Wire and cable stripping device

A wire stripping plier has two crossing pivotable arms with hand grips and gripping jaws for gripping the insulation to be stripped from the wire. Two opposing stripping members are provided in the plier, which member can be longitudinally displaced one relative to another upon the pivoting movement of the hand grips towards each other after the insulation has been severed from the wire. Due to this longitudinal displacement the severed insulation is stripped from the wire.

BACKGROUND OF THE INVENTION 
The present invention pertains to an insulation removing device. More 
particularly, this invention relates to a device for stripping insulation 
from wires and cables. 
There are known devices for stripping insulation from wires and cables. 
Conventional devices of the type under consideration comprise two crossing 
hand grips which are pivotable with respect to each other and carry at the 
ends thereof gripping jaws and stripping members which cooperate with each 
other when the grips are pivoted towards one another to produce a cut on 
the insulation and strip the latter from the wire. 
One of such stripping devices is disclosed in the applicant's U.S. Pat. No. 
3,516,307. 
The known devices of the type under discussion are formed as pliers. Such a 
plier is comprised of a plurality of cooperating individual components 
which form a mechanism carrying out the severing and the stripping of the 
insulation. These individual components must be more or less precisely 
fabricated and assembled. This involves considerable expenses. 
Furthermore, high requirements have been established to the functions of 
the components of the plier because during the clamping of the insulation, 
severing it and stripping it from the wire, the wire itself can be 
damaged. The damaged wire, however can break or can be subjected to 
corrosion and therefore can not be used. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an improved wire and 
cable stripping device. 
It is a further object of the invention to provide an insulation stripping 
plier which would include a minimum number of components necessary for 
carrying out its function. 
It is still another object of the invention to provide a cable stripping 
plier, which is inexpensive to produce and which allows to save materials 
and time for its production. 
These and other objects of the invention are attained by a wire and cable 
stripping device, comprising two complementary arms each having at one end 
a handle portion and at the other end a jaw portion carrying a gripping 
jaw; pivot means pivotally connecting said arms intermediate the 
respective ends thereof for movement about a pivot axis normal to the 
elongation of said arms, the gripping jaws being operative for gripping an 
insulated wire to be stripped in response to the movement of said jaw 
portions towards each other; and two opposing stripping members provided 
on the respective jaw portions and operative for severing the insulation 
on the wire, one of said stripping members being displaceable with respect 
to another stripping member and longitudinally thereof in response to a 
further movement of said jaw portions towards each other for stripping the 
insulation from the wire. 
The stripping members may be rigidly mounted on the respective jaw 
portions, whereby the stripping of the insulation from the wire after the 
insulation has been severed from the wire results when said jaw portions 
are closed by said hand portions and upon a mutual displacement of the jaw 
portions longitudinally of each other caused by said further movement. 
Each of said arms may have an intermediate portion between the jaw portion 
and the handle portion, the intermediate portion of one arm being formed 
with a recess through which another arm passes. 
Each of the arms may be formed in the region of the intermediate portion 
thereof with an oblong opening, the oblong openings of two arms being 
connected with each other. 
The above mentioned pivoting means may include a cylindrical pin located in 
said oblong openings and forming a mutual pivot axis for said arms. 
The cable stripping device according to the invention may include spring 
means permanently tending to bias said arms against their movement towards 
each other, said displacement causing said pin to be displaced in said 
oblong openings against the force of said spring means, a path of the 
displacement of said pin corresponding to the sum of the lengths of said 
oblong openings minus the diameter of said pin. 
According to another concept of the present invention the device may 
further comprise an extension piece rigidly connected to one of said 
gripping jaws, the mutual displacement of said jaw portions upon said 
further movement of said handle portions towards each other resulting in 
that, after the insulation has been severed from the wire, one of said jaw 
portions moves relative to said one gripping jaw and said extension piece 
in the direction towards said cylindrical pin whereby said pin slides in 
said oblong openings to an outermost position and said one stripping 
member is dragged by said one jaw portion to strip the insulation from the 
wire. 
The spring means may be a spiral spring. 
The device according to the invention may further include a centering 
element mounted between the intermediate portions of said arms. 
The spiral spring may be wrapped around said centering element and have two 
spread end portions extended towards the respective handle portions of the 
device. 
According to still a further concept of the invention the cable stripping 
device may include a roller arranged in one of said hand portions, one of 
the spread end portions of the spring having a bent end slidable over said 
roller. 
The device may further comprise a connecting element mounted on said 
centering element, said connecting element being operatively connected to 
said extension piece. 
The connecting element may have a projecting finger at one side thereof and 
a plate-like portion at another side thereof, said plate-like portion 
having an opening through which said centering element extends. 
