Abstract:
A device is for controlling the closing of a power circuit breaker according to operational parameters. The device includes an indication element for indicating the readiness for closing and a coupling element which interacts with the indication element. The operational parameters, for example, energy store empty or switchgear cell door open cause the indication element to pivot into the position not ready for closing and cause the coupling element to move into its disabled position. The indication element for indicating the readiness for closing and additional indication elements, which represent the position of the switching contacts and the state of the energy store, are adjacently arranged in an axial manner such that they can pivot and are provided with interacting drives in order to effect a forced drive of the indication element for indicating the readiness for closing when the position of the switching contacts or the state of the energy store does not enable or permit a closing of the power circuit breaker.

Description:
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/DE00/04203 which has an International filing date of Nov. 22, 2000, which designated the United States of America, and which claims priority on German Application number DE 19957391.3 filed Nov. 24, 1999, the entire contents of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention generally relates to a device for controlling the closing of a power circuit breaker according to operational parameters. Preferably, it relates to a power circuit breaker including switching contacts, an energy store for transferring the switching contacts from an opening position into a closing position, a latching device for maintaining a tensioned state of the energy store and at least one closing actuator for releasing the latching device and enabling the energy store. Arranged in the path of the force transfer from the closing actuator to the latching device, may be a coupling element, which can be moved into an active position and an inactive position. Each of the parameters may cause the coupling element to be transferred into the inactive position, in which the force transfer from the closing actuator to the latching device is interrupted. An indicating element, which is dependent on the coupling element and can be moved into two positions corresponding to the states, may be provided for visually presenting the states of “ready for closing” and “not ready for closing” 
     BACKGROUND OF THE INVENTION 
     A device for controlling a power circuit breaker is disclosed by DE 43 33 828 C1. It makes it possible for a user of the power circuit breaker to verify that the power circuit breaker can be closed by viewing the separate indicating element. 
     At the same time, the device prevents the energy store from being enabled in spite of activation of a closing actuator, such as a manually operated pushbutton or electromagnet, if one of the conditions is not satisfied. Since all the features or parameters which oppose closing of the power circuit breaker can be considered, the device makes an important contribution to the safety of the users of power circuit breakers and to the protection of electrical switchgear. 
     SUMMARY OF THE INVENTION 
     An embodiment of the invention is based on an object of providing a device which has a simplified construction and smaller dimensions. As a result, such a device may make it possible to use the advantages of the indication of closing readiness for all power circuit breakers which have a stored-energy mechanism. 
     The stated object is achieved according to an embodiment of the invention by at least one of the following further features: 
     the indicating element for closing readiness has working surfaces which can be acted on by the operational parameters and is able to be transferred by each of the parameters, counter to the action of a restoring force, from the “ready for closing” position into the; “not ready for closing” position, 
     the indicating element and the coupling element have interacting working surfaces for transferring the coupling element into its inactive position when the indicating element assumes the “not ready for closing” position. 
     Consequently, the indicating element for closing readiness additionally has the logical OR function for the operational parameters. This has an advantageous effect on the space requirement of the device. 
     Within the scope of an embodiment of the invention, the indicating element for closing readiness can be moved about a pivot axis, the coupling element, which is designed in the manner of a lever, can be displaced in its longitudinal direction by the closing actuator and has a frame-like middle part, reaching over a fixed guiding surface with a clearance and being able to be transferred by two drivers of the indicating element into the active position or the inactive position. This likewise has the effect of saving unit volume. 
     In connection with the design explained above of the indicating element for closing readiness, the fixed guiding surface may be formed by an attachment which is arranged concentrically in relation to the pivot axis of the indicating element and against which one frame leg of the middle part of the coupling element bears in its active position, and if the drivers of the indicating element for closing readiness reach over the other frame leg of the middle part. This has the effect that the coupling element is taken up and guided in such a way that, on the one hand, it can be displaced in its longitudinal direction by a closing actuator and, on the other hand, it can be pivoted under the influence of the: indicating element to assume the active or inactive position. 
