The present invention relates to a manual cable stripping tool, the tool being of the type comprising an elongated body which extends along a longitudinal axis X-X and is provided with a recess delimiting a cable support head; a knife holder which is received in a sliding manner in relation to the body substantially along the longitudinal axis X-X and the free end of which is arranged in the recess, facing the support head; a cable sheath incision knife which is supported by the knife holder and the cutting portion of which is capable of extending beyond the free end of the knife holder; a biasing means which acts on the knife holder to displace it towards the support head; a gripping means which is rigidly connected to the knife holder for manoeuvring it; the knife holder being movable between an advanced position in which the incision knife is moved closer to the support head under the action of the biasing means and a retracted position in which the incision knife is moved away from the support head against the action of the biasing means.
In the field of industrial maintenance it is usual to act on cables covered with a sheath, in order to eliminate a portion of this sheath by a stripping operation. For this purpose, the operator manually positions the cable to be stripped between the support head of the tool and the incision knife, a spring being adapted to move the knife closer to the support and to clamp and secure the cable between these two members. The operator then acts on the tool with a rotary movement in relation to the cable and/or a translatory movement in relation to the axis of the cable in order to cut the sheath. The operator then removes the cut sheath manually.
It is known from U.S. Pat. No. 5,829,141 to use a tool to cut the outer layer of insulation from an elongated cable. The tool comprises a body rigidly connected to a cable support. A knife holder is mounted such that it can slide in relation to the body and supports an incision knife. A spring biases the knife holder towards the cable support. The knife holder is provided with a handle for displacing the knife holder and controlling its movements. The handle is dimensioned to be actuated by the index finger of the operator. However, the device does not facilitate rapid placement of the cable in the support.
DE 893 672 discloses a device for stripping a cable, comprising a hollow body in which a compression spring is accommodated, which spring acts on a knife holder which can slide axially in relation to the body. The knife holder comprises an incision knife adapted to cut the sheath of a cable which is secured by a clamp which is rigidly connected to the body. The longitudinal positioning of the clamp in relation to the body can be adjusted by means of a screw arranged in a channel and securing in the chosen position is achieved by means of a butterfly screw. However, placement of the cable between the knife and the clamp requires a plurality of actions by the operator, namely unscrewing the butterfly screw, opening the passage between the knife and the clamp, engaging the cable, closing this passage, compressing the cable between the knife and the clamp against the spring and re-screwing the butterfly screw while maintaining the pressure. These operations take a long time to implement.
According to one aspect, an object of the invention is to improve the design of the stripping tool by improving the placement of the cable in the support.
To this end, the invention relates to a tool of the above-mentioned type, the gripping means of which is arranged adjacent to the free end of the knife holder and comprises a bearing face adapted to receive the cable to be engaged in the support head.
The invention thus ensures rapid placement of the cable in the cable support, the tool also being ergonomic and simple to produce.
According to other features:
the bearing face is oriented in relation to the longitudinal axis X-X such that a force F applied to the cable in a direction substantially transverse to the sliding direction of the knife holder acts on the knife holder with an axial force component F1x capable of displacing the knife holder from its advanced position towards its retracted position against the action R of the biasing means;
the gripping means is arranged so as to project laterally, at least in part, from the support head, and in that the bearing face is inclined in relation to the longitudinal axis X-X of the body, laterally from the end of the knife holder towards the end of the body opposite the head, moving away from the longitudinal axis X-X;
the inclination is between 45° and 90°, preferably 65°;
the bearing face of the cable comprises a concave region for receiving the cable.
According to another aspect, an object of the invention is to improve the safety during an operation for stripping an electrical conductor. This problem is solved by the fact that, in a tool of the type indicated above, the tool comprises a retractable cutting blade, pivotally articulated to the casing of the body at the opposite end from the support head, the blade being movable between a rest position in which it is closed, retracted inside the body, and a working position in which it is open, completely extended from the body, and in that the casing of the body further comprises a channel which is transverse in relation to the axis X-X and intended to receive an electrical conductor, the cutting portion of the blade interfering in the profile of the channel in order to strip the conductor when the blade is in a virtually closed position.
The tool thus prevents risks of cutting the user and allows rapid circumferential cutting of the conductor, the tool also being ergonomic and simple to produce.
According to other features,
a member for opening the blade prevents the knife holder from sliding from the advanced position towards the retracted position when the blade is extracted at least in part from the body.
According to another aspect, an object of the invention is to make it easier to change the knife of the tool of the above-mentioned type. This problem is solved by the fact that, in a manual cable stripping tool of the above-mentioned type, the knife holder further receives a socket supporting the incision knife, and a clip arranged so as to be movable inside the socket, and in that the clip is provided with a locking/unlocking opening intended to interact with a groove of the end of the knife opposite the cutting portion of the knife.
