Abstract: Disclosed is a two-section conductor type ground fault circuit interrupter with a reverse wiring protection function. A patch key switch is arranged on a PCBA assembly, a conduction spring is mounted between an electric plug bush and the PCBA assembly, and an electronic relay is mounted between an output end of a load copper sheet and the conduction spring. A condition that a metal key is exposed to generate a spark or a metal press piece falls off is avoided, so a two-section conductor structure with the reverse wiring protection function is achieved.

Abstract: Not only a cylindrical weight is inserted with a clearance around an outside of a first axis part or a second axis part that extends opposite to the first axis part and is movable freely in an axial direction but also an annular seat surface on which the cylindrical weight is able to be seated by self-weight is provided with a governor valve. A projecting part(s) is provided with only a part in circumferential direction of one of the annular seat surface and a lower end surface of the cylindrical weight. The cylindrical weight is made sure to be supported on the annular seat surface in an inclined state from an upright posture by contact of the projecting part(s) with the other of the annular seat surface and the lower end surface of the cylindrical weight.

Abstract: Disclosed is a switch apparatus of a vehicle that includes a switch body that is connected to a connector of an electronic apparatus and includes a relay board disposed in an inner space thereof. The apparatus further includes a coupling portion disposed on a bottom of the switch body, formed by a conductor, and coupled to a fixation bracket. Additionally, an earth member includes a base formed by the conductor and is disposed in a lower part of the inner space of the switch body, and coupled on the top of the coupling portion and a clamping bar respectively extended upward at both sides of the base and coupled with an earth terminal formed on the bottom of the relay board.

Abstract: An electromagnetic actuator device has a core unit with a coil device designed to cooperate with armature units displaceably guided relative to the core unit in response to current applied to the coil device, wherein the core unit is designed to cooperate with a plurality of spatially separated plunger units of the armatures so that an electromagnetic interaction takes place with the plurality of plunger units in response to current applied to a coil of the coil device.

Abstract: An electromagnetic actuator device, comprising a coil unit (14), which surrounds a first yoke section (13) of a stationary yoke unit and can be activated by energizing the coil unit; and armature elements (10, 12), which are guided so as to be movable relative to the yoke unit and which interact with an output-side actuating partner and which can be driven in order to perform an actuating movement. The armature elements interact with at least one second yoke section (15, 16) of the yoke unit to form an air gap (26, 28) for a magnetic flux produced by the activated coil unit.

Abstract: An electromagnetic relay includes a fixed iron core; a movable iron core disposed opposing to the fixed iron core; a coil for generating a magnetic force when energized to make the movable iron core attracted by the fixed iron core; a movable contact coupled with the movable iron core; a fixed contact disposed opposing to the movable contact; and a reset spring for resetting the movable iron core when the coil is de-energized. The movable iron core includes a base body to which an expanding force of the reset spring is applied and a movable member provided independently from the base body. The movable member is attracted by the fixed iron core when the coil is energized to move integrally with the base body, and is reset by the expanding force of the reset spring when the coil is de-energized to slide independently from the base body.

Abstract: A two-stage solenoid valve for an electropneumatic valve control unit, e.g., a pilot control unit of a pressure modulator, includes a solenoid system to which a first and second current intensity can be applied as well as a solenoid valve device with a primary side connectable to a first compressed-air supply and a secondary side connectable to a second compressed-air supply. A primary valve encompassing an adjustable primary armature biased by a primary armature spring is provided on the primary side, and a secondary valve encompassing an adjustable secondary armature biased by a secondary armature spring is provided on the secondary side. The solenoid valve device can be a valve cartridge insertable from one side. Diameters of a front (in relation to insertion direction) region and a central region of the valve cartridge are smaller than or equal to the diameter of a rear region of the valve cartridge.

Abstract: The invention concerns an electromagnetic actuator (7) with a coil (8) and at least two armatures (12, 17) being movable along an axis (16) and being acted upon by a magnetic field generated by the coil (8). It is endeavoured to achieve large control opportunities by simple means. For this purpose, it is provided that one armature (12) is acted upon by a larger drive force from the magnetic field than another armature (17).

Abstract: A vehicle power system includes an electrical power source, an electrical bus, and a contactor electrically connected with the electrical power source and electrical bus. The contactor includes first and second poles, dual plungers each operatively associated with one of the first and second poles, and an electromagnetic coil configured to cause at least one of the dual plungers to move if the coil is energized.

