Patent Publication Number: US-9852857-B2

Title: Electrical switching apparatus and contact assembly therefor

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of, and claims priority under 35 U.S.C. §120 from U.S. patent application Ser. No. 14/558,921, filed on Dec. 3, 2014, and entitled “ELECTRICAL SWITCHING APPARATUS AND CONTACT ASSEMBLY THEREFOR,” the contents of which are incorporated by reference herein. 
    
    
     BACKGROUND 
     Field 
     The disclosed concept pertains generally to electrical switching apparatus such as for example, circuit breakers. The disclosed concept also relates to contact assemblies for electrical switching apparatus. 
     Background Information 
     Electrical apparatus, such as electrical switching apparatus or electrical meters used in power distribution systems, are often mounted on or within an electrical enclosure (e.g., without limitation, a panelboard; a load center; a meter breaker panel) either individually or in combination with other electrical meters or switchgear (e.g., without limitation, circuit switching devices and circuit interrupters such as circuit breakers, contactors, motor starters, motor controllers and other load controllers). Such circuit breakers are used to protect electrical circuitry from damage due to a trip condition, such as, for example, an overcurrent condition, an overload condition, an undervoltage condition, a relatively high level short circuit or fault condition, a ground fault or arc fault condition. 
     Molded case circuit breakers, for example, include at least one pair of separable contacts which are operated either manually by way of a handle disposed on the outside of the case, or automatically by way of a trip unit in response to the trip event. As the movable contacts move away from the stationary contacts, an electrical arc is formed in the space between the contacts. The arc provides a means for smoothly transitioning from a closed circuit to an open circuit, but produces a number of challenges to the circuit breaker designer. For example, extended arcing times result in excessive damage to the electrical contacts, particularly on higher amp rated devices. This damage causes elevated device resistance and subsequent failure due to exceeding temperature rise limits when conducting rated current. 
     There is thus room for improvement in electrical switching apparatus and in contact assemblies therefor. 
     SUMMARY 
     These needs and others are met by embodiments of the disclosed concept, which are directed to an electrical switching apparatus and contact assembly therefor. 
     In accordance with one aspect of the disclosed concept, a contact assembly is provided for an electrical switching apparatus having a housing. The contact assembly includes a movable arm having a movable contact, and an extension apparatus structured to be disposed on the housing. The extension apparatus includes a U-shaped link member having a first leg, a second leg, and a middle portion connecting the first leg to the second leg. The first leg at least partially extends into the movable arm. The second leg is structured to be disposed on the housing. 
     In accordance with another aspect of the disclosed concept, an electrical switching apparatus including a housing, at least one operating handle extending into the housing, at least one cradle member located in the housing, at least one operating mechanism coupled to the cradle member, and at least one of the aforementioned contact assemblies is provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
         FIG. 1  is an isometric view of an electrical switching apparatus, in accordance with an embodiment of the disclosed concept; 
         FIG. 2  is an elevation view of the electrical switching apparatus of  FIG. 1 , shown with the movable arm in the CLOSED position and with portions of the electrical switching apparatus removed to show hidden structures; 
         FIG. 3  is an elevation view of the electrical switching apparatus of  FIG. 2 , showing the movable arm in an open position; 
         FIG. 4  is an elevation view of the electrical switching apparatus of  FIG. 2 , showing the movable arm in an EXTENDED OPEN position; 
         FIG. 5  is an isometric view of a portion of the contact assembly for the electrical switching apparatus of  FIG. 4 ; 
         FIG. 6  is an isometric view of a portion of the housing for the electrical switching apparatus of  FIG. 4 ; 
         FIGS. 7A-7F  are different views of a trip cam for the electrical switching apparatus of  FIG. 1 ; 
         FIG. 8  is an elevation view of an indication assembly for the electrical switching apparatus of  FIG. 1 , shown in the loaded position; 
         FIG. 9  is an elevation view of the indication assembly of  FIG. 8 , shown in the unloaded position; 
         FIG. 10  is an isometric view of an operating handle assembly for the electrical switching apparatus of  FIG. 1 , showing the cradle member in the TRIPPED position; 
         FIG. 11  is an elevation view of the operating handle assembly of  FIG. 10  as employed in a portion of the electrical switching apparatus, showing the cradle member in the CLOSED position; and 
         FIG. 12  is an elevation view of the operating handle assembly of  FIG. 11 , showing the cradle member in the TRIPPED position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality). 