The stripping members each may have an angular recess forming a cutting 
edge, said stripping members overlapping each other in a shearing-like 
fashion when they severe the insulation from the wire. 
One of the gripping jaws may be formed with a projection in the region of 
the recess of the respective stripping member, said projection protruding 
from said one jaw a distance corresponding to the thickness of the 
insulation to be stripped from the wire. 
The device according to the invention may further include cutting elements 
for cutting off the wire and arranged on the jaw portions of the arms 
opposite to each other. 
The novel features which are considered as characteristic for the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages; thereof, will be best understood 
from the following description of specific embodiments when read in 
connection with the accompanying drawing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, and firstly to FIG. 1 thereof, which shows 
the wire and cable stripping device in an initial position, it will be 
seen that the device is generally a plier 1, which has two complementary 
crossing arms 2 and 3 provided with respective gripping jaws 4 and 5 and 
two handle portions 7 and 6, respectively. Two stripping members 8 and 9, 
each having a V-shaped cutting edge, are provided on the arms 2 and 3 
beneath the respective jaws 4 and 5. The handle portion 6, plier arm 3 and 
gripping jaw 5 are integral with each other whereas the handle portion 7 
is integrally formed with an intermediate portion 10 and the plier arm 2. 
Handle portion 7 in said intermediate portion 10 is provided with a 
uniform recess 11 through which the handle portion 6 passes. Both handle 
portions 6 and 7 are hollow; in other words they are double-walled with an 
interspace closed between the walls; outer surfaces of the handle portions 
serve for manipulation by a hand of the operator. The interspace within 
the handle portions serves for accommodating the required movable and 
stationary components of the mechanism of the plier as clearly shown in 
FIGS. 9 and 10. 
Both handle portions or grips 6 and 7 are formed with oblong openings 12 
and 13 into which a common cylindrical pin 14 is loosely inserted, which 
forms a common pivot axis of the grips so that the grips may be turned 
about that pivot axis which extends normal to their elongation. Pin 14 is 
movable back and forth in oblong openings 12, 13 transversely to the 
elongation of the arms upon a corresponding movement of the arms 2 and 3. 
As shown in FIGS. 4, 9 and 10, a cylindrical sleeve-like centering element 
15 is mounted in the interspace of the double-walled handle portion 6, 
oblong opening 12 passing through the centering element 15 whereby the 
latter extends through the above pivot axis. The centering element is 
inserted through a respective bore formed in arm 3 or handle portion 
portion 6 and is secured in the space between the walls thereof against 
rotation. 
The arm 2 of the handle portion 7 has, in the region of connection with the 
intermediate portion 10, an additional inner wall 16 which is formed with 
a slot 17 whereby arm 2 forms in the region of slot 17 a channel 18 as 
also seen in FIGS. 5 and 9. 
Opposing jaws 4 and 5 are formed so as to receive therebetween an end of 
the wire to be stripped. The gripping jaw 5 has a V-shaped configuration 
whereas the gripping jaw 4 is formed so that it registers with the shape 
of jaw 5. As will be seen from FIGS. 5 through 7, a stripping member 9 is 
mounted immediately on the lower side of the gripping jaw 5, the stripping 
member 9 being rigidly arranged in the arm 3. An opposing stripping member 
8 is arranged in the arm 2 and lies behind the inner wall 16 as shown in 
FIG. 1. Member 8 has at one end a cutting tip 19 which abuts against the 
inner wall 16 and at the other end two bent end portions 20 and 21 spaced 
from each other as seen in FIGS. 6 and 7. End portions 20 and 21 of the 
cutting member 8 protrude along the side walls forming the slot 17. 
The stripping member 9 has a V-shaped recess and in the region of said 
recess insignificantly projects over the V-shaped recess of the gripping 
jaw 5 whereby a projection 22 shown in FIGS. 4 and 5 is formed; the 
insulation 38 is held and supported on this projection in jaws 4, 5 after 
the insulation has been severed from the wire and a stripping of the 
insulation from the wire takes place as can be seen in FIG. 4. 
Two handle portions 6 and 7 and arms 2 and 3 therewith are held in the 
initial position shown in FIG. 1 by means of a spiral spring 23 having two 
spread portions 24 and 25. The spiral portion of the spring is 
concentrically positioned around the centering sleeve-like element 15 
(FIG. 10) whereas the spread end portion 24 is supported by a spring force 
on projection 26 formed on the hand portion 6 and another spread portion 
25 is supported by the spring force against a roller 27 provided in the 
hand portion 7 (FIGS. 1 and 10). Particularly, an end piece 28 of the 
spring end portion 25 which is bent in the region of roller 27 can bear 
against the latter. Roller 27 as seen from FIG. 10 is supported between 
the walls of handle portion 7. It is understandable that the hollow 
interspace between the walls of the handle portions is U-shaped. 
