Abstract:
A compact operating mechanism for switches and circuit interrupters provides improved input drive arrangement and more particularly to a quick-make quick-break operating mechanism for electrical circuit interrupters, i.e. load-interrupter switches and fault interrupters, the drive input arrangement being capable of either power or manual operation without the necessity of any coupling/decoupling or mode selection.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/239,311 filed on Oct. 10, 2000 in the names of T. O. Fanta et al. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a compact operating mechanism for switches and circuit interrupters with improved input drive arrangement and more particularly to a quick-make quick-break operating mechanism for electrical circuit interrupters, i.e. load-interrupter switches and fault interrupters, the drive input arrangement being capable of either power or manual operation without the necessity of any coupling/decoupling or mode selection. 
     2. Description of Related Art 
     Various operating mechanisms for electrical switches and circuit interrupters provide multiple operational states at an output corresponding to the desired operational states of the switch controlled by the mechanism. For example, U.S. Pat. Nos. 5,895,987 and 6,025,657 are directed to a power operator capable of manual or power operation without decoupling. Additionally, U.S. Pat. No. 4,146,764 is directed to a spring-operated closing mechanism for a circuit breaker that does not require coupling/decoupling, the arrangement including side-by-side ratchet control plates with multiple rods passing therethrough that function as pawls. A separate opening spring is utilized for the opening function. Considering other operating mechanisms, U.S. Pat. No. 3,563,102 discloses a quick-make quick-break mechanism for operating a switch between open and closed positions. Other operating mechanisms are shown in the following U.S. Pat. Nos. 3,845,433; 4,293,834; 5,140,117; and 5,224,590. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a principal object of the present invention to provide a compact operating mechanism for switches and circuit interrupters with improved input drive arrangement and more particularly to a quick-make quick-break operating mechanism for electrical circuit interrupters, i.e. load-interrupter switches and fault interrupters, the drive input arrangement being capable of either power or manual operation without the necessity of any coupling/decoupling or mode selection. 
     It is another object of the present invention to provide a compact operating mechanism that incorporates manual and power drive inputs without the necessity of coupling/decoupling functions. 
     These and other objects of the present invention are achieved by a compact operating mechanism for switches and circuit interrupters with improved input drive arrangement and more particularly to a quick-make quick-break operating mechanism for electrical circuit interrupters, i.e. load-interrupter switches and fault interrupters, the drive input arrangement being capable of either power or manual operation without the necessity of any coupling/decoupling or mode selection. 
    
    
     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: 
     FIG. 1 is a front elevational view of a switch incorporating the operating mechanism in accordance with the principles of the present invention; 
     FIGS. 2 and 3 are front elevational views of the operating mechanism of FIG. 1 with parts cut away and removed for clarity; 
     FIG. 4 is an enlarged elevational view of the operating mechanism of FIGS. 2 and 3 and illustrating a different operative position; 
     FIG. 5 is an elevational view of the ratchet wheel of the operating mechanism of FIGS. 2-4; and 
     FIGS. 6 and 7 are partial views on an enlarged scale of portions of the operating mechanism of FIGS. 2-4 and illustrating operating control features thereof. 
    
    
     DETAILED DESCRIPTION 
     Referring now to FIG. 1, an operating mechanism  10  of the present invention is of the quick-make, quick-break variety and is useful to provide operation of a circuit interrupter, e.g. in a specific application, a group-operated switch  12  as shown in FIG.  1  and in U.S. Pat. Nos. 4,398,072, 5,075,521, 5,091,616 and 5,103,111. In response to power supply connections and control signals, the operating mechanism  10  charges a stored energy mechanism and controls operation thereof between an open position and a closed position. Additionally, the operating mechanism  10  in response to a manual input at  20 , operates between open and closed positions. The operating mechanism  10  includes a housing  16  having a removable cover portion  18 . Referring now additionally to FIGS. 2-5, the operating mechanism  10  includes a stored-energy mechanism  24 , that is rotated via a drive input  26 . The operating mechanism  10  via a drive output lever  29  at an output at  27  operates the drive linkage of the switch, e.g. at  31  in FIG.  1  and at  93 ,  95  of FIG. 5 in U.S. Pat. No. 5,091,616. The stored energy mechanism  24  is of the general type shown in U.S. Pat. Nos. 3,563,102 and 5,075,521. The drive input  26  is driven through a linkage  28  which in turn is connected to be driven at  30  from