DE69307358T2 - Underwater suction device with its own drive and cleaning process - Google Patents

Description

The invention relates generally to suction cleaners for use on surfaces submerged in a liquid. The suction cleaner is attached to a flexible hose and a pump as its suction source. The invention relates to a device for automatically cleaning the submerged surfaces of a swimming pool and the like.

Self-propelled vacuum cleaners are commonly used to clean the submerged areas of a pool, and particularly a swimming pool, that has various finishes and profile shapes. Various techniques have been used in the mechanisms that power these self-propelled cleaners. Three of the more common mechanisms use either a shut-off valve, a turbine drive or drive wheels. In some cases, combinations of these mechanisms are used.

U.S. Patent 4,536,908, issued to Johann N. Raubenheimer on August 27, 1985, discloses a suction cleaner for a swimming pool that is supported by a trailer or tractor assembly with inclined support legs. The trailer assembly is mechanically moved back and forth by means of a turbine through which water is drawn by suction to cause the cleaner to move. To change the direction of travel of the cleaner, a second turbine drives a hose connection on the top of the cleaner in opposite directions with long dwell times in between. In other words, the device is continuously driven in forward or deviating directions.

A turbine-driven pool cleaner is also known from US patent 4,939,806, issued to Carl F. Supra on July 10, 1990. In this Supra device, a cleaner having a head is mounted on wheels. There is a suction channel and a propeller driven by the turbine that drives the head forward. To change the direction of movement of the head, a rudder is used that is pivoted via a gear train driven by the turbine.

In U.S. Patent 5,099,535, issued March 31, 1992 to Daniel J.V.D. Chauvier, - Underwater Surface Cleaner -, a turbine and wheel device is disclosed. In this device by Chauvier, an underwater surface cleaner has a body defining a suction channel and a pressure channel. The suction channel extends between an inlet and an outlet in the body and is connectable to the inlet of a filtration system by a flexible hose. A second hose connects the inlet on the device to an outlet of the system. Water flowing under pressure to the inlet drives a turbine which in turn drives rear wheels to move the device over the surface while sucking particulate matter or the like through the suction channel and out through the hose attached to the filtration system. The suction hose and the return hose are flexible hoses, as commonly used in pool cleaning systems.

In US Patent 4,208,752, issued to Helmut, J. Hofmann on June 24, 1980, a device for cleaning swimming pools with a step-by-step movement over the pool walls has a balanced working head with an inlet and an outlet, the outlet being pivotally connected to a longitudinally extending, elastic and flexible suction hose The inlet axis is inclined at an angle to that of the outlet. A channel extends through the head from inlet to outlet and an oscillator valve in the head is used to open and close the channel alternately. A baffle plate is arranged in the head between the inlet and the valve to form a restricted suction connection between the inlet and outlet around the valve when the channel is closed. The water flow causes the valve to oscillate between its two end positions. In one position the full and direct flow is through the opening and channel to the outlet. In the other position of the valve there is a maximum reduction in the flow of liquid through the head. This results in an intermittent interruption of the flow through the head as the valve oscillates between its end positions. This in turn causes pulsation which results in longitudinal contractions and relaxations in the longitudinally extending elastic suction pipe from the head to the outlet from the swimming pool to its filter unit. As a result of these contractions and relaxations and a simultaneous decrease and increase in the force applied to hold the cleaning head disc against the surface to be cleaned, a gradual movement of the head over the surface to be cleaned occurs.

U.S. Patent 4,807,318, issued to Dieter HF Kallenbach on February 28, 1989, - Suction-Actuated Cleaner - discloses an automatic pool cleaner that also operates by interrupting an induced water flow through the cleaner. The interruption in the water flow drawn through the pool cleaner is used to create a propulsive force to cause the cleaner to move over underwater pool surfaces. The interruption control is provided by a tubular, axially elastic diaphragm. which has one end closed and normally keeps closed a channel leading from the head of the pool cleaner to the usual form of flexible hose connecting the pool cleaner to the filtration unit. The flow of water through the pool cleaner causes a suction effect in a passage which is greater than that in a connection. The result is that a spring and the diaphragm force the passage to close. The intermittent interruption of the flow through the passage and hose and the simultaneous release of the force holding the cleaner and disc against the underwater surface causes the cleaner to move progressively over the surface to be cleaned.

In addition to the mechanism used to move the cleaner along the submerged surface to be cleaned, various accessories have been added to these devices to provide some control over the cleaning pattern and to control the cleaner when it encounters obstacles such as sudden surface changes and when it exits the fluid in which it is submerged and is intended to operate. The prior art relating to such submersible pool cleaners has been generally amenable to these various methods of automatically propelling the cleaner over the surfaces to be cleaned, each of which presents problems inherent in its design.

In the cleaning devices that use shut-off valves, the valve inlet is prone to clogging with large foreign bodies. To correct this condition, the cleaning device must be removed from the tank and disassembled for cleaning. The diaphragms used in these units have a tendency to break and require replacement. The large current reduction required to produce the step-by-step motion of the cleaner results in large changes in head on the suction pump, which places additional wear on that pump and its motor. Cleaners using turbine systems depend on the high speed motion of the turbine, the large number of bearings, and the variety of parts required to convert the high speed rotation into the relatively slow cleaning motion. In addition, the many bearing surfaces perform poorly when they have been operating in the sand which wears away the bearing parts. Cleaners that rely on wheels for transportation have problems climbing vertical walls of common swimming pools. The wheels slip when attempting to maneuver on the vertical wall, and under certain conditions slip when climbing from the deep end to the shallow end of the pool.

