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CROSS REFERENCE TO RELATED APPLICATIONS 
     This Application is a continuation of application Ser. No. 09/113,832, filed Jul. 10, 1998, now U.S. Pat. No. 6,119,293 which itself is related to Provisional Applications having Ser. No. 60/052,296, filed on Jul. 11, 1997 for “Steering Apparatus and Method for Pool Cleaner” and Ser. No. 60/052,625, filed Jul. 15, 1997 for “Submerged Surface Cleaning Device,” all of which are commonly owned with the instant application. 
    
    
     FIELD OF INVENTION 
     This invention relates generally to self-propelled devices for cleaning submerged surfaces. More particularly, it relates to a swimming pool cleaning device incorporating a flow control valve for establishing intermittent flow of a fluid through the cleaner and a rotating mechanism to assist the cleaner to steer away from obstructions and avoid repetitive patterns of travel across the surface to be cleaned. 
     BACKGROUND OF INVENTION 
     Mechanical pool cleaners which utilize the flow of water drawn through the cleaner by means of a connectable flexible suction pipe in communication with a filtration system pump are well known. Such pool cleaners are termed suction cleaners. Some suction cleaners interrupt the flow of the water induced through at least one passage through the cleaner to provide the propulsive force to move the cleaner in a random manner across the surface to be cleaned. 
     In U.S. Pat. No. 3,803,658 to Raubenheimer discloses a cleaning device which employs a water cut-off valve carried in rotational movement by a wheel driven by the flow of liquid through the cleaner. As is typical for a suction cleaner, a flexible hose leads from the suction chamber of the device to the suction side of the filtration system pump. When in use for cleaning a swimming pool, the hose becomes filled with water and the continuous opening and closing of the valve causes the hose to jerk. As the suction against the surface to be cleaned is momentarily released each time the gate closes, the jerking movement of the hose causes the head to move over the surface. 
     A water interruption pool cleaner developed by Chauvier and described in U.S. Pat. No. 4,023,227 uses the oscillatory movement of a flapper valve of substantially triangular cross-section displaceably located in the operating head of the cleaner and between two valve seats to alternately close off the flow of water drawn through a pair of passages in the cleaner which is connected by means of a suction pipe to the filtration system pump. The passages are located parallel to each other and are preferably oriented at an angle of 45° from the surface to be cleaned. The sudden halt of the flow of liquid through one passage applies an impulsive force to the apparatus due to the kinetic energy of the fluid flowing in the passage. This impulsive force is sufficient to displace the pool cleaner along the surface to be cleaned. Further, due to the inertia of the liquid in the passage to which flow is transferred, the pressure differential between the low pressure in the head and the ambient pressure of the water surrounding the cleaner is temporarily reduced, thereby decreasing the frictional engagement between the head of the pool cleaner and the surface, allowing the cleaner to be displaced. 
     By way of further example, water interruption pool cleaners which are more compact than the Chauvier device described above are disclosed in U.S. Pat. Nos. 4,133,068 and 4,208,752 issued to Hofmann. They employ an oscillatable valve adapted to alternately close a pair of passages in the head of the cleaner. A baffle plate is disposed in the head between the inlet and valve to cause one of the passages to be more restricted and less direct between inlet and outlet. 
     U.S. Pat. Nos. 4,682,833 and 4,742,593 to Stoltz and Kallenbach respectively, achieve autonomous water interruption by providing an assembly including a tubular flow passage at least partly defined by a transversely contractible and expandable tubular diaphragm, the tubular flow passage and tubular diaphragm are enclosed within a chamber formed by the body of the cleaner. The assembly includes means whereby pressures internally of the tubular diaphragm member and externally of tubular diaphragm member within the chamber formed around the member by the body are controlled so that, in use with fluid flowing through the diaphragm, it will be caused to automatically and repeatedly contract and expand. A pulsating flow of fluid through the assembly results and in forces cause the displacement of the pool cleaner apparatus over a surface to be cleaned. 
     To effect interruption of an induced flow through a swimming pool cleaner, U.S. Pat. No. 4,807,318 to Kallenbach discloses a tubular axially resilient diaphragm located within a chamber. One end of the diaphragm is closed and adapted to hold normally closed a rigid passage from the head of the pool cleaner to the usual form of suction pipe which connects the pool cleaner to the filtration unit. The diaphragm and its closed end also provide means for subjecting the interior of the diaphragm to variations in the pressure of water flow through the cleaner during use. 
     U.S. Pat. No. 4,769,867 to Stoltz describes a water interruption pool cleaner having a passage there through from an inlet end to an outlet in communication with a suction source. A valve in the form of jaw-like members is located at the fluid intake end of a rigid tubular section within a passage of the cleaner. In response to an induced flow of water through the valve and the tubular section, the jaw-like members automatically move relative to each other about an axis transverse to the length of and adjacent the end of the tubular section. The members are tapered towards each other to an inlet between them at their free ends with flexible membranes located between the sides of the jaws. 
     In another pool cleaner invention described in U.S. Pat. No. 4,817,225 to Stoltz, water interruption is achieved by means of a spherical closure member which is free to move in the head of the cleaner towards and away from a closure valve seat located at the upstream end of the outlet from the head. A hollow axially contractible resilient member is connected to the outlet at one end with its other end is connected to a flexible suction pipe. 
     U.S. Pat. No. 5,404,607 to Sebor for a Self Propelled Submersible Suction Cleaner uses an oscillator pivotally mounted within the flow path of a suction chamber to cause abrupt changes in water flow and thereby impart vibratory motion to the housing. Shoe means incorporating angled tread elements cooperate to move the housing along a forwardly direction of travel in response to the vibratory motion. Means are provided for converting a reciprocal angular movement or to and for movement of the oscillator to an angular movement in one direction for purposes of driving a shaft. To enable the Sebor &#39;607 cleaner to turn at established intervals throughout its travel over the surface to be cleaned, a drive gear is affixed to the shaft and engages a gear train which, in turn, engages a rotatable coupling at defined intervals to generate rotation of the coupling at these defined intervals. When in use, the rotatable coupling is connected to a flexible suction hose in communication with a filtration system pump. 
     Typically, a flapper valve used in such devices emit a hammering sound which can be irritating to a user. By way of example, if the swimming pool is located close to a building, the sound may resonate through the structure and be audible inside the rooms. Many devices known in the art are large and cumbersome. This impairs its maneuverability and effectiveness in smaller-sized pools and those where the transitions between the walls and/or between the floor and walls are sharp or tight. Debris such as twigs, berries and stones may become trapped in the operating head between the flapper valve and the valve seats. In order to clear debris or perform other maintenance tasks, it is difficult to gain access to the valve chamber, the flapper valve, valve seats and the openings in communication with the passages. 
     Sticks and larger pieces of debris may damage or puncture the flexible tubular member or may become entrapped in the members. Access to and removal of the flexible tubular member which is enclosed within a chamber is difficult and typically a non-technical person will avoid attempting easy repair. Replacement of the member may require tools which a typical homeowner may not have or be comfortable using. Often times, the pool cleaner provides a strong suction for effectively moving over the surface to be cleaned, but to its detriment fails to create a suction flow through the cleaner sufficient to remove sand located on the surface to be cleaned. 
     SUMMARY OF INVENTION 
     In view of the foregoing background, it is therefore an object of the present invention to provide a device for cleaning submerged surfaces such as those found in swimming pools. In particular, it is intended that the device is minimally intrusive with regard to both noise and overall size, is functionally and mechanically simple, is easy to install, is less prone to entrap debris than existing devices, incorporates easy access to the suction chamber for the removal of entrapped debris and includes means for maneuvering away from obstacles. Yet another object of the invention is to provide steering for directing the cleaning device on the submerged surface to maneuver away from obstacles. Further objects and advantages of the invention will become more apparent from a reading of the following description of the invention and embodiments thereof. It is also contemplated that the system and method are useful in fluid environments other than swimming pools and spas. 
     According to the invention, there is provided a device for cleaning surfaces submerged in a liquid. The device includes a housing in communication with a suction pump and motor by means of a flexible elongated hose connected to a coupling located at an exit end of the device. The coupling is rotatable in a preferred embodiment. The cleaning device incorporates at least one suction chamber or flow passage comprising an entrance end in proximity to the submerged surface to be cleaned and an exit end communicating with the coupling. The axis of a passage through the chamber is angled in a forward direction of travel with respect to the surface to be cleaned. A flow control valve is provided within the chamber or flow passage to cause, upon application of suction flow through the chamber, an automatic, repetitive interruption of the fluid flow therethrough, and thereby resultant forces capable of propelling the cleaner forward in the general direction indicated by the exit end of the chamber and the hose coupling. 
