Patent Description:
As an example, Patent Literature <NUM> discloses a wash-basin including a bowl part provided with an overflow hole, and an overflow part provided with an overflow flow path communicating with the overflow hole. The overflow part is provided at the bowl part in such a manner as to bulge at the back of the bowl part.

Patent Literature <NUM>: <CIT>
<CIT> discloses the preamble of claim <NUM>. <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT> represent related art.

The wash-basin with the overflow hole formed at the bowl part has various problems such as a problem in a hygienic aspect, a problem in an aesthetic aspect, and a problem in a manufacturing process. The problem in a hygienic aspect is caused by invasion of harmful insects through the overflow hole, for example. The problem in an aesthetic aspect is caused by the bulge of the overflow part at the back of the bowl part, for example. The problem in a manufacturing process is caused by the reason that, while a bowl with a cavity such as an overflow flow path is generally manufactured by a sludge removal manufacturing method, the sludge removal manufacturing method involves many steps and results in large weight of a wash-basin. There is another problem in that, if a wash-basin without an overflow function is already installed, trying to make a change to a wash-basin having an overflow function requires replacement of a wash-basin.

In <CIT>, the overflow valve can be accidentally opened by heavy objects in the sink or by force applied to the valve while the sink is in use.

The present disclosure is intended to provide a drain unit and a wash-basin capable of solving the various problems described above.

A drain unit according to the present disclosure comprises: a first cylindrical body to be mounted on a drain port; a second cylindrical body provided inside the first cylindrical body; and a water plug member provided inside the second cylindrical body. The water plug member is capable of closing an inside part of the second cylindrical body. A flow path is provided between the first cylindrical body and the second cylindrical body. The second cylindrical body has an opening part through which the flow path and space in the inside part of the second cylindrical body communicate with each other.

In the above-described drain unit, even if the inside part of the second cylindrical body is closed while water is supplied, the supplied water enters the flow path provided between the first cylindrical body and the second cylindrical body. The water having entered the flow path between the first cylindrical body and the second cylindrical body passes through the opening part, enters the space in the inside part of the second cylindrical body, and is discharged through the drain port. Using this drain unit can suppress overflow of water from a bowl part and eliminate the need for an overflow hole, making it possible to solve the above-described various problems. Furthermore, even a wash-basin already installed without an overflow function can be given an overflow function by only mounting the above-described drain unit on this wash-basin.

According to the claimed invention, the drain unit further comprises: a valve arranged in the flow path in such a manner as to face the opening part; and resistance means that applies resistive power to the valve toward a direction opposite to a flow path direction. Water pressure acting on the valve changes in response to the water level of water stored in a bowl. In an initial period when water supply is started, the amount of water entering the inside part of the second cylindrical body through the opening part is small so water is stored easily in the bowl part. When water is stored in the bowl part and water pressure acting on the valve becomes greater than the resistive power, the valve moves in the flow path direction. When the valve moves in the flow path direction, water enters the inside part of the second cylindrical body through the opening part from the flow path, making it possible to suppress overflow of water from the bowl part.

The resistance means may have a spring that biases the valve. With a simple configuration of only providing the spring on the side of the flow path direction relative to the valve, it is possible to apply resistive power to the valve toward a direction opposite to the flow path direction.

A wash-basin according to the present disclosure may comprise: the drain unit according to the present disclosure; and a bowl having a bottom where the drain port is provided. This makes it possible to provide a wash-basin including a bowl part where an overflow hole is not formed, so that the above-described various problems can be solved.

According to the present disclosure, it is possible to provide a drain unit and a wash-basin capable of solving the various problems described above.

An embodiment of the present disclosure will be described by referring to the drawings. In <FIG> referred to below, members common between the drawings are given the same sign. In the present description, an upward direction means an upward direction on the planes of the drawings, and a downward direction means a downward direction on the planes of the drawings.

<FIG> is a schematic view showing a wash-basin <NUM> of the present disclosure and the vicinity thereof. The wash-basin <NUM> includes a wash bowl <NUM> and a drain unit <NUM>. The wash bowl <NUM> has a drain port <NUM> provided at a bottom thereof. The drain unit <NUM> is mounted on the drain port <NUM> of the wash bowl <NUM>. When a spout handle <NUM> is operated, water is supplied from a spout pipe <NUM>. The supplied water is discharged through the drain port <NUM> on which the drain unit <NUM> is mounted.