     In the case of power circuit breakers, it is also possible in connection with an embodiment of the invention for an indicating element representing the state of the energy store and a further indicating element, representing the position of the switching contacts, to be provided in addition to the indicating element for closing readiness. Within the scope of an embodiment of the invention, it can be provided that said additional indicating elements are likewise arranged such that they can be moved about the pivot axis of the indicating element for closing readiness and that the additional indicating elements each have a driver for driving the indicating element for closing readiness. This achieves, in a particularly simple and therefore space-saving way, the effect that two of the conditions for closing readiness of the power circuit breaker, that is “switching contacts open” and “energy store tensioned”, become effective directly, without relying on mechanical devices. 
     It can contribute to a compact type of construction of the device and at the same time to a reliable function that the closing latching lever bears a lug for direct forcible actuation of the indicating element for the state of the energy store in both positions (“tensioned” and “empty”) and for actuating the indicating element for closing readiness only in the “not ready for closing” direction. 
     In this case it proves to be expedient to arrange the indicating element for closing readiness centrally between the indicating elements for the switching position and for the state of the energy store, thereby creating a mechanically compact arrangement which allows the user an overview and makes it possible to see the state of the power circuit breaker at a glance. 
     Depending on the conditions at the place where a power circuit breaker is installed, there may be a different number of mechanical parameters to be supplied to the device according to an embodiment of the invention, as explained in the aforementioned DE 43 33 828 C1. In this case, it may prove to be advantageous to provide for the supplying of parameters based on the state of actuating magnets an intermediate shaft which has a first lever arm, interacting with the indicating element for closing readiness, and a second lever arm, interacting with a latching device controlling the opening of the power circuit breaker. This intermediate shaft allows, on the one hand, a separation of the parameters existing in the power circuit breaker itself from those which originate outside the power circuit breaker, for example “door of the switchgear cell open” or “power circuit breaker drawn out”. In addition, the intermediate shaft makes possible a desired mechanical transmission ratio for adapting the stroke and force of actuating magnets to the device according to an embodiment of the invention and a desired spatial position in relation to the indicating element for closing readiness and the coupling element. 
     The intermediate shaft also offers the possibility of assigning an opening actuator to the device. This can take place by the intermediate shaft bearing as a third lever arm an opening lever arm, which can be acted on by an opening actuator. This can take place directly or with an auxiliary lever interposed, if the spatial position of the element to be coupled makes this appear to be necessary. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in more detail below on the basis of the exemplary embodiment represented in the figures. 
     FIG. 1 shows a device for controlling the closing readiness of a low-voltage power circuit breaker, some components of the power circuit breaker being represented in a schematically simplified form. 
     A modified exemplary embodiment of a device for controlling closing readiness is shown in FIG. 2 in a representation corresponding to FIG.  1 . 
     In FIGS. 3,  4 ,  5  and  6 , a group of indicating elements are shown separately in different operating states as a component part of the device according to FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Shown in FIG. 1, as a component part of a low-voltage power circuit breaker, is an energy store  1  in the form of a compression spring, which can be transferred into a tensioned state in a known way by use of a closing latching lever  2  and is kept in the tensioned state by a latching device  3 . The latching device  3  includes a rotatably mounted closing half-shaft  4 , which interacts with a pivotably mounted closing latching lever  2 . The closing half-shaft  4  of the latching device  3  is pretensioned into the position shown by a tension spring  5 , whereby the energy store  1  is kept in the charged state. A clockwise rotation of the closing half-shaft  4  causes sliding off of the latching surface on the closing latching lever  2  and, as a result, enabling of the energy store I to close the indicated switching contact  6 . 
     A further latching device  7  is constructed in a way similar to the latching device  3  and accordingly has an opening half-shaft  10  and an opening latching lever  11 . If the opening half-shaft  10  is rotated out of its position of rest, counter to the action of a tension spring  12 , the opening latching lever  11  slides off the opening half-shaft  10  and causes in a known way the opening of the switching contact  6 . The mechanical connections between the opening latching lever  11  and the switching contact  6  have been omitted to simplify the representation, since they are not required for understanding the invention and can be the same or similar to those of known power circuit breakers. 
