Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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1 This invention relates to a tool. for stripping the
insulator COVerinCJ formecl of an insulative materi.al such as
rubber or vinyl chloride from a covered electr.ical wire.
The conven-tional tool of this typc- used for stripping
insulating coating from covered electrical wires comprises an
electrical wire holding mechanism consisting of upper and lower
jaws at the leading ends o a pair of handles pivotecl to
each other for opening and closing and a pair of upper and
lower cutting blades movable to cut into the insulator
coating on the wire and then strip the cut insulator coating
from the wire core. Such type of insulator coating stripping
tools are disclosed in U.S. Patent Nos. 3,125,908 and
3,146,645, for example. However, the tools as disclosed in
the above-mentioned U.S. patents have the disadvantage that
since the upper and lower jaws and the upper and lower
cutting blades are positioned in substantially the same
plane as the handles lie, the leading end of the wire
gripped by the two jaws and nipped by the two cutting blades
is interrupted by the handles and therefore, the length
o a covered electrical wire from which the insulator
coating is to be removed is limited and the insulator coating
covering the covered electrical wire can not be stripped off
for a substantial distance along the length of the core
wire.
And the prior art tools also have the disadvantage
that when the insulator coating is stripped off the covered
electrical wire, *he wire gripped between the upper and lower
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1 jaws is frequentl~ displ~ced in~dverten-tly and the cutting
posi~i.on on -the insulator coa-ting varies resul-ting in improper
stripping of the insulator co~ting. Furthermore, the
prior ar-t tools have the disac~vantage that since such tools
include a mechanism adapted to move the two cutting blades in
the axial direction of the wire and th~ upper and lower jaws
are formed as parts separate from the handles, the con-
struction is complicated and not compact and does not have
sufficient rigidi.ty. Furthermore, since the prior art tools
are designed for use with only a covered solid wire, the
tools can not strip the sheath from a flattened covered
electr.ical wire including a plurality of covered core wires.
Therefore, one object of the present invention is
to provide a tool for stripping the insulator coating from
a covered electrical wire in which the insulator coating
stripping operation is not interrupted by the handles
whereby the insulator coating can be stripped from the core
wire for a substantial distance along the length of the core
wire.
Another object of the present invention is to pro-
vide a tool for stripping the insulator coating from a
covered electrical wire in which when the insulator coating
is to be stripped from the covered electrical wire, the tool
is positively prevented from slipping from the cutting .
position on the insulator coating to thereby ensure cutting-
off the proper length of insulator coating,
Another object of the present invention is to
provide a tool for stripping the insulator coating from a
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1 covered electrlcal wire whi~h has a simp~e and compact but
rigid mechani~m.
Anothe~ object of the presen-t inven-t:ion i,5 to
provide a tool -for s-trippi.ng the insulator coating from a
covered electrical wire which can be simply operated.
Another object of the present invention is to pro-
vide a tool Eor stripping the insulator coating from a
covered electrical wire which is easily adaptable for
stripping a covered electrical wire of the insulator coating
and also for stxipping the sheath from a flattened covered
electrical wire including a plurality of covered wire cores.
According to the present invention, a tool is pro-
vided for stripping the insulator covering from a covered
electrical wire in which the main body of the tool comprises
a first handle having a lower jaw at the leading end and a
second handle pivoted to the first.handle by means of a shaft
and a wire holding mechanism:adapted to.grip the wire upon
closing of the t~Jo handles and cutting blades adapted to
cut into the insulator coverlng on the covered electrical
wire and pull the cut insulator covering off of the core
wire along the length of the handles upon the closing of
the handles are pxovided at the leading end portion of the
main body projecting laterally of the handles.
The above and other objects and attendant advantages
of.the present invention will be more readily apparent to
those skilled in the art from a reading of the following
detailed description in conjunction with the accompanying
drawings which show one preferred embodiment of the invention
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1 for illustration purpose only, but not for :Limiting the
scope of -the same in ~ny way.
