Patent Publication Number: US-7710224-B2

Title: Electromagnetic relay assembly

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The disclosed invention generally relates to an electromagnetic relay assembly incorporating a uniquely configured armature assembly. More particularly, the disclosed invention relates to an electromagnetic relay assembly having a magnetically actuable rotor assembly for linearly displacing a switch actuator. 
   2. Brief Description of the Prior Art 
   Generally, the function of an electromagnetic relay is to use a small amount of power in the electromagnet to move an armature that is able to switch a much larger amount of power. By way of example, the relay designer may want the electromagnet to energize using 5 volts and 50 milliamps (250 milliwatts), while the armature can support 120 volts at 2 amps (240 watts). Relays are quite common in home appliances where there is an electronic control turning on (or off) some application device such as a motor or a light. The present teachings are primarily intended for use as a single pole, 120-amp passing electromagnetic relay assembly. It is contemplated, however, that the essence of the invention may be applied in multi-pole relay assemblies, having unique construction and functionality as enabled by the teachings of the single pole embodiment set forth in this disclosure. Several other electromagnetic relay assemblies reflective of the state of the art and disclosed in United States patents are briefly described hereinafter. 
   U.S. Pat. No. 6,046,660 (&#39;660 Patent), which issued to Gruner, discloses a Latching magnetic relay assembly with a linear motor. The &#39;660 Patent teaches a latching magnetic relay capable of transferring currents of greater than 100 amps for use in regulating the transfer of electricity or in other applications requiring the switching of currents of greater than 100 amps. A relay motor assembly has an elongated coil bobbin with an axially extending cavity therein. An excitation coil is wound around the bobbin. A generally U shaped ferromagnetic frame has a core section disposed in and extending through the axially extending cavity in the elongated coil bobbin. Two contact sections extend generally perpendicularly to the core section and rises above the motor assembly. An actuator assembly is magnetically coupled to the relay motor assembly. The actuator assembly is comprised of an actuator frame operatively coupled to a first and a second generally U-shaped ferromagnetic pole pieces, and a permanent magnet. A contact bridge made of a sheet of conductive material copper is operatively coupled to the actuator assembly. 
   U.S. Pat. No. 6,246,306 (&#39;306 Patent), which issued to Gruner, discloses an Electromagnetic Relay with Pressure Spring. The &#39;306 Patent teaches an electromagnetic relay having a motor assembly with a bobbin secured to a housing. A core is adjacently connected below the bobbin except for a core end, which extends from the bobbin. An armature end magnetically engages the core end when the coil is energized. An actuator engages the armature and a plurality of center contact spring assemblies. The center contact spring assembly is comprised of a center contact spring which is not pre bent and is ultrasonically welded onto a center contact terminal. A normally open spring is positioned relatively parallel to a center contact spring. The normally open spring is ultrasonically welded onto a normally open terminal to form a normally open outer contact spring assembly. A normally closed outer contact spring is vertically positioned with respect to the center contact spring so that the normally closed outer contact spring assembly is in contact with the center contact spring assembly, when the center contact spring is not being acted upon by the actuator. The normally closed spring is ultrasonically welded onto a normally closed terminal to form a normally closed assembly. A pressure spring pressures the center contact spring above the actuator when the actuator is not in use. 
   U.S. Pat. No. 6,252,478 (&#39;478 Patent), which issued to Gruner, discloses an Electromagnetic Relay. The &#39;478 Patent teaches an electromagnetic relay having a motor assembly with a bobbin secured to a frame. A core is disposed within the bobbin except for a core end which extends from the bobbin. An armature end magnetically engages the core end when the coil is energized. An actuator engages the armature and a plurality of movable blade assemblies. The movable blade assembly is comprised of a movable blade ultrasonically welded onto a center contact terminal. A normally open blade is positioned relatively parallel to a movable blade. The normally open blade is ultrasonically welded onto a normally open terminal to form a normally open contact assembly. A normally closed contact assembly comprised of a third contact rivet and a normally closed terminal. A normally closed contact assembly is vertically positioned with respect to the movable blade so that the normally closed contact assembly is in contact with the movable blade assembly when the movable blade is not being acted upon by the actuator. 
