Patent Publication Number: US-10312045-B2

Title: Interruption apparatus employing actuator having movable engagement element

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The instant application claims priority from U.S. patent application Ser. No. 14/881,223 filed Oct. 13, 2015, the disclosures of which are incorporated herein by reference. 
     BACKGROUND 
     Field 
     The disclosed and claimed concept relates generally to electrical interruption equipment and, more particularly, to an interruption apparatus that employs an actuator having a movable engagement element. 
     Related Art 
     Numerous types of circuit interruption devices are known in the relevant art and include circuit breakers, vacuum interrupters, and numerous other devices that interrupt a circuit. While such devices have been generally effective for their intended purposes, they have not been without limitation. 
     As is generally understood, a circuit interruption device typically includes a conductor having a set of separable contacts within it, and the conductor forms a part of a circuit. When the separable contacts are electrically connected together, the circuit is in a CLOSED state, and when the contacts are electrically separated from one another, the circuit is in OPEN state. A circuit breaker or other interrupter typically also includes some type of trip unit that employs stored spring energy which is rapidly released to move the separable contacts apart in response to an overcurrent condition or an under-voltage condition or other appropriate condition. 
     However, as the needs of a given circuit or set of circuits become more complex, the cost of the equipment used to protect such circuitry correspondingly increases. Improvements thus would be desired. 
     SUMMARY 
     An improved interruption apparatus includes a plurality of poles, with each of the poles including an actuator. In one embodiment, the actuator can be a fuse having a movable engagement element, and in another embodiment the actuator can be an electric coil that is operable to move a movable engagement element. The interruption apparatus has a single trip unit, and the engagement element of any actuator can actuate the trip unit to move all of the poles from a CLOSED state to an OPEN state. 
     Accordingly, an aspect of the disclosed and claimed concept is to provide an improved interruption apparatus having a plurality of poles, with each pole having its own actuator, and with the interruption apparatus having a single trip unit that is actuatable by any one of the actuators to open all of the poles. 
     Another aspect of the disclosed and claimed concept is to provide an improved multi-pole interruption apparatus at a reduced cost. 
     Another aspect of the disclosed and claimed concept is to provide an improved multi-pole interruption apparatus having reduced mechanical complexity. 
     Accordingly, an aspect of the disclosed and claimed concept is to provide an improved interruption apparatus that can be generally stated as including a plurality of conductors, a contact arm apparatus that can be generally stated as including a plurality of contact arms, a contact apparatus that can be generally stated as including a plurality of sets of separable contacts, each set of separable contacts of the plurality of sets of separable contacts comprising a movable contact and a stationary contact, the movable contact being situated on a corresponding contact arm of the plurality of contact arms, the stationary contact being electrically connected with a first portion of a corresponding conductor of the plurality of conductors and the movable contact being electrically connected with a second portion of the corresponding conductor, a trip unit that is operably connected with each contact arm of the plurality of contact arms, the trip unit being movable between an ON condition wherein the plurality of contact arms are positioned such that the plurality of sets of separable contacts are each in a CLOSED state and an OFF condition wherein the plurality of contact arms are positioned such that the plurality of sets of separable contacts are each in an OPEN state, a plurality of actuators, each actuator of the plurality of actuators being electrically connected with a corresponding conductor of the plurality of conductors, each actuator of the plurality of actuators can be generally stated as including a support, a detector, and an engagement element, the engagement element being situated on the support and being movable between a first position with respect to the support and a second position with respect to the support, the first position and the second position being different than one another, the engagement element in one of the first position and the second position being engageable with the operating mechanism when the operating mechanism is in the ON condition and, responsive to a detector of an actuator of the plurality of actuators experiencing a predetermined event, the corresponding engagement element moving from the first position toward the second position and undergoing a change in its state of engagement with the operating mechanism by becoming one of engaged with the operating mechanism and disengaged with the operating mechanism and thereby triggering the trip unit to release the operating mechanism to move from the ON condition to the OFF condition. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A further understanding of the disclosed and claimed concept can be gained from the following Description when read in conjunction with the accompanying drawings in which: 
         FIG. 1  is a schematic depiction of an improved interruption apparatus in accordance with a first embodiment of the disclosed and claimed concept; 
         FIG. 2  is a depiction of an actuator of the interruption apparatus of  FIG. 1  in a first state; 
         FIG. 3  is a view similar to  FIG. 2 , except depicting the actuator in a second state; 
         FIG. 4A  is diagrammatic depiction of the interruption apparatus of  FIG. 1  in an ON condition 
         FIG. 4B  is a view similar to  FIG. 4A , except depicting an actuator having moved from the first state to the second state; 
         FIG. 4C  is a view similar to  FIG. 4B , except depicting the interruption apparatus in an OFF condition; and 
         FIG. 5  is a schematic depiction of an improved interruption apparatus in accordance with a second embodiment of the disclosed and claimed concept. 
