Patent Description:
Many conventional pools are provided with a water outlet and a water inlet to circulate water for filtration and for heating, with a pump drawing water out of the pool through the water outlet and returning the water back to the pool through the water inlet. Some examples are disclosed in documents <CIT>, <CIT>, <CIT>, <CIT> or in <CIT>. Many conventional pools also include a filter at the water outlet of the pool. Such filters commonly include a shield to protect a user's skin or hair from being drawn into or onto the water outlet as a result negative pressure at the water outlet. As shown in <FIG>, a pool <NUM> is provided with a water inlet <NUM> in fluid communication with an external pump <NUM> and a water outlet <NUM> with a filter <NUM>. If the filter <NUM> is removed, but not replaced with a new filter, suction at the water outlet may draw the user's body or hair against or into the water outlet. In some cases, this suction may be powerful enough that the user may be unable to free themself from the water outlet, which can result in injury to the user.

In some conventional pools, a water circulation system is provided with two water outlets to increase user safety. As shown in <FIG>, in addition to a water outlet <NUM> with a filter 5a, another water outlet is provided with a filter 5b. In this way, when one of the water outlets is blocked, the suction at the blocked water outlet <NUM> is reduced because water continues to flow out of the other (i.e., unblocked) water outlet, so that the danger to the user can be avoided. The two water outlets are typically spaced apart by a long distance to prevent one user from being able to make contact with the two water outlets at the same time so as to ensure safety. For some pools, such as massage pools and above-ground pools, the available area is limited, and therefore, the positions of the water outlets can affect a user's experience, so large spacing between two water outlets can result in a waste of usable space. Furthermore, large spacing between multiple water outlets can reduce production efficiency.

In accordance with various embodiments of the present disclosure, a water circulation system for a pool comprises a water outlet assembly mounted to an inner wall of the pool and in fluid communication with an external pump through a water outlet pipe. The water circulation system also includes an air inlet assembly mounted to the pool a preset distance from the water outlet assembly, and an air outlet assembly attached to the water outlet assembly and in fluid communication with the water outlet assembly. The water circulation system also includes an air inlet passage connecting the air inlet assembly to the air outlet assembly, wherein fluid can enter the air inlet assembly and be introduced to the water outlet assembly through the air outlet assembly.

The air inlet assembly of the water circulation system comprises an air inlet outer cover mounted to the inner wall of the pool, a top wall of the pool, or an outer wall of the pool. The air inlet outer cover includes a plurality of air inlets. The air inlet passage is located between the inner wall of the pool and the outer wall of the pool or in a pool body adjacent to the inner wall of the pool; the air inlet passage is connected to each of the air inlet outer cover and the air outlet assembly by joints.

In accordance with various embodiments of the present disclosure, the air inlet assembly is mounted to the inner wall of the pool, and the fluid includes water from the pool.

Preferably, at least one of the joints is fixed with a rubber coating to the inner wall of the pool, or to the top wall of the pool, or to the outer wall of the pool. Alternatively, at least one of the joints is integrally formed with the air inlet outer cover or the air outlet assembly.

The air outlet assembly of the water circulation system for a pool comprises a shell fixed to the inner wall of the pool; the shell includes an installation port for receiving the water outlet assembly; the shell also includes a plurality of air inlets, at least some air inlets of the plurality of air inlets are located above a desired water level of the pool. The shell includes an internal cavity defining the air inlet passage. The air outlet assembly comprises a shell fixed to the inner wall of the pool; the shell includes a first installation port for receiving the air inlet passage and a second installation port for receiving the water outlet assembly, and wherein the shell includes an internal cavity through which the air inlet passage is in fluid communication with the water outlet assembly. The shell of the air outlet assembly comprises a first shell and a second shell connected to each other, wherein at least one of the first shell and the second shell defines the first installation port and the second installation port, and wherein the first installation port and the second installation port include air holes in fluid communication with the internal cavity.

In the water circulation system for a pool, the water outlet assembly comprises a water outlet device and the water outlet pipe through which the water outlet device is connected to the external pump; the water outlet device includes a circumferential side wall, wherein the water outlet device is mounted to the inner wall of the pool and at least partially located inside the shell, wherein the water outlet device includes a plurality of water outlet orifices in fluid communication with water in the pool, and wherein the water outlet device includes a plurality of through holes in the circumferential side wall. The plurality of through holes are circumferentially arranged around the circumferential side wall of the water outlet device and adjacent to the inner wall of the pool.

The water outlet device is connected to the water outlet pipe via a water outlet device joint. The plurality of through holes of the water outlet device are located inside of the water outlet device joint.

The water outlet assembly includes a water outlet pipe connector connecting the water outlet device to the water outlet pipe; the water outlet pipe connector includes a water outlet pipe joint connected to a water outlet device joint, with the water outlet pipe joint connected directly to the water outlet pipe, and the water outlet device joint connected directly to the water outlet device; the plurality of through holes of the water outlet device are located adjacent to the water outlet device joint. The water outlet pipe connector further comprises a flexible connector attached to the inner wall of the pool; the water outlet pipe joint is attached to the inner wall of the pool by the flexible connector. The water outlet pipe joint is connected to the flexible connector by secondary injection molding.

The shell of the air outlet assembly and the water outlet assembly form a substantially closed space when the water outlet assembly is blocked.

