Wire wrap removing tool

A tool removes a wrapped wire conductor from a terminal pin by distorting the configuration of the wire wrap to lessen the frictional contact between the wire wrap and the terminal pin longitudinal edges to permit sliding of the wire wrap along and from the terminal pin.

The present invention relates to hand tools and, more particularly, to hand 
tools for use in the electrical arts. 
Some terminal boards of electrical apparatus include one or more rows of 
terminal pins extending from a base. Electrical conductors or wires are 
often attached to these terminal pins by wrapping the wire thereabout to 
form a helical coil in frictional engagement with the terminal pin. 
Various tools have been developed to accomplish such wrapping. In example, 
U.S. Pat. No. 4,195,401 describes a tool having a slotted hollow tubular 
end for internally receiving the terminal pin and wrapping the wire 
thereabout as the tool is rotated about its longitudinal axis. 
Various hand tools have also been developed to remove a wrapped wire from 
about a terminal pin. In example, U.S. Pat. No. 2,898,952 describes a hand 
tool having a pair of jaws with inscribed screw threaded depressions on 
facing surfaces of the jaws for gripping on existing wire wrap. By 
twisting the tool about the longitudinal axis of the wrapped terminal, the 
wire wrap can be loosened for removal or tightened to re-establish the 
wire wrap about the terminal pin. U.S. Pat. No. 2,998,034 is directed to a 
tool for grasping a wire of an existing wire wrap and unwrapping it 
through rotation of the tool about the longitudinal axis of the wire wrap. 
Various other tools such as needle nose pliers may also be employed which 
simply grasp a free end of the wire wrap and by appropriate manipulation 
of the tool results in partial or complete unwinding of the wire wrap to 
effect disengagement with a terminal pin. 
As will be evident from the above review of the pertinent prior art, all of 
the devices require more or less unwrapping of the wire wrap to permit 
disengagement with the terminal pin. Such unwrapping is labor intensive, 
time consuming and therefore expensive. It may be noted that on a fair 
sized terminal board, several hundred wire wrapped terminal pins may 
exist. 
Various plier-like tools have been developed for certain specialized 
operations. In example, U.S. Pat. No. 129,496 describes a pair of pliers 
wherein one jaw is slotted to accommodate the post of a shoe fastening 
during attachment of the shoe fastening. The device disclosed in U.S. Pat. 
No. 362,981 has a pair of jaws each of which includes a terminal end 
oriented 90.degree. toward the other and one of which is slotted. The pair 
of pliers illustrated in U.S. Pat. No. 1,141,916 illustrates a pair of 
tangs of one jaw intermediate which a tang of the other jaw is oriented to 
effect bending of a wire disposed therebetween. The pliers described in 
U.S. Pat. No. 1,751,165 include a first jaw which includes a slotted 
opening for receiving a second jaw. U.S. Pat. No. 2,700,910 discloses a 
pair of pliers for removing a spring nut by disengaging the tongues of the 
spring nut from the post disposed therebetween. The pair of pliers 
disclosed in U.S. Pat. No. 3,191,840 is particularly adapted for removing 
a split end spring which spring maintains the two ends of a roller chain 
in engagement with one another. U.S. Pat. No. 3,911,583 discloses a pair 
of dental pliers having jaws particularly adapted for engaging tooth 
mounted metal bands and removing same from about the teeth. The pair of 
pliers illustrated in U.S. Pat. No. 4,149,435 effectively punches out the 
knockout identification slug from a key. 
It is therefore a primary object of the present invention to provide a tool 
for removing a wire wrapped about a terminal pin without partial or 
complete unwrapping of the wire. 
Another object of the present invention is to provide a tool for quickly 
and easily loosening a wrapped wire from a terminal pin to permit removal 
of the wire. 
Still another object of the present invention is to provide a tool for 
distending a wrapped wire without unwrapping it to reduce its frictional 
contact with an engaged terminal pin. 
Yet another object of the present invention is to provide a tool for 
reducing the frictional contact intermediate a wrapped wire and a terminal 
pin and urging the wrapped wire into slidable disengagement with the 
terminal pin. 
A further object of the present invention is to provide a tool for removing 
a wrapped wire from a terminal pin in confined quarters. 
A still further purpose of the present invention is to provide a pair of 
pliers specially configured to grasp and remove a wire wrap from about a 
terminal pin without twisting the wire wrap about the longitudinal axis of 
the wrap. 
A yet further object of the present invention is to provide a pair of 
pliers having uniquely shaped jaws for distorting the cross-sectional 
configuration of a helical wire wrap to reduce its frictional contact with 
a terminal pin. 
A yet further object of the present invention is to provide a pair of 
pliers for loosening a wire wrapped about a supporting terminal pin and 
withdrawing the wire wrap from the terminal pin. 
These and other objects of the present invention will become apparent to 
those skilled in the art from the description of the invention below. 