a drive arrangement  32 . The drive arrangement at  32  includes a ratchet wheel  34  that fixedly carries a drive lever  36 , a distal end  38  of the drive lever  36  including a pin  40  to provide connection to the linkage  28  at  30 . The ratchet wheel  34  is rotatably carried about an output shaft  50  of a motor drive  52 . As seen in FIG. 5, the ratchet wheel  34  is driven by a pair of pawls  42 ,  44  mounted within a hub  46  carried within the ratchet wheel  34  having internal ratchet teeth  48 , the hub  46  being keyed to the output shaft  50  and being spring-biased at  54  in an outward direction. For manual operation, a manual drive lever  60  is provided that includes a manual drive pawl  62  pivotally carried by the manual drive lever  60 , the manual drive pawl  62  also being characterized as an indexing pawl since multiple strokes of the manual drive lever  60  are required as will be explained in detail hereinafter. The manual drive lever  60  is pivotally mounted at  50  and includes a bumper at  64 . The ratchet wheel  34  includes external ratchet teeth  37  arranged about the outer periphery  35  of the ratchet wheel  34 . The drive pawls  42 ,  44  are overdriven during the manual driving of the ratchet wheel  34  via the indexing pawl  62  thereby not backdriving the motor drive  52 . Correspondingly, during power operation, the manual drive pawl  62  is overdriven as the ratchet wheel  34  is rotated by the pawls  42 ,  44 . A holding pawl  70  is provided to prevent backdriving of the stored energy mechanism  24  and the ratchet wheel  34 . 
     In normal operation where a power supply is present, the operating mechanism  10  charges the stored energy mechanism  24  to a predetermined pre-charged point prior to an opening or closing operation such that the operating mechanism  10  is always ready for a fast open or close operation upon command. When it is desired to change the state of the operating mechanism  10 , e.g. from open to closed or closed to open, the operating mechanism  10  is controlled via the output shaft  50  of the motor drive  52  to drive the stored-energy mechanism  24  beyond the pre-charged state and past the release point of the stored-energy mechanism  24  thereby causing operation. The motor drive  52  immediately recharges the stored-energy mechanism  24  to the pre-charged state for the next operation. 
     When a power supply is not present, manual operation is available via the manual input at  20  to operate the operating mechanism  10  to change the state of the driven switch. Specifically, a manually operable arrangement  100  including a pull ring  102  that is reciprocated between the positions of FIGS. 2 and 3 a number of times to charge and operate the stored-energy mechanism  24 . The manually operable arrangement  100  includes a pull rod  104  biased by a spring  106  with the spring being retained between the cover  18  and the pull rod  104  and being compressed upon each downward stroke of the pull ring  102 . Thus, the pull rod is returned under the bias of the spring  106 . The pull rod  104  is connected at  108  to pivot the manual drive lever  60 . 
     For normal operation where a power supply is present and considering now the arrangement of the operating mechanism  10  to charge the stored energy mechanism  24  to the predetermined pre-charged point and referring specifically now to FIGS. 4,  6  and  7 , two control grooves  120 ,  122  arranged on the periphery of an outside hub  39  of the ratchet wheel  34  cooperate with a limit switch assembly  124 . The limit switch  124  is arranged to control power to the motor drive  52 . The limit switch assembly  124  includes an intermediate lever  126  that is biased toward the ratchet wheel  34  via a spring  128  and that is positioned to ride on the outside hub  39  of the ratchet wheel  34 . When the motor drive  52  has charged the stored energy mechanism  24  to the pre-charged state, the intermediate lever  126  moves into one of the control grooves  120 ,  122  actuating the limit switch  124  which turns off the motor drive  52  as illustrated in FIG.  7 . Thus, the operating mechanism  10  is maintained in the pre-charged position for either opening or closing upon command. The positions illustrated in FIG. 6 depicts the position of the intermediate lever  126  just prior to actuation of the limit switch  124  before reaching the pre-charged position. The expanse and shape of the control grooves  120 , 122  permit back driving and coasting of the motor drive  52  without deactuating the limit switch  124 . 
     Considering now an interlock feature of the operating mechanism  10  to prevent manual operation when a disconnect switch of the group-operated switch  12  is in an open position, a movable cam surface  130  is provided to lift the manual indexing pawl  62  via contact thereof away from engagement with the ratchet wheel  34  as shown in FIG.  4 . Thus, operation of the manual drive lever  60  will neither charge nor trip the operating mechanism  10 . Movement of the disconnect operating linkage  17  (FIG. 1) is communicated to the operating mechanism  10  via a connecting member  19 . 
     While there have been illustrated and described various embodiments 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.