The knife is thus kept locked in relation to the socket by means of a releasably securable clip which acts on the end of the knife opposite the cutting portion thereof.
More particularly, it is provided that
the knife holder receives the socket in a sliding manner substantially along the longitudinal axis X-X;
the knife holder receives a knob such that said knob can rotate relative to the knife holder, which knob is provided with an internal tapping which acts on an external thread of the socket in order to displace it in a sliding manner.
The invention and the advantages thereof will be better understood upon reading the following description which is given merely by way of example and with reference to the appended drawings, in which:
a to 5c are longitudinal sectional views of the tool from
a is a plan view of the clip of the knife sub-assembly from
b is a sectional view of the clip from
a is a sectional view in the direction of the arrows VIII in
b is a partial sectional view similar to
c is a partial perspective view along the line C-C in
The terms “lower”, “upper”, “right” and “left”, “top” and “bottom” used in the following description are understood according to the orientation of
The tool 1 comprises an elongated body 2 which extends along a longitudinal axis X-X and is provided with a recess 3 delimiting a support head 4 connected to a casing 5 forming a handle. A connecting portion 6 forms a constriction between the head 4 and the handle 5. A knife holder 7, on which a cable sheath incision knife 8 (
The body 2 is in the form of two shells 12a and 12b which are assembled by a screw 10. The shells are advantageously obtained by moulding a plastics material, respectively in one piece, which has the advantage of reducing the costs of production. Hook-shaped portions 14a and 14b form the support head 4 once they are assembled. The portions 14a and 14b respectively have a V-shaped inner form 16a and 16b which is capable of receiving a cable 90 (
The knife holder 7 of the tool is in the form of two other, L-shaped shells 20a and 20b which are assembled by appropriate means. They respectively comprise a lateral branch 22a and 22b, forming a projection 22 once the shells are assembled, and a longitudinal branch 23a and 23b, provided with an external rib 24a and 24b for sliding guidance along the axis X-X of a semi-circular inner housing 26a and 26b. The shells 20a and 20b respectively comprise an inner cavity 27a (
A biasing means 32 of high rigidity, in the form of a helical compression spring, moves the knife holder 7 towards and clamps it in relation to the support head 4. For this purpose, the spring 32 rests on one hand on the base of the housings 26a and 26b of the knife holder 7 and on the other hand on the internal stop of the shell 12b of the body 2. The knife holder 7 is thus continuously biased towards the support head 4.
The incision sub-assembly 30 basically comprises a socket 34 which is provided with an external thread 35 (
The tool also comprises at least one auxiliary cutting blade 40, pivotally articulated to a pin 42 rigidly connected to the body 2 at the opposite end from the support head 4, and a member 44 for opening the blade 40, articulated to another pin 46 rigidly connected to the body 2. The auxiliary blade 40 is used for cutting work more commonly performed by the user.
The blade 40 is movable in a retractable manner between a rest position in which it is closed, retracted inside the body 2 (
The main portion of the member 44 comprises a bore 48 capable of receiving the pin 46. The ends of the member 44 respectively comprise a first hook 50 and a second hook 52, the functions of which will be described below. A spring leaf 54 connected to the body 2 and to the member 44 resiliently biases the member 44.
In
The upper portion of the knife holder 7 comprises an upper free end 60, beyond which the cutting portion 9 of the knife 8 extends. The face of the end 60 is substantially perpendicular to the longitudinal axis X-X. The projection 22 extends from the face of the end 60 in the direction transverse to the longitudinal axis X-X of the body 2.
The projection 22 is arranged, at least in part, in the recess 3 of the body 2 and extends laterally leftwards beyond the body 2. Said projection comprises an upper bearing face 62 which is inclined in relation to the longitudinal axis X-X, laterally from the free end 60 towards the end of the body 2 opposite the head 4, moving away from the axis X-X. The angle of inclination a between the face 62 and the longitudinal axis X-X is between 45° and 90°, preferably 65°, such that the angle of inclination β between the faces 60 and 62 is between 135° and 180°, preferably 155°.
The projection 22 constitutes a gripping means which is rigidly connected to the knife holder 7 for manoeuvring it. This gripping means is arranged adjacent to the free end 60 of the knife holder 7. Depending on the grip of the operator, the inclined bearing face 62 of the projection 22 is easily accessible by the index finger or the thumb of the hand which holds the body 2. A concave region 64 of large radius is formed in the portion of the face 62 which permanently extends laterally beyond the body 2.