Most terminal pins or posts about which single conductor electrical wire is 
wrapped are rectangular in cross-section. Upon wrapping of the wire, the 
cross-section of the resulting helix is elliptical, elliptical-like or 
oval wherein the contact points between the wire wrap and the terminal pin 
are coincident with the longitudinal edges of the terminal pin. 
Intermediate the edges, the wire wrap is essentially not in contact with 
the terminal pin surfaces. Upon squeezing of the wire wrap at opposed 
points intermediate adjacent edges of the terminal pin, the resulting 
deformation of the helical wrap reduces the force by which the wire wrap 
is in engagement with each of the edges. The reduced force and hence the 
friction intermediate the wire wrap and the terminal pin is consequently 
substantially reduced. The reduced frictional contact will permit lifting 
of the wire wrap off of the terminal pin provided that such lifting is 
effected by applying an upward force at the bottom of the helical wrap. 
The present invention is a tool like a pair of pliers and having jaws 
particularly configured to cause deformation of a helically wrapped wire 
to reduce its frictional contact with an encircled terminal pin and 
includes means for lifting the wire wrap off the terminal pin. 
Particularly, the inner surface of one jaw includes a planar surface for 
bearing against one side of the wire wrap. The inside surface of the 
opposing jaw includes a depression extending from the tip end of a width 
generally coincident with the width of the terminal pin. A bifurcated or 
split foot extends laterally from the jaw to straddle the terminal pin and 
engage the lowermost coil of the wire wrap helix upon upward movement of 
the pliers. 
In operation, the jaws are brought into engagement with a wire wrapped 
about a terminal pin and squeezed, which squeezing tends to flatten or 
distort the helical wire wrap to relieve the force intermediate the wire 
wrap and the edges of the terminal pin. After such distortion and with the 
jaws still maintained clenched, an upward force applied to the pair of 
pliers will act through the bifurcated foot to lift the loosened wire wrap 
from the terminal pin.

Referring to FIG. 1, there is shown a tool 10 configured as a plier-like 
device. The tool includes a pair of jaws 12, 14 which may be brought 
toward and away from one another by commensurate movement of 
interconnected handles 16 and 18 pivoting about a pivot point depicted 
generally by numeral 20. The tool is used to remove a wire wrap 22 around 
about a terminal pin 24 extending from a terminal board 26. Most wire 
wraps comprise a helix of an electrical wire 28 wrapped tightly about and 
in frictional engagement with a terminal pin. Such pins are usually 
rectangular or square in cross-section. The wire wrap itself is maintained 
upon the terminal pin by the friction attendant each wrap of the helix 
contacting each edge of the terminal pin. The wire wrap usually does not 
come into contact with the surface of the terminal pin intermediate 
adjacent edges. 
Tool 10 is positioned with respect to terminal pin 24 so as to cause jaws 
12 and 14 to be disposed adjacent opposed sides of the terminal pin. On 
squeezing of handles 16 and 18, the jaws are closed, which closing tends 
to squash the portion of the wire wrap adjacent the underlying sides of 
the terminal pin while simultaneously forcing laterally outwardly the 
orthogonally oriented opposed parts of the wire wrap. This resulting 
reconfiguration or deformation of the helical wire wrap substantially 
reduces the frictional contact intermediate the wire wrap and the edges of 
the terminal pin. A foot 30 disposed at the lower end of jaw 14 is 
positioned to straddle terminal pin 24 beneath the lower most part of wire 
wrap 22. After handles 16 and 18 have been squeezed resulting in 
deformation of the wire wrap, tool 10 is pulled upwardly which results in 
translation of a lifting force through foot 30 to wire wrap 22 to slidably 
disengage the wire wrap from the terminal pin. Such slidable disengagement 
is possible because of the above-described reduction in frictional contact 
therebetween. In addition, as the wire wrap is a helix the foot will lift 
the lower edge of the lowest coil and cause slight repositioning of each 
of the coils into a more horizontal plane; this will slightly enlarge the 
diameter of each coil. Thus, the formerly required unwrapping of the wire 
wrap is no longer necessary and very substantial time savings may be 
effected through use of tool 10. 
Referring jointly to FIGS. 2, 3, 4 and 5, the details of jaws 12 and 14 
will be described. Jaw 12 may be tapered to a point at tip 32; working 
surface 34 proximate tip 32 is essentially planar. Jaw 14 includes foot 30 
which foot is slotted by slot 36; the width of the slot is preferably 
generally commensurate with the width of terminal pin 24 (see FIG. 1). 
Thereby, the foot is extendable beneath opposed sides of the wire wrap by 
receivingly placing terminal pin 24 within slot 36. Working surface 38 of 
jaw 14 may be planar, like working surface 34 of jaw 12. In a preferred 
embodiment, working surfaces 34 and 38 are parallel to one another and 
aligned with the respective sides of the terminal pin to apply a uniform 
pressure along the full length of the wire wrap on actuation of the tool. 