The air outlet assembly is in fluid communication with the water outlet assembly when the water outlet assembly is not connected to a filter, and wherein the air outlet assembly is not in fluid communication with the water outlet assembly when the water outlet assembly is connected to the filter. The water circulation system for a pool according further comprising a flow blocking member configured to selectively block fluid communication between the through holes of the water outlet device and the water outlet assembly. The flow blocking member comprises a connection interface of the filter. The water circulation system for a pool further comprising a base and an elastic member, the base being located inside the shell of the air outlet assembly and the elastic member being sheathed on a side wall of the water outlet device, wherein the elastic member abuts against one of the inner wall of the pool and the inner wall of the shell of the air outlet assembly to bias the base away from the one of the inner wall of the pool and the inner wall of the housing of the air outlet assembly. The flow blocking member comprises the base. In accordance with various embodiments of the present disclosure, a water circulation system for a pool comprises a water inlet assembly mounted to an inner wall of the pool and in fluid communication with an external pump through a water inlet pipe. The water circulation system also includes a water outlet assembly mounted to the inner wall of the pool and in fluid communication with the external pump through a water outlet pipe, and an auxiliary suction assembly mounted to the inner wall of the pool. The auxiliary suction assembly is in fluid communication with the water outlet assembly when the water outlet assembly is disconnected from a filter, and the auxiliary suction assembly is blocked from fluid communication with the water outlet assembly when the water outlet assembly is connected to the filter.

In accordance with various embodiments of the present disclosure, a water circulation system for a pool comprises a water outlet assembly mounted to an inner wall of the pool, the water outlet assembly being configured to draw water out of the pool. The water circulation system also includes an air inlet assembly mounted to the pool spaced apart from the water outlet assembly and configured to draw in ambient air. The water circulation system also includes an air outlet assembly in communication with the water outlet assembly for introducing air to the water outlet assembly when the water outlet assembly is blocked, and an air inlet passage configured to convey air from the air inlet assembly to the water outlet assembly.

In accordance with various embodiments of the present disclosure, a water circulation system for a pool comprises a water outlet assembly mounted to an inner wall of the pool. The water outlet assembly is configured to draw water out of the pool. The water circulation system also includes an auxiliary suction assembly mounted to the inner wall of the pool. The auxiliary suction assembly is in fluid communication with the water outlet assembly when the water outlet assembly is disconnected from a filter for introducing fluid to the water outlet assembly when the water outlet assembly is blocked. The auxiliary suction assembly is blocked from fluid communication with the water outlet assembly when the water outlet assembly is connected to the filter.

In accordance with various embodiments of the present disclosure, a pool comprises a water circulation system according to one of the embodiments of the present invention. The pool is an inflatable pool.

The air inlet passage is disposed in an air chamber of the inflatable pool.

To understand the present disclosure, it will now be described by way of example, with reference to the accompanying drawings in which implementations of the disclosure are illustrated and, together with the description below, serve to explain the principles of the disclosure.

The present disclosure provides exemplary embodiments of a water circulation system for a pool, and a pool fitted with such a water circulation system. The exemplary embodiments of the present disclosure are described below with reference to the drawings for illustration. The structural positions of various components, e.g., upper, lower, top, bottom, etc., are not absolute, but relative. The orientation expressions are appropriate when the various components are arranged, as shown in the figures, but should change accordingly when the positions of the various components in the figures change.

The pool or pools described herein may be above-ground pools or in-ground pools, in which the above-ground pools include, but are not limited to, inflatable pools, massage pools, hot tubs, support pools and the like. An inflatable pool is shown as an example.

As used herein, "inner" refers to the direction toward a water storage area of a pool, and "outer" refers to the direction towards the exterior of the whole pool. "Gas" refers to any gas, such as air, that can be introduced from the outside atmosphere or from an apparatus, and "fluid" includes both gas and liquid, such as a gas flow and a water flow.

A water circulation system for a pool generally comprises a water inlet assembly <NUM> and a water outlet assembly <NUM>. As shown in <FIG>, the water inlet assembly <NUM> is mounted to an inner wall <NUM> of the pool <NUM>, with a water inlet device <NUM> in fluid communication with an external pump <NUM> through a water inlet pipe <NUM>. A water outlet assembly <NUM> is mounted to the inner wall <NUM>, with a water outlet device <NUM> in fluid communication with the external pump <NUM> through a water outlet pipe <NUM>. A filter <NUM> may be mounted to the water outlet device <NUM>.

According to various embodiments of the present disclosure, a water circulation system with an air inlet assembly <NUM> and an air outlet assembly <NUM> is provided, wherein the air inlet assembly <NUM> is connected to the air outlet assembly <NUM> through an air inlet passage <NUM>. The air inlet assembly <NUM> is mounted to the pool at a preset distance from a water outlet assembly <NUM>, and the air outlet assembly <NUM> is attached to the water outlet assembly <NUM> on the inner wall <NUM> of the pool and in fluid communication with the water outlet assembly <NUM>. When a water outlet of the water outlet assembly <NUM> is blocked, the water circulation system can introduce external air from the air inlet assembly <NUM> to the air outlet assembly <NUM> through the air inlet passage <NUM> and then to the water outlet assembly <NUM> via the air outlet assembly <NUM>. In this way, when the water outlet assembly <NUM> is not blocked, water flow from the pool can flow into a water outlet pipe <NUM> in a normal way, and then flow into the pool via an external pump <NUM> and a water inlet pipe <NUM>. When the water outlet assembly <NUM> is blocked by an obstruction, such as part of a user's body or hair, the external pump <NUM> continues operation, and negative pressure is generated at the water outlet of the water outlet assembly <NUM>. This negative pressure can make it difficult to remove the obstruction or body from the water outlet assembly <NUM>. However, with the water circulation system of the present disclosure, air is introduced to the flow path of water flow to reduce the negative pressure at the water outlet, thereby reducing the suction force at the water outlet which can act upon the user's body or hair, the resulting reduction of suction force effectively protecting the user.