     As employed herein, the statement that two or more parts are “connected” or “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. 
     As employed herein, the statement that two or more parts or components “engage” one another shall mean that the parts touch and/or exert a force against one another either directly or through one or more intermediate parts or components. 
       FIG. 1  shows an electrical switching apparatus (e.g., without limitation, circuit breaker  2 ) in accordance with the disclosed concept. The example circuit breaker  2  includes a housing  10 , a number of operating handles (one operating handle  50  is indicated) extending into the housing  10 , and a number of trip cams (only one trip cam  200  is partially visible in  FIG. 1 ) located within the housing  10 . 
       FIGS. 2 through 4  show different views of the circuit breaker  2  with portions removed in order to see internal components. As seen, the circuit breaker  2  further includes a cradle member  40  located in and engaging the housing  10 , an operating mechanism (e.g., without limitation, spring  60 ) coupled to the cradle member  40 , and a contact assembly  100 . The circuit breaker  2  has a number of poles and a corresponding contact assembly (e.g., without limitation, substantially similar to or the same as the contact assembly  100 ) for each of the poles of the circuit breaker  2 . 
     Continuing to refer to  FIGS. 2 through 4 , the contact assembly  100  includes a stationary contact  102  located in the housing  10 , and a movable arm  110 . The movable arm  110  has a movable contact  112  structured to engage the stationary contact  102 . As will be discussed in greater detail hereinbelow, the movable arm  110  is structured to move between a CLOSED position ( FIG. 2 ) and an EXTENDED OPEN position ( FIG. 4 ). In order to maintain the movable arm  110  in the EXTENDED OPEN position ( FIG. 4 ), the contact assembly  100  advantageously further includes an extension apparatus  150  located on the housing  10 . 
     As seen in  FIG. 5 , the extension apparatus  150  includes a generally U-shaped link member  170  and an elongated extension  160  located on the movable arm  110 . The link member  170  is coupled to the elongated extension  160  and further structured to be located on and engage the housing  10 , as will be discussed below. The movable arm  110  includes a distal portion  120  located proximate the movable contact  112  and opposite the elongated extension  160 . Furthermore, the movable arm  110  has a cutout  122  located between the elongated extension  160  and the distal portion  120 . In operation, the operating handle  50  is structured to be located in the cutout  122 , as shown in  FIG. 4 . Additionally, the elongated extension  160  extends from the movable arm  110  proximate the cutout  122 . In the example non-limiting embodiment, the elongated extension  160  is integral with the movable arm  110 . Stated differently, the movable arm  110 , and thus the elongated extension  160 , preferably form a single unitary component composed of the same single piece of material (as opposed to a plurality of separate components being joined together). However, it will be appreciated that an elongated extension (not shown) may be an individual component separately coupled to a movable arm (not shown), without departing from the scope of the disclosed concept. 
     Continuing to refer to  FIG. 5 , the link member  170  includes a pair of opposing legs  172  (partially shown in hidden line drawing),  174  and a middle portion  176  generally normal to the legs  172 , 174  and connecting the leg  172  to the leg  174 . As seen, the elongated extension  160  includes a pair of spaced apart and opposing end portions  161 , 163 . Furthermore, the elongated extension  160  has an aperture  162  located proximate the end portion  161 . The leg  172  of the link member  170  at least partially extends into the aperture  162  of the elongated extension  160  in order to couple the link member  170  to the elongated extension  160 , and thus the movable arm  110 . Moreover, the movable contact  112  includes a contact surface  118  located in a plane (indicated generally as  118 - 1 ), and the elongated extension  160  has a longitudinal axis  160 - 1  at an angle  130  with the plane  118 - 1 . As seen, the angle  130  is preferably greater than 90 degrees. It will be appreciated that when the movable arm  110  is in the EXTENDED OPEN position, the extension apparatus  150 , and particularly the configuration of the elongated extension  160  and its relation with the link member  170 , and internal portion  14  of housing  10 , advantageously enables the movable arm  110  to be maintained in the EXTENDED OPEN position ( FIG. 4 ), as will be discussed in greater detail hereinbelow. It will also be appreciated that an extension apparatus (not shown) may have any known or suitable alternative shape and/or configuration to perform the desired function of maintaining the movable arm  110  in an EXTENDED OPEN position. 
