Patent Description:
This relates to the field of swimming pool cleaners and, more particularly, automatic pool cleaners.

Automatic pool cleaners are designed to move along submerged pool surfaces and remove debris similar to a vacuum cleaner. They may be powered by electricity, positive pressure, or suction. Unfortunately, electric and pressure-powered pool cleaners can be very expensive. Further, many pressure-powered pool cleaner require a second pump to be used to create sufficient pressure.

Suction pool cleaners have several advantages over electric and pressure-powered pool cleaners. Suction pool cleaners are usually much more simple to construct, making them less expensive to manufacture and easier to replace worn parts. And, because suction pool cleaners are powered by the same pump used to operate the pool, they do not require additional pool equipment.

<CIT> (MAYTRONICS LTD) discloses a pool cleaner comprising a drive mechanism operable to drive the pool cleaner along a submerged surface of a pool in a forward direction; a housing carried by the drive mechanism, the housing having a bottom with an inlet port that receives debris removed from the submerged surface; and an outlet port in fluid communication with the inlet port.

A problem with suction pool cleaners is that they can get stuck on submerged obstacles such as drains and can also lose suction and cause the pool pump to air lock if they climb above the waterline of the pool.

According to the present invention, a pool cleaner includes a drive mechanism operable to drive the pool cleaner along a submerged surface of a pool in a forward direction. A housing carried by the drive mechanism has a bottom with an inlet port that receives debris removed from the submerged surface. An outlet port is in fluid communication with the inlet port. A plenum is on the bottom for enhancing suction around the inlet port. A vent mechanism defining at least one opening through the housing is forward the outlet port. A water port defining at least one opening on the bottom is in fluid communication with the vent mechanism. When the forward end of the pool cleaner extends above the waterline of the pool, water flows through the vent mechanism and the water port over the plenum so as to prevent loss of suction at the inlet port.

The pool cleaner may include one or more of any of the following features.

The vent mechanism and water port may be positioned in such a way that the waterline passes through the vent mechanism and water port simultaneously when a forward end of the pool cleaner extends above a waterline of the pool.

The water port may be positioned forward the inlet port and directly under the vent mechanism.

The plenum may include a recessed area around the inlet port and the water port may be positioned forward the recessed area.

The plenum may include a forward retractable member extending laterally across the bottom and forward the inlet port and the water port may be positioned directly vertical above the forward retractable member.

A drive mechanism may be operable to drive the pool cleaner along the submerged surface of a pool in the forward direction and a turning direction using a drive train having a pinion gear that operably mates with a wheel gear on a wheel of the drive mechanism. A cam is operable with the pinion gear and includes a radially enlarged and a radially constricted section arranged about a circumference of the cam. A drive shaft contactor is connected to the pinion gear and cam in such a way that the pool cleaner changes between moving in the forward direction and turning direction when the drive shaft contactor contacts the radially enlarged or the radially constricted section of the cam. The drive shaft contactor is spring biased against the cam about a rotational axis passing through the drive shaft contactor.

The pool cleaner may further include a forward retractable member extending laterally across the bottom and forward the inlet port, a rear retractable member extending laterally across the bottom and rearward the inlet port, and a protruding member extending downwardly from a plenum top surface and longitudinally between the forward retractable member and rear retractable member. When the pool cleaner drives over a submerged obstacle, the protruding member contacts the submerged obstacle and tilts the pool cleaner to prevent the pool cleaner from becoming stuck on the submerged obstacle.

This disclosure describes exemplary embodiments, but not all possible embodiments of a pool cleaner within the scope of the appended claims. Where a particular feature is disclosed in the context of a particular example, that feature can also be used, to the extent possible, in combination with and/or in the context of other examples, within the scope of the appended claims. Within the scope of the appended claims, a pool cleaner and methods may be embodied in many different forms and should not be construed as limited to only the examples described here.