Abstract: An impact solenoid assembly for an electrical receptacle includes an armature having first and second ends. A resilient member is disposed between a latch and the second end of the armature. The resilient member spaces the armature from the latch. A plunger abuts the second end of the armature. When the solenoid is activated, the solenoid drives the armature toward the plunger, thereby creating momentum in the armature prior to striking the plunger. This increases the force with which the armature and plunger strike the latch.

Abstract: An electromagnetic actuator having an annular pole piece and an annular armature with surfaces formed thereon through which a magnetic flux passes. The armature is axially movable relative to the pole piece between a first position and a second position. Magnetic flux is efficiently transmitted between the pole piece and the armature and the pole piece can be employed to guide the armature for movement thereon.

Abstract: An actuator having a linear motor and a plunger that is movable by the linear motor along an axis. The plunger includes an annular flange and a rim that is coupled to an outer periphery of the flange. The annular flange is oriented generally perpendicular to the axis. A plurality of apertures is formed through at least one of the flange and the rim. A locking differential and an axle assembly are also provided.

Abstract: An electromagnetic actuator having an annular pole piece and an annular armature with surfaces formed thereon through which a magnetic flux passes. The armature is axially movable relative to the pole piece between a first position and a second position. Magnetic flux is efficiently transmitted between the pole piece and the armature and the pole piece can be employed to guide the armature for movement thereon.

Abstract: An electromagnetic valve assembly having a dual armature solenoid for controlling two valves is disclosed. In one embodiment, the solenoid may include a first pole piece, a second pole piece spaced from the first pole piece, a coil disposed about at least a portion of the first pole piece, a first armature extending laterally across the first pole piece and the second pole piece, and a second armature extending laterally across the first pole piece and the second pole piece. In one illustrative embodiment, the first armature and the second armature pivot relative to the second pole piece. In another illustrative embodiment, the first armature and the second armature pivot relative to the first pole piece. In yet another illustrative embodiment, the first armature and the second armature pivot relative to opposite pole pieces. In any case, the coil may electromagnetically actuate the first and second armatures to selectively open and/or close corresponding valves or other actuatable components.

Abstract: A solenoid is provided which, in the preferred embodiment, has a housing having an axial opening in it. The housing has a divider mounted in the axial opening to separate the axial opening into a first segment and a second segment. Respective ones of a first pole piece and a second pole piece are located on opposite sides of the divider. The first pole piece is moveable with the first segment between an extended position and a retracted position, the first pole piece having a plunger positioned at an end of the first pole piece. A permanent magnet is moveably mounted from the axial opening and is moveable independently of the second pole piece between at least a first position adjacent to the divider, and a second position adjacent the second pole piece. The construction provides a fast acting, low cost latching solenoid construction.

Abstract: An electromagnetic actuator assembly that includes an annular frame, a coil assembly, an annular armature, a plunger and a sensor. The coil assembly is coupled to the frame and includes an annular core and an annular coil. The annular armature is received in the frame and abutted against the plunger. A sensor target can be coupled to the armature or the plunger and includes a radially outwardly extending sensor target. The sensor is coupled to the frame and configured to sense a position of the sensor target. A method for operating an electromagnetic actuator is also provided.

Abstract: A three-dimensional-information detecting system includes a switching portion that sequentially selects sensor coils of a three-dimensional-information detecting device. Electromagnetic coupling is used to perform signal transmission and reception between the sensor coils and input coils in input elements of a three-dimensional-information inputting device which are mutually perpendicularly provided. A signal received by a selected sensor coil is detected by a detecting portion. From the detected signal, three-dimensional information, such as the position and attitude of the three-dimensional-information inputting device, is calculated by a control unit.

Abstract: An electromagnetic valve assembly having a dual armature solenoid for controlling two valves is disclosed. In one embodiment, the solenoid may include a first pole piece, a second pole piece spaced from the first pole piece, a coil disposed about at least a portion of the first pole piece, a first armature extending laterally across the first pole piece and the second pole piece, and a second armature extending laterally across the first pole piece and the second pole piece. In one illustrative embodiment, the first armature and the second armature pivot relative to the second pole piece. In another illustrative embodiment, the first armature and the second armature pivot relative to the first pole piece. In yet another illustrative embodiment, the first armature and the second armature pivot relative to opposite pole pieces. In any case, the coil may electromagnetically actuate the first and second armatures to selectively open and/or close corresponding valves or other actuatable components.