Many of the devices in use have a tendency to follow a set pattern once they are put into operation. This pattern, which often corresponds to the figure eight, therefore tends to exclude certain areas in favor of others that see the cleaner more often than necessary. Finally, the use of new plastics and fiberglass pool surfaces has given rise to the additional requirement for these devices to be maneuverable over slippery surfaces, which was not previously the case. The aim of the prior art is to establish that the device covering the desired submerged areas is capable of handling vertical walls, avoiding obstacles, avoiding climbing out of the submerged liquid where the intake of air causes damage and interrupts operation, placing a minimum of excess demand on the suction pump and motor system, and having as few failure-prone parts as possible such as to have possible.

DE-A-2 620 119 discloses a submersible suction cleaner with an oscillating element which serves to change the flow path through the device (preamble of claims 1 and 20).

EP-A-0 476 413 discloses an immersion vacuum cleaner using an oscillating element acting on its shoe in conjunction with angled brushes to impart a self-propelling motion. EP-A-0 476 413 is only relevant under Article 54(3) EPC regarding novelty in respect of the designated states DE, ES, FR and GB.

The aspects of the invention are set out in the appended claims.

One embodiment of the invention provides a self-propelled suction cleaner used in conjunction with a swimming pool suction pump and motor to remove dirt and debris from submerged surfaces of the pool. The system and method are also intended for use in other environments. The cleaner is connected to a coupling located on the top of a housing. The coupling is connected to the suction pump and motor using a flexible elongated hose. The cleaner housing has a suction chamber located within the housing. The suction chamber has an inlet end near the submerged surface to be cleaned and an outlet end connected to the coupling.

An oscillator is pivotally mounted in the suction chamber. As the water flows past the oscillator, a reciprocating motion results. The shape and size of the chamber between the oscillator and the coupling cause abrupt changes in the water flow and a continuous vibratory motion of the housing. The housing has peripheral walls. A shoe is formed around the periphery of the housing, which is suitable for engagement with the submerged surface to be cleaned. The shoe has three or more rows of tread elements angled in a forward direction with respect to the surface. The element angles and the vibratory motion of the housing cause the cleaner to move forward in a random pattern over the submerged surfaces, including a vertical surface, of the pool. In preferred embodiments, the surface engaging elements of the shoe extend on elongated tracks parallel to each other and perpendicular to the forward movement or may consist of a plurality of finger elements each arranged at an angle. In the preferred embodiment, the angles range from an angle which is more vertical in front of the housing shoe than behind it, with each track or element changing its angle progressively away from vertical as the elements pass from front to back.

By making the coupling rotatable, the cleaner can be made to randomly turn at set time intervals and enable it to free itself from pool obstructions. Means are provided for converting a counter-angular or reciprocating motion of the oscillator into an angular motion in one direction for the purposes of driving a shaft by engaging a ratchet. A drive gear substantially secured to the shaft engages a gear train.

The gear train engages the rotary clutch at specified intervals to produce rotation of the clutch at those specified intervals.

A means for limiting the height of the cleaner as it climbs a vertical wall of the pool has a limiting member secured to the housing and extending forwardly and outwardly therefrom. The member is sized and arranged such that when the upper end of the member breaks the water surface, gravity reduces any forward momentum of the housing and that its extended member acting as a torque arm has the effect of turning the cleaner back toward the water. By securing a hollow limiting member to the housing or by having openings in the hollow member communicating with openings in the housing so that water can fill the hollow member, the relative weight of the cleaner while submerged in the water is reduced, whereby the reciprocating motion of the cleaner is more effective in propelling the cleaner. The increased weight of the restrictor as it rises out of the water turns the cleaner back into the water due to the water contained in the restrictor.

The suction chamber at the chamber inlet end near the surface to be cleaned can become clogged with foreign matter. To prevent foreign matter from reducing the flow to a point that creates excessive suction, which damages the pump and motor, the suction chamber has a pressure relief valve. The pressure relief valve has a bypass opening in a housing wall that communicates with the suction chamber. A bypass plug is fitted over the bypass opening and can be moved between a closed position, in which water is prevented from flowing through the opening, and an open position. is movable in which the water flows from the bypass opening into the coupling onto the pump. The bypass closure is held closed by the use of a spring preloading device in the preferred embodiment. The opening in the housing wall consists of a plurality of slots in the preferred embodiment.

A gap is provided between the oscillator side walls and the suction chamber walls. This gap should be as small as possible for optimal flow through the chamber and to achieve optimal oscillator forces. As the gap size increases, flow through the gap inhibits oscillator vibration. Sand and debris can fill the gap and interfere with oscillator movement. The preferred embodiment includes an oscillator having an elongated groove along the edge of the oscillator and a sealing strip extending into the groove and extendable across the gap.

The state of the art includes a variety of suction cleaners. An example of the more common suction cleaners using vibrator valves, turbine assemblies and wheels was discussed in the description introduction. Each of these suction cleaners has specific problems. Foreign objects clog cleaners using vibrator valves and diaphragms to the point where the diaphragm ruptures and must be replaced. At a minimum, the cleaner requires disassembly before cleaning and reassembly. Turbine mechanisms have high-speed movement. The high-speed movement requires bearing surfaces and complex speed-reducing parts. Sand and gravel, such as those found in common swimming pools, wear the bearing surfaces quickly, and the sand wears down these parts altogether. Wheeled cleaners have problems climbing the walls.

The wheels skid when they encounter the vertical walls and steep slopes from the deep end to the shallow end of typical pools. Existing cleaners tend to skid on the fiberglass and vinyl surfaces currently used. Most cleaners require smooth transition areas and can get stuck on a step, for example. Many cleaners create a pattern in the pool that is not efficient for cleaning all surfaces. Cleaners equipped with a shut-off valve use a stepping motion to propel the cleaner forward, which intermittently and dramatically interrupts the flow and induces high suction and pressure, placing excessive stress on the pump and motor.