By referring to <FIG>, various members belonging to the drain unit <NUM> of the present disclosure will be described first in terms of their shapes, etc. <FIG> is an exploded perspective view showing an example of the drain unit <NUM> of the present disclosure.

The drain unit <NUM> includes at least a first cylindrical body <NUM>, a second cylindrical body <NUM>, and a water plug member <NUM>. In the present embodiment, the second cylindrical body <NUM> and the water plug member <NUM> are configured as separate bodies. Alternatively, the second cylindrical body <NUM> and the water plug member <NUM> may be integrated with each other.

The first cylindrical body <NUM> is a circular cylindrical member made of stainless steel, for example. The first cylindrical body <NUM> has a diameter slightly less than that of the drain port <NUM> (see <FIG>). The first cylindrical body <NUM> has a first flange part <NUM> extending in a peripheral direction and provided at an upper end portion of the first cylindrical body <NUM> in a circular cylindrical axis direction.

The second cylindrical body <NUM> is a circular cylindrical member made of stainless steel, for example, and is fitted to the inside of the first cylindrical body <NUM>. The second cylindrical body <NUM> has a second flange part <NUM> extending in a peripheral direction and provided at an upper end portion of the second cylindrical body <NUM> in a circular cylindrical axis direction. The second cylindrical body <NUM> has an opening part <NUM> formed at a circular cylindrical section of the second cylindrical body <NUM>. In the present embodiment, the second cylindrical body <NUM> has two opening parts <NUM> arranged in a peripheral direction of the circular cylindrical section. However, the number of the opening parts <NUM> is not limited to two.

The water plug member <NUM> has a drain plug <NUM>, a shaft part <NUM>, and a catcher <NUM>. The drain plug <NUM> is a member of a circular plate shape made of stainless steel, for example. The drain plug <NUM> can close a radially inside part of the second cylindrical body <NUM> by closing an opening <NUM> of the second cylindrical body <NUM> at one of the end portions of the second cylindrical body <NUM> in the circular cylindrical axis direction. The drain plug <NUM> has a fitting (not shown in the drawings) provided at the center of a lower surface thereof for fitting the shaft part <NUM>.

The shaft part <NUM> is a member of a straight rod shape made of stainless steel, for example. The shaft part <NUM> has an upper end portion that is fitted to the fitting of the drain plug <NUM> in such a manner as to be perpendicular to the drain plug <NUM>. The shaft part <NUM> is movable in an up-down direction by a mechanism not shown in the drawings abutting on a lower end portion of the shaft part <NUM>. In response to the movement of the shaft part <NUM> in the up-down direction, the water plug member <NUM> entirely moves in the up-down direction.

The catcher <NUM> is a circular member centered at the shaft part <NUM> and made of resin, for example. The catcher <NUM> has a large number of holes in order to suppress flowing out of hair, dust, etc. into a drain pipe <NUM> (see <FIG> referred to later). The catcher <NUM> is movable up and down while an outer peripheral surface of the catcher <NUM> and an inner peripheral surface of the second cylindrical body <NUM> abut on each other so as to prevent hair, dust, etc. from flowing out from between the outer peripheral surface of the catcher <NUM> and the inner peripheral surface of the second cylindrical body <NUM>.

The drain unit <NUM> is mounted on the drain port <NUM> while the second cylindrical body <NUM> is fitted to the inside of the first cylindrical body <NUM> and the water plug member <NUM> is arranged in the radially inside part of the second cylindrical body <NUM>. As long as the drain unit <NUM> can be mounted on the drain port <NUM>, the mounting is not limited to a particular procedure. As an example, the procedure may be such that, after the first cylindrical body <NUM> is mounted on the drain port <NUM> of the wash bowl <NUM>, the second cylindrical body <NUM> is fitted to the inside of the first cylindrical body <NUM> and the water plug member <NUM> is arranged in the radially inside part of the second cylindrical body <NUM>. The procedure may also be such that, after the first cylindrical body <NUM> with the second cylindrical body <NUM> fitted therein is mounted on the drain port <NUM> of the wash bowl <NUM>, the water plug member <NUM> is arranged in the radially inside part of the second cylindrical body <NUM>. Either mounting procedure allows the drain unit <NUM> to be mounted easily on the drain port <NUM>.

The drain unit <NUM> further includes a valve <NUM> and resistance means <NUM>. In the present embodiment, the valve <NUM> and the resistance means <NUM> are provided in a radially inside part of the first cylindrical body <NUM> and a radially outside part of the second cylindrical body <NUM>.