In various embodiments, the air outlet assembly <NUM>, <NUM> of the water circulation system may be configured to be in fluid communication with the water outlet assembly <NUM> when the water outlet assembly <NUM> is not connected to a filter <NUM>, but not in fluid communication with the water outlet assembly <NUM> when the water outlet assembly <NUM> is connected to the filter <NUM>. In this way, when the filter <NUM> is not installed at the water outlet assembly <NUM>, water and/or air can flow into the water outlet pipe <NUM> from the air outlet assembly <NUM>, <NUM>, as well as from the water outlet assembly <NUM>. Even if the water outlet of the water outlet assembly <NUM> is blocked, water flow or air flow can still flow from the air outlet assembly <NUM>, <NUM> to the water outlet pipe <NUM>, thereby effectively protecting the user. When the filter <NUM> is installed on the water outlet assembly <NUM>, water flow can only flow into the water outlet pipe <NUM> via the filter <NUM>, thereby providing the filtering effect.

Various embodiments are described below in conjunction with the drawings so that those skilled in the art could fully understand the present disclosure. Some components, such as the water inlet assembly, the external pump and the filter, may comprise any suitable known components, and therefore, are not further described below.

As mentioned above, the air outlet assembly <NUM>, <NUM> of the present disclosure may be configured to accommodate the filter <NUM>. <FIG> show a water circulation system for a pool according to a first embodiment of the present disclosure. In various embodiments, and as shown in <FIG>, the air outlet assembly <NUM> comprises a shell <NUM> fixed to the inner wall <NUM> of the pool. The shell <NUM> includes an installation port <NUM> for receiving the water outlet assembly <NUM>. The shell <NUM> defines a plurality of air inlets, such as those provided by grille <NUM>. In various embodiments, at least part of the grille <NUM> is located above a desired in-use water level of the pool, and the shell <NUM> has an internal cavity to define a fluid passage in fluid communication with the water outlet assembly <NUM>. As shown in the embodiment of <FIG>, the installation port <NUM> of the shell <NUM> may also receive the water inlet assembly <NUM>. Particularly, in this embodiment, the shell <NUM> serves as both an air inlet assembly and an air outlet assembly, and the internal cavity of the shell <NUM> also defines the air inlet passage. Other embodiments of the present disclosure include the air inlet assembly mounted to the inner wall, or to the top wall or to the outer wall of the pool. In some embodiments, the pool <NUM> is an inflatable pool, and the air inlet passage <NUM> is disposed in an air chamber of the inflatable pool.

In the embodiment shown in <FIG>, the water outlet device <NUM> is at least partially located inside the shell <NUM>, and the water outlet device <NUM> includes a plurality of water outlet orifices <NUM> and a plurality of through holes <NUM> in a side wall thereof. In addition, a circumferential side wall of the water outlet device <NUM> includes external threads that cooperate with internal threads of the filter <NUM>, so that a user can conveniently install the filter <NUM> onto the water outlet device <NUM>. The plurality of through holes <NUM> may be on or adjacent to the external threads of the water outlet device <NUM>, but the through holes <NUM> do not affect the connection function of the external threads. In various embodiments, the water outlet device may be provided with a water outlet device joint 42b connected to the inner wall of the pool. The water outlet device joint 42b may be integrally formed or separately connected with the water outlet device <NUM>. The through holes <NUM> may be circumferentially arranged in the side wall of the water outlet device <NUM> and adjacent to the water outlet device joint 42b, as shown in <FIG>, thereby providing fluid communication between the internal cavity of the shell <NUM> and the water outlet assembly <NUM> via the through holes <NUM>.

In various embodiments, the air outlet assembly <NUM> is in fluid communication with the water outlet assembly <NUM> when the water outlet assembly <NUM> is not connected to the filter <NUM>, and the air outlet assembly is not in fluid communication with the water outlet assembly when the water outlet assembly <NUM> is connected to the filter <NUM>. Advantageously, the through holes <NUM> of the water outlet device <NUM> may be selectively blocked from fluid communication with the air outlet assembly <NUM> by a water flow blocking member. In this embodiment, an elastic member <NUM>, such as a coil spring, is sheathed on a side wall of the water outlet device <NUM>. A base <NUM> is provided inside of the shell <NUM> such that the elastic member <NUM> abuts against the inner wall <NUM> of the pool or the inner wall of the shell <NUM>. That is, the base <NUM> serves as the water flow blocking member, and the elastic member <NUM> biases the base <NUM> away from the through holes <NUM>. When the water outlet assembly <NUM> is not connected to the filter <NUM>, referring to <FIG> and <FIG>, after the pump <NUM> is started, part of the water flow and air enter the shell <NUM> through the grille <NUM> of the shell <NUM>, and then enters the water outlet pipe <NUM> from the shell <NUM> via the through holes <NUM> of the water outlet device <NUM>, as indicated by the depicted arrows. At the same time, the other part of the water flow enters the water outlet pipe <NUM> through the water outlet orifices <NUM> of the water outlet device <NUM>. The water flow then flows through the pump <NUM> and the water inlet pipe <NUM> from the water outlet pipe <NUM>, finally returning to the pool <NUM> through the water inlet device <NUM>, thereby providing circulating filtration for the pool.