       FIG. 6  shows a portion of the example housing  10 . As seen, the housing  10  includes a wall portion  12  and an internal portion  14  adjacent the wall portion  12 . The internal portion  14  has a slot  20  that has a pair of opposing and spaced apart end portions  22 , 24  and a center portion  26  located generally midway between the end portions  22 , 24 . The end portion  22  is adjacent the wall portion  12  and the end portion  24  is internal with respect to the wall portion  12 . 
     Referring again to  FIG. 2 , in which the movable arm  110  is in the CLOSED position, the leg  174  of the link member  170  is located on the housing  10  proximate the center portion  26  of the slot  20  (i.e., spaced from the end portion  22 ). Although the leg  174  partially extends into the slot  20 , it is within the scope of the disclosed concept for an internal portion (not shown) to alternatively include a slot for a leg (not shown) to extend entirely therethrough. Additionally, the middle portion  176  of the link member  170  has a longitudinal axis  176 - 1  that is generally normal to the plane  118 - 1  of the contact surface  118 , as shown. 
     Furthermore,  FIG. 2  shows the operating handle  50  is in an ON position. Responsive to the operating handle  50  moving from the ON position toward an OFF position ( FIGS. 3 and 4 ), the movable arm  110  moves from the CLOSED position ( FIG. 2 ) toward the EXTENDED OPEN position ( FIG. 4 ). It will further be appreciated that responsive to the movable arm  110  moving from the CLOSED position ( FIG. 2 ) toward the EXTENDED OPEN position ( FIG. 4 ), the cradle member  40  remains substantially stationary. In other words, the example extension apparatus  150  is significantly advantageous when the operating handle  50  is manually moved between ON and OFF positions. 
       FIG. 3  shows the movable arm  110  in an open position. For ease of illustration and purposes of discussion, the contact assembly  100  is illustrated in  FIG. 3  without the link member  170  ( FIGS. 2, 4 and 5 ). As will be discussed below, by incorporating the link member  170  with the elongated extension  160 , the movable arm  110  is advantageously able to be maintained in the EXTENDED OPEN position ( FIG. 4 ). Additionally, in the open position of  FIG. 3 , the spring  60  is in a static position in which it does not tend to cause the movable arm  110  to rotate one direction or the other. Furthermore, as seen, the movable contact  112  is spaced a distance  114  from the stationary contact  102 . 
       FIG. 4  shows the movable arm  110  in the EXTENDED OPEN position. In this position, the movable contact  112  is spaced a distance  116  from the stationary contact  102 . The distance  116  ( FIG. 4 ) is greater than the distance  114  ( FIG. 3 ). In other words, the movable contact  112  is spaced a farther distance from the stationary contact  102  in the EXTENDED OPEN position than in the open position of  FIG. 3 . Additionally, in the EXTENDED OPEN position ( FIG. 4 ), the elongated extension  160  extends from proximate the cutout  122  toward the stationary contact  102 , and the middle portion  176  generally overlies and is parallel to the slot  20 . 
     Furthermore, responsive to the operating handle  50  moving from the ON position ( FIG. 2 ) to the OFF position ( FIG. 4 ), the leg  174  of the link member  170  slides in the slot  20  from proximate the center portion  26  to the end portion  22  and exerts a force on the wall portion  12  of the housing  10 . In this manner, the movable arm  110  to be maintained in the EXTENDED OPEN position ( FIG. 4 ). Thus, responsive to the movable arm  110  moving from the CLOSED position ( FIG. 2 ) toward the EXTENDED OPEN position ( FIG. 4 ), the end portion  163  of the elongated extension  160  moves toward the leg  174  of the link member  170 , and the leg  174  of the link member  170  moves away from the distal portion  120  of the movable arm  110 . 