     
    
    
     Similar numerals refer to similar parts throughout the specification. 
     DESCRIPTION 
     An improved interruption apparatus  4  in accordance with the disclosed and claimed concept is depicted schematically in  FIG. 1 . The interruption apparatus  4  is an electrical interruption apparatus that includes a plurality of poles that are indicated at the numerals  8 A,  8 B, and  8 C, it being noted that such poles may be individually or collectively referred to herein with the numeral  8 . The poles  8  are electrically separate from one another. While the interruption apparatus  4  is depicted herein as including three of the poles  8 , it is understood that in other embodiments the interruption apparatus  4  can include two poles or more than three poles without departing from the present concept. As will be set forth in greater detail below, the interruption apparatus  4  is capable of being manufactured in a cost advantageous fashion because it employs inexpensive devices to detect the conditions on each pole  8 , and any of these inexpensive devices can actuate a single mechanism that moves all of the poles from the CLOSED state to the OPEN state to thereby move the interruption apparatus  4  from an ON condition to an OFF condition. 
     The interruption apparatus  4  includes an actuator apparatus  12  that includes a plurality of actuators that are indicated at the numerals  16 A,  16 B, and  16 C, it being noted that the actuators can be individually or collectively referred to herein with the numeral  16 . A corresponding one of the actuators  16  is provided for each pole  8 , and the actuators  16  are thus three in quantity. As will be set forth in greater detail below, the exemplary actuators  16  are each in the exemplary form of a fuse. 
     As can be further seen in  FIG. 1 , each pole  8  includes a conductor  20  that can be said to include a line end  24  and a load end  28  opposite one another that are connectable with a circuit to provide protection for the circuit. The poles  8  are depicted in  FIG. 1  as each being in a CLOSED state, meaning that each pole  8  is electrically conductive between the line and load ends  24  and  28 . 
     The interruption apparatus  4  further includes a contact arm apparatus  32  that includes a plurality of contact arms  36 , with each pole  8  including its own corresponding contact arm  36 . Each pole  8  further includes a set of separable contacts  40 . Each set of separable contacts  40  includes a stationary contact  44  and a movable contact  48 . The movable contact  48  is affixed to the corresponding contact arm  36  of the pole  8 , and the stationary contact  44  is affixed to another portion of the corresponding conductor  20  of the pole  8 . The stationary and movable contacts  44  and  48  can be of any form, including blade and socket disconnect-type elements and the like, without departing from the present concept. Each set of separable contacts  40  is depicted in  FIG. 1  as being in an electrically connected condition but are depicted elsewhere herein, such as in  FIG. 4C , in an electrically disconnected condition. 
     The interruption apparatus  4  further includes a single trip unit  52  that includes a trip cam  56  which is operably associated with each of the poles  8 . The trip unit  52  includes one or more springs that are used to store mechanical energy and further includes a latch that is operable to rapidly release the stored mechanical energy to separate the sets of separable contacts  40 . 
