Note: Descriptions are shown in the official language in which they were submitted.
1~:00079
BACKGROUND OF THE INVENTION
This invention relates to a tool for stripping
the outer covering or sheath from a wire-containing cable
and more particularly to a tool having means for con-
trolling the depth of cut in the covering or sheath in
order to minimize damage to the insulated wires within
the cable.
Tools for removing the outer covering or sheath
from a wire-containing cable commonly consist of a shank
having a curved blade or hook for ma]cing a longitudinal
cut in the covering. A bead or protuberance is formed at
the free end of the blade for separating the covering from
the wires within the cable and for guiding the tool as it
is drawn along the cable. Examples of such tools are
illustrated in U.S. Patents No. 1,187,386 to Pehrson,
No. 4,145,808 to Walsh, No. 3,092,906 to Deering and East
German Patent No. 31,543 to Lose et al.
Before the tool can be used to make a longitudinal
cut in the covering, the covering must be severed circum-
ferentially so that the bead or protuberance can beinserted beneath the covering. The blade of the tool can
be used for this purpose, however, known tools frequently
lack effective means for preventing the blade from cutting
the insulated wires underlying the covering. If the
ins~ulation is inadvertently cut or nicked, the cable may
have to be discarded entirely to prevent injury or damage.
Known tools frequently also lack means for
ensuring that the depth of cut remains uniform as the tools
are drawn longitudinally along a cable. Lacking such means
the blade tends to skim over the peaks of the insulated
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wires within the covering and to dig into hollows
between the wires. The risk of damage to the insulation
is greater where the blade moves in this fashion than
where the blade makes a cut of uniform depth in the
covering.
SUMMARY OF THE INVENTION
It is, accordingly, an object of this invention
to provide a tool having means for controlling the depth
of cut in order to prevent inadvertent damage to insulated
wires beneath the outer covering or sheath.
Another object of the inevention is to provide
a tool having means for causing the blade to follow the
twist of wires within the covering as the tool is moved
parallel to the longitudinal axis of the cable to minimize
the tendency of the blade to skim over the peaks and dig
into hollows of insulated wires within the cable.
These and other objects are accomplished by a
tool for stripping the covering from a wire-containing
cable comprising a shank having a cutting edge for severing
the covering; a hook extending from the shank and having
an edge which faces an edge of the shank, both the edges
being sharpened for severing the covering. The hook is
S-shaped in order to ensure that the depth of cut is
uniform as the tool is drawn along the longitudinal axis
of the cable. A guide is moveably mounted to the shank for
adjusting the depth of cut made by the cutting edge in the
cover as the tool is drawn around the circumference of the
covering.
DESCRIPTION OF THE DRAWINGS
The invention is described in detail with
:
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reference to the accompanying drawings in which:
Figure 1 is an elevation of the tool of the
invention shown in conjunction with a wire-containing
cable;,
Figure 2 is a perspective view of the tool and
cable;
Figures 3 and 4 are enlarged perspective views
of the forward end of the shank of the tool;
Figure 5 is an elevation of the shank of the
tool from the handle side thereof;
Figure 6 is an elevation of the shank viewed in
the direction of arrows 6-6 in Figure 4;
Figure 7 is a plan view of the tool;. -_A
Figure 8 is a perspective view oE the`tool used
to cut the cable circumferentially; and
Figure 9 is a section of the cable and an
elevation of the tool viewed in the direction of arrows
9-9 in Figure 8.
Like reference characters refer to like parts
throughout the description of the drawings.
DESCR:IPTION OF THE PREFERRED EMBODIMENTS
With reference to Figure 1, the tool of the
invention indicated generally by the numeral 10 is shown
in conjunction with a cable 11. The tool is composed of a
handle 12, shank 14, a hook 16 and a guide 18. The hook
extends back towards the handle from the opposite end of
the shank and a protuberance or ball 20 is,l formed at the
outermost end of the hook. The inside edge 22 of the hook
which faces the shank is sharpened as is the facing edge 24
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of the shank. Both edges are sharpened to vertex 26.
With reference to Figure 3 ball 20 is connected
to a threaded shank 28 which is removably received in a
threaded bore in the free end of the hook 16. The illu-
strated ball can be replaced by balls of larger or
smaller diameter in order to adjust the depth of cut made
by the tool.
Guide 18 is composed of two limbs 30, 32 dis-
posed normal to each other. One limb 30 is disposed
parallel to the face 34 of the shank and has two slot-
shaped apertures 36, 38 for receipt of locking screws 40,
42. The forward end of the screws are threadably received
in apertures 44, 46 in the shank. The edge 48 of the
shank above the guide is sharpened to form a cutting edge.
With reference to Figures 4 and 7 cutting edge
24 is parallel to the longitudinal axis 70-70 of the shank
and both the axis and the cutting edge lie in an imaginary
plane marked 71. Hook 16 is generally S-shaped and has
one extent 72 which lies on one side of plane 71 and
another extent 74 which lies on the opposite side of the
plane. Ball 20 is intersected by the same plane.
An S-shape is the preferred configuration of
the hook but the hook may have other curved configurations
such as a C-shape. Whatever confi~uration is chosen, the
degree of curvature should preferrably be relatively small.
The curved shape has been found to facilitate the cutting
of the covering of the cable to a uniform depth as the
tool is drawn longitudinally in the manner illustrated in
Figure 2.
Guide 18 acts to limit the depth of cut by the
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cutting edge 48. The operation of the guide is described
with reference to Figures 4 to 6. Locking screws 40, 42
are first loosened and the guide is slid in the direction
of arrow 49 in Figure 5 until the distance between cutting
edge 48 and the surface of limb 32 which faces the cutting
edge, measured in a direc~ion normal to the plane of that
surface, is approximately the same as the thickness of the
covering of the cable. This distance is marked 50 in
Figure 6 and the thickness of the covering is marked 52 in
Figure 2.
The tool is then held as illustrated in Figure 9
such that the outstanding limb 32 of the guide contacts
the outer wall 53 of the covering and is disposed tangentally
of the cross section of the cable. The tool is then rotated
about the cable in order to cause the cutting edge 48 to
make a circumferential cut 60 in the covering. The guide
is pressed against the covering as the circumferential cut
is made thereby effectively severing the covering but not
penetrating beneath the covering and damaging the insulated
wires 64 therein.
After the circumferential cut is made, the
sharpened edges of the hook and shank are used to cut the
covering in a direction parallel to the longitudinal axis
of the cable. That operation is described with reference
to Figures 1 and 2. Hook 16 is first inserted through the
circumferential cut 60 into the space beneath the covering
and the tool is then drawn in a direction parallel to the
longitudinal axis of the cable. Ball 20 separates the
covering from the wires within the cable and guides the
tool in a spiral direction where the wires within the cable
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are twisted. As illustrated in Figure 2 the sharpened
edges 22, 24 of the hook and shank serve to sever the
covering as the tool is moved along the cable. The
covering can again be cut circumferentially at the end of
the longitudinal cut in order to remove the covering from
the cable.
It will be understood, of course, that modifi-
cations can be made in the preferred embodiments described
herein without departing from the scope and purview of the
invention as defined in the appended claims.
