Abstract: Disclosed is a polymeric PTC composition comprising an organic polymer and conductive particles having a melting point of not less than 2000° C. dispersed therein and a circuit protection device comprising a PTC element comprising the PTC composition which are treated with a coupling agent and at least two electrodes which are electrically connected to the PTC element. The polymeric PTC composition is used to provide a circuit protection device having excellent environmental resistance properties, which exhibits a low resistance under normal operating conditions, and protects the circuit against the over-current even under large electric current and high voltage.

Abstract: A switch which is superior in current limiting performance. The switch comprises a movable contact element having a pair of movable contacts secured thereto, a pair of fixed contacts individually secured to fixed contact elements for individually contacting with the movable contacts, an electromagnetic driving device including a movable iron core, and a first operating rod secured to the movable iron core. An electromagnet is disposed alongside the electromagnetic driving device and includes a movable iron core, and movement of the movable iron core of the electromagnet is transmitted to the movable contact element by way of a transmitting member and a second operating rod. The first and second operating rods are disposed for movement along a common axial line, and movement of the movable iron core of the electromagnetic driving device is transmitted from the first operating rod to the movable contact element either directly or by way of the second operating rod.

Abstract: A switch for as an electromagnetic contactor, a circuit breaker for wiring, an air circuit breaker and so on is provided. The switch comprises a fixed contact 8A joined to a fixed contactor 8, an movable contact 6A joined to a movable contactor 6 to face the fixed contact, a plurality of arc extinguishing metallic plates 13 arranged with predetermined distances and in parallel to the fixed contactor 8 at the side of the end portion of the movable contactor 6 and a commutation plate 15 placed at the opposite side of the fixed contactor so as to interpose the movable contactor.

Abstract: A power switch includes a fixed contact member 13 to which a fixed contact 14 is joined, a movable contact member 5 to which there is joined a movable contact 6 movable into and out of contact with the fixed contact 14 of the fixed contact member 13, a commutation electrode 3 for transferring an arc generated when the fixed contact 14 and the movable contact 6 are separated, and a grid 2 for extinguishing the arc transferred on the commutation electrode 3, the commutation electrode 3 having a recess 17 for allowing the movable contact 6 to move out of contact with the fixed contact 14 and so that the movable contact member 5 can move toward the fixed contact member 13, the commutation electrode 3 having an end extending parallel to the grid 2 and a slit 16, 19 extending continuously from the recess 17 to a portion parallel to the grid 2.

Abstract: A switch characterized by a stationary contact element joined to a stationary contact, a movable contact element joined to a movable contact in a facing relationship to said stationary contact element, a first metallic arc extinguishing plate formed of a U-shaped vertical wall and disposed with its open end facing toward a tip of said stationary contact and which surround said stationary contact element, and a second metallic arc extinguishing plate disposed in parallel to and at the remote side from said contact elements of said first metallic arc extinguishing plate, said first metallic arc extinguishing plates being disposed at predetermined gaps relative to said stationary contact.

Abstract: A power switch includes a fixed contact member 8 having a fixed contact 8A, a movable contact member 6 having a movable contact 6A movable into and out of contact with the fixed contact 8A, a commutation electrode 15 spaced from the movable contact member 6 for receiving an arc 12 generated between the fixed and movable contacts 8A, 6A when they are brought into contact with each other, and a plurality of extinguishing plates 13 for extinguishing the arc 12 transferred to the commutation electrode.

Abstract: An electromagnetic contactor in which at least one pair of contacts which disengage from each other to interrupt a current are provided in an arc-extinguishing chamber defined by a partition wall of electrically insulating material. An absorbing member of porous metal is provided on the inner surface of the partition wall to absorb molten metal particles which are formed by arcing at the time of disengagement of the contacts. A shield plate of electrically insulating material is provided on the inner surface of the absorbing member, and through-holes are formed in the partition wall of the arc-extinguishing chamber and the shield plates in such a manner that the through-holes of the partition wall are non coincident in position with those of the shield plate so that the absorbing member is protected from damage.

Abstract: This invention aims at the reduction of stationary contact element wear and at realizing a significant improvement in the interrupting capability by providing a stationary contact having a hollow cut-out portion formed therein in the vicinity of the portion at which said contact element is joined, and an arc runner electrically connected to said stationary contact at an edge of said hollow cut-out portion closest to said contact element, the arc runner being extended above said hollow cut-out portion.

