Patent Document

CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of application Ser. No. 12/546,126, filed Aug. 24, 2009, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     U.S. Pat. No. 7,205,496 to Schober et al. discloses a sub-miniature switch including a housing, an actuator and terminals. The actuator protrudes from the housing at a position offset from the center of the housing. The terminals are electrically coupled with fixed contacts positioned within the housing. A contact maker is moved via the actuator and held in a first or second switching position by means of a bistable spring arrangement. An additional component, a separator or auxiliary actuator, is in snap-fit engagement with the cover of the housing and is pushed through by the actuator as the switch is operated. The contact point of the fixed contacts is on a side of the housing which is opposite the actuator. The separator or auxiliary actuator is moved in the direction of the contact position by the actuator. 
     U.S. Pat. No. 6,486,571 to Miller et al. discloses a circuit for connecting a power distribution bus to a battery. The circuit has a connector circuit and a switch. The battery has a positive battery terminal and a negative battery terminal. The switch has a control terminal, a first terminal, and a second terminal. A contactor circuit is coupled between the battery and the power distribution bus. The contactor circuit has a solenoid and a plunger switch that is operably coupled by the solenoid. In one embodiment, the connector circuit has a switch used to allow the connector terminals to be coupled at different times to the circuit. In a second embodiment, different length terminals may be used to enable coupling of the battery terminals at different times. 
     U.S. Pat. No. 5,661,274 to Koehler discloses a double-pole single-throw switch that has a pair of spaced stationary contacts adapted for carrying current to individual circuits. A cantilevered, torsionally flexible, electrical current carrying arm has a pair of correspondingly spaced moveable contacts mounted on the free end and disposed adjacent the stationary contacts. A toggle spring actuator has one reaction end engaging a slot in the end of the electrical current carrying arm for effecting relative lost motion movement and impacting the sides of the slot for causing rapid making and breaking and a wiping motion of the contacts. The spring engages the slot midway between the contacts to permit angular movement to accommodate misalignment of the stationary contacts. 
     SUMMARY 
     An automotive vehicle includes an electrical power source disposed within the vehicle, an electrical bus, and a double-pole, single-throw contactor electrically connected with the electrical power source and electrical bus. The contactor includes two poles and a split plunger configured to sequentially close the poles. 
     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. 
     A double-pole single-throw contactor includes two poles, dual plungers and an electromagnetic coil wound around the dual plungers. Each of the dual plungers is configured to independently close one of the two poles. 
     While example embodiments in accordance with the invention are illustrated and disclosed, such disclosure should not be construed to limit the invention. It is anticipated that various modifications and alternative designs may be made without departing from the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an automotive power system. 
         FIG. 2  is a block diagram of another automotive power system. 
         FIGS. 3A and 3B  are side and top view, schematic diagrams of a double-pole single-throw contactor. 
         FIGS. 4A and 4B  are side and top view, schematic diagrams of another double-pole single-throw contactor. 
         FIG. 5  is a schematic diagram, in cross-section, of an enlarged portion of the double-pole single-throw contactor of  FIGS. 4A and 4B . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , an automotive power system  10  for a vehicle  12  may include a high voltage power source  14  (e.g., +300 V battery, ultra capacitor, etc.), high voltage bus  16 , precharge circuit  18  and contactors  20 ,  22 ,  24  (e.g., switches). As known in the art, the high voltage bus  16  may supply power from the high voltage battery  14  to various loads, such as an electric machine, etc. 
     The contactor  20  is electrically connected with the battery&#39;s low (negative) side and the high voltage bus  16 . The contactor  22  is electrically connected with the battery&#39;s high (positive) side and the high voltage bus  16 . The contactor  24  is electrically connected with the high voltage bus  16  and the precharge circuit  18 . The contractors  20 ,  22 ,  24  may be selectively opened or closed under the control of one or more controllers (not shown) in a known fashion. 
     To precharge the system  10 , the contactor  20  is closed and the contactor  24  is subsequently closed as known in the art. Precharge of the system  10  is complete when, for example, the voltage across the contactor  24  falls within some acceptable limit (e.g., 20 V), and a predetermined period of time (e.g., 150 msec) has passed. The period of time may be determined based on vehicle test data, etc. Once the system  10  has been precharged, the high side contactor  22  is closed and the contactor  24  is subsequently opened. Electrical power may then flow from the high voltage battery  14  to loads electrically connected with the high voltage bus  16 . 
     Each of the contactors  20 ,  22 ,  24  may be relatively expensive and add considerable material cost to the vehicle  12 . A reduction in the number of contactors may, therefore, result in a reduction of material cost to the vehicle  12 . 