The valve <NUM> is a circular cylindrical member made of stainless steel, for example. The resistance means <NUM> is provided under the valve <NUM> and biases the valve <NUM> upward. The resistance means <NUM> is a spring, for example. In the present embodiment, a coil spring is employed as the resistance means <NUM>.

The first cylindrical body <NUM>, the second cylindrical body <NUM>, the drain plug <NUM>, the shaft part <NUM>, and the valve <NUM> are not limited to members made of stainless steel but may be made of other types of metal or resin, for example. Likewise, the catcher <NUM> is not limited to a member made of resin but may be made of metal such as stainless steel. Note that each of the first cylindrical body <NUM>, the second cylindrical body <NUM>, the drain plug <NUM>, the shaft part <NUM>, the valve <NUM>, and the catcher <NUM> is preferably made of a material resistant to corrosion with good maintainability, for example.

Even if the drain unit <NUM> includes the valve <NUM> and the resistance means <NUM>, mounting of the drain unit <NUM> on the drain port <NUM> is not limited to a particular mounting procedure.

Operation of the drain unit <NUM> of the present disclosure will be described next by referring to <FIG> is a longitudinal sectional view showing an example of a case where the drain unit <NUM> is mounted on the drain port <NUM> of the wash bowl <NUM>. <FIG> is a partial longitudinal sectional view showing the water plug member <NUM> in a side view, not in a sectional view. In <FIG>, the water plug member <NUM> is movable between a first position indicated by alternate long and two short dashes lines and a second position indicated by solid lines.

The wash bowl <NUM> is arranged in such a manner as to form communication of the drain port <NUM> with the drain pipe <NUM>. When the drain unit <NUM> is mounted on the drain port <NUM> of the wash bowl <NUM>, the opening <NUM> of the second cylindrical body <NUM> and the drain pipe <NUM> communicate with each other. Water entering from the opening <NUM> of the second cylindrical body <NUM> passes through space in the radially inside part of the second cylindrical body <NUM> and is then discharged to the drain pipe <NUM>. While the drain unit <NUM> is mounted on the drain port <NUM>, the first flange part <NUM> and the drain port <NUM> are closed relative to each other.

While the drain unit <NUM> is mounted on the drain port <NUM>, a clearance is formed between the first cylindrical body <NUM> and the second cylindrical body <NUM>. This clearance forms a flow path <NUM> for allowing entry of water. A clearance between the first flange part <NUM> and the second flange part <NUM> is an inlet <NUM> to the flow path <NUM>. The valve <NUM> and the resistance means <NUM> are arranged in this flow path <NUM>.

Operation of the drain unit <NUM> fulfilled by the provision of the first cylindrical body <NUM>, the second cylindrical body <NUM>, and the water plug member <NUM> will be described first. Further operation of the drain unit <NUM> fulfilled by the provision of the valve <NUM> and the resistance means <NUM> will be described next.

As described above, the water plug member <NUM> entirely moves in the up-down direction when the shaft part <NUM> moves in the up-down direction. Meanwhile, the first cylindrical body <NUM>, the second cylindrical body <NUM>, the valve <NUM>, and the resistance means <NUM> do not move in response to the movement of the water plug member <NUM> in the up-down direction.

When the water plug member <NUM> moves upward, the opening <NUM> of the second cylindrical body <NUM> becomes opened. The opening <NUM> is opened at the above-described first position. When the opening <NUM> is opened, water supplied from the spout pipe <NUM> (see <FIG>) passes through the opening <NUM> and is then discharged to the drain pipe <NUM> except water flowing into the flow path <NUM>. The amount of water to be discharged to the drain pipe <NUM> through the opening <NUM> while the opening <NUM> is opened differs in response to a place of installation. Preferably, this amount is greater than the amount of water to be supplied from the spout pipe <NUM>. The amount of water to be supplied from the spout pipe <NUM> can be a maximum amount of water to be supplied or can be the amount of water to be supplied that is determined on the basis of a predetermined design standard.

When the water plug member <NUM> moves downward to reach the above-described second position, the opening <NUM> is blocked by the drain plug <NUM> and is closed. When the opening <NUM> is closed, supplied water is stored in the wash bowl <NUM>.