Abstract: A valve assembly comprises two valves and a single solenoid actuator with only one magnetizing coil that controls both valves. The corresponding magnetic circuit comprises a yoke with only two pole pieces. The valves are arranged concentric to one another. The valve closing element of the outer valve is connected to an armature by means of a sleeve. The cup thus formed receives the armature that is connected to the valve closing element of the inner valve. The pole piece and the armature form a transmission air gap through which the sleeve extends. A coupling air gap is formed between the armatures. The armature and the pole piece form a working air gap. The valves are opened collectively and are able to close independently of one another when the coil is rendered currentless.

Abstract: A solenoid type device as a magnetic switch of a starter 10 comprises an exciting coil 3f that is energized and generates magnetic force, a plunger 3a that is a moving core which is a part of the magnetic circuit, and a fixed core 3j that faces the moving core and is also a part of the magnetic circuit. The moving core plunger 3a is divided into concentrically the first plunger 31 and the second plunger 32a. This configuration allows the second plunger 32a to be attracted first and then the first plunger 31a to be attracted. Thereby, it is possible to make a small and light magnetic switch while ensuring that the magnetic switch maintains sufficient attraction force as well as to increase reliability of operations of the magnetic switch even when battery voltage is low.

Abstract: A solenoid is provided which, in the preferred embodiment, has a bobbin having an axial opening in it. A divider is mounted within the opening. Respective ones of a first pole piece and a second pole piece are located on opposite sides of the divider. A permanent magnet is moveably mounted from the axial opening and is moveable independently of the second pole piece between at least a first position adjacent to the divider, and a second position adjacent the second pole piece. The construction provides a fast acting, low cost latching solenoid construction.

Abstract: A resettable switching device, e.g. a relay, comprises a fixed contact (18) and a movable contact (28). A solenoid (12) is fixed relative to the fixed contact and a ferromagnetic plunger (20) carries the movable contact. A spring (24) biases the plunger away from the fixed contact so the device is normally open. When the device is set a further ferromagnetic element, e.g. a plunger (22), holds the first plunger (20) in a closed-contact position by magnetic attraction against the action of the spring (24). When a predetermined current condition exists in the solenoid the magnetic attraction between the element and plunger is reduced below the level necessary to hold the plunger so that the movable contact disengages the fixed contact.

Abstract: An electromagnetic dual-action control valve with a housing (2), with connections (15, 16, 17) for inflow and outflow lines for a pressure medium, with a solenoid (3) and with two armatures arranged to move within the solenoid (3) for opening and closing the line connections. To simplify the structure of such a dual-action control valve, it is provided that one of the armatures is formed as a hollow armature (4) with a closed end (11), within which an inner armature (5) is arranged to move coaxially, and the hollow armature (4) has openings (20, 21) for the pressure medium, of which one opening (21) can be closed by a sealing surface (13) of the inner armature (5).

Abstract: A single coil, two operator controller for simultaneously actuating two spaced apart magnetically responsive operators has a bar extending between the spaced apart operators, and a coil on the bar, between the operators for creating a magnetic field for moving the magnetically responsive operators. The single coil, two operated controller is particularly suited for operating a gas valve.

Abstract: A solenoid includes first and second armatures disposed on either side of a solenoid core. The core includes first and second sets of legs disposed on opposite sides of a central member. A drive circuit provides a first current level to cause flux to flow in a first path through the core and thereby move the first armature without substantially moving the second armature. The drive circuit can provide a second current level greater than the first current level to saturate the first path and thereby redirect flux into a second core path to move the second armature.

Abstract: An electromagnetic actuator, particularly for use with valves in the automotive field, such as, for example, exhaust-gas recirculation valves, secondary-air valves, etc., having a housing with an electrical connector plug, a magnetic yoke, a coil unit, a guide element, a magnetic core and an armature that cooperates with a valve adjusting member. The armature is formed by first and second armature elements, the second armature element being in the form of a disk mounted so that it is spaced from the first armature element by an air gap when current is not supplied to the actuator whereby high, abrupt force is developed on the first armature element to open the valve when current is supplied.

