jets to move the pool cleaner in selected directions controlled by water valves or other mechanisms. Alternatively, the wheels  10  can be connected to one or more drive motors for selectively moving the pool cleaner along the surface of the pool being cleaned. The drive motors can be electric or water turbine driven by pressurized water. 
   Although the embodiment shown in  FIGS. 1-2  provides far better results than those of prior art pool cleaners, the performance and efficiency can be further improved, as will be described below. 
   In the second embodiment shown in  FIG. 3 , the one long intake opening of the intake  11  of  FIG. 2  is replaced by two smaller openings  12  and  13 , one of which is always closed, as by a solenoid switch or other means. Thus, the speed of the intake stream as indicated by the arrows can be doubled. 
   With reference to  FIG. 4 , there is shown yet another embodiment in which swiveling elbow jet nozzles  14  and  15  are equipped with fins  16  and  17 , respectively, which automatically change the positions of the nozzles due to the force of the water, or water resistance, as the cleaner changes direction, to thereby always point to the upstream end of the intake  18 . In the angular arrangement of the jet nozzles  14 ,  15  illustrated in  FIG. 4 , water is discharged at a predetermined pressure to move the debris  36  at a velocity that greatly reduces the relative speed between the debris  36  and the cleaner optimally to zero. This permits the cleaner to move at a relatively higher speed while the debris  36  is moved along in the same direction as the cleaner until the debris  36  can be drawn into the one or more intake port(s),  18  in the baseplate  31 . An optional auxiliary pump  33  can also be used to boost the pressure provided by the streams  30 ,  32 . 
   As shown in  FIG. 5 , another embodiment of the pool cleaner is provided with two pairs of directional nozzles  19  and  20  aimed at the front and rear portions of the intake port  21 . A pair of solenoid activated valves (not shown) control the “on” or “off” flow condition of the nozzles  19 ,  20 . In this embodiment, the centrifugal pump  3 , the filter-bag holder  8 , and the filter bag  9  can be positioned external to the pool cleaner. The directional nozzles  19 ,  20  receive the water jet streams from an output tube  40  of the externally located centrifugal pump  3 , and the filter bag  8  receives the intake water and debris  36  via the filter input tube  42 . The centrifugal pump  3  is connected to an external power supply (not shown) by an electrical connector such as an electrical plug  44 . 
     FIG. 6  is a side elevation view, partly in cross-section, of another embodiment of the invention fitted to a cleaner that is moved about the pool by water jet propulsion. In this embodiment, the jet valve housing  22  is tapped at four places  46 ,  48 ,  50 ,  52 , shown in  FIG. 7 , to supply the plurality of water jet streams  54 ,  56  emitted from jet nozzles  58 ,  60 ,  62 ,  64 , respectively, as best shown in  FIG. 8 . Those plurality of water jets function as described above to aid in the movement of dirt and debris  36  toward the intake port or ports in the baseplate  23 . This embodiment operates in the same manner as the cleaner of  FIG. 4 , except that the change from one set of nozzles to the other set, such as the first pair  58 ,  62  of nozzles to the second pair  60 ,  64 , is accomplished automatically in the jet valve housing  22  when the cleaner changes direction. This construction and method of operation eliminates the need for electronics to operate a solenoid controlled valve and provides a simple mechanism to perform the dual functions of directional control change and the flow to selected positions among the plurality of directionally oriented cleaning water jet nozzles  58 ,  60 ,  62 ,  64 . 
   Referring to  FIG. 9 , a propeller pump  24  and a centrifugal pump  25 , functioning as an impeller, are operated by the same motor  26  for use in each of the embodiments shown in  FIGS. 1-5 . The centrifugal pump  25  is designed to have the shape of a cone to provide the least amount of resistance to the water being pumped by the propeller pump  24 . The cone-shaped propeller base  27  also provides easier transition of water going through the impeller housing  28 . The cross-section of the impeller blades of the propeller pump  24  corresponds to the cross-section of an airplane wing. This configuration helps to further limit the drag which the impeller puts on the motor shaft  29 . 
   With reference to  FIG. 10  and  FIG. 11  there is shown the water jet streams  30 ,  32  emitted from output channels  66 ,  68 , respectively, which are connected to the connecting tubes in the various embodiments, such as the connecting tubes  4 ,  5  in  FIG. 1 . Having a centrifugal/impeller pump  25  coupled with a propeller pump  24  is also beneficial for other applications used to control the directional movement of a cleaner. For example, a hydraulic piston, which is normally operated pump powered by a small DC motor to arrest one side of moving cleaner, can be operated without the cost of the DC motor. 