     Moreover, as the operating handle  50  is rotated toward the OFF position ( FIGS. 3 and 4 ), the stored energy of the spring  60  initially forces the movable arm  110  to move from the CLOSED position ( FIG. 2 ) toward the EXTENDED OPEN position ( FIG. 4 ). After the spring  60  passes its static position (also the OFF position) ( FIG. 3 ), inertia allows the movable arm  110  to continue rotating to the EXTENDED OPEN position ( FIG. 4 ). Typically, the movable arm  110  would rotate from the EXTENDED OPEN position ( FIG. 4 ) back toward the CLOSED position ( FIG. 2 ), and continue to oscillate until it became steady in the open position shown in  FIG. 3 . However, when the movable arm  110  initially reaches the EXTENDED OPEN position ( FIG. 4 ), the leg  174  of the link member  170  engages and substantially presses against the wall portion  12  of the housing  10  in order to maintain the movable arm  110  in the EXTENDED OPEN position ( FIG. 4 ). The wall portion  12  exerts an opposing force on the link member  170 , which in turn exerts a moment on the movable arm  110  to advantageously maintain the movable arm  110  in the EXTENDED OPEN position ( FIG. 4 ). Thus, the stored energy of the spring  60  forces the movable arm  110  to the EXTENDED OPEN position ( FIG. 4 ) and the extension apparatus  150  in turn advantageously maintains the movable arm  110  in the EXTENDED OPEN position ( FIG. 4 ). Stated differently, when the movable arm  110  is in the EXTENDED OPEN position, the extension apparatus  150  retains the movable arm  110  in the EXTENDED OPEN position until an operator moves the operating handle  50  from the OFF position toward the ON position, which causes the movable arm  110  to be released from the EXTENDED OPEN position and move toward the CLOSED position. 
     It is well known that a circuit breaker having minimal contact separation while moving from ON to OFF positions will have extended arcing times. This in turn results in excessive damage to the electrical contacts, which corresponds to elevated resistance and subsequent failure due to exceeding temperature rises when conducting current. Thus, it will be appreciated that the stationary contact  102  and the movable contact  112  are significantly well protected. Specifically, responsive to the operating handle  50  moving from the ON position ( FIG. 2 ) to the OFF position ( FIG. 4 ), the movable contact  112  moves past the open position shown in  FIG. 3  to the EXTENDED OPEN position ( FIG. 4 ), and is maintained at a farther distance from the stationary contact  102  (i.e., the distance  116  is greater than the distance  114 ). Thus, arcing times, device resistance, and temperature rises are all decreased by employing the extension apparatus  150 . Additionally, problematic oscillations associated with prior art equilibrium open positions, which result in momentary reduced contact gaps, are eliminated. In this manner, the circuit breaker  2 , particularly the stationary contact  102  and the movable contact  112 , are advantageously well protected. 
     Accordingly, it will be appreciated that the disclosed concept provides for an improved (e.g., without limitation, reduced electrical resistance and increased protection from damage due to temperature rises) electrical switching apparatus (e.g., without limitation, circuit breaker  2 ), and contact assembly therefor, which among other benefits, provides additional separation for electrical contacts (e.g., without limitation, stationary contact  102  and movable contact  112 ). 
       FIGS. 7A-7F  show different views of the trip cam  200  for the circuit breaker  2  ( FIGS. 1-4 ). In the illustrated embodiment, the trip cam  200  includes a generally cylindrical-shaped mounting portion  210 , a transfer leg  212 , a driving leg  214 , and a trip indicator leg  220 . Although the circuit breaker  2  ( FIGS. 1-4 ) has been described hereinabove in association with the operating handle  50  being manually moved from ON to OFF positions, when the circuit breaker  2  ( FIGS. 1-4 ) does undergo a tripping event (e.g., without limitation, an overcurrent condition), the transfer leg  212  cooperates with each of the poles of the circuit breaker  2  ( FIGS. 1-4 ) in a manner generally well known in the art. Additionally, during the tripping operation, the cradle member  40  ( FIGS. 2-4 ) drives the driving leg  214 , as will be discussed in greater detail hereinbelow. 