It should be understood here that, in this embodiment, when the water outlet assembly is not connected to the filter <NUM>, if the water outlet assembly is blocked by a portion of a human body, hair or other obstruction, because the air outlet assembly is in communication with the water outlet assembly, air can enter through the grille <NUM> of the shell, enter the water outlet pipe <NUM> via the through holes <NUM> of the water outlet device <NUM>, then flow through the pump <NUM> and the water inlet pipe <NUM> from the water outlet pipe <NUM>, and finally return to the pool <NUM> through the water inlet device <NUM>. That is, when the water outlet device is not connected to the filter <NUM> and the water outlet device is blocked, because air in the fluid path continues to circulate, the negative pressure at the water outlet device is partially reduced, and the user can free themself from suction at the water outlet more easily to avoid injury.

After the filter <NUM> is installed to the water outlet assembly <NUM>, as shown in <FIG> and <FIG>, the filter <NUM> is provided with a plurality of filter ports <NUM> and a connection interface <NUM>. Once the connection interface <NUM> of the filter <NUM> is made, for example, by means of threaded connection, to the water outlet device <NUM>, the connection interface <NUM> abuts against the base <NUM>, urging the base <NUM> to move toward the water outlet pipe <NUM>, compressing the elastic member <NUM> and causing the base <NUM> to block the through holes <NUM> in the side wall of the water outlet device <NUM>. At this time, the fluid passage in the shell <NUM> is not in communication with the water outlet device <NUM>, and water flow cannot enter the water outlet pipe <NUM> via the through holes <NUM>, but can only flow in through the filter ports <NUM> of the filter <NUM>, as indicated by the depicted arrows, and then return to the pool via the water outlet pipe <NUM>, the pump <NUM>, the water inlet pipe <NUM> and the water inlet device <NUM>. After the filter <NUM> is removed, it should be understood that the base <NUM> is reset under the action of the elastic member <NUM> to abut against the inner wall of the shell <NUM>, and the through holes <NUM> are in fluid communication with the shell <NUM> again. In this way, after the filter <NUM> is installed, water flow can only flow into the water outlet pipe via the filter, thereby providing the filtering effect.

In various embodiments, and as shown in <FIG> and <FIG>, the water outlet assembly <NUM> may comprise a water outlet pipe connector connecting the water outlet pipe <NUM> in fluid communication with the water outlet device <NUM>. In various embodiments, the water outlet pipe connector comprises a water outlet pipe joint <NUM> connected to the water outlet pipe <NUM>, and a water outlet device joint 42b connected to the water outlet pipe joint <NUM> for connection to the water outlet device <NUM>. As shown in <FIG>, one end of the water outlet pipe joint <NUM> may be, for example, connected to the water outlet pipe <NUM> by a nut <NUM>, and the other end may be, for example, fixed to the inner wall <NUM> of the pool by a flexible connector <NUM> fixed to the inner wall <NUM> of the pool. In various embodiments, the water outlet pipe joint <NUM> may be connected to the flexible connector <NUM> by means of secondary injection molding. In addition, the water outlet device joint 42b is hermetically connected to the inner wall <NUM> of the pool.

<FIG> show a water circulation system according to a second embodiment of the present disclosure. This second embodiment is different from the embodiment described above and shown in <FIG> in that the water outlet device <NUM> of <FIG> does not include an elastic member or a base. Instead, the water flow blocking member is the connection interface <NUM> of the filter <NUM>, and when the filter <NUM> is installed to the water outlet device <NUM>, the through holes <NUM> are directly blocked by the connection interface <NUM>, as shown in <FIG>. Thus, in this configuration, water flow cannot enter the water outlet pipe from the shell <NUM>, or only an extremely small amount of water flow can enter the water outlet pipe from the shell <NUM>. Similarly, water flows in from the filter ports <NUM> of the filter <NUM>, as indicated by the depicted arrows, and then returns to the pool via the water outlet pipe <NUM>, the pump <NUM>, the water inlet pipe <NUM> and the water inlet device <NUM>.

<FIG> show a water circulation system according to a third embodiment of the present disclosure. In this embodiment, the air inlet assembly <NUM> comprises an air inlet outer cover <NUM> installed on the inner wall <NUM> of the pool. The air inlet outer cover <NUM> is provided with a plurality of air inlets <NUM>, for example, as the air inlets of the outer cover grille. As shown in <FIG>, the air inlet passage <NUM> is arranged between the inner wall <NUM> and the outer wall <NUM> of the pool and is connected to the air inlet outer cover <NUM> and the air outlet assembly <NUM> by means of joints, respectively. In this way, in embodiments in which a cavity is provided within the walls of the pool (for example, such as may be provided by an inflatable pool), the air inlet passage can be arranged within the inflatable chamber like the water inlet pipe and the water outlet pipe, so as to avoid failure due to damage that may otherwise be sustained when placed outside of the wall of the pool. The air inlet passage <NUM> may comprise, for example, a flexible hose, and may be thus easily sheathed on the joint to achieve fluid communication between the air inlet outer cover <NUM> and the air outlet assembly <NUM>.

