GB2284945A - Tools for cutting and stripping cables - Google Patents

Abstract

A cable stripping tool, Figure 1, has a cruciform slot in one jaw 14 to receive a cable in either of two positions, and a circular saw-like cutter 34 is angularly fixed in position but spring (18, Figure 2) urged for movement towards the jaw so as to cut into the sheath of the cable irrespective of the extent of separation of jaw and cutter necessary to accommodate the cable diameter. When the cutter 34 becomes blunt the screw clamp 32 is released and the cutter rotated. The cutter may be moved laterally on its stem (30 figure 3) so as to cut to different depths into the cable insulation. <IMAGE>

Description

IMPROVEMENTS RELATING TO TOOLS FOR CUTTING AND STRIPPING CABLES This invention relates to tool for cutting and stripping cables.

U.S. Patent 3 169 315 shows a somewhat pliers-like tool for stripping cables in which one jaw has a groove extending in cruciform fashion and the other jaw carries a cutter. When the cable is placed in one of the grooves extending parallel to the pivot of the jaws, and the jaws are closed together, the cutter can penetrate the cable sheath and when the tool is rotated about the cable this makes a peripheral cut. When the cable is placed in the other groove, extending along the length of the jaws, and the jaws are closed together, the cutter again penetrates the cable sheath and can make an axial slit in the cable when there is relative movement between the tool and cable; and hence the sheath can be separated from the core and peeled off.

In one of the embodiments described in the said U.S.

patent, the cutter blade is adjustable in projection so as to be able to make cuts of different depth in the cable. In another embodiment a plurality of cutters project to different radial extents on a part which can be indexed by rotation so that anyone of those cutters can be in the operative position, and because they are all of different radial projections they can be used to make cuts of different depths.

However, whilst the tool of said U.S. patent can cope with insulations of different thickness by the mentioned arrangements it can only cope with cables of different diameter within a relatively narrow range.

The problem of dealing with cables of widely different diameter is solved in the arrangement shown in the EP 0 375 191. This recognizes that when the jaws are open to any extent, the cutter travels in an arc about the pivot between the jaw and cutter and this may take the cutting tip away from a line perpendicular to the grooved jaw and extending from the intersection of the two grooves. Said EP solves the problem by using the indexing means to return the cutter tip to the position needful when the jaws are open to the required extent, or making the complete cutter assembly slidable towards and away from the pivot to a similar, though not identical effect. However, tools according to the said EP have not been successful commercially, because they have been found difficult by users.

The object of the present invention is to solve the same problems as the mentioned EP, but in a new way so as to avoid the difficulties therein.

According to the present invention a tool for use in cutting and stripping of cable comprises a cutter pivoted for movement towards and away from a cruciform grooved jaw, and is characterised in that the cutter comprises a saw-like disc which is angularly fixed in position for a cutting operation.

Preferably the disc is angularly adjustable to interchange cutting surfaces when worn.

Circular disc-like cutters are well known, per se, in cable cutting and stripping tools, but are rotatable in use: the present invention is distinguished therefrom in the disc being fixed in use rather than rotatable, a well as in being of circular saw-like configuration and not truly circular. This is found particularly advantageous with many synthetic cable sheath materials which tend to compress rather than cut when contacted by a continuous blade but which are readily punctured by the spike-like teeth.

Due to the generally circular shape of the cutter of the invention, the extent of movement of the cutter awa from the cruciform grooves is immaterial and there will always be one or more teeth in a good cutting position.

Preferably the cutter is carried on an axially adjustable stem which gives rise to a further advantage in enabling a co-axial cable in a standardised position to have its successive sheaths cut and stripped to different positions along the axis of the cable.

In one presently preferred embodiment of the invention, shown in the drawing, in which Figure 1 is an elevation, with the tool closed; Figure 2 an end elevation with the tool open; and Figure 3 showing the cutter dissembled, a handle 10 is extended to provide a pivot 12 and then carry the cruciform jaw 14. A second lever 16 is pivoted on the handle and is spring l8-urged in the direction which carries the free end of the lever towards the cruciform groove. The lever is provided with a housing 20 in which a stem 30 extends in a direction transverse to the lever, and a screw clamp 32 is provided for fixing the axial and angular position of the spindle in that housing.

The spindle carries the cutter 34 at one end, and the cutter is between a pair of plain and relatively thick discs 36 clamping the cutter disc between them.

The cutter disc is of larger diameter than the plain discs so that a serrated peripheral edge of the cutter disc projects beyond the plain discs around their periphery. The spindle may have a series of grooves 40 spaced apart along its length for cooperation with the clamping screw so that the latter may fix the spindle angularly and also axially in any of a series of positions.

In the drawing the discs are located generally over the intersection of the cruciform grooves. The extent of radial projection of the cutter disc from the plain discs determines the depth of cut, so that for cables requiring cuts of widely varying depths, cutters and/or discs may be interchanged. However for many purposes a cut which is part-way through an insulation layer will be sufficient to enable the layer to be peeled off even though it is not through the complete thickness of the layer.

Whelp the tool is in use with relatively small diameter cables a particular one of the serrations may be located nearest to the groove and operative for cutting, whereas pivoting the lever so as to move the cutter away from the grooves brings adjacent serrations into use.

In order to make a first cut through the outermost sheath of a cable, the cable may be located in the groove shown in Figure 1 extending parallel to the lever pivot, the lever released to allow spring closing so as to take one or more of the serrations into contact with the sheath to puncture the sheath, and then the tool and cable are relatively rotated to make an encircling cut.

Thereafter the cable is placed in the other of the grooves seen in Fig 2 and the operation repeated except that it is a relative axial movement of the tool and cable to make one longitudinal cut, although a second one may be made if desired at a diametrically opposite point, enabling the cable sheath to be peeled off into separate strips.

If an inner layer is to be cut and stripped in like fashion but leaving a portion of the inner layer projecting relative to the outer layer, the axial position of the spindle may be adjusted before the peripheral cut is made but possibly returned to the original position for the longitudinal cut or cuts, although it is equally possible to adjust the cable to a different position in order to locate the cuts where required. It will be appreciated that with some cables there may be a plurality of layers to be stripped at different axial points, and the tool of the present invention is particularly convenient for this purpose.

From time to time, the clamping screw may be released and the cutter turned to present new serrations for use when some become blunted or worn.

Claims (5)

CLAliS

1. A tool for use in the cutting and stripping of cable comprising a cutter pivoted for movement towards and away from a cruciform grooved jaw, and characterised in that the cutter comprises a saw-like disc which is angularly fixed in position for a cutting operation.

2. A tool as claimed in Claim 1 comprising a handle carrying the cruciform grooved jaw, a lever pivoted on the handle and having a free end spring urged towards the jaw, a housing on said free end, a stem extending transversely of the lever and located in said housing, a screw clanp fixing the position of the stem, and said sa-lie disc being carried by the stem.

3. A tool as claimed in Claims 1 and 2 wherein the stem is axially adjustable.

4. A tool as claimed in Claims 1 and 2 wherein the stem is angularly adjustable.

5. A tool substantially as described with reference to the accompany drawings.