U.S. patent application number 16/798320 was filed with the patent office on 2020-09-10 for 7-way crab joint.
The applicant listed for this patent is Richards Manufacturing Company, LP. Invention is credited to Bruce Bier, Jeffrey L. Madden.
Application Number | 20200287364 16/798320 |
Document ID | / |
Family ID | 1000004853358 |
Filed Date | 2020-09-10 |
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United States Patent
Application |
20200287364 |
Kind Code |
A1 |
Bier; Bruce ; et
al. |
September 10, 2020 |
7-Way Crab Joint
Abstract
An apparatus and method for interconnecting mains cables used
for underground secondary low-voltage AC network systems utilizing
an improved crab joint connector arranged to maximize the number of
interconnections in a compact design wherein the plurality of legs
are arranged in a rectangle configuration and a single bus leg is
positioned at an end of an insulated housing.
Inventors: |
Bier; Bruce; (Warren,
NJ) ; Madden; Jeffrey L.; (Bernardsville,
NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Richards Manufacturing Company, LP |
Irvington |
NJ |
US |
|
|
Family ID: |
1000004853358 |
Appl. No.: |
16/798320 |
Filed: |
February 22, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14727825 |
Jun 1, 2015 |
10574041 |
|
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16798320 |
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13744337 |
Jan 17, 2013 |
9048638 |
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14727825 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02G 3/263 20130101;
Y10T 29/49195 20150115; Y10T 29/49197 20150115; H02G 15/113
20130101; H02G 5/00 20130101; H02G 1/14 20130101 |
International
Class: |
H02G 1/14 20060101
H02G001/14; H02G 5/00 20060101 H02G005/00; H02G 15/113 20060101
H02G015/113 |
Claims
1. A method of establishing an electrical connection comprising the
steps of: connecting a plurality of cable mains in a rectangular
configuration to a cable joint assembly; and connecting a bus
connection to a non-limitered bus connector of the cable joint
assembly at a location substantially adjacent to and substantially
external of the rectangular configuration and at a location
substantially along a centerline of the rectangular configuration.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/727,825, filed on Jun. 1, 2015, now U.S.
Pat. No. 10,574,041, which is a continuation of U.S. patent
application Ser. No. 13/744,337, filed on Jan. 17, 2013, now U.S.
Pat. No. 9,048,638, issued Jun. 2, 2015, and the foregoing
applications are herein incorporated by reference in their
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus for
interconnecting mains cables used for underground secondary
low-voltage AC network systems. More particularly, the invention
relates to an improved crab joint connector arranged to maximize
the number of interconnections in a compact design.
BACKGROUND OF THE INVENTION
[0003] Electrical distribution networks are critical for the
delivery of electricity to consumers and businesses from the
transmission system. Such a network can include power lines,
substations, transformers, and meters that are interconnected by
thousands of miles of cables. In densely populated urban areas,
electricity is transmitted to consumers via secondary low-voltage
AC network systems which are formed by feeding several transformers
into a common bus. A secondary low-voltage AC network system is
generally characterized as a system wherein customers are served
from three-phase, four-wire low-voltage circuits supplied by two or
more network transformers whose low-voltage terminals are connected
to the low-voltage circuits through network protectors. The
secondary network system has two or more high-voltage primary
feeders, with each primary feeder typically supplying 1-30 network
transformers, depending on network size and design. Such systems
include automatic protective devices intended to isolate faulted
primary feeders, network transformers, or low-voltage cable
sections while maintaining service to the customers served from the
low-voltage circuits. While secondary low-voltage AC network
distribution connections as discussed herein are typically housed
in an above-ground cabinet or a below-ground box, it is generally
preferred that these secondary networks are located underground,
due to the impracticability of using overhead wires in densely
populated urban areas. As a result, the connections may be
subjected to moisture and may even become submerged in water. If
the cable conductors or conductor members of the bus bars are left
exposed, water and environmental contaminants may cause short
circuit failure and/or corrosion thereon. In addition, as an urban
area grows, the process of connecting additional customers to the
secondary network involves the costly procedure of excavating and
splicing connections to the common bus. Such problems of expansion
have not been entirely ignored by the industry.
[0004] It is believed that since about 1935, crab joints have been
used for reducing the time associated with interconnecting mains
cables used in underground secondary low-voltage AC network
systems. A crab joint basically includes a central hub (often
referred to as a "busbar") with multiple fusible connections
(referred to as "limiters") to a number of cables constituting part
of a network. The limiters act to protect the cables connected to
the crab joint in case of a failure of any of the cables in the
network. A typical crab joint consists of a plurality of cable
connectors, also known as legs, electrically connected to a common
junction plate. The connectors are arranged such that a plurality
of legs surround a center leg as shown in FIG. 1A (PRIOR ART). The
center member is connected to other electrical components, such as
another crab joint, while the surrounding legs are connected to a
continuation of the cables for "network mains" or feeding
customers. More specifically, FIG. 1A depicts the typical
arrangement wherein a center connector 100 is surrounded by a
plurality of connectors 102. Connector 102 is typically a fusible
connector, while connector 100 is non-fusible and connected to
other accessories, such as another crab joint. The crab joint
greatly reduces the labor associated with splicing cables and
improves reliability because the linesperson simply connects a
prepared cable to an available connector, instead of preparing
multiple cables for splicing. This achieves the requirement to
connect a number of cables to one geometric point (in electrical
terms).
[0005] The conventional crab joint generally used in secondary
low-voltage AC network systems comprises compression connectors
with EPDM rubber seals to connect network cables to the busbar. In
older prior art joints, the limiter elements could not be
individually replaced and in early conventional crab joint design,
a failed or blown limiter was not readily discernible from the
exterior of the crab joint. Of course, such construction made it
very difficult to visually detect an opened limiter in a crab
joint. As a result, opened limiters often existed undetected for
long durations resulting in low voltage in the serviced area or
overloading of a network transformer. Repairs of such problems
required excessive work by "troubleshooting crews" tasked with
testing and inspecting substantial lengths of cable runs and
related components without an easy solution for troubleshooting
failure.
[0006] While there have been several improvements to the crab
joint, such as material improvements, fault identifiers, and the
like, the arrangement of the connectors has remained largely
unchanged since the original development of crab joints over
seventy years ago. One major development in the field of secondary
voltage systems was the introduction of fusible connectors;
however, crab joint configuration design still generally remained
the same. Fusible connectors were designed in response to one or
more mains in a crab joint experiencing excessive currents due to a
short circuit. The short circuit fault caused the connector of a
crab joint to overheat and eventually destroy itself. This
destruction could subsequently damage the surrounding connectors
and mains cables that may not have been experiencing the fault
current. As a result, a short circuit fault could bring down power
to all customers connected to the crab joint. A limiter, such as a
fuse, is typically located between the mains connection and
junction plate--where all the mains connectors are electrically
connected together. The limiter is designed to disconnect the main
experiencing the fault condition, just before the heat from the
short circuit current damages the other mains connected to the crab
joint.
[0007] One primary reason that crab joint design has not departed
from the original design conceived over seventy years ago is that
current crab joint designs simply work for the intended purpose. As
referenced, even with the addition of the fusible connectors, crab
joints have been modestly modified and maintained the same
arrangement for the connectors. In fact, the addition of these
limiters has reinforced the existence of the current design, as the
minimum distance between connectors must be such that it impedes a
blown limiter from damaging other connectors. Thus, rather than
minimizing the distance between crab joint connectors, a current
trend of crab joint designs focuses on improving fusible connectors
to exist in the environment of existing crab joints. For example,
Mofatt U.S. Pat. No. 7,358,845 entitled "Cable Limiter and Crab
Limiter Employing Replaceable Fusible Element" is directed to the
improved fusible connectors and references various other inventions
relating to improving fuses which are designed to be compatible
with crab joint systems. FIG. 13 depicts a crab joint known in the
art which is integral to the operation of the improved design of
fusible connectors of Mofatt. As shown, the connectors are arranged
similar such that a center connector 104 is surrounded between a
plurality of connectors 106. It is readily apparent in the Moffat
disclosure that the crab joints known in the art are of the typical
design disclosed in FIG. 1A wherein the ring bus leg is disposed in
the center of the arrangement. In the Mofatt design, when a fusible
connector fails, only the failed fuse needs to be replaced instead
of the whole crab joint. While Mofatt teaches the inclusion of an
annunciator on the fusible connector to indicate the status of the
fusible element (wherein the annunciator can either be an auditory
signal or wireless communication in order to facilitate personnel
in finding and replacing blown fuses), the invention of Mofatt is
designed to be compatible with the connectors in the traditional
crab joint formation currently known in the art.
[0008] Even when inventions in the field of crab joints result in
the adjustment of the configuration of crab joints, the change is
minimal and is generally for purposes other than compactness. In
one example of modified crab joint design (U.S. Pat. No. 8,129,618
entitled "Cable Joint," issued to Bier), the location of the center
connector is offset. According to the patent, this modification was
primarily to facilitate a U-shape which was designed to allow
personnel to easily view and visually identify a blown fuse without
having to move the location of connected components. This modified
design is shown in FIG. 1C (PRIOR ART). Specifically FIG. 1C
depicts a preferred embodiment of Bier, which teaches a seven way
crab joint with an improved design including a visual indicator for
determining whether or not a corresponding limiter is blown. Center
connector 108 is positioned between a plurality of connectors 110,
but is offset from a central position of the crab joint. As
mentioned, the purpose of the change of the location of the center
connector was to facilitate personnel easily looking down and
identifying a blown fuse, rather than for the purpose of providing
a compact design which eliminates material and space requirements
when in use.
[0009] While FIG. 1C discloses the improved seven-way crab joint of
Bier U.S. Pat. No. 8,129,618 entitled "Cable Joint," a simpler
seven-way design is presented in FIG. 1D. Specifically, FIG. 1D
illustrates an arrangement that adapts the arrangement in FIG. 1A,
but for a seven way crab joint. Similar to the arrangement in FIG.
1A, a center connector 112 is surrounded by connectors 114.
[0010] It is well known in the art that space allocation in
electrical component cabinets and underground systems is a primary
concern, especially as more power is necessary to support
residential and commercial areas in growing metropolitan cities.
The facilities for the components of secondary low-voltage AC
network systems is generally not expanding in proportion to the
demand, and as a result, the components themselves need to change.
Thus, there is an apparent need in the art for components of
reduced size. However, merely altering the size of the components
is not always an easy solution. In particular, crab joints must be
designed of sufficient size, shape, and material so that the crab
joint can handle the substantial voltage without significantly
impeding current flow, can be easily repaired, can be compatible
with existing systems, and most importantly can handle surges and
potential damage from blown fuses. So while there exists an
apparent need for a compact crab joint design, no known
developments have resulted in an improved design that meets the
objectives required to operate in the complex environment of
secondary low-voltage AC network systems.
SUMMARY
[0011] Various embodiments of the present invention involve a
compact crab joint connector. In the preferred embodiment, the crab
joint connector is a seven-way crab joint connector. The crab joint
of the present invention is directed to a multiple cable connection
wherein the mains cables are, through the use of the crab joint,
electrically interconnected and may be joined to auxiliary or
service cables, and wherein each connection of a cable terminal
through the joint is separably and independently protected by a
limiter section. The primary object of the present invention is to
allow for the plurality of cables to be electrically connected
through the use of a single unitary element with at least some of
the cable lengths protected within the unitary element by a limiter
or fuse component in a substantially reduced space. In the event
that a fault develops in one or more of the connected cables, the
limiter or fuse component will blow and open the cable circuit
thereby interrupting the flow of the electrical current before the
faulted circuit is allowed to create substantial damage to the
respective cable insulation. Of primary concern is that the crab
joint is designed so that a single short in one of the cables does
not cause substantial damage to the other connected cables. One of
ordinary skill in the art will readily recognize that it is of
utmost importance that the crab joint of the present invention is
designed so that any fault in the cables connected to the unitary
joint does not result in the interruption of the electrical
continuity of the serviced facility for the crab joint.
[0012] The development of a compact crab joint is necessary in the
art for a myriad of reasons. First, the compact crab joint of the
present invention is designed to reduce the time necessary for
installation or maintenance. This benefit over existing joints is
the result of the compact design as less material is required to be
excavated to install a new crab joint in an underground environment
and less space is required in an aboveground installation.
Furthermore, in pre-existing underground structures, a compact crab
joint allows more crab joints to be installed before requiring the
costly construction of an enlarged structure. While the space
limitation is the primary benefit of the compact crab joint of the
present invention (primarily as a result of the repositioning of
the ring bus leg), the present invention also allows for improved
operation and maintenance as the ring bus leg is better located in
the rear of the joint allowing unobstructed access to limiter
legs.
[0013] It is an object of the present invention to provide a crab
joint capable for use in a secondary low-voltage AC network system.
In one embodiment of the present invention, a crab joint is
disclosed including an insulated housing with a plurality of
integrally molded legs. In the present example, the crab joint has
a plurality of legs extending from a first end of the housing and a
plurality of legs extending from a second end of the housing. A
pigtail (short cable length) is attached to each leg wherein the
pigtail allows a linesperson to easily attach a cable-to-cable butt
splice to the crab joint. The legs extending from the joint are
electrically connected at a junction plate located in an
intermediate section of the housing, and a limiter, known in the
art, is positioned between the leg and the junction plate. At least
one ring bus leg is included on each end of the housing for the
purpose of connecting to another electrical apparatus, such as
another crab joint. The ring bus leg is electrically connected to
the junction plate, and a pigtail is also attached to the ring bus
leg in order to improve the ease of installing a prepared cable to
the crab joint.
BRIEF DESCRIPTION OF THE FIGURES
[0014] A further understanding of the present invention and the
objectives other than those set forth above can be obtained by
reference to the various implementations set forth in the
illustrations of the accompanying figures. Although the illustrated
implementations illustrate certain aspects of the present
invention, the apparatus and method of use of the invention, in
general, together with further objectives and advantages thereof,
may be more easily understood by reference to the drawings,
examples, and the following description. The examples and figures
are not intended to limit the scope of this invention, which is set
forth with particularity in the claims as appended or as
subsequently amended, but merely to clarify and exemplify the
invention. The detailed description makes reference to the
accompanying figures wherein:
[0015] FIG. 1A (PRIOR ART), 1B (PRIOR ART), 1C (PRIOR ART), and 1D
(PRIOR ART) depict typical arrangements of crab joint
connectors.
[0016] FIG. 2 is a perspective view of an exemplary seven-way crab
joint of the present invention.
[0017] FIG. 3 is a perspective view of the preferred embodiment of
the present invention depicting an exemplary seven-way crab
joint.
[0018] FIG. 4 is a side view of the crab joint installation of the
preferred embodiment of an exemplary seven-way crab joint of FIG.
2, composed of a series of racked crab joints 200.
[0019] FIG. 5 is a side view of the preferred embodiment of the
present invention depicting an exemplary seven-way crab joint.
[0020] FIG. 6 is a top view of the preferred embodiment of the
present invention depicting an exemplary seven-way crab joint.
[0021] FIG. 7 is a front view of the crab joint installation of the
preferred embodiment of the present invention depicting an
exemplary seven-way crab joint in a vertical racked environment,
comprising a series of racked crab joints as generally depicted in
FIG. 2.
[0022] FIG. 8A and FIG. 8B are cut-away views of the various
components utilized to construct an existing crab joint (FIG. 8A)
and the low-profile crab joint (FIG. 8B) claimed in the present
invention.
[0023] FIG. 9A and FIG. 9B are side views of an existing crab joint
(FIG. 9A) and the low-profile crab joint (FIG. 8B) claimed in the
present invention.
[0024] FIG. 10A and FIG. 10B are side views of an existing crab
joint (FIG. 10A) and the low-profile crab joint (FIG. 10B) claimed
in the present invention in a racked environment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] A detailed description of the various embodiments of the
present invention is disclosed herein. However, techniques of
manufacture and resulting structures in accordance with the present
invention may be embodied in a wide variety of forms and modes,
some of which may be quite different from those in the disclosed
embodiments. Consequently, the specific structural details
disclosed herein are merely representative, yet in that regard,
they are deemed to represent suitable implementations for purposes
of disclosure and to provide a basis for the claims herein, which
define the scope of the present invention. Well known methods,
procedures, and substances for both carrying out the objectives of
the present invention and illustrating the preferred embodiment are
incorporated herein but have not been described in detail as to not
unnecessarily obscure novel aspects of the present invention.