Embodiments of the present invention avoid the problems inherent in the described designs and provide a self-propelled suction cleaner which utilizes a continuous suction flow through the cleaner and uses this continuous flow to provide the vibratory motion needed to propel the cleaner forward. The embodiments have a means for limiting the height of the cleaner above the water line of the pool, thus preventing the pump from sucking in unwanted air. The random pattern of the cleaner as it advances across the pool surface is enhanced by a turning means which prevents the cleaner from catching on obstacles such as steps or abrupt changes in the surface of the pool. Should foreign objects clog the cleaner suction chamber, a pressure relief valve is activated, thus eliminating excessive stress on the pump and motor.

During operation of the preferred embodiment, nominal pressures ranging from 10 kPa were measured at a location near the weir in a pool cleaning system. Open hose pressures were measured at approximately 8 kPa. In contrast, devices using a power interruption to induce movement produce nominal pressures ranging from 22 kPa to 30 kPa measured at the same weir location. (1 kPa is equal to 1000 Pascal units, a metric pressure measure. One pound per square inch is equal to 6.89 kPa units.)

A preferred embodiment of the invention, which includes alternative elements, is described, for example, with reference to the accompanying drawings, in which

Fig. 1 is a side view of the preferred embodiment of the self-propelled underwater cleaner,

Fig. 2 is a bottom view of the cleaner housing shown with the shoe removed,

Fig. 3 is a partially sectioned side view of the suction chamber showing the arrangement of the oscillator and buffer configurations,

Fig. 4 is a view of the shoe from below with elongated running elements and edging elements shown,

Fig. 5 is a perspective view of an oscillator used in the preferred embodiment,

Fig. 5a (side view) and Fig. 5b (bottom view) show alternative designs of the oscillator and the sealing arrangement,

Fig. 6 is a partially cutaway view of a portion of the oscillator showing the sealing arrangement,

Fig. 7 shows an alternative embodiment of a split oscillator in a perspective view,

Fig. 8 is a bottom view of another embodiment using movable suction chamber side walls,

Fig. 9 is a perspective view of the cleaner from the rear showing the rear enclosure and pressure relief valve openings,

Fig. 10 is a bottom view of a shoe tread having finger elements, with edging elements shown,

Fig. 11 is a partially sectioned view of the cleaner housing showing an embodiment of a pressure relief valve using leaf springs,

Fig. 12 is a coil spring version of the pressure relief valve in a partial sectional view,

Fig. 13 is a partial sectional view of the pressure relief valve of the preferred embodiment,

Fig. 14 is a perspective view of the drive mechanism showing the locking wedge and ratchet assemblies,

Fig. 15 is a partial cross-sectional view of the drive mechanism with the locking wedges shown in the locked condition,

Fig. 16 is a second partial cross-sectional view of the drive mechanism showing the sprags in the released state,

Fig. 17 is a partial sectional view of the drive mechanism associated with the oscillator,

Fig. 18 is a partial sectional view of the gear train and the rotary clutch engagement,

Fig. 19 is a partial top view showing the interval drive teeth of the interval drive gear engaging the translative intermediate toothing which engages the clutch gear,

Fig. 20 is a partial end view of the interval drive gear engaging with a reduction intermediate gear,

Fig. 21 is a partial view showing the driven gear meshing with the reduction gears with respect to the oscillator,

Fig. 22 is a partial top view showing the rotary clutch with the clutch gear engaging the interval gear via the intermediate translational gearing,

Fig. 23 is a perspective exploded view of the friction tooth assembly,

Fig. 24 is a partial perspective view of the ratchet mechanism used to engage the drum, and

Fig. 25 is a partial cross-sectional view of the friction drive mechanism associated with the oscillator.

The preferred embodiment of the invention, a submerged self-propelled vacuum cleaner 10, describes in particular a swimming pool cleaner 10 which utilizes the flow of water through a cleaner housing 12. This embodiment is described generally in Figs. 1 to 4 of the accompanying drawings. The housing 12 contains a suction chamber 14 having a mouthpiece 16 disposed at an inlet end 18 into which water flows. The chamber outlet end 24 communicates with a coupling 26 disposed on the top of the housing 12. In the preferred embodiment, the coupling is rotatable. The propulsion mechanism for the cleaner 10 includes an oscillator 20 pivotally mounted on side walls 22 of the chamber 14. The oscillator 20 is disposed in the flow path of water through the suction chamber 14. The flow is caused by connecting the suction chamber 14 to a motorized filter pump by a suitable flexible hose, as is conventional in swimming pool cleaning. The hose is connected to the coupling 26. The oscillator 20 is shaped so that the flow passing therebefore causes it to reciprocate about a pivot point and strike the front wall 28 and the rear wall 30 of the chamber so as to produce a vibratory motion of the chamber 14 and the housing 12 of which the chamber 14 is an integral part. This vibratory motion acting on the housing 12 causes a shoe 32 attached to the periphery 34 of the housing 12 and in contact with the submerged pool surface 36 to vibrate. The shoe 32 has three or more rows of tread elements 38 which contact the submerged surface 36 at an angle 40. This angle 40 is sized to drive the housing 12 in a forward direction and thus propel the cleaner 10 over the submerged pool surface 36.

The cleaner 10 propelled in this forward direction 42 (shown in Fig. 1) would typically follow a somewhat random path determined by the pool surface contours peculiar to a particular pool. To improve path randomness and to avoid the development of a path pattern, the preferred embodiment of this invention has a turning mechanism 200 utilizing a rotary coupling 26 and means for converting the vibratory motion to rotary motion to guide the cleaner 10 around at least a 90° turn at intervals. Such a turn during the random path ensures that the path does not form a pattern, typically a figure eight pattern in many pools. In addition, should the cleaner 10 encounter an obstacle such as a step, as is commonly found in swimming pools, the turn of 90º or more allows the cleaner to be maneuvered away from the step.