Thereby, all wraps are uniformly distorted and binding on removal of the 
wire wrap is avoided. 
Alternatively, as shown in the drawings, a slot 40 may be disposed therein, 
which slot is concomitant with slot 36 in foot 30. Preferably, slot 40 is 
of a width the same as or close to that of the width of terminal pin 24. 
With the configuration, on engagement of jaw 14 with a wire wrapped 
terminal pin, edges 42 and 44 of slot 40 bear essentially against the 
resulting adjacent edges of the terminal pin. 
The operative effect of tool 10 will be described with particular reference 
to FIGS. 6a and 6b. Normally, a wire wrap 22 defines a helix about a 
terminal pin 24, which pin is illustrated as being generally rectangular 
in cross-section. The wire wrap extends about the terminal pin to define 
an essentially oval or elliptical shape, which shape is dictated in part 
by the flexibility and deformability of the wire itself. Irrespective of 
the configuration of the oval, it is in frictional contacting engagement 
with the terminal pin essentially only at edges 24a, 24b, 24c and 24d. 
Usually the wire wrap is wound tightly enough to create a substantial 
amount of friction at these four points of contact to prevent sliding 
movement of the wire wrap along the longitudinal axis of the terminal pin 
upon application of any normally expected forces. For this reason, the 
prior art tools have been directed to devices for more or less easily 
unwrapping the wire wrap from about the terminal pin. Such procedure is 
time consuming and therefore labor intensive and expensive. 
Referring particularly to FIG. 6b, pair of arrows 46, 48 illustrate the 
force applied by tool 10 on engagement of jaws 12 and 14 with wire wrap 22 
adjacent the indicated sides of the terminal pin. The resulting squeezing 
force tends to bring the adjacent segments of the wire wrap into closer 
contact with the underlying surfaces of terminal pin 24. This deformation 
results in outward expansion of the remaining segments of the wire wrap, 
as indicated by pair of arrows 50 and 52. The resulting deformation of 
wire wrap 22 also has the effect of reducing the frictional contact 
intermediate the wire wrap and corners 24a, 24b, 24c and 24d. The reduced 
frictional contact now allows the wire wrap to be slidably disengaged from 
the terminal strip by applying an upward force to tool 10, which upward 
force, acting through foot 30 will lift the wire wrap. It is to be 
understood that tool 10 may be operatively engaged with terminal pin 24 in 
the axis opposite to that shown in FIGS. 6a and 6b with equally 
satisfactory results. 
FIGS. 7a and 7b illustrate the operative effect of tool 10 acting upon a 
terminal strip 24 square in cross-section and supporting an essentially 
circular helical wire wrap 22. Here also, corners 24a, 24b, 24c and 24d 
provide the supporting frictional contact intermediate the terminal pin 
and the wire wrap. On application of a force to the wire wrap, as 
indicated by arrows 54, 56, the circular wire wrap will be deformed into 
an oblong shape, as shown in FIG. 7b. The change in configuration lessens 
the frictional force attendant the contact points along the edges of the 
terminal pin through the resulting expansion of the wire wrap in the 
direction indicated by arrows 58 and 60. Again, the wire wrap 22 may be 
withdrawn from the square shaped terminal pin by applying an upward force 
to tool 10 to cause foot 30 to slidably lift wire wrap 22 from terminal 
strip 24. 
Foot 30 is preferably of sufficient extension and slot 36 is deep enough to 
permit the tangs of the foot to extend beneath a sufficient width of the 
wire wrap to apply a uniform lifting force thereacross. Were the tangs of 
foot 30 limited in extension, the lifting force might have the tendency of 
skewing the wire wrap, which skewing would increase the frictional contact 
with the terminal pin due to the misalignment resulting between the wire 
wrap and the terminal pin. 
Should slot 40 not be formed within working surface 38 of jaw 14, the 
invention would still operate as described above. However, it has been 
found by experimentation that after an initial squeezing of the wire wrap, 
the squeezing pressure must be slightly reduced before the wire wrap can 
be readily lifted off. Were the squeezing pressure not reduced, the 
lift-off is more difficult than necessary. By employing slot 40, its edges 
42 and 44 bear essentially against the corresponding edges of the terminal 
strip (in example, edges 24b and 24c) and for reasons not fully presently 
understood, a reduction in the squeezing force is not necessary prior to 
exerting a lifting force and minimal frictional contact intermediate the 
wire wrap and the terminal pin is still obtained. For these reasons, the 
configuration of jaw 14 illustrated is the preferred embodiment of the 
jaw. 
While the principles of the invention have now been made clear in an 
illustrative embodiment, there will be immediately obvious to those 
skilled in the art many modifications of structure, arrangement, 
proportions, elements, materials and components, used in the practice of 
the invention which are particularly adapted for specific environments and 
operating requirements without departing from those principles.