Abstract:
A circuit breaker assembly includes a plurality of circuit breakers each including a housing with a trip mechanism therein and each having an opening in a side of the respective housing. Each trip mechanism has a coupler disc connected thereto. The plurality of circuit breakers are aligned in an end-to-end fashion with a trip member positioned along a side of the housings and connected to the coupler discs such that if the first trip mechanism actuates from a untripped state to a tripped state the trip member actuates the second trip mechanism from a untripped state to a tripped state and vice versa.

Description:
FIELD OF THE INVENTION 
     The invention relates to a multi-pole circuit breaker arrangement in general, and in particular to a multi-pole circuit breaker arrangement that provides two or more circuit breakers arranged in tandem wherein the circuit breakers tripping mechanisms are connected via a trip member such that the tripping of one circuit breaker will cause the interconnected breakers to trip simultaneously. 
     BACKGROUND OF THE INVENTION 
     This invention relates to circuit breakers used to protect an electrical circuit from damage caused by ground fault or a short circuit. If a power surge occurs in a circuit protected by the circuit breaker, for example, the breaker will trip. This will cause a breaker that was in the “on” position to flip to the “off” position, and will interrupt the electrical power leading from that breaker. By tripping in this way, a circuit breaker can prevent damage from occurring on an overloaded circuit, and can also prevent the destruction of the device that is drawing the electricity or other devices connected to the protected circuit. 
     A typical circuit breaker includes a line and a load. Generally, the line is connected to an incoming electrical power source, e.g., power supplied from a power network such as a utility line. This is sometimes referred to as the input into the circuit breaker. The load, sometimes referred to as the output, connects the circuit breaker to the electrical circuit and components connected to the circuit being fed from the circuit breaker. A circuit breaker may protect an individual component connected directly to the circuit breaker, for example, an air conditioner, or a circuit breaker may protect multiple components, for example, household appliances connected to a circuit which terminates at electrical outlets. 
     It is known to provide to provide circuit breakers of a fixed type in the panel board. For example, single pole, two-pole and three-pole circuit breakers are all known, which can variously be connected to single phase, two-phase and three-phase circuit for feeding particular circuits. However, a three-phase circuit breaker can only ever be configured as a three-phase circuit breaker and cannot be used to feed a single phase load. 
     In some applications, it is desirable to have two or more circuit breakers interconnected such that they trip simultaneously. For example, U.S. Pat. No. 4,504,807, which is hereby incorporated by reference, discloses a multi-pole circuit breaker arrangement where a common trip coupler connects the circuit breakers through abutting side walls of the switch cases. In this arrangement, opposing portions cooperate with portions of a U-shaped common trip members inside the adjacent switch cases in order to cause pivotal movement of one of these members to achieve coaxial movement of the coupler and hence of the adjacent trip member in the adjacent case. The multi-pole circuit breaker also has a single handle attached to an elongated internal connector for actuating the breakers in unison with one another. 
     However, the circuit breaker arrangement disclosed in U.S. Pat. No. 4,504,807 has many disadvantages. For instance, the arrangement of the breakers is bulky and requires a large space to fit in a circuit breaker panel. This is a problem in situations where space is limited and a multi-pole breaker with a slim foot print is needed. Such scenarios regularly happen in modern space efficient circuit breaker panels and in other areas, such as server rooms where it is necessary to have a multi-pole circuit breaker in a slim area between servers. 
     Another problem with prior art designs, is that in order to assemble the three pole design disclosed, at least three different types of circuit breakers must be manufactured. This is necessitated by the need to interconnect the breakers through a cavity in the abutting side walls of the switch cases. Thus, for the design shown, the middle breaker must have a cavity on both abutting sidewalls, while two side breakers require a cavity on opposing side walls. Still another problem with the prior art design is that not only must differing switch cases be made for the side wall cavities, but also for the single handle arrangement. Thus, while the center breaker has a top opening for the single handle, the switch cases for the side breakers have a flat top. As a result, at least six different cases must be manufactured in order to assemble the breaker disclosed. 
     SUMMARY OF THE INVENTION 
     It is desired, therefore, to provide a slim-profile multi-pole circuit breaker arrangement where a common trip coupler may be used to connect a at least two separate circuit breakers. 
     It is further desired to provide a multi-pole circuit breaker design that requires less unique parts, which is relatively inexpensive to manufacture and inventory. 
