MXPA06012947A

MXPA06012947A - Device for inspecting stripped conductors.

Info

Publication number: MXPA06012947A
Application number: MXPA06012947A
Authority: MX
Inventors: Hatsuo Yamada; Noriaki Kakinami
Original assignee: Japan Automatic Machine Co Ltd
Priority date: 2005-11-10
Filing date: 2006-11-08
Publication date: 2007-05-09
Also published as: CN1976149B; CN1976149A; JP2007132812A; JP4699179B2

Abstract

Described is a device for inspecting stripped or peeled conductors so as to detect stripped conductors in wires by a laser beam irradiation in order to detect wheatear a metallic cord or filament, included in the conductor, is lost or not. The laser beams are vertically directed, and obliquely forwardly and backwardly directed, at an angle from about 37.5 degrees to about 52.5 degrees with respect to the vertical laser beam, provided that a stripped or peeled conductor includes a central metallic cord or six metallic cords arranged about the central metallic cord at equal angular intervals.

Description

DEVICE FOR INSPECTING DISPURED DRIVERS BACKGROUND OF THE INVENTION Field of the invention The invention relates to an apparatus for inspecting stripped or stripped conductors, for inspecting a stripped conduit, exposed when stripping one end of the insulator of an electric cable. More specifically, the present invention relates to inspection techniques for inspecting an exposed conductor of an electric cable in terms of the loss of wires when irradiating the exposed conductor with a laser beam. Description of the Related Art A cable stripper is widely used to generate a stripped conductor by removing an end portion of the insulator from an electrical cable and to attach a terminal to the stripped conductor. As mentioned in JP-A 6-225423 and Japanese Patent No. 2651305, a device for inspection of stripped electrical cables is used in combination with the stripping-overflow in some cases. The device for inspecting stripped electrical cables inspects an exposed stripped conductor by removing an end portion of the insulator from an electric wire to see if the end portion of the insulator has been properly removed.

