1. Field of the Invention
The present invention relates to an electrical circuit switching device that is configured by a circuit breaker for energizing or breaking a power supply of devices installed in a housing of a switchboard, a control board or the like, and an external operating handle for operating the circuit breaker from the outside of the housing.
2. Description of the Related Art
Devices for energizing or breaking power supplies, which are configured by circuit breakers and external operating handles, are commonly known. Japanese Patent Application Laid-Open No. 2010-102898 discloses an external operating handle device for a circuit breaker that performs switching operation to the circuit breaker from the outside of a housing door and can regulate opening/closing of the housing door. Japanese Patent Application Laid-Open No. 2000-311538 discloses a power supply switching device including a mechanism in which a housing door cannot be opened until a power supply is turned off. In addition, Japanese Patent Application Laid-Open No. 2004-265843 discloses an external operating handle device which performs switching operation to a circuit breaker from the outside of a housing door and which can close the housing door even in a tripped state.
However, the aforementioned Japanese Patent Application Laid-Open No. 2010-102898 and Japanese Patent Application Laid-Open No. 2004-265843 describe that the circuit breaker alone can energize the power supply by directly operating a coupling part of the circuit breaker, but have no description of restriction for energizing or breaking the power supply by the circuit breaker alone. Furthermore, the aforementioned Japanese Patent Application Laid-Open No. 2000-311538 has no mention of restriction for energizing or breaking the power supply by the circuit breaker alone.
As described above, with the conventional circuit breakers and the external operating handles, the circuit breaker alone can energize the power supply in the state where the housing door is opened. Alternately, the power supply can be easily energized by operating an operating part that is included in the circuit breaker and can energize the power supply, by hand, or by operating a portion coupled with the external operating handle, by hand. In such a manner, if the power supply can be energized in the state where the housing door is opened, an operator is at risk of mistakenly touching energized parts of devices installed in the housing. In addition, if the devices continue operating while the housing door is opened, the devices are kept exposed to the open air, which can cause failure of the devices, affecting their reliability.
The present invention thus has an object to provide an electrical circuit switching device that can energize a power supply only in the state where a housing door is closed, in order to ensure safety such that an operator does not touch energized parts of devices installed in a housing.
The electrical circuit switching device according to the present invention is installed inside the housing having a housing door, and includes a circuit breaker for breaking/energizing an electrical circuit, and an external operating handle, provided on the housing door, for operating the circuit breaker. The external operating handle includes an operating part and a coupling part for interlocking with the operating part. The circuit breaker includes a circuit switching unit for switching the electrical circuit to break/energize the electrical circuit, and a switch operating unit for driving the circuit switching unit. The switch operating unit further includes a lock part that can engage/disengage with/from the coupling part of the external operating handle, and is configured such that the coupling part of the external operating handle engages with the lock part of the switching operating unit when the housing door is closed, and meanwhile, such that the coupling part of the external operating handle disengages from the lock part of the switching operating unit when the housing door is opened. Thus the electrical circuit switching device is allowed to be operated via the coupling part of the external operating handle only in the state where the lock part of the switching operating unit is engaged with the coupling part of the external operating handle.
The lock part of the switching operating unit may be configured such that engagement of the coupling part of the external operating handle with the lock part is prevented in the state where the external operating handle is positioned at an energizing position, and disengagement of the coupling part of the external operating handle from the lock part is prevented in the state where the coupling part of the external operating handle engages with the lock part.
The present invention can provide an electrical circuit switching device that ensures safety such that an operator does not touch energized parts of devices installed in a housing, and can energize a power supply only in the state where a housing door is closed.
The aforementioned and other objects and features of the present invention will be apparent from the following description of embodiments given with reference to the accompanying drawings, in which:
A housing 10 of an electrical circuit switching device for switchboard, a control board or the like includes, as illustrated in
To ensure the safety such that an operator does not touch energized parts (not illustrated) of the devices 13 installed inside the housing body 11 with his or her hand, the electrical circuit switching device needs to have a configuration in which a power supply can be energized only in the state where the housing door 12 is closed. In addition, with such a configuration, the housing door 12 is in a closed state while the power supply is energized, allowing the devices 13 inside the housing body 11 to be protected from the open air. One embodiment of the electrical circuit switching device according to the present invention includes the circuit breaker 21 installed inside the housing body 11 and the external operating handle 41 attached to the housing door 12, in order to ensure the safety such that the operator does not touch the energized parts of the devices 13 installed inside the housing body 11 with a hand thereof.
The circuit breaker 21 includes a circuit switching unit 25 for switching an electrical circuit, and a switch operating unit 26 for driving the circuit switching unit 25. By operating the switch operating unit 26 of the circuit breaker 21 with an operating part 42 (
A direction of an arrow 46 of the operating part 42 is orthogonal to that of an arrow 47 of a coupling part 45, which causes the coupling part 45 of the external operating handle 41 to be turned in a direction illustrated by the arrow 47 of
Meanwhile, when the operating part 42 illustrated in
The external operating handle 41 includes the operating part 42 (
The operating part 42 is, as illustrated in
When the housing door 12 is closed, the lock hole 23 (
Only when the circuit breaker 21 is in a broken state, the coupling part 45 (
The circuit breaker 21 alone does not include means for energizing the power supply by human's hand or tools such as a screwdriver. To bring the circuit breaker 21 into the energized state, the coupling part 45 of the external operating handle 41 needs to be coupled with the lock hole 23 so as to operate the operating part 42. Thus, the power supply cannot be energized in the state where the housing door 12 is opened.
However, to maintain the devices 13 in the housing, there are cases where the devices 13 need to be energized with power in the state where the housing door 12 is opened. When the devices 13 in the housing are maintained, a maintenance handle 50 illustrated in
The locking means 24 (
When a device (not illustrated) installed outside the housing 10 is maintained, the locking means 43 of the external operating handle 41 is used for preventing the power supply from being unintendedly energized in the maintenance operation. By locking the locking means 43 with a padlock (not illustrated), the power supply cannot be energized because the turning operation of the operating part 42 is thereby restricted. To allow an operator to check the state of the circuit breaker 21 outside the housing, the display part 44 of ON and OFF is provided on the annular wall part provided around the operating part 42 of the external operating handle 41.
Number | Date | Country | Kind |
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2013-113236 | May 2013 | JP | national |