E'ic~. 1 is a side elevational view of one embodiment
of the invention showiny the kool for stripping the insulating
covering from a covered electrical wire with a portion thereof
broken away;
Fig. 2 is similar to Fig. 1, but shows the upper
cutting blade and the associa-ted stripping blade in their
lowered position;
Fig. 3 is similar to Fig. 2, but shows the associated
stripping blade in its stripping position;
Fig. 4 is an end elevational view of the tool in its
condition as shown in Fig. 3; and
Fig. 5 is a perspective view of the tool as shown
in Fig. 1 with a portion thereof broken away.
The present invention will be now described by way
of the accompanying drawings which show the preferred
- embodiment of the tool.
In Figs. 1 and 5, reference numeral 1 denotes an
upper handle of U-shaped cross-section having a lower jaw 2
integral with the leading end of the handle and the lower jaw
has at the leading or free end thereof a lower holding portion
3 extending from the forward end of the lower jaw 2 and
also projecting laterally of one surface 1' of the upper
handle 1 and one surface 9' of a lower handle 9 of U-shaped
cross-section. The upper surface 3' of the holding portion 3
is provided with a groove 6 in which the roots of a lower
cutting blade 4 and a plurality of guides 5 are held in
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l position. Thus, -the lower cut-ting b:la~e ~ and guide 5 are
also positioned for projecti.ng later~ of the sur:Eaces l'
and 9' of -the upper and lower handles l and 9, respec-tively.
A portion of the lower cutting b:Lade ~ on one s;.~e thereof
is provided with one or more arcuate blade edyes 7 (each b].~de
edge 7 is adapted to cu-t into the insulating covering on a
covered solid wire) and another portion of the lower
cutting blade on the other or opposite side thereof is
provided with a blade edge 8 in the forrn of an elongated
recess having the depth greater than tha-t of the arcuate
blade edges 7. The blade edge 8 has a flattened bottom and
- is adapted to cut into the insulating covering of a
flattened covered electrical wire such as a flattened vinyl
sheathed cable. The guides 5 are secured to one or the
outer end of the outermost arcuate blade edge 7, one or the
outer end of the blade edge 8 and the boundar~ between one
or the outer end of the innermost arcuate blade edge 7 and
the other or inner end of the blade edge 8, respectively,
in the illustrated embodiment. The leading end of the lo~7er
handle.9 is pivoted by means of.a stub shaft lO to the
intermediate position of the upper handle l where the rear
end of the lower jaw 2.is positioned. Disposed about the
stub shaft lO is a return spring 13 having one end abutting
against a groove ll formed in the middle portion of the upper
handle l and the other end abutting against the inner surface
of the U-shaped lower handle 9. Reference numeral 14
denotes an elongated guide opening formed in substantially
the central portion of the length of the upper handle 1 and
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1 a gu:ide member 15 is received in the guide opening ].~ and
is pi.voted in suhs-t:ant:ially the central portion thercof to
the upper handl~ 1 by means of a transverse holt 16. Pxovided
at -the leading end oE the yuid~ member 15 i~ an upper
holding portion 17 which projects laterally o~ the surfaces
1' and 9' of the upper and lower handles 1 and 9, respectively
like the lower holding portion 3. The upper holding portion
17 is adapted to move toward the lower holding por-tion 3 as.