     The device to be described in more detail below, according to FIG. 1, serves the purpose of making it possible to enable the closing latching lever  2  to close the switching contact  6  only if all the conditions to allow closing to be carried out are satisfied and closing is permissible from the aspect of user safety and technical reliability. A series of parameters which are of significance in this context are described in DE 43 33 828 C1, mentioned at the beginning. Named there as examples of operational parameters are: 
     A position of the operating shaft, 
     B removal of the overcurrent trip from the power circuit breaker, 
     C blocking with respect to further power circuit breakers of a switchgear, 
     D position of the door of a switchgear cell accommodating the power circuit breaker, 
     E position of the power circuit breaker in the slide-in frame and the state of the actuating magnets M 1 , M 2  and S. 
     All the named parameters are brought together in the case of the device shown by a pivotably mounted indicating element  13  for closing readiness, which has an indicating surface  14  for the visual presentation of indicating readiness in a window  15  of an operating face  16  of the power circuit breaker. A tension spring  17  pretensions the indicating element  13  into the position shown, which corresponds to the position of existing closing readiness. An extension arm  20 , opposite from the indicating surface  14 , serves for introducing mechanical movements which correspond to the stated operational parameters of the power circuit breaker. In this respect, the supplying of the parameters A to E is represented in FIG. 1 by an arrow  21  directed at the extension arm  20 . As can be seen, each of these parameters causes pivoting of the indicating element  13 , counter to the action of the restoring spring  17 , and consequently counterclockwise into the position indicated by dot-dashed lines, by which absent closing readiness is indicated in the viewing window  15 . 
     The same effect, that is to say the “not ready for closing” indication, is brought about by an intermediate shaft  22 , on which there is arranged a lever arm  23  for introducing the parameters-M 1  and M 2  in the direction of an arrow  24  and a further lever arm  25  for acting on the extension arm  20 . A further lever arm  26 , arranged opposite from the lever arms  23  and  25  of the intermediate shaft  22 , interacts with the opening half-shaft  10 . In this way, the parameters M 1  and M 2  at the same time cause the desired opening of the switching contact  6  and the “not ready for closing” indication of the indicating element  13 . 
     Interacting with the indicating element  13  for closing readiness is a coupling element  27 , which is designed overall in the manner of a lever and is arranged movably at its lower end about a pivot bearing  30 . The pivot bearing  30  is not fixed, but movable on a tilting lever  31  with a fixed pivot bearing  32 . At its end opposite from the pivot bearing  30 , the coupling element  27  reaches with a working surface  33 , designed in the manner of a hook, over a lever arm  34  mounted on the closing half-shaft  4 . If the coupling element  27  is pivoted clockwise about the pivot bearing  30  in the direction of an arrow  35 , the working surface  33  disengages from the lever arm  34 . In this case, all the movements acting on the coupling element  27  in the longitudinal direction of the latter which are exerted by closing actuators remain without effect on the closing half-shaft  4 . In the example shown, closing actuators  36  and S (arrow  26 ) arc shown. The closing actuator  36  is formed by a closing pushbutton, which is located on the operator console  16  of the power circuit breaker, can be operated manually and acts on the aforementioned tilting lever  31 . As a result, the tilting lever  31  is pivoted counterclockwise, counter to the action of a restoring spring  37 , about its pivot bearing  32  and, as a result, the pivot bearing  30  of the coupling element  27  is displaced downward. If the working surface  33  is in this case in the effective range of the lever arm  34 , the closing half-shaft  4  is driven along with it. The same happens if the further closing actuator S, formed by a call-up magnet, acts on the coupling element  27  in the direction of the arrow  38 . 
