Patent Application
20120061219
1. Field
The disclosed and claimed concept relates generally to circuit interruption equipment and, more particularly, to an improved charging handle apparatus for use in a circuit breaker.
2. Related Art
Circuit interruption equipment is generally known for use in interrupting at least a portion of an electrical circuit in certain overcurrent and under-voltage conditions, as well as other conditions. Circuit interruption equipment typically can include a circuit interrupter such as a circuit breaker, and the circuit breaker can be mounted on a switchgear cabinet or other mounting structure, although this is not strictly required. Depending upon the current interruption capability of the circuit breaker, the circuit breaker may include an operating mechanisms having springs that are of a sufficient stiffness that in order to manually recharge them the springs are compressed with a ratcheting type of handle that is mounted to a housing of the circuit breaker and that is manually pivotable to mechanically charge the operating mechanisms. While such system have been generally effective for mechanically charging the operating mechanism of a circuit breaker, such systems have not been without limitation.
Ratcheting handles such as those mentioned above often operate cooperatively with a gear and a shaft to mechanically charge the operating mechanism of the circuit breaker. If the gear is improperly installed with respect to the handle or shaft or both, such as if the gear is installed in a reverse direction from what is correct, the system must be disassembled and the orientation of the gear must be corrected. Moreover, since the gear and the handle cooperate with a shaft, the gear and the handle typically cannot be pre-assembled except when provided in conjunction with an assembled circuit breaker. The inability of the gear to be pre-assembled with the handle can cause the gear to become lost during assembly and can also exacerbate the problem of installing the gear in the correct orientation as mentioned above. It thus would be desirable to provide an improved charging handle apparatus and circuit breaker that meet these and other needs.
These and other needs are met by an improved charging handle apparatus and circuit breaker in accordance with the disclosed and claimed concept. The charging handle apparatus includes a two-piece support apparatus that is disposed on a handle assembly and that is engaged with a gear. More particularly, one of the two pieces of the support apparatus is disposed on the handle assembly, and the other of the two pieces is engaged with the gear and is movable with respect to the first piece. The second piece of the support apparatus includes a number of engagement structures that are engaged with the gear and that retain the gear in a given position with respect to the handle assembly. The charging handle apparatus thus can be provided as a pre-assembled component that is readily mountable to a shaft of a circuit breaker.
Accordingly, an aspect of the disclosed and claimed concept is to provide an improved charging handle apparatus and circuit breaker wherein a gear of the charging handle apparatus cannot be in an improperly installed configuration.
Another aspect of the disclosed and claimed is to provide an improved charging handle apparatus in which the gear can be preassembled to avoid loss and to avoid improper orientation of the gear during installation of the charging handle apparatus into a circuit breaker.
These and other aspects of the disclosed and claimed concept are provided by an improved charging handle apparatus for use in a circuit interrupter to mechanically charge an operating mechanism of the circuit interrupter. The charging handle apparatus can be generally stated as including a handle assembly, a gear structured to be mechanically connected with a portion of the operating mechanism, and a support apparatus disposed on the handle assembly and engaged with the gear. The support apparatus comprises a base portion and an engagement portion. The base portion is disposed on the handle assembly, and the engagement portion is disposed on the base portion and engaged with the gear. At least one of the base portion and the engagement portion is movable with respect to the other of the base portion and the engagement portion.
Other aspects of the disclosed and claimed concept are provided by an improved circuit interrupter, the general nature of which can be stated as including a housing, an operating mechanism disposed on the housing, and the charging handle apparatus as set forth above, the charging handle apparatus being mechanically connected with the operating mechanism to mechanically charge the operating mechanism.
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:
Similar numerals refer to similar parts throughout the specification.
An improved charging handle apparatus 2 in accordance with the disclosed and claimed concept is depicted generally in
The circuit breaker 8 comprises, in a known fashion, a housing 6 upon which are disposed a line conductor 12 and a load conductor 14 that are connected by a set of separable contacts 16. The circuit breaker 8 further comprises an operating mechanism 18 that is disposed on the housing 6 and is operable to separate and connect together the set of separable contacts 16 in certain predefined circumstances. The operating mechanism 18 comprises springs or other structures that are compressed or otherwise mechanically energized by a technician to mechanically charge the operating mechanism 18.
The circuit breaker 8 further comprises the charging handle apparatus 2. The operating mechanism comprises 18 a shaft 10 that mechanically extends between the operating mechanism 18 and the charging handle apparatus 2 to mechanically connect the charging handle apparatus 2 with the operating mechanism 18, and to thereby allow the charging handle apparatus 2 to be operated by a technician to mechanically charge the operating mechanism 18. The charging handle apparatus 2 is disposed in one fashion or another on the housing 6 of the circuit breaker 8 and, in the embodiment depicted herein, is mounted to a plate 78 such as will be discussed below that is disposed on the housing 6.
As can be understood from
The gear 22 comprises a plurality of teeth 46, of which one is a short tooth 46A. Each of the teeth 46 comprises a tooth engagement surface 48. The tooth engagement surfaces 48 are each separately engageable with the pawl engagement surface 38, although it is noted that the tooth engagement surface 48A of the short tooth 46A is configured to not be engageable with the pawl engagement surface 38. The gear 22 has formed generally centrally therein an opening 52 that is non-cylindrical and asymmetrical, and further has formed therein a pair of holes 56A and 56B.
The support apparatus 24 is a two-piece apparatus that comprises a base portion 60 and an engagement portion 62. The base portion 60 is itself disposed on the handle member 26 of the handle assembly 20, and the engagement portion 62 is disposed on the base portion 60 and is engaged with the gear 22. It is noted that the base portion 60 comprises a substantially cylindrical first bearing surface 64, and that the engagement portion 62 comprises a substantially cylindrical second bearing surface 68, with the first and second bearing surfaces 64 and 68 being complementary. That is, the first and second bearing surfaces 64 and 68 are slidably engageable with one another, thus permitting the engagement portion 62 to be movable with respect to the base portion 60, and vice versa. While the first and second bearing surfaces 64 and 68 are depicted as being substantially cylindrical, it is noted that in the depicted embodiment the first and second bearing surfaces 64 and 68 are each formed to have a draft angle that is of about 0.5 degrees and that is of no more than about 1.0 degrees. The draft angles enable the base portion 60 to retain the engagement portion 62 engaged with a face of the gear 22 while still permitting the engagement portion 62 to rotate with respect to the base portion 60. While such draft angles are employed in the embodiment depicted herein, it is noted that they are not required and rather could be absent from other embodiments not expressly depicted herein.
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Advantageously, the engagement portion 62 and the gear 22 are configured to enable at most only one orientation, i.e., the first orientation as mentioned above, in which the engagement structures 76A and 76B are received in the holes 56A and 56B and in which the openings 52 and 72 are aligned with one another. For instance, an exemplary second orientation of the engagement portion 62 and the gear 22 is depicted generally in
It also can be understood that the engagement structures 76A and 76B received in the holes 56A and 56B, respectively, retain the gear 22 between the engagement surface 74 of the engagement portion 62 and an opposite interior surface of the handle member 26. As such, the charging handle apparatus 2 can be provided as a pre-assembled component which can then be mounted to the shaft 10 of the circuit breaker 8 without any meaningful concern that the gear 22 could be mis-oriented in the fully assembled circuit breaker 8. Such retention of the gear 22 between the support apparatus 24 and the handle member 26 of the handle assembly 20 also resists loss of the gear 22 during assembly of the charging handle apparatus 2 onto the shaft 10, all of which saves time and effort.
While specific embodiments of the invention 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 invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.
