Hitachi, Ltd.

Yoshio Yoshioka

Kunio Hirasawa

Masanori Tsukushi

Osamu Koyanagi

Motoo Yamaguchi

Katsuichi Kashimura

Ken-ichi Natsui

Shunji Tokuyama

Fumihiro Endo

Hiroshi Suzuki

Mikio Sato

Kouji Kuwabara

Isao Takahashi

Akio Nishikawa

Makoto Yano

Kiyoshi Okumura

Keiji Arimatsu

Minoru Fujimoto

Tsutomu Tsukui

Toshio Shimizu

Minoru Sato

Ryota Doi

Takanori Satoo

Yukio Nakagawa

Masao Hosokawa

Kiyoshi Saito

Takanao Kurasawa

Shigeo Kobayashi

Isamu Sone

Hiroshi Chida

Kooji Suzuki

A light beam (30) including a random polarization and radiated from a light source, such as laser oscillator (6) is separated into P wave polarization light beam and S wave polarization light beam by a beam splitter 33. After modulated by image information representative of characters to be printed, both the P and S wave polarization beams are merged and the resultant light beam is projected on the surface of a workpiece for marking a pattern.

Apparatus for reducing, enlarging and projecting image information

A protrusion is formed downstream of the throat of an insulating nozzle of a gas-insulated circuit breaker of puffer type. Quenching gas, after collision with the protrusion, is blown against an arc generated between a fixed arcing contact and a moving arcing contact in the opening process of the gas-insulated circuit breaker. As a result, a pressure drop at or near the forward end (Q) of the fixed arcing contact can be prevented thereby to improve the insulation strength in the opening process.

Gas-insulated circuit breaker

A fuel cell made up of a pile of unit cells, each consisting of a pair of cell element and separator packed in a cell frame, in which there are formed a fuel feed path and oxide product evacuation path in the piling direction. The cell frame is provided between its inner edge offsets and the outer edges of the cell element and separator with inner packings, and further provided near its outer edge on one side with an outer packing. The sealing structure perfectly prevents a fuel leak, and yet allows compactness and easy assembling process.

Fuel cell

There is disclosed a high-voltage DC circuit breaker apparatus with reverse current insertion system by line voltage charge, which comprises a commutation switch, a series circuit of a capacitor, a reactor and a switch connected in parallel with the commutation switch, a resistor connected so as to charge the capacitor by a line voltage. The charging time constant of the capacitor determined by the capacity of the capacitor and the resistor is used as a reference in a manner so that the rise time constant of the line voltage is smaller than the charging time constant of the capacitor, and the rise time constant of the line current is larger than the charging time constant of the capacitor, thereby interrupting the fault current without fail.

High-voltage DC circuit breaker apparatus

A SF.sub.6 gas insulating electric apparatus usable as a circuit breaker, etc., containing a SF.sub.6 gas insulator and a resin insulator, both of which insulators are present in an atmosphere to be exposed to arcs, characterized by making at least the surface portion to be exposed to arcs of the resin insulator from a polymer containing nitrogen atoms or a polyolefin resin, and if necessary together with an inorganic filler powder, is excellent in both surface and inner arc resistance and can maintain breaking performance for a long period of time.

SF.sub.6 Gas arc extinguishing electric apparatus and process for

An electromagnetic puffer type gas circuit breaker comprises two opposing puffer type gas circuit breaking units mounted on midway support means, actuating means for driving the circuit breaking units, an electromagnetic actuating unit drivingly coupled to the actuating means, and current transfer mechanism for transferring and applying the interrupting current to the electromagnetic actuating unit during a circuit breaking operation. The current transfer mechanism is located, in operative connection to the actuating means, at a point above the midway support means and in a spaced relation to the electromagnetic actuating unit. The contact surface area of the current-conducting path portion leading to the transfer mechanism is a fraction of that of another current-conducting path portion for the passage of most of the rated current. These features provide ease of inspection and replacement of the current transfer mechanism and reduces the operating force requirement of the breaker.

Electromagnetic puffer type gas circuit breaker

A puffer type gas-blast circuit breaker includes at least one interrupting unit mounted in a vessel filled with an arc-extinguishing gas of a unitary pressure. The interrupting unit comprises: a fixed contact; a movable contact movable toward and away from the fixed contact to be engaged with and to be disengaged from the fixed contact respectively, the movable contact having therein an axial hollow portion, wherein an arc is established between the contacts upon disengagement of the movable contact from the fixed contact; a compression chamber filled with an arc extinguishing gas; a suction chamber, wherein an arc extinguishing gas within the compression chamber is compressed and the volume of the suction chamber is enlarged upon movement of the movable contact away from the fixed contact, and wherein a pressure difference between the compression chamber and the suction chamber causes the arc extinguishing gas to be directed from the compression chamber through the axial hollow portion into the suction chamber thereby to be blown against an arc produced between the fixed contact and the movable contact; and means provided in the suction chamber for cooling an arc extinguishing gas introduced into the suction chamber to suppress a pressure rise within the suction chamber for maintaining a sufficiently large pressure difference between the compression chamber and the suction chamber, thereby shortening an arcing time and improving a breaking performance.