     Accordingly, one object is to provide a circuit breaker assembly including a first circuit breaker having a first housing containing a first trip mechanism with a first axis of operation, the first housing having a first circular opening; a second circuit breaker having a second housing containing a second trip mechanism with a second axis of operation, the second housing having a second circular opening; a first coupler disc in the first opening and connected to the first trip mechanism; a second coupler disc in the second opening and connected to the second trip mechanism; the first circuit breaker and the second circuit breaker aligned such that the first axis of operation and the second axis of operation are substantially parallel and separated by a first distance; an elongated trip member having a first end with a first pivot connection and a second end with a second pivot connection; the first pivot connection connected to the first coupler disc and the second pivot connection connected to the second coupler disc such that when the first trip mechanism actuates from a untripped state to a tripped state, the elongated trip member actuates the second trip mechanism from a untripped state to a tripped state; and a cover extending over the trip member, the cover fastened to the housing of first circuit breaker and the housing of the second circuit breaker. 
     It is another to provide a circuit breaker assembly wherein each of the circuit breakers has a handle for manually actuating the trip mechanisms between the untripped state and the tripped state and where the handles are coupled via a connector. In one example, the connector may be a bar that is attached to the handles via a fastener. 
     In other examples the connector is a one-piece assembly having a center section from which a first and a second set of legs protrude from opposite sides, the first set of legs having a set of first projections protruding inward and the second set of legs having a set of second projections protruding inward, where the first set of projections connect to one handle and the second set of projections connect to the other handle. 
     In still other examples, the connector is an elongated slider having a first end with a first cavity and a second end with a second cavity, where one handle fits into the first cavity and the other handle fits into the second cavity. 
     It is yet a further object to provide a circuit breaker assembly where a first gap between the first opening and the first coupler disc and a second gap between the second opening and the second coupler disc are provided such that an inner edge of the first opening acts as a bearing surface for an outside edge of the first coupler, and an inner edge of the second opening acts as a bearing surface for an outside edge of the second coupler. 
     These and other objects are achieved by providing a circuit breaker assembly including a first circuit breaker having a first housing containing a first trip mechanism, the first housing having a side, a first end of the first housing and a second end of the first housing, the first and second ends of the first housing being perpendicular to the side of the first housing and being parallel to one another; a second circuit breaker having a second housing containing a second trip mechanism, the second housing having a side, a first end of the second housing and a second end of the second housing both being perpendicular to the side of the second housing and being parallel to one another; the first circuit breaker and the second circuit breaker aligned such that the second end of the first housing and the first end of the second housing contact one another; and an elongated trip member that runs along the side of the first housing and the side of the second housing, the elongated trip member connected to the first trip mechanism through an opening in the side of the first housing and the second trip mechanism through an opening in the side of the second housing, such that when the first trip mechanism actuates from a untripped state to a tripped state, the elongated trip member actuates the second trip mechanism from a untripped state to a tripped state. 
     It is another object to provide a circuit breaker assembly wherein a first circuit breaker has a first handle for manually actuating the first trip mechanism between the untripped state and the tripped state, and a second circuit breaker has a second handle for manually actuating the second trip mechanism between the untripped state and the tripped state, such that the first handle and the second handle are mechanically coupled together via a connector. In one example, the connector is a bar that is attached to the first handle by a first fastener and the second handle by a second fastener. 
     In other embodiments the connector is a one-piece assembly having a center section from which a first and second set of legs protrude from opposite sides, the first set of legs having a set of first projections protruding inward and the second set of legs having a set of second projections protruding inward, wherein the first set of projections connect to a first handle and the second set of projections connect to a second handle. 
     In still other examples, the connecter is an elongated slider having a first end with a first cavity and a second end with a second cavity, where the first handle fits into the first cavity and the second handle fits into the second cavity. 
     It is yet a further object to provide a circuit breaker assembly including a first and second coupler, where the first coupler fits into a first opening and is connected to a first trip mechanism and a second coupler fits into a second opening and is connected to a second trip mechanism such that the elongated trip member is connected to the first and second coupler. 
     It is another object to provide a circuit breaker assembly such that a first opening and a second opening in the respective housings are circular, and first and second couplers are provided as discs. In certain examples a first gap between a first opening and a first coupler disc and a second gap between a second opening and a second coupler disc are provided such that an inner edge of the first opening acts as a bearing surface for an outside edge of the first coupler, and an inner edge of the second opening acts as a bearing surface for an outside edge of the second coupler. 
     Other objects are achieved by providing a circuit breaker assembly including a plurality of circuit breakers, each circuit breaker comprising a housing having a side and first and second ends that are perpendicular to the side, the two ends being parallel to one another. The circuit breaker assembly further includes a handle that is moveable between an on position and an off position, and a circuit breaker linkage mechanism having a tripped state and an untripped state. The circuit breaker linkage mechanism is disposed to change a position of at least one contact when the circuit breaker linkage mechanism changes state, and the circuit breaker linkage mechanism is operably connected between the handle and the at least one contact, such that movement of the handle causes movement of the circuit breaker linkage mechanism, thereby causing movement of the at least one contact. The circuit breaker linkage mechanism further includes an opening on a first side of the breaker, where the plurality of breakers are aligned end to end such that the sides of the housings are oriented in the same direction and are aligned on a plane. The circuit breaker linkage mechanism is provided such that an elongated trip member extends along the sides of the plurality of circuit breakers, the elongated trip member being mechanically connected to each of the circuit breaker linkage of the plurality of breakers such that when one of the circuit breaker linkages actuates from the untripped state to the tripped state, the remaining circuit breaker linkages of the plurality of circuit breakers are also actuated from the untripped state to the tripped state. Finally, the circuit breaker linkage mechanism includes a handle coupler connecting each handle of the plurality of breakers allowing a user to simultaneously actuate the plurality of circuit breakers. 