Referring initially to <FIG>, certain features of an example of the pool cleaner <NUM> are described. The pool cleaner <NUM> includes a housing <NUM> having a forward end <NUM>, a rear end <NUM>, a top <NUM>, a bottom <NUM>, a first side <NUM>, and a second side <NUM>. Extending from the top <NUM> is an outlet port <NUM> defined by an outlet port housing <NUM>. The outlet port <NUM> is in fluid communication with an inlet port <NUM> defined on the bottom <NUM> of the housing <NUM>.

When suction is applied at the outlet port <NUM> via a suction hose (not shown), water and debris from submerged pool surfaces are drawn through the inlet port <NUM> in order to clean the submerged surfaces. As will be explained later, such suction is also used to propel the pool cleaner <NUM> in a forward direction F and a turning direction T.

The first side <NUM> and second side <NUM> include a respect drive mechanism <NUM> in mechanical communication with the suction. The drive mechanism <NUM> drives the pool cleaner <NUM> in various directions across the pool surface, including across the pool bottom and up the pool side walls.

In the example shown in the drawings, the drive mechanism is a track drive mechanism <NUM> and includes a track <NUM> wrapped around a first wheel <NUM> and a second wheel <NUM>. The first wheel <NUM> is positioned rearward of the second wheel <NUM>. In the example shown, a diameter D1 of the first wheel <NUM> is enlarged relative to a diameter D2 of the second wheel <NUM>. In other examples of the pool cleaner <NUM>, the drive mechanism may employ wheels without tracks.

The bottom <NUM> of the pool cleaner <NUM> defines a plenum <NUM> that creates an area of suction around the inlet port <NUM>. The plenum <NUM> includes a forward vertical wall <NUM> and a rear vertical wall <NUM> extending downwardly from a top plenum wall <NUM> and laterally between opposed plenum sidewalls <NUM>. Together, the forward vertical wall <NUM>, rear vertical wall <NUM>, top plenum wall <NUM>, and opposed plenum sidewalls <NUM> form a recessed area around the inlet port <NUM> that enhances suction from the inlet port <NUM> in the plenum <NUM>.

The plenum <NUM> also includes a forward retractable member <NUM> and a rear retractable member <NUM>. The forward retractable member <NUM> and rear retractable member <NUM> are configured to contact the pool surface and extend and retract vertically as they move across obstacles such as large debris or drains on the pool surface.

The top <NUM> includes a cover <NUM> that may be removed via a cover latch <NUM> to access mechanical components inside the housing <NUM>. The cover <NUM> includes a handle <NUM> that allows a user to easily grab the pool cleaner <NUM> to remove it from the pool when necessary.

A particularly advantageous feature of the cover <NUM> is at least one vent mechanism <NUM> formed adjacent the forward end <NUM> of the pool cleaner <NUM>. The vent mechanism <NUM> is configured to allow water from outside the housing <NUM> and cover <NUM> to flow into the housing <NUM> to help prevent loss of suction when the forward end <NUM> extends above the water line of the pool. The vent mechanism <NUM> may be composed of one or more holes defined by the cover <NUM> and extending completely through the cover <NUM>. This advantageous feature is described in more detail later.

In the example shown in the drawings, the vent mechanism <NUM> includes a plurality of vent slits <NUM> formed on opposed sides of the inlet port <NUM>. These vent slits <NUM> extend from a point proximal to the forward end <NUM> toward the rearward end <NUM> and do not extend past the position of the inlet port <NUM>.

The vent mechanism <NUM> need not have the exact construction shown in the drawings or described above. The vent mechanism <NUM>, in certain examples, is positioned proximal to the forward end <NUM>, but does not necessarily have to be on the cover <NUM>.

Referring now to <FIG>, additional details about the forward retractable member <NUM> and rear retractable member <NUM> will now be described. In <FIG>, the forward retractable member <NUM> and rear retractable member <NUM> are shown as transparent features so that their respective interiors are visible. <FIG> is a cross section taken along the plane <NUM>-<NUM> defined by the arrows in <FIG>.