     As will be set forth in greater detail, when the trip cam  56  is engaged or otherwise actuated by any of the actuators  16 A,  16 B, and  16 C, the trip cam  56  triggers the trip unit  52  to move all of the contact arms  36  of the contact arm apparatus  32  to thereby move the sets of separable contacts  40  from the electrically connected condition of  FIGS. 1 and 4A  to an electrically disconnected condition, such as is depicted in  FIG. 4C . In the exemplary embodiment presented herein, the trip cam  56  does so by releasing the latch of the trip unit  52  which rapidly releases the stored spring energy in the trip unit  52  to move the contact arms  36 . It is understood, however, that the specific configuration of the trip unit  52  that is described herein is exemplary in nature and is not intended to be limiting. 
     As can be seen in  FIGS. 2 and 3 , the actuators  16  each include a support  60  and a movable engagement element  64 . The engagement element  64  is situated on the support  60  and is movable with respect to the support  60  between a retracted state, such as is depicted generally in  FIG. 2 , and an extended state such as is depicted generally in  FIG. 3 . Each actuator  16  further includes a fusible element  68  that functions as a detector which, upon experiencing a predetermined overcurrent or other condition on its associated pole  8 , undergoes a deformation such as by melting or otherwise fusing. The actuators  16  further each include a spring  72  that serves as a biasing element that biases the engagement element  64  toward the extended state. 
     The exemplary fusible element  68  is depicted in  FIG. 2  in an intact, i.e., unfused, condition wherein it retains the engagement element  64  in the retracted state and thus overcomes the bias of the spring  72 . The fusible element  68  is depicted in  FIG. 3  as having experienced a predetermined overcurrent condition or other condition and as having undergone deformation, such as by melting or fusing and thereby releasing the bias of the spring  72 . This permits the spring  72  to move the engagement element  64  from the retracted state of  FIG. 2  to the extended state of  FIG. 3 . It is understood that the exemplary depiction of the actuator  16  in  FIGS. 2 and 3  is meant to be functional only and not limiting as to the particular configuration of the actuators  16 . Rather, the actuators  16  can be in any of a variety of configurations that cause the engagement element  64  to move between two states or positions when a detector experiences a predetermined condition on the associated pole  8 . 
     As can be seen in  FIG. 1 , the actuators  16 A,  16 B, and  16 C are each electrically connected with the corresponding conductor  20  of the poles  8 A,  8 B, and  8 C, respectively. While the actuators  16  are each depicted in  FIG. 1  in an exemplary fashion as being connected in series with other conductive components of the corresponding conductors  20 , it is understood that the actuators  16  could be otherwise connected with the conductors  20  while still detecting overcurrent conditions or other conditions on each of the poles  8  without departing from the present concept. 
     The ON condition of the interruption apparatus  4  that is depicted in  FIG. 1  is also diagrammatically depicted in  FIG. 4A . When any of the actuators  16  detects or otherwise experiences a predetermined condition such as an overcurrent condition or other condition on its associated pole  8 , the corresponding engagement element  64  is released to move from its retracted state to its extended state. More specifically,  FIG. 4B  depicts the actuator  16 C as having its fusible element  68  in a fused or otherwise deformed state responsive to having experienced the overcurrent or other condition on the pole  8 C, thereby releasing the corresponding engagement element  64  to be biased by the spring  72  from the retracted state of  FIG. 4A  to the extended state of  4 B where the engagement element  64  has engaged the trip cam  56 . 