The cleaner 10 climbs up the submerged vertical wall of the pool and reaches the surface of the water. As can be seen from Fig. 1 and Fig. 9, the preferred embodiment has a height limiter 100 which turns the cleaner back towards the water if it tries to climb out. This limiter 100 enables a flow of water to always be present in the suction chamber 14 and prevents the harmful suction of air by the pump.

The suction chamber 14 is designed to receive sand and also larger foreign objects, such as leaves commonly found in swimming pools, without clogging. However, should the suction chamber become clogged and the pressure in the chamber 14 seriously increase, a pressure relief valve 300 is part of the preferred embodiment. The embodiment is described below with additional details of the elements that make up the preferred embodiment of the cleaner 10, as well as alternative embodiments for some of these elements.

The oscillator 20 and the suction chamber 14 can be described in more detail as follows:

In order for the oscillator 20 to operate efficiently, it must be positioned in a suction chamber 14 so that the oscillator 20 swings in close proximity to the side walls 23 of the chamber 14. This is necessary so that the mass of the flow moves past the oscillator 20 along the surfaces designed to produce the reciprocating motion of the oscillator.

The suction chamber arranged in the housing 12 has side walls 22, a front wall 28 and a rear wall 30, the front and rear walls being formed by the housing 12 in the preferred embodiment, as shown in Fig. 2 and Fig. 3.

The oscillator 20 (shown in Fig. 3 and Fig. 5) is hinged in the suction chamber to a hinge pin 92 which extends through an insert 44 on the oscillator and is mounted on the side walls 22.

As shown in Fig. 3, the liquid stream 90 entering the suction chamber 14 through the mouthpiece 16 of the housing encounters the oscillator 20 and flows around the edges 46, causing the oscillator 20 to oscillate back and forth on its hinge pin 92 and strike the front wall 28 and rear wall 30 of the chamber. Buffer formations 70 are disposed between the edges 46 of the oscillator 20 and the chamber walls. In addition, the flow has an abrupt change at the top of the chamber as the stream 90 approaches the oscillator. 20 past the chamber outlet and to the clutch 26.

It will be noted that the operating efficiency of the oscillator 20 depends on the magnitude of the current across the oscillator edges 46. As this current dissipates around the oscillator side edges 48 and 50 between the latter and the chamber side walls 22, the magnitude of the current past the oscillator edge 46 decreases with a consequent decrease in the efficiency of the oscillator's propulsion action.

In order to prevent such a loss of flow energy, the arrangement can be such that the oscillator 20 is arranged just between the chamber side walls 22, so that only a small current can be dissipated. In this case, however, fine gravel sucked into the suction chamber 14 can settle between the oscillator 20 and the side walls 22, causing a loss of efficiency of the oscillator 20 due to friction or the oscillator 20 can even become stuck.

According to the present embodiment, the oscillator 20 (shown in Fig. 5) and the suction chamber 14 are designed so that the edges 48 and 50 are appropriately spaced from the side walls 22 of the suction chamber 14 so that pea gravel can easily pass therethrough. Retractable elongated seals 54 are provided at each edge of the oscillator 20 to seal the gap 52 between the edges 48 and 50 of the oscillator 20 and the side walls 22 of the suction chamber (shown in Fig. 6).

Elongated seals 54 (Figs. 5 and 6) are arranged in a slot 56 in the respective edges 48 and 50 of the oscillator 20, the width of the strips not being greater than the depth of the slots 56.

In an alternative embodiment (shown in Figs. 5a and 5b) of the oscillator 20, seals 54a are contoured for the oscillator 20 with their ends 54b seated in slots 56a located on the oscillator edges 46 (as shown in Figs. 5a and 5b). Slide rods 54c are attached to the seals 54a which provide a means for sliding the seals 54a back and forth to displace peat during a cleaning process of the cleaner 10. When the suction chamber 14 is coupled to a filter pump and water is caused to flow around the oscillator 20 in the suction chamber 14, the seals 54 are pulled outwardly from the slots 56 into sealing engagement with the chamber side walls 22 of the suction chamber 14. During normal operation of the oscillator 20, the engagement between the elongated seals 54 and the chamber side walls 22 results in minimal friction and minor detriment to the efficiency of the oscillator 20. When the pea gravel finds its way between a seal 54 and the side walls 22, the seal 54 is simply forced into the slot 56, allowing the pea gravel to easily pass through the suction chamber 14 into the pool's filter system.

According to an alternative arrangement shown in Fig. 7, the oscillator 20 is divided into two sections 20a and 20b. The oscillator sections 20a and 20b have a groove 60. A tongue 58 is slidable into and out of the groove 60.

When fine gravel finds its way between the seal faces 48 and 50 and the chamber side walls 22, the oscillator sections 20a and 20b are simply forced back along the tongue 58 and into the groove 60 of the oscillator sections 20a and 20b, thereby creating a gap between the elongated seals 54 and the chamber side walls 22 of the suction chamber 14. is opened so that the fine gravel can easily pass through the suction chamber 14 into the filter system of the swimming pool.

In Fig. 8, a second alternative is provided in the form of a suction chamber 14 having side walls 62 and 64 arranged so that end sections 62a and 62b and 64a and 64b are slidable into and out of guide tracks 66a, 66b and 68a, 68b, respectively.

