Coaxial cable stripper

Abstract

A coaxial cable stripper, consisting of:--a cutting unit (1) comprising cutting means (7) for a plurality of sheaths, said cutting unit (1) being designed to surround a cable (5) and cut its sheaths simultaneously by rotation of said cutting means (7) about the cable (5),--an intermediate unit (2) designed to surround said cable (5) and comprising means (6, 29-31) for adjusting the rotation of said cutting means (7),--a fixing unit (3) comprising fixing means (8) for said cable (5), the three units (1-3) being adjacent to one another and aligned along a common axis defined by said cable (5).

Description

[0001] The present invention relates to a coaxial cable stripper. By coaxial cables is meant electric cables consisting of a plurality of concentric conductors mutually separated by sheaths. According to this definition, therefore, a triaxial cable, for example, must be deemed to belong to the family of coaxial cables and hence to be included amongst those cables which can be used with the stripper according to the invention.

[0002] The prior art contains different types of strippers for coaxial cables. In this regard may be cited those which are described in EP-A-397319, DE-A-11365, U.S. Pat. No. 4,987,801, U.S. Pat. No. 4,059,893, EP-A-140397, EP-A-81865 and EP-A-432957.

[0003] The strippers of the prior art suffer, however, from a certain number of drawbacks: the precision of the cut often leaves something to be desired. The complexity of the devices makes them fragile, this fragility has its origin in the fact that the cutting means are actuated or adjusted by springs, inevitably imprecise elements, which are placed in their vicinity. Moreover, for the majority of the devices, their large relative size does not allow them to be easily transported, for example in the pocket or bag of the user.

[0004] The present invention offers, in particular, the advantages of remedying the aforesaid problems. It relates to a coaxial cable stripper, consisting of:

[0005] a cutting unit comprising cutting means for a plurality of sheaths, said cutting unit being designed to surround a cable and cut its sheaths simultaneously by rotation of said cutting means about the cable,

[0006] an intermediate unit designed to surround said cable and comprising means for adjusting the rotation of said cutting means,

[0007] a fixing unit comprising fixing means for said cable,

[0008] the three units being adjacent to one another and aligned along a common axis defined by said cable, said stripper being characterized in that:

[0009] the cutting unit consists of a cylindrical housing which is open on that side of its base which is in contact with the intermediate unit, the inside of the housing consisting of at least:

[0010] a) two rotary cutting disks comprising an opening in their center for passage of the cable, the face of each rotary disk which is opposite the intermediate unit consisting of a swivel blade designed to cut the sheaths of the cable, the other face consisting of means for fixedly connecting with the adjacent disk and means for pivoting the blade,

[0011] b) a rotary guide disk comprising guide means for said blades, said guide disk being fixedly connected to the cutting disk which is adjacent thereto by means of said connecting means,

[0012] the back of the housing additionally consisting of driving means for the rotary cutting disk which is adjacent thereto;

[0013] the intermediate unit is fixedly connected to the fixing unit.

[0014] The absence of a spring at the level of the cutting means lends a certain robustness to the device, resulting in marginally greater cutting precision.

[0015] The device according to the invention can additionally have smaller dimensions, for example between 10 and 20 cm in length and a diameter between 5 and 10 cm.

[0016] According to one embodiment, the cutting disks comprise means which allow adjustment of the cutting depth.

[0017] In a variant of the invention, the guide disk consists of a cylinder which surrounds the cable and which comprises a set of slots serving as guides for the blades as they are pivoted.

[0018] In another variant, the guide disk itself comprises cutting means.

[0019] Preferably, the adjusting means of the intermediate unit consist of two disks, the first disk remaining fixedly connected to the assembly formed by the intermediate unit and the fixing unit, the second disk being designed to rotate about the cable whilst exerting a friction upon the first disk.

[0020] The different embodiments of the invention which are set out above can equally be used conjointly in one and the same device.

[0021] Of course, the stripper according to the invention may contain more than two cutting disks.

[0022] According to a preferred embodiment, three cutting disks are used and the guide disk is also provided with cutting means. This configuration is intended for the stripping of triaxial cables comprising four sheaths to be cut.

[0023] A detailed illustrative embodiment of the invention will be described below with reference to the following figures:

[0024] FIG. 1 represents a stripper according to the invention.

[0025] FIG. 2 shows essentially a disassembled cutting unit.

[0026] FIG. 3 represents a cutting disk, in front view, in a first configuration.

[0027] FIG. 4 shows the same disk as FIG. 3, but in another configuration.

[0028] FIG. 5 shows diagrammatically the disk of FIGS. 3 and 4 in rear view.

[0029] FIG. 6 illustrates a longitudinal section of the stripper of FIG. 1.

