Electric switching device
First Claim
1. An electric switching device, comprising:
- a housing;
a main contact assembly including two fixed contacts, each formed as a pin and positioned along a common center line axis and each said pin including a confronting plane surface directed to form a wedge-shaped opening, and one movable contact including two plane contact wedge-shaped surfaces conforming to the wedge-shaped opening each of said fixed contacts, said movable contact being movable between a closed position to close an electrical circuit, in which said two fixed contacts are connected, and an open position to open said electrical circuit, in which said two fixed contacts are disconnected, said main contact assembly being disposed in a first cavity in said housing;
a piston shaft axially movable along an axis perpendicular to said common center line axis, a first end of said shaft carrying said movable contact in said first cavity, a second end of said piston shaft positioned in a second cavity in said housing, said first cavity and second cavity being interconnected through a channel in said housing, said piston shaft carrying a piston with first and second piston cavities on each end thereof;
an auxiliary contact mechanism connected to said main contact assembly and including two movable hollow contact pins for closing and opening said electrical circuit later than the respective closing and opening of said electrical circuit by operation of said main contact assembly;
a hydraulic system interconnected with said first cavity and said second cavity for operating said movable contact mechanism and said auxiliary contact mechanism; and
two bistable mechanisms disposed in said second cavity and including at least one piston biased by means of a spring for locking said piston shaft with said movable contact in said open and closed positions in which said movable contact is positioned with a pressure drop in the hydraulic system.
1 Assignment
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Accused Products
Abstract
An electric switching device according to the invention comprises two fixed contacts and one movable contact, referred to jointly as the main contact system. The main contact system is located in an oil-insulated cavity enclosed in a housing. In its direction of movement, the movable contact has an extension in the form of a shaft. The shaft is formed with a hydraulic piston by which the movable contact is operated. The hydraulic piston is surrounded by a cavity in which a piston cavity is formed on each side of the hydraulic piston. The piston cavities are oil-filled. The movement of the shaft is determined by an electrically controlled directional valve. The directional valve receives signals as to whether the electric switching device is to be opened or closed. At a given signal, the directional valve distributes a high pressure to the piston cavity that is to be enlarged. The electric switching device can be provided with an auxiliary contact mechanism which can be placed either in the fixed contacts and/or in the movable contact. The electric switching device is provided with a bistable mechanism comprising wedge-shaped pistons biased by means of springs. The wedge-shaped pistons, in case of drop-out of pressure, lock the movable contact in the existing position via the shaft.
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Citations
10 Claims
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1. An electric switching device, comprising:
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a housing; a main contact assembly including two fixed contacts, each formed as a pin and positioned along a common center line axis and each said pin including a confronting plane surface directed to form a wedge-shaped opening, and one movable contact including two plane contact wedge-shaped surfaces conforming to the wedge-shaped opening each of said fixed contacts, said movable contact being movable between a closed position to close an electrical circuit, in which said two fixed contacts are connected, and an open position to open said electrical circuit, in which said two fixed contacts are disconnected, said main contact assembly being disposed in a first cavity in said housing; a piston shaft axially movable along an axis perpendicular to said common center line axis, a first end of said shaft carrying said movable contact in said first cavity, a second end of said piston shaft positioned in a second cavity in said housing, said first cavity and second cavity being interconnected through a channel in said housing, said piston shaft carrying a piston with first and second piston cavities on each end thereof; an auxiliary contact mechanism connected to said main contact assembly and including two movable hollow contact pins for closing and opening said electrical circuit later than the respective closing and opening of said electrical circuit by operation of said main contact assembly; a hydraulic system interconnected with said first cavity and said second cavity for operating said movable contact mechanism and said auxiliary contact mechanism; and two bistable mechanisms disposed in said second cavity and including at least one piston biased by means of a spring for locking said piston shaft with said movable contact in said open and closed positions in which said movable contact is positioned with a pressure drop in the hydraulic system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification