Joints and connections – Articulated members – Including static joint
Reexamination Certificate
1998-06-08
2001-05-08
Browne, Lynne H. (Department: 3629)
Joints and connections
Articulated members
Including static joint
C403S152000, C403S154000, C174S043000, C174S0450TD
Reexamination Certificate
active
06227749
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a swivel base assembly for connecting an insulator to a support structure, and in particular, a swivel base assembly for connecting a strut insulator of a “horizontal-V” to a vertical support structure.
BACKGROUND OF THE INVENTION
Power transmission lines are used to transmit power from power generation plants to substations and other power consumption facilities. The power transmission lines are suspended from towers or poles using several types of well-known installations. The horizontal-V is one of those well-known installations. As shown in
FIG. 1
, a strut insulator (
1
) extends horizontally from a utility pole (
2
) and a stay insulator (
3
) extends at an angle from a point on utility pole (
2
) above the point where strut insulator (
1
) is connected to pole (
2
). The two insulators are joined together at their distal ends, and a conductor (
4
) is suspended from the joined distal ends. The appearance of the strut and stay insulators mounted on the pole is what gave rise to the horizontal-V name.
The weight of the conductor (
4
) and other hardware (e.g., anchor shackle, suspension clamp, link, armor rod, and the like) results in stay insulator (
3
) being in tension and strut insulator (
1
) being in compression. As such, different insulator structures are usually employed for the stay and strut insulators; the former must withstand tensile forces, and the latter must withstand compressive forces.
It is necessary to mount the insulators on the pole in a manner that will allow the fixed ends of the insulator to pivot in the event of line movement. For example, a wind gust may cause the transmission line to move vertically (up and down in the plane of
FIG. 1
) as well as longitudinally (in and out of the plane of FIG.
1
). It is preferred that the mounting structures used to connect the insulators to the pole pivot at the fixed ends of the insulators in order to relieve any impact shock in the insulator due to movement of the conductor. Otherwise, extreme movement of the conductor could result in damage to the insulators.
It is relatively easy to connect the stay insulator to the pole since that insulator is subjected mainly to tensile forces. One connection method uses an anchor shackle (
5
) connected to the tower or an extension thereof. The anchor shackle is connected to a similarly configured metal fitting (
6
) on the stay insulator. This arrangement allows adequate vertical and longitudinal pivoting at the fixed, tower end of the stay insulator.
The strut insulator presents unique mounting problems, however, due to the compressive forces imposed by the weight of the conductor and associated hardware. Various types of mounting assemblies (
7
) have been used to connect the strut insulator to the pole.
FIGS. 2
a
and
2
b
show top and side views, respectively, of one example of such a mounting assembly.
The mounting assembly shown in
FIGS. 2
a
and
2
b
includes a base (
20
) that is secured directly to a utility pole (
2
) by fastening bolts (B) through holes (
21
) passing through the vertical leg (
22
) of base (
20
). A coupling plate (
23
) is pivotally mounted on base (
20
) via a vertical oriented bolt (
24
) extending through holes (
25
) and (
26
) passing through horizontal legs (
27
) and (
28
) of base (
20
). The bolt (
24
) defines an axis about which the strut insulator can pivot in the longitudinal direction (in and out of the plane of
FIG. 2
b
). A bolt (
29
) passes through the clevis fitting (
30
) of the strut insulator, and through coupling plate (
23
) to connect the strut insulator to the mounting assembly. Bolt (
29
) defines an axis about which the strut insulator can pivot in the vertical direction (up and down in the plane of
FIG. 2
b
).
While this mounting assembly provides the necessary longitudinal and vertical pivot axes for the strut insulator, it provides insufficient space between base (
20
) and coupling plate (
23
) for the bolts used to mount the assembly to a utility pole. Specifically, in order to insure reliable connection to utility pole (
2
), the pole mounting bolts (B) extending from pole (
2
) to receive the base (
20
) of the mounting assembly is preferably capped with locking means (e.g., a double nut, lock washer, cotter pin, etc.). As such, bolts (B) necessarily extend a relatively large distance beyond the surface of the vertical leg (
22
) of base (
20
). The extension of pole mounting bolts (B) often times interferes with the attachment and pivotal movement of coupling plate (
23
).
Installation of the mounting assembly shown in
FIGS. 2
a
and
2
b
to utility pole (
2
) also tends to be cumbersome, since the mounting holes (
21
), positioned within the confines of vertical legs (
27
) and (
28
) of base (
20
), can be difficult to access. Moreover, assembly of vertical bolt (
24
) requires an additional step, especially since a nut or cotter pin is usually employed to retain bolt (
24
) within holes (
25
) and (
26
) formed through base (
20
).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a swivel base assembly for mounting an insulator to a support structure in an easy and efficient manner. In accordance with one embodiment of the present invention, a swivel base assembly is provided that includes a base member having a pair of opposed bearing seats spaced apart from one another in alignment along a bearing axis, and a one-piece coupling member having a first end received within the pair of opposed bearing seats and a second end adapted to be coupled to the insulator. The first end defines a first pivot axis for the insulator and the second end defines a second pivot axis for the insulator, wherein the first pivot axis is substantially coincident with the bearing axis and the second pivot axis is substantially perpendicular to the first pivot axis. The assembly also includes means for securing the base member to the support structure.
It is preferred that the base member include first and second half bearing members separable from one another, wherein the first half bearing member has one of the pair of bearing seats formed therein, and the second half bearing member has the other one of the pair of bearing seats formed therein. In this preferred embodiment, the means for securing includes at least one hole passing through each of the first and second half bearing members, and each hole intersects an extension of the bearing axis. More preferably, the holes passing through the half bearing members are spaced, along an extension of the bearing axis, a distance sufficient to prevent intersection between an imaginary cylindrical extension of each hole and any portion of the coupling member.
It is also preferred that the first half bearing member have a first mating surface, and the second half bearing member have a second mating surface. The mating surfaces are substantially complementary to allow the first and second half bearing members to engage one another to define the base member.
The use of a one-piece coupling member that functions to define both the longitudinal and vertical pivot axes allows for easier installation on a utility pole or tower. Moreover, by positioning the mounting holes in the base member in spaced relation to the zone in which the coupling member pivots the bolts extending from the utility pole do not interfere with the pivotal movement of the coupling member.
These and other objects of the present invention will be understood more clearly after reading the following description and appended drawings.
REFERENCES:
patent: 1396324 (1921-11-01), Gieseke
patent: 1409954 (1922-03-01), Johnston
patent: 2551136 (1951-05-01), Keltner
patent: 3296358 (1967-01-01), Fiero et al.
patent: 3342925 (1967-09-01), Lewis et al.
patent: 3538237 (1970-11-01), Hockaday
patent: 3596947 (1971-08-01), Ishihara
patent: 3850533 (1974-11-01), Thielen
patent: 4711461 (1987-12-01), Fromberg
patent: 5036162 (1991-07-01), Zajfert
patent: 2 099 547 (1982-12-01), None
SU 525-167 (Insulator Fittings), Nov. 12,1976, Basic
Bochna David E.
Browne Lynne H.
Burr & Brown
NGK Insulators Ltd.
LandOfFree
Swivel base assembly for connecting insulator to support... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Swivel base assembly for connecting insulator to support..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Swivel base assembly for connecting insulator to support... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2532932