   U.S. Pat. No. 6,320,485 (&#39;485 Patent), which issued to Gruner, discloses an Electromagnetic Relay Assembly with a Linear Motor. The &#39;485 Patent teaches an electromagnetic relay capable of transferring currents of greater than 100 amps for use in regulating the transfer of electricity or in other applications requiring the switching of currents of greater than 100 amps. A relay motor assembly has an elongated coil bobbin with an axially extending cavity therein. An excitation coil is wound around the bobbin. A generally U shaped ferromagnetic frame has a core section disposed in and extending through the axially extending cavity in the elongated coil bobbin. Two contact sections extend generally perpendicularly to the core section and rises above the motor assembly. An actuator assembly is magnetically coupled to the relay motor assembly. The actuator assembly is comprised of an actuator frame operatively coupled to a first and a second generally U-shaped ferromagnetic pole pieces, and a permanent magnet. A contact bridge made of a sheet of conductive material copper is operatively coupled to the actuator assembly. 
   U.S. Pat. No. 6,563,409 (&#39;409 Patent), which issued to Gruner, discloses a Latching Magnetic Relay Assembly. The &#39;409 Patent teaches a latching magnetic relay assembly comprising a relay motor with a first coil bobbin having a first excitation coil wound therearound and a second coil bobbin having a second excitation coil wound therearound, both said first excitation coil and said second excitation coil being identical, said first excitation coil being electrically insulated from said second excitation coil; an actuator assembly magnetically coupled to both said relay motor, said actuator assembly having a first end and a second end; and one or two groups of contact bridge assemblies, each of said group of contact bridge assemblies comprising a contact bridge and a spring. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide an electromagnetic relay assembly having certain means for damping contact vibration intermediate contacts of the switching assembly. It is a further object of the present invention to provide an armature assembly having an axis of rotation and which rotates under the influence of the magnetic field created or imparted from an electromagnetic coil assembly. The armature assembly linearly displaces a switch actuator for opening and closing the switch assembly of the relay. To achieve these and other readily apparent objectives, the electromagnetic relay assembly of the present disclosure comprises an electromagnetic coil assembly, an armature bridge assembly, and a switch assembly, as described in more detail hereinafter. 
   The coil assembly essentially comprises a coil, a C-shaped yoke assembly, and a coil axis. The coil is wound around the coil axis, and the yoke assembly comprises first and second yoke arms. Each yoke arm comprises an axial yoke portion that is coaxially alignable with the coil axis and together form the back of the C-shaped yoke assembly. Each yoke arm further, comprises a yoke terminus, which yoke termini are coplanar and substantially parallel to the coil axis. 
   The armature bridge assembly is rotatable about an axis orthogonally spaced from the coil axis and coplanar with the yoke termini. The armature bridge assembly thus comprises a bridge axis of rotation, a bridge, and an actuator arm. The bridge comprises a medial field pathway relative closer in proximity to the coil axis, a lateral field pathway relatively further in proximity to the coil axis, and longitudinally or axially spaced medial-to-lateral or lateral-to-medial field pathways (or transverse field pathways) extending intermediate the medial and lateral pathways. The actuator arm is cooperable with the lateral field pathway via a first end thereof and extends laterally away from the lateral field pathway. 
   The switch assembly essentially comprises switch terminals and a spring assembly between the switch terminals. The spring assembly is attached a second end of the actuator arm. The yoke termini are received intermediate the medial and lateral pathways. As is standard and well-established in the art, the coil receives current and creates or imparts a magnetic field, which magnetic field is directable through the bridge assembly via the yoke termini for imparting bridge rotation about the bridge axis of rotation and linearly displacing the actuator arm. The displaceable actuator arm functions to actuate the spring assembly intermediate an open contact position and a closed contact position, which closed contact position enables current to pass through the switch assembly via the switch termini. 
   Certain peripheral features of the essential electromagnetic relay assembly include certain means for enhancing spring over travel, which means function to increase contact pressure intermediate the switch terminals when the spring assembly is in the closed position. The means for enhancing spring over travel further provide means for contact wiping or contact cleansing via the enhanced contact or increased contact pressure. In other words, the enhanced conduction path through the contact interface may well function to burn off residues and/or debris that may otherwise come to rest at the contact surfaces. The means for enhancing spring over travel may well further function to provide certain means for damping contact bounce or vibration intermediate the first and second contacts when switching from the open position to the closed position. 
   Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated or become apparent from, the following description and the accompanying drawing figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features of our invention will become more evident from a consideration of the following brief description of patent drawings: 
       FIG. 1  is a top plan view of the electromagnetic relay assembly of the present invention with the switch assembly in an open position. 
       FIG. 2  is a top plan view of the electromagnetic relay assembly of the present invention with the switch assembly in a closed position. 
       FIG. 3  is a top perspective exploded type depiction of the electromagnetic relay assembly of the present invention with showing an optional housing cover. 
       FIG. 4  is an exploded perspective view of a first terminal assembly of the switch assembly of the electromagnetic relay assembly. 
       FIG. 5  is an exploded perspective view of a second terminal assembly of the switch assembly of the electromagnetic relay assembly. 
       FIG. 6  is an exploded perspective view of a coil assembly of the electromagnetic relay assembly of the present invention. 
       FIG. 7  is an exploded fragmentary perspective view of a rotor assembly of the armature assembly of the electromagnetic relay assembly. 
       FIG. 8  is an exploded perspective view of the triumvirate spring assembly and a contact button of the switch assembly of the electromagnetic relay assembly. 
       FIG. 9  is a fragmentary side view depiction of the triumvirate spring assembly, the contact buttons, and the armature arm of the present invention showing the contact buttons in a closed position with the triumvirate spring assembly in a substantially coplanar position. 
       FIG. 10  is a fragmentary side view depiction of the triumvirate spring assembly, the contact buttons, and the armature arm of the present invention showing the contact buttons in a closed position with the triumvirate spring assembly in an over travel position for enhancing contact pressure intermediate the contact buttons. 
       FIG. 11  is an enlarged fragmentary side view depiction of the junction at the triumvirate spring assembly and the upper contact button otherwise shown in  FIG. 10  depicting the triumvirate spring assembly in the over travel position for enhancing contact pressure intermediate the contact buttons. 
       FIG. 12  is a diagrammatic depiction of the flux flow through the C-shaped core assembly and the rotor assembly of the electromagnetic relay assembly depicting a diverted and divided field flow through the rotor assembly. 
       FIG. 13  is a side view depiction of a switch terminal assembly as operatively connected to a triumvirate spring assembly and a contact button, the triumvirate spring assembly showing first and second springs with centrally located C-shaped folds, and a third spring with an end-located bend. 
       FIG. 14  is an enlarged fragmentary sectional view as taken from  FIG. 13  depicting the end-located bend of the third spring in rater detail. 
       FIG. 15  is a diagrammatic depiction of a threshold current path directed through the relay terminals as disposed in adjacency to the-rotatable armature assembly and depicting a terminal-sourced magnetic field greater in magnitude than an armature-sourced magnetic field for rotating the armature assembly toward a circuit-opening position. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings, the preferred embodiment of the present invention concerns an electromagnetic relay assembly  10  as illustrated and referenced in  FIGS. 1-3 . The electromagnetic relay assembly  10  of the present invention essentially functions to selectively enable current to pass through switch termini  11  as illustrated and referenced in  FIGS. 1-5 . To achieve these and other readily apparent functions, the electromagnetic relay assembly  10  of the present invention preferably comprises an electromagnetic coil assembly  12  as generally illustrated and referenced in  FIGS. 1-3 , and  6 ; a rotatable armature assembly  13  as generally illustrated and referenced in  FIGS. 1-3 ; and a switch assembly  14  as generally illustrated and referenced in  FIGS. 1-5 . 
   The coil assembly  12  of the present invention preferably comprises a current-conductive coil  15  as illustrated and referenced in  FIGS. 1-3 , and  6 ; a C-shaped core or yoke assembly  16  as illustrated and referenced in  FIGS. 3 ,  6 , and  12 ; and a coil axis  100  generally referenced and depicted in  FIGS. 1 ,  2 ,  6 , and  12 . It may be seen or understood from an inspection of the noted figures that the current-conductive coil  15  is wound around the coil axis  100  and comprises first and second electromagnet-driving termini  17  as illustrated and referenced in  FIGS. 1-3 , and  6 . The yoke assembly or C-shaped core assembly  16  of the present invention is axially received within the coil  15  and preferably comprises first and second yoke arms  18 , one of which is illustrated and referenced in  FIGS. 1-3 , and both of which are illustrated and referenced in  FIG. 6 . It may be seen from an inspection of  FIG. 6  that yoke arms  18  each comprise an axial yoke portion  19  and a substantially planar yoke terminus  20 , which yoke termini  20  are preferably parallel to the coil axis  100  as further referenced and depicted in  FIG. 12 . 