Under normal conditions, the side walls 62 and 64 are drawn against the oscillator 20 by the suction effect created in the suction chamber 14. However, should pea gravel enter between the oscillator 20 and the walls 62 and 64, the latter are simply drawn back into the guide tracks 66a, 66b and 68a, 68b, allowing the pea gravel to pass through the suction chamber into the pool's filter system.

Due to the strength and frequency of the impact of the oscillator against the front wall 28 and rear wall 30 of the chamber, buffer formations 70 are defined on the chamber wall 28 and 30 at the joints between the impacting oscillator edge 46 and the chamber wall. In the preferred embodiment, these buffer formations 70 are rubber-like cushions. These buffer formations thus protect the housing 12 and the cleaner 20 as a whole from damage that may result from the action of the oscillator.

The shoe arrangement 32 is described in more detail below.

As disclosed above and with reference to Fig. 4, the shoe 32 has three or more rows of tread elements 38. The tread elements 38 may be in the form of elongated rails 32, as shown in the preferred embodiment of Fig. 4, wherein the rail elements 72 are spaced apart and generally parallel to one another and the elongated element is perpendicular to the forward direction 42 of cleaner movement. The elements 72 are angled forwardly with respect to the submerged surface. In the preferred embodiment shown in Fig. 1, the elements 72 form an acute angle 40 with respect to a perpendicular to the shoe. As the elements progress from the front of the housing 74 to the rear 76, the angle 40 increases progressively for each respective element 72. The first rows of elements 72 at the front 74 are shorter than at the middle or rear to better accommodate climbing a steep vertical pool wall.

In addition to this climbing feature in the preferred embodiment, a coupling bellows 78 is attached to the coupling 26. This bellows 78 provides additional flexibility to the end of the flexible hose and allows for improved performance of work on the steep vertical pool wall. Fig. 1 shows this configuration of the coupling bellows 78.

In an alternative arrangement, the shoe 32 has three or more rows of tread elements 38 consisting of a plurality of finger elements 80 provided in a matrix arrangement as described with reference to Fig. 10. The matrix consists of parallel rows of finger elements 80 spaced in the same manner as the parallel rows of rail elements 72. Each row of finger elements 80 is angularly arranged and shaped like the rail elements 72 with a tread element angle 40 and, with progression of increasing angles, in front to back movement as previously described.

The outside portion of the shoe 32 that makes contact with the surface has an outside dimension determined by the housing perimeter 34 and an inside dimension to provide sufficient contact with the surface to be cleaned and an opening for access to the nozzle 16. The tread members 38, whether finger members 80 or rail members 72, form a shoe that is removably secured to the housing perimeter and partially extends around the nozzle 16 of the suction chamber 14. A flap 82 (shown in Fig. 4 and Fig. 9) is pivotally attached to the housing perimeter just behind the suction chamber rear wall 30. In an alternative embodiment, the flap is made as an integral part of the shoe, with the shoe then extending completely around the nozzle 16. The flap 82 provides a means of adjusting and controlling the flow by swinging open and closed during suction changes. In addition to the flap 82, an inner skirt 84 (see Fig. 4 and Fig. 10) and an outer skirt 86 are arranged near the periphery which prevent the free flow of water through the shoe elements, thereby causing an increase in suction. The skirts can be made as part of the shoe element or as part of the housing. In the preferred embodiment, both types are provided. An inner skirt section 88 consists of an extension of the chamber front wall. The remainder of the inner skirt 84 is part of the shoe, as is the outer skirt 86. The height of the two skirts is slightly shorter than the tread elements 38 to allow the elements 38 to flex during their vibratory and propulsive movement.

The edgings project downwards as described. In a preferred embodiment, the outer edging 86 is designed so that the tread elements 38 at the front of the housing 12 are almost completely exposed, but only slightly protrude beyond the bezel at the rear of the housing, as shown in Fig. 9.

The inner skirt portion 84 may be integrally molded with the housing 12 and disposed adjacent and inside the elements and extends from one side of the suction chamber 14 to the other along its front. Both the outer skirt 84 and the inner skirt 88 are also disposed laterally of the elements so that the elements can flex under the vibratory action of the oscillator 20.

It will be seen that the flow of water into the suction chamber 14 is directed around the free edges of the inner casing 84 and the outer casing 86 to provide sufficient suction through the suction chamber 14 onto a submerged surface engaged by the cleaner 10.

It is also a feature of the embodiment that the leading edge of the elongated shape of the shoe is a straight edge, substantially perpendicular to the direction of travel of the cleaner 10. The trailing edge is preferably also a straight edge, as shown in Fig. 2. It has been found that the straight leading and trailing edges of the shoe 32 and the tread elements 38 improve the mobility and climbing ability of the cleaner.

As already discussed, it has been found that the difference in angle of the elements (shown in Fig. 1) in the front and rear edges increases the climbing ability of a cleaning device on an upwardly curved radius surface, the climbing ability of the suction cleaner being increased by the straight front and rear edges of the enclosing formation is further increased.

The height limiter 100 can be described as follows:

The housing 12 has a limiting element 110 which in the preferred embodiment comprises a tube in the shape of an inverted U which is connected at its ends to the housing 12 towards its sides so that the open ends 112 of the tube are in communication with the housing 12.

As shown in Fig. 1 and Fig. 2, the element 110 extends upwardly and forwardly with respect to the housing 12, and when the latter is submerged in a swimming pool, the element 110 fills with water.

As the cleaner 10 advances toward the side of the pool, the cleaner rises until the upper end of the element 110 breaks through the water surface while the suction chamber 14 of the housing 12 is just below the water surface. As the element 110 emerges from the water surface, it undergoes an apparent increase in weight. The upward and forward extension of the element 110 and its dimensions are designed so that the increase in weight counterbalances the forward momentum of the head when the latter is just below the surface. In this way, the element 110 acts as a height limiting device preventing the suction chamber 14 from breaking through the surface of the water and sucking in air, which would impair the operation of the pump.