[0030] The stripper represented in FIGS. 1 to 6 is constituted by a cutting unit 1, an intermediate unit 2 and a fixing unit 3. It is designed to strip a triaxial cable. The inside of the stripper (see FIGS. 2 and 6) comprises a longitudinal channel intended to receive in removable fashion a coaxial cable 5. The cutting unit 1 consists of a cylindrically shaped housing 9, the external surface of which is provided with longitudinal serrations serving to facilitate the grasping and rotation of the cutting unit 1 by a user. The base 10 of the housing 9, located on the side of the intermediate unit 2, is open. The inside of the housing contains a disk 23 fixed to the back 22 of the housing 9 by screws 34, three cutting disks 11-13 and a guide disk 19.

[0031] The three cutting disks 11-13 are of identical structure, apart from their thickness, which can vary. In the example which is illustrated here, each disk has a different thickness. As will be seen later, the choice of thickness of the disks 11-13 determines the distance between two cutting zones. With particular reference to FIGS. 3 and 4, it will be noted that the face 15 of the disks 11-13 which is directed toward the back 22 of the housing 9 comprises a swivel blade 7 provided with a longitudinal slot 37. The position of its pivot 28 is such that the blade 7 can cut the sheaths of a cable 5 which passes through the opening 14 in the disk 11-13.

[0032] On the same face 15, the disk 11-13 additionally comprises two circular-arc-shaped slots 26, 27, the first slot 26 being disposed toward the periphery of the disk 11-13, the second 27 being located between the pivot 28 of the blade 7 and the central opening 14 in the disk. The disk also comprises two circular-arc shaped recesses 38, 39, the presence of which allows the total structure forming the stripper to be made lighter.

[0033] As can be seen in FIG. 5, the second face 16 of each disk 11-13 comprises two pivots 17, 18 disposed perpendicularly to the face 16 of the disk 11-13. The first pivot 18 is placed toward the periphery of the disk 11-13 and is designed to shift position inside the first slot 26 of the adjacent disk. The second pivot 17 is placed close to the central opening 14 and is designed to pass through the longitudinal slot 37 of the blade 7 of the adjacent disk and to shift position inside the second slot 27 of this same disk. The maximum displacement of the pivots 17, 18 in their respective slots 26, 27 is adjustable by virtue of a system consisting of a screw 25, the end of which can be inserted into the first slot 26.

[0034] The disk 23 fixed onto the back 22 of the housing 9, on its face directed toward the intermediate unit 2, also comprises pivots 17, 18, which are identical in their technical and functional characteristics to those of the other cutting disks (see FIG. 5).

[0035] The guide disk 19, apart from the zone adjoining its central opening, has a configuration similar to that of the first faces 15 of the cutting disks 11-13. The central part of the guide disk 19 consists of an extension in the shape of a cylinder 20, the external diameter of which is such that it can pass through the openings in the other disks 11-13, 23. The end of the cylinder 20 is situated toward the back of the housing 9 and extends slightly beyond this to terminate outside the housing 9. At the level of the fixed disk 23, the cylinder 20 comprises a circular groove 36 intended to receive in sliding fashion a screw 35 housed in the fixed disk 23. The presence of the circular groove 36 and of the sliding screw 35 ensures the retention of the set of disks 11-13, 19, and their movable contact with the fixed disk 23 and the housing 9 to which it is fixed. The cylinder 20 additionally comprises a series of slots 21 (see FIG. 2), which act as a guide for the blades 7.

[0036] The intermediate unit 2 consists of a cylindrical sleeve 29 fixedly connected to the cylinder 20 of the guide disk 19, a rotary disk 30 fixedly connected to the sleeve 29 by screws 32, and a fixed disk 31 exerting a friction upon the rotary disk 30 via springs 6, which surround screws 24 disposed perpendicularly to the two disks 30, 31.

[0037] The fixing unit 3 is fixedly connected to the intermediate unit 2 by means of screws 33.

[0038] It consists of a system of clamps 8, which prevent the rotation and translation of the cable 5 when this is placed in the stripper, the fixing of the cable 5 being realized by screwing the outer casing of the fixing unit 3 in the direction of the intermediate unit 2.

[0039] The stripper which has previously been described operates as follows:

[0040] Prior to the introduction of the cable 5, the cutting depth of each blade 7 is defined by adjusting the depth of the adjusting screw 25 of the first slot 26 of the cutting disks 11-13. The friction force between the rotary disk 30 and the fixed disk 31 of the intermediate unit is adjusted by action upon the screws 24 present inside the springs 6.

[0041] The different elements are then assembled. With one of his hands, the user effects a rotation of the housing 9 of the cutting unit 1 in the clockwise direction, the other hand preferably grasping the fixing unit 3. This gesture produces a displacement in the same direction of the pivots 17 passing through the blades 7. The latter are then distant from the central opening 14 in the cutting disks 11-13, 19. The cable can thus be introduced into the stripper, preferably on the side of the fixing unit 3. The cable 5 is next fixed in the fixing unit 3. In this configuration, the stripper is ready for the cutting of the sheaths. The user effects a rotation of the housing 9 of the cutting unit 1 in the counter-clockwise direction. The blades converge and penetrate into the different sheaths at previously defined depths.