   It is contemplated that the rotatable armature assembly  13  of the present invention may be described as preferably comprising a rotor assembly  21  as generally illustrated and referenced in  FIGS. 1-3 , and  7 ; an actuator or actuator arm  22  as generally illustrated and referenced in  FIGS. 1-3 ,  9 , and  10 ; and an armature axis of rotation  101  as depicted and referenced at a point in  FIGS. 1 ,  2 ,  12 , and  15 , and as a line in  FIGS. 3 and 7 . The rotor assembly  21  preferably comprises first and second uniformly directed or polarized rotor magnets  23  as illustrated and referenced in  FIGS. 7 and 12 ; a rotor plate  25  as illustrated and referenced in  FIGS. 1-3 ,  7 , and  12 ; a rotor bracket as generally illustrated in  FIGS. 1-3 , and  12  and referenced at number  26 ; a rotor housing  27  as illustrated and referenced in  FIGS. 1-3 , and  7 ; a return spring  28  as illustrated and referenced in  FIGS. 3 and 7 ; a rotor pin  29  as illustrated and referenced in  FIGS. 1 and 3 ; and a rotor mount  30  as illustrated and referenced in  FIGS. 1-3 . 
   It may be seen from an inspection of the noted figures that the rotor bracket  26  is attached or otherwise cooperatively associated with first ends of the actuator arms  22 , and that the rotor plate  25  and the rotor bracket  26  (or portions thereof) are preferably oriented parallel to one another by way of the rotor housing  27 . It will be seen that a terminal end of the rotor bracket  26  is zigzagged or zigzag-extended from the central portion of the rotor bracket  26 , which central portion is parallel to the rotor plate  25 . The terminal end of the rotor bracket  26 , as zigzag extended from, and integrally formed with the rotor bracket  26 , attaches the rotor bracket  26  to the actuator arms  22 . 
   It may be further seen that the first and second rotor magnets  23  are equally dimensioned and extend intermediate the rotor plate  25  and the central portion of the rotor bracket  26  for simultaneously and equally spacing the rotor plate  25  and the central portion of the rotor bracket  26  and for further providing a guide way or pathway for so-called Lorenz current or magnetic flux to be effectively transversely directed across the rotor or bridge assembly  21  as diagrammatically depicted in  FIG. 12 . 
   In this last regard, it is contemplated that the armature assembly  13  may be thought of as an armature bridge assembly, which bridge assembly comprises a bridge axis of rotation (akin to the armature axis of rotation  101 ) and a bridge in cooperative association with the armature arm  22 . In this context, the bridge may be thought of or described as preferably comprising a medial pathway (akin to the rotor plate  25 ), a lateral pathway (akin to the rotor bracket  26 ), and longitudinally or axially spaced medial-to-lateral or transverse pathways (akin to the first and second rotor magnets  23 . The armature arm  22  may thus be described as extending laterally away from the lateral pathway or rotor bracket  26  for engaging the switch assembly  14 . 
   The rotor housing  27  essentially functions to receive, house, and position the first and second rotor magnets  23 , the rotor plate  25  and the rotor bracket  26  to form the bridge like structure of the armature assembly  13 . The rotor magnets  23  are uniformly directed such that like poles face the same rotor structure. For example, it is contemplated that the north poles of rotor magnets  23  may face the rotor bracket  26  (the south poles thereby facing the rotor plate  25 ) or that the south poles of rotor magnets  23  may face the rotor bracket  26  (the north poles thereby facing the rotor bracket). 
   The rotor housing  27  may well further comprise a pin-receiving aperture or bore for receiving the rotor pin  29  as may be generally seen from an inspection of  FIGS. 3 and 7 . The pin-receiving aperture or bore of the rotor housing  27  enables rotation of the bridge or armature assembly  13  about the armature axis of rotation  101 . The rotor pin  29 , extending through the pin-receiving bore, may be axially anchored at a lower end thereof by way of a relay housing  48  as illustrated and referenced in  FIGS. 1-3 , and which relay housing  48  is sized and shaped to receive, house, and position the coil assembly  12 , the armature assembly  13 , and the switch assembly  14  as may be readily understood from an inspection of  FIG. 3 . It may be further readily understood from an inspection of  FIG. 3  that the relay housing  48  may, but not necessarily, comprise or be cooperable with a relay cover  49 . 