Abstract: A solenoid valve having a coil, a pair of armatures including an inner armature slidable within a coaxial outer armature and the outer armature slidable within the coil, and a pair of valves. One of the valves is at or near the end of the outer armature extending from the coil, and the other valve is at or near an end of the inner armature extending from the valve-bearing end of the outer armature. Thus, both valves are at the same side of the solenoid valve assembly. When a magnetic force is applied by a current flowing in the coil, at least the inner armature is drawn in a direction into the coil so as to open the valve at its end. An increased magnetic field caused by increased current in the coil eventually results in the outer armature being drawn into the coil, thereby also opening the valve at the end of the outer armature. The valve is suitable for use in many fluid control applications, but is especially useful for control of gases and for control of intermittent gas ignition systems.

Abstract: A ground fault circuit interrupter has a pair of stationary contacts and a pair of movable contacts mounted in a housing. Also included is an electromagnetic coil mounted in the housing for generating an electromagnetic field. The interrupter also has a plunger and an armature, each slidably mounted at least partially within the electromagnetic coil. The armature can be magnetically driven by the coil against the plunger. A latch means is included for releasably holding the pair of movable contacts against the pair of stationary contacts. A fault detector can detect a fault in an electrical distribution system in order to actuate the electromagnetic coil.

Abstract: A solenoid including a single coil of windings, an immovable stator, and opposed first and second armatures defining an air gap therebetween. A driving circuit energizes the coil to cause the first and second armatures to simultaneously move toward each other from respective first positions to respective second positions.

Abstract: The invention is directed to an actuator which is mounted on a base to rotate a rotary member about a rotational axis thereof. The actuator includes a first magnetic rotary member which is rotatably mounted on the base about the axis, and provided with a first engaging portion which traces a peripheral locus about the axis. It also includes a second magnetic rotary member which is rotatably mounted about the axis, and provided with a second engaging portion engageable with the first engaging portion on the peripheral locus about the axis. The first engaging portion is moved to be engageable with the second engaging portion when the first rotary member is rotated in one direction relative to the second rotary member, and the first engaging portion is moved to be away from the second engaging portion when the first rotary member is rotated in the opposite direction.

Abstract: The invention concerns a bistable magnetic drive with an assembled armature 3, 4 consisting of a high-grade, disk-shaped permanent magnet 3 with two appropriately shaped pole pieces 4,4' and displaceable sideways off the coil 1 transversely to its axis inside an electromagnetic annular pole-piece Rp between two electromagnetic stop pole-pieces 5, 5'. The invention describes illustrative embodiments and applications of this drive as an excursion and oscillating magnet, further a circuit for DC operation. A capacitor circuit furthermore allows mono-stable operation. The advantages are a lightweight armature, high efficiency, bilateral operation, versatility and simplicity.

Abstract: An electromagnetic actuator suitable for use in combination with the mechanisms of cameras and the like. The electromagnetic actuator has a single electromagnet, and first and second armatures disposed opposite to the opposite attracting surfaces of the electromagnet, respectively. The first armature actuates a first operating lever for operating the shutter release mechanism of a camera, and the second armature actuates a second operating lever for operating the diaphragm of the camera. The first armature is separated from the attracting surface and the second armature is in contact with the attracting surface while the electromagnet is not energized. When the electromagnet is energized, the first armature is attracted to the attracting surface to actuate the first operating lever for releasing the shutter.

Abstract: A tape recorder having a controller for a movable member is able to control the movement of the member between two states by one electromagnet. The controller includes an electromagnet having first and second attracting parts which correspond to first and second attracted parts, a driving member which is driven through a fixed motion by a driving source, a combining part for moving which is installed on said movable member so as to separate from the driving member or be maintained in the combined state with said driving member by said first attracted part, a combining part for keeping position which is installed on said movable member to maintain said movable member in the second position by combining with the second attracted part and a leaving prevention part for preventing the leaving from said driving member of said combining part for moving when said movable member is at a position from halfway between said first and second positions to its second position.

Abstract: An electromagnetic relay having a double armature structure comprises: an electromagnet; a pair of armatures which are individually rotatably arranged at the right and left positions of the electromagnet and are symmetrically rotated by the attractive forces of the electromagnet against a return spring; and a pair of contact mechanisms which are closed or opened by the rotation of the armatures. The electromagnet has a pair of iron cores to respectively attract the pair of armatures, or has a single iron core and respectively adsorbs the pair of armatures at both ends of this iron core. With this relay, even if one of the contact mechanisms was not open due to the melt-bonding, the other is opened.

