Patent Application
20160203922
The subject matter disclosed herein relates to circuit breakers and, more particularly to a mounting assembly for mounting a circuit breaker mechanism to a base.
Circuit breakers are used to protect equipment from overcurrent situations caused, for example, by short circuits or ground faults in or near such equipment. A circuit breaker may be manually switched from an “ON” condition to an “OFF” condition and vice versa. Additionally, the circuit breaker includes a mechanism that is configured to automatically switch the circuit breaker to an “OFF” (e.g., “TRIP”) position in response to an undesirable operating situation, such as a short circuit, for example.
The mechanism is mounted to a base of the circuit breaker typically in one of two manners. First, the mechanism may be mounted directly to the base at a position close to several “live” components of the circuit breaker that are located on or within the base. Second, the mechanism may be isolated from the “live” components by mounting the mechanism on an outer surface of a mid-cover that is coupled to the base. Isolating the mechanism is desirable, but such a mounting configuration requires several intermediate mounting components to electrically connect the mechanism to the base. Any system employing a number of components attached to each other will exhibit tolerance stack-up. Reducing the effect of undesirable tolerance stack up is generally effected through more precise manufacturing processes. Therefore, achieving the benefit of isolation associated with mounting on the outer surface of a mid-cover is tempered by increased manufacturing challenges and cost.
According to one aspect of the invention, a mounting assembly for a circuit breaker mechanism includes a base and a mid-cover disposed adjacent the base. Also included is a first pair of mounting posts comprising a first mounting post and a second mounting post extending from the base, the first pair of mounting posts each protruding through the mid-cover. Further included is a first mount hole defined by the first mounting post and a second mount hole defined by the second mounting post. Yet further included is a first pin extending through the first mount hole, the second mount hole and a circuit breaker mechanism frame to retain the circuit breaker mechanism to the base.
According to another aspect of the invention, circuit breaker includes a base and a mid-cover disposed adjacent the base. Also included is at least one mounting post extending from the base and protruding through the mid-cover, the at least one mounting post having an end located at a distal location from the base. Further included is at least one mount hole defined by the at least one mounting post proximate the end of the at least one mounting post. Yet further included is a circuit breaker mechanism frame operatively coupled to a circuit breaker mechanism, the circuit breaker frame defining at least one aperture aligned with the at least one mount hole. Also included is at least one pin extending through the at least one mount hole and the at least one aperture to retain the circuit breaker mechanism to the base.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
Referring to
A base 20 and a mid-cover 22 define a cavity where various circuit breaker components (not shown) are housed, including a line strap to which the mechanism is to be electrically connected. The circuit breaker components within the cavity are “live” components from which the mechanism 12 is to be isolated. To achieve isolation, the mechanism 12 is mounted to an outer surface 24 of the mid-cover 22, as shown. However, isolating the mechanism 12 must also include connecting the mechanism 12 to the base 20, which will be described in detail below.
Referring now to
Each of the mounting posts includes a mount hole defined by the respective mounting post. For example, the first mounting post 28 includes a first mount hole 36, the second mounting post 30 includes a second mount hole 38, the third mounting post 32 includes a third mount hole 40, and the fourth mounting post 34 includes a fourth mount hole 42. In the illustrated embodiment, the mount holes are located proximate an outer end 44 of the respective mounting posts. As will be appreciated from the description herein, the position of the mounting posts, and hence the mount holes, corresponds to positioning of the mechanism 12. In particular, the mount holes are each aligned with respective apertures of the frame assembly 16, which facilitates coupling of the mechanism 12 to the mounting posts of the base 20.
Referring to
Referring again to
The frame assembly 16 also includes a third frame aperture (not shown) defined by the first side frame 18 and a fourth frame aperture (not shown) defined by the second side frame 19. As can be appreciated with reference to the drawings, some of the frame apertures are not visible simply based on their relative positioning with the other components and based on the presence of the pins inserted therein. The third frame aperture and the fourth frame aperture are aligned with each other, as well as with the third mount hole 40 and the fourth mount hole 42. A second pin 60 extends through the third mount hole 40, the third frame aperture, the fourth frame aperture and the fourth mount hole 42 to retain the mechanism 12 to the third mounting post 32 and the fourth mounting post 34.
It is to be appreciated that the first pin 54 and the second pin 60 may extend through other apertures or holes to facilitate retention of the mechanism 12 to the base 20. For example, as shown in the illustrated embodiment, a reset lever 62 is operatively coupled to the mechanism 12 proximate at least one of the frame sides. As shown, the reset lever 62 is coupled to the mechanism 12 at the first side frame 18 proximate the third frame aperture and the third mount hole 40. The reset lever 62 defines at least one reset lever aperture 64 that is aligned with the third mount hole 40, the third frame aperture, the fourth frame aperture and the fourth mount hole 42. Based on the alignment of these features, the second pin 60 extends therethrough. It is to be understood that another reset lever aperture may be disposed on both sides of the third mounting post 32.
In addition to retaining the mechanism 12 to the base 20, one or both of the first pin 54 and the second pin 60 may advantageously provide a retention force between the mid-cover 22 to the base 20. Typically, the mid-cover 22 is retained to the base 20 with a plurality of screws. However, the number of screws required may be reduced with the additional retention force of the first pin 54 and/or the second pin 60. In the illustrated embodiment, the first pin 54 is disposed in close proximity to the outer surface 24 of the mid-cover 22, such that slight movement of the mid-cover 22 results in contact with the first pin 54, which then hinders additional movement of the mid-cover 22. In another embodiment, the first pin 54 is in contact with the outer surface 24 of the mid-cover 22, such that no movement of the mid-cover is permitted.
Advantageously, a mounting assembly for the mechanism 12 is formed by the components described above. The assembly allows for isolation of the mechanism 12 from the “live” components disposed near the bottom end of the base 20, while still providing direct coupling of the mechanism 12 to the base 20 via the mounting posts. The direct mounting reduces tolerance stack-up and other manufacturing issues that add time and cost to the overall design of the circuit breaker 10.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