   In this last regard, it will be recalled that the armature assembly  13  of present invention may be anchored or mounted by way of the rotor mount  30 . Rotor mount  30  may be cooperatively associated with the relay housing  48  (i.e. anchored to the relay housing  48 ) for axially fixing the rotor pin  29 , the fixed rotor mount  30  receiving and anchoring an upper end of the rotor pin  29  so as to enable users of the relay to effectively operate the electromagnetic relay assembly  10  of the present invention without the relay cover  49 . The rotor mount  30  or bridge mount or means for mounting the rotor assembly or bridge assembly may thus be described as providing certain means for enabling open face operation of the electromagnetic relay assembly  10 . It is contemplated, for example, that in certain scenarios a coverless relay assembly provides a certain benefit. For example, the subject relay assembly may be more readily observed during testing procedures. In any event, it is contemplated that the rotor mount  30  of the present invention enables cover-free operation of the electromagnetic relay assembly  10  by otherwise fixing the armature assembly  13  to the relay housing  48 . 
   The switch assembly  14  of the present relay assembly  10  preferably comprises a first switch terminal assembly  31  as generally illustrated and referenced in  FIGS. 1-4 ; and a second switch terminal assembly  32  as illustrated and referenced in  FIGS. 1-3 ,  5 ,  13 , and  14 ; and a triumvirate spring assembly  33  as illustrated and referenced in  FIGS. 1-3 ,  5 ,  8 - 11 ,  13 , and  14 . From an inspection of the noted figures, it may be seen that the first switch terminal assembly  31  preferably comprises a first contact button  34  and a first switch terminus as at  11 . Further, the second switch terminal assembly  32  preferably comprises a second switch terminus as at  11 . 
   The triumvirate spring assembly  33  preferably comprises a second contact button  37  as illustrated and referenced in  FIGS. 1 ,  2 ,  9 - 11 ,  13 , and  14 ; and a first spring  38 , second spring  39 , and third spring  40  as further illustrated and referenced in  FIGS. 5 ,  8 - 10 , and  13 . It may be further seen that the first spring  38  preferably comprises a first contact-receiving aperture as at  41  and a first C-shaped aperture as at  42  in  FIG. 8 , as well as an end-located offset or bend as at  70  in  FIGS. 13 and 14 . Notably, the first C-shaped aperture  42  is preferably concentric about the first contact-receiving aperture  41 . The second spring  39  preferably comprises a second contact-receiving aperture as at  43  and a first C-shaped fold as at  44  in  FIG. 8 . It may be seen from an inspection of  FIG. 8  that the first C-shaped fold  44  has a certain first radius of curvature. The third spring  40  preferably comprises a third contact-receiving aperture as at  45 , a second C-shaped aperture as at  46 , and a second C-shaped fold as at  47 . 
   It may be further seen that the second C-shaped aperture  46  is preferably concentric about the third contact-receiving aperture  45 , and that the second C-shaped fold  47  has a certain second radius of curvature, which second radius of curvature is greater in greater in magnitude than the first radius of curvature (of the first C-shaped fold  44 ). The second spring  39  is sandwiched intermediate the first and third springs  38  and  40  via the second contact button  37  as received or extended through the contact-receiving apertures  41 ,  43 , and  45 . The first C-shaped fold  44  is concentric (about a fold axis) within the second C-shaped fold  47 . The first and second contact buttons  34  and  37  or contacts are spatially oriented or juxtaposed adjacent one another as generally depicted in  FIGS. 1 ,  2 ,  9 , and  10 . In the preferred embodiment, the triumvirate spring assembly  33  is biased in an open contact position intermediate the first and second switch termini  11  and attached to (the lateral end of) the armature arm  22  as perhaps mostly clearly depicted in  FIGS. 9 and 10 . 
   It is contemplated that the first and second C-shaped apertures  42  and  46 , and the end-located offset or bend  70  may well function to provide certain means for enhanced over travel for increasing contact pressure intermediate the first and second contact buttons  34  and  37 . In this regard, the reader is further directed to  FIGS. 9 and 10 . From a comparative consideration of the noted figures, it may be seen that the terminal side ends  53  of the spring assembly  33  may be actuated past the planar portions of the spring assembly immediately adjacent the stem  51  of contact button  37 . The planar portions of the spring assembly immediately (and radially) adjacent the stem  51  of contact button  37  thus form button-stackable spring portions or semi-circular, aperture-defining extensions as referenced at  52  in  FIGS. 8 and 11 . From an inspection of  FIGS. 8 and 11 , it may be seen that the button-stackable portions  52  stack upon the contact button  37  and that terminal side ends  53  of the elastically deform as at  50  for enabling said over travel. 