Abstract: An electromagnetic contactor in which an arc extinguishing chamber is defined by an insulating base and a box attached removably to the insulating base. In the arc extinguish chamber, there are accommodated fixed contact elements having fixed contacts, a movable contact element having a movable contact adapted to be brought into and out of contact with the fixed contacts of the fixed contact elements, a commutation electrode for receiving arcs established when the movable contact comes out of contact with the fixed contacts, arc extinguish metal plates for extinguishing arcs commutated to the commutation electrode, and an extinguishing plate support for supporting the arc extinguishing plates. The extinguishing plate support is formed with a groove or hole for receiving the end portion of the commutation plate so that it is held on the commutation electrode.

Abstract: An electric power switch including a stationary contact piece, a movable contact piece which is moved into and out of engagement with the stationary contact piece, and a commutation electrode arranged near the stationary contact piece and the movable contact piece to receive an arc which is formed when the movable contact piece is disengaged from the stationary contact piece. Current control is performed by moving the movable contact piece into and out of engagement with the stationary contact piece. A plurality of metal arc-extinguishing plates are arranged parallel to the surface of the stationary contact piece and at a predetermined distance from the commutation electrode, extending in the direction in which the movable contact piece is moved with respect to the stationary contact piece. A predetermined distance is maintained between the commutation electrode and the metal arc-extinguishing plates.

Abstract: A switch for making and breaking an electric current and having an arc-extinguishing mechanism. Said switch includes a fixed contact plate having a fixed contact thereon, a movable contact plate having a fixed contact adapted for movement to come into and go out of said fixed contact and an arc deflecting plate provided substantially parallel to said movement. Said arc deflecting plate is made of magnetic metal and is formed with a U-shaped portion in proximity to said fixed contact plate.

Abstract: In an electric power switch in which an arc generated between movable and stationary contacts 6, 14 migrates to an arc runner 15 and a commutation end plate and is extinguished by a grid 2 arranged therebetween, a cut is formed at least in the lower half of the end plate which confronts the grid, whereby the end of the arc is driven towards the center of the end plate and away from a surrounding arc box 1.

Abstract: An electromagnetic contactor comprises a stationary contact point fixed to a stationary contact, a movable contact point fixed to a movable contact to associate with the stationary contact point for switching operations, an arc box for arc extinction for receiving the stationary and movable contacts, a commutation plate fixed to the arc box to commutate arc produced between the stationary and movable contacts and grids placed adjacent to the commutation plate and each having fitting pawls to be inserted into slits formed in the arc box, the top end of said fitting pawls being bent at the portion projecting from the slit to fix the grid to the arc box. The shortest distance X between the commutation plate and the stationary contact and the shortest distance Y between the grid and the stationary contact have relation of X.ltoreq.Y.

Abstract: A power switching device including a fixed contact, a movable contact, an arc runner for transferring a leg of an electric arc to the outside of the fixed contact, a U-shaped fixed contactor electrically connected to the fixed contact, and a deionizing grid for extinguishing the arc. The side of the fixed contact is opposed to the side of the arc runner in three directions. At least the portion of the arc runner close to the fixed contact is kept away from the fixed contact and is physically separated therefrom by an electrically insulating medium. The arc runner is fixed and connected to a portion of the fixed contactor which is on the opposite side of the deionizing grid with respect to the fixed contact. Further, the runner extends so that it forms a continuous path along which the arc runs. Accordingly, after the arc has been transferred to the runner, it is urged toward the deionizing grid, thereby assuring continuous and smooth movement of the arc.

Abstract: A power switchgear is equipped with a stationary contact and contact-maker, a movable contact and contact-maker, a commutating electrode and an arc runner. The elements are constructed and arranged such that when the contacts open, the resultant arc will be quickly driven from the contacts to the commutating electrode and arc runner, to increase the life of the contacts and shorten the arcing time.

Abstract: A strip-shaped fusible member is disposed in a slit formed in an electrically insulating member to be not greater than 1 mm in width. Further a granulated electrically insulating material may be charged around the electrically insulating member within an enclosed housing. Alternatively, a plurality of electrically insulating members may alternate in intimate contact relationship fusible member to form a stack. Each fusible member is connected at both ends to two terminal blocks located on the opposite sides of the stack on those portions higher in level than that portion thereof sandwiched between the insulating members while its end portions are slackened.

Abstract: A circuit interrupter has a pair of contacts, a self-restoring type current limiting element and a first electromagnetic trip device serially interconnected. The current limiting element is connected across a parallel connected resistor and a second electromagnetic trip device. Both trip devices have a common magnetic circuit including a single stationary core and a single movable iron piece. The first trip device responds to a shortcircuiting current flowing through it to open the contacts but the second trip device is operative to open the contacts only after the current limiting element has performed the operation of limiting a shortcircuiting current.