Patent Application
20090257174
Aspects of the present disclosure are directed to draw-out type circuit breakers and, more particularly, to draw-out type circuit breakers in which a secondary disconnect terminal block is rotatable.
Circuit breakers are capable of interrupting high ampere current in various industrial, commercial or personal electrical applications and may be categorized generally as draw-out types of circuit breakers and fixed types of circuit breakers. In that capacity, both types of circuit breakers may be attached to circuitry and, in particular, to a switchboard with limited spatial capacity. As such, it is desirable to construct both types of circuit breakers with increasingly smaller and smaller components without sacrificing accessibility.
In conventional draw-out types of circuit breakers, compact size has been accomplished by forming a cassette to be attached to the main power circuitry, and a circuit breaker that is drawn into and out from the cassette. For secondary control circuits, the cassette is provided with a fixed secondary terminal block that cooperates with a fixed secondary terminal block of the circuit breaker to form appropriate electrical connections for the secondary control circuits of the circuit breaker. However, given the above-noted spatial limitations and since the terminal block of the cassette is fixed relative to the cassette in the conventional circuit breakers, it may be difficult or impossible for an operator to conduct wiring processes of the terminal block of the cassette in a completed installation.
In accordance with an aspect of the invention, a circuit breaker apparatus is provided and includes a cassette, including a housing surface, a cassette-side terminal block rotatably attached to the housing surface of the cassette, including first terminal housings arrayed thereon, and being rotatable between at least a first position and a second position, a circuit breaker configured to be removably inserted into the cassette during a rack-in operation, and a circuit breaker-side terminal block attached to the circuit breaker with second terminal housings arrayed thereon to positionally cooperate with the first terminal housings when the cassette-side terminal block is in the first position and when the rack-in operation is at least partially complete.
In accordance with another aspect of the invention, a circuit breaker apparatus is provided and includes a cassette having an external structure, including a housing surface, a cassette-side terminal block attached to the housing surface via a hinge about which the cassette-side terminal block rotates between at least a service position thereof and a wiring position thereof, a set of female terminal housings arrayed on the cassette-side terminal block, a circuit breaker configured to be removably inserted into a connected position with the cassette during a rack-in operation, a circuit breaker-side terminal block attached to the circuit breaker, and a set of male terminal housings arrayed on the circuit breaker-side terminal block to positionally cooperate with the female terminal housings when the cassette-side terminal block is in the service position and when the rack-in operation is at least partially complete.
In accordance with another aspect of the invention, a circuit breaker apparatus is provided and includes a cassette having an external structure, including a housing surface, a cassette-side terminal block attached to the housing surface via a hinge about which the cassette-side terminal block rotates between at least a service position thereof and a wiring position thereof, a set of female terminal housings arrayed on the cassette-side terminal block, a circuit breaker configured to be removably inserted from a disconnected position and into at least a test position and a connected position with the cassette during a rack-in operation, a circuit breaker-side terminal block attached to the circuit breaker, and a set of male terminal housings arrayed on the circuit breaker-side terminal block to positionally cooperate with the female terminal housings when the cassette-side terminal block is in the service position and when the rack-in operation is at least in the test position and/or the connected position.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other aspects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
With reference to
Here, while housing surface 13 is the top surface of the cassette 11, it is understood that embodiments of the invention exist in which the cassette-side terminal block 30 is attached to other housing surfaces, for example, housing surfaces 12 or 14, in a similar manner as described above. For example, as shown in
With reference still to
Each of the female terminal housings 40 may include a screw type terminal having a terminal screw 42 that may be driven by the operator during wiring processes with the circuit breaker 20 at an external position of a disconnected position. These wiring processes may be carried out by the operator at a front of the cassette 11 and by way of the cassette-side terminal block 30 being rotated with respect to the housing surface to which it is attached into the wiring position 34 at which each terminal screw 42 is accessible. To this end, the protection covering 45 may include through holes 46 defined therein to provide the operator with access to corresponding terminal screws 42.
With reference back to
A circuit breaker-side terminal block 50 is attached to a surface 23 of the circuit breaker 20. A set of male terminal housings 60 is arrayed on the circuit breaker-side terminal block 50. The set of male terminal housings 60 is positioned by the circuit breaker-side terminal block 50 to positionally cooperate with the female terminal housings 40. In particular, the set of male terminal housings 60 positionally cooperates with the female terminal housings 40 when the cassette-side terminal block 30 is in the service position 33 and when the rack-in operation has been completed to, at least, the test position 35 and/or the connected position 36. Further, the set of male terminals 60 is positionally non-cooperative with the female terminal housings 40 when the cassette-side terminal block 30 is in the wiring position 34.
With reference to
Still referring to
With reference to
With reference to
In accordance with an embodiment of the invention, in order to facilitate the removable insertion of the circuit breaker 20 into the cassette 11, the cassette-side terminal block 30 may be removable from the cassette 11 and the female terminal housings 40 may be configured to float relative to the housing surface 13. The removal of the cassette-side terminal block 30 is accomplished by removing a terminal block screw (not shown) and then lifting the cassette-side terminal block 30 from the pivot bosses 31. The floating of the female terminal housings 40 is accomplished by connecting a block of female terminal housings 40 to a bracket of the cassette-side terminal block 30 having a slot defined therein, into which a projection of the cassette-side terminal block 30 extends, with stepped screws. In this manner, the stepped screws tighten the cassette-side terminal block 30 to the bracket with the projection cooperating with the slot to guide the floating of the block of the female terminal housings 40.
With reference to
In an embodiment of the invention, each of the biased locking elements 110 and 120 may respectively include alignment members 130 that are configured to cooperate during the rack-in operation and locking members 140 that are configured to cooperate once the circuit breaker 20 reaches the connected position 36. Here, both the alignment members 130 and the locking members 140 may be spring loaded. That is, the alignment members 130 may include relatively steeply angled surfaces 131 of plastic extensions 132 attached to the cassette-side terminal block 30 and relatively steeply angled surfaces 133 of elastic extensions 134 attached to the circuit breaker-side terminal block 50. Similarly, the locking members 140 may include relatively shallow angled surfaces 135 of the plastic extensions 132 and relatively shallow angled surfaces 136 of elastic extensions 134.
In accordance with various aspects of the present invention, a number of male and female terminals that could be used by a circuit breaker may be increased beyond what is presently possible given spatial limitations. That is, the cassette-side terminal block 30 and the circuit breaker-side terminal block 50 may each include 2 separate blocks 30a, 30b, 50a and 50b. Here, each separate block 30a, 30b, 50a and 50b may additionally include 3 rows of 13 columns of female and male terminal housings 40 and 60.
Although the embodiments described above are partly characterized by the female terminal housings 40 and the male terminal housings 60 being arrayed on the cassette-side terminal block 30 and the circuit breaker-side terminal block 50, respectively, it is understood that this position could be partly or entirely reversed. Where it is partly reversed, the respective terminal blocks could each support both male and female terminal housings in various combinations and patterns.
While the disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular exemplary embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.