In this embodiment, the air outlet assembly <NUM> comprises a shell <NUM> fixed to the inner wall <NUM> of the pool. As shown in <FIG>, the shell <NUM> is provided with a first installation port <NUM> for installation of the air inlet passage <NUM> and a second installation port <NUM> for installation of the water outlet assembly, wherein the shell <NUM> has an internal cavity to connect the air inlet passage with the water outlet assembly.

The air inlet assembly <NUM> may be mounted at a preset distance from the water outlet assembly <NUM>. In this embodiment, the air inlet outer cover <NUM> is located at an upper part of the inner wall <NUM> of the pool. In various embodiments, at least some of the air inlets <NUM> are above the in-use water level of the pool. In this way, since at least some of the air inlets <NUM> of the air inlet outer cover <NUM> are exposed to the outside atmosphere when in normal use, even if the air inlets below the water surface are blocked, the flow of gas, such as air, can still be introduced through the air inlets <NUM> above the water surface, thus ensuring that fluid flow can continue to enter the air outlet assembly <NUM> from the air inlet passage <NUM> and then enter the water outlet pipe <NUM> from the air outlet assembly <NUM>. Since air enters the water outlet pipe <NUM> more easily, the negative pressure at the water outlet of the water outlet assembly <NUM> is greatly reduced, thereby reducing the risk of drawing the user's body or hair against or into the water outlet assembly <NUM>.

In various embodiments, and as shown in <FIG> and <FIG>, the air inlet passage <NUM> may be connected to the air inlet outer cover <NUM> and the shell <NUM> by means of a joint provided on the air inlet outer cover <NUM> and the shell <NUM>, where each joint may be integrally molded or cooperatively connected with the air inlet outer cover <NUM> or the shell <NUM>. Specifically, a first joint <NUM> may be integrally formed on the air inlet outer cover <NUM>, and a second joint <NUM> may be connected to the shell <NUM>. In various different embodiments, at least one of the joints <NUM>, <NUM> may be fixed with a rubber coating to the inner wall of the pool, the top wall of the pool, or the outer wall of the pool. In various embodiments at least one of the joints <NUM>, <NUM> may be integrally formed with the air inlet outer cover <NUM> and/or the shell <NUM> of the air outlet assembly <NUM>.

Similar to the first embodiment, in this embodiment, an elastic member <NUM> is sheathed on the side wall of the water outlet device <NUM>, and the base <NUM> serves as a water flow blocking member. When the water outlet assembly <NUM> is not connected to the filter <NUM>, as shown in <FIG>, part of the fluid flow (including air and/or water) enters the shell <NUM> from the air inlets <NUM> of the air inlet outer cover <NUM> via the air inlet passage <NUM>, as indicated by the depicted arrows, and then enters the water outlet pipe <NUM> from the shell <NUM> via the through holes <NUM> of the water outlet device <NUM>. At the same time, another part of the fluid flow enters the water outlet pipe <NUM> through the water outlet orifices <NUM> of the water outlet device <NUM>. After the filter <NUM> is installed on the water outlet assembly <NUM>, as shown in <FIG>, the connection interface <NUM> of the filter <NUM> abuts against the base <NUM>, urging the base <NUM> to move towards the water outlet pipe <NUM> and squeezing the elastic member <NUM>, causing the base <NUM> to block the through holes <NUM> in the side wall of the water outlet device <NUM>. Water flows in from the filter ports <NUM> of the filter <NUM>, as indicated by the depicted arrows, and then returns to the pool via the water outlet pipe <NUM>, the pump <NUM>, the water inlet pipe <NUM> and the water inlet device <NUM>.

<FIG> show a water circulation system according to a fourth embodiment. The water circulation system of <FIG> is different from the water circulation system shown in <FIG> in that the water outlet device <NUM> is not provided with an elastic member or a base. In addition, as shown in <FIG>, the shell <NUM> of the water outlet assembly includes an annular wall <NUM> extending axially towards the internal cavity, and an opening <NUM> formed in the annular wall <NUM>.

When the water outlet device <NUM> is not connected to the filter <NUM>, as shown in <FIG> and <FIG>, part of the fluid flow (including air and/or water) enters the shell <NUM> from the air inlets <NUM> of the air inlet outer cover <NUM> via the air inlet passage <NUM>, as indicated by the depicted arrows, and then enters the water outlet pipe <NUM> from the opening <NUM> of the shell <NUM> via the through holes <NUM> of the water outlet device <NUM>. At the same time, another part of the fluid flow enters the water outlet pipe <NUM> through the water outlet orifices <NUM> of the water outlet device <NUM>. Thus, when the filter <NUM> is connected to the water outlet device <NUM> of the water outlet assembly, as shown in <FIG> and <FIG>, the connection interface <NUM> of the filter <NUM> serves as a water flow blocking member to block the through holes <NUM>, and thus as shown in <FIG> and <FIG>, water flow can only flow into the water outlet pipe <NUM> from the filter ports <NUM> of the filter <NUM>, as indicated by the depicted arrows.