Abstract: A character selecting mechanism for a printer having a plurality of type wheel units arranged axially on a shaft. The character selecting mechanism comprises a plurality of electromagnetic clutches each having a solenoid, a sleeve rotatably received in the center hole of the solenoid and rotated continuously during a printing cycle, and a pair of selector plates resiliently pressed against the opposite end surfaces of the sleeve, respectively, so as to be attracted to the sleeve and to be turned by the sleeve when the solenoid is energized, having tongues facing opposite to each other to form part of a magnetic path for the magnetic lines of force of the solenoid with a small gap therebetween and in contact with each other through a small contact area. Each electromagnetic clutch controls a pair of type wheel units to stop the respective type wheels of the pair of type wheel units individually to position the selected characters of the type wheels at the printing position.

Abstract: A magnetic core (3) surrounded by a coil (1, 2) bears a first pole shoe (4) forming a large-surface air-gap with two zones (5a, 6a) of two armatures (5, 6) fixed to one another and disposed magnetically in parallel.The core (3) is continued beyond the coil and at this end bears a second pole shoe (9) which together with two other zones (5c, 6c) of the armatures forms a second large-surface air-gap disposed magnetically in series with the first.

Abstract: A relay includes two armatures each having a contact spring and a contact piece secured thereto which interacts with the respective cooperating contact element. The two movable contact pieces are electrically connected by a stranded copper conductor so that a series connection of the two contacts is formed. The series connection can be interrupted twice by the two armatures which switch independently of one another so that a reliable opening of the circuit is assured even if one of the contacts fuses. The relay is particularly useful for safety circuits such as in motor vehicles.

Abstract: A solenoid is disclosed which uses a plastic coil bobbin as the bearing surface for the armature, the body of which extends coaxially through the central cylindrical cavity of the bobbin. Extending into this cavity, from the end opposite the armature, is a plug which is rigidly fixed to the bobbin by an outer housing that surrounds the bobbin and has a skirt which captures a flanged end of the plug. A plunger that extends through an axial bore in the plug floats freely, coaxially of the bobbin. The interior end of the plunger has an enlarged head that is received within a bore in the armature body. A bias spring is situated between this plunger head and a counterbore in the plug.

Abstract: An electromagnet assembly is provided. It has a first movable core and a second movable core provided in association with a coil. The first movable core is energized toward the second movable core by a first spring while the second movable core is urged in the direction away from the first movable core by a second spring which has larger biasing force than that of the first spring. When the second movable core is attracted by magnetic excitation of the coil, the first movable core is pressed downwards by the second movable core.

Abstract: A solenoid-operated plunger device comprising a frame and a solenoid coil contained within the frame. Two or more movable plungers, separated by a barrier, are located within the solenoid coil. The plungers project the ends of the solenoid coil, and are slidable within the solenoid coil on parallel axes. A return spring is connected to each plunger for controlling the movement of the plunger.

Abstract: An improved vacuum pump driven by a unique electrically powered servo motor. The vacuum pump comprises an extremely simple and inexpensive pump arrangement utilizing a reciprocating piston and a rolling lobe diaphragm to eliminate the need for close tolerances while still providing high efficiency. The servo motor includes a pair of relatively movable sequentially operating armatures which eliminate the need for any external timing mechanism or for any complex delay mechanism. The servo motor of the present invention is inherently capable of operating the pump as a self-actuating demand pump.

Abstract: A dynamically balanced vibratory feeder system having a material handling component and a counterweighting component, the two components being drivingly interconnected and driven in opposed relative directions in a balanced fashion. The material handling component includes an elongated platform formed to accommodate a material conveying trough. The counterweighting component includes a rigid plate and a balancing counterweight secured to the plate and located between the elongated platform and the plate. The material handling and counterweighting components are periodically driven in opposed relative directions by an electromagnet driver which includes a driving portion and a driven portion. The driving portion is essentially isolated from the reciprocal movement of the material handling and counterweighting components, while the driven portion is connected to drive the material handling and counterweighting components.