The inlet <NUM> to the flow path <NUM> is always opened. Even if the opening <NUM> is closed, supplied water still enters the flow path <NUM>. The flow path <NUM> and the space in the radially inside part of the second cylindrical body <NUM> communicate with each other through the opening part <NUM>. Water having entered the flow path <NUM> flows into the space in the radially inside part of the second cylindrical body <NUM> through the opening part <NUM>. The space in the radially inside part of the second cylindrical body <NUM> communicates with the drain pipe <NUM>. Water having flowed into the space in the radially inside part of the second cylindrical body <NUM> is discharged to the drain pipe <NUM>. The amount of water to enter the flow path <NUM> and to be discharged while the opening <NUM> is closed is less than the amount of water to be supplied (for example, a maximum amount of water to be supplied) responsive to a place of installation.

In the drain unit <NUM> of the present disclosure, closing the opening <NUM> allows supplied water to be stored in the wash bowl <NUM>. Even when the opening <NUM> is closed, supplied water still enters the flow path <NUM> and is discharged. Thus, it is possible to suppress overflow of water from the wash bowl <NUM> even without provision of an overflow hole at the wash bowl <NUM>.

The presence of an overflow hole at a wash bowl causes a risk of invasion of harmful insects through the overflow hole, so that room is left for improvement in a hygienic aspect. Moreover, the wash bowl with the overflow hole has a bulge at its back in order to assure a flow path for water entering through the overflow hole, resulting in poor aesthetic property. As aesthetic property is required particularly in the case of a vessel type, a bulge at the back of the wash bowl is preferred. Furthermore, while the wash bowl with the overflow hole is generally manufactured by a sludge removal manufacturing method, the manufacture has difficulty as the sludge removal manufacturing method involves many steps and results in large weight of a wash-basin. Mounting the drain unit <NUM> of the present disclosure on a drain port of the wash bowl eliminates the need to provide the overflow hole at the wash bowl. As a result, the various problems relating to a wash-basin with the overflow hole at the wash bowl are solved. As the drain unit <NUM> can easily be mounted on the drain port <NUM> of the wash bowl <NUM> as described above, excellent maintainability is provided and cleanliness can be kept. In particular, as the wash bowl does not have a bulge at its back in the absence of an overflow hole at the wash bowl, aesthetic property is not damaged even in the case of a vessel type.

If a wash-basin without an overflow function is already installed, for example, trying to make a change to a wash-basin having an overflow function requires replacement of a wash-basin. In this regard, the drain unit <NUM> of the present disclosure has a simple configuration of only being mounted on the drain port <NUM> and can easily take the place of a drain unit mounted on a wash-basin already installed. As a result, it is possible to change a wash-basin without an overflow function to a wash-basin with an overflow function without the need of replacing a wash-basin.

The amount of water to enter the flow path <NUM> and to be discharged is determined on the basis of the size of the clearance between the first cylindrical body <NUM> and the second cylindrical body <NUM>, the number of the opening parts <NUM>, the size of the opening part <NUM>, etc. The amount of water to enter the flow path <NUM> and to be discharged while the opening <NUM> is closed is determined in response to the amount of water to be supplied from the spout pipe <NUM>. For this reason, the size of the clearance between the first cylindrical body <NUM> and the second cylindrical body <NUM>, the number of the opening parts <NUM>, and the size of the opening part <NUM> are determined in response to the amount of water to be supplied responsive to a place of installation.

Further operation of the drain unit <NUM> fulfilled by the provision of the valve <NUM> and the resistance means <NUM> will be described next.

As described above, the resistance means <NUM> biases the valve <NUM> upward. A coil spring as the resistance means <NUM> is arranged under the valve <NUM> in series with a direction of water flowing in the flow path <NUM>. A direction of biasing the valve <NUM> by the resistance means <NUM> is opposite to the direction of water flowing in the flow path <NUM>.

While water is not stored in the wash bowl <NUM>, the valve <NUM> faces the opening part <NUM> of the second cylindrical body <NUM> in such a manner as to close the opening part <NUM> entirely. When the valve <NUM> faces the opening part <NUM> in such a manner as to close the opening part <NUM> entirely, flow of water from the flow path <NUM> toward the space in the radially inside part of the second cylindrical body <NUM> is restricted. The restriction on the flow of water from the flow path <NUM> toward the space in the radially inside part of the second cylindrical body <NUM> makes it unlikely that flow of water will be generated in the flow path <NUM>. This results in a state where water is stored in the flow path <NUM>, so that water is stored easily in the wash bowl <NUM>.