the lower handle 9 is pivoted in the di.rection toward the
upper handle 1 as will be described hereinaf-ter. The under-
surface 17' of the upper holding portion 17 faces the upper
surface 3' of the lower holding portion 3 and thus the
surfaces 17' and 13' of the upper and lower holding portions
17 and 13 provide an electrical wire holding mechanism which
clamps the wire as the lower handle 9 approaches the upper
handle 1. A stop member 18 is integrally formed on one side
of the upper holding portion 17 and projects downwardly a
smail distance from the undersurface 17' of the holding
portion 17 ~Figs. 1 and 4). The stop member 18 functions
to limit the pivotal movement of the guide member 15 as the
guide member pivots about the axis of the bolt 16 in the
counter-clockwise direction as seen in Figs. 1 to 3 inclusive
by means of an interlocking rod 21, the descriptlon of which
will be given hereinafter, when the upper and lower handles
1 and 9 are closed and when the guide member has pivoted
by a predetermined angular distance in the counter-clockwise
direction, the lower end of the stop member 18 abuts against
the upper surface 3' of the lower holding portion 3 to
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1 prevent the guide member 15 from Eurther pivotiny. The
undersurface 17' of the upper holding por-tion 17 is provided
with recesses 19 for receiving the upper ends oE the guides 5
during the insulating coveriny stripping operati.on. An
anti-slip member 38 is securely provided on the holding
portion along the front surface of an upper cutting blade
30 the description of which will be given hereinafter. The
anti-slip member 38 has a pointed leading edge which is
adapted to abut against the cut end edge of the insulating
covering remaining on the electrical wire when, after the
cooperating lower and upper blades ~ and 30 cut into the in-
sulating covering, the upper bla~e 30 is moved so as to
remove.the coating from the wire. Instead of providing
such the anti-slip member 38 on the holding portion 17,
serrations can be provided on the undersurface 17' of the
upper holding portion 17 and on the upper surface 3' of
the lower holding portion 3 for preventing the electrical wire
from slipping off. ~.
The rear portion of the above~mentioned guide
member 15 is provided with a slot 20. Reference numeral 21
denotes a connector rod which is pivoted at the lower end
to the lower handle 9 in substantially the central
portion of the latter by means of a stub shaft 22 and is
also pivotably supported on a pin 23 loosely received in
.25 the slot 20 in the guide member 15. .By the provision of the
connector rod 21 in the manner described above, the guide
member 15 is pivotably connected to the lower handle 9 by
the connector rod 21. Disposed a~out the p.in 22 is a spring
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1 24 whi.ch has one end ahllttiny ayainst the inner surface of
the lower handle 9 and the other end abu~ting against the
connector rod 21 whereby a resilien-t force acts on -the rod
21 in the counter-clockwise direction as seen in Figs. 1
to 3 inclusive.
~ hen the gripping force applied to the upper and
lower handles 1 and 9 is removed therefrom, the above-mentione
spr.ing 24 and also spring 13 recoil to cause the lower handle
9 to pivot about the pin 10 in the clockwise direction as
seen in Figs, 1 to 3 inclusive which in turn causes the
connector rod 21 to pivot about the pin 22 in the counter-
clockwlse direction to thereby move the pin 23 of the
upper end of the rod leftwards within the slot 20. Referenc~
numeral 26 denotes an upper cutting blade holder having an
upper cutting blade support portion 27 for holding the
upper cutting blade 30 at the leading end and received in
the guide opening 14 in parallel with the guide memher 15.
The upper cutting blade holder 26 has an elongated slot 28
in substantially the central portion thereof for loosely
receiving the above-mentioned bolt 16 and also a through
bore- 29 in the rear portion for pivotably receiving the
above-mentioned pin 23. Thus, the upper cutting blade
holder 26 is also pivotably connected to the upper handle 1
and further pivotably connected at the rear end to the lower
handle 9.by means of the connector rod 21. The upper cutting
blade support portion 27 is positioned behind the holding
portion 17 and projects laterally o~ the surfaces 1' and
9' of the upper and lower handles.l and 9 in the same direction
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1 as the holding portioll 17. 'rhe front sur.Eace 27' of the
blade support portion 27 has the upper cutting blade 30
secured thereto in oppos:ition to -the lower cutting blade 4
and -the upper blade 30 secured there-to ln opposition to the
lower cutting blade 4 and the upper blade 30 cuts into the
insulating covering on the electrical wire together with
the lower cutting blade 4. Like the lower cutting blade 4,
the upper cutting blade 30 projects laterally of the surfaces
1' and 9' of the upper and lower handles 1 and 9. ~ portion
of the cutting blade 30 on one side thereof is provided with
a plurality of arcuate blade edges 31 which correspond in
number to and are aligned with the blade edges 7 on the
lower cutting blade 4. Thus, the edges 31 are complementary
to the cutting edges 7. Another portion of the cutting blade
30 on the other or opposite side thereof is provided with an
elongated blade edge 32 which is complementary to and in
alignment with the edge 8 on the lower cutting blade 4.
