Patent Publication Number: US-6714116-B1

Title: Circuit breaker switch

Description:
The invention generally relates to the field of circuit breakers, and particularly relates to the field of re-settable circuit breaker switches that may be economically and efficiently produced. 
     BACKGROUND OF THE INVENTION 
     Circuit breaker switches generally include a reactive element (for example a bimetallic conductive material) that is in the path of the current passing through the breaker when the switch is in the on position. The reactive element responds to an excess current or voltage charge by changing a property of the reactive element such as its shape, and thereby disrupting the path of the current through the breaker. 
     For example, U.S. Pat. No. 5,491,460 discloses a switch that includes a thermal triggering element that cooperates with other portions of the circuit in providing overcurrent protection, and U.S. Pat. Nos. 5,847,638; and 5,892,426 disclose switches that specifically include a bimetallic element that changes shape to provide circuit protection against excess current. Further, U.S. Pat. No. 5,539,371 discloses a circuit breaking switch that includes an alloy blade  170  that changes its curvature responsive an current overload condition. 
     Convention circuit breaker switches, however, typically require numerous small parts that must be assembled accurately, and sometimes require minor adjustments via set screws etc. to function optimally. For example, the breaking switch disclosed in U.S. Pat. No. 5,539,371 includes an adjusting screw that may be rotated to adjust the arch of a spring blade. 
     There is a need for a circuit breaker switch that is relatively inexpensive to produce yet operates efficiently. 
     There is further a need for a circuit breaker switch that provides an indication that the breaker has tripped. 
     There is further a need for a c circuit breaker switch that may be easily re-set. 
     SUMMARY OF THE INVENTION 
     A circuit breaker switch is disclosed, including a rocker, an actuator, and a dielectric separator element. The rocker is positionable between a first on position and a second off position. The actuator element is coupled to the rocker such that it causes a first electrically conductive contact portion to move into contact with a second electrically conductive contact portion when the rocker is in the on position. The dielectric separator element is urged between the first and second electrically conductive contact portions in the event of excess current being passed between the first and second electrically conductive contact portions. 
     In various embodiments, the switch further includes a trip indicator that is coupled to the dielectric separator element such that the trip indicator provides a visual indication that excess current has been passed between the first and second electrically conductive contact portions. In further embodiments, the switch may be reset by depressing the trip indicator. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following detailed description of the illustrated embodiments may be further understood with reference to the accompanying drawings in which: 
     FIG. 1 shows an illustrative isometric view of a circuit breaker switch of the invention; 
     FIG. 2A shows an illustrative side sectional view of the circuit breaker switch shown in FIG. 1 in the off position taken along line A—A thereof; 
     FIG. 2B shows an illustrative end sectional view of the circuit breaker switch shown in FIG. 1 in the off position taken along line B—B thereof; 
     FIG. 2C shows an illustrative bottom sectional view of the circuit breaker switch shown in FIG. 1 in the off position taken along line C—C thereof; 
     FIG. 3A shows an illustrative side sectional view of the circuit breaker switch shown in FIG. 1 in the on position taken along line A—A thereof; 
     FIG. 3B shows an illustrative end sectional view of the circuit breaker switch shown in FIG. 1 in the on position taken along line B—B thereof; 
     FIG. 3C shows an illustrative bottom sectional view of the circuit breaker switch shown in FIG. 1 in the on position taken along line C—C thereof; 
     FIG. 4A shows an illustrative side sectional view of the circuit breaker switch shown in FIG. 1 in the trip position taken along line A—A thereof; 
     FIG. 4B shows an illustrative end sectional view of the circuit breaker switch shown in FIG. 1 in the trip position taken along line B—B thereof; and 
     FIG. 4C shows an illustrative bottom sectional view of the circuit breaker switch shown in FIG. 1 in the trip position taken along line C—C thereof. 
     The drawings are for illustrative purposes only and are not to scale. 
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     As shown in FIG. 1, a circuit breaker switch  10  in accordance with an embodiment of the invention includes a housing  12  that includes a pair of resilient retainer portions  14  for mounting the circuit breaker switch  10  and a top portion  16 . The circuit breaker switch lo also includes an ON/OFF rocker  18  and a trip indicator  20  that are exposed through openings in the top portion  16  of the housing  12 . 
     Generally, during use an electrically conductive path may be established between a line terminal  22  and a load terminal  24  by positioning the ON/OFF rocker  18  to the ON position. If the circuit breaker switch  10  is overloaded and trips, then the trip indicator  20  will protrude through the top portion  16  of the housing  12 . The switch  10  may then be reset by depressing the trip indicator  20  as discussed below in further detail. FIGS. 2A-2C show the switch  10  in the OFF position, FIGS. 3A-3C show the switch  10  in the ON position, and FIGS. 4A-4C show the switch  10  in the trip position. 
     As shown in FIG. 2A, the rocker  18  is pivotally coupled to an actuator block  26  such that as the rocker  18  is moved from the OFF position (as shown in FIG. 2A) to the ON position (as shown in FIG.  3 A), the lower portion of the block  26  is wedged between the adjacent inner wall  30  of the housing  12  and a spring plate  28 . As shown in FIG. 2B, the spring plate  28  includes a first electrically conductive contact element  32 , and as the block  26  is wedged between the inner wall  30  of the housing  12  and the spring plate  28 , the contact element  32  is urged to move against a second electrically conductive contact element  34  as shown in FIG.  3 B. The second contact element  34  is mounted on a bimetallic strip  36  that is electrically coupled to the line terminal  22  as shown in FIG.  2 C. The spring plate  28  is electrically coupled to the load terminal  24  as shown in FIG. 2C, and when the first and second contact elements  32  and  34  are in contact with one another as shown in FIGS. 3A-3C, electrical conductivity is established between the line terminal  22  and the load terminal  24 . 
     The switch  10  also includes a rotating dielectric lever  38  that is pivotally coupled to an indicator lever  40 , the top of which includes the indicator  20 . The switch  10  also includes bias spring  42  that urges the lower portion of the lever  38  against the second contact element  34  as shown in FIGS. 2B and 3B. If the breaker switch  10  is overcharged, the bimetallic strip  36  bends responsive to the excess current causing the second contact element  34  to be drawn away from the first contact element  32  as shown in FIG.  4 C. The lower portion of the lever  38  is then urged between the contacts  32  and  34  as shown in FIGS. 4B and 4C ensuring that the elements  32  and  34  are not in electrical contact with one another. 
     As shown in FIG. 4A, the rotation of the dielectric lever  38  causes the indicator lever  40  to move upward through the top portion  167  of the housing  12 . The indicator  20  is included in the top of the lever  40  and provides a visual indication that the breaker has tripped. The switch  10  may then be turned off by moving the rocker to the OFF position as shown in FIG. 2A, and the switch may be reset by depressing the indicator  20  back into the top portion  16  of the housing  12 . This will cause the dielectric lever to return to the position shown in FIGS. 2B,  2 C,  3 B and  3 C. 
     Circuit breaker switches such as that disclosed above may be efficiently and economically produced due to the relatively few number of parts required. Those skilled in the art will appreciate that modifications and variations may be made to the above disclosed embodiments without departing from the spirit and scope of the invention.