   In other words, the material (preferably copper) of the spring elements having the C-shaped apertures is more readily and elastically deformable at the termini of the C-shaped apertures as at  50  in  FIG. 8 . Notably, the elastic deformation of the material adjacent termini  50  does not result in appreciable embrittlement of the underlying material lattice (i.e. does not appreciably impart undesirable lattice dislocations) and thus the C-shaped aperture structure or feature of the triumvirate spring assembly provides a robust means for enhanced over travel for further providing a certain added pressure intermediate the contact buttons  34  and  37  for improving conductive contact(s) therebetween. The end-located offset or bend  70  further provides a means for enhanced overtravel for increasing contact pressure and reducing contact bounce of the contacts  34  and  37 . 
   Conduction through the contact buttons  34  and  37  is thus improved by way of the C-shaped aperture-enabled and/or enhanced over travel as generally depicted in  FIG. 10 . It is contemplated that the enhanced contact and resulting conduction provides certain means for improved contact wiping, the means for contact wiping or contact cleansing thus being further enabled by way of the enhanced over travel. In this regard, it is contemplated that the relay assembly  10  of the present invention inherently has a self-cleansing feature as enabled by the C-shaped apertures  42  and  46 . Further, it is contemplated that the C-shaped apertures  42  and  46  (and offset or bend  70 ) may well provide certain means for reducing contact bounce or for otherwise damping contact vibration intermediate the contact buttons  34  and  37  when switching from an open contact state or open switch position (as generally depicted in  FIG. 1 ) to a closed contact state or closed switch position (as generally depicted in  FIG. 2 ). 
   From an inspection of  FIG. 12 , it may be readily understood that the core or yoke termini  20  are loosely received intermediate the rotor plate  25  and the rotor bracket  26 , and that the armature axis of rotation  101  is coplanar with the yoke termini  20 , which axis of rotation  101  extends through the rotor pin  29  (not specifically depicted in  FIG. 20 ). As should be readily understood, the current-conductive coil  15  functions to receive current and thereby creates a magnetic field as further depicted and referenced at vectors  102  in  FIG. 12 . As may be seen from an inspection of the noted figure, the magnetic field  102  is directed through the yoke termini  20  via the rotor assembly (essentially defined by the rotor bracket  26 , the rotor magnets  23 , and the rotor plate  25 ) for imparting armature or bridge rotation about the armature axis of rotation  101  via a magnetically induced torque. 
   The rotor bracket  26  thus functions to linearly displace the actuator arm  22 , which displaced actuator arm  22  functions to actuate the triumvirate spring assembly  33  from a preferred spring-biased open position (as generally depicted in  FIG. 1 ) to a spring-actuated closed position (as generally depicted in  FIG. 2 ). The material construction of the relay assembly  10  (believed to be within the purview of those skilled in the art) and the closed position essentially function to enable 120-amp current to pass through the switch assembly  14  via the first and second contact buttons  34  and  37  and the switch termini  11 . When the coil assembly  12  is currently dormant and the magnetic field is effectively removed, the return spring  28  may well function to enhance return of the triumvirate spring assembly  33  to the preferred spring-biased open position as generally depicted in  FIG. 11 . Should a fault current condition arise, it is contemplated that the electromagnetic relay  10  may preferably further comprise certain closed contact default means, the closed contact default means for forcing the first and second contact buttons  34  and  37  closed during said fault current or short circuit condition(s). In this regard, it is contemplated that the path followed by the Lorenz current or magnetic field path as generally depicted in  FIG. 12  by vector arrows  102 . 