     Referring to  FIG. 7B , the transfer leg  212  extends from the mounting portion  210  in a direction  213  and the driving leg  214  extends from the mounting portion  210  in a direction  215 . Furthermore, the trip indicator leg  220  includes a base portion  222  that extends from the mounting portion  210  in a direction  223  generally opposite the direction  215 . This position of the trip indicator leg  220  advantageously enables the trip cam  200  to provide a visual indication of circuit status within the circuit breaker  2  ( FIGS. 1-4, 11 and 12 ), as will be discussed in greater detail hereinbelow. 
     Continuing to refer to  FIGS. 7A and 7B , the base portion  222  includes a pair of opposing and spaced apart end portions  224 , 226 . The end portion  224  extends from the mounting portion  210  and the trip indicator leg  220  further has a trip flag  228  that extends from the end portion  226  at an angle  229 . As seen, the angle  229  is preferably less than 100 degrees. The trip flag  228  has a generally rectangular-shaped trip indicating surface  230  ( FIG. 7A ), the function of which will be described below. The trip indicator leg  220  further includes a support portion  232  that extends from the base portion  222  and further extends from the mounting portion  210  in a direction  233  ( FIG. 7C ) generally opposite the direction  213 . During the tripping operation, responsive to the cradle member  40  driving the driving leg  214 , the trip cam  200  rotates about the mounting portion  210 . Because of the relatively high rotational velocity of the trip cam  200 , the support portion  232  advantageously provides support for the trip indicator leg  220 . 
     The support portion  232  includes a pair of generally triangular-shaped parallel surfaces  234 , 236 . The triangular-shaped surfaces  234 , 236  substantially extend along the base portion  222  as well as the mounting portion  210  (see  FIGS. 7A-7C ). Thus, support for the trip indicator leg  220  is advantageously further increased. The triangular-shaped surface  234  is opposite and spaced apart from the triangular-shaped surface  236 . Of course, it will be appreciated that a support portion (not shown) may have any known or suitable alternative shape and/or configuration and/or interaction with the base portion  222  and the mounting portion  210  in order to perform the desired function of supporting the trip indicator leg  220  during the tripping operation. Additionally, the mounting portion  210  includes a pair of generally parallel end surfaces  240 , 242  and the base portion  222  extends from proximate the end surface  240  to proximate the end surface  242 . Thus, there is a relatively strong connection between the base portion  222  and the mounting portion  210 . 
     Furthermore, the base portion  222  includes a pair of generally rectangular-shaped parallel side surfaces  244 , 246 . The side surface  244  extends from proximate the end surface  242  of the mounting portion  210 . The side surface  246  extends from proximate the end surface  240  of the mounting portion  210  and is opposite and spaced apart from the side surface  244 . As seen in  FIG. 7D , the surfaces  234 , 236 , 240 , 242 , 244 , 246  are generally parallel to each other. Additionally, the support portion  232  is located generally midway between the end surfaces  240 , 242 . In this manner, as the trip cam  200  rotates during the tripping operation, the structure of the trip indicator leg  220  significantly enables the trip indicator leg  220  to remain relatively stable. 
       FIGS. 8 and 9  show an indication assembly  300  for the circuit breaker  2  ( FIGS. 1-4 ). The indication assembly  300  includes the cradle member  40  and the trip cam  200 . More specifically, the indication assembly  300  is structured to move between a loaded position ( FIG. 8 ) corresponding to the contacts  102 , 112  ( FIGS. 2-4 ) being CLOSED and an unloaded position ( FIG. 9 ) corresponding to the contacts  102 , 112  ( FIGS. 2-4 ) in the different position shown, after having TRIPPED OPEN. 
     Furthermore, the cradle member  40  includes a hook portion  42 , a protrusion  44  and an extension arm  46 . The protrusion  44  is located between the hook portion  42  and the extension arm  46 . The hook portion  42  is opposite the extension arm  46  and engages the housing  10 . As seen, responsive to the indication assembly  300  moving from the loaded position ( FIG. 8 ) toward the unloaded position ( FIG. 9 ), the protrusion  44  drives the driving leg  214  of the trip cam  200 . As will be discussed below in connection with  FIGS. 11 and 12 , it follows that responsive to the driving leg  214  being driven by the cradle member  40 , the trip indicator leg  220  rotates about the mounting portion  210 . 