     The suction chamber comprises at least two sides, a front wall and a rear wall. The front wall is generally lateral to the direction of travel of the cleaner. To provide access to the inside of the chamber and the flow control valve, at least a portion of a wall or a side is detachable from the remainder of the chamber. 
     The flow control valve comprises at least one flap member mounted within at least one suction chamber. The flap member comprises two ends, two sides, a front face, a rear face, and at least one substantially rigid portion engaging the flexible portion. In a preferred embodiment, the flexible portion comprises resilient rubber-like material. Alternately, the flexible portion comprises multiple components or materials (including non-resilient materials) in a cooperative arrangement designed to perform the function of the flexible portion. Each end of the flap member is mounted between two sides of a suction chamber about axes generally transverse to the flow of liquid through the chamber. The flap member and the chamber in which it is mounted are dimensioned such that at least two sides of the flap member remain in close communication with at least two sides of the chamber. A substantially rigid portion of the flap member is pivotally mounted closer to the exit end of the chamber and away from both the front and rear walls. A flexible portion of the flap member is mounted closer to the chamber entrance end and attached to or in close proximity to the rear wall of the suction chamber. At least a portion of the flap member must be capable of travel into a position of close proximity or contact with the front wall of the chamber to thereby substantially close the passage through the chamber between the front wall of the chamber and the front face of the flap member. The dimensions of the chamber and the rigid and flexible portions of the flap member as well as the positions in which the flap member portions are attached within the suction chamber, will in combination determine the rate and intensity of interruption of fluid flow through the chamber. 
     When the suction pump is activated, it causes a flow of fluid through the chamber and primarily through a first passage between the front face of the flap member and the front wall of the chamber. The flow through this passage will cause the flap member to be drawn to a position in close proximity or contact with the front wall of the chamber. This action will substantially close the first passage, substantially interrupt the flow of fluid through the first passage, and cause a quantity of water to impact a front face of the flexible portion of the flap member. Restricted flow of fluid will occur between a side of the flexible portion and a wall of the chamber and then via a second passageway between a rear face of the flap member and a rear wall of the chamber. In this manner, the flexible portion acts as a baffle to water flow through the second passageway. Simultaneous with the interruption of fluid flow, the action of the pump will cause a lower fluid pressure zone in the suction hose and in the volume of the chamber downstream of a flexible portion of the flap member. The impact of fluid on the front face of a flexible portion and the lower pressure impinging upon the rear face of a flexible portion of the flap member each cause the flexible portion to deflect towards the lower pressure zone. This action upon and of the flexible portion will apply leverage to the rigid portion and cause the rigid portion and remainder of the flap member to pivot away from the front wall of the chamber, thereby reopening the passage for fluid to be drawn through the chamber. This sequence of events is repeated for as long as the pump is in operation, and causes an automatic reciprocating movement of the rigid portion of the flap member and a regular interruption in fluid flow through the suction chamber for providing a forward movement of the pool cleaner along the surface to be cleaned. 
     In a preferred embodiment, the flexible portion comprises two lengths of resilient rubber-like material separately mounted closer to the chamber entrance and the attached to or in close proximity to the rear wall of the suction chamber. This arrangement provides a volume between the two flexible portions and the walls of the chamber. The sides of the flexible portions are in close proximity with at least two walls of the chamber thereby enabling the flexible portions to perform as baffles and restrict the flow of water from said volume and the flow passage through the chamber. At least one aperture in a section of the wall of the chamber may be provided to allow, when the cleaner is submerged in a liquid, communication between water contained in said volume and water outside of the chamber. During operation of the device, this arrangement provides a buffer zone of relatively higher pressure impinging on one face of each length of flexible portion, the other face of each such flexible portion being in contact with water at a lower pressure as it is drawn through the chamber towards the hose and suction pump. This arrangement significantly diminishes the propensity of water-borne debris to become lodged between a side of a flexible portion of the flap member and a wall of the chamber which would impair operation of the flap valve. 
     Sealing means is attached to the rigid portion of the flap member to minimize the flow of water between the sides of a rigid portion and the walls of the suction chamber. The head of the cleaner is connected to surface engaging means such as a detachable shoe suitable for engaging the surface to be cleaned and for supporting the head. To improve the ability of the cleaner to orient the surface engaging means against the surface to be cleaned, floats and weights are attached to parts of the cleaner. To improve the suction grip of the cleaner to the surface to be cleaned, a flexible sealing flange is detectably connected to the shoe. In a preferred embodiment, at least one aperture is provided in the sealing flange such that water and debris may be drawn through the aperture from the upper surface of the sealing flange and then into the entrance end of the suction chamber proximate the surface to be cleaned. 
     To enable the cleaner to maneuver away from obstacles, the cleaning head may be rotatably attached to the ground engaging means. Automatic means are provided to continuously or intermittently positively rotate at least a portion of the body of a swimming pool cleaner in at least one direction relative to the surface engaging means of the cleaner. Yet further, means are provided to automatically rotate the body of a swimming pool cleaner in a first direction and then another direction relative to the surface engaging means of the cleaner. 
     To assist the steering, improve maneuverability of the cleaner and help avoid the establishment of repetitive courses across the surface to be cleaned, the sealing flange includes at least one out of round side and/or finger and/or stiffening means suitable for engaging a swimming pool wall or obstacle while the surface engaging means are engaged with the floor of the swimming pool. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment, as well as alternate embodiments, of the invention is described by way of example with reference to preferred embodiments in which: 
     FIG. 1 is a perspective view of a swimming pool cleaner according to the present invention operative within a swimming environment; 
     FIG. 2 is an exploded perspective view of the embodiment of FIG. 1; 
     FIG. 3 is a partial cross section view of the embodiment of FIG. 1, illustrating a fluid flow through the embodiment of FIG. 1; 
     FIG. 4 is a partial perspective view of the invention used in a swimming pool environment; 
     FIG. 5 is a forward top perspective view of an alternate embodiment according to the present invention; 
     FIG. 6 is a top rear perspective view of the embodiment of FIG. 5; 
     FIG. 7 is an exploded perspective view of the embodiment of FIG. 5; 
     FIG. 8 is a partial perspective view of a top rear portion of the present invention; 
     FIG. 9 is a partial cross section and exploded view illustrating a removable housing top wall feature of a preferred embodiment; 
     FIG. 10 is a partial cross section view illustrating an alternate embodiment of a flow control valve in accordance with the present invention; 
     FIG. 10A is a top plan view of a show in accordance with the present invention; 
     FIG. 11 is a cut-away top perspective view illustrating a fluid flow through the flow passage; 
     FIGS. 12 and 13 are side cut-away views illustrating the flow passage with the flow control valve in a seated position, stopping flow, and in an unseated position, permitting flow, respectively; 
     FIGS.  14 A and  14 B- 18 A and  18 B are side and top views of five alternate embodiments of a flap useful within the flow control valve, respectively of the present invention; 
     FIGS. 19A-19C are perspective and cross section views illustrating alternate seals for the flap; 
     FIGS. 20 and 21 are cross section views through the flow passage illustrating seated and unseated positions of an alternate embodiment of the flap in accordance with the present invention; 
     FIG. 22 is a cross section view taken through lines  22 — 22  of FIG. 20; 
     FIG. 23A is a top plan view of a sealing flange in accordance with the present invention; 
     FIGS. 23B and 23C are cross section views taken through  23 B— 23 B and  23 C— 23 C, respectively of FIG. 23A; 
     FIG. 24A is a top plan view of a sealing flange in accordance with the present invention; 
     FIGS. 24B and 24C are ross section views taken through  24 B— 24 B and  24 C— 24 C, respectively of FIG. 24A; 
     FIGS. 25A and 25B are cross section views taken through  25 — 25  of FIG. 25A for varying flow strengths; 
     FIG. 26 is a side elevation view illustrating an embodiment of the present invention in use in a swimming pool environment; 
     FIG. 27 is a side elevation view of a prior art swimming pool cleaner; 
     FIG. 28 is a partial cross section view of a flow control valve in accordance with the present invention illustrating operation within an alternate flow passage; 
     FIG. 29 is a forward top perspective view of an alternate embodiment according to the present invention; 
     FIG. 30 is a top rear perspective view of the embodiment of FIG. 29; 
     FIG. 31 is an exploded perspective view of the embodiment of FIG. 29; 
     FIG. 32 is a diagrammatic top view of a cleaning device in accordance with the present invention; 
     FIG. 33 is an exploded perspective view of an alternate embodiment of the present invention; 
     FIGS. 34A-34C are top views illustrating pawl engaging positions for a steering means in accordance with the present invention; 
     FIG. 34D is a side elevation view in cross section taken through the center thereof; 
     FIG. 35 is an exploded perspective view of an alternate embodiment of the present invention; 
     FIGS. 36 and 37 are partial top views of a ratchet and pawl embodiment in accordance with the present invention illustrating alternating biasing positions of the pawl; 
     FIG. 38 is an exploded cut-away view of a steering device in accordance with the present invention; 
     FIGS. 39 and 40 are top plan views of alternate ratchet and pawl embodiments in accordance with a steering means of the present invention; 
     FIG. 41 is a top plan view of a cooperating upper portion of the steering means operable with FIGS. 39 and 40; 
     FIG. 42 is a top plan view of another ratchet and pawl embodiment in accordance with a steering means of the present invention; 
     FIG. 43 is a top plan view of a cooperating upper portion of the steering means operable with FIG. 42; 
     FIG. 44 is a bottom view of an alternate embodiment of a shoe; and 
     FIG. 45 is an exploded perspective view of an alternate embodiment of the present invention illustrating the use of the show in FIG.  44 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiment of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     As initially described with reference to FIGS. 1-4, a swimming pool cleaning device, the pool cleaner  10 , for automatically cleaning a surface  12  submerged in liquid  14  comprises a forwardly inclined housing  100  having rigid walls  102 ,  104 ,  106 , and  108  forming a flow passage or chamber  110  extending therethrough from an inlet or entrance end  112  which in use is proximate the surface  12  to be cleaned, to an outlet or exit end  114  for connection to a flexible suction hose  16 . A flow control valve  200  is operable within the chamber  110 . Surface engaging means  300  comprises a shoe  302  carried by the housing  100  at the inlet  112  for engaging the surface  12  of a pool  18  to be cleaned. A flexible planar member, herein after referred to as a sealing flange  304  extends around the shoe  302 . When in use, the shoe  302  and sealing flange  304  engage the surface  12  to be cleaned. In an alternate embodiment of the present invention, steering means  400  is carried by the housing  100  and is operable therewith for rotating the housing  100  about the surface engaging means  300 , the shoe  302  and the sealing flange  304 , as will herein be described in further detail. 
