This invention relates to a cable stripping tool and, in particular although not exclusively, it relates to a cable stripping tool for preparing the end of an armoured cable for connection to other devices.
Armoured cables are commonly used to carry electrical power in harsh environments, such as underground. They typically include a plurality of conductor wires surrounded by armour to protect the conductor wires from inadvertent damage. A cross section through a typical armoured cable 1 is shown in
To prepare the cable 1 for connection to a device (not shown), a portion of the outer sheath 9 and the armour wires 8 are removed. A protective shroud and a first part of a gland are fed on to the cable 1. A further amount of the outer sheath is removed and the armour wires are thereby exposed and engage with a first part of the gland. A second part of the gland is then screwed on to the first part compressing the armour wires therebetween to secure the cable.
The cable is commonly prepared using a hack saw and a knife to make the relevant cuts. This is hazardous to the user and injury is common due to the degree of control required to saw and cut the cable. Furthermore, this method can lead to inaccurate cuts, particularly when employed by inexperienced or unskilled workers.
According to a first aspect of the invention there is provided a cable stripping tool comprising a body, a cable mounting portion and a blade assembly that is movable relative to the cable mounting portion between a retracted position and an engaging position, the blade assembly comprising a first blade and a second blade and wherein the second blade is movable relative to the first blade between an operable position and an inoperable position.
This tool is advantageous as it simplifies the cable stripping process and minimizes the risk of injury. The first and second blades can be used to make two circumferential cuts in the outer sheath and as the second blade is movable relative to the first it can be moved to an inoperable position while the first blade makes a deeper cut. Further, the movable blade assembly provices a retracted position in which assembly provides a retracted position in which it is easy for a user to place the tool around a cable to be prepared and an engaging position in which the cable is clamped into the tool.
The blade assembly may include a slide member that guides the blade assembly between the retracted position and the engaging position, the slide member including a slide assembly that controls the movement of the slide member. The slide assembly may comprise a screw threaded member. Controlled movement of the blade assembly may be effected by rotation of the screw threaded member. The slide assembly may include a ratchet mechanism.
This is advantageous as the screw threaded member can be arranged to provide a mechanical advantage to urge the first blade and second blade to cut the cable. The ratchet mechanism is advantageous as it can be disengaged to allow swift movement of the blade assembly between the retracted and engaging positions, while the screw threaded member provides precise control of the movement of the blade assembly. Thus, the tool can be clamped around the cable using the ratchet mechanism and then the advancement of the blade assembly to effect cutting can be provided by the screw threaded member.
The mounting portion may be arranged to receive the cable in a first orientation and a second orientation, and comprise means to permit rotation of the cable relative to the tool in both the first and second orientations. The first orientation may be 90° to the second orientation. The mounting portion is advantageous as it allows both circumferential cuts and axial cuts to be made in a cable.
In particular, the mounting portion may comprise a pair of rollers arranged parallel to one another, both rollers having a circumferential groove aligned with either the first or second blade. The groove in each of the rollers is advantageous as it provides a recess in which the cable can be received when in the second orientation.
Alternatively, the rollers may both include a circumferential ridge aligned with either the first or second blade. The ridge in each of the rollers 20 provides an abutment for the cable.
In an alternative embodiment of the invention, the pair of rollers may be substituted by a plurality, usually at least four, of resiliently mounted ball-bearings. The freedom with which a ball-bearing rotates about its central point is advantageous because it allows for a greater degree of flexibility when positioning the cable in the tool.
According to a second aspect of the invention, there is provided a cable stripping tool comprising a body, a cable mounting portion and a blade assembly that is movable relative to the cable mounting portion between a retracted position and an engaging position, the blade assembly comprising a first blade and a second blade and wherein the first blade is connected to the second blade such that, in use, the pressure applied by the second blade to a cable is lower than the pressure applied by the first blade.
According to a third aspect of the invention, there is provided a cable stripping tool, comprising a body, a cable mounting portion and a blade assembly that is movable relative to the cable mounting portion between a retracted position and an engaging position, the blade assembly comprising a first blade, the mounting portion being arranged to receive the cable in a first orientation and a second orientation, the cable mounting portion comprising means to permit rotation of the cable relative to the tool in both the first and second orientations.
Thus, a system is provided that may lack the second blade of the first aspect of the invention, but still allows the cable to be received in two different orientations. Accordingly, it is still possible to make the two different orientation cuts required without having to resort to a hacksaw. This would not be possible with prior art tube-cutting apparatus.
The first orientation is preferably substantially 90° to the second orientation. The mounting portion is advantageous as it allows both circumferential cuts and axial cuts to be made in a cable.