       FIGS. 11 and 12  show different views of the indication assembly  300  employed in a portion of the circuit breaker  2 . Specifically,  FIG. 11  shows the circuit breaker  2  with the indication assembly  300  in the loaded position and  FIG. 12  shows the circuit breaker  2  with the indication assembly  300  in the unloaded position. The housing  10  includes a generally planar external surface  16  (see also, for example,  FIGS. 1 and 6 ) that has a window  18 . Although only the window  18  and the indication assembly  300  are described herein, it will be appreciated that the circuit breaker  2  includes a plurality of windows and a plurality of indication assemblies for each of the poles. It will further be appreciated that responsive to any one of the indication assemblies (only one indication assembly  300  is shown) moving from the loaded position to the unloaded position, each of the other indication assemblies also moves from a corresponding loaded position to a corresponding unloaded position. 
     The side surfaces  244  (see  FIGS. 7A and 7D  for side surface  246 ) and the triangular-shaped surfaces  234  (see  FIGS. 7A and 7D  for triangular-shaped surface  236 ) of the trip cam  200  are generally normal to the external surface  16 . As seen, when the indication assembly  300  is in the unloaded position ( FIG. 12 ), the direction  233  is generally parallel to the extension arm  46  and is substantially normal to the external surface  16 . 
     Continuing to refer to  FIG. 11 , when looking through the window  18  at an observation point  19  (i.e., an observation point directly above and looking into the window  18 ), the trip indicating surface  230  is not visible. Responsive to the indication assembly  300  moving from the loaded position ( FIGS. 8 and 11 ) toward the unloaded position ( FIGS. 9 and 12 ), the trip indicating surface  230  moves from a position where it is not visible through the window  18  from the observation point  19 , toward a position where it is substantially located in the window  18 . In this position (i.e., the unloaded position), the trip indicating surface  230  is visible through the window  18  from the observation point  19 . 
     Stated differently, when the indication assembly  300  is in the unloaded position, an operator looking through the window  18  would observe the trip indicating surface  230 . Thus, in the unloaded position the trip indicating surface  230  substantially faces the observation point  19  and there is nothing (e.g., housing  10 ) between the trip indicating surface  230  and the observation point  19 . Stated differently, in the unloaded position light is able to pass directly from the observation point  19  to the trip indicating surface  230 . By contrast, when the indication assembly  300  is in the loaded position, the operator looking through the window  18  from the observation point  19  would not be able to see the trip indicating surface  230 . Specifically, in the loaded position the trip indicating surface  230  substantially faces the housing  10 , which is located between the observation point  19  and the trip indicating surface  230 . Thus, in the loaded position light is not able to pass directly from the observation point  19  to the trip indicating surface  230 . 
     Because the loaded position corresponds to the contacts  102 , 112  ( FIGS. 2-4 ) being CLOSED and the unloaded position corresponds to the contacts  102 , 112  ( FIGS. 2-4 ) having TRIPPED OPEN, circuit status within the circuit breaker  2  is advantageously able to be determined by employing the trip indicator leg  220 . Specifically, a visible trip indicating surface  230  from the observation point  19  signals that the contacts  102 , 112  ( FIGS. 2-4 ) have TRIPPED OPEN. The absence of the trip indicating surface  230  from the observation point  19  signals that the contacts  102 , 112  ( FIGS. 2-4 ) are CLOSED, or that the circuit breaker  2  has been manually opened. While the disclosed concept has been described in association with the base portion  222  extending in the direction  223  in order to have a visible trip indicating surface  230  when the contacts  102 , 112  ( FIGS. 2-4 ) have TRIPPED OPEN, it will be appreciated that a base portion (not shown) may extend in a suitable alternative direction without departing from the scope of the disclosed concept, so long as different indications correspond to different positions (i.e., CLOSED or manually being opened versus TRIPPED OPEN) of the contacts  102 , 112  ( FIGS. 2-4 ). Additionally, the disclosed concept has been described in association with the generally rectangular-shaped trip indicating surface  230  and corresponding window  18 . However, it will be appreciated that a trip indicating surface (not shown) and corresponding window (not shown) may have any known or suitable alternative shape and/or configuration in order to perform the desired function of enabling circuit status to be visually determined. 