     As described, the water interruption type pool cleaner  10  according to the invention includes the flow control valve  200  communicating with the housing  100  and the shoe  302  with which the cleaner  10  engages the surface  12  to be cleaned. In a second embodiment, and with reference to FIGS. 5-7, a foot  118  is attached to the housing  100 . A flange  116  is formed around the entrance end  112  of the housing  100  to facilitate attachment of the housing  100  to the foot  118 . 
     In the preferred embodiments, the sealing flange  304 , manufactured from flexible, resilient rubber-like material and incorporating a central opening  306  is attached to the shoe  302 . 
     As illustrated with reference again to FIG. 3, at least one inlet  120  to the housing  100  is in communication with the entrance end  112  and an exit end  114  of the suction chamber  110  to provide fluid flow  122  through the suction chamber  110  and into a flexible hose  16 . 
     As illustrated again with reference to FIGS. 1-7, the flexible hose  16  is connected to the cleaner  10  by means of a hose coupling  124  in communication with the exit end  114  of the housing  100  carrying the flow control valve  200 . In one preferred embodiment, to facilitate the turning of the cleaner  10  about an axis  126  extending through the hose coupling  124  and the flow control valve  200 , the coupling  124  is rotatable. As illustrated with reference again to FIGS. 2 and 3, the hose coupling  124  incorporates a nut  128  for attaching the coupling  124  to the exit end  114  of the housing  100 . Washers  130  reduce friction during rotation of the hose coupling  124  about the axis  126 . An annular recess  132  is formed between the nut  128  and the exit end  114  to facilitate attachment of devices such as a deflector to the cleaner or bumper  20 . 
     As illustrated with reference again to FIGS. 2,  3  and  7 , the shoe  302  comprises a resilient, flexible, rubber-like material and is attached to the foot  118  by engagement of a retaining lip  306  with a recess  308  located substantially around the perimeter of the foot  118  of the FIG. 7 embodiment or housing entrance end  112  in FIG.  3 . To provide fluid access to the suction chamber  110 , the foot  118  incorporates an opening  136  and the shoe  302  includes grooves  310  and an opening  312 . 
     In one preferred embodiment, as illustrated in FIG. 1, the sealing flange  304  does not rotate relative to foot  118  or shoe  302 . At least one locating tab  314  (illustrated with reference to FIG. 2) engages with a cooperating groove  310  or notch within recess  308  to orient the sealing flange  304  in a desired position as illustrated with reference again to FIG.  2 . The sealing flange  304  increases the suction grip of the shoe  302  to the surface  12 , assists with the cleaning action, helps the cleaner  10  move through the curved transitions between floors and walls of the pool  18 , and helps maintain adherence to the walls of a pool. Alternate means of attaching the shoe  302  or sealing flange  304  may be employed without departing from the functions of the foot  118 , shoe  302  and sealing flange  304 . 
     With reference again to FIGS. 5 and 6, the peripheral region of the sealing flange  304  in one embodiment has corrugations  316  such that it may be resiliently extended to more easily conform with the shape of the surface  12  to be cleaned and thereby more effectively maintain a suction grip against the surface  12 . 
     In the preferred embodiment as illustrated with reference again to FIG. 3, fluid flow  122 , illustrated with arrows, indicate the passageways for fluid flow  122  to enter suction chamber  110 . Fluid is drawn towards the foot  118  of the cleaner through at least one fluid intake aperture  318  in the sealing flange  304 , and from between the sealing flange  304  and the surface to be cleaned  12 . The liquid  14  then travels into the chamber  110  via the groove  310  and the opening  312  of the shoe  302 , and via the opening  136  through the foot  118 . The suction necessary to induce fluid flow  122  through the housing  100  helps to bias it toward and in contact with the surface  12  to be cleaned. Dirt particles and other debris such as leaves and twigs are thus carried by the fluid flow  122  through the cleaner  10  and into the attached flexible hose  16  towards the swimming pool&#39;s pump and filtration system. As illustrated again with reference to FIG. 3, at least two independent inlets  120  from the surface side an a rear wall inlet  138  to the chamber  110  are desirable to help avert possible damage to the cleaner and suction pump system in the event a single passageway become blocked. In particular, the multiple independent inlets  120 ,  138 , by way of example, will helo avoid personal injury should a single inlet be blocked by part of a person&#39;s body. 
     As illustrated with reference again to FIG. 3, a valve  140  is fitted to the cleaner  10  to regulate the flow of fluid through the inlet  138 . The valve  140  comprises a flexure or spring loaded member placed at least partially across the opening of inlet  138  so that the member will deflect in response to decreased pressure in the chamber  110  and thereby allow a greater volume of fluid to enter the chamber  110 . 
     In the preferred embodiment herein shown with reference to FIG. 3, the primary route of fluid flow  122  into the chamber  110  is via the fluid intake aperture  318  in the sealing flange  304  and thereafter through the openings  136 ,  312  at the inlet  120  in what will be referred to as the operating head  154 , which inlet is located between a lower surface of the sealing flange  304  and the surface  12  to be cleaned. The greater fluid flow  122  between the sealing flange  304  and the surface  12  to be cleaned improves the ability of the cleaner  10  to lift dirt and debris from the surface  12  to be cleaned. 
     Typically, apertures are found in the sealing flanges of many cleaners. However their function is not that of a primary route by which liquid  14  will enter the cleaner. Rather, their function is to sufficiently reduce the suction between the sealing flange and the surface to be cleaned to allow the cleaner to travel more effectively over the surface to be cleaned. The fluid intake aperture  318  within the sealing flange  304  of the present invention provides improved removal of debris and thus improved cleaning of the surface  12 . 
     By way of example, and with reference again to FIGS. 5-7, the primary inlet  120  for fluid flow  122  to enter into the entrance end  112  of housing  100  extends above an upper surface of the sealing flange  304 . The inlet  138  is also provided through the opening  136  in the foot  118 . 