By adding a flexible portion to the extension member 110 near the housing 12, the vibratory motion of the housing 12 causes the extended restrictor member 110 flexes. This flexing reduces the resistance created by the movement of member 110 through the water, allowing freer vibration and thus efficient operation of cleaner 10. In the preferred embodiment, bellows couplings 114 are attached to restrictor member 110. The flexible nature of bellows 114 provides a sufficiently reducing lever arm and results in smoother forward movement of cleaner 10.

The turning mechanism 200 can be further described as follows:

In order to illustrate the cleaning system more clearly, an embodiment of a drive mechanism is described below with reference to Figs. 14 to 18 of the accompanying drawings.

The drive mechanism 210 shown in Figures 14 through 17 is used in the underwater cleaner 10 to convert the reciprocating angular movement 212 of a drive shaft 214 into a directional angular movement 216 of a driven gear 218. The driven gear 218 can perform a number of functions for the pool cleaner. It is particularly contemplated that it drives a gear train mechanism 220 for a pool cleaner through a number of reduction gears 222, such as those shown in Figure 18, which are used to rotate a rotatable clutch gear 254 and thus the clutch 26.

The drive mechanism has a peripheral ring 226 with teeth 228 which are fixed in or form part of a drum 230 formed at the end of the driven gear 218. The teeth are periodically engaged with a plurality of claw or sprag elements 232, pivotally mounted in pockets 234 formed in a collar formation 236 at the end of the drive shaft 214. The collar 236 of the drive shaft 214 and the sprag members 232 are positioned in the drum 230 of the driven gear 218 so as to enable the sprag members 232 to periodically engage the inner teeth 228.

The pockets 234 which pivotally support the sprag members 232 form opposed stop surfaces 234a, 234b which act to limit the pivotal movement of the sprag members 232 between a first extreme position (shown in Fig. 15) in which the sprag members 232 are arranged substantially radially for engagement with the teeth 228 and a second extreme position (shown in Fig. 16) in which the sprag members 232 are angularly disposed with respect to the radial and disengaged from the teeth 228.

It is a feature of the embodiment that the sprag elements 232 operate in a liquid medium such as water, preferably the same liquid in which the surface to be cleaned is submerged, which medium imparts a high degree of inertia to the sprag elements 232. The free ends 232a of the sprag elements 232 thus tend to remain stationary during angular movement of the drive shaft 214 in one direction or the other. Thus, when the locking wedge elements 232 are in the first extreme position and are radially aligned (Fig. 15), a rotational movement of the drive shaft 214, for example in a counterclockwise direction, causes the locking wedge elements 232 to move to the second extreme position (Fig. 16) and to remain in such a position during the first counterclockwise rotation of the drive shaft 214. When the shaft 214 reverses its direction of rotation in a clockwise direction, they similarly align the Locking wedge elements 232 immediately to the first extreme position in which they are radially aligned and engage with the teeth 228 of the driven gear 218.

To enable rotational movement of the driven gear 218 into directional movement, the embodiment further includes a claw 240 and a pinion gear assembly with circumferential ratchet teeth 242 formed on the outer periphery of the drum 230 and engaged by the claw 240 mounted independently of the drum 230.

The driven gear 218 rotates during movement of the cleaner 10 via the prescribed conversion of the reciprocating angular movement 212 into a directional angular movement or rotation. This rotating driven gear 218 can be coupled to a variety of drive mechanisms including a mechanism for lifting the suction chamber to break the suction, causing the cleaner to fall from a vertical wall, as an alternative embodiment for the height limiter 100 discussed earlier.

In the preferred embodiment, the transmission gear 218 is used in conjunction with a gear train 220 (as described with reference to Figures 18-22) that meshes with a clutch gear 254 that meshes with the clutch 26. The driven gear 218 meshes with a first gear 244 and a series of reduction gears 222 for meshing with an interval drive gear 248. The interval drive gear 248 has a set of interval teeth 250 that mesh with the clutch gear 254 through an intermediate translation gear 252. The interval drive gear 248 has enough teeth 250 arranged on it to allow the clutch 26 to rotate through at least a 90° range.

In an alternative embodiment of the drive mechanism (Fig. 23 to Fig. 25), a friction drive is adapted to convert the oscillating angular movement of a drive shaft 214 into a periodic angular movement in one direction of a driven gear 218. The driven gear 218 can then drive other gears as previously described to bring about the rotation of the cleaner 10.

The friction drive shown in Fig. 23 to 25 has a first friction surface 260 formed by a disk element 262 to which the drive shaft 214 is attached or with which it is formed in one piece. The friction disk 262 is pressed into contact with a second friction surface 264 formed by a second disk 266 by means of a compression spring 268. The second friction disk 266 in turn has a driven gear 218 associated with it. The second friction disk 266 is attached to a drum formation 236 to which the driven gear 218 is attached or with which it is formed in one piece, so that the rotational movement of the friction disk 266 causes a rotational movement of the gear 218.

In an alternative arrangement (not shown), the driven gear 218 is attached to a friction disk, as shown at 262, which is urged into frictional engagement with a friction surface formed by the inner blind surface 268 of the drum formation 236, with the drive shaft 214 attached directly to the drum 236 or to the friction disk 262.

In the embodiment shown, the friction disk 262 is brought into frictional engagement with the friction surfaces 264 by means of a compression spring 268 which ends in washers 270 and 272.