     As an additional benefit, by employing the trip indicator leg  220  in conjunction with the trip cam  200 , manufacturing is able to be simplified. More specifically, separate assemblies and/or mechanisms which provide visual indication of circuit status (not shown) no longer need to be employed because the separate function of indication of circuit status has been combined with the component (e.g., trip cam) whose primary function is to trip all poles of an electrical switching apparatus. This advantageously corresponds to a reduction in device cost and assembly time, as well as a more efficient use of available space. Additionally, the trip cam  200  is preferably a single piece of material (e.g., without limitation, an injection molded piece), thus further simplifying manufacturing and reducing cost. 
     Accordingly, it will be appreciated that the disclosed concept provides for an improved (e.g., without limitation, less expensive, easier to assemble, more compact) electrical switching apparatus (e.g., without limitation, circuit breaker  2 ), and indication assembly  300  and trip cam  200  therefor, which among other benefits, combines the functions of providing visual indication of circuit status with a means for tripping all poles of the circuit breaker  2 . 
     Referring again to  FIGS. 7A and 7B , the mounting portion  210  includes a first region  212 - 1 , a second region  260 - 1  located generally opposite the first region  212 - 1 , and a third region  214 - 1  located generally between the first region  212 - 1  and the second region  260 - 1 . Each of the regions  212 - 1 , 214 - 1 , 260 - 1  generally extends from the end surface  240  of the mounting portion  210  to the end surface  242  of the mounting portion  210 . The transfer leg  212  extends from the first region  212 - 1  and the driving leg  214  extends from the third region  214 - 1 . Additionally, the trip cam  200  further includes a partially cylindrical-shaped operating handle protrusion  260  that extends from the second region  260 - 1  and is structured to engage the operating handle  50  ( FIGS. 1-4 and 10-12 ). It will be appreciated that a trip cam may include either one of, or both of the trip indicator leg  220  and the operating handle protrusion  260 , without departing from the scope of the disclosed concept. As will be discussed below, the operating handle protrusion  260  advantageously enables the cradle member  40  to cooperate with the operating handle  50 . 
     The operating handle protrusion  260  includes a pair of spaced apart generally planar side surfaces  262 , 264  and a curved surface  266  connecting the first side surface  262  to the second side surface  264 . The side surfaces  262 , 264  are located between and are preferably parallel to each of the end surfaces  240 , 242  of the mounting portion  210 . As seen in  FIG. 7B , the operating handle protrusion  260  substantially extends from the second region  260 - 1  in a direction  261  generally normal to the direction  215 . Additionally, referring to  FIGS. 7E and 7F , the operating handle protrusion  260  extends from proximate the end surface  240  to generally midway between the end surfaces  240 , 242 . In this position, the operating handle protrusion  260  is advantageously able to substantially align with and engage a portion of the operating handle  50 , as will be discussed in greater detail hereinbelow. 
       FIG. 10  shows an isometric view of an example operating handle assembly  400  for the circuit breaker  2  ( FIGS. 1-4 ), in accordance with the disclosed concept. It will be appreciated that the circuit breaker  2  may include a plurality of operating handle assemblies (i.e., substantially similar to or the same as the operating handle assembly  400 ) for each of the poles of the circuit breaker  2 . As seen, the example operating handle assembly  400  includes the cradle member  40 , the trip cam  200 , and the operating handle  50 . 
       FIGS. 11 and 12  show different views of the operating handle assembly  400  installed in a portion of the circuit breaker  2 . More specifically, the cradle member  40  is structured to move from a CLOSED position ( FIG. 11 ) corresponding to the contacts  102 , 112  ( FIGS. 2-4 ) being CLOSED to a TRIPPED position ( FIG. 12 ) corresponding to the contacts  102 , 112  ( FIGS. 2-4 ) having TRIPPED OPEN. As will be discussed below, by employing the operating handle protrusion  260 , the operating handle  50  always moves from an ON position to a TRIPPED position after the circuit breaker  2  ( FIGS. 2-4, 11 and 12 ) experiences a tripping event. 