The construction of the apparatus for inspecting stripped electric cables, for inspecting a stripped conductor, exposed by removing an end portion of the insulator of an electric cable mentioned in JP-A 6-225423 will generally be described with reference to Fig. 16. The device to inspect stripped electrical cables, inspect an electrical cable 1 to observe if the stripping work of the insulator to remove an extreme part of the insulator of the electric cable 1 to expose a stripped conductor 2, has been properly fulfilled, by irradiating the stripped conductor 2 with a laser beam. When the conductor 2 of the electric cable 1 moves in the direction of the arrow shown in Fig. 16 through the laser beam, the luminous flux of the laser beam passing through an aperture 6 formed in a surface is reduced. light receiver of a photodetector 4. Fig. 17 shows the variation with time, provided by the photodetector, of the voltage of a detection signal corresponding to the luminous flux of the laser beam passing through the aperture 6. A region 1 is a period before the stripped conductor 2 begins to cross the laser beam. A region 2 is a period immediately after the driver 2 has begun to cross the laser beam. A region 3 is a period in which the conductor 2 moves through the laser beam. The device for inspecting stripped electric cables, shown in Fig. 16, decides that stripping work has been satisfactorily accomplished when a detected voltage V is still for a determined time in a region between a reference voltage greater than VH and in reference voltage. lower VL. When a striker provided with opposing stripping or stripping edges is used to remove an end portion of the insulator from the electric cable 1, to expose the conductor 2, the end portion of the insulator of the electric cable 1 may be stripped in one of several states shown in FIG. Figs. 18 (a) to 18 (e). Fig. 18 (a) shows a satisfactorily stripped conductor 2, exposed by properly stripping an end portion of the insulator of an electric cable 1. Fig. 18 (a) shows an electric cable that has a part the end of the insulator not removed. Fig. 18 (c) shows an electric cable from which an end portion of the conductor 2 has been cut. Fig. 18 (d) shows a conductor 2 stripped from an electric cable, in which lower threads 2b have been lost of conductor 2 and only the upper strands 2a of the stripped conductor remain intact. Therefore, it is required that a device for inspecting stripped electrical cables, for inspecting an electrical cable as to the results of stripping work of the insulator, has a function to inspect the stripped conductor 2 for the loss of the wires., in addition to a function to determif part of the insulation has been removed or not. In general, the electrical cable to be inspected has a conductor that includes seven to neen wires helically wound around a central wire. A conductor 2 of an electric cable 1 shown in FIG. 19 (a), by way of example, is formed by arranging six wires at angular intervals of 60 degrees, around a central wire. The device for inspecting stripped electrical cables, shown in Fig. 16, irradiates the conductor with a single laser beam traveling along an optical axis. Assume that the width of a part of the laser beam obscured by conductor 2 is a shadow width. The shadow width does not change, even if the lower threads 2b, 2b 'and 2d are lost, as shown in Fig. 19 (b), or even if the threads 2a, 2a' and 2c are lost, as shown in Fig. 19 (c). Assume that the threads are arranged in angular positions as shown in Fig. 20 (a). The width of the shadow does not change, even if the threads 2b 'and 2d are lost, as shown in Fig. 20 (b) or even if the upper threads 2a and 2c are lost, as shown in Fig. 20 (c). Therefore, it is known that the apparatus for inspecting stripped electric cables, shown in Fig. 16, can determwhether part of the insulation end has been removed or not, but can not determwhether the threads have been lost or not. The apparatus for inspecting stripped electric cables, shown in Fig. 16, determ whether the end part of the insulator has been removed or not, based on the relationship between the detected voltage VD and the reference voltages VH and VL, and therefore, it is necessary to establish in advance the higher reference voltage VH and the lower reference voltage VL. Since the width of the shadow is dependent on the angular positions of the wires, the stripped conductors of many electrical cables need to be inspected to determa criterion. If the lenses and filters included in the light emitting device 3 and the light receiving device 4 of the apparatus for inspecting stripped electrical wires shown in FIG. 16 are contaminated with dust, the intensity of the light emitted by the light source is reduced. light emitting device 3 and the one receiving the light receiving device 4. As a result, the detected VD voltage is reduced. The apparatus for inspecting stripped electrical cables, shown in Fig. 16 uses a single laser beam traveling along an optical axis. Therefore, the apparatus for inspecting stripped electric cables has difficulty in determining which of a change in the width of the shadow and the reduction in intensity in the laser beam has caused the reduction of the detected voltage VD and requires cumbersome work for the inspection and maintenance of the light emitting device 3 and the light receiving device 4. BRIEF DESCRIPTION OF THE INVENTION Accordingly, an object of the present invention is to solve the above problems in related techniques and to provide an apparatus for inspecting stripped conductors that can reliably inspect a stripped conductor of an exposed electrical cable by stripping a part Extreme insulation of the electric cable in terms of the loss of the wires, to easily establish a criterion and to reduce the work for inspection and maintenance tasks. An apparatus for inspecting stripped conductors according to the present invention, for inspecting a stripped conductor of an electric cable, exposed by stripping an end portion of an insulator included in the electric cable by irradiating the conductor stripped with laser beams, said apparatus for inspecting stripped conductors includes: means projecting the laser beam, capable of projecting laser beams on the stripped conductor of the extended electric cable in a first horizontal direction and moving in a second direction perpendicular to the first horizontal direction respectively in a vertical direction, a forward direction obliquely with respect to the second horizontal direction and a backward oblique direction with respect to the second horizontal direction; means receiving the laser beam, capable of receiving the laser beams projected by the means projecting the laser beam, and of providing signals of the measured voltages, proportional to the light fluxes of the received laser beams; and decision means for deciding whether the stripped conductor is intact or not, based on the criterion or the measured voltages of the signals provided by the means receiving the laser beam and representing the light fluxes of the received laser beams. The axes of the laser beams projected by the means projecting the laser beams can be contained in a vertical plane parallel to the second horizontal direction, they can be contained in vertical planes parallel to the second direction and arranged at intervals in the first direction horizontal or can cross the axes of the electric cable in different positions, respectively, with respect to the second horizontal direction. In the apparatus inspecting stripped conductors according to the present invention, one of the three laser beams can be projected onto the stripped conductor from a position directly above the stripped conductor, and the other two laser beams can be projected down obliquely. on the stripped conductor, from a position in front of stripped conductor and a position behind the stripped conductor, respectively, or they may project upward obliquely from a stripped front conductor position and a position behind the stripped conductor, respectively. In the apparatus inspecting stripped conductors according to the present invention, the laser beams can be projected forward obliquely or obliquely backward. The apparatus inspecting stripped conductors in accordance with the present invention inspects the stripped conductor of the electric cable by irradiating the stripped conductor with the laser beams having axes extending in different directions, respectively. The width of the shadow of one of the laser beams decreases if one or some of the threads of the stripped conductor are lost. Therefore, the loss of one or some of the threads can be detected by examining the widths of the shadows. Therefore, a reliable decision can be made as to whether the stripped conductor is intact or not, through inspection of the stripped conductor by the stripping conductor inspecting apparatus of the present invention. In the apparatus inspecting stripped conductors according to the present invention, it is preferable that the means projecting laser beams project one of the laser beams vertically and the other two laser beams obliquely forward and obliquely backward at equal angles, respectively, with respect to the laser beam in a vertical plane perpendicular to the first horizontal direction. Therefore the respective axes of the two laser beams projected obliquely forwardly and obliquely towards each other, respectively, are symmetrical with respect to the axis of the vertical laser beam. Therefore, the loss of any of the threads of the stripped conductor can be found reliably by arranging the means projecting the laser beams at an optimum angular position, determined based on the sectional shape of the stripped conductor when the threads of the stripped conductor they are arranged symmetrically with respect to an axis parallel to the second horizontal direction. In the apparatus inspecting stripped conductors according to the present invention, it is preferable that the means projecting the laser beams include a first means projecting the laser beam, arranged to project the laser beam obliquely at a first angle with the laser beam. vertical laser beam in a vertical plane perpendicular to the first horizontal direction, and a second means projecting a laser beam arranged to project the laser beam obliquely at a second angle with the vertical laser beam in a vertical perpendicular plane with the first horizontal direction. The means projecting the laser beams may include first to fourth means projecting the laser beams arranged to project the laser beams obliquely at first to fourth angles different from each other, respectively, with the vertical laser beam, at place of the first and second means that project the laser beams. The means projecting the laser beams may include, in combination, two first means projecting laser beams arranged in the second horizontal direction symmetrically with respect to the vertical laser beam, and two means projecting laser beams arranged in the second direction horizontal symmetrically with respect to the vertical laser beam. The means projecting the laser beams may include, in combination, two second means projecting the laser beams arranged in the second horizontal direction, symmetrically with respect to the axis of the vertical laser beam, and a second means projecting a beam of laser arranged in front of or behind the axis of the vertical laser beam. The apparatus inspecting stripped conductors according to the present invention uses a plurality of laser beams projected obliquely at different angles relative to the vertical laