Abstract:
A molded case circuit breaker assembly using auxiliary switches to perform indication and control functions. The circuit breaker assembly having at least one pole comprising a stationary and a moveable contact where the moveable contact is connected to a moveable contact arm which is activated by a spring mechanism. The spring mechanism is affixed to an operating handle. A trip device, housed in a mid-cover of the molded case, separates the stationary and moveable contacts when a fault is sensed. The mid-cover comprises at least one auxiliary switch compartment, where a single auxiliary switch compartment is capable of housing multiple compatible auxiliary switches.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to the mounting of auxiliary switches in a molded case circuit breaker and, more particularly, to customizing a molded case circuit breaker by providing a flexible packaging arrangement for mounting various types of auxiliary switches in a mid-cover of the molded case circuit breaker. 
     As electrical power distribution systems become more sophisticated, increasing demands are placed on circuit breakers to perform collateral functions in addition to their primary function of circuit protection. The circuit breaker can be customized for use in various applications. The customization is achieved by installing one or more auxiliary switches in the circuit breaker. Conventionally, the auxiliary switch is utilized for indicating the open or closed position of a pair of contacts, or for indicating tripping on a fault, or for any other control or indication function. The auxiliary switch cooperates electrically or mechanically with components of the circuit breaker. 
     Dependant on the individual demands of the circuit breaker, one or more auxiliary switches are used. When used in a molded case circuit breaker, the space available to accommodate these auxiliary switches is at a premium. Isolation of the auxiliary switches from live breaker parts in a circuit breaker case is essential for field installation of the auxiliary switch and also to maintain the integrity of the circuit breaker. 
     SUMMARY OF THE INVENTION 
     It is therefore desirable to provide a safe and flexible mounting method for installing auxiliary switches in the molded case circuit breaker. By installing the auxiliary switches in the circuit breaker one can customize the circuit breaker to meet individual applications. 
     The use of one compartment to house multiple auxiliary switches provides flexibility in the mounting of the auxiliary switches. To secure the auxiliary switch in its position within the compartment, a series of teeth are formed on both the auxiliary switch and on the auxiliary switch mating surface located on the mid-cover. The auxiliary switch is snapped into place, and the auxiliary unit teeth and the mid-cover teeth mesh, thereby preventing any rotational movement of the secured auxiliary switch. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring now to the drawings wherein like elements are numbered alike in the several FIG. s: 
     FIG. 1 is a left perspective view of a molded case circuit breaker comprising a base, a mid-cover and a top cover of the present invention; 
     FIG. 2 is a top view of the circuit breaker mid-cover of FIG. 1; 
     FIG. 3 is a left perspective view of the molded case circuit breaker of FIG. 1 with the top cover removed and a quantity of auxiliary switches installed; 
     FIG. 4 is a left perspective view of a portion of the circuit breaker mid-cover of the preferred embodiment of the present invention; 
     FIG. 5 is a top view of the circuit breaker mid-cover of FIG. 4 with a quantity of auxiliary switches installed; 
     FIG. 6 is a rear perspective view of an auxiliary switch of FIG. 4; 
     FIG. 7 is a side view of the auxiliary switch of FIG. 6 shown during installation into an auxiliary switch compartment; 
     FIG. 8 is a bottom view of the auxiliary switch of FIG. 6; 
     FIG. 9 is a left perspective view of the auxiliary switch of FIG. 6; 
     FIG. 10 is a top view of the circuit breaker mid-cover of a second embodiment of the present invention; 
     FIG. 11 is a left perspective view of an auxiliary switch compartment of the circuit breaker mid-cover of FIG. 10; 
     FIG. 12 is a left perspective view of a bottom mounting rail for use with the auxiliary switch compartment of FIG. 10; 
     FIG. 13 is a left perspective view of a top mounting rail for use with the auxiliary switch compartment of FIG. 10; 
     FIG. 14 is a side view of an auxiliary switch for use with the circuit breaker mid-cover of FIG. 10; and 
     FIG. 15 is a side view of the auxiliary switch of FIG.  14 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a molded case circuit breaker  10  of the present invention. The present invention as described, pertains to a three-pole circuit breaker, however, other circuit breaker assemblies can utilize the present invention. The illustrations are used to aid in describing the invention and are not meant to be limiting. The molded case circuit breaker  10  comprises a molded case  14  having a base  16 , a mid-cover  18  and a top cover  20 . 
     Referring to FIG. 2, electrical connection with a plurality of current carrying components (not shown), which are located in the base  16 , is made by a plurality of load terminal straps (not shown) and a plurality of line terminal straps (not shown), which extend from the load side  22  and the line side  24  of the circuit breaker. As is known in the art, each pole  12  of the circuit breaker  10  comprises a stationary contact and a movable contact, with the moveable contact being fastened to a moveable contact arm. The circuit breaker  10  also comprises a spring mechanism for actuating the moveable contact arm. As shown in FIG. 1, an electronic trip unit  26 , contained in a recess of the mid-cover  18  controls the current carrying components of the circuit breaker  10 . A circuit breaker operating handle (not shown) extends up from an access slot  28  formed in the top cover  20  and is connected to the spring mechanism. 
     Referring to FIG. 3, when the individual application of the circuit breaker  10  mandates customization, at least one auxiliary switch  30  is installed in the circuit breaker  10 . Typically the auxiliary switch  30  is utilized for indicating the open or closed position of a pair of contacts, or for indicating tripping on a fault, or for any other control or indication function. The auxiliary switch  30  can be a unique right auxiliary switch  32  or a unique left auxiliary switch  34  configured to be a normally open or a normally closed switch. Other switches that can be installed in the circuit breaker  10 , include but are not limited to, a unique bell alarm mechanism switch  33  and a unique bell alarm trip switch  35 . 
     Referring to FIG. 4, the mid-cover  18  comprises a right auxiliary switch compartment  36  and a left auxiliary switch compartment  38 . The right and left auxiliary switch compartments  36 ,  38 , are formed integral with the mid-cover  18 . As best shown in FIG. 4, the right and left auxiliary compartments  36 ,  38 , further comprise a front mounting surface  40 , a rear mounting surface  42  and a bottom surface  44 . The right and left auxiliary switch compartments  36 ,  38  generally exist as recesses in the mid-cover  18 . The bottom surfaces  44  of the compartments  36 ,  38  are perpendicular to the front and rear mounting surfaces  40 ,  42 . Where the bottom surface  44  is connected at a first end  46  to a first end  48  of the rear mounting surface  42  and the bottom surface  44  is connected at a second end  50  to a first end  52  of the front mounting surface  40 . 
     The bottom surface  44  of the compartments comprises a generally rectangular opening  54 , the opening  54  allows for the passage of a push button actuator  56  (shown in FIG. 6) which extends from a bottom surface  58  of the auxiliary switch  30 . When the auxiliary switch  30  is installed in the circuit breaker  10 , the push button actuator  56  extends into the molded case  14  base  16  and is actuated by circuit breaker components located in the base. Additionally, the bottom surface  44  of the right auxiliary switch compartment  36  further comprises a right rejection slot  60 . The bottom surface  44  of the left auxiliary switch compartment  38  further comprises a left rejection slot  62 . The role of the right and left rejection slots  60 ,  62  will be later described in greater detail. 
     The rear mounting surface  42  comprises a top horizontal edge  66  spaced a parallel distance from a bottom horizontal edge  68 . Both the top and bottom horizontal edges  66 ,  68  comprise a series of shaped protrusions and indentations existing across the edges  66 ,  68 . In the preferred embodiment the series of shaped protrusions and indentations formed on the top horizontal edge  66  is a series of top rear mounting teeth  70 . A series of bottom rear mounting teeth  71  are formed on the bottom horizontal edge  68 . The top rear mounting teeth  70  formed on the top horizontal edge  66  and the bottom rear mounting teeth  71  formed on the bottom horizontal edge  68  extend towards each other. The front mounting surface  40  comprises a top horizontal edge  74 . As best shown in FIG. 7, the top horizontal edge  74  comprises a series of top front mounting teeth  78  that extend downward. 
     Among the possible switches  30  that can be installed in the right and left auxiliary switch compartments  36 ,  38 , are the unique right auxiliary switch  32  and the unique left auxiliary switch  34 , the switches being a normally open or a normally closed switch. For example, a plurality of unique right auxiliary switches  32  can be installed in the right auxiliary switch compartment  36 , with some of the switches  32  being normally open, normally closed, or any combination of the two. These different types of unique right auxiliary switches  32  can be placed anywhere in the right auxiliary switch compartment  36 . 
     The auxiliary switches  30  are uniformly packaged, referring to FIGS. 6,  7  and  9  a unique right auxiliary switch is shown, the only distinction between the outward appearance of the various auxiliary switches  30  is the addition of a rejection pin  83  formed on the bottom surface  58  of the auxiliary switch  30 . The rejection pin  83  is oriented differently for each of the unique switches. For simplicity, when describing the auxiliary switches  30 , emphasis is on the unique right auxiliary switch  32 . It being understood that any of the auxiliary switches, including a unique left auxiliary switch  34 , would be packaged in a similar manner, the only external difference being the location of the rejection pin  83 . 
     The right auxiliary switch  32  further comprises a front surface  84  and a rear surface  86 . The front surface  84  having a tab  85  disposed thereon, the tab  85  having a series of top front auxiliary teeth  88  extending upward from the tab. Teeth  88  are arranged to mesh with the top front mounting teeth  78  when installed. The rear surface  86  of the auxiliary switch  32  comprises a series of bottom rear auxiliary teeth  90  that mesh with the bottom rear mounting teeth  71  when installed. Extending upward from the rear surface  86  above a bottom rear auxiliary teeth  90  is a mounting prong  92 . A first end  94  of the mounting prong  92  is attached to the right auxiliary switch  32  at a point just above the bottom rear auxiliary teeth  90 . The mounting prong  92  is thin and flexible in comparison with the auxiliary switch  32 . The mounting prong  92  extends upward from the first end  94 , it angles slightly away from the rear surface  86  of the auxiliary switch  32 . A second end  96  of the mounting prong  92  is separated a distance from the rear surface  86  of the auxiliary switch  32 . A series of top rear auxiliary teeth  98  which are pointed upward are positioned near the second end  96  of the mounting prong  92 . 
     When installing the auxiliary switch  32  into the right auxiliary switch compartment  36 , the top front auxiliary teeth  88  are installed first so that they mesh with the top front mounting teeth  78  and tab  85  extends beneath the top horizontal edge  74 . Once the front teeth  88 ,  78  mesh, the auxiliary switch is retracted backwards so that the bottom rear auxiliary teeth  90  mesh with the bottom rear mounting teeth  71 . Finally the mounting prong  92  is flexed so that the top rear auxiliary teeth  98  can snap into place and mesh with the top rear mounting teeth  70 . Flexibility in mounting is enhanced because, the teeth  70 ,  71 ,  78  extend along the length of the right auxiliary switch compartment  36  and the rectangular opening  54  extends for a considerable length through the bottom surface. Therefore, a single right auxiliary switch  32  can be positioned anywhere in the compartment. 
     Referring to FIGS. 2 and 5, the mid-cover  18  can further comprise a bell alarm mechanism switch compartment  80  for housing the unique bell alarm mechanism switch  33  and a bell alarm trip switch compartment  82  for housing the unique bell alarm trip switch  35 . The bell alarm mechanism switch compartment  80  comprises a bell alarm mechanism rejection slot  100  and the bell alarm trip switch compartment  82  comprises a bell alarm trip rejection slot  102 . The bell alarm compartments  80 ,  82  could be located in the mid-cover  18  as shown in FIG.  2 . The unique designation indicates the lack of interchangeability. To ensure that the unique left auxiliary switch  34 , the unique right auxiliary switch  32 , the unique bell alarm mechanism switch  33  and the unique bell alarm trip switch  35  are not accidentally installed in the wrong compartment, the rejection slots prevent the installation of an auxiliary switch in an incompatible compartment. 
     As shown in FIG. 2, each of the compartments  36 ,  38 ,  80 ,  82  comprises a uniquely positioned rejection slot  60 ,  62 ,  100 ,  102 . Likewise, as shown in FIG. 6, each of the unique auxiliary switches  32 ,  34 ,  33 ,  35  comprises a uniquely positioned rejection pin  104 ,  106 ,  108 ,  110 . Referring to FIG. 8, an auxiliary switch  30  is shown comprising a right auxiliary switch rejection pin  104 , a left auxiliary switch rejection pin  106 , a bell alarm mechanism switch rejection pin  108  and a bell alarm trip switch rejection pin  110 . In a preferred embodiment, each of the unique switches  32 ,  34 ,  33 ,  35  would comprise only their accompanying rejection pin  104 ,  106 ,  108  or  110 . An alternative embodiment could comprise each unique switch comprising all four rejection pins  104 ,  106 ,  108 ,  110  wherein the installer would discard the three unrelated pins leaving the compatible rejection pin for the individual switch. 
     Each of the unique switches  32 ,  34 ,  33 ,  35  comprises an accompanying rejection pin  104 ,  106 ,  108 ,  110  and each of the compartments  36 ,  38 ,  80 ,  82  comprises a rejection slot  60 ,  62 ,  100 ,  102  positioned to accept only the auxiliary switch designed to work in the particular compartment. Therefore, the possibility of improper installation is eliminated. 
     Referring to FIGS. 10-15, according to a further embodiment, the mid-cover  18  of the molded case  14  comprises a right auxiliary compartment  112  and a left auxiliary compartment  114 . The right auxiliary compartment  112  is used to house at least one unique right auxiliary switch  116  and the left auxiliary compartment  114  is used to house at least one unique left auxiliary switch  118 . The auxiliary compartments  112 ,  114  are formed generally as a recess in the mid-cover  18  of a molded case  14  used in a molded case circuit breaker  10  (FIG.  1 ). 
     The compartments  112 ,  114  each comprise a first rear mounting channel  120 , a second rear mounting channel  122 , a base  124  and a front mounting surface  128 . The channels  120 ,  122 , base  124  and front mounting surface  128  are ideally formed as an integral part of the mid-cover  18 . The base further comprises an actuator access opening  126  used to allow passage of a push bottom actuator  130  extending from a bottom surface  132  of the right and left auxiliary switch  116 ,  118 . 
     The right auxiliary compartment  112  is shown in FIG.  11 . Although not shown in FIG. 11, the left auxiliary compartment  114  is identical. For ease of illustration, the right auxiliary compartment  112  will be described and unless otherwise noted, the right and left auxiliary compartment  112 ,  114  will use substantially similar elements. 
     Referring to FIG. 11, the right auxiliary compartment  112  comprises the first rear mounting channel  120  and the second rear mounting channel  122 . The channels  120 ,  122  are perpendicular to the base  124  and are located at a first end  134  of the base. The channels extend upward from the base  124 . Each channel  120 ,  122  has a U-shaped opening  136  extending through the length of the channel  120 ,  122 . The U-shaped openings  136  on the first channel  120  and the second channel  122  point towards one another as shown in FIG.  11 . 
     The front mounting surface  128  further comprises a top horizontal edge  138 , the edge  138  being similar to the top horizontal edge  74  used in the preferred embodiment, the only difference being the edge  138  does not comprise the teeth  78 . 
     Referring to FIGS. 14 and 15, the unique right auxiliary switch  116  and the unique left auxiliary switch  118  further comprise a front surface  140 , a rear surface  142  and the bottom surface  132 . The rear surface  142  of the switches  116 ,  118  further comprises a projection  144  that extends away from the switch  116 ,  118 . The projection  144  can be oriented near a bottom end  146  of the rear surface  142  or near a top end  148  of the rear surface  142 . It is the orientation of the projection  144  that prevents erroneous installation of the unique auxiliary switches  116 ,  118  into the wrong auxiliary compartment  112  or  114 . 
     It will be seen that all of the right auxiliary switches  116  preferably have the projections  144  located in the same position. Likewise, the unique left auxiliary switch  118  preferably have the projections  144  located in the same position, with the position of the projection  144  on the left auxiliary switch  118  different from the position of the right auxiliary switch  116 . For ease of illustration the right auxiliary switch  116  will have the projection  144  located near the bottom end  146  of the rear surface  142  and the left auxiliary switch  118  will have the projection  144  located near the top end  148  of the rear surface  142 . 
     Referring to FIGS. 12-15, the projection  144  is designed to slidingly engage a bottom mounting rail  150  or a top mounting rail  152 . The right auxiliary switch  116  comprising projections  144  oriented near the bottom end  146  will engage the bottom mounting rail  150  (FIG.  12 ). The left auxiliary switch  118  comprising projections  144  oriented near the top end  148  will engage the top mounting rail  152  (FIG.  13 ). Both the bottom and top mounting rails  150 ,  152  comprise a T-shaped opening  154  extending through the thickness “t” of the rails  150 ,  152 . The T-shaped opening  154  comprises a first opening  156  having a height of H 1  and a length of L 1 . The T-shaped opening  154  further comprises a second opening  158  having a height of H 2  and a length of L 2 . Where H 1  is greater than H 2  and L 2  is considerably greater than L 1 . The first opening  156  being contiguous with the second opening  158 . 
     The projection  144  further comprises a top lip  160  and a bottom lip  162  separated by a notch  164 . The notch  164  enables compression of the top lip  160  and the bottom lip  162  towards one another. The engagement of the auxiliary switch  116 ,  118  on its accompanying mounting rail  150 ,  152 , is facilitated by, squeezing the top lip  160  and the bottom lip  162  together so that the top and bottom lip  160 ,  162  can pass through the first opening  156  on the mounting rail  150 ,  152 . Once the top and bottom lip  160 ,  162  pass through the first opening  156 , the auxiliary switch  116 ,  118  is secured to the mounting rail  150 ,  152 . To position the auxiliary switch  116 ,  118 , the top and bottom lip  160 ,  162  are squeezed towards one another and slid along the mounting rail  150 ,  152 . The long second opening  158  enables one to mount multiple compatible auxiliary switches  116 ,  118  on a single rail  150 ,  152 . 
     Referring to FIGS. 11,  12  and  14 , once the required auxiliary switches  116 ,  118  are mounted on the compatible rail  150 ,  152 , the rail can slide into the compartment  112 ,  114 . The bottom mounting rail  150  slides into the U-shaped openings  136  on the first and second rear mounting channels  120 ,  122 . A top edge  168  on the front surface  140  of the right auxiliary switch  116  is engaged under the edge  138  of the front surface  128  as the bottom mounting rail  150 , assembled with at least one right auxiliary switch  116 , is slid into place. To ensure that the mounting rail  150  is snuggly fit into the first and second mounting channels  120 ,  122 , a flexible extension  166  is included on a first end of the mounting rail  150 . As the mounting rail  150  slides in the channels  120 ,  122  the flexible extension  166  is compressed to snugly hold the mounting rail  150  in place. 
     The auxiliary switch mounting configuration described herein allows customization of a molded case circuit breaker by installing auxiliary switches. By utilizing one left side compartment and one right side compartment an installer can effortlessly install various combinations of auxiliary switches into each compartment. There is a unique left side auxiliary switch which is intended for installation only in the left side compartment and a unique right side auxiliary switch which is intended for installation only in the right side compartment. The unique left side auxiliary switch and the unique right side auxiliary switch are designed to prevent against erroneous installation. 
     It will be understood that a person skilled in the art may make modifications to the embodiments shown herein within the scope and intent of the claims. While the present invention has been described as carried out in specific embodiments thereof, it is not intended to be limited thereby but is intended to cover the invention broadly within the scope and spirit of the claims.