Puffer-type gas-blast circuit breaker

A puffer type gas-blast circuit breaker includes at least one interrupting unit mounted in a vessel filled with an arc-extinguishing gas of a unitary pressure. The interrupting unit comprises: a fixed contact; a movable contact movable toward and away from the fixed contact to be engaged with and to be disengaged from the fixed contact respectively, the movable contact having an axial hollow portion, wherein an arc is established between the contacts upon disengagement of the movable contact from the fixed contact; an insulating nozzle encompassing a free end portion of the movable contact and having a throat portion therein, which is substantially closed with the fixed contact; a compression chamber filled with an arc extinguishing gas; a suction chamber, wherein an arc extinguishing gas within the compression chamber is compressed and the volume of the suction chamber is enlarged upon movement of the movable contact away from the fixed contact, whereby a pressure difference between the compression chamber and the suction chamber causes the arc extinguishing gas to be directed from the compression chamber through the axial hollow portion into the suction chamber thereby to be blown against an arc produced between the fixed contact and the movable contact; and the suction chamber is brought into an open condition to or communication with a space in the vessel, simultaneously when the fixed contact is drawn out of the throat portion in the insulating nozzle.

A puffer type gas circuit breaker comprises a first and a second arcing electrodes movable relative to each other, an insulating nozzle surrounding the second arcing electrode, a puffer device for introducing an arc-suppressing gas into the insulating nozzle to puff out the arc produced between the two arcing electrodes when the breaker is in motion for circuit breaking, and a movable shield device for relieving the concentration of an electric field at the front end of the first arcing electrode during the breaker motion for circuit breaking. When the breaker is closed and the circuit made, the movable shield device surrounds the first arcing electrode and insulating nozzle, with a predetermined gap between itself and the insulating nozzle opposite thereto, and is kept at the same potential as the first arcing electrode. The circuit breaker further includes a device for maintaining the predetermined gap and the same potential at least in the early stage of the breaker motion for current breaking.

Puffer type gas circuit breaker

In a magnetic puffer type gas circuit breaker including an electromagnetic coil through which a current to be interrupted flows during the breaking operation, and an electromagnetic repulsive member which produces an electromagnetic repulsive force in cooperation with the electromagnetic coil and drives movable parts of a breaking portion of the apparatus, the electromagnetic repulsive member is so arranged that the electromagnetic neutral position of the electromagnetic repulsive member within the electromagnetic coil at the time when the breaking portion has been closed deviates on the closing side with respect to the electromagnetic center of the electromagnetic coil. Further, the characteristics of the electromagnetic repulsive forces between the electromagnetic coil and the electromagnetic repulsive member are so set that their absolute values become smaller on the closing side than on the breaking side with respect to the point at which the electromagnetic center of the electromagnetic coil and the electromagnetic neutral position of the electromagnetic repulsive member are coincident.

Magnetic puffer type gas circuit breaker

Two puffer type circuit breaking units are symmetrically disposed with respect to a bracket interposed therebetween. Linking means are mounted in the bracket, and one end of the linking means is connected to movable parts of the puffer type circuit breaking units and the other end is connected to operating means through an electrically insulated operating rod. An electromagnetic coil is disposed in the bracket and an electromagnetic repulsive member is electromagnetically connected to the electromagnetic coil to produce an electromagnetic repulsive force. During the breaking operation, current transferring means mounted in the puffer type breaking units are actuated to apply an electric current to the electromagnetic coil, and an electromagnetic repulsive force is imposed on the electromagnetic repulsive member to actuate the movable parts of the puffer type breaking units together with the operating means, whereby the breaking of a large current is made possible. Since the current transferring means are disposed in the breaking units, the structure of the current transferring means is simplified and construction thereof is facilitated and transfer of an electric current to the electromagnetic coil can be performed assuredly.

A circuit breaker comprising an interrupting unit mounted in a vessel filled with a charge of arc extinguishing gas of uniform pressure and operating such that when the circuit is broken the arc extinguishing gas is compressed to increase its pressure, so that the high pressure gas will be blown against an electric arc established between the contacts to extinguish the same. The circuit breaker is formed therein with two paths for the high pressure gas blown against the arc, each path having an insulating nozzle mounted in it.

A circuit breaker having a pair of circuit breaking units electrically insulated from ground by supporting means of electrical insulator, an actuator disposed on ground, and an actuating force transmission path including a single actuating rod of electrical insulator for connecting the actuator to the movable contacts in the circuit breaking units. In the circuit breaker, an electromagnetic actuating unit is disposed between the supporting means of electrical insulator and the circuit breaking units in electrically insulated relation from the circuit breaking units. This electromagnetic actuating unit comprises a current conducting path portion for electrically connecting the circuit breaking units in series with each other, means disposed in parallel with this current conducting path portion for producing an electromagnetic repulsive force, and means for transferring current flow to the repulsive force producing means from the current conducting path portion in response to the operation of the actuator so that the electromagnetic repulsive force produced by the repulsive force producing means can be used as an actuating force for driving the movable contacts in the circuit breaking units in the circuit breaking direction.

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Hitachi, Japan

Yoshio Yoshioka