     As illustrated with reference again to FIGS. 2,  4 , and  7 , to assist the foot  118  or show  302  of the cleaner  10  to make contact with the surface to be cleaned  12  in a desired attitude, e.g. where the plane formed by the underside of the foot  118  or shoe  302  is generally parallel with the plane formed by surface  12  in contact with the foot  118  or shoe  302 , a buoyancy member  22  comprises a float  24  hingedly attached to the top side or rear wall  104  of the cleaner  10 . As illustrated with reference to the embodiment of FIG. 5, a hinge  25  is attached to a top wall of the flow control valve  200 , preferably at the base of the rear wall  104 . As illustrated with reference to FIG. 1, a flexible stem  28  is used. As illustrated with reference again to FIG. 4, the buoyancy member  22  and its range of movement relative to its point of attachment to the cleaner  10 , assists the cleaner  10  to change its direction of travel away from the surface of the fluid. By way of example, when the cleaner  10  is against a verticcal wall  30  of the swimming pool  18 , the buoyancy member  22  urges the cleaner  10  to turn and travel towards the floor  32  of a swimming pool. With the buoyancy member  22  attached at the base of the rear wall  104 , as the cleaner  10  travels up a wall  30  of a swimming pool, the point of attachment will be urged toward that portion of the flow control valve  200  closest to the surface of the water. This action, as illustrated in FIG. 4 by the series of cleaner positions A through E and in turning the cleaner toward the floor  32 . The orientation of the buoyancy member  22  relative to the rest of the cleaner  10 , particularly when the cleaner itself is in a certain position relative to the surface  12  to be cleaned (e.g. against a wall  30 ), is adjusted through preferred geometric shapes  34  incorporated into the hinge  26  as shown in FIG.  8 . Interaction between the shape  34  and the stem  28  of the buoyancy member  22  controls the position of the buoyancy member  22 . 
     As illustrated with reference again to FIGS. 1 and 3, a weight  38  attached near the base of a front wall  102  of the flow control valve  200 , compliments the action of a buoyancy member  22  to turn the cleaner  10  traveling across a wall  30  of a swimming pool by urging the front wall  102  of the cleaner  10  to turn towards the floor  32  of the swimming pool. The weight  38  may be used without the buoyancy member  22 . 
     To further assist the cleaner in attaining a desired attitude, additional weights are attached to the housing of the cleaning apparatus. With reference again to FIGS. 5 and 6, one embodiment includes multiple weights  320  located on and around the peripheral region of the sealing flange  304 . Further, in lieu of or in addition to attached weights  320 , density increasing additives such as Barium Sulfate may be incorporated into the materials forming the cleaner  10 ; particularly the sealing flange  304 , shoe  302 , or foot  118 . 
     As earlier described and with reference again to FIG. 3, the suction chamber  110  is located between and communicates with the operating head  154  and the hose coupling  124  to provide a fluid passage through the cleaner  10 . In operation, the suction chamber  110  comprises the entrance end  112  in proximity to the submerged surface  12  to be cleaned and an exit end  114  connected to the hose coupling  124 . As illustrated with reference to FIGS. 1-13, the housing  100  and thus the suction chamber  110  can be described as having two sides  108  and  106  the front wall  102  and the rear wall  104 . The front wall  102  is generally lateral to the direction of travel indicated by arrous  40 . As illustrated again with reference to FIG. 3, the axis  126  of the passage through the suction chamber  110  is angled in a forward direction of travel  40  with respect to the surface  12  to be cleaned. Further, as illustated with reference to FIG. 9, the top/rear wall  104  is detachable. 
     As illustrated with reference again to FIG.  3  and FIGS. 9-13, a flap member  202  is mounted within the suction chamber  110  and includes at least one substantially rigid portion  204  joined to at least one flexible portion  206 . The flap member  202  comprises at least two ends  208 , at least two sides, a front face  210  and a rear face  212 . In a preferred embodiment, the flexible portion  206  comprises a single piece of resilient rubber-like material. Alternately, the flexible portion  206  may comprise multiple elements in a cooperative or hinged arrangement designed to perform the function of the flexible portion  206  as illustrated with reference to FIGS. 18A and 18B. 
     Each end  208  of the flap member  202  is pivotally mounted between two sides  108  and  106  of a suction chamber  110  about axes which are generally transverse to the flow of liquid through the suction chamber  110 . As illustrated with reference to FIG. 14B, the flap member  202  and the chamber  110  in which it is mounted are dimensioned such that at least two sides  210  of the flap member  202  remain in close communication with the sides  108  and  106  of the chamber  110 . As illustrated with reference again to FIGS. 3,  9 ,  11 , and  13  illustrate that the substantially rigid portion  204  of the flap member  202  is pivotally mounted closer to the exit end  114  of the chamber  110  and in spaced relation to both the front and rear walls  102  and  104 . The flexible portion  206  of the flap member  202  is mounted closer to the chamber entrance end  112  and attached to or in close proximity to the rear wall  104  of the chamber  110 . At least a portion of the flap member  202  must be capable of travel into a position of close proximity or contact with the front wall  102  of the chamber  110  to thereby substantially restrict flow there through or close a first passage  142  through the chamber  110 . 
     The ends  208  of the flap member  202  incorporate attachment means  228  which will facilitate simple attachment and detachment of the flap member  202  into the chamber  110 . FIGS. 9-13 illustrate the use of a C-clip to attach an end  208  of the rigid portion  204  to a shaft  31  fitted between the sides  108  and  106  of the chamber  110 . FIG. 9 illustrates the detachable rear wall (or lid)  104  and the flap member  202  in an exploded view detached from the chamber  110 . The detachable wall  104  includes a hook  144  at the entrance end  112  and a tongue/suction clip  146  at the exit end  114  for removably attaching the wall  104  to the chamber  110 . The tongue  146  is held in position by a portion of the nut  128 . Easy access is provided to the interior of the chamber  110  for removal of debris, replacement of the flap member  202 , and other maintenance tasks without the need for tools. Other means of attachment may be employed to attain the benefits of this invention. 
     In operation, and as illustrated with reference again to FIGS. 11 through 13, when the suction pump is activated, it causes fluid flow  122  through a first chamber  110  and primarily through a passage  142  between the front face  210  of the flap member  202  and the front wall  102  of the chamber. The fluid flow  122  in the first passage  142  will cause the flap member  202  to be drawn towards, and may cause a portion of the flap member  202  to make contact with the front wall  102  of the chamber  110 , as illustrated with reference to FIG.  12 . This action will substantially restrict or interrupt the fluid flow  122  through the passage  142  and cause a quantity of water to impact a front face of the flexible portion  206  of the flap member  202 . Restricted fluid flow  122  will occur between a side  210  of the flexible portion  206  and a side wall  108 ,  106  of the chamber  110  and then through a second passage  148  between a rear face  212  of the flap member  202  and a rear wall  104  of the chamber  110 . In this manner, the flexible portion  206  act as as a baffle to fluid flow  122  through the second passage  148 . Simultaneous with the interruption of fluid flow  122 , the action of the pump will cause a lower fluid pressure zone in the suction hose  16  and in the second passage  148  of the chamber downstream of a flexible portion  206  of the flap member  202 . The impact of fluid on a front -face of the flexible portion  206  and the lower pressure impinging upon a rear face  212  of a flexible portion  206  of the flap member  202 , each cause the flexible portion  206  to then deflect towards the lower pressure zone of second passage  148 . This action upon and of the flexible portion  206  will apply leverage to the rigid portion  204  and cause the rigid portion  204  and remainder of the flap member  202  to now pivot away from the front wall  102  of the chamber, thereby reopening the first passage  142  for fluid flow through the chamber  110 , as illustrated in FIG.  13 . This sequence of events is repeated for so long as the pump is in operation, and causes a regular interruption in fluid flow  122  through the suction chamber  110  and an automatic to and for reciprocating movement of the rigid, portion  204  of the flap member  202 . 
     The dimensions of the chamber  110 , rigid portion  204  and flexible portion  206  of the flap member  202  and the positions in which the flap member  202  is located within the chamber  110 , will in combination determine the rate and intensity of interruption of fluid flow  122  through the chamber  110 . It is anticipated that particular rates and intensities of interruption of fluid flow will be suited to particular tasks. 
     In general, the flow control valve  200  of the present invention is therefore well suited for incorporation into water inter, uption type swimming pool cleaners as a means foe providing a propulsive force. As disclosed in the prior art and by Chauvier in U.S. Pat. No. 4,023,227 and Raubenheimer in U.S. Pat. No. 3,803,658 in particular, sudden interruption of the fluid flow  122  through the chamber  110 , transfers the kinetic energy which had been developed by the fluid flow  122  as an impulsive force. In this case, the energy is transferred to the flap member  202  and thus cause the suction chamber  110 , which in a preferred embodiment is angled in a forward direction, to travel in that direction with respect to the surface  12  to be cleaned. The kinetic energy transferred to the angled suction chamber  110  will have a vertical component and a horizontal component, the horizontal component being in the direction of the arrow  40 , as illustrated by way of example in FIGS. 11-13. The interruption in fluid flow  122  also causes the flexible hose  16  to jerk. Further, the suction against the surface  12  to be cleaned is momentarily reduced each time that the fluid flow  122  is halted or restricted, thereby decreasing the frictional engagement of the foot  118 , shoe  302 , and sealing flange  304  against the surface  12 . This impulsive force, hose jerk and reduction in frictional engagement is sufficient to displace the cleaner  10  and travel across the surface  12  to be cleaned in the direction of the arrow  40 . 
     It should be noted that during operation of the flow control valve  200  one wall of the chamber  110  may be impacted more vigorously by a portion of the flap member  202  than the opposite chamber wall. As illustrated with reference again to FIG. 12, the front wall  102  of a preferred embodiment is impacted by the flap member  202  in the general region of the connection between a rigid portion  204  and a flexible portion  206 . The force of the latter impact is greater than the occurrence as described earlier with reference to FIG. 13, which reveals that when the flap member  202  moves towards the rear wall  104 , the surface area of the flexible portion  206  in close proximity or contact with the rear wall  104  will progressively increase which, together with resistance occurring upon flexing or hinging of the flexible portion  206 , will cushion the force applied against the rear wall. 
     In preferred embodiments, the flap member  202  is mounted within the chamber  110  in a manner such that the particular wall of the chamber  110  which, upon interruption of fluid flow  122  is impacted more forcefully by a portion of the flap member  202 , is the front wall  102 . This will enable the horizontal component of the force with which the flap member  202  impacts the front wall  102  to complement the horizontal component of the force derived from the interruption of fluid flow  122 , and thus enhance the forward displacement of the cleaner  10  across the surface  12 . 
     It has been found that the flow control valve  200  will operate and provide propulsive force even when fluid flow  122  through the chamber  110  is weak, for example, because of a low capacity pump, dirty filters, or other factors which are well known in the industry. The same flow control valve  200  has also been found to operate effectively at the other, higher, end of the fluid flow  9  spectrum usually experienced within the swimming pool industry. With lower fluid flow  122 , the rigid portion  204  will reciprocate to and fro through a lesser arc than it will with greater fluid flow. The greater the arc, the greater the opening to the primary passage  142  through the chamber  110  between the front wall  102  and the flap member  202 , consequently allowing a greater volume of fluid and debris to pass through the chamber. 
     As illustrated with reference again to FIGS. 11-13, the arc and rate of reciprocating movement of the rigid portion  204  may be governed by the placement of a limiting means or stop  214  between a wall  104 , of the chamber  110  or housing  100  and a face of the flap member  202 . A buffer  216  of rubber-like material is attached to the limiting means  214  or to the wall  104 ,  102  in an alternate arrangement. 
     In a preferred embodiment, the rigid portion  204  of the flap member  202  is manufactured using a substantially rigid plastic material. The flexible portion  206  is manufactured from a softer, flexible, resilient, plastic or rubber-like material. The hardness of the flexible material is typically between 40 and 90 using the Shore A Durometer scale. To help avoid tears, the flexible material may be reinforced with flexible ribs  218 , as illustrated with reference to FIGS. 17A and 17B, and/or fibers, cloth or other suitable means. 
     A fluid flow seal  220  is provided in the general area of the connection between the rigid  204  and flexible portions  206 , as illustrated in FIGS. 14A-18. Upon contact or proximity with the front wall  102  of the chamber  110 , the fluid flow seal  220  will substantially interrupt fluid flow  122  through the chamber  110 . Preferably, in order to buffer the impact of the seal against a wall  102 , the seal  220  may be manufactured from an impact absorbing material such as a resilient plastic or rubber-like material or incorporate an impact absorbing buffer  222  as shown, by way of example, in FIG.  18 A. As shown in FIG. 10 an impact absorbing buffer  216  may also be attached adjacent the front wall  102 . While the noise emitted by the subject invention is significantly less than that emitted by interruption-type pool cleaners typically found in the art, the use of the seal  220  made with an impact absorbing material or the inclusion of the buffers  216 ,  222  will further reduce the noise emitted by contact between the seal  220  and the front wall  102 . Buffers  216 ,  222  will also reduce the possibility of wear and damage to the cleaner  10  caused by repetitive impacts of the flap member  202  against a wall of the cleaner  10 . 
     In another preferred embodiment illustrated with reference to FIGS. 20 and 21, a recess  150  is provided in the front wall  102  of the chamber  110  to receive seal  220  when the flap member  202  is drawn towards the front wall  102 . The recess  150  is preferably oversized relative to the seal  220 . With this arrangement, it has been found that the seal  220  need not make contact with the front wall for fluid flow  122  to be sufficiently interrupted to provide the force for propelling the cleaner  10 . Yet further improvement in lower noise levels is achieved and the cleaner is less prone to trap and hold debris between the wall  102  and the seal  220 . 
     As earlier described, dirt particles and debris such as leaves and twigs will be drawn by the fluid flow  122  into and through the chamber  110  and flexible hose  16  towards the swimming pool filtration system. As illustrated with reference again to in FIGS. 14A,  14 B, and  20 , to optimize the function of the flow control valve  200 , the dimensions of the flap member  202  and the chamber are proportioned to minimize fluid flow  122  between a gap  226  formed between the edges  210  of the flap member  202  and the sides  108 ,  106  of the chamber  110 . A small gap  226  will minimize fluid flow  122  there through, but has the disadvantage that dirt and debris often become lodged in the gap  226 . To help prevent the entrapment of dirt or debris in the gap  226 , the sides  210  of the rigid portion  204  are dimensioned to be further away from the chamber sides  108 ,  106 , is attached to at least a portion of the rigid portion  204  to extend substantially across the gap  226 . The flexible edge seal  224  will flex to allow larger pieces of dirt or debris to pass through the gap  226 . 
     FIGS. 20 and 22 illustrate more than one seal  224  attached to a side  210  of the rigid portion  204  of the flap member  202 . This preferred embodiment provides a buffer of water sandwiched between the seals  224  and further reduces the possibility of entrapment of debris in gap  226  due to seepage of fluid flow between passageways  142  and  148 . 
     In the embodiment shown in FIGS. 9,  14 A, and  14 B, the edge seal  224  is formed as an integral part of the flexible portion  206  of the flap member  202 , and extends towards the end  208  of an attached, narrower, rigid portion  204 . Alternately, as illustrated in FIGS. 18A and 18B, the edge seal  224  may be a separate part attached to the flap member  202 , usually the rigid portion  204 . 
     FIGS. 15A,  15 B,  17 A, and  17 B illustrate embodiments of the flap members  202  where the rigid portion  204 , the flexible portion  206  and the edge seals  224  are integrally formed from the same rubber-like material, and where the flexible portion  206  and the edge seals  224  are thinner than the rigid portion  204 , thereby achieving the necessary rigidity and flexibility of the respective elements. FIGS. 17A and 17B illustrate the use of at least one rib  218  to achieve reinforcement or stiffening as may be required for desired operation of the flow control valve  200 . 
     At least one bushing  230  may be incorporated into an attachment means  228 , as in FIGS. 15A and 17A, for example. 
     In addition, by way of example, a sliding seal of the type disclosed by Sebor in U.S. Pat. No. 5,371,910 may be incorporated into the flap member  202 . Further with reference to FIGS. 19A and 19B, a seal  232  may be pivotally attached along the edge of at least one side edge  210  of the flap member  202  in an alternate embodiment of the present invention. FIG. 19C illustrates a flexible, resilient seal  234  attached at an angle to and outwardly extending from the edge of the flap member  202 . 
     As illustrated with reference again to FIGS. 20 and 21, a flap member  202 , in an alternate flap embodiment, includes multiple flexible portions  206   a ,  206   b  separately mounted closer to the chamber entrance end  112  and attached to or in close proximity to the rear wall  104  of the suction chamber  110 . This arrangement provides at least one buffer or water in a third or additional passageway  152  located between the passages  142  and  148 . This buffer of water in passageway  152  and the action of the additional flexible portion  206  significantly diminishes the propensity of water-borne debris to become lodged between a side  210  of a flexible portion  206   a ,  206   b  of the flap member  202  and a wall  108 ,  106  of the chamber  110  which would impair operation of the flap member  202 . 