In the example shown, both the forward retractable member <NUM> and rear retractable member <NUM> are composed of a plurality of substantially cylindrical rollers <NUM> that roll independently of one another about a support member <NUM> extending from opposed housing sidewalls <NUM>. The rollers <NUM> have a diameter D3 selected so that an outer surface <NUM> of the rollers may slightly contact or almost contact a either a forward concave wall <NUM> or a rear concave wall <NUM> and the forward vertical wall <NUM> or the rear vertical wall <NUM> of the plenum <NUM>. This construction allows each roller <NUM> to move independently of the other rollers <NUM> over obstacles on the pool surface and to help concentrate suction in the plenum <NUM>.

The retractable members <NUM>, <NUM> have a considerable range of movement. As illustrated by the arrows in <FIG>, the outer surface <NUM> of the rollers <NUM> can extend beyond an outer perimeter <NUM> of the tracks <NUM>.

The construction of the forward retractable member <NUM> and rear retractable member <NUM> is not limited to this example. For example, either or both of the forward retractable member <NUM> and rear retractable member <NUM> may be replaced with flaps instead of rollers. Likewise, the forward retractable member <NUM> and rear retractable member <NUM> may be composed of a single roller <NUM> or flap instead of a plurality of rollers <NUM> or flaps.

Referring to <FIG>, the cover <NUM> has been removed so that the interior of the housing <NUM> is visible and details of the outlet port housing <NUM> can be described. <FIG> is a side view of the outlet port housing <NUM> with nonvisible features shown in dashed lines.

The outlet port housing <NUM> extends from the outlet port <NUM> at a top thereof to a turbine cover <NUM> at a bottom thereof. The turbine cover <NUM> is configured to cover the turbine described below and direct water flow from the turbine up through the outlet port <NUM>. The outlet port <NUM> is defined by a hose nozzle <NUM> that is rotatable about an axis A passing through the cylindrical center of the hose nozzle <NUM>. Making the hose nozzle <NUM> rotatable allows the pool cleaner <NUM> to turn without twisting the suction hose connected to the hose nozzle <NUM>.

The inside of the outlet port housing <NUM>, which is illustrated by dashed lines in <FIG> defines a water flow passage that directs water flow from the turbine <NUM> up through the outlet port <NUM>.

Referring to <FIG> and <FIG>, the pool cleaner <NUM> with the cover <NUM> removed and the outlet port housing <NUM> removed is shown so that details of the drive train <NUM> are visible. The drive train <NUM> is powered by suction that causes the turbine <NUM> to rotate. The motion of the spinning turbine <NUM> is transferred to at least one of the first wheels <NUM> via a plurality of gears in mechanical communication with a drive shaft <NUM> that causes the first wheels <NUM> to turn and power the drive mechanism <NUM> via a pinion gear <NUM>.

In <FIG>, the track <NUM> has been removed so that features of the inner side of first wheel <NUM> are visible. The first wheel <NUM> has a primary wheel gear <NUM> radially spaced from a secondary wheel gear <NUM> opposing one another on an inside peripheral surface of the first wheel <NUM>.

The drive train <NUM> allows the pool cleaner <NUM> to move in the forward direction F and periodically make turns to so that the pool cleaner <NUM> can move to different areas of the pool. The steering operations are controlled by moving the drive shaft <NUM> so that the pinion gear <NUM> engages either the primary wheel gear <NUM> or the secondary wheel gear <NUM>. When the pinion gear <NUM> engages the secondary wheel gear <NUM>, the first wheel <NUM> moves in reverse, which causes the pool cleaner <NUM> to turn.