   It is further contemplated that the electromagnetic relay according to the present invention may comprise certain means for defaulting to an open contact position during threshold terminal-based current conditions. In this regard, it is noted from classical electromagnetic theory that streaming charge carriers develop a magnetic field in radial adjacency to the direction of the carrier stream. The reader is thus directed to  FIG. 15  which is a diagrammatic depiction of a threshold current path as at  71  being directed through the relay terminals  31  and  32  via the contact buttons  34  and  37 . A magnetic force vector as at  103  is depicted as terminal-sourced via the charge carrier current flowing through the path  71 . After reaching certain threshold amperage, the magnetic field generated through the terminals  31  and  32  will interact with the permanent magnets or rotor magnets  23  of the rotatable armature assembly  13 . The magnets  23  have an inherent magnetic field directed outward as referenced at vector arrow  104 , the force of which is lesser in magnitude than the force at vector arrow  103 . The difference in force between  104  and  103  as directed causes the rotatable armature assembly  13  to rotate toward an open contact position as diagrammatically shown in  FIG. 15 . This feature can be calibrated by the size and strength of the magnets  23  and the distance between the armature and stationary contacts. 
   While the above descriptions contain much specificity, this specificity should not be construed as limitations on the scope of the invention, but rather as an exemplification of the invention. For example, the invention may be said to essentially teach or disclose an electromagnetic relay assembly for enabling current to pass through switch termini, which electromagnetic relay assembly comprising a coil assembly, a bridge assembly, and a switch assembly. The coil assembly comprises a coil, a coil axis, and a C-shaped core. The coil is wound around the coil axis  100 , and the coil axis extends  100  through the core as at  60  in  FIG. 12 . The core  60  comprises core termini  20 , which core termini  20  are substantially parallel to the coil axis  100 . 
   The bridge assembly comprises an axis of rotation as at  101  and a bridge as at  61  in  FIGS. 12 and 15 ; and a switch actuator as at  22 . The bridge  61  comprises a medial field pathway  63  (i.e. a pathway relatively closer in proximity to the core  60 ), a lateral field pathway  64  (i.e. a pathway relatively further in proximity to the core  60 ), and axially spaced transverse pathways  65  for guiding the field as at  102  intermediate the medial and lateral field pathways  63  and  64 . The actuator arm  22  is cooperable with, and extends away from, the lateral pathway  64  (not specifically depicted in  FIG. 12 ). The core termini  20  are preferably coplanar with the axis of rotation  101  and received intermediate the medial and lateral pathways  63  and  64 . 
   It is contemplated that the transverse pathways  65  provide certain field-diversion means for transversely diverting the magnetic field  102  relative to the coil axis  100  and magnetically inducing a torque, which magnetically induced torque functions to actuate the switch actuator  22 . Said field diversion means may be further described as comprising certain field division means (there being two axis-opposing paths as at  66  in  FIG. 12 ) for creating a magnetic couple about the magnetically induced torque. 
   The switch assembly as at  14  is further cooperable with the actuator arm  22 , which actuator arm  22  is essentially a coupling intermediate the bridge assembly  61  and the switch assembly  14 . The coil functions to create or impart a magnetic field as vectorially depicted at  102 . The magnetic field  102  is directable through the bridge assembly  61  via the core termini  20  for imparting bridge rotation about the axis of rotation  101  via magnetically induced torque. The bridge rotation functions to displace the actuator arm  22 , which displaced actuator arm  22  physically opens and closes the switch assembly  14 . As is most readily understood in the arts, the closed switch assembly  14  enables current to pass therethrough. 
   The switch assembly  14  comprises certain spring means for enhancing spring over travel, said means for enhancing the closed switch position by way of increasing the contact pressure intermediate contact buttons  34  and  37 . The spring means for enhancing spring over travel further provide contact wiping means, and vibration damping means. The contact wiping means are contemplated to effectively self-cleanse the switch assembly  14 , and the vibration damping means function to damp contact vibration when switching from open to closed switch positions. The spring means for enhancing spring over travel may thus be said to enhance the closed switch position by increasing contact pressure intermediate the contacts, by maintaining a residue free contact interface, and by damping contact vibration when closing the contacts. 
   Although the invention has been described by reference to a number of embodiments it is not intended that the novel device or relay be limited thereby, but that modifications thereof are intended to be included as falling within the broad scope and spirit of the foregoing disclosure and the appended drawings. For example, the foregoing specifications support an electromagnetic relay assembly primarily intended for use as a single pole, 120-amp passing relay assembly. It is contemplated, however, that the essence of the invention may be applied in multi-pole relay assemblies, having unique construction and functionality in their own right, but which are enabled by the teachings of the single pole embodiment set forth in this disclosure.