This arrangement improves the ergonomics of the grip of the index finger or thumb.
In addition, the concave region 64 of the bearing face 62 is particularly well adapted for receiving a cable 90 (
This has the advantage of providing the operator with a tool which is practical to use.
When the longitudinal branches 23a and 23b of the knife holder 7 are assembled, the knife holder 7 comprises, in the main portion thereof and on the lateral face thereof opposite the projection 22, a blind hole 70 adapted to receive the upper hook 50 of the member 44 for opening the auxiliary cutting blade 40.
While the blade 40 is at rest in the body 2, the lower hook 52 directed towards the pin 42 presses, under the action of the spring 54, on a substantially planar face 80 arranged at the end articulated at 42 of the blade 40. This firstly prevents any untimely opening of the blade 40 and secondly keeps the upper hook 50 directed towards the blind hole 70 with sufficient spacing from the hole 70 to allow the sliding of the knife holder 7 along the longitudinal axis X-X.
As soon as the blade 40 is partially displaced in rotation from the rest position, the inner hook 52 acts on a cam surface 82 which is adjacent to the flat portion 80 and arranged at the end articulated at 42 of the blade 40.
The completely open position of the blade 40 (
The shape of the cam surface 82 and the depth of the notch 84 are such that, under the rocking effect of the opening member 44, the upper hook 50 is engaged with the blind hole 70 when the blade 40 is extracted, at least in part, from the body 2 in the direction of the arrow d in
The knife holder 7 is thus prevented from sliding along the longitudinal axis X-X when the blade 40 is partly or completely extended from the body 2, and this provides safety for the operator.
a to 5c show the placement of a cable in the support head of the tool.
Before the placement of the cable, the body 2 being grasped with the whole hand, the operator adjusts the projection height of the knife 8 by actuating the knob 38 at the level of the windows 29a and 29b of the knife holder 7, between the thumb and the index finger of the hand holding the body 2 or between those of the other hand.
He then positions the cable 90 to be stripped on the free end of the inclined upper face 62 of the projection 22 while applying an increasing force F substantially perpendicular to the longitudinal axis X-X (
The cable 90 slides over the concave region 64, exerting on the knife holder 7 an increasing force F1 (
By substantially increasing the force F acting on the cable 90, the operator exceeds the friction forces of the edge of the head 4 acting on the cable 90. The component F1x becomes so great in relation to the reaction of the spring 32 that the knife holder 7 is displaced downwards, moving even further away from the head 4. The distance between the head 4 and the knife holder 7 is then sufficient for the cable 90 to fit and be wedged in the inner forms 16a and 16b in the shape of an upside down V of the head 4. The operator momentarily releases the force F on the cable 90 until it is cancelled, which has the result that the knife holder 7 is displaced upwards, moving closer to the head 4 in the direction of the arrow d2 under the effect of the axial reaction R of the spring 32 (
Since the knife holder 7 is continuously biased upwards, the incision knife 8 sinks into the sheath 91 (
In a known manner, the operator then performs the circular incision of the sheath 91, pushing the lower end of the body 2 leftwards in the direction of the arrow F2 in
Then, by turning his hand a quarter of a turn, the operator again grasps the body 2 with his whole hand and pulls it perpendicularly to the plane of
It should be noted that the knife 8 is mounted in a rotatable and eccentric manner in the knife holder 7, and this allows the cutting portion 9 to be oriented automatically either circumferentially or axially in relation to the cable 90 in the direction of the force exerted on the body 2.
The knife 8 comprises, in its main portion, an elongated cylindrical shaft 100 of outer diameter φ1 (
The socket 34 comprises a generally cylindrical barrel 103 which extends along the axis X′X′, delimited by a first face 104 directed towards the cutting portion 9 of the knife and a face 106 directed towards the clip 36. The socket 34 comprises two diametrically opposed flat portions 108 (only one is visible in
Since the thread 35 of the socket 34 corresponds to the tapping 39 of the knob 38, a rotary action on the knob 38 in relation to the axis X′-X′ causes a translatory movement of the socket 34. The user can thus preset the height of the cutting portion 9 of the knife 8 which projects from the face 60 of the knife holder 7.
The socket 34 also comprises a recess 110 (
The face 104 comprises a counterbore 120 (
In
In
The clip 36 is received in a sliding manner in the recess 110 in a direction perpendicular to the axis X′X′. The branch 130 is arranged in the first space 122 and comprises an opening 136 obtained by cutting (
The opening 136 in the branch 130 shown in
In terms of dimensions, the diameter φ3 is smaller than the diameter φ1 and larger than the diameter φ2, while the diameter φ4 is larger than the diameter φ1. In addition, the thickness e of the branch 130 is smaller than the width of the groove 102.
The end 101 of the shaft 100 of the incision knife is thus capable of passing through the second cut 146. When the groove 102 is engaged in the opening 136, the cuts 140 and 142 are adapted to slide in the groove 102 in a relative movement substantially perpendicular to the axis X′X′, a displacement along the axis X′X′ being limited to the play between the thickness e of the branch 130 and the width of the groove 102.
a shows the clip 36 in a stable position in which it is locked relative to the knife 8, which cannot be disassembled from the socket 34.
In this position the groove 102 is engaged in the cuts 140 and 142, as shown by dashed lines in
The shells 20a and 20b of the knife holder 7 respectively comprise a transverse passage 150a and 150b (
To obtain the position in which the knife 8 is locked in relation to the socket 34, the user firstly acts, from the outside, by turning the knob 38 so as to position the clip 36 along the longitudinal axis X′-X′, facing the passages 150a and 150b, the cutting portion of the knife 8 being virtually withdrawn inside the knife holder 7.
The user then acts on the free end of the branch 132 through the passage 150a formed in the shell 20a and arranged perpendicular to the axis X′-X′ by exerting a force in the direction of the arrow F3 in
Depending on the intensity of use of the tool, the cutting portion 9 of the knife 8 is subjected to wear over time.
To change the knife 8, the user again acts, from the outside, by turning the knob 38 so as to position the clip 36 longitudinally such that it faces the passages 150a and 150b.
He then urges the clip 36 from the locked position (
When the clip 36 is in the unlocked position, the boss 138 is disengaged from the blind bore 118 and the groove 102 is engaged in the curved cut 146 of large diameter, and this has the effect of allowing the uncoupling between the knife 8 and the clip 36 in an axial movement along the axis X′-X′.
It should be noted that, in the locked position, as in the unlocked position, the clip 36 is arranged entirely in the recess 110, without projecting in relation to the two flat portions 108.
The user displaces the knife holder 7 against the spring 32 and inverts the tool 1 by directing the support head 4 downwards in order to extract the knife 8 from the knife holder 7 under the effect of gravity.
A new incision knife 8 is mounted by way of the reverse operations.
The tool 1 has an additional stripping means adapted to a conductor of small diameter, such as an electric wire.
For this purpose, the casing 5 forming a handle comprises a channel 150 arranged perpendicular to the axis X-X of the body, the transverse profile of which channel, in the form of a partial circle, is adapted to receive a conductor 190 provided with a sheath 191 and shown by dashed lines in
The channel 150 is arranged on the outer envelope of the casing 5, close to the pin 42 of the retractable cutting blade 40, on either side of a slot 151 in the body 2, in which slot the blade 40 is positioned when it is retracted inside the body.
The arrangement of the channel 150 is such that the cutting or sharp portion 152 (
In an advantageous manner the outer envelope of the casing 5 also comprises a notch 160 which also extends perpendicular to the axis X-X on either side of the slot 151. The notch 160 is also arranged close to the pin 42 and its concave shape is provided with the channel 150.
The operator uses the notch 160 to grasp the blade 40 between thumb and index finger when said blade is in a retracted position inside the body 2. He can thus easily extract the blade 40 from the casing 5.
To strip the conductor 190, the operator extracts the blade 40 from the body 2, at least in part, allowing full access to the channel, for example in a completely extended position.
He then places the conductor 190 to be stripped in the channel 150 and positions the cutting edge 152 of the blade 40 in contact with the conductor by rotating the blade 40 in relation to the pin 42 in the direction of the arrow d3 in
The user keeps the conductor 190 clamped between the blade 40 and the channel 150 by exerting a pushing force in the direction of the arrow F5 in
He then causes one of the tool and the conductor to rotate in relation to the other along the axis of the channel 150 through an angle of approximately 180° in one direction and then in the other.
The sheath 191 of the conductor 190 is cut sufficiently over its circumference to expose the metal core of the conductor over the desired length.
The user thus benefits from a simple and effective arrangement for stripping a conductor of small diameter. This arrangement is applicable to a stripping tool at least provided with a body and a pivoting and retractable cutting blade, such as an electrician's knife.
Owing to the invention, the user can work effectively and quickly to strip a cable. He performs his tasks ergonomically and safely. In addition, he can change the incision knife rapidly without disassembling the tool completely. The tool also makes it possible to strip a conductor easily by means of a retractable cutting blade. Finally, the tool is simple, compact and economical to produce.
Number | Date | Country | Kind |
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12/01703 | Jun 2012 | FR | national |