Tools – Wrench – screwdriver – or driver therefor – Spanner
Reexamination Certificate
2001-01-04
2004-03-16
Smith, James G. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Spanner
C081S186000
Reexamination Certificate
active
06705182
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to hand tools for manipulating electrical connectors and, more particularly, to a wrench for turning a mechanical grip for a jumper clamp.
BACKGROUND
Background: Electrical Distribution Line Construction Maintenance and Repair
Commonly, an electrical distribution system uses three-phase alternating current (AC) electricity to transmit electrical energy from a generating source to a consumer. Each phase is transmitted over a separate distribution line. Each distribution line is electrically isolated from the other two in order to avoid a short circuit, which would create a potentially hazardous over-current condition.
During the construction, maintenance or repair of electrical distribution lines, it is often desirable and necessary to provide uninterrupted electrical service to a utility's customers. In order to provide uninterrupted service, a method of re-routing electricity around breaks in distribution lines must be used.
A common method of re-routing practiced by linemen in utility maintenance crews is to use a series of jumper wires to reroute the electricity. Either the lineman will climb a utility pole to get to the distribution lines or a bucket truck will lift the lineman up to the distribution lines. The utility lineman will attach one end of the jumper wire to a distribution line, upstream of a switch. The lineman then connects the other end of the jumper wire to another section of distribution line such that the jumper wire, in conjunction with the downstream switch, will electrically bypass the region of distribution line on which the lineman wishes to work. By using a separate jumper wire for each phase, the lineman can re-route all three phases so that uninterrupted electrical service is provided to the utility's consumers even while the lineman make repairs of strings new distribution lines.
Background: Jumper Wire Mechanicals
Linemen use specialized jumper wires for electrical distribution lines. As shown in
FIG. 1A
, the jumper wires
50
typically consist of heavy gauge wire
60
with one heavy-duty connector
100
at each end. Linemen commonly refer to these connectors
100
as “mechanicals.” A typical mechanical
100
is shown in FIGS.
1
B and
1
B′. The jumper wire
60
is usually encased in an electrically nonconductive rubber or plastic material, for example, but portions of the mechanical
100
are bare metal.
Mechanicals
100
for the jumper wire
60
are designed to be tightened by hand, and indeed, that is how linemen presently attach them to distribution lines. As shown in
FIG. 1B
, the typical mechanical
100
has two main components, a metal hook
110
and a grip
120
made of an electrically non-conductive material, for example, plastic. A tail portion
115
of the hook
110
extends into the grip
120
and is connected to the jumper wire
60
. The tail portion
115
is threaded. The inner surface of the grip
120
is threaded so that the grip
120
will travel along the threads of the tail
115
as grip
120
is turned. Metal washer
130
moves in relation to hook
110
as grip
120
is turned. As the metal washer
130
moves towards the hook
110
, electric distribution line
150
is compressed between washer
130
and hook
110
. Grip
120
has a plurality (usually two diametrically opposed) of raised ridges
140
disposed on its periphery that run the length of the grip. Ridges
140
allow the lineman to grasp the mechanical
100
securely and get leverage to turn the grip
120
. Typically, the grip
120
is threaded on its inner surface so that it will easily travel along the threads of the tail
115
. The hook
110
has matching threads so that the grip
120
will move either closer to, or further from, the hook
110
as the grip is rotated. Although the lineman wears rubber gloves, flange
155
reduces the possibility of contact between the lineman's hand and the metal hook
110
, distribution line
150
, or washer
130
. Ideally, the lineman causes the hook
110
to firmly hold a distribution line by rotating the grip such that the distribution line
150
is compressed between hook
110
and washer
130
.
FIGS.
1
C and
1
C′ show a common variation of the jumper mechanical. In this variation, a plurality of protrusions
160
allow the lineman to graph and rotate the grip. The protrusions
160
are typically block-shaped and arranged longitudinally in parallel rows.
Background: Effects of Loose Electrical Connection
No matter how tightly a lineman may tighten a jumper mechanical by hand, it will often loosen due to forces beyond the lineman's control such as wind shaking the distribution lines, or contraction and expansion of the mechanical due to variations in weather. The effects of a loose connection to a distribution line can be catastrophic. Because electrical distribution lines carry high voltages, loose connections to distribution lines can cause dangerous electrical arcing which may bum the lineman or cause interruption of electrical service. High temperatures due to the increased electrical resistance across the loose connection can result in hazardous fires that may end in loss of property or life. Mechanicals and jumpers often are melted completely through by the extreme heat caused by a loose connection. The dangling remnants of the jumper often touch other distribution lines causing a direct short circuit between different phases and a sudden power outage due to the current rush through the short circuit. If the jumper touches television cables or telephone lines, it may also cause damage to many televisions and phones and harm persons using them.
Background: Wrenches
A wrench is a type of tool commonly used to hold or apply rotational force to nuts, bolts, and pipes. Familiar types of wrenches are the open-ended wrench, the monkey wrench, and the Stillson (pipe) wrench. Hundreds of different wrenches have been awarded United States patents, most of them for tools which are adapted to hold or rotate with work pieces with circular or polygonal cross sections.
For example, U.S. Pat. No. 463,137, awarded to Carpenter, discloses an open-end wrench having a jaw with a plurality of transverse notches. The edges of the transverse notches will engage adjacent linear faces of a polygonal nut. The notches allow the wrench to be rotated to obtain a fresh hold on the nut without removing the wrench from the nut.
For example, U.S. Pat. No. 1,624,508, awarded to Reilly, discloses an open-end, fixed jaw wrench which can hold nuts and bolts of various sizes. The wrench of Reilly has one jaw with a smooth face and an opposite jaw with a stepped face. The steps are sized so that the jaws will engage the flat faces of various sizes of polygonal nuts.
For example, U.S. Pat. No. 2,334,069, awarded to Collins, et al., discloses an open end wrench designed to turn coupling nuts for joining hoses such as fire hoses or oil hoses. This wrench is intended to be used with three general types of coupling nut, all of which have diametrically opposed pegs (lugs). The head of the wrench has a cavity that fits over one peg on the coupling nut. In addition to engaging one peg, the wrench has a working face that engages the perimeter of the coupling nut somewhere between the two pegs.
Prior inventions appear to have focused almost exclusively on wrenches which can hold or rotate nuts, bolts, or pipes. There has been a conspicuous lack of wrenches created to accommodate work pieces which have protruding features. In particular, there has not been an adequate wrench designed to manipulate jumper mechanicals.
SUMMARY OF INVENTION
One or more of the disclosed embodiments provides at least the following advantage: a tool for improved manipulation of jumper mechanicals.
One or more of the disclosed embodiments provides at least the following advantage: a tool that will work with many different jumper mechanical grips.
One or more of the disclosed embodiments provides at least the following advantage: a tool that may be used easily and safely in the confines of a bucket truck.
One or
Conley & Rose, P.C.
Smith James G.
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