<FIG> show a water circulation system for a pool according to a fifth embodiment. Similar to other embodiments, the air inlet assembly <NUM> of the fifth embodiment comprises an air inlet outer cover <NUM> installed to the inner wall <NUM> of the pool. The air inlet outer cover <NUM> is provided with a plurality of air inlets <NUM> in the form of a grille, as shown in <FIG>. In the illustrated embodiment, the air outlet assembly <NUM> comprises a shell <NUM> fixed to the inner wall <NUM> of the pool, and the shell <NUM> is provided with a first installation port <NUM> for installation of the air inlet passage <NUM> and a second installation port <NUM> for installation of the water outlet assembly <NUM>. Similarly, a recessed portion that sinks into the internal cavity of the shell <NUM> may be formed at the second installation port <NUM> to receive at least part of the water outlet assembly. Optionally, the first installation port <NUM> and the second installation port <NUM> may be provided with first air holes and second air holes in fluid communication with the internal cavity. For example, second air holes <NUM> may be formed in the annular side wall of the recessed portion at the second installation port <NUM>, as shown in <FIG>.

In this embodiment, the water outlet device <NUM> is received in the recessed portion at the second installation port <NUM> and is thus at least partially located inside of the shell <NUM>. In this way, after the water outlet is installed, an annular gap may be formed between the outer circumference of the water outlet device and the shell <NUM>, more specifically, between the outer circumference of the water outlet device and the inner circumference of the recessed portion, as shown in <FIG>. As shown in more detail in <FIG>, the water outlet device <NUM> comprises a plurality of water outlet orifices <NUM>, such as a plurality of water outlet orifices 421a provided on an end surface and a plurality of water outlet orifices 421b provided on a side surface to achieve a certain filtering effect. The plurality of water outlet orifices <NUM> may have substantially the same size and/or shape. Alternatively, the plurality of water outlet orifices <NUM> may have different shapes and/or sizes. Advantageously, a plurality of through holes <NUM> are circumferentially arranged adjacent to the inner wall of the pool on the circumferential side wall of the water outlet device <NUM>. Similarly, second air holes <NUM>, adjacent to the second installation port <NUM>, are circumferentially arranged adjacent to the inner wall of the pool such that fluid communication exists between the air outlet assembly and the water outlet assembly through the second air holes <NUM> and the through holes <NUM>. Advantageously, in the illustrated embodiment, the first installation port <NUM> and the second installation port <NUM> of the shell <NUM> are configured such that when the water outlet assembly is blocked, and more specifically, when the gap between the outer circumference of the water outlet device <NUM> and the inner circumference of the recessed portion of the shell <NUM> is blocked, as shown in <FIG>, the shell <NUM> and the water outlet device <NUM> form a substantially closed space. When the water outlet device <NUM> is blocked but this gap is not blocked, as shown in <FIG>, the water outlet assembly is still in fluid communication with the pool. When this gap is blocked, for example, if the water outlet device <NUM> is blocked by a portion of a user's body, a substantially closed space is formed between the shell <NUM> and the water outlet device <NUM>. It should be understood that "closed" here does not means being completely closed. In a closed case, a large amount of fluid is blocked, and therefore, cannot enter from the water outlet device; however, a small amount of fluid may still flow into the shell <NUM>. At this time, water flow cannot smoothly enter the water outlet pipe <NUM> from the water outlet device <NUM>. Due to the operation of the pump, the internal pressure of the outlet pipe is reduced; external air enters the air outlet assembly from the air inlet assembly through the air inlet passage and is then introduced into the water outlet pipe through the through holes of the water outlet device; and fluid continues to circulate to partially reduce the negative pressure at the water outlet device, so that a user's body may escape from the water outlet device more easily to avoid injury.

When the filter <NUM> is installed on the water outlet device <NUM> by means of threads, the through holes <NUM> are blocked by the connection interface <NUM> of the filter, so that water flow can only be circulated through the filter <NUM> and the water outlet device <NUM>. At this time, the filter ports of the filter <NUM>, for example, in the form of a grille, are kept at a certain distance from the water outlet device, which can ensure that the water outlet device will not be blocked. At the same time, water flows through a filter element of the filter to filter the water flowing therethrough.

In various embodiments, as described above, the water outlet device <NUM> may be connected to the water outlet pipe <NUM> via an integrally molded or separately connected water outlet device joint. For example, as shown in <FIG>, the water outlet device may comprise a water outlet device portion 42a and a water outlet device joint 42b, and the water outlet device joint 42b may pass through the second installation port <NUM>. In this embodiment, the plurality of through holes <NUM> are provided in the circumferential side wall of the water outlet device joint 42b. When the water outlet device <NUM> is installed with the water outlet pipe <NUM> via the shell <NUM> of the air outlet assembly <NUM>, as shown in in exploded form in <FIG>, the water outlet device joint 42b can pass through the second installation port <NUM> of the shell <NUM>, and the water outlet device joint 42b is fixed to the pipe joint <NUM> of the water outlet pipe <NUM> with a threaded connection. At the same time, the second air holes <NUM> of the second installation port <NUM> of the shell <NUM> may be in fluid communication with the through holes <NUM> of the water outlet device.