     As seen in  FIG. 10 , the operating handle  50  includes an engaging surface  52  structured to engage the curved surface  266  of the operating handle protrusion  260 . Because the operating handle protrusion  260  extends from proximate the end surface  240  to generally midway between the end surfaces  240 , 242  (see for example  FIGS. 7E and 7F ), it will be appreciated that in operation, the engaging surface  52  is located between the end surface  240  and midway between the end surfaces  240 , 242 . Furthermore, the engaging surface  52  is substantially normal to each of the first side surface  262  and the second side surface  264 . 
     Referring to  FIG. 11 , in which the cradle member  40  is in the CLOSED position, the operating handle protrusion  260  is spaced from the engaging surface  52 . In this position, the operating handle  50  is at an angle  50 - 1  with the external surface  16  of the housing  10 , as shown. Responsive to the cradle member  40  moving from the CLOSED position ( FIG. 11 ) toward the TRIPPED position ( FIG. 12 ), the operating handle protrusion  260  rotates about the mounting portion  210 . In this manner, the space between the operating handle protrusion  260  and the engaging surface  52  decreases until the operating handle protrusion  260  engages the engaging surface  52  of the operating handle  50 . At this point, because the trip cam  200  is rotating relatively quick, and because of the relative position of the operating handle protrusion  260  (i.e., extending in the direction  261 ), the operating handle protrusion  260  gives the operating handle  50  a “kick” and drives the operating handle  50  from the ON position to the TRIPPED position. It will however be appreciated that an operating handle protrusion (not shown) in accordance with an alternative embodiment of the disclosed concept may extend in any suitable alternative direction, and/or engage any suitable alternative surface (not indicated) other than the engaging surface  52 , and/or be located in any suitable alternative position relative to the mounting portion  210 , in order to perform the desired function of driving the operating handle  50  from the ON position to the TRIPPED position. 
       FIG. 12  shows the operating handle assembly  400  in a position in which the operating handle protrusion  260  is engaging the engaging surface  52  of the operating handle  50  and has caused the operating handle  50  to rotate to the TRIPPED position. Specifically, the operating handle  50  is at an angle  50 - 2  with the external surface  16  of the housing  10 , as shown. The angle  50 - 2  is greater than the angle  50 - 1  ( FIG. 11 ). 
     The operating handle protrusion  260  advantageously imparts an additional force to the operating handle  50  during the tripping operation that is significant enough to always cause the operating handle  50  to rotate to the TRIPPED position. In this manner, frictional forces within the circuit breaker  2  are no longer able to cause the operating handle  50  to get stuck during a tripping operation. Thus, when the circuit breaker  2  undergoes a tripping event (e.g., without limitation, an overcurrent condition), the operating handle  50  always moves from the ON position to the TRIPPED position, advantageously providing a more reliable means for an operator to know whether a circuit breaker has tripped or not, overcoming the disadvantages of known circuit breakers (not shown) which have operating handles (not shown) that often get stuck during a tripping operation due to frictional forces. 
     Additionally, while the disclosed concept has been described in association with the partially cylindrical-shaped operating handle protrusion  260 , it will be appreciated that an operating handle protrusion (not shown) may have any known or suitable alternative shape, and/or configuration with respect to a mounting portion (not shown), in order to perform the desired function of driving the operating handle  50  from the ON position to the TRIPPED position in response to a tripping event. Furthermore, while the trip cam  200  is preferably made of a single piece of material (e.g., without limitation, an injection molded piece), it will be appreciated that an operating handle protrusion (not shown) may be a separate component coupled to a trip cam (not shown), without departing from the scope of the disclosed concept. 
     Accordingly, it will be appreciated that the disclosed concept provides for an improved (e.g., without limitation, more reliable in terms of correlation between operating handle position and electrical contact position) electrical switching apparatus (e.g., without limitation, circuit breaker  2 ), and operating handle assembly  400  and trip cam  200  therefor, which among other benefits, provides a mechanism to ensure that the operating handle  50  always rotates to the TRIPPED position during after experiencing a tripping event. 
     While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.