     As illustrated in FIGS. 20 and 21, one flexible portion  206   a ,  206   b  will separate flow passages  142  and  152 , while another flexible portion  206   a  will separate flow passages  152  and  148 . This means that only one of the two flexible portions  206   b  is in direct contact with debris-laden fluid flow  122  entering passageway  142 . The sides of the flexible portions  206   a ,  206   b  are in close proximity with at least two walls  108 ,  106  of the chamber  110 , thereby enabling the flexible portions  206   a ,  206   b  to perform as baffles and restrict the flow of water from the volume of water in passageways  152  and the flow passages  142  and  148 . At least one aperture (inlet  138 ) in a section of the wall  104  of the chamber  110  is provided to allow, when the cleaner  10  is submerged, water to enter directly into passageway  152 , which will usually carry significantly less debris than water drawn into passageway  142  of the cleaner  10  via the operating head  154 . 
     During operation of the cleaner  10 , the pressure in passageway  148  will always be lower than in passageway  152 . Consequently, some of the water in the passageway  152  (which separates passages  142  and passageway  148 ) will seep between a side  109  of flexible portion  106  and the wall  108  or  106  of the chamber  110  into the passageway  148 . This occurence avoids seepage of debris-laden water around the side  209  of a flexible portion  206  from the passage  142  into passage  148 . When the passage  142  is open, as illustrated in FIG. 20, the pressure in that passage  142  and passage  148  will be lower than in passageway  152 . Consequently, water will seep from the passageway  152  into both passages  142  and  148 , thereby preventing debris from the debris-laden water entering passageway  142  from becoming lodged between the wall  108 ,  106  of the cleaner  10  and the side  209  of a flexible portion  206  of the flap member  202 . Further, as also depicted in FIG. 20, the flexible member  206  in contact with fluid flow  122  in the passage  142  will be bowed into the stream and present a convex shape less conductive to the entrapment of debris than the concave shape (earlier described with reference to FIG. 3) that would be presented to the fluid flow  122  by embodiments using a single flexible portion  206 . 
     Alternate embodiments for the sealing flange  304  suitable for the cleaner  10  of the present invention which does not employ positive steering means are illustrated with reference to FIGS. 23A-24C. Further, the sealing flanges  304  are intended for use with a cleaner embodiment such as that illustrated in FIG. 3 in which the primary route of fluid intake into the suction chamber  110  is via an intake aperture  318  in the sealing flange  304  The intake aperture  318  is improved by the incorporation of a resilient flap  322  which automatically adjust in response to the flow of fluid through the apertures  318 . A resilient flap  322  may be integrally formed with the sealing flange  304  and oriented such that when the cleaner  10  is not in operation, the resilient flap  322  extends into the intake aperture  318  to partially close such aperture  318 . To reduce the possibility that the flap  322  become snagged on an obstacle, the free end of the resilient flap  322  is directed rearwardly and to more than 90 degrees from the direction of travel  40  for the embodiments herein described. At least one rib  324  or other suitable stiffening means is integrally formed with the flap  322 . At least one rib  326  or other suitable stiffening means is integrally formed with the sealing flange  304  and located, for example where it reduces the flexibility and strengthens a portion of the sealing flange  304 . 
     By way of example, and as illustrated with reference to FIG. 23A, during operation of the cleaner, fluid flow  122  will travel across the upper surface of the sealing flange  304  and through the aperture  322  towards the foot  118  as earlier described. The greater the fluid flow  122  through the cleaner  10 , the greater the extent to which the resilient flap  322  will flex in response to that flow and thereby increase the cross-sectional area or opening of the aperture  318  to allow more fluid to pass there through as illustrated with reference to FIGS. 25A and 25B. In this manner, the adherence of the sealing flange  304  against the surface  12  to be cleaned will be controlled within a range conducive to optimum cleaner  10  performance. In circumstances where fluid flow  122  is at a lower end of that range usually provided by swimming pool suction pumps, due perhaps to a weaker pump or a dirty filtration system, the flap  322  will flex to a lesser degree and thereby make maximum use of the available suction and flow  122  to adhere the cleaner  10  properly to the surface  12 . Conversely, the flap  322  will flex more in circumstances where the suction and flow  122  is stronger and thereby avoid excessive adherence to the surface  12  to be cleaned which would otherwise be detrimental to cleaner operation and inhibit proper movement over the surface  12  to be cleaned. The flexing action is also useful should one intake aperture  318  become partially or fully blocked by, for example, a large leaf. In such a situation, the flap  322  will flex further in response to the greater suction caused by the blockage and, in so doing, may increase the opening sufficiently to allow the leaf to pass through. The flaps  322  will also flex in response to changes in the flow  122  through the groove  310  or grooves in the shoe  302  (described earlier with reference to FIG. 2) due, for example, to undulations in the floor of a swimming pool. 
     To help the cleaner  10  turn away from an obstacle or small radius transition in a swimming pool, for example a drain cover or where a step joins the floor, it is desirable that the peripheral portion  328  of the sealing flange  304  which typically engages the obstacle or small radius be able to flex to allow the flange  304  and its peripheral portion  328  to move over the obstacle or through the small radius. Since only a portion of the sealing flange will typically come into contact with the obstacle or radius, only a section of peripheral portion  328  of the sealing flange need flex at any one time. It is desirable that a section be capable of flexing independently of the remainder of the sealing flange  304 . FIGS. 23A and 24A illustrate flanges  304  which are segmented in a petal-like manner about their peripheries. Except at the rear of the sealing flange, it is preferred that the segmentation or slit not extend a distance greater than half of the distance between an outer extremity of the flange  304  and the opening control  306 . 
     It is also preferred that the sealing flange  304  be fixed in position by suitable means such as the locating tab  314 , earlier described. This will ensure that the leading portion  330  cannot rotate relative to the foot  118  of the cleaner  10  and will always point in the direction of travel  40 . 
     In operation, when the leading portion  330  of the sealing flange  304  engages a small radius such as at the base of a step, unless it travels across the radius, there is a chance that the cleaner  10  will not be able to move away from the step. If the leading portion  330  flexes through the radius as illustrated in FIG. 26, the cleaner  10  will travel at least part way up the step and then disengage itself and fall to one side or gradually turn to one side and move away from the area. 
     The deeper segmentation or slit at the rear of the sealing flange  304  enables two segments to splay apart when the cleaner travels through a small radius to allow the underside of the sealing flange  304  to maintain contact with the surface  12  to be cleaned. This action facilitates good frictional contact with the surface  12  and assists with continued forward propulsion of the cleaner  10 . If necessary, the cut or space between the segments may be substituted by a pleat  332 , as illustrated in FIG.  24 A. This configuration will allow the desired splaying between segments, but will limit the seepage of liquid through the space between segments. 
     The ability of the leading portion  330  of the sealing flange  304  to flex through a small radius or to pass over obstacles such as drain covers may be further improved by the incorporation of at least one lipped section  334  or at least one fin  336  protruding forward of the outer edge of a leading portion of the sealing flange  304 , as illustrated with reference to FIGS. 23 and 24. The shoe  302  may be integrally formed with the sealing flange  304 . 
     The ability of the cleaner  10  to move away from obstacles such as a step is further assisted by the employment of a bumper ring  20 , as illustrated with reference again to FIG.  1 . In a preferred embodiment, a conical shaped bumper ring  20  is removably and rotatably attached to the cleaner  10  by engagement with the annular recess  132  earlier described with reference to FIG.  3 . The bumper ring  20  may be removed without the use of tools by loosening the nut  128 . Given equal diameters of the rims in each case, the conical shape is an improvement over a planar ring because, when attached as shown in FIG. 26, the distance  44  of the lowermost portion of the rim  42  above the surface  12  to be cleaned is minimized. This enables the bumper ring  20  to be extended around the chamber  110  and thus hold the cleaner  10  away from obstacles. If appropriate for the conditions in a particular swimming pool, the bumper ring  20  may be inverted to increase the distance  44 . The alternate embodiments include the bumper ring  20  made from substantially rigid plastic material and from resilient rubber-like material. 
     The cleaner  10  described thus far need not employ positive steering means to navigate the surface  12  of the pool to be cleaned. The subject invention includes the ability to either incorporate such means into a flow interruption cleaner, or to provide means to simply attach positive steering to a cleaner  10 . 
     In order to accommodate steering means, particularly the means disclosed herein, a head  154  of the cleaner  10  is formed from two pieces  156  and  158 , each having flanges suited for interlocking connection, as shown in FIG.  31 . In a preferred embodiment, the upper piece  156  is formed as an integral part of the housing  100  forming the suction chamber  110 . The passageway  120  through the operating head  154  is in communication with the entrance end  112  and exit end  114  of a suction chamber  110  to draw fluid flow  122  from above the foot  118  of the cleaner  10  and into a flexible hose  16 , as earlier described. 