     Referring now to  FIG. 2 , numerals of  FIG. 2  that differ by 100 relative to the numerals of  FIG. 1  are used to designate similar elements in  FIG. 2 . Unlike the system  10  of  FIG. 1 , a single contactor  126  has been electrically connected between the high voltage battery  114  and the high voltage bus  116 . The system  110  thus has only two contactors as opposed to three. 
     Referring now to  FIGS. 3A and 3B , a double-pole single-throw contactor may include contacts  128 ,  130 ,  132 ,  134 , poles  129 ,  133 , a spring-loaded plunger  136  and a coil  138 . The plunger  136  is mechanically connected with the poles  129 ,  133 . As known in the art, passing a current through the coil  138  will generate an electromagnetic field that causes the plunger  136  to move such that the pole  129  touches the contacts  128 ,  130 , and the pole  133  touches the contacts  132 ,  134  respectively. 
     Referring now to  FIGS. 2 ,  3 A and  3 B, if the contactor of  FIGS. 3A and 3B  were to be used as the contactor  126  of  FIG. 2  (the contacts  128 ,  130  may be electrically connected with the low side of the power source  114  and the low side of the high voltage bus  116  respectively; the contacts  132 ,  134  may be electrically connected with the high side of the power source  114  and the high side of the high voltage bus  116  respectively), the system  110  could not be properly precharged as the high side and low side of the power source  114  would be simultaneously connected with the high voltage bus  116  upon activation of the plunger  136 . 
     Referring now to  FIGS. 2 ,  4 A and  4 B, the double-pole single-throw contactor  126  may include contacts  140 ,  142 ,  144 ,  146 , poles  141 ,  145 , a split (or dual) plunger  148  (of any shape/configuration), coils  150 ,  152 , and a moveable spring-loaded pin  153 . The coil  150  is wound around the split plunger  148 . The coil  152  is wound around the moveable spring-loaded pin  153 . 
     The contact  140  may be electrically connected with the battery&#39;s low side (as designated by “A”). The contact  142  may be electrically connected with the low side of the high voltage bus  116  (as designated by “C”). The contact  144  may be electrically connected with the battery&#39;s high side (as designated by “B”). The contact  146  may be electrically connected with the high side of the high voltage bus  116  (as designated by “D”). The coils  150 ,  152  may each be electrically connected with a low voltage source such as a +12 V battery, etc. (as designated by “E,” “F,” “G” and “H”). 
     In the embodiment of  FIGS. 4A and 4B , the split plunger  148  may be spring biased in the open position and include leg portions  154 ,  156 . The leg portion  154  is mechanically connected with the pole  141 . The leg portion  156  is mechanically connected with the pole  145 . Passing a current through the coil  150  will generate an electromagnetic field that causes the leg portion  154  to move such that the pole  141  touches the contacts  140 ,  142 . The same, however, is not necessarily true for the leg portion  156 . The moveable spring-loaded pin  153 , if engaged, may block the leg portion  156  from moving. As such, the poles  141 ,  145  may be sequentially closed via control of the moveable spring-loaded pin  153 . 
     Referring now to  FIG. 5 , the moveable spring-loaded pin  153  may be spring biased such that if no current is passing through the coil  152 , the pin  153  blocks movement of the leg portion  156 . If, however, current is passing through the coil  152  (and the coil  150 ), the pin  153  may move such that it no longer blocks the path of the leg portion  156 , and the leg portion may move such that the pole  145  touches the contacts  144 ,  146  illustrated in  FIG. 4B . 
     In other embodiments, any suitable mechanical or electrical mechanism may be used to block/interfere with the movement of the leg portion  156 . As an example, a mechanical lever may engage/disengage the leg portion  156 . As another example, an electromagnet, a motor and gear arrangement, etc. may be used to move the mechanical mechanism. Other arrangements are, of course, also possible. 
     Referring again to  FIGS. 2 ,  4 A and  4 B, the coil  150  may be energized (while the pin  153  is engaged with the leg portion  156 ) to cause the leg portion  154  to move such that the pole  141  touches the contacts  140 ,  142 , and the contactor  124  may be closed to precharge the system  110 . Once precharge of the system  110  is complete (e.g., when the voltage across the contactor  124  falls within an acceptable range and/or a predetermined period of time has based), the coil  152  may be energized to cause the spring-loaded pin  153  to disengage from the leg portion  156  and to allow the leg portion  156  to move such that the pole  145  touches the contacts  144 ,  146 . The contactor  124  may then be opened. Electrical power may thus flow from the power source  114  to loads electrically connected with the high voltage bus  116 . 
     Those of ordinary skill will recognize that any suitable and/or known controller(s) may be arranged with the system  110  in order to control the contactors  124 ,  126 . For example, one or more controllers may control the activation of the coils  150 ,  152  to achieve the sequential closing of the poles  141 ,  145  as described above. 
     While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

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