The connection between the water outlet device <NUM> and the water outlet pipe <NUM> takes the convenience of disassembly into consideration, while the connection between the air inlet outer cover <NUM> and the air inlet passage <NUM> and the connection between the air inlet passage <NUM> and the shell <NUM> of the air outlet assembly may include connections configured for ease of assembly and disassembly. For example, as shown in <FIG>, the air inlet outer cover <NUM> may be fixedly connected to the first joint <NUM> connected to the air inlet passage <NUM> by screws, and the first joint <NUM> may be mounted to the inner wall of the pool by a rubber coating. Additionally, the first joint <NUM> may be welded to the inner wall of the pool at high frequency by rubber coating of polyvinyl fluoride (PVC). At the same time, the first joint <NUM> includes a notch in fluid communication with the air inlet outer cover <NUM> to facilitate air circulation, as shown in <FIG>. Similarly, the second joint <NUM> connected to the air inlet passage <NUM> may also be mounted to the inner wall of the pool by a rubber coating, and fixedly connected to the first installation port <NUM> of the shell <NUM> by screws. The second joint <NUM> includes a notch in fluid communication with the internal cavity of the shell <NUM>. The notches and the connection interface shown in the figures are merely examples, and a variety of other configurations may be used to perform the same function.

In various embodiments, and as shown in <FIG>, the shell 501a, 501b of the air outlet assembly <NUM> may comprise a first shell 501a and a second shell 501b connected to each other so that the first installation port <NUM> and the second installation port <NUM> are formed on the first shell 501a and/or the second shell 501b, and the first installation port <NUM> and the second installation port <NUM> each include air holes in fluid communication with the internal cavity. Alternatively, the first installation port <NUM> may be formed on the second shell 501b, and/or the second installation port <NUM> may be formed on the first shell 501a. In addition, a structural feature matching the first installation port <NUM> may be formed on the first shell 501a, so that the shell 501a, 501b can be fixedly connected to the second joint <NUM>, for example, by screws. Such a connection may also attach the shell 501a, 501b with the inner wall of the pool. As shown in <FIG>, the annular wall of the second shell 501b extends axially toward the internal cavity and is perforated to form the first air holes <NUM> at a position adjacent to the first installation port <NUM>. As also shown in <FIG>, the first shell 501a extends axially toward the internal cavity to form the recessed portion, and the annular wall of the recessed portion is perforated to form the second air holes <NUM> at a position adjacent to the second installation port <NUM>. Thus, the first air holes <NUM> and the second air holes <NUM> allow air to circulate out of the internal cavity. Of course, the structure of the shell 501a, 501b in this embodiment is merely exemplary.

After the air inlet assembly, the air outlet assembly and the water outlet assembly are assembled, they may be interconnected, as shown in <FIG>. When in normal use, water flow in the pool <NUM> enters the water outlet pipe <NUM> from the water outlet device <NUM>, and then returns to the pool through the pump <NUM>, the water inlet pipe <NUM>, and the water inlet device <NUM>.

If only the water outlet orifices of the water outlet device <NUM> are blocked, as shown in <FIG>, a gap is formed between the outer circumference of the water outlet device <NUM> and the inner circumference of the recessed portion of the shell <NUM>. This gap provides for fluid communication between the through holes <NUM> in the circumferential side wall of the water outlet device and the pool, and water flow can continue to flow from the through holes <NUM> to the water outlet pipe <NUM> and return to the pool through the pump <NUM>, the water inlet pipe <NUM>, and the water inlet device <NUM>. Such a partial blockage may be caused, for example, by hair, objects, clothes, or other obstructions <NUM>. At this time, although the inlet water flow of the pump may be affected, the through holes <NUM> of the water outlet device can still be used as water outlet orifices. If the gap between the outer circumference of the water outlet device and the inner circumference of the recessed portion is very small, the fluid inside of the air outlet assembly may partially flow into the through holes <NUM> of the water outlet device through the second air holes <NUM>.

When the water outlet device is completely blocked by the obstruction <NUM>, for example, when the water outlet device is blocked by a portion of a user's body, the gap between the outer circumference of the water outlet device and the inner circumference of the recessed portion is also blocked, as shown in <FIG>. In this case, water cannot flow in smoothly from the water outlet device <NUM>; the water outlet device <NUM> and the shell <NUM> form a relatively closed space; and the through holes <NUM> of the water outlet device are in fluid communication with the second air holes <NUM> of the shell <NUM>. The pump continues to operate, drawing air from the air inlet outer cover <NUM>. Air enters the internal cavity of the shell <NUM> via the air inlet passage <NUM> and the first air holes <NUM> of the shell <NUM>, flows out from the second air holes <NUM> of the shell <NUM>, enters the water outlet device <NUM> via the through holes <NUM> of the water outlet device, passes through the water outlet pipe <NUM>, the pump <NUM>, the water inlet pipe <NUM> and the water inlet device <NUM>, returning to the pool and the outside (atmosphere). At this time, the through holes <NUM> of the water outlet device are completely used as air inlets. The air in the fluid path continues to circulate, and the negative pressure at the water outlet device is reduced, allowing a portion of a user's body to more easily escape from the water outlet, reducing the risk of injury.