In particular, the mounting portion may comprise a pair of rollers arranged parallel to one another, both rollers having a circumferential groove aligned with either the first or second blade. The groove in each of the rollers is advantageous as it provides a recess in which the cable can be received when in the second orientation.
Alternatively, the rollers may both include a circumferential ridge aligned with either the first or second blade. The ridge in each of the rollers provides an abutment for the cable.
Alternatively, the pair of rollers may be substituted by resiliently mounted ball-bearings, such as those described in the first embodiment of the invention.
The cable stripping tool may be arranged such that, when a cable is placed across the rollers in the second position, there is no obstacle to the cable laying entirely straight perpendicularly to both rollers. In prior art tube cutting devices, the support for the blades would tend to block the cable being position in any other direction than along the rollers.
The cable stripping tool may have any of the optional features of the first aspect of the invention.
According to a fourth aspect of the invention there is provided a cable stripping tool comprising a body, a cable mounting portion and a blade assembly that is movable relative to the cable mounting portion between a retracted position and an engaging position, the blade assembly comprising a first blade, the mounting portion being arranged to receive the cable in a first orientation and a second orientation, and comprising means to permit rotation of the cable relative to the tool in both the first and second orientations wherein the blade assembly includes a slide member that guides the blade assembly between the retracted position and the engaging position, the slide member including a slide assembly that controls movement of the slide member and wherein the slide assembly includes a ratchet mechanism.
Preferably, the slide assembly further comprises a screw threaded member. More preferably, the screw threaded member and the ratchet mechanism are engageable, e.g. to locate the slide assembly in one or the other of the retracted and engaging positions. Even more preferably, engagement and/or disengagement of the screw thread member to and/or from the ratchet mechanism is controlled by an actuator. Preferably, the ratchet mechanism comprises a spring. More preferably, the spring is biased so that the slide member is urged toward the retracted position.
According to a fifth aspect of the invention there is provided a cable stripping tool having a body comprising an arm, a cable mounting portion and a blade assembly that is movable between a retracted position and an engaging position, the cable mounting portion comprising means having first and second cable mounting axes, wherein the arm extends from the cable mounting portion in a direction between the first and second mounting axes.
Preferably, the first cable mounting axis is substantially 90° to the second cable mounting axis.
Preferably, the arm extends from the mounting portion at approximately 45° from the first cable mounting axis.
Preferably, the arm is formed integrally with the mounting portion.
Preferably, a distal end of the arm supports the blade assembly.
Preferably, the arm is curved upwards with respect to the mounting portion.
Preferably, the blade is directly above the mounting portion. More preferably, the blade is directly above the point in which the first and second cable mounting axes intersect.
An advantage of the shape of the arm is that the cutting zone (i.e. the region in which the blade assembly reciprocates between the retracted and engaging positions) is not obstructed from view by any part of the body, in use, for example, when the cutting zone is viewed along any one of the cable mounting axes.
Preferably, blade assembly reciprocates linearly between the engaging and retracted positions. More preferably, the blade assembly is operable by control of a control member. The control member may be mounted to a screw threaded member.
Preferably, the blade assembly is operable to impart sufficient force on the blade to allow the blade to cut through the steel armour wire of an armoured cable.
The cable stripping tool may have any of the optional features of any the earlier aspects of the invention.
According to a sixth aspect of the invention there is provided a kit for connecting to a cable cutting device comprising a body, a cable mounting portion and a first blade support that is movable relative to the cable mounting portion between a retracted position and an engaging position, the kit comprising a second blade assembly adapted to connect to the first blade support such that it is movable with the first blade support between the retracted and engaging positions, wherein, when mounted to the first blade support, the second blade assembly and the first blade support provide two parallel blades, and in which, when the kit is mounted on the cable cutting device, the mounting portion is arranged to receive the cable in a first orientation and a second orientation, and comprise means to permit rotation of the cable relative to the tool in both the first and second orientations.
This is advantageous as a conventional cable stripping tool can be modified to include a second blade thereby making armoured cable preparation easy.
Preferably the kit includes an extension mount for connection to the mounting portion and adapted to provide a mount for a cable when the device is in use. The extension mount may comprise a set of rollers which extend, when mounted on the cable stripping tool, from the first
blade to the operable position of the second blade. The rollers may have a groove therein that lines up with one of the first blade or the second blade in its operable condition, when attached to the cable stripping tool.
The kit may comprise the cable stripping tool, or may be provided without it for fitting thereto.
The second blade assembly may comprise an attachment portion, a hinge and a second blade, wherein the second blade is movable relative to the
first blade support between an operable position and an inoperable position.
Alternatively, the positioning of the cable relative to the blade assembly may mean one of the blades is no longer in contact with the cable.
The second blade assembly may replace the blade of the cable cutting tool; in such a case the second blade assembly may also comprise a replacement first blade. Alternatively, the first blade of the cable cutting tool may be employed.
When attached to the cable cutting tool, the kit may form a cable cutting tool according to any of the preceding aspect of the invention.
There now follows by way of example only a detailed description of the present invention with reference to the accompanying drawings in which;
Referring to
The blade assembly 13 (as best seen in
The slide member 22 includes a slide assembly 23 for controlling the movement of the blade assembly 13 toward and away from the cable mounting portion 12. The slide assembly 23 includes a screw threaded member 23a mounted on the slide member 22 that engages a ratchet mechanism 22a (as shown in
The blade assembly 13 comprises an elongate housing member 26 having a first blade housing 27 at a first end 28 and a second blade housing 30 at its other end 31. The slide member 22 extends from the first end 28 of the blade assembly 13. The first blade housing 27 receives the first blade 20 and the second blade housing 28 receives the second blade 21. The blades 20, 21 are free to rotate in their respective housings 27, 28. The elongate housing member 26 includes a hinge 32 between the first and second housing portions 27 and 30. Thus, the second blade housing 30, and therefore the second blade 21, is moveable relative to the first blade housing 28. The hinged elongate housing member 26 allows the second blade 21 to move between an operable position (as shown in
In
In use, the slide member 22 is moved from the mounting portion 13 to its retracted position to allow the cable 1 to be placed on the rollers 14, 15 of the mounting portion 13. In particular, the cable I is placed in a first orientation with respect to the tool 10 such that the cable is parallel to the rollers 14, 15 and lies such that the cable 1 abuts both rollers 14, 15. The second blade 21 is locked in the operable position by the lock 33. The blade assembly 13 is then brought into contact with the cable 1 by pressing the control button 25 to disengage the ratchet mechanism. The slide member 22 can then be moved freely until the blade assembly 13 abuts the cable 1 and then the control button 25 is released to re-engage the ratchet mechanism. The blade assembly is now in the engaging position. The control knob 24 is then rotated to actuate the screw threaded member to urge the first blade 20 and second blade 21 to pierce the outer sheath 9. The slide member 22 and body 11 may be calibrated with a scale such that the depth that the blade assembly cuts into a cable can be determined.
The user rotates the control knob 24 until they feel a change in resistance caused by the first and second blades 20 and 21 contacting the armour wires 8. The tool 10 can then be rotated about the cable 1 to affect two circumferential cuts. Thus, the cable 10 will rotate on the first and second rollers 14, 15 while the first blade 20 and the second blade 21 will rotate in their respective housings 27 and 30 making two spaced cuts into the outer sheath 9. The first blade 20 makes a first circumferential cut represented by dotted line 35. The second blade simultaneously makes a second circumferential cut represented by dotted line 36. The control knob 24 may be rotated in combination with rotating the tool 10 around the cable 1. This allows the blade assembly to progressively cut deeper into the outer sheath 9 as the tool 10 rotates.
Once the first and second circumferential cuts 35, 36 have been made, the lock 33 can be disengaged to allow the second blade 21 to be moved from the operable position to the inoperable position. The lock 33 is then reengaged to hold the second blade 21 in the inoperable position. The control knob 24 is then rotated further such that the first blade 20 applies further pressure to the armour wires 8 to cut part way through them. As before, the tool 10 is rotated around the cable 1 such that the first blade 20 makes a complete circumferential cut at a depth to cut part way into the armour wires 8. Thus, the first circumferential cut 35 is made deeper.
The control button 25 can then be pressed to disengage the ratchet mechanism and allow the blade assembly 13 to be moved to the retracted position. The orientation of the tool 10 with respect to the cable 1 is then changed so that the cable 1 extends perpendicular to the rollers 14, 15, as shown in
The outer sheath 9 of the cable 1 between the first circumferential cut 35 and the end 41 can be removed. The outer sheath 9 of the cable 1 between the second circumferential cut 36 and the first circumferential cut 35 can also be removed. Further, as the first circumferential cut 35 was made part way through the armour wires 8, these can now be broken off by hand at the first circumferential cut 35. It is advantageous to ensure that the first circumferential cut 35 only extends part way through the armour wires 8 so that they can be removed by hand in a controlled manner. It will be appreciated by those skilled in the art that if the first circumferential cut 35 was made to a depth that extends through the armour wires 8 completely, then they would drop from the cable I when the outer sheath 9 was removed. This could be hazardous if working at height, for example.