In order to limit the movement of the driven gear 218 to a directional movement as shown by the arrow 216, an arrangement with a claw 240 and a ratchet wheel 242 is also provided, the teeth of the ratchet wheel 242 being formed on the outer surface of the drum 236. According to Fig. 24, the claw 240 in the form of an elastic leaf spring is provided so as to engage the teeth 242 to prevent reverse rotation of the drum 236 and thus the driven shaft 218.

The pressure relief valve 300 is further described below:

The housing 12 has a suction chamber 14 with side walls 22 and end walls 28 and 30, which are formed by the housing itself.

The coupling 26 is provided on the housing 12 for a suction hose (not shown) which is used to connect the suction head to the filter pump of the swimming pool. Connecting the housing 12 and the chamber 14 to the filter pump results in a flow into the suction chamber 14 via the mouthpiece 16. The flow first strikes one edge 46 and then the other edge 46 of the oscillator 20, causing the latter to oscillate back and forth.

It will be appreciated that if large objects such as leaves, twigs, and the like, accumulate in narrowed areas of the flow path past the oscillator 20, the flow path could be blocked. If a release or bypass valve is not provided, the motor driving the pump will be damaged.

In the present embodiment, the housing 12 has bypass openings 310 in the suction chamber 14 at its upper end in near the coupling 26 for the suction hoses. These bypass openings 310 are closed by a bypass closure 312 which is hinged to a hinge pin 314 in the suction chamber 14. Leaf springs 316 are fastened with their ends 316a to the housing 12 in the suction chamber 14 and with their opposite ends 316b to the bypass closure 312. The leaf springs 316 thereby bias the closure 312 into a position in which the bypass openings 310 are closed. Fig. 11 shows this embodiment.

During normal operation of the suction cleaning device, the restricted passages in the oscillator 20 arrangement are unobstructed and the springs 316 exert sufficient pressure to hold the shutter 312 in a closed position. However, if the inlet to the suction chamber should become obstructed with leaves or other foreign objects, the pressure in the suction chamber 14 will drop abnormally due to the action of the filter pump, thereby forcing the shutter 312 away from the bypass openings 310 against the biasing action of the springs 316. This causes water to flow into the suction chamber 14 and the suction hose via the bypass openings 310 until the blockage in the suction chamber is removed. In this way, the bypass openings 310 act as a pressure relief valve 300, ensuring that the pump does not run dry and the motor is not endangered. It will be seen that positioning the bypass openings 310 downstream of the oscillator but away from the pool system weir makes it unlikely that the openings 310 will become blocked. It also eliminates air induction at the weir when the water level is low.

The strength of the springs 316 is additionally balanced to ensure that water is drawn into a controlled path via the bypass valve, which provides an additional means for regulating the speed of the oscillator and thus forms the suction at the suction chamber mouthpiece 16.

Similarly (shown in Fig. 12), coil springs 320 may be used to hold the bypass closure 312 against the bypass openings 310. In a third and preferred embodiment, the bypass openings 310 are closed using a flexible plate 322 that is biased against the openings 310 by securing one end of the plate 322a to the chamber wall adjacent the openings as shown in Fig. 13.

It will be apparent to those skilled in the art that the specific embodiments described above may be modified in various ways without departing from the scope of the invention as defined by the appended claims.

Claims (21)

