Patent Application
20080174399
1. Field of the Invention
This invention relates generally to fuses and, more particularly, to an outdoor fuse mounting assembly.
2. Background Information
A fuse is a type of overcurrent protection device for installation into a power circuit. A fuse has an element (or a plurality of elements), which is typically a metal wire or conductive strip or other conductor, which will melt, sever, or otherwise open when heated by a predetermined electrical current for a predetermined time. Accordingly, fuses are generally designed to allow the flow of an electrical current up to a certain current-time threshold. Once the current-time threshold is crossed, the element in the fuse opens, thereby protecting the power circuit from the overcurrent condition.
Fuses can be installed in a variety of environments. For example, a fuse can be installed into a power circuit that is located outdoors or, alternatively, the fuse can be installed into a power circuit that is located indoors. A fuse that is installed into an outdoor power circuit is typically mounted onto a mounting assembly which is made from a ceramic material. A ceramic mounting assembly, however, has a number of shortcomings. For instance, an outdoor ceramic mounting assembly is typically exposed to a variety of environmental conditions, such as inclement weather, which can damage (e.g., crack) the ceramic mounting assembly. Moreover, an outdoor ceramic mounting assembly can be damaged during transit to the installation site thereby rendering the outdoor ceramic mounting assembly useless.
Various needs are met by various embodiments of the invention which provides a fuse mounting assembly comprising at least one epoxy-bonded glass-fiber core that is surrounded by at least one resilient sleeve which has a number of radially extending members.
In accordance with one embodiment of the invention, a fuse mounting assembly comprises a first core and a second core. Each of the first and second cores have a first end, a second end, and an outer perimeter. First and second mounting brackets are connected to the first end of the first core and the second end of the second core, respectively, while a third mounting bracket is disposed between the second end of the first core and the first end of the second core. A resilient sleeve having a number of radially extending members is disposed around the outer perimeter of the first core while another resilient sleeve having a number of radially extending members is disposed around the outer perimeter of the second core.
In accordance with another embodiment of the invention, a fuse mounting assembly comprises a core having a first end, a second end, and an outer perimeter. A mounting bracket is connected to the first end of the core, and another mounting bracket is connected to the second end of the core. A resilient sleeve having a number of radially extending members is disposed around the outer perimeter of the core.
In accordance with yet another embodiment of the invention, a fuse mounting assembly comprises a first core and a second core. Each of the first and second cores has a first end, a second end, and an outer perimeter. First and second mounting brackets are connected to the first end of the first core and the second end of the second core, respectively, while a third mounting bracket is disposed between the second end of the first core and the first end of the second core. A resilient sleeve having a number of radially extending members is disposed around the outer perimeter of the first core while another resilient sleeve having a number of radially extending members is disposed around the outer perimeter of the second core. A fuse is connected to each of the first and second mounting brackets.
In accordance with yet another embodiment of the invention, a fuse mounting assembly comprises a core having a first end, a second end, and an outer perimeter. A mounting bracket is connected to the first end of the core, and another mounting bracket is connected to the second end of the core. A number of individual discs are disposed around the outer perimeter of the core.
A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
As employed herein, the term “number” means one or an integer greater than one (i.e., a plurality).
As employed herein, the term “mechanical fastener” or variations thereof shall refer broadly to any suitable fastening, connecting or tightening mechanism including, but not limited to, screws, bolts, and the combination of bolts and nuts.
As employed herein, the term “ceramic” or variations thereof shall refer broadly to an inorganic insulative material or a non-metallic insulative material.
As employed herein, the term “silicone” or variations thereof shall refer broadly to a polymer which has a backbone structure of silicon-oxygen or some other silicon based polymer that can be used for electrical insulation purposes. For example, without limitation, the silicone can be silicone rubber.
As employed herein, the term “medium voltage fuse” or variations thereof shall refer to a fuse suitable for use in a power circuit having a voltage ranging from about 1.0 kilovolts to about 69.0 kilovolts.
As employed herein, the term “electrical creepage” or variations thereof shall refer to the shortest distance along a continous insulating surface between two conducting bodies that would normally be at different electrical potentials.
When referring to any numerical range of values, such ranges are understood to include each and every number and/or fraction between the stated range minimum and maximum.
Directional phrases used herein, such as, for example, upper, lower, left, right, vertical, horizontal, top, bottom, above, beneath, clockwise, counterclockwise and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.
As stated above, one shortcoming of a ceramic fuse mounting assembly is that the ceramic fuse mounting assembly can be damaged (e.g., cracked) by inclement weather or improper handling during transport to an installation site. Accordingly, there is a need for a fuse mounting assembly that is not only resistant to environmental conditions, but is resistant to conditions that can arise during transport as well.
These needs, and others, are met by various embodiments of the invention which provide a fuse mounting assembly for use with a fuse, such as a medium voltage fuse, which comprises at least one epoxy-bonded glass-fiber core that is surrounded by at least one resilient sleeve which has a number of radially extending members.
Referring to
Continuing with
Disposed at the first end 8 of the first core 4 is a first mounting bracket 24 that is secured to the first core 4 by a mechanical fastener 26 and a washer 28. Disposed at the second end 16 of the second core 6 is a second mounting bracket 30 that is secured to the second core 6 by a mechanical fastener 32 and a washer 34. The first and second mounting brackets 24,30 are adapted to connect with first and second fuse mounting members 36,38, respectively, which are adapted to receive a fuse 40 (see
Referring to
For clarity, hereinafter, the radially extending members 44,48 and the individual discs 52 shall be collectively referred to as discs 50.
In general, the discs 50 each have a diameter that is larger than the diameter of each of the first and second cores 42. However, despite
When a force is applied to a disc 50, the disc 50 is able to flex thereby absorbing the force. Accordingly, the discs 50 are able to absorb a force that would otherwise damage a ceramic fuse mounting assembly during transit to an installation site. Once the force has dissipated, the discs 50 will return to their original configuration (shape). Due to the resilient nature of the discs 50, the disclosed fuse mounting assembly 2 will, typically, not be damaged if the fuse mounting assembly 2 is jostled during transport. Moreover, the discs 50 also provides a degree of protection for the first and second cores 4,6 in the event that a random object might strike the first and second cores 4,6. In addition to having the ability to absorb various forces which the fuse mounting assembly 2 might encounter, the discs 50 also increases the electrical creepage distance of the fuse mounting assembly 2 thereby preventing electricity from traveling along the surface of the fuse mounting assembly 2. Yet another advantage that is provided by the discs 50 is that the shape of the discs 50 is conducive to inhibiting water from remaining (pooling) on a surface of the disc 50. One advantage that is derived from preventing water, such as contaminated water (e.g., water that is contaminated with salt and/or some type of industrial contaminant), from pooling on the surface of the disc 50 is that it preserves the electrical insulating capabilities of the disc 50 from the high electrical conductivity of the contaminated water.
In another embodiment of the invention, the first and second cores 4,6 may be replaced with a single core that is manufactured from an epoxy-bonded glass-fiber material or a ceramic material. Disposed around the outer perimeter of the single core could either be a single resilient sleeve, which has a number of radially extending members, or a number of individual discs 52. For example, a single resilient sleeve with eighteen radially extending members could be disposed around the outer perimeter of the single core. Alternatively, eighteen individual discs 52 could be disposed around the outer perimeter of the single core as well. It should be noted, however, that any suitable number of discs 50 could be disposed around the outer perimeter of the single core. In one embodiment, a third mounting bracket 20 is disposed around the outer perimeter of the single core.
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 the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.