An intermediate element 29 is arranged in the middle between the hand 
portion 6 and the arm 3. This element is shown in detail in FIG. 8. The 
element 29 is formed with an extension or finger 30 at one side thereof 
and with a plate-like section 31 at the other side. The plate-like section 
31 is formed with an opening 32 and with a further opening for receiving 
therein a pin 33 which operates as a stop for the spring end portion 24 in 
the initial position of the plier as shown in FIG. 1. 
With reference to FIG. 10 it is seen that intermediate element 29 is 
mounted on the centering element 15 which is received in the opening 32 
with a play so that intermediate element 29 can slide on element 15 and 
pivot thereabout within a required pivoting range. Finger 30 of element 29 
extends into the channel 18 of arm 2 so that it is connected with the 
gripping jaw 4 via an extension piece 34. The extension piece 34 has a 
cross-section which is adjusted to that of the channel 18 formed by the 
wall of arm 2 whereby extension piece 34 can slide in the channel 18. As 
seen in FIG. 9 finger 30 of intermediate element 29 extends into a 
longitudinal recess 50 provided in the extension piece 34 in which finger 
30 is engaged so that extension piece 34 can slide over finger 30. 
Two oppositing cutters 35 and 36 serve for cutting the wire off when the 
hand portions 6, 7 of the plier are pressed together. 
The mode of operation of the stripping device according to the invention is 
as follows: 
In the initial position shown in FIG. 1 arms 2 and 3 of the plier are open 
for an insertion therebetween of the end of the wire 37 with the 
insulation 38 thereon. 
As pressure is exerted on the handle portions 6, 7 in the sense of moving 
these handle portions toward each other, the jaws 4 and 5 will similarly 
move towards one another. Thus the gripping jaws 4 and 5 will engage on 
the insulated wire 38 located therebetween. The insulated wire, however, 
will not be clamped between the gripping jaws 4 and 5. Simultaneously, 
stripping members 8, 9 move one over another in a shearing-like fashion as 
can be seen in FIG. 2; V-shaped recessed cutting edges of stripping 
members 8, 9 cut into the insulation 38 at two opposite sides thereof. The 
depth of the cut, which is limited by overlapping of the stripping members 
8, 9, is such that no damage to the wire can be done. Still further 
movement of the handle portions 6, 7 towards each other will result in 
stripping of the severed insulation 38 from the wire due to the 
longitudinal displacement of the closed plier arms 2, 3 and handle grips 
6, 7 as can be seen in FIGS. 3 and 4. 
In the initial position shown in FIG. 1, prestressed end portions 24 and 25 
of the spiral spring 23 press against the roller 27, projection 26 and pin 
33, respectively. When handle portions 6 and 7 are moved towards each 
other, end portions 24, 25 of the spring at the same time move towards 
each other due to the tension of spring 23 whereby pin 33 and intermediate 
connecting element 29 therewith will be released as shown in FIG. 2. The 
insulation 38 of the wire is, in this position of the plier, severed from 
the wire. 
Upon a continued application of the pressure to the handle portions 6, 7, 
the bent end piece 28 of the spring end portion 25 slides over the roller 
27 in the jerk-like manner, whereby simultaneously the arm 2 which engages 
the severed insulation 38, is, due to the its rigid connection with the 
element 29 and the centering element 15, and together with the stripping 
member 8 rigidly connected thereto, longitudinally displaced relative to 
the opposing arm 3 towards the crossing point while cylindrical pin 14 is 
dragged in the oblong opening 13. 
The path of this displacement corresponds to the whole length of both 
oblong openings 12, 13 minus the diameter of the cylindrical pin 14. When 
handle portions 6, 7 are released, due to releasing of the spiral spring 
23, these portions 6 and 7 open up to a transition point. A complete 
opening of handle portions 6 and 7 and thus the plier takes place 
afterwards by a rapid opening of arms 2, 3 independently through the force 
of the spring 23. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of cable 
strippers differing from the types described above. 
While the invention has been illustrated and described as embodied in a 
wire and cable stripping device, it is not intended to be limited to the 
details shown, since various modifications and structural changes may be 
made without departing in any way from the spirit of the present 
invention. 
Without analysis, the foregoing will so fully reveal the gist of the 
present invention that others can, by applying current knowledge, readily 
adapt it for various applications without omitting features that, from the 
standpoint of prior art, fairly constitute essential characteristics of 
the generic or specific aspects of this invention.