Abstract: A solenoid having a linear pull stroke includes a coil operated plunger (16) having a lost motion coupling (20,28,32,38,40) adapted to be connected with a load in order to allow the plunger (16) to retract a predefined distance during the initial part of the stroke thereby to develop a higher level of pulling force before substantial force is actually imparted to the load. The plunger (16) comprises an elongate body (18) having a piston-like link (28) slidably mounted in a cavity (20) at one end of the body (18) and adapted to be coupled with the load. A spring (36) trapped between the link (28) and the body (18) resets the link (28) relative to the body (18) before the pull stroke is completed.

Abstract: This invention relates to force motors that are used in single stage hydraulic valves that are responsive to electrical input signals. The inertia of the force motor is reduced by having only a small portion of the force motor move. By reducing the mass of the moving parts of the force motor the force motor may be used with an increased speed of response.

Abstract: An electromagnetic solenoid is adapted to open and close an associated valve or to reciprocally engage a slideable member. The solenoid includes an electromagnetic and multi-piece armature enclosed within a protective housing. The armature comprises an inner pole piece operatively connected to an outer pole piece to initially provide a multi-level air gap with respect to the electromagnet. The inner pole piece is telescopically received within the outer pole piece and may over-travel the outer pole piece once the motion of the outer pole piece has ceased.

Abstract: A latching relay employing an electro-magnetic relay coil having associated therewith opposite end armatures. This relay coil receives operating power by way of an input contact member. One of the armatures carries a manually operated switch which also includes an end for actuating the closure contact. The opposite armature functions to assist in the manual switching and in its inactive state blocks operation of the primary armature. Another contact is associated with one of the armatures for providing high power transfer.

Abstract: A novel electropneumatic servoactuator utilizing a fluid pressure control signal chamber and a duty-cycle control valve alternating between a fluid supply pressure port means and port means venting the chamber to the atmosphere and controlling fluid pressure in the chamber. The control valve is driven by electromagnetic means comprising a coil responsive to an electrical input signal. Pressure responsive actuator means moves in response to the chamber pressure level for providing a mechanical position output. Feedback means senses movement of the actuator means and throttles the fluid flow in one of said port means. In another aspect of the invention, an auxiliary dump release valve armature means is also driven by the coil in preferably magnetic series circuit arrangement with the control valve and coil for rapidly porting the control chamber to the atmosphere for emergency release.

Abstract: A solenoid for operating various devices, such as a reversing valve, and which includes a C-frame having a first non-magnetic bushing mounted in the bight portion of the C-frame. A coil assembly is removably mounted in the C-frame and is retained therein by a flux plate which is snapped in place between the outer ends of the legs of the C-frame and retained by a friction fit. The coil assembly is provided with retainer members that seat in retainer notches in the C-frame bight portion and the flux plate, for retaining the coil assembly against movement. A cylindrical, non-magnetic core guide is mounted axially through the coil assembly and has slidably mounted therein a solenoid plunger and a pole piece. A second non-magnetic bushing is mounted in the flux plate. The solenoid plunger has a reduced diameter outer end which is slidably mounted in the first bushing, and the pole piece has a reduced diameter outer end which is slidably mounted through the second bushing.

Abstract: A solenoid is provided in which the armature unit includes a primary plunger and a secondary plunger arranged in telescopic association one with the other and disposed so that the secondary plunger, having both a smaller mass and a smaller air gap than the primary plunger, initially draws in the primary plunger against the anvil without altering the stroke of the primary plunger. The coaction between the two plungers materially reduces the electric energy required to operate the solenoid. While not limited in its application to any particular form of magnetic circuit or to any particular size of magnet, the invention is especially useful in connection with mechanism in which a miniature solenoid is required, and also when it is required to employ a solenoid in which the armature stroke is relatively large and the power requirement must be small.

Abstract: A coil and trip mechanism to interrupt an electrical circuit having a dual counter-balanced armature arrangement, one a clapper type armature and the other a plunger type. The clapper armature is mounted for movement between a latched position and a tripped position. The plunger armature is mounted for sliding reciprocal movement in and out of the center of the coil between an extended latched position and a retracted tripped position. The armatures are oppositely spring biased toward each other, the stronger bias being provided by a coil spring urging the plunger armature toward the clapper thus holding it away from the trip coil in the latched position until the trip coil is energized. When the trip coil is energized, its electromagnetic force draws the plunger inwardly compressing the coil spring thus neutralizing its biasing force towards the clapper.