     In  FIG. 4C , the trip cam  56  that has been engaged by the engagement element  64  of the actuator  16 C has released the latch of the trip unit  52  to cause the trip unit  52  to move the contact arms  36  and thus the movable contacts  48  situated thereon to all be electrically disconnected from the associated stationary contacts  44 . As such,  FIG. 4C  depicts each of the poles  8  as being in the OPEN state such that the interruption apparatus  4  is in the OFF condition. While the actuator  16 C is depicted in  FIGS. 4B and 4C  as having experienced an overcurrent or other predetermined condition on the pole  8 C and thus having released its engagement element  64  to engage the trip cam  56  to thereby move all of the poles  8  to the OPEN state, it is noted that any one of the actuators  16 A,  16 B, and  16 C could individually engage the trip cam  56  to simultaneously move all of the poles  8  to the OPEN state. 
     It thus can be seen that the actuators  16 A,  16 B, and  16 C are each separately responsive to an overcurrent condition or other appropriate condition on the associated pole  8 A,  8 B, and  8 C, respectively. Accordingly, any one of the actuators  16 A,  16 B, and  16 C that may experience such an overcurrent condition or other predetermined condition can individually engage the trip cam  56  which, in turn, causes the trip unit  52  to open all of the poles  8 , and this is by operation of only the individual trip unit  52 . 
     Employing the individual trip unit  52  to simultaneously operate all three of the poles  8  saves expense by avoiding the need to provide a separate trip unit for each pole  8 . Rather, separate actuators  16 A,  16 B, and  16 C are provided for each of the poles  8 . The actuators  16  are each individually operable in response to a predetermined condition occurring on its associated pole  8  to engage the trip cam  56  to actuate the individual trip unit  52  to move all of the poles  8  to the OPEN state to move the interruption apparatus to the OFF condition. That is, the use of multiple inexpensive and replaceable actuators  16  and only a single trip unit  52  is advantageously less expensive than providing a separate trip unit  52  for each pole  8 , which saves expense, and which is thus desirable. 
     An improved interruption apparatus  104  in accordance with a second embodiment of the disclosed and claimed, concept is depicted in a schematic fashion in  FIG. 5 . The interruption apparatus  104  is similar to the interruption apparatus  4 , except that the interruption apparatus  104  employs a different actuator apparatus having a plurality of actuators  116 A,  116 B, and  116 C. It is noted that the actuators may be individually or collectively referred to herein with the numeral  116 . 
     The actuators  116  each include a support  160  and a movable engagement  164  that is movable with respect to the support  160  between a retracted state and an extended state, such as is provided by the actuators  16 . It is noted, however, that each support  160  employs a controller  168  that is connected with a corresponding electrical coil  172 . In the depicted exemplary embodiment, the controller  168  is electrically connected with its associated pole  108  and, in response to experiencing a predetermined overcurrent or other condition on the pole  108 , energizes the coil  172 . The energized coil  172  causes the engagement element  164  to move from the retracted state of  FIG. 5  to the extended state that is depicted in dashed lines in  FIG. 5 . As before, any one of the engagement elements  164  can individually engage a trip cam  156  of the interruption apparatus  104  that will trigger an individual trip unit  152  to move the plurality of contact arms of the interruption apparatus  104  to move all of the poles  108  to the OPEN state. 
     While the controllers  168  are depicted in  FIG. 5  as each being electrically connected with an associated pole  108  and being operable to energize the associated coil  172 , it is noted that in other embodiments controllers  168  may be otherwise configured or may be entirely absent. That is, the coil  172  may itself be electrically connected with the associated pole  108  depending upon the needed configuration. 
     Since the controller  168  and the coil  172  serve as a detector and do not permanently deform by fusing, the engagement element  164  can be reset to the retracted state. As such, the controller  168  and the coil  172  can again be used to detect a predetermined condition on its associated pole  108  and responsively move the associated engagement element  164  from the retracted state to the extended state. Any one of the actuators  116  is individually operable to move its associated engagement element  164  to the extended state to thereby engage the trip cam  156  and cause the trip unit  152  to move all of the poles  108  to the OPEN state, in a fashion similar to the interruption apparatus  104 . Other variations of the concept presented herein will be apparent to one of ordinary skill in the art. 
     While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.