     Other objects of the invention and its particular features and advantages will become more apparent from consideration of the following drawings and accompanying detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustration of two circuit breakers showing an exploded view of the trip member connection. 
         FIG. 2  is an illustration of the two circuit breakers according to  FIG. 1 . 
         FIGS. 3 and 4  are illustrations of one of the circuit breakers according to  FIG. 1  in the closed and open positions respectively. 
         FIG. 5  is an illustration of the circuit breakers according to  FIG. 1  showing the trip member connection in the closed position. 
         FIG. 6  is an illustration of the circuit breakers according to  FIG. 1  showing the trip member connection in the open position. 
         FIG. 7  is an illustration of a cross-section of the circuit breakers according to  FIG. 5  showing the trip member connection. 
         FIG. 8  is an illustration of a handle connection member. 
         FIG. 9  is an illustration of circuit breakers incorporating the handle connection member of  FIG. 8 . 
         FIG. 10  is an illustration of another example of the handle connection member. 
         FIG. 11  is an illustration of circuit breakers incorporating the handle connection member of  FIG. 10 . 
         FIG. 12  is an illustration of another example incorporating a handle connection member. 
         FIG. 13  is an illustration of the circuit breaker arraignment according to  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-2  show a multi-pole circuit breaker  10  according to aspects of the invention.  FIG. 1  illustrates an exploded view of the multi-pole circuit breaker  10 . The multi-pole circuit breaker includes two circuit breakers  12 ,  14 , each having a manual switch handle  15  and an actuator  22  for the trip mechanisms connected via a common trip assembly  20 . The common trip assembly  20  is concealed by a cover  25  which also connects the two circuit breakers  12 ,  14  together. As can be seen in  FIG. 1  both circuit breakers  12 ,  14  have the same housing assembly made up of an outside case  16  and an inside case  18 . The inside case  18  has a circular opening  32  which provides access to the actuator  22  for the tripping mechanism. Each of the circuit breakers  12 ,  14  has a top  37  from which the manual switch handle  15  extends, two ends  36  that have the same width as the top  37  and a front face  35 . The circuit breakers  12 ,  14  are aligned end  36  to end  36  and the front face  35  of each of the circuit breakers  12 ,  14  form a larger surface. The actuators  22  are separated such that the actuator pivot points  23  are separated by a distance that in the preferred embodiment is greater than or equal to the length  38  of the front face  35 . 
     The common trip assembly  20  comprises a coupler disc  24  for each of the two circuit breakers  12 ,  14  and an elongated trip member  21  which connects the coupler discs  24 . For each coupler disc  24 , one side has two projections  26  which fit into corresponding openings  27  in the actuator  22  and on the other side has a single pivot projection  28 . The elongated trip member  21  has two spaced apart pivot openings  30 ,  31 , which fit onto a corresponding pivot projection  28  to form two spaced apart pivot points on the elongated trip member  21 . The space separating the pivot openings  30 ,  31  is approximately equal to the space separating the actuator pivot points  23 . When assembled, the coupler disc  24  fits into the circular opening  32  of the inside case  18  such that the elongated trip member sits along the exterior front face  35  of the inside case  18  of the circuit breakers  12 ,  14 . 
       FIGS. 3-4  are a side view of the internal components of each circuit breaker  12 ,  14 . The circuit breaker includes a stationary contact  105  connected to a line terminal  110 . The line terminal receives electricity from a power source. A movable contact  115  is disposed on a movable contact arm  120  which can be moved between a closed position shown in  FIG. 3  and an open position/tripped state shown in  FIG. 4 . 
     The movable contact  115  is connected to a load terminal  160  through a fault detector  150  and a connector  116 . When the movable contact  115  is in a closed position/untripped state, as shown in  FIG. 3 , the stationary contact  105  and the moveable contact  115  are in contact with each other, and electricity can flow from line terminal  110  to load terminal  160  through contacts  105  and  115 . 
     The movable contact arm  120  is also connected to a tripping mechanism  140  which includes a collapsible linkage  145 . The fault detector  150  is configured to activate the tripping mechanism  140  when a fault condition occurs, such as excess current, thereby causing the collapsible linkage  145  to collapse and separating the contacts  105 ,  115 . The collapsible linkage  145  can also be collapsed via the actuator  22  when the actuator  22  is rotated in a clockwise direction. 
