Abstract:
A retention arrangement for a circuit interrupter to ensure that ensures the retention of the circuit interrupter in its mounting. The retention arrangement cooperates with a latch member of the mounting for the circuit interrupter. Accordingly, the circuit interrupter is retained in its mounting even where the dimensions of the circuit interrupter may vary from the nominal specified dimensions.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/755,943 filed Jan. 3, 2006. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to the field of circuit interrupters for electrical power transmission and distribution and more particularly to a retention arrangement for a circuit interrupter that ensures the retention of the circuit interrupter in its mounting. 
   2. Description of the Related Art 
   Many types of circuit interrupting devices in the electrical power distribution and transmission field are installed in mountings so as to be selectively removable from the mountings. For example, various types of mountings for diverse circuit interrupters are shown in U.S. Pat. Nos. 6,867,679 and 4,123,639. 
   While the mountings of the prior art may be generally suitable for their intended uses, it would be desirable to provide a retention arrangement for circuit interrupters that is easy to operate and that ensures retention of the circuit interrupter in its mounting especially where the dimensions of the circuit interrupter may vary from the nominal specified dimensions. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the specification taken in conjunction with the accompanying drawing in which: 
       FIGS. 1 and 2  are front elevational and top plan views respectively of a prior art mounting for a circuit interrupter; 
       FIGS. 3 and 4  are front elevational and top plan views respectively of an upper portion of a mounting having a retention arrangement according to the present invention and illustrating a position when the circuit interrupter is not installed therein; 
       FIGS. 5 and 6  are front elevational and top plan views respectively of an upper portion of a mounting having the retention arrangement according to the present invention and illustrating a position when the circuit interrupter is installed and retained therein; and 
       FIG. 7  is front elevational view of the mounting of  FIGS. 3-6  illustrating an operative position when a circuit interrupter is being removed from the mounting. 
   

   DETAILED DESCRIPTION 
   Referring now to  FIGS. 1 and 2 , a mounting  10  of the type shown in U.S. Pat. No. 6,867,679 is illustrated supporting a circuit interrupter  12 , e.g. for use in metal-enclosed gear or the like in the electrical power transmission and distribution field. In the specific illustrative mounting, the mounting  10  also supports a second circuit-interrupter  14  so as to function as a double interrupter mounting. The circuit interrupters  12 ,  14  are fuses or the like, for example, of the general type shown in U.S. Pat. No. 4,123,639 and available under the tradename NX fuses from Cooper Industries. Of course, it should be understood that the mounting  10  and the retention arrangement of the present invention are suitable for use with other types of circuit-interrupting devices. The mounting  10  includes upper and lower terminal and support arrangements  16 ,  18  respectively that cooperate with upper and lower device mounting studs  20 ,  22  respectively of the circuit interrupters  12 ,  14 . The device mounting studs  20 ,  22  also function as electrical circuit connection points to connect the circuit interrupters  12 ,  14  in an electrical circuit via respective upper and lower contact assemblies  24 ,  26  of the mounting  10 . The upper and lower contact assemblies include resilient retention facilities for providing suitable electrical contact forces when engaged with the device mounting studs  20 ,  22 . 
   Thus, the upper and lower terminal and support arrangements  16 ,  18  retain the circuit interrupters  12 ,  14  within the mounting  10  and in suitable electrical circuit connection. The upper and lower terminal and support arrangements  16 ,  18  also preferably include respective guiding arrangements  17 ,  19  that are bifurcated to receive and guide the device mounting studs  20 ,  22  during insertion of the circuit interrupters  12 ,  14 . 
   Each of the upper and lower terminal and support arrangements are selectively operable to release the circuit interrupters  12 ,  14  for removal from the mounting  10 , e.g. upper and lower terminal and support arrangements  16   a ,  18   a  are operable to release the circuit interrupter  12  and upper and lower terminal and support arrangements  16   b ,  18   b  are operable to release the circuit interrupter  14 . Accordingly, the circuit interrupters  12 ,  14  are each individually removable from the mounting  10 . In another specific arrangement, the upper terminal and support arrangement  16  is operable to release the circuit interrupters  12 ,  14  with the lower terminal and support arrangement  18  being of the general type as shown in U.S. Pat. No. 4,123,639. 
   In a specific application, the circuit interrupters  12 ,  14  are current-limiting fuses that are rather massive (e.g. 30 pounds or more) and are intended for deenergized circuit manipulation by an operator for removal and replacement. For example, the upper and lower terminal and support arrangements  16 ,  18  are operable via a hookstick to release the circuit interrupter  12  or  14  and a stick with a clamp attachment is utilized to grasp and remove the circuit interrupter  12  or  14  from the mounting  10 . Reference may be made to S&amp;C Electric Company Descriptive Bulletin 851-30 for more information on such handling tools. 
   With additional reference now to  FIGS. 3-6 , each of the upper and lower terminal and support arrangements  16   a ,  16   b ,  18   a  and  18   b  include a latch arm  30  that is moved to release the respective device mounting stud  20 ,  22  from a retained holding position to a latch released position. In a specific embodiment, the latch arms  30  include holes  32  formed therethrough for passage of the device mounting studs  20 ,  22  and engagement and retention thereof by the latch arms  30 . Thus, the latch arms  30  retain the circuit interrupters  12 ,  14  in the mounting  10  until operated by manipulation away from the device mounting studs  20 ,  22  so as to release the device mounting studs  20 ,  22  from engagement within the holes  32 . 
   In accordance with important aspects of the present invention, a retention arrangement  60  is provided to ensure the retention of the circuit interrupters  12 ,  14  in the mounting  10 . Specifically, the retention arrangement  60  includes an actuating arm  62  that holds the latch arm  30  in an open position in  FIGS. 3 and 4  with the circuit interrupters  12 ,  14  removed from the mounting  10 . With additional reference now to  FIGS. 5 and 6 , when the circuit interrupters  12 ,  14  are installed into the mounting  10 , the device mounting studs  20 ,  22  engage and move the actuating arm  62  via guiding surfaces  69  formed in the arms  62 . As the arm  62  moves, an extending tab  64  of the arm  62  enters a hole  34  in the latch arm  30  permitting the latch  30  to move toward a closed, latched position. In this position, the circuit interrupters  12 ,  14  are retained securely due to the interference of the latch  30  and the arm  62 . The arm  62  includes an extending portion  66  that carries the tab  64  and a mounting portion  68  that extends at an approximate right angle to the portion  66 . The mounting portion  68  is pivotally mounted with respect to the mounting  10  at pivot point  70 . In a specific implementation, stop pins  71  are provided to define the open, released position of the arms  62 . Also, in a specific implementation, the mounting  10  includes guiding brackets  73  to assist in the insertion of the mounting studs  20 ,  22  and relative positioning with respect to the arms  62 . 
   With reference now to  FIG. 7 , to remove the circuit interrupters, the latch  30  is moved outward with a handling tool. A resilient guiding member  50  which may also be characterized as a kick-out spring and as shown in U.S. Pat. No. 6,867,679, the device mounting studs  20 ,  22  are moved out of the position in  FIGS. 5 and 6 . The movement of the studs  20 ,  22  also causes movement of the arm  62  to the open, released position. 
   While there has been illustrated and described a preferred embodiment of the present invention, it will be apparent that various changes and modifications will occur to those skilled in the art. Accordingly, it is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the present invention.