     As already mentioned, the closing actuators  36  and S remain without effect if the coupling element  27  is pivoted clockwise and, as a result, the working surface  33  is moved away from the lever arm  34 . To cause this movement, the coupling element  27  has a middle part  40 , formed in the manner of a frame, which has two frame legs  41  and  42  extending approximately parallel and in the longitudinal direction of the coupling element  27 . Of these, the frame leg  41  is reached over, somewhat in the manner of a fork, by two drivers  43  and  44  located on the extension arm  20  of the indicating element  13 , while the further frame leg  42  bears against a concentric attachment  45  of the indicating element  13  in the state of rest of the coupling element  27 . 
     The position of the drivers  43  and  44  between the pivot bearing  30  and the working; surface  33  of the coupling element  37  achieves the effect that the described pivoting of the indicating element  13  counterclockwise into its “not ready for closing” position moves the coupling element clockwise about its pivot bearing  30  and, as a result, disengages the working surface  33  from the lever arm  34  of the closing half-shaft  4 . Conversely, the coupling element  27  is returned to the position shown by solid lines in FIG. 1 as soon as the indicating element  13  returns to its “ready for closing” position. 
     The power circuit breaker considered in connection with the invention has in addition to the indicating element  13  for closing readiness two further indicating elements  46  and  47 , which visually illustrate to a user the switching state of the switching contact  6  or the state of the energy store  1 . According to FIGS. 3,  4 ,  5  and  6 , said three indicating elements  13 ,  46  and  47  are arranged adjacently, the additional indicating elements  46  and  47  being pivotable in the same way as the indicating element  13  about said pivot axis. The additional indicating elements  46  and  47 , arranged on either side of the indicating element  13  for closing readiness, each have a driver  50  and  51 , respectively, extending axially in the direction of the indicating element  13  in the middle. Interacting with these drivers  50  and  51  are drivers  52  and  53 , likewise extending axially from the indicating element  13  to both sides. This achieves the effect of forcibly driving the indicating element  13  for closing readiness into the “not ready for closing” position if the switching contacts are not opened or if the energy store is not charged. 
     Let us firstly consider FIG. 3, which indicates the ready for closing state. In this case there appear next to one another in windows on the operator console  16  (FIG. 1) on the left the symbol “0” for the “switching contacts open” state, in the center the “OK” indication for existing closing readiness and on the right the known symbol of a spring for the “energy store tensioned” state, 
     Indicated in FIG. 4 is the operating state in which, although the energy store is still tensioned and the indicating element  47  accordingly assumes the same position as in FIG. 2, the switching contacts  6  are closed. This has the consequence that the indicating element  46  shows the symbol “I” (ON) and therefore the indicating element  13  has been actuated by means of its driver  52  by the driver  50  of the indicating element  46  and indicates: “not ready for closing”. 
     In the operating state according to FIG. 5, the indicating element  47  shows “energy store empty” (= symbol of relaxed spring) and the indicating element  46  shows “0” (= OFF switching position). In this case, the indicating element  13  shows “not ready for closing” on account of the interaction of the drivers  51  and  53 . 
     The indicating element  13  likewise indicates “not ready for closing” in the position according to FIG. 6, which represents the state in which the switching contacts  6  are closed (= ON switching position) and the energy store  1  is discharged (= “relaxed spring” symbol). To supply the device according to FIG. 1 with an opening command, there is provided an opening actuator  54 , which acts in a suitable way on a pivotably mounted deflecting lever  55 , which is pretensioned into its position of rest by a restoring spring  56 . A slotted slide  57 , connected in an articulated manner to the deflecting lever, reaches over a driver pin  58 , mounted on the lever arm, in such a way that the opening half-shaft  10  can be rotated counterclockwise by the lever arm  26  and, as a result, the opening latching lever  11  can be released. 