     In some applications, the fault detector is a solenoid which is disposed inline with the circuit. If the current through the solenoid exceeds a certain level, the solenoid generates an electromagnetic field sufficient to activate the tripping mechanism. The solenoid may also optionally incorporate a plunger or other armature which activates the tripping mechanism when the current exceeds a certain level. 
     It is understood that other fault detection methods may also be employed, which trip the tripping mechanism upon the occurrence of a specific condition. 
     The handle  15  is connected to the movable contact arm  120  via the collapsible linkage  145 . The handle  15  is provided for opening and closing movable contact arm  120 . 
       FIGS. 5-6  are a side cut-away view of the assembled breakers  12 ,  14  and the common trip assembly  20  of  FIG. 1 .  FIG. 5  shows the assembled breakers  12 ,  14  in the untripped state and  FIG. 6  shows the assembled breaker  12 ,  14  in the tripped state. As signified by the arrow in  FIG. 5 , when one of the breakers  12 ,  14  trips, the elongated trip member  21  trips the other breaker by either pushing or pulling the interconnected coupler disc  24  of the untripped breaker. Thus, if the left circuit breaker  12  experiences a fault condition, such as excess current, the fault detector  150  will activate the tripping mechanism  140  causing the collapsible linkage  145  to collapse, separating the contacts  105 ,  115  and rotating the coupler disc  24  clockwise. The rotation of the coupler disc  24  in the left circuit breaker  12  is then transmitted to the coupler disc  24  of the right circuit breaker  14  through the elongated trip member  21  activating the tripping mechanism  140  causing the collapsible linkage  145  to collapse and separating the contacts  105 ,  115  of the right circuit breaker  14 . 
     As further shown in  FIGS. 5-6 , a gap is provided between the coupler disc  24  and the circular opening  32  on the inside case  18 . The width of the gap provided will vary by application. For instance, in heavy duty applications the force exerted on the trip member  21  by the coupler disc  24  can be rapid and have a high magnitude, which when transmitted through the elongated trip member  21  can cause the coupler discs  24  to shift and exert a large amount of force on the tripping mechanism through the actuator  22 . Such a force can cause malfunctions and premature wear to the components of the circuit breaker. Thus, in order to limit this force, the gap provided between the coupler disc  24  and the circular opening  32  on the inside case  18  is narrowed such that during actuation the outer edge  40  of the coupler disc  24  interacts with the inner edge  42  of the circular opening  32  in the inside case  18 . This interaction acts as a bearing surface and helps to restrict the motion in the system to the desired rotational motion on the actuator  22 . The coupler disc  24  inserted within the circular opening  32  on the inside case  18  is shown in  FIG. 7 , which is a cross-sectional view of the breaker of  FIG. 5 . 
     If certain types of circuit breakers are used in the present invention, it is not possible to simultaneously reset the tripping mechanisms of the circuit breakers through the common trip assembly  20 . Therefore, it may be necessary to connect the handles  15  of the circuit breakers in order to reset the circuit breaker assembly  10  after either a fault or if the breakers have been manually tripped.  FIGS. 8-13  show three different embodiments of connectors for the handles  15  of the circuit breakers  12 ,  14 . The embodiment of  FIGS. 8-9  shows a connecting bar  50 , which connects the holes  17  in the handles  15  via a fastener  52 . The embodiment of  FIGS. 10-11  shows a single piece connector  60 . The single piece connector  60  has middle handle portion  68  from which two legs  62 ,  64  extend from either side. All four of the legs  62 ,  64  have a projection  66  extending inward. The four projections  66  connect with the holes  17  in the handles  15 . 
       FIGS. 12-13  show a third embodiment of a handle connector  80 , wherein the cover  70  is formed in a L-shape such that it conceals both the common trip assembly  20  and the handles  15  for the circuit breaker  12 ,  14 . The cover  70  has an open space  76  in which the handles  15  for the circuit breaker  12 ,  14  are contained and a top opening  72  to access the handle connector  80 . The open space  76  houses the handle connector  80  and provides a track for the handle connector  80  to slide back and forth. The handle connector  80  has two extension pieces  82  with a cavity  84  at their distal end. The handle  15  for each breaker  12 ,  14  fits into the cavity  84  at the end of the extension piece  82 . When manually tripping or resetting the circuit breakers  12 ,  14  a user simply moves the handle connector  80  to the desired position and the handles  15  of the breakers are actuated by the cavity  84  at the end of each extension piece  82 . The advantages of the embodiment shown in  FIGS. 12-13  are that the L-shaped case provides more rigidity to the assembly and also prevents dust and other debris from entering the inside of the breakers  12 ,  14  through the area of the where the handles  15  extend. 
     Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many modifications and variations will be ascertainable to those of skill in the art.