A cam <NUM> of the drive train <NUM> dictates whether the pool cleaner <NUM> moves in the forward direction F or turning direction T. In the turning direction T, the pool cleaner <NUM> changes direction relative to the forward direction F. Referring to <FIG>, the perimeter of the cam <NUM> includes alternating radially enlarged sections <NUM> and radially constricted sections <NUM>. The cam <NUM> is rotated by the turbine <NUM> through use of reduction gears <NUM>.

A drive shaft contactor <NUM> mechanically connects the drive shaft <NUM> with the cam <NUM> and is operable to move the pinion gear <NUM> from a forward driving position to a turning position. In <FIG>, the pinion gear <NUM> is in the forward driving position in which it engages the primary wheel gear <NUM>. In <FIG>, the pinion gear <NUM> is in the turning position in which it engages the secondary wheel gear <NUM>.

The drive shaft contactor <NUM> includes a rotatable cam contacting member <NUM> that directly contacts the cam <NUM> and is biased against the cam <NUM> with at least one spring <NUM> or the like that presses upward against an arm <NUM>. As shown in <FIG>, when the cam contacting member <NUM> is in contact with a radially enlarged section <NUM> of the cam <NUM>, the pinion <NUM> is in the forward driving position. As shown in <FIG>, when the cam contacting member <NUM> is in contact with a radially constricted section <NUM> of the cam <NUM>, the pinion <NUM> is biased by the spring <NUM> into the turning position.

A particularly advantageous feature of the pool cleaner <NUM> will now be described by referring to <FIG> in which the retractable members <NUM>, <NUM> have been removed from the pool cleaner <NUM> for better visibility of certain features. A problem with pool cleaners is that they sometimes become stuck on drain covers D raised above the pool surface S. The pool cleaner <NUM> described here is configured to substantially prevent itself from becoming stuck on submerged obstacles such as drain covers D by including a protruding member <NUM>.

The protruding member <NUM> extends downwardly from the top plenum wall <NUM> and longitudinally between the forward vertical wall <NUM> and rear vertical wall <NUM>. The protruding member <NUM> is positioned between the inlet port <NUM> and one of the plenum sidewalls <NUM>. A terminal bottom end <NUM> of the protruding member <NUM> is positioned higher than a terminal bottom end <NUM> of the plenum sidewall <NUM>. The forward surface <NUM> of the protruding member <NUM> tapers downwardly and rearwardly as it moves down from top plenum wall <NUM> to the terminal bottom end <NUM>. The rear surface <NUM> of the protruding member <NUM> tapers upwardly and rearwardly as it moves up from the terminal bottom end <NUM> to the top plenum wall <NUM>. This tapered shape allows the protruding member <NUM> to slide across surfaces easier than it otherwise would if the protruding member <NUM> were rectangular with sharp vertices.

As shown in <FIG>, when the protruding member <NUM> contacts the drain cover D, it causes the pool cleaner <NUM> to tilt, which ensures at least one of the tracks <NUM> can maintain contact with the pool surface to prevent the pool cleaner <NUM> from getting stuck.

Another advantageous feature of the pool cleaner <NUM> will now be described by referring to <FIG>. As illustrated in <FIG>, when the pool cleaner <NUM> climbs vertical pool walls W, it can sometimes rise partially above the pool's waterline. When this happens to a conventional suction pool cleaner, the inlet port sucks in air, causing the pool cleaner to lose suction and temporarily stop working until suction is regained. The pool cleaner <NUM> described here is designed to prevent loss of suction in this situation.

<FIG> indicate the position of the waterline on the pool cleaner <NUM> in <FIG> from different points of view. In <FIG>, the forward retractable member <NUM> has been removed for better visibility of certain features. In <FIG>, the cover <NUM> has also been removed for better visibility of certain features.

Suction loss is prevented by water passing through the vent mechanism <NUM> through the housing <NUM> and out one or more water ports <NUM> formed on the bottom <NUM>. This water then falls over the plenum <NUM> and substantially prevents loss of suction.