Reference numeral 33 denotes an insulating covering stripping
member which is adapted to abut against the end surface of
the insulating covering on the electrical wire where the
lower cutting blade 4 has cut and move together with the
upper cutting blade 30 in parallel to the longitudinal
direction of the upper and lower handles 1 and 9 to thereby
aid the stripping of the insulating covering. ~he stripping
member 33 has a stripping portion 34 at the leading end and
a slot 35 in the rear portion and is positioned between the
guide member 15 and the upper cutting blade holder 26 within
the guide opening 14. Like the upper cutting blade holder 26,
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1 the strippin~ Inern~er 33 is a:Lso provi.ded in substclnti.ally
the central portion thereof witll a slot 36. The bolt 16
extends loosely through the sl.ot 36 to pivotably connect -the
member 33 to the ~Ipper handle 1 and thc pin 23 extends
loosely through the rear slot 35 to pivotably connect the
member 33 to the central portion of the lower handle 9 through
the connector rod 21. And as more clearly shown in Fig. 5,
the ~tripping member 33 projects laterally of the surfaces 1'
and 9' of the upper and lower handles 1 and 9 behind the
lower cutting blade 4 in the same direction as the lower
holding portion 3. In the initial stage of the stripping
operation, the leading end of the stripping portion 34 of
the stripping member 33 is in engagement with the inner side
of the lower cutting blade 4. If necessary or desired, a
stripping blade 37 may be attached to the stripping portion
34 projecting laterally of the surfaces 1' and 9' of the upper
and lower handles 1 and 9 like the lower cutting blade 4.
The blade edge of the stripping blade 37 extends parallel
to the lower cutting blade 4 and.has a configuration
corresponding to the blade edges 7 and 8 so as to cut into
the insulating covering of the electrical wire in cooperation
with the blade edges 7.and 8.
With the above-described construction and
arrangement of the components of the tool, in operation, a
covered electrical wire from which the sheath or covering
is to be removed such as a flattened.covered electrical wire
is passed into the space between the guides 5 from the front
thexeof ox from one side of the guides with the axis of the
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1 wire ex-tendincJ in the longi~udi,nal direction oE -the handles
1 and ~ in the position of -the tool as shown in Fig. 1
wherein the lower hand]e 9 is its fully open position. As
the covered wire is passed between -the yuides 5, a par-ti-
cular or predetermined area of the wire is posi-tioned on
the blade edge 8 of the lower cutting blade 4. Then, the
operator grips the upper and lower handles 1 and 9 to pivot
the lower handle 9 about the pin 10 in the counter-cloc]cwise
direction (as seen in Fig. 1) against the force of the
lC spring 13. The pivotal movement of the lower handle 9 in
the counter-clockwise direction raises the connector rod 21
pivoted to the lower handle 9 by the counter-clockwise spring
force of the spring 24 and the rising connec-tor rod 21
pushes upwardly the rear portion of the guide member 15 by
means of the pin 23 at the upper end of the rod 21. Thus,
the guide member 15 pivots about the bolt 16 in the counter-
clockwise direction as seen in Fig. 1 and the upper holding
portion 17 moves downwardly toward the lower holding
portion 3 on the upper handle 1 to grip the covered wire
between the ~nti-slip member 38 on the undersurface of the
upper holding porti,on 17 and the lower holding portion 3.