     As again illustrated with reference to FIGS. 29,  30 , and  31 , the operating head  154  and flow control valve  200  are rotatably connected to and supported by a foot  118  and a resilient shoe  302  with which the cleaner  10  engages the surface  12  to be cleaned. This will enable the operating head  154  and flow control valve  200  to rotate relative to the foot  118  and shoe  302  about an axis  412  substantially normal to the surface  12  to be cleaned and which extends through the center of the foot  118  and shoe  302 . 
     As illustrated again with reference to FIG. 31, a steering means to positively rotate the foot  118 , shoe  302  and sealing flange  304  may be accommodated in a position  202  between a lower portion of the operating head  158  and the foot  118  or shoe  302 . Embodiments of steering means are disclosed in detail later within this section. 
     FIG. 32 illustrates a cleaner  10  where the grip of the sealing flange  304 , foot  118  and shoe  302  against the surface  12  (the foot  118  and shoe  302  are hidden in this view by the sealing flange  304 ) minimizes or eliminates rotation of those components relative to the surface  12  to be cleaned. The same illustration shows the housing  100 , head  154  and flow control valve  200  rotatable about axis  412 . This embodiment does not include positive steering means. However, the ability of the head  154  simply to rotate relative to the surface engaging means is by itself sufficient to assist the cleaner  10  to avoid entrapment, for example, in corners of a swimming pool or by obstacles therein. 
     Flow interruption cleaners  10  having an inclined chamber  110  or housing  100  travel in the general direction  40  in which the hose coupling  124  points. As the cleaner  10  moves, it will push a length of the hose  16  ahead of itself. Consequently, as the length of the hose  16  is pushed towards, for example, the walls or a corner in a swimming pool, the hose  16  will bend and a force will be applied to the coupling  124  of the cleaner  10 . This will cause the coupling  124  and cleaner  10  to rotate through an arc relative to its foot  118 , other surface engaging means and surface  12  to be cleaned; thus a new course will be established. In cleaners which cannot rotate relative to their surface engaging means, the adherence of the cleaner to the surface  12  makes it more difficult for the hose to bend away early enough to avoid entrapment of the cleaner. The ability of a cleaner of this invention to rotate enables the hose  16  to bend away earlier and consequently the cleaner will follow the new direction indicated by the hose coupling  124 . 
     A free rotating arrangement as described in the previous paragraphs works best in smaller pools where the walls of the pool interact with and alter the orientation of the hose  16 . This interaction will help avoid a repetitive travel pattern which may otherwise be established by the cleaner  10 . Without frequent interference with the walls to randomly alter the position of the hose, the inherent resilience of the flexible hose  16  eventually directs the cleaner to a position where the hose is generally more relaxed, and the cleaner may adopt a repetitive pattern of travel (typically a figure eight) across the surface  12  to be cleaned. To overcome this limitation, a positive steering means  400  as herein described is provided for the cleaner  10  to positively rotate the cleaning head  154  relative to the cleaner&#39;s surface  12  engaging means, which in the above described embodiment is the foot  118 , the shoe  302  and the sealing flange  304 . The steering means  400  may rotate the cleaning head  154  continuously in one direction only, in one direction intermittently, in opposing directions without an intermittent period between directions, or in opposing directions with an intermittent period between directions. Further, the number of rotations or partial rotations before intermittent disengagement of the steering means in either direction may be varied. The speed of rotation in one or both directions is also controlled. 
     As shown in FIG.  33  and FIGS. 34A,  34 B,  34 C, and  34 D, an embodiment of a steering means suitable for incorporation into a cleaner  10  of the water interruption type having an inclined chamber  110 , may conveniently be incorporated within an annular chamber  404  formed by the mating of a lower portion of the operating head  158  and a cylindrical portion  408  of the foot  118 . As illustrated in FIG. 33, the lower portion of the operating head  158  may include means for easy attachment to another part  156  of the operating head. Other suitable receiving means for attaching positive steering components to the housing  100  of a cleaner  10  include the flange  116  as described earlier with reference to FIG.  6 . 
     The steering means  400  depicted in FIG.  33  and FIGS. 34A,  34 B,  34 C, and  34 D, will enable the housing  100  to rotate in opposing directions with an intermittent period between directions. At least one resiliently biased pawl  402  is mounted to the lower portion  156  of the operating head  154  within the annular chamber  404  and dimensioned such that a free end of the pawl  402  is capable of movement through a limited arc and may obliquely engage a raised portion  406  of the cylindrical wall  408  of the foot  118 , but will be spaced away from any portion which is not raised. A suitable means for resiliently biasing the pawl  402  is a tab  410  made from a flexible, resilient plastic material, the free end of such resilient tab  410  being capable of engagement with a portion of or part fixed to a lower portion  158  of the operating head  154 . The tab or tabs  410  may be positioned so that when the free end of the pawl  402  is not engaged with a raised portion  406  of the foot  118 , the tab or tabs  410  may position the pawl  402  so that it will approximately coincide with a radial extending from the center of the foot  118  towards the cylindrical wall  408 . The interior face of the cylindrical wall  408  may incorporate teeth or other means to engage with the free end of the pawl. 
     In operation, the pulsating fluid flow  122  through the chamber  110  causes the operating head  154 , housing  100  and flexible hose  16  to jerk or vibrate and, as previously described, resultant forces move the cleaner  10  in a forward direction. Additionally, this action will cause slight movement of the foot  118  relative to the lower portion  144  of the operating head  154 . If, as depicted in FIG. 34B, the pawl  402  is not engaged with a raised portion  406  of the cylindrical wall  408 , the cleaner  10  will move forward until such movement causes the position of the attached flexible hose to alter and thereby apply a force against the hose coupling  16  to rotate the head  154 . The incorporated lower portion  158  and attached pawls  402  moves toward the raised portion  406  of the cylindrical wall  408  of the foot. Continued application of the latter force rotates or deflects the pawl  402  and an attached flexible tab  410  until the pawl  402  engages the raised wall portion  406 , as is illustrated with reference to FIGS. 34A and 34B. Once so engaged with the raised wall portion  406 , the pawl  402  provides greater resistance to rotational movement in one direction than in the opposite direction. Consequently, the vibration of the cleaner  10  and a ratcheting action of at least one pawl  402  will cause rotation of the lower portion  158  of the operating head  154  relative to the cylindrical wall  408  of the foot  118 . This ratcheting action and rotation about axis  412  will continue until the end of the raised portion  406  of the cylindrical wall  408 . Those elements of the cleaner  10  fixed to the operating head  154  will also rotate relative to the foot  118  and the surface  12  to be cleaned. Since the cleaner  10  will move in the direction in which the hose coupling 16 points or is directed, if unobstructed, the cleaner will typically follow a curved course across the surface  12  to be cleaned. If the cleaner is lodged against a wall, a step or other obstacle in a swimming pool, when the pawl  402  is engaged, the cleaner will rotate in an opposition direction and. thus away from the obstacle and then proceed in a new curved forward direction until the pawl  402  disengages. This process will be repeated as the hose  15  interacts with the cleaner to re-engage the pawl  402  and thereby recommence the ratcheting rotational action. In this manner, the tendency of a swimming pool cleaner  10  to establish a repetitive action or to become trapped by an obstacle, will be reduced or eliminated. 
     If continuous rotation in one direction is desired, the raised portion  406  of the cylindrical wall  408  may be continued around the wall  408 , without any break. The pawls  402  can then be installed to provide rotation in a chosen clockwise or anti-clockwise direction. 
     It is expected that, without departing from the principles disclosed, modifications may be made to the embodiment of the above-described steering means. For example a pawl  402  maybe attached to a foot (instead of an operating head) and engage a wall or other suitable surface of the operating head (instead of the wall  408  or other inside portion of a foot) of the cleaner  10 . By way of further example, for frictional engagement with a pawl, a resilient insert is substituted for teeth of inner surface  412 . These examples are not intended to exhaust the possible alternate embodiments of this invention. 