[0026] Unless the context clearly requires otherwise, throughout
the description and the claims, the words "comprise," "comprising,"
and the like are to be construed in an inclusive sense, as opposed
to an exclusive or exhaustive sense; that is to say, in the sense
of "including, but not limited to." As used herein, the terms
"connected," "coupled," or any variant thereof, means any
connection or coupling, either direct or indirect, electronic or
otherwise, between two or more elements; the coupling or connection
between the elements can be physical, logical, or a combination
thereof. Additionally, the words "herein," "above," "below," and
words of similar import, when used in this application, shall refer
to this application as a whole and not to any particular portions
of this application. Where the context permits, words in the
Detailed Description of the Preferred Embodiment using the singular
or plural number may also include the plural or singular number
respectively. The word "or," in reference to a list of two or more
items, covers all of the following interpretations of the word: any
of the items in the list, all of the items in the list, and any
combination of the items in the list.
[0027] In accordance with an exemplary embodiment of the present
invention as shown in FIG. 2 through FIG. 5, a crab joint
installation 214 is composed of a series of racked crab joints 200
placed in a vertical arrangement. The crab joint installation 214
is depicted in a common rack system 216 which is generally utilized
in an underground installation. As depicted in the crab joint
installation 214, three seven-way crab joints 200 are shown allowed
for the installation of a total of six ring bus legs and eighteen
standard legs. The insulated housing 202 is shown with a plurality
of integrally molded legs 210. In the present example, crab joint
200 has six legs 210 extending from a first end 204 of housing 202
and six legs 210 extending from a second end 206 of housing 200.
While a seven-way design is depicted (i.e., six legs and one ring
bus leg), one of ordinary skill in the art will readily recognize
that the same design structure could be employed for a three-way
design by eliminating four outermost legs and a five-way design by
eliminating two outermost legs. A pigtail 211 is attached to each
leg 210. Pigtail 211 allows a linesperson to easily attach a
cable-to-cable butt splice to crab joint 200. The legs 210
extending from end 206 and end 204 are electrically connected at a
junction plate (not shown) located in intermediate section 208 of
housing 200. A limiter, known in the art, is positioned between leg
210 and the junction plate. Each pigtail 211 is rated for a current
that does not exceed the current rating of the limiter connecting
leg 210 to the junction plate, during normal operation. Further, at
least one bus leg 212 is included on each end of housing 202, for
the purpose of connecting to another electrical apparatus, such as
another crab joint. Ring bus leg 212 is electrically connected to
the junction plate (not shown) located in intermediate section 208
of housing 202. A ring bus leg as used throughout this application
is generally defined as a non-limitered (i.e., non-fused) connector
having a cable to create an electrical reference point that is
designed to balance the load on a particular joint. A pigtail 211
is also attached to ring bus leg 212 in order to improve the ease
of installing a prepared cable to crab joint 200.
[0028] The junction plate (not shown), legs 202, and ring bus leg
212 can be made from a highly conductive material, such as pure
copper, and plated with a material such as tin to resist
corrosion.
[0029] In the present embodiment, insulated housing 202 consists of
an inner high-temperature shell, which provides separate arcing
chambers for each leg 210. Therefore, the arching chambers of
insulated housing 210 confine the resultant electrical arcs and
molten material incident from a blown limiter. Additionally, the
outer surface of insulated housing 202 can be made of various
insulating polymers, silicone, EPDM or other suitable materials
known to those of ordinary skill in the art. The insulation surface
of pigtails 211 can also be made of the same materials as that of
insulated housing 202.
[0030] FIG. 3 is a perspective view of an end of the improved crab
joint 200 the present invention. Compared to prior art crab joints
referenced herein, such as the embodiment presented in FIG. 13
(PRIOR ART), the arrangement of the present invention reduces the
space requirement of a crab joint as indicated by the dash lined
300. This is accomplished by changing the position of ring bus leg
212 from a central position to a position that optimizes vertical
space. In the present invention, the plurality of legs 210 are
arranged in a rectangular configuration. Ring bus leg 212 is
positioned at a side of insulated housing 202, in this case, the
side located nearest to the rack installation once racked. This
positioning of the crab joints 200 is further shown in FIG. 4.
Specifically, FIG. 4 shows a side view of the crab joint
installation 214 of FIG. 2, composed of a series of racked crab
joints 200. In the present figure, the ring bus leg 212 for each
crab joint 200 is shown positioned between the common rack system
216 and the plurality of legs 210. Common rack system shelf 402 is
also shown for supporting the crab joints 200 and maintaining the
distance between each in a vertical plane.