[0042] It will here be noted that the speed of rotation of the blades 7 about the cables, as well as the quality of the cut, are determined by the adjustment of the screws 24 which, through the use of springs 6, alter the friction between the rotary disk 30 and the fixed disk 31 of the intermediate unit 2. The speed of rotation of the blades will be all the higher, and the cutting quality diminished, if the friction between the two disks 30, 31 is weak.

[0043] Although it is theoretically possible to effect a single rotation of the housing 9 to cut the sheaths, the user must carry out a few rotations in order to ensure that complete cuts have been made.

[0044] At the end of these rotations, the user firstly frees the cable 5 at the level of the fixing unit 3, he then applies a traction to the cable, preferably from the side of the stripper where the fixing unit 3 is found. The cable 5 is thus able to depart the stripper and the cut-off sheaths remain temporarily inside the stripper before being removed, in turn, by shaking of the stripper and rotation of the housing 9 in the clockwise direction so as to release the blades from the central opening 14 in the cutting disks 11-13, 19.

[0045] Self-evidently, the invention is not limited to the example described above. The number of cutting disks is not, of course, limited to four.

[0046] As a non-illustrated option for determining the distance between the cutting zones, the presence of circular rings between the cutting disks can also be envisaged, the thickness and/or number of these rings allowing an adjustment of the distance between the cutting zones.

[0047] It is finally worth pointing out that the blades used within the framework of the present invention can be standard, which makes the subject of the invention relatively economical.

Claims

1. A coaxial cable stripper, consisting of: a cutting unit (1) comprising cutting means (7) for a plurality of sheaths, said cutting unit (1) being designed to surround a cable (5) and cut its sheaths simultaneously by rotation of said cutting means (7) about the cable (5), an intermediate unit (2) designed to surround said cable (5) and comprising means (6, 24, 29-32) of adjusting the rotation of said cutting means (7), a fixing unit (3) comprising fixing means (8) for said cable (5), the three units (1-3) being adjacent to one another and aligned along a common axis defined by said cable said stripper being characterized in that: the cutting unit (1) consists of a cylindrical housing (9) which is open on that side of its base (10) which is in contact with the intermediate unit (2), the inside of the housing (9) consisting of at least: a) two rotary cutting disks (11-13) comprising an opening (14) in their center for passage of the cable (5), the face (15) of each rotary disk (11-13) which is opposite the intermediate unit (2) consisting of a swivel blade (7) designed to cut the sheaths of the cable (5), the other face (16) consisting of means (18) for fixedly connecting with the adjacent disk (11-13, 19) and means (17) for pivoting the blade (7), b) a rotary guide disk (19) comprising guide means (20, 21) for said blades (7), said guide disk (19) being fixedly connected to the cutting disk (11) which is adjacent thereto by means of said connecting means (18), the back of the housing (22) additionally consisting of driving means (18) for the rotary cutting disk (13) which is adjacent thereto; the intermediate unit (2) being fixedly connected to the fixing unit (3).

2. The stripper as claimed in the preceding claim, characterized in that that side (15) of a rotary cutting disk (11-13) which consists of the swivel blade (7) also consists of means (25) for adjusting the positioning of the connecting means (18) located on the face (16) of the adjacent disk, this in order to allow an adjustment of the cutting depth of the blades (7).

3. The stripper as claimed in claim 1 or 2, characterized in that the rotary guide disk (19) comprises a cylinder (20) intended to surround the cable (21), said cylinder (20) comprising a series of slots (21) which are disposed perpendicularly to the direction defined by the cable (5) and are designed to guide the blades (7) as they are pivoted.

4. The stripper as claimed in any one of the preceding claims, characterized in that said connecting means (18) and said means (7) for pivoting the blade are pivots disposed perpendicularly to the faces (15, 16) of the disks (11-13), the connecting pivot (18) entering into contact with a first circular-arc-shaped slot (26) made on the face (15) of the opposite disk, the pivot (17) acting on the blade (7) entering into contact with a second circular-arc-shaped slot (27) made on a part of the blade (7).

5. The stripper as claimed in any one of the preceding claims, characterized in that the guide disk (19) also comprises cutting means (7).

6. The stripper as claimed in any one of the preceding claims, characterized in that the adjusting means (6, 29-31) of the intermediate unit (2) consist of two disks (30, 31), the first disk (31) remaining fixedly connected to the assembly formed by the intermediate unit (2) and the fixing unit (3), the second disk (30) being designed to rotate about the cable (5) whilst exerting friction upon the first disk (31).

7. Method of use of a stripper according to any one of the claims, characterized in that a rotation in one direction of the cutting unit (1) results in the blade (7) being moved toward the sheath to be cut and in that an oppositely directed rotation results in the blade (7) being moved further away from the sheath.