   In  FIG. 12 , there is illustrated in a cross-sectional view, a manually propelled cleaner that is equipped with a bottom or baseplate  76  intake assembly which has a pair of water jet nozzles  70  permanently mounted at its opposite ends. The cleaner is also fitted with a centrifugal pump  3  that is secured to housing  1 . In this embodiment water delivery tubes  4  are positioned inside the housing  1 . Inner ends of said jets are slidably connected to delivery tubes  4  by couplings  74  that are also mounted inside the main housing. 
   Baseplate  76  intake assembly has an elongated slot  11  perpendicular to the direction of the adjacent water jets. Inside, covering said slot  11  are a pair of flaps  78  that open when suction pump  2  is on and close when power is turned off. 
     FIG. 13  illustrates a double pivot hinge mechanism having an “L” shaped hinge transfer member  80  connected to each flap  78 . This allows the flaps to lift off said slot  11  higher at their hinged ends than would otherwise be possible. This relationship and the functioning of the hinge members  80  are further illustrated in  FIG. 14  where the flaps are shown in closed position. In the embodiment of  FIGS. 12-15 , the cleaner is manually propelled by handle  71 . 
   In the interior cross-sectional view of  FIG. 15 , the flaps  78  are shown in the closed position, each flap supported by a single hinge member  80 . As, will be understood by one of ordinary skill in the art, two or more hinge members  80  can be employed should the size of the intake  11  and/or flaps  78  be increased. The pivot means  82  permit the flaps to move easily in response to the water pressure during flow to settle in the closed position. 
     FIG. 16  is a bottom view of another water jet assisted cleaner that is equipped with a conventional baseplate intake assembly in which the major axis of the intake slot is parallel to the direction of their respective associated water jets. Although the direction of said slots are not in an optimum angle (front and back), the cleaning efficiency is still greatly increased when water jets are introduced to assist in raising the dirt and debris into suspension below the moving cleaner. 
     FIG. 17  is a bottom view of yet another cleaner in which the intake slot is perpendicular to the movement of the cleaner and a pair of manifolds  100  are located parallel to said intake slot  11  in the front and back ends of the cleaner to provide multiple jet streams through a number of small water jet discharge openings  102  along the length of said manifold, aiming slightly down, but mainly toward said intake slot  11 . In this embodiment, the single intake slot  11  extends substantially across the baseplate. A pair of valves  104  control the water flow from centrifugal pump  3  so that only the trailing manifold is activated, sweeping the debris forward, along with the moving cleaner, until it is picked up with water drawn into the intake slot  11 . In a preferred embodiment, each of the discharge openings  102  is provided with a low friction fitting to minimize the back pressure in the system and enhance the turbulent effect of the water stream to suspend dirt and debris. 
   An additional benefit of this arrangement is that the cleaner can clean very close to a sharp-cornered vertical pool wall. Although the plurality of water jet streams trail the moving cleaner, when said cleaner stops at the wall and reverses its direction, the trailing manifold begins sweeping the swimming pool floor close to the vertical wall. 
   In another embodiment of the manifolds of  FIG. 17  (not shown), of the control valves, are omitted, leaving open the flow path to both delivery tubes and manifolds. Although the front water jets will be sweeping the debris backwards against the directional movement of cleaner, the rear water jets sweeping forward trap debris under intake port  11  until it is picked up. 
   Referring to the embodiment of  FIG. 18 , valves controlling the water jet manifolds are replaced by solenoids  110  which automatically turn a pair of swiveling manifolds  100  so that the leading manifold&#39;s water jets  102  are aimed substantially downward, stirring up the debris, while the trailing manifold&#39;s water jets are aimed substantially forward, sweeping the debris along with the moving cleaner. Both manifolds are open at all times. 
   With reference to  FIG. 19 , there is illustrated an embodiment in which both manifolds  100  are in a fixed position with their water jets aimed substantially downward. Although this fixed positioning of the water jets may not be as efficient in cleaning as those described above, it will outperform prior art cleaners that are not assisted by water jets. The elimination of electronics components that are necessary to operate solenoids and/or other automatic switching mechanisms makes this embodiment of the invention particularly cost-effective to produce. 
   There are other benefits and advantages from the embodiments illustrated and described above that will be apparent to those skilled in the art.

Technology Classification (CPC): 4