     Represented in FIG. 2 is a modified exemplary embodiment in which direct actuation of the indicating elements  13  and  47  by the closing latching lever  2  is provided. For this purpose, the closing latching lever  2  is provided with a lug  60 , which interacts with the driver  43 . As can be seen, this only happens in that direction of movement which represents the ON state, in which the energy store  1  is discharged and, accordingly, there is no longer readiness for closing. As a result, the indicating element  13  for closing readiness is forcibly brought into the “not ready for closing” position. This is represented in FIG. 3 by a coupling linkage  61  and an arrow  62 . The indicating element  47  (FIGS. 3-6) for the state of the energy store  1  is likewise forcibly actuated. This is likewise schematically illustrated in FIG. 3 by a double-headed arrow  63 , which illustrates the actuation of the indicating element  47  by the closing latching lever  2  in both directions of movement. 
     A further modification with respect to the exemplary embodiment according to FIG. 2 is given in FIG. 3 with regard to the opening actuator  54 . This acts on one lever arm of a two-armed auxiliary lever  64 , which is pretensioned into a position of rest by a compression spring  65 , which acts on the second lever arm of the auxiliary lever  64 . In addition to the lever arms  25  and  26 , the intermediate shaft  22  bears an opening lever arm  66 , on which the auxiliary lever  64  acts when the opening actuator  54  is actuated. As can be seen, the auxiliary lever  64  and the opening lever arm  66  make it possible to actuate the intermediate shaft  22  by the opening actuator  54  in spite of a certain distance and different directions of action of the two elements. Under some circumstances it may be possible to omit the auxiliary lever  64 , including its mounting and its restoring spring  65 , if the opening actuator  54  can be made to act directly on the opening lever arm  66  of the auxiliary shaft  22 . 
     Shown in FIGS. 1 and 2 as a further detail is an auxiliary switch  67 , which can be actuated by the indicating element  13  for closing readiness. The auxiliary switch  67  can be used in a known way for electrically processing or indicating the closing readiness of a power circuit breaker equipped with the device described. 
     The entire device described, including the closing and opening actuators  36  and  54  and also the indicating elements  13 ,  46  and  47 , can be produced as an extremely space-saving and mechanically reliable assembly. This makes it easier for all power circuit breakers provided with an energy store to be equipped with a device according to an embodiment of the invention. 
     List of designations 
       1  energy store 
       2  closing latching lever 
       4  latching device 
       4  closing half-shaft 
       3  latching device 
       5  tension spring 
       6  switching contacts 
       7  latching device 
       10  opening half-shaft 
       11  opening latching lever 
       13  indicating element for closing readiness 
       12  tension spring 
       14  indicating surface 
       15  window 
       16  operator console 
       17  tension spring 
       20  extension arm 
       21  arrow 
       22  intermediate shaft 
       23 ,  25  lever arm 
       24  arrow 
       26  lever arm 
       27  coupling element 
       30  pivot bearing 
       31  tilting lever 
       32  pivot bearing of the tilting lever  31   
       33  working surface 
       34  lever arm 
       35  arrow for pivoting 
       36 , S closing actuator 
       37  restoring spring 
       38  restoring spring 
       40  frame-like middle part 
       41 ,  42  frame legs 
       41  middle part 
       42  frame leg 
       43 ,  44  drivers 
       45  attachment 
       46  indicating element for the switching state (ON/OFF) 
       47  indicating element for state of the energy store  1   
       50  driver on the indicating element  46   
       51  driver on the indicating element  47   
       52 ,  53  driver on the indicating element  13   
       54  opening actuator 
       55  deflecting lever 
       56  restoring spring for deflecting lever  55   
       57  slotted slide 
       58  driver pin 
       60  lug on the on latching lever  2   
       61  coupling linkage for indicating element  47   
       62  arrow for actuation of the indicating element  13   
       63  double-headed arrow for actuation of the indicating element  47   
       64  auxiliary lever 
       65  restoring spring for auxiliary lever  63   
       66  opening lever arm on the intermediate shaft  22   
       67  auxiliary switch on the indicating element  13   
     M 1 , M 2  parameters 
     M 1 , M 2 , S actuating magnet 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.