Simultaneously with the upward movement of the connector
rod 21, the rear portion of the upper cutting blade holder
26 is also pushed up by the pin 23 to pivot about the bolt
16 in the counter-clockwise direction as seen in Fig. 1 to
thereby move the upper cutting,blade 30 supported by the
upper blade.-support poxtion 27 downwardly toward the lower
cutting blade 4 on the lower holding portion 3. On the
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1 othe~ hand, since t}-le slot 35 in th~ rear portion of the
stripping member 33 extends in the same direction as the pin
23 moves upwardly ancl thus, since the pin 23 moves upwardly
along the slot 35, no pivotal movement o:E -the stripping
member 33 will occur whereby the stripping portion 34 is
held in con-tact wi~h the lower holding portion 3 with the
stripping blade 37 disposed adjacent to the lower cutting
blade 4. When the lower handle 9 is moved upwardly in the
manner described above, the upper blade 30 is caused to be
pressed against the flattened covered wire positioned on
the lower cutting blade 4, the upper ends of the guides 5
enter the corresponding recesses 19 in the undersurface 17'
of the holding portion 17, the blade edges 8 and 32 of the
lower and upper cutting blades 4 and 30, respectively, cut
into the insulating covering on the covered electrical wire
and at the same time, the anti-slip member 38 provided on the
undersurface o~ the upper holding portion 17 along the
forward sur~ace of the upper blade 30 and the stripping
blade 37 positioned adjacent to the inner side o~ the lower
cutting blade 4 also cut into the insulating covering.
When a cut has been made in the insulating covering to a
predetermined depth, the lower end o~ the stop member 18
on the guide member 15 caused to abut against the upper
surface 3' o~ the lower holding portion 3 on the upper handle
1 as shown in Fig. 2 to terminate the pivotal movement of
the guide member 15 and the upper cutting b].ade holder 26.
In this condition of the tool, the slot 20 in the guide
member 15, the slot 28 in the upper cutting blade holder 26
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1 and the slot 36 in the stripping member 33 are disposed in
parallel to each other in the longitudinal direction of
the upper handle 1. Therea~ter, as the lower handle 9 is
further pivoted upwardly, the lower end of -the connector rod
21 is also moved upwardly, because -the lower end of the rod
is pivoted to the lower handle 9 by the stub shaft 22.
However, since the upper end of the connector rod 21 is
connected to the guide member 15 which is now stationary by
means of the pin 23 engaging in the guide member slot 20,
the pin 23 moves rightwards as seen in Figs. 1 to 3 inclusive
along the slot 20 as the connector rod 21 moves upwardly.
Thus, the connector rod 21 pivots about -the stub shaft 22 in
the clockwise direction as seen in Figs. 1 to 3 inclusive
against the force of the spring 24. The rightward movement
of the pin 23 along the slot 20 causes the upper cutting
blade holaer 26 pivoted in the rear portion to the pin 23
to move rightwards as seen in Figs. 1 to 3 inclusive under
the guidance of the bolt 16 loosely received in the slot 28
formed in the central portion of the holder 26 and at the
same time, the stripping member 33 having the pin 23 received
loosely in the slot 35 also moves rightwards as seen in
Figs. 1 to 3 inclusive under the guidance oE the bolt 16
received loosely in the slot 36 in the central portion o~
the member 33 together with the upper cutting blade holder
26 parallel to the latter. This movement of the members 26
33 causes the upper cutting blade 30 and stripping blade 37
which have cut into the insulating covering on the covered
electrical wire to move simultaneously and parallel to each
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1 other in the axial direction of the ~lattened covered
elec-trical wire which e~ten~s in the lonyitudinal direction
of the upper and lower handles 1 and 9 -to assume the position
as shown in Fig. 3. At this time, since the covered
electrical wire is gripped by the wire holding mechanism
comprised o~ the holding portions 3 and 17 and ~urther
since the cut end edge formed on the insulator coating
thereof is restrained by the anti-slip member 38 and the
lower blade 4, as the upper cutting blade 30 and stripping
blade 37 move so as to pull the cut insulating covering off
of the wire core toward the rear portions of the handles,
the displacement of.the cut end is prevented and the covered