[0031] Next, FIG. 5 is a side view of an exemplary seven-way crab
joint of the present invention with assembled cable mains and a
ring bus leg connected thereto. In the present embodiment the
position of legs 210 are staggered. The insulated housing 202 is
shown with a plurality of integrally molded legs 210. In this
depiction, the crab joint has six legs 210 extending from a first
end 204 of insulated housing 202 and six legs 210 extending from a
second end 206 of housing 200. A pigtail 211 is attached to each
leg 210. The legs 210 extending are electrically connected at a
junction plate (not shown) located in intermediate section 208 of
insulated housing 200. Again, the space-saving improvements are
depicted by the dashed line 300.
[0032] FIG. 6 depicts a top view of an exemplary embodiment of the
present invention, further exemplifying the staggered positioning
of legs 210. Again, the insulated housing 202 is shown with a
plurality of integrally molded legs 210. In this depiction, crab
joint 200 has six legs 210 extending from a first end 204 of
insulated housing 202 and six legs 210 extending from a second end
206 of housing 200. A pigtail 211 is attached to each leg 210. The
legs 210 extending are electrically connected at a junction plate
(not shown) located in intermediate section 208 of housing 200.
Ring bus leg 212 is positioned at the side of crab joint 200 which
is designed to be positioned closest to a rack structure (not
shown) in a mounted assembly.
[0033] Turning next to FIG. 7, depicted is a front view of the a
crab joint installation 214, composed of a series of racked crab
joints 200 placed in a vertical arrangement as generally depicted
in FIG. 2. The crab joint installation 214 is depicted in a common
rack system 216 which is generally utilized in an underground
installation. The intermediate section 208 of the crab joint 200
rests on and can be secured to shelf 402 of the common rack system.
Shelf 402 can be positioned to accommodate the reduced size of crab
joint 200. Three seven-way crab joints 200 are shown allowing for
the installation of a plurality of ring bus legs and standard legs.
Pigtails 211 are further shown attached to the various legs. Due to
the compact configuration of crab joints 200, rack space is
optimized in the vertical direction allowing for the inclusion of
multiple additional crab joints in a space reserved for far fewer
prior art crab joints.
[0034] FIG. 8A and FIG. 8B are designed to visually depict the
improvement over the existing art by providing a cut-away view of
the various components utilized to construct an existing crab joint
(FIG. 8A) and the low-profile crab joint (FIG. 8B) claimed in the
present invention. The insulating housing of the existing crab
joint 800 (FIG. 8A) is comprised of a top portion 802, bottom
portion 804, left portion 806 composed of two units, and a right
portion 808 composed of two units. Each of the aforementioned
components of the insulating housing is designed to secure the
junction plate 810 therewithin in the intermediate assembly of the
constructed insulation housing. As previously mentioned, the
junction plate 810 is made from a highly conductive material, such
as pure copper, and plated with a material such as tin to resist
corrosion, and is designed to serve as a conduction and connection
point for the plurality of standard legs 812. In addition, the ring
bus leg 814 is electronically connected to the junction plate 810
at a position central to the standard leg assembly. While the
improved crab joint 820 of the present invention, as depicted in
FIG. 8B, accomplishes the same objectives of the known crab joint
800 depicted in FIG. 8B, the improvements in the positioning of the
legs and construction of the insulated housing results in a design
which is clearly more compact and utilizes less material in its
construction than known designs. Comparing FIG. 8A and FIG. 8B,
which are presented roughly to scale to each other, one of ordinary
skill in the art will readily recognize that by removing the bus
leg 834 from the central portion of the junction plate 830 (and
making other modifications as disclosed in more detail herein), an
improved design is achieved which departs significantly from
designs known in the art. Like the known crab joint 800 depicted in
FIG. 8A, the low profile crab joint 820 of the present invention as
depicted in FIG. 8B includes an insulating housing comprised of a
top portion 822, bottom portion 824, left portion 826, and a right
portion 828. While the prior art crab joint must utilize two units
to form the left portion and two units to form the right portion to
allow for the legs to be secured therewithin, the design of the
present invention accomplishes the same objective by utilizing a
single unit for each portion (or in some instances a single unit
fused from one or more units). This is a significant improvement
over the existing art as it results in the use of less material for
the manufacture and of course reduces the manufacturing
requirements by limiting the number of portions which must be
manufactured. Further, while each design depicted in FIG. 8A and
FIG. 8B includes the same number of standard legs 812 (FIG. 8A),
832 (FIG. 8B), the connection elements of standard legs 832, are
designed at an angle departing from vertical so as to allow for a
more compact position of the outer legs. Such positioning of the
connection elements further facilitates the compact design of the
present invention.