In an alternative embodiment, as shown in
In an alternative embodiment, as described later, the second blade is omitted. The two circumferential cuts can instead be made by moving the cable along its length between using the first blade to make each cut. It is to be noted that the cable can be put into the position shown in
A cable stripping tool according to a third embodiment of present invention can also be provided as a kit of parts that may be attached to a suitable cable stripping (or tube cutting) tool.
A tube cutting tool 100, such as the “Large Tube Cutter” from Rothley Ltd of Wolverhampton, United Kingdom, is modified by the addition of the kit of parts forming this embodiment. The kit comprises a set of rollers 102, which attach to the lower part of the tube cutter, and replace the rollers that would otherwise be provided in the space 106 below the tube cutter's blade.
The kit also comprises a blade assembly 108, comprising first 110 and second 112 blades. This assembly replaces the blade that would otherwise be held in the blade support 114. It attaches to the blade support, so that it can be driven up and down with the blade support 114 relative to the body 104 of the tube cutter 100. The first 110 and second 112 blades are position parallel with each other.
When fitted to the tube cutter, the second blade 112 is positioned above a groove 116 in each of the rollers 102. This allows a cable to be positioned both laying between the rollers 102 along their length (the first position) and perpendicular to the rollers in the groove 116. The apparatus thus formed can then be used as described with respect to the first embodiment (
Referring now to
The rollers 206, 207 define two distinct orientations in which a cable may be mounted: a first mounting orientation which lies parallel too and in between the rollers 206, 207 and a second mounting orientation which lies orthogonal to the first mounting direction along the circumferential grooves 208 of the rollers 206, 207.
The arm 202 has a first arm end 202a and a second arm end 202b. The first arm end 202a is formed integrally with the mounting portion 203 and the second arm end 202b supports the movable blade assembly 205. The arm 202 upstands from the mounting portion 203 in a direction between the first and second mounting orientations and is curved such that the movable blade assembly 205 (and thus the blade 212) is positioned directly above the mounting portion 203. As will be appreciated, the curved shape of the arm 202 gives the user an unobstructed view of the cutting zone in either orientation. In other words the cutting zone is highly visible, in use, which increases accuracy of cutting, e.g. as a result of the user not having to alter his position when cutting. This is clearly shown when comparing the perspective views of the tool 200 in
Referring now to
A typical screw threaded member 213 is an M8 bar with left hand thread and standard pitch. Other threaded bars may be used.
The blade 212 is substantially the same as the blades already described in earlier embodiments of the invention and will not be discussed further.
The screw threaded member 213 is controlled by the control member 209. The control member 209 surrounds the actuating portion 210 and screw threaded member 213 and is secured in place by means of bolt 214. A washer 215 ensures that the slide assembly 204 remains intact. Rotation of the control member 209 in one direction causes the actuating portion 210 to move linearly in respect to the longitudinal axis of the screw threaded member 213. Thus, the actuating portion 210 urges the elongate housing member 211, and hence the blade 212, into an engaging position. Similarly, rotation of the control member 209 in the other direction causes the actuating portion 210 to move linearly in the opposite direction which draws the elongate housing member 211, and hence the blade 212, into a retracted position. In the engaging position, the blade 212 contacts a cable placed on the cable mounting portion 203 which therefore clamps the cable between the mounting portion 203 and the blade 212. In the retracted position the blade 212 is remote from the cable mounting portion 203 allowing a cable to be placed in the tool 200.
In use, the slide assembly 204 is moved from the cable mounting portion 203 to its retracted position to allow the cable Ito be placed on the rollers 206, 207 of the mounting portion 203. In particular, the cable 1 is placed in the first mounting orientation such that the cable is parallel to the rollers 206, 207 and lies such that the cable 1 abuts both rollers 206, 207. The moveable blade assembly 205 is then brought into contact with the cable 1 by rotating the control member 209 in one direction as described above. The user rotates the control member 209 until they feel a change in resistance caused by the blade 212 contacting the armour wires 8. The tool 200 can then be rotated about the cable 1 to effect a circumferential cut. The blade 212 is then moved to the retracted position as described above and the cable 1 can then either be moved longitudinally in the first mounting orientation a predetermined amount so that a second circumferential cut can be made, or the cable can be rotated 90° to the second mounting orientation so that a longitudinal cut can be effected.
Equally, the blade 212 may act upon the steel armour wires 8 in addition to the sheath 9.
In an alternative embodiment of the invention the rollers 204, 205 may be substituted by a plurality, e.g. four, of resiliently mounted ball-bearings, as shown in
In
Furthermore, it will be appreciated that tools 200, 300 having a single blade are more compact than tools having two blades. Tools having a single blade can therefore be operated by the user in a neater and more ergonomic fashion.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2009/002307 | 9/25/2009 | WO | 00 | 4/18/2012 |