electrical wire can be positively stripped of the insulating
covering from the cut end edge. Thereafter, when the gripping
fbrce applied to the handles 1 and ~ is released the above-
described sequence of operations is reversed, that is, first
of all, the lower.handle 9 is caused to plvot downwardly in
the clockwise direction as seen in Figs. 1 to 3 inclusive
under the force of the springs 13 and 24 and the connector
rod 21 is also caused to pivot downwardly in the counter-
clockwise direction as.seen in Figs. 1 to 3 inclusive under
the force of the spring 24 whereby the upper cutting blade
holder 26 holding the upper cutting blade 3~ thereon and
the stripping blade holder 33 holding the stripping blade
37 thereon simultaneously move leftwards as seen in Figs. 1
to 3 inclusive in parallel to each other to the position as
- shown in Fig.2. As the lower handle 9 further continues to
pivot:.downwardly, the connector rod 21 also pivots downwardlyt
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1 and the guide member 15 and upper cu-tting blade holder 26
pivot downwardly in the clockwise direc-tion to the position
as shown in Fig. 1 whereby the flattened covered elec-trical
wire from which the insulating covering has been removed is
released to thereby complete the stripping operation. When
a covered solid wire is subjected to the stripping treatment,
the wire is positioned on the arcuate blade edge 7 of the
lower cutting blade 4 in the same manner as described in
connection with the insulator coating stripping treatment on
the flattened covered electrical wire and the lower handle 9
is gripped to be pivoted upwardly toward the upper handle 1,
the blade edge 7 of the lower cutting blade 4, the blade edge
31 of the upper cutting blade 30 and the stripping blade 37
cut into the insulating covering on the covered solid wire to
a predetermined depth and the upper blade 30 and stripping
blade 37 move.along the core wire whereby the insulator.
coating is pulled off the core wire.
As is clear.from the foregoing, according to the
present invention, by placing a covered electrical wire from
which the insulating covering is to be removed onto the holding
portion of the lower ~aw and then gripping the lower handle
to cause the handle to:pivot-upwardly, the insulating
covering stripping. operation is performed in the axial
direction of the wire and thus, the stripping can be
efficiently performed even in a limited space. And since
the upper and lower cutting blades project laterally of the
side surfaces of the upper and lower handles, the electrical
wire positioned between the upper and lower cutting blades
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1 will not impede the movemen-t of the handles, -the lower
cuttin~ blade can be positioned in any desired position
along the wire to thereby ensure positive stripping o~ the
insulator coating coveriny a substan-tial distance in the
longitudinal direction of the wire. Furthermore, during
the stripping of the insulator coating, since the anti-slip
member and lower cutting blade abut against the cut edge on
the insulator coating, the wire is held against movement
and displacemen-t to thereby ensure positive cut off of the
insulating covering from a precise position thereon. And
since the lower cutting blade is secured to-the lower jaw
which is integral with the leading end of one of the handles
and does not move during the stripping operation, the
construction o~ the tool can be made simple and rigid.
Furthermore, since the guide member, upper cutting blade
holding portion and stripping member are mounted on the
handle by the common shaft and operated by the common
connector rod, the operation mechanism of the tool is simple
and compact and can be operated in a simple manner. Further-
more, since the complementary arcuate blade edges are providedon the opposing upper and lower cutting blades in adjacent
opposing upper and lower cutting blades in adjacent opposing
relationship for stripping a flattened covered electrical
wire of the insulator coating, the insulating covering can
be-stripped off of a flattened covered electrical wire com-
prisirg a plurality of covered wires as well as a covered
solid wire.
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1 While only one embodiment of the inven-tion has been
shown and described in detail, it will be understood that the
same is for illustration only and not to be taken ~s a defi~.
nition of the invention, reference being had for this purpose
to the appended claims.
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