     An alternate embodiment of steering means which will provide a cleaner  10  of the water interruption type having an inclined chamber  100  with steering in opposing directions without an intermittent period between directions is depicted in FIGS. 35-45. As with the previous embodiment, the steering means may conveniently be installed within the annular chamber  404  formed by the mating of a lower portion  158  of the operating head  154  and the cylindrical portion  408  of the foot  118 . Each end of at least one resilient means such as a flexure  418  is connected to a sleeve  416 , the resilient means and sleeves dimensioned to be rotatably attached to at least two shafts  414  fixed to the lower portion  158  of the operating head  154 . The distance between the axes of rotation extending through the center of two shafts  414  shall, prior to attachment of the steering means to said shafts  414 , be less than the distance between the center of the holes through two sleeves  416  interconnected by, for example, the flexure  418 . Thus when each sleeve  416  is slid over a shaft  414 , the flexure  418  must deform and thereby bias each sleeve  416  to a predetermined position relative to the shafts  414 . An engagement means such as a finger  420  communicates with at least one sleeve  416  and, upon rotation of the foot  118 , occasionally engages with means such as tab  422  attached with respect to the foot  118  or driven by the rotation of the foot  118 . With reference to FIGS. 36 and 37, when the finger  420  and flexures  418  are positioned in a first position as shown in FIG. 36, the application towards the right of increasing force against the left hand side of the finger  420 , will, upon application of sufficient force, overcome the force stored in the deformed flexures  418 , whereupon the flexures will rapidly deform and take up a second position as depicted in FIG.  37 . Upon such deformation of the flexure  48  into the second position, the sleeves  416  will rotate through an arc to a second predetermined sleeve position. Attached to at least one sleeve  416  are two pawls  424  and  426  dimensioned so that when the sleeves  416  and flexure  418  are in a first position, a first paw will engage an inner toothed surface  412  of the cylindrical wall  408  of the foot  118 , and when the sleeves  416  and flexure  418  are in a second position, the second pawl will engage such surface  412 . To facilitate frictional engagement, the face of a pawl and/or the inner surface  412  of the cylindrical wall  408  incorporate teeth  430  or comprise at least one resilient layer attached to the cylindrical wall  408 . 
     In operation, the pulsating fluid flow  122  through the chamber  110  causes the operating head  154 , chamber  110  and flexible hose  16  to jerk or vibrate and, as previously described, resultant forces move the cleaner  10  in a forward direction. Additionally, this action will cause slight movement of the foot  11  relative to the lower portion of the operating head  158 . In this embodiment, at least one pawl  424  will be engaged with the surface  412  and will provide greater resistance to rotational movement of the lower portion of the operating head  158  relative to the foot  118  in one direction than in the opposite direction. By means of a ratcheting action, the pawl  424  will cause the lower portion  158  of the operating head  154  to rotate relative to the foot  118 . This ratcheting action and rotation will continue in a first direction until a tab  422  driven by the rotation of the foot  118  engages a finger  420  and applies sufficient force thereto to cause the flexure  418  to deform to a second position and cause the first pawl  424  to disengage the surface  412  and a second pawl  426  to engage the inner surface  12 . The ratcheting action and second pawl  426  will cause rotation in a second direction, opposite to the first direction. As earlier described, the tendency of a swimming pool cleaner  10  to establish a repetitive action or to become trapped by an obstacle, is greatly reduced or eliminated. 
     In a preferred embodiment as illustrated in FIG. 38, the inside surface  412  of the cylindrical wall  408  is formed using a resilient, rubber-like layer  428  suitable for frictional engagement with pawls  424  and  426 . The pawls  424  and  426  are camming pawls. When a free end of a camming pawl, say  424 , is in friction a engagement with the resilient friction surface  412 , vibration of the cleaner and a ratcheting action of the pawl  424  will result in rotation of the operating head  154  relative to the foot  118  in a first direction. Use of the resilient layer  428  on the surface  412  of the wall  408  or on the free end of a pawl  424  or  426  has an advantage over the use of teeth on either of those surfaces. The advantage is that the action of the pawl  424  or  426  is not limited by the size of any teeth and the need for the free end of a pawl  424  or  426  to consistently traverse any such teeth in order to provide an efficient ratcheting action. While the increments may become small if the hose, for example, applies significant torque in a direction opposite to that in which the steering means is rotating, a resilient friction layer  428  has been found to be effective in enabling the rotation to continue until the steering means s itches rotation to a second direction. 
     The number of rotations that the lower portion  158  of the operating head  154  makes relative to the foot  118  is determined by the placement of tab or tabs  422  driven by the rotation of the foot. FIG. 38 illustrates a means employing at least one ring  800 A,  800 B, and additional tabs  422 B, C, D, whereby tab  422 D ill engage finger  420  after more than one rotation in either direction. More than one rotation in each direction is particularly useful for consistent disengagement of a cleaner  10  from obstacles in a swimming pool. 
     FIG. 40 illustrates that multiple linked flexure  418  and more than one engagement finger may be employed in this embodiment of steering means. 
     In yet another embodiment, as illustrated with reference to FIG. 42, linkage arms  430  are used to link more than one pair of pawls  424  and  426 . This arrangement is useful to assure that both flexures  418  and both pairs of pawls reliably orient themselves in a first and then a second position as required for operation of the invention. As will be obvious to those reasonably skilled in the art, a similar arrangement employing only a single flexure in combination with a linkage arrangement  430  will also satisfy the requirements and will fall within the scope of the invention. 
     FIGS. 44 and 45 illustrate out-of-round she  302  and sealing flanges  304  either of which, upon engagement with a wall or obstacle, will reduce rotation of the shoe  302 , sealing flange  304  and other surface engaging means relative to the surface  12  to be cleaned. This feature improves the rotation of the housing  100  and hose connector  16  relative to the surface to be cleaned. Once the housing  100  and hose connector have been driven through an arc by the steering means, the hose connector will point in a direction free of the obstruction, and the cleaner will move away from the obstacle. Resilient members  432  may be attached or integrally formed with the shoe  302 . Such resilient members  432  enhance the grip of the shoe against a wall or obstacle. Other improvements which may be made to a shoe  302  are to increase its height and deepen the grooves  310  for increased fluid flow through a passageway formed between the shoe  302  and the surface  12  to be cleaned. Also, to reduce slippage of surface engaging means of the flange  12  against the surface  12  to be cleaned, sealing flange stiffeners  338  are attached to or integrally formed with the sealing flange  304 . 
     A reading by those skilled in the art will brig to mind various changes without departing from the spirit and scope of the invention. 
     To this point, the embodiments of cleaners  10  incorporating the flow control valve  200  have all described at least the chamber  110  and consequently a significant dimension of the cleaner  10  to be forwardly inclined with respect to the surface  12  to be cleaned. FIGS. 1 through 6 illustrate such embodiments. The flow control valve  200  is, as a source of vibration or oscillatory motion, also suited for incorporation in cleaners in which the suction chamber  110  is substantially normal to the surface  12  to be cleaned. As illustrated with reference to FIG. 28, useful in the swimming pool cleaner described in U.S. Pat. No. 5,404,607 to Sebor. FIG. 28 illustrates a flow control valve of this invention incorporated into the suction chamber  110  of a cleaner  10 A here the suction chamber  110 A is not inclined. A preferred embodiment of a cleaner described in the &#39;607 patent further requires that a shaft disposed in the chamber be driven and engage a means to translate the reciprocating angular movement of the shaft into one directional angular movement of a driven gear. The flow control valve  200  of the present invention will provide a reciprocating angular movement to a sleeve  102  or drive shaft  234 , which movement may be translated and coupled with other mechanisms necessary to perform a number functions for a pool cleaning device, including steering functions. 
     Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. The specific embodiment shown in the accompanying drawings and described herein is offered by way of illustration only Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and alternate embodiments are intended to be included within the scope of the appended claims.

Summary:
A swimming pool cleaning device for automatically cleaning a submerged surface includes a forwardly inclined housing forming a flow passage between a surface to be cleaned and a suction hose. A flow control valve is operable within the flow passage and includes a flap pivotable from a seated position against the front wall of the housing for blocking flow through the passage to an unseated position in a spaced relation to the forward wall, permitting. A shoe is carried at an inlet to the flow passage and a flexible planar disc extends around the shoe for engaging the surface to be cleaned. A groove within the shoe bottom surface forms a channel with the surface for passage of debris and fluid flow through the channel. The flexible planar member includes slits extending from the peripheral edge inward toward the central opening to form a pedal-like segmented flange for splaying of each segment in response to travel of the cleaner over an irregularly contoured surface and facilitate an effective frictional contact with the surface. A steering mechanism is operable between the housing and shoe for rotating the housing about the shoe and planar member, and includes a ratchet and pawl operable between upper and lower steering members for providing free rotation in one direction in response to a pulsating fluid flow through the flow passage, while biasing against rotation in an opposing direction.