[0035] The improvements discussed in the present detailed
description, including those addressed in the comparison of FIG. 8A
in light of FIG. 8B, are further evident in FIG. 9A and FIG. 9B. By
removing the ring bus leg 902 (FIG. 9A) from the central position
to the position of ring bus leg 912 (FIG. 9B), the overall vertical
dimension of known crab joint 900 is substantially reduced as
evidenced in the crab joint 910 of the present invention. In one
exemplary embodiment of the present invention, this repositioning
of the ring bus legs (along with the other improvements disclosed
herein with respect to the present design) results in over a thirty
percent reduction in the overall dimension. Specifically, in one
known exemplary embodiment, the overall vertical dimension of the
crab joint is 5.875 inches, and in an exemplary embodiment of the
improved design of the crab joint, the overall vertical dimension
is less than 4.066 inches. It is also evident in the figures that
such positioning of the ring bus leg 902 (FIG. 9A) at a central
position in the known crab joint 900 to the positioning of the ring
bus leg 912 (FIG. 9B) at an outer position in the improved crab
joint also allows for the reduction of insulating material within
the insulating housing 904 (FIG. 9A) as compared to the insulating
housing 914 (FIG. 9B) and further allows for closer positioning of
the standard legs 906 (FIG. 9A) of the known crab joint 900 and the
standard legs 916 (FIG. 9B) of the improved crab joint 910 of the
present invention.
[0036] The compact nature and improvements of the present invention
are most apparent in FIG. 10A as compared to FIG. 10B which depicts
known crab joints 1000 (FIG. 10A) in a racked environment as
compared to the improved crab joints 1010 (FIG. 10B) in a racked
environment. Like several of the prior figures, FIG. 10A and FIG.
10B are show in relevant scale to each other. Substantial vertical
height reduction is achieved, in one exemplary embodiment by
approximately thirty percent, by repositioning the ring bus leg
1002 (FIG. 10A) of known crab joints 1000 (FIG. 10A) from a central
position to the position of ring bus leg 1012 (FIG. 10B) of
improved crab joints 1010 (FIG. 10B) to a rack-side position and
making the other improvements as disclosed herein. One of ordinary
skill in the art will readily recognize that such improvements, at
least in this particular example, result in the ability to include
a fourth crab joint in the space previously occupied by only three
crab joints.
[0037] Thus, there has been summarized and outlined, generally in
broad form, a plurality of the most important features of the
present invention. While this summary is presented so that the
novelty of the present contribution to the related art may be
better appreciated, it will further be apparent that additional
features of the invention described hereinafter (which will form
the subject matter of the claims appended hereto) will further
define the scope, novelty, and in certain instances the
improvements upon any existing art. The following description
provides specific details for a thorough understanding of, and
enabling description for, various examples of the technology. One
skilled in the art will understand that the technology may be
practiced without many of these details and it is to be readily
understood that the invention presented herein is not limited in
its application to the details of construction, namely the seven
leg configuration, and to the arrangements of the components set
forth in the foregoing description or illustrated in the various
figures integrated and categorized herein. For example, in some
instances, well-known structures and functions have not been shown
or described in detail to avoid unnecessarily obscuring the
description of the examples of the technology. It is intended that
the terminology used in the description presented below be
interpreted in its broadest reasonable manner, even though it is
being used in conjunction with a detailed description of certain
examples of the technology. Although certain terms may be
emphasized below, any terminology intended to be interpreted in any
restricted manner will be overtly and specifically defined as such
in this Detailed Description section. Those skilled in the art will
appreciate that the disclosure of the present invention may readily
be utilized as a basis for the designing of other similar
structures, methods and systems for carrying out the various
purposes and objectives of the present invention. Thus, the claims
as set forth shall allow for such equivalent constructions insofar
as they do not depart from the spirit and scope of the present
invention as described herein.
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