1. Self-propelled submersible vacuum cleaner, which - a housing (12) with a coupling (26) for a connection to a flexible hose connected to a cleaning system pump with motor, - a suction chamber (14) arranged in the housing, which has an inlet (18) in the immediate vicinity of a submerged surface and an outlet (24) connected to the coupling, - an oscillator (20) which is pivotably arranged in the suction chamber, and - has a sliding shoe (32) suitable for engagement with the submerged surface, which is formed substantially around a circumference of the housing and extends as a whole laterally over the housing to the inlet, characterized, - that the oscillator (20) performs a continuous reciprocating vibration movement when liquid flows across the oscillator, a gap (52) being present between an edge of the oscillator (20) and a wall of the chamber, and - that the sliding shoe has three or more rows of tread elements (38) which are inclined so that they engage the submerged surface at an angle (40) inclined forwards from the perpendicular to the submerged surface. 2. A cleaner according to claim 1, wherein the tread elements are elongated, the longitudinal direction of each tread element extending across the housing. 3. A cleaner according to any one of claims 1 and 2, wherein the oscillator further comprises a sealing device (54) slidably mounted on the edge of the oscillator so as to extend across the gap, but is retractable away from the chamber wall under the action of a foreign body which becomes lodged between the sealing device and the chamber wall to thereby open the gap and thereby allow the foreign bodies to pass through. 4. A cleaner according to claim 3, wherein the oscillator has an elongated groove (56) along its edge and the sealing means comprises a sealing band (54) extending into the groove and stretchable across the gap. 5. Cleaner according to one of claims 1 and 2, in which the oscillator consists of at least two parts (20a, 20b) connected by a tongue (58) and a groove (60), the tongue and the groove being aligned with each other. for connection during operation of the oscillator. 6. A cleaner according to any preceding claim, wherein the tread elements are arranged substantially parallel to one another and at least partially enclose the inlet to the suction chamber, and wherein the cleaner further comprises a flap (82) removably attached to the periphery of the housing and engaging a rear edge of the suction chamber inlet in the immediate vicinity of the surface, wherein the flap and the running surface elements together substantially enclose the suction chamber inlet. 7. A cleaner according to any preceding claim, further comprising at least one buffer structure (70) against which the oscillator strikes during its oscillatory movement, the or each buffer structure transmitting oscillator impact forces to the cleaner housing. 8. A cleaner according to any preceding claim, further comprising an outer enclosure (86) formed by front, rear and opposite side walls of the housing, all of the housing walls forming the outer enclosure extending at least partially around the suction chamber and sized across the front wall to leave the tread elements substantially clear along the front, and an inner enclosure (84) extending around at least a portion of the suction chamber. 9. A cleaner according to any preceding claim, wherein the coupling is a rotary coupling connected to a flexible hose attached to a motorized cleaning system pump, the cleaner further comprising means (200) for rotating the cleaner about an axis of the coupling. 10. Cleaner according to claim 9, in which the rotating devices - a drive shaft (214) which can be operated alternately, - a collar (136) attached to the drive shaft, from which wedge elements (232) extend radially, - a ring (226) surrounding the collar, the inside teeth (228) for engagement with the wedge elements, which are sized and selected to be effective in a dense medium which serves to hold the wedge elements stationary with respect to a drive shaft which is rotatably coupled to the ring of teeth and whose angular rotation causes the wedge elements to move to a first extreme position when the shaft is rotated in one direction and to a second extreme position when the shaft is rotated in the opposite direction, whereby engagement with the teeth of the ring occurs during such movement, - means (240, 242) for limiting the rotation of the ring in one direction, - a drive gear (218) attached to the ring, - a gear train (220) having a first gear (244) rotatably engaged with the drive gear and a reduction gear (252) rotatably engaged with a clutch gear (254), the clutch gear being fixed to the rotatable clutch, and - an intermediate gear (240) having teeth (250) for engagement with the clutch gear, which are spaced at defined intervals so as to produce rotation of the clutch at the defined intervals. 11. A cleaner according to any preceding claim, further comprising means (100) for limiting the height of the cleaner suction chamber in a liquid having the submerged surface. 12. Cleaner according to claim 11, wherein the height limiting device comprises a limiting element (110) which extends forward and outward from the cleaner housing and is so dimensioned and arranged that when an upper end of the element pierces the liquid surface as the suction head climbs upward on a submerged substantially vertical surface, gravity reduces any forward momentum of the suction cleaner and the extended element has the effect of rotating the cleaner back towards the liquid. 13. A cleaner according to claim 12, wherein the height limiting element comprises a substantially hollow element (110) connected at one end to the housing, which has openings (112) communicating with the end of the hollow element so that the liquid filling the housing can also fill the hollow limiting element. 14. The cleaner of claim 13, further comprising a flexible portion (114) between the hollow member and the housing. 15. A cleaner according to any preceding claim, further comprising means (300) for limiting suction in the chamber, the means providing a pressure release for the system pump and motor which creates the suction. 16. A cleaner according to claim 15, wherein the height limiting means comprises means for displacing the cleaner shoe when it climbs up a submerged vertical surface by interrupting the suction of the suction chamber and allowing the cleaner to withdraw from the vertical wall. 17. Cleaner according to claim 15 or 16, in which the chamber suction limiting device - a bypass opening (310) in one of the housing walls communicating with the suction chamber, - a bypass closure (312, 322) fitted over the bypass opening and movable between a closed position preventing fluid from flowing through the bypass opening and an open position allowing fluid to flow out of the bypass opening and into the coupling, and - a device (316, 320, 322, 322a) for biasing the closure into the closed position, the biasing device being selected such that it is overcome by a predetermined high suction pressure through the coupler. 18. A cleaner according to claim 17, wherein the biasing means is a spring (316, 320) and the opening is formed by a plurality of holes (310) in the peripheral wall. 19. A cleaner according to any preceding claim, wherein the coupling includes a flexible element (18). 20. A method for cleaning a surface submerged in a liquid, the method comprising the steps of: - Providing a cleaner (10) with a suction chamber (14) having chamber walls (22, 28, 30) arranged in a housing (12), an inlet end (18) near the surface and an outlet end (24) which engages a rotatable coupling (26), - Connecting the rotating coupling to a flexible hose attached to a suction pump and motor system is, - moving an oscillator (20) pivotably mounted on an axis on the chamber walls back and forth about the axis so that liquid can be sucked into the chamber around one side and then around the other side of the oscillator, and - Attaching a sliding shoe (32) which is formed at least partially around a periphery of the housing and is suitable for engagement with the submerged surface, characterized, - that the sliding shoe has three or more rows of tread elements (38) arranged at an angle in the forward direction with respect to the surface, - that the chamber walls are designed in such a way that abrupt changes in the flow of liquid into the chamber are generated, which cause a vibrating movement of the cleaner, - that a flap (82) is attached which is removably seated on the periphery of the housing and is connected to a rear edge of the suction chamber inlet end, the flap and the running surface elements substantially enclosing the suction chamber inlet end, - Converting the back and forth movement of the oscillator into a rotary movement, - rotating the cleaner about an axis of the rotary coupling at selected intervals by using a gear train (220) connecting the rotary coupling to a drive shaft (214) rotatably attached to the oscillator, - limiting the cleaner height during climbing up a submerged vertical wall by attaching an extension element (100) to the housing, which enables the cleaner to rotate back to liquid when the cleaner climbs over a liquid surface, and - Limiting suction in the suction chamber by providing a bypass flow path around the suction chamber inlet end. 21. The method of claim 20, wherein the step of converting the reciprocating motion of the oscillator into a rotary motion further comprises - allowing the drive shaft to operate in an alternating manner, - securing a collar (236) to the drive shaft, having spline elements (232) extending radially therefrom, - arranging a ring (226) around the collar and the wedge elements, the ring having internal teeth (228) engageable with the wedges and a pawl outer surface (242), - providing a claw (240) attached to the housing, - limiting the rotation of the ring in one direction using the annular pawl surface and the claw, - attaching a drive gear (218) to the ring and - driving the gear train (220) which engages the drive gear (218) and a clutch gear (254) which is attached to the rotatable clutch, - wherein an intermediate gear (248) in the gear train engages at predetermined intervals.