# US 2011/0290343 A1 · Opening/closing device

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- Number: US 2011/0290343 A1
- Document ID: US20110290343A1
- Status: Published application
- Kind: A1
- Application number: 13/147,343
- Filed: 2010-02-02
- Published: 2011-12-01
- Earliest claimed: 2009-02-04
- Assignees: Nippon Koei Co., Ltd.; Kansei Corporation; Tokyo Metropolitan Sewerage Service Corporation
- Inventors: Hiroshi Komatsu; Motonobu Ito; Kazuhiro Yamanouchi; Kenji Hasegawa; Iwao Ito
- Web page: https://patentgrep.com/patent/US20110290343A1

## CPC

- E03F 9/007: {Devices providing a flushing surge}
- Y10T 137/7287: Liquid level responsive or maintaining systems
- Y10T 137/7404: Plural floats
- E03F: SEWERS; CESSPOOLS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An opening/closing device 1 according to the present invention includes a gate 10 that receives a flow of a sewage W in an upright state, and can fall toward a downstream side of the flow and a first spring 52a that generates a force for bringing the gate 10 into an upright state, wherein the first spring 52 generates a force insufficient for bringing the gate 10 into the upright state if the gate 10 is in a fallen state, and generates a force sufficient for bringing the gate into the upright state if the gate 10 is tilted by an angle equal to or less than a predetermined angle.

## Claims

### Claim 1

An opening/closing device comprising:
a gate that receives a flow of a fluid in an upright state, and can fall toward a downstream side of the flow; and
a first force generation unit that generates a force for bringing the gate into the upright state,
wherein the first force generation unit generates a force insufficient for bringing the gate into the upright state if the gate is in a fallen state, and generates a force sufficient for bringing the gate into the upright state if the gate is in a state tilted by an angle equal to or less than a predetermined angle.

### Claim 2 (depends on 1)

The opening/closing device according to claim 1, wherein:
the gate can fall about a gate rotation shaft;
one end of the first force generation unit is fixed above the gate rotation shaft;
the other end of the first force generation unit is arranged at a position separated by a predetermined length from the gate rotation shaft; and
a distance between a line connecting between the one end of the first force generation unit and the other end of the first force generation unit and a center of rotation of the gate rotation shaft if the gate is in the fallen state is shorter than a distance between a line connecting between the one end of the first force generation unit and the other end of the first force generation unit and the center of rotation of the gate rotation shaft if the gate is in a state tilted by an angle equal to or less than the predetermined angle.

### Claim 3 (depends on 2)

The opening/closing device according to claim 2, wherein the first force generation unit includes a spring fixed to the one end of the first force generation unit.

### Claim 4 (depends on 3)

The opening/closing device according to claim 3, wherein the first force generation unit includes a link fixed to the other end of the first force generation unit, and coupled to the spring.

### Claim 5 (depends on 1)

The opening/closing device according to claim 1, comprising a second force generation unit that generates a force sufficient for starting to bring the gate into the upright state if the gate is in the fallen state, and the water level of a flow passage through which the fluid flows is equal to or less than a predetermined water level.

### Claim 6 (depends on 5)

The opening/closing device according to claim 5, wherein:
the gate can fall about a gate rotation shaft;
one end of the second force generation unit is fixed above the gate rotation shaft; and
the other end of the second force generation unit is arranged at a position separated by a predetermined length from the gate rotation shaft.

### Claim 7 (depends on 6)

The opening/closing device according to claim 6, wherein the second force generation unit includes a spring fixed to one of one end of the second force generation unit and/or the other end of the second force generation unit.

### Claim 8 (depends on 7)

The opening/closing device according to claim 7, wherein:
one end of the first force generation unit is fixed above the gate rotation shaft;
the other end of the first force generation unit is arranged at a position separated by a predetermined length from the gate rotation shaft;
a distance between a line connecting between the one end of the second force generation unit and the other end of the second force generation unit and a center of rotation of the gate rotation shaft if the gate is in the fallen state is longer than a distance between a line connecting between the one end of the first force generation unit and the other end of the first force generation unit and the center of rotation of the gate rotation shaft if the gate is in the fallen state.

### Claim 9 (depends on 5)

The opening/closing device according to claim 5, wherein the spring constant of a spring of the first force generation unit is larger than the spring constant of a spring of the second force generation unit.