<FIG> show a water circulation system for a pool according to a sixth embodiment. This sixth embodiment is different from the fifth embodiment of <FIG> in that the air inlet outer cover <NUM> of the air inlet assembly <NUM> is mounted to the outer wall <NUM> of the pool. In this way, the air inlets of the air inlet outer cover <NUM> are kept unblocked, and also the inner wall of the pool is simplified, thereby increasing the usable area of the pool and improving the user experience. In the illustrated embodiment, the air inlet outer cover <NUM> is located at the upper part of the outer wall <NUM>. Since the air inlets are continuously unblocked, in an alternative embodiment, the position of the air inlet outer cover <NUM> on the outer wall <NUM> is not limited, for example, it could be located at the middle, lower, or other parts of the outer wall <NUM>.

<FIG> show a water circulation system for a pool according to a seventh embodiment. This seventh embodiment is different from the fifth embodiment of <FIG> in that the air inlet outer cover <NUM> of the air inlet assembly <NUM> is mounted to a top wall <NUM> of the pool. Such an arrangement also helps to keep the air inlets of the air inlet outer cover <NUM> continuously unblocked, thus improving the user experience.

<FIG> show a water circulation system according to an eighth embodiment. This eighth embodiment is different from the fifth embodiment of <FIG> in that the air inlet passage <NUM> is arranged in a pool body of the pool <NUM> and adjacent to the inner wall <NUM> of the pool. The term, "pool body," means an interior space of the pool for containing water. Compared with the air inlet passage formed through the internal cavity of the shell <NUM> in the above embodiment, the air inlet passage <NUM> may be in the form of a flexible hose that is easy to bend and will not produce adverse effects on the user. Compared with the air inlet passage arranged, for example, in the inflatable chamber of the pool in the above embodiment, the air inlet passage of this embodiment is easier to maintain and replace.

Thus, when the filter <NUM> is not connected to the water outlet assembly <NUM>, as shown in <FIG>, part of the fluid flow (including air and/or water) enters the shell <NUM> from the air inlets <NUM> of the air inlet outer cover <NUM> along the air inlet passage <NUM>, as indicated by the depicted arrows, and then enters the water outlet pipe <NUM> from the shell <NUM> via the through holes <NUM> of the water outlet device <NUM>. At the same time, the other part of the fluid flow enters the water outlet pipe <NUM> through the water outlet orifices <NUM> of the water outlet device <NUM>. After the filter <NUM> is installed to the water outlet assembly <NUM>, as shown in <FIG>, the connection interface <NUM> of the filter <NUM> abuts against the base <NUM>, urging the base <NUM> to move towards the water outlet pipe <NUM> and then squeezing the elastic member <NUM>, causing the base <NUM> to block the through holes <NUM> in the side wall of the water outlet device <NUM>. Water flows in from the filter ports <NUM> of the filter <NUM>, as indicated by the depicted arrows, and then returns to the pool via the water outlet pipe <NUM>, the pump <NUM>, the water inlet pipe <NUM> and the water inlet device <NUM>.

<FIG> show a water circulation system according to a ninth embodiment. This ninth embodiment is different from the eighth embodiment of <FIG> in that the water outlet device <NUM> does not include an elastic member or a base. Similar to the fourth embodiment, as shown in <FIG>, the shell of the water outlet assembly includes an annular wall <NUM> extending axially toward the inside of the internal cavity, and an opening <NUM> formed on the annular wall <NUM>. Thus, when the filter <NUM> is connected to the water outlet device <NUM> of the water outlet assembly, the connection interface <NUM> of the filter <NUM> serves as a water flow blocking member to block the through holes <NUM>, and thus, as shown in <FIG> and <FIG>, water flow can only flow into the water outlet pipe <NUM> from the filter ports <NUM> of the filter <NUM>, as indicated by the depicted arrows.

Regardless of the implementation details, the water circulation system for a pool according to the present disclosure can reliably circulate and filter water in the pool and ensure the personal safety of users. Unless otherwise defined, the term "flexible" means providing for some relative motion between components. The components and features described herein may be made of various materials that include, but are not limited to, any suitable materials, such as polymers, rubber, foam and metal, or combinations of materials, which may be known to those skilled in the art.

It should be understood that the embodiments as shown in the drawings only show exemplary shapes, sizes and arrangements of optional components of the water circulation system for a pool, which are merely illustrative but not restrictive, and other shapes, sizes and arrangements may be employed without departing from the idea and scope of the present disclosure.

Claim 1:
A water circulation system for a pool, comprising:
a water outlet assembly (<NUM>) mounted to an inner wall (<NUM>) of the pool (<NUM>) and in fluid communication with an external pump (<NUM>) through a water outlet pipe (<NUM>), said external pump (<NUM>) drawing water out of the pool through the water outlet assembly (<NUM>);
an air inlet assembly (<NUM>, <NUM>) mounted to the pool at a preset distance from the water outlet assembly (<NUM>);
an air outlet assembly (<NUM>, <NUM>) attached to the water outlet assembly (<NUM>) and in fluid communication with the water outlet assembly (<NUM>); and
an air inlet passage (<NUM>, <NUM>) connecting the air inlet assembly (<NUM>, <NUM>) to the air outlet assembly (<NUM>, <NUM>), wherein fluid can enter the air inlet assembly (<NUM>, <NUM>) and be introduced to the water outlet assembly (<NUM>) through the air outlet assembly (<NUM>, <NUM>) when the water outlet assembly (<NUM>) is blocked.