When water is stored in the wash bowl <NUM> while the opening <NUM> of the second cylindrical body <NUM> is closed, downward load acts on the valve <NUM>. This load can be reworded as water pressure. In response to the level of water pressure acting downward on the valve <NUM>, the valve <NUM> moves downward, which is a direction in which water flows in the flow path <NUM>. When the valve <NUM> moves downward, an opening area of the opening part <NUM> is increased in response to the amount of downward movement of the valve <NUM>. When the opening part <NUM> is opened, water in the flow path <NUM> passes through the opening part <NUM>, flows into the radially inside part of the second cylindrical body <NUM>, and is then discharged to the drain pipe <NUM>.

Water pressure acting on the valve <NUM> changes in response to the water level of water stored in the wash bowl <NUM>. In an initial period when storing of water in the wash bowl <NUM> is started, a water level is low to result in low water pressure acting on the valve <NUM> and a small opening area of the opening part <NUM>. The small opening area of the opening part <NUM> reduces the amount of water flowing in the flow path <NUM>, so that water is stored in the wash bowl <NUM> easily. When the water level of water stored in the wash bowl <NUM> becomes higher, water pressure acting on the valve <NUM> is increased to increase an opening area of the opening part <NUM>. The increase in opening area of the opening part <NUM> increases the amount of water flowing in the flow path <NUM>.

In the drain unit <NUM> of the present disclosure including the valve <NUM> and the resistance means <NUM>, in an initial period when the opening <NUM> of the second cylindrical body <NUM> is closed and water supply is started, water is unlikely to flow in the flow path <NUM> so water is stored easily in the wash bowl <NUM>. When the water level of water stored in the wash bowl <NUM> becomes higher, the amount of water flowing in the flow path <NUM> is increased. Thus, even when the opening <NUM> of the second cylindrical body <NUM> is closed, it is still possible to suppress overflow of water from the wash bowl <NUM>.

As described above, in the drain unit <NUM> of the present disclosure, a coil spring is employed as the resistance means <NUM>. For the reason that the valve <NUM> is a circular cylindrical member, it is possible to bias the valve <NUM> in the upward direction by a simple configuration of only arranging the coil spring as the resistance means <NUM> under the valve <NUM>.

In the drain unit <NUM> of the present disclosure, a coil spring is employed as the resistance means <NUM>. Meanwhile, as long as the resistance means <NUM> has a function of biasing the valve <NUM>, the resistance means <NUM> is not limited to a coil spring. Furthermore, it is sufficient for the resistance means <NUM> to apply force on the valve <NUM> acting in a direction opposite to the direction of water flowing in the flow path <NUM>, namely, acting in a direction against water pressure. For example, a coil spring may be provided on upper side the valve <NUM> and the valve <NUM> may be pulled (biased) upward. In another case, the drain unit <NUM> may include a pressure sensor that detects water pressure acting downward on the valve <NUM>, and a mechanism and a controller that move the valve <NUM> in response to the water pressure detected by the pressure sensor.

While the valve <NUM> and the resistance means <NUM> are arranged in the flow path <NUM> in the drain unit <NUM> of the present disclosure, the valve <NUM> and the resistance means <NUM> are not limited to these arrangements in the flow path <NUM>. It is sufficient for the valve <NUM> to be movable between a position of closing the opening part <NUM> and a position of opening the opening part <NUM> in response to water pressure generated in the flow path <NUM>. As an example, if a section to receive water pressure is arranged in the flow path <NUM> and if this section to receive water pressure is formed integrally with the valve <NUM>, the valve <NUM> and the resistance means <NUM> can be arranged, for example, in the space in the radially inside part of the second cylindrical body <NUM>.

Claim 1:
A drain unit (<NUM>) comprising:
a first cylindrical body (<NUM>) to be mounted on a drain port (<NUM>);
a second cylindrical body (<NUM>) provided inside the first cylindrical body (<NUM>); and
a water plug member (<NUM>) provided inside the second cylindrical body (<NUM>),
wherein
the water plug member (<NUM>) is capable of closing an inside part of the second cylindrical body (<NUM>),
a flow path (<NUM>) is provided between the first cylindrical body (<NUM>) and the second cylindrical body (<NUM>), and
the second cylindrical body (<NUM>) has an opening part (<NUM>) through which the flow path (<NUM>) and space in the inside part of the second cylindrical body (<NUM>) communicate with each other,
characterized by further comprising:
a valve (<NUM>) arranged in the flow path (<NUM>) in such a manner as to face the opening part (<NUM>); and
resistance means (<NUM>) that applies resistive power to the valve (<NUM>) toward a direction opposite to a flow path direction.