In the example shown, the water ports <NUM> are positioned directly beneath the vent mechanism <NUM> and forward from the forward vertical wall <NUM> closer to the forward end <NUM>. The water ports <NUM> are also positioned directly above the forward retractable member <NUM> as can also be seen in <FIG>. As used herein, the term "directly" means along the same vertical plane passing through the pool cleaner when it is in the orientation shown in <FIG>.

In the example shown, there are two water ports <NUM> positioned on either side of the inlet port <NUM>. This permits water to flow across both sides of the plenum <NUM>. In other examples, there may be one elongated water port <NUM> extending across both sides of the plenum <NUM> or there may more than two water ports <NUM> positioned about either side of the plenum <NUM>.

Referring to <FIG>, the track mechanism <NUM> construction will be described in more detail. The track <NUM> is made of flexible plastic or rubber material suitable for use on a pool cleaner. The outer perimeter <NUM> of the track <NUM> includes treads <NUM> for enhanced traction with the pool surface. An inner perimeter <NUM> of the track includes a raised ridge <NUM> extending substantially completely around the inner perimeter <NUM>. The raised ridge <NUM> is sized to slide into a first groove <NUM> formed on a perimeter of the first wheel <NUM> and a second groove <NUM> formed on a perimeter of the second wheel <NUM>. By making the raised ridge <NUM> mate with the first <NUM> and second <NUM> grooves, the track <NUM> is prevented from sliding off the first wheel <NUM> and second wheel <NUM>.

Referring also to <FIG>, an advantageous safety feature of the pool cleaner <NUM> will be described. One of the problems with conventional track-driven pool cleaners is that they have large spaces between the tracks and wheels where things such as fingers, hair, and clothing can become stuck. The pool cleaner <NUM> described here overcomes this problem by including a guard <NUM> that fits between the first wheel <NUM> and second wheel <NUM>. As shown in <FIG>, the guard <NUM> substantially fills the space between the first wheel <NUM> and second wheel <NUM> to prevent object from entering the space.

In <FIG>, the track mechanism <NUM> is removed so that the connection mechanism between the guard <NUM> and housing <NUM> is visible. The guard <NUM> includes an insertion member <NUM> that is inserted into a guard receiving opening <NUM> defined by the side of the housing <NUM>. A forward section <NUM> of the guard and a rear section <NUM> of the guard substantially match the curvature of the second wheel <NUM> and first wheel <NUM> respectively so that there is only a small gap between these wheels and the guard <NUM>.

Most parts of the pool cleaner <NUM> may be constructed of submersible plastic material and may be printed, machined, or molded to the desired shape. Where needed, parts may be connected together with substantially corrosion-proof fasteners such as stainless steel screws, washers, nuts, and the like. The first and second wheels may include conventional wheel bearings to aid rotation.

Claim 1:
A pool cleaner (<NUM>) comprising:
a drive mechanism (<NUM>) operable to drive the pool cleaner along a submerged surface of a pool in a forward direction (F);
a housing (<NUM>) carried by the drive mechanism, the housing having a bottom (<NUM>) with an inlet port (<NUM>) that receives debris removed from the submerged surface; and
an outlet port (<NUM>) in fluid communication with the inlet port (<NUM>):
characterised in that:
the pool cleaner (<NUM>) further comprises:
a plenum (<NUM>) on the bottom for enhancing suction around the inlet port (<NUM>);
a vent mechanism (<NUM>) defining at least one opening through the housing forward the outlet port (<NUM>); and
a water port (<NUM>) defining at least one opening on the bottom, the water port (<NUM>) being in fluid communication with the vent mechanism (<NUM>);
wherein when a forward end of the pool cleaner (<NUM>) extends above a waterline of the pool, water flows through the vent mechanism (<NUM>) and the water port (<NUM>) over the plenum (<NUM>) so as to prevent loss of suction at the inlet port (<NUM>).