Holder for releasably securing a ferrite core or the like to an electrical power line

A holder for releasably securing a bifurcated core or the like to an electrical power line, the core having two substantially U-shaped portions which are abuttable to form a closed loop that encompasses the power line. An L-shaped boat has at least one leg with an interior configuration that is complementary to one U-shaped portion of the core to receive and hold that one portion. A gantry also having an interior configuration that is complementary to one leg of each U-shaped portion of the core receives both portions and is sufficiently long to permit one leg of each portion to be received while those portions are spaced from each other. The gantry has a guide groove on the exterior thereof for guiding a substantially L-shaped bale which is formed of resilient material and which has one leg that extends over the base of the other portion of the core and another leg which is received by and guided in the groove on the gantry. This other leg of the bale has an end that terminates in a handle which is adapted to be gripped and driven so as to move the portion of the core which is guided in the gantry to abut against the portion which is received in the boat, thereby encompassing the power line. The handle of the bale has a locking ear and the gantry has a locking slot which cooperates with the ear to releasably receive the locking ear, whereby the bale clamps the U-shaped portions of the core together.

BACKGROUND OF THE INVENTION 
This invention relates to a holder for a bifurcated ferrite core or the 
like to permit that core to surround an electrical power line and, more 
particularly, to such a holder that is remotely operable to facilitate 
securing the core to and releasing that core from the power line. 
Preferably, the core is adapted to generate a flux in response to current 
flowing through the power line, this flux being detected by a fault 
indicator so as to provide a fault indication in the event that an 
excessive amount of current flows through the power line. 
Electrical power fault indicators typically are used with high voltage or 
high power electrical lines to indicate an excessive current flowing 
through those lines. Such fault indicators normally are used in 
conjunction with a core, such as a ferrite core, that surrounds the 
electrical power line to generate a flux whose intensity is determined by 
the magnitude of the current flowing through that line. This flux, in 
turn, induces a sensing current which flows through the fault indicator. 
When this sensing current exceeds a predetermined threshold, as when the 
flux in the ferrite core becomes too large due to excessive current 
flowing through the power line, the fault indicator is tripped to 
indicate a fault condition. In this manner, the location of a fault may be 
ascertained by power utility technicians, and the fault condition may be 
rectified. 
Some fault indicators are mechanically coupled to the very same support 
that is used to support or house the ferrite core. Other fault indicators 
are coupled to the ferrite core by electrical conductors, thereby enabling 
the indicator, or meter, to be mounted at a location that is remote from 
the core. In either embodiment, it is necessary to provide some means by 
which the ferrite core may be releasably secured to the power line. In one 
known device, the ferrite core is formed of two separate, abuttable 
U-shaped portions. One portion is coupled to an insulated holder, such as 
a plastic holder, which first is brought into engagement with the power 
line. Then, the other U-shaped portion is brought into abutting 
relationship with the first, and the two portions are clamped together so 
as to form a continuous closed loop which surrounds the power line. 
One disadvantage of the core holder of the aformentioned type is that it is 
difficult to align the two U-shaped portions of the core and then to bring 
those aligned portions together into clamping relationship. Usually, a 
number of tools must be used to effect this aligned clamping relationship, 
and often the holder is not properly restrained on the power line. Also, 
current normally flows through the power line which presents a hazard to 
the technician who is attempting to secure the core thereto. Another 
disadvantage is that the core holder of the aforementioned type is not 
easily manipulated with a "hot stick" that conventionally is used with 
high voltage power lines. 
OBJECTS OF THE INVENTION 
Therefore, it is an object of the present invention to provide an improved 
holder for a core that is releasably secured to an electrical power line 
which avoids the aforenoted disadvantages. 
Another object of this invention is to provide an improved core holder 
which may be used with high voltage fault indicators. 
A further object of this invention is to provide an improved core holder 
which can be easily and safely manipulated by a technician using a "hot 
stick" so as to releasably secure a core to a high power line. 
Various other objects, advantages and features of the present invention 
will become readily apparent from the ensuing detailed description, and 
the novel features will be particularly pointed out in the appended 
claims. 
SUMMARY OF THE INVENTION 
In accordance with this invention, a core holder is provided for releasably 
securing a bifurcated ferrite core or the like to an electrical power 
line, the bifurcated core being of the type having two substantially 
U-shaped portions which are abuttable to form a closed loop that 
encompasses the power line. The holder includes a substantially L-shaped 
boat having an interior configuration that is complementary to one 
U-shaped portion of the core to receive and hold that one portion. A 
gantry parallel to one leg of the boat is coupled to the other leg thereof 
and receives both U-shaped portions of the core. The gantry has an 
interior configuration that is complementary to one leg of each U-shaped 
portion and is long enough to permit both portions to be received thereby 
while spaced from each other. A guide groove is provided on the exterior 
of the gantry for receiving a portion of one leg of a L-shaped bale. This 
bale is formed of resilient material and the other leg thereof extends 
over the base of the U-shaped portion of the core (i.e. that portion which 
is not received by the boat). The leg of the bale which is received by the 
groove on the gantry has an end which terminates in a handle adapted to be 
gripped and driven so as to move the other U-shaped portion to abut 
against the portion received in the boat and, thus, encompass the power 
line. The handle of the bale has a locking ear and the gantry has a 
locking slot which cooperates with that ear to releasably receive said 
ear, whereby the bale clamps the U-shaped portions together.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring now to the drawings, wherein like reference numerals are used 
throughout, FIGS. 1 and 2 are perspective views of the core holder in 
combination with a ferrite core 10, shown particularly in FIG. 2 as 
exhibiting the released condition. The core holder is comprised of a boat 
16 which is of a substantially L-shaped configuration having a base member 
18 and a leg 20 extending therefrom. Boat 16 is adapted to receive 
one-half of ferrite core 10. In particular, the boat is adapted to receive 
U-shaped portion 14 which, as illustrated, is comprised of a base which is 
received by base 18 of boat 16, and two legs 14a and 14b extending 
upwardly from the base. Preferably, the cross-section of the legs is 
substantially circular, and leg 20 of boat 16 is provided with an interior 
configuration that is complementary to this circular cross-section. As 
shown in FIG. 1, leg 20 is formed substantially U-shaped. The free end of 
this leg terminates in a flare section 22 for a purpose to be described. 
The core holder also includes a gantry 24 that is provided with one end 26 
which, when assembled to boat 16, is received by the boat such that the 
gantry extends opposite and parallel to leg 20. The main portion of gantry 
24, that is, that portion extending from end 26, exhibits an interior 
cross-section which is complementary to the circular cross-section of the 
legs of ferrite core 10. As shown in FIG. 1, and as particularly shown in 
FIGS. 4, 5 and 8, the interior cross-section of gantry 24 is substantially 
U-shaped. 
The other half of ferrite core 10, that is, U-shaped portion 12, is 
comprised of two legs 12a and 12b extending from a base. Legs 12a and 14a 
are adapted to be received by gantry 24 and, preferably, U-shaped portion 
14 is adhesively fixed within boat 16, as by a suitable cement or potting 
compound. U-shaped portion 12, however, is permitted to slide within 
gantry 24 from its released position, illustrated in FIG. 2 wherein the 
U-shaped portions are spaced from each other, to the operative position 
illustrated in FIG. 7, whereupon the respective U-shaped portions abut 
against each other. It is a feature of this invention to permit U-shaped 
portion 12 to slide within gantry 24 from the released to the operative 
positions thereof, whereby the core holder and core 10 are fitted about 
and secured to an electrical power line. When the two U-shaped portions 
abut each other, they form a closed loop which, as is recognized, is used 
to sense the current flowing through the power line. 
Gantry 24 is provided with a guide groove 28 on one exterior wall thereof, 
this guide groove extending to a projected portion 30 at the end of the 
gantry opposite end 26. When gantry 24 is assembled with boat 16, guide 
groove 28 is coextensively disposed with a similar guide groove 32 which 
is provided on the wall of base 18 which is opposite leg 20, as clearly 
shown in FIGS. 1 and 2. 
As mentioned above, U-shaped portion 14 is adhesively secured within boat 
16. This is illustrated in FIGS. 2 and 3. U-shaped portion 12 is slidably 
fitted within gantry 24. Although not illustrated in the drawings, a 
conventional O-ring may be provided to assist in the support of U-shaped 
portion 12 within gantry 24. It also is preferred that end 26 of the 
gantry be adhesively secured within boat 16 so as to form an integral core 
holder structure as illustrated in FIGS. 2, 3, 6 and 7. U-shaped portion 
12 is slidable within this core holder. 
A bale 34 preferably is formed of resilient material and is substantially 
L-shaped, with one leg 36 thereof being fitted over and about the base of 
U-shaped portion 12, as illustrated in FIG. 2, and leg 38 of the bale 
being slidable within guide groove 28, including the projected section 30 
thereof. Leg 36 terminates in a bent portion 42 which, as best illustrated 
in FIGS. 3, 5 and 6, engages within a groove 60 which is provided on the 
exterior of leg 12b of U-shaped portion 12. The combination of leg 36 and 
bent portion 42, together with groove 60, permits bale 34 to grip and 
secure U-shaped portion 12 of the ferrite core. 
Leg 38 is seen to terminate in an end 40 which is bent about to form a 
handle 46, this handle having a portion 56 which extends opposite leg 38 
to terminate in a locking ear 48. An intermediate portion of leg 38, that 
is, that portion thereof between leg 36 and handle 40, is provided with a 
step 50. This step is advantageous in the assembly of bale 34 to gantry 
24. 
As indicated by the broken lines in FIG. 1, and as best illustrated in FIG. 
3, a locking slot 52 is provided at the bottom of guide groove 28 so as to 
form a slot or slit through this portion of gantry 24. When bale 34 is 
assembled with U-shaped portion 12 and is fitted within guide groove 28, 
leg 38 extends through locking slot 52, whereas the upper portion of 
handle 56, that is, that section of portion 56 which is adjacent locking 
ear 48, slides in projected section 30 of guide groove 28. Thus, and as 
best shown in FIG. 5, leg 38 and portion 56 effectivley sandwich the base 
portion of projected section 30 of guide groove 28 when bale 34 and 
U-shaped portion 12 are disposed in the released position (FIGS. 2 and 3). 
If a force is exerted on, for example, handle 46 so as to drive bale 34 
from its released position to its operative position, this force on the 
bale tends to drive U-shaped portion 12 toward U-shaped portion 14. The 
bale continues to slide in guide groove 28 and locking slot 52 until 
locking ear 48 extends to the locking slot and, particularly, extends to 
shoulder 54 (FIG. 6). Further force exerted on handle 46 results in 
locking gear 48 being inserted into the locking slot and abutting against 
shoulder 54. At this time, the two U-shaped portions abut each other and, 
moreover, bale 34 is locked by reason of the abutment of locking ear 48 
against shoulder 54, as clearly shown in FIG. 7. It is appreciated that 
the spring bias force exerted in the direction of arrow A in FIG. 7 tends 
to drive the locking ear into the locking slot to abut against shoulder 
54. 
To release the locking effect of the bale and, thus, to permit U-shaped 
portion 12 to slide to its released position, a rotational force should be 
exerted on handle 46 so as to drive locking ear 48 in the direction 
opposite arrow A of FIG. 7. This may be achieved by using a conventional 
"hot stick" or other suitable applicator tool, such as the "Tel-o-pole" 
manufactured by Hastings Fiberglass Products, Inc. of Hastings, MI. When 
the hot-stick tool is inserted into handle 46 and manipulated by a 
workman, portion 56 is urged in the counterclockwise direction, as viewed 
in FIG. 7, so as to release locking ear 48 from abutment against shoulder 
54, thereby releasing the bale which then returns to the position 
illustrated in FIG. 6. The return to this position is due to the spring 
bias force exerted on the bale by reason of the resilient material from 
which it is manufactured. Then, if the hot-stick applicator is driven in 
the left-to-right directions, as viewed in FIG. 6, the bale, together with 
U-shaped portion 12 which is effectively clamped between leg 38 and bent 
portion 42 of the bale, is driven to its released position so as to be 
spaced apart from U-shaped portion 14. Portion 12 is seen to slide within 
gantry 24 so as to be urged from the position shown in FIG. 6 to the 
position shown in FIGS. 2 and 3. To further ensure that portion 12 is 
properly clamped to bale 34, another O-ring (not shown) may be disposed 
about leg 36 and the base of U-shaped portion 12. 
It is seen that flare section 22 at the end of leg 20 of boat 16 is 
provided so as to properly receive and guide leg 12b U-shaped portion 12 
when this portion is driven toward and into abutting relationship with 
U-shaped portion 14. Also, it will be recognized that step 50, which is 
provided in leg 38 approximately midway between leg 36 and 40 end, ensures 
that leg 38 is positioned in locking slot 52 interiorly of gantry 24, 
whereas that portion of the bale between step 50 and end 40 merely is 
guided by guide grooves 28 and 32 and is not positioned within the locking 
slot. 
As illustrated in the drawings, leg 36 is provided with a bend 44 that is 
disposed approximately in the middle section of this leg. This bend 
contacts the base of U-shaped portion 12 and provides resilience when the 
hot-stick applicator pulls on bale 34 in a direction to bring the U-shaped 
portions into abutment and to lock the bale in the gantry. Moreover, the 
combination of bend 44 and step 50 exerts a clockwise rotational force (as 
viewed in the drawings) on U-shaped portion 12. By reason of this force, 
U-shaped portion 12 is angularly biased such that, when this portion is 
brought into abutment with U-shaped portion 14, the end faces of legs 12b 
and 14b abut before the end faces of legs 12a and 14a. Hence, and as shown 
in FIG. 6, the abutment of legs 12b and 14b is accompanied by a small gap 
between legs 12a and 14a. This assures proper alignment of the U-shaped 
portions to each other and, moreover, ensures that the respective legs 
thereof will be brought into proper abutting relationship. It is seen 
that, when legs 12b and 14b abut, locking ear 48 of bale 34 has not yet 
reached locking slot 52. Nevertheless, when an additional force is exerted 
on the bale, as by the use of the aforementioned hot-stick applicator, 
this force tends to overcome the spring bias force exerted by bend 44 on 
the base of U-shaped portion 12, thus bringing the end faces of legs 12a 
and 14a into abutment, and further bringing locking ear 48 into locking 
slot 52 such that this ear now abuts against shoulder 54, as shown in FIG. 
7. 
Although not shown in the drawings, it will be recognized that, if desired, 
a handle may be pivotally mounted on base 18 of boat 16. For example, this 
handle may be U-shaped whose legs are respectively pivotally coupled to 
base 18. Alternatively, this handle may be pivotally coupled to gantry 24. 
In either embodiment, it is preferred that this handle be spring-biased 
such that, when the core holder is used to secure core 10 to an electrical 
power line, this spring-biased handle first is contacted and rotated by 
the power line and, when the core holder is driven to its operative 
position, the biased handle is released so as to clamp the core holder to 
the power line. 
While the present invention has been particularly shown and described with 
reference to a preferred embodiment, it will be readily appreciated by 
those of ordinary skill in the art that various changes and modifications 
in form and details may be made without departing from the spirit and 
scope of the invention. For example, for ease and efficiency in 
manufacturing, it is preferred that U-shaped portions 12 and 14 are 
substantially identical and, thus, symmetrical. However, asymmetrical core 
portions may be used, if desired. Moreover, it is seen that only one 
groove 60 need be provided in, for example, leg 12b of U-shaped portion 12 
in order to receive bent portion 42 of bale 34. The remaining grooves 
which are illustrated but not identified in the core portions may be 
omitted. However, in order to facilitate assembly of the respective core 
portions in the field, it is preferred that such portions be substantially 
identical and, thus, symmetrical. It is for this reason that the remaining 
grooves are illustrated in legs 12a, 14a and 14b. Such grooves may, 
however, be omitted. Also, no specific dimensions of core 10, boat 16 or 
gantry 24 have been mentioned herein. These dimensions are not critical. 
Advantageously, however, gantry 24 is sufficiently long so as to permit 
U-shaped portion 12 to slide therein between its released position (FIGS. 
1, 2 and 3) and its operative position (FIGS. 6 and 7) while still being 
effectively retained by the U-shaped interior of the gantry. Still 
further, in the embodiment illustrated herein, locking ear 48 is seen to 
be substantially parallel to but is disposed above leg 36 of bale 34. If 
desired, this locking ear may be aligned with leg 36 or may be disposed 
beneath this leg. It is important merely that locking ear 48 be driven 
into locking slot 52 so as to abut against shoulder 54 when legs 12a and 
12b of U-shaped portion 12 abut against legs 14a and 14b, as illustrated 
in FIG. 7. That is, locking ear 48 should be driven into locking slot 52 
when handle 46 of bale 34 is driven by, for example, the hot-stick 
applicator, to its locked position. 
Still further, although the preferred application of the present invention 
is to releasably secure bifurcated ferrite core 10 to an electrical power 
line, a more general application is to position two halves of a fragile 
bifurcated loop around a relatively rigid member. 
It is intended that the appended claims be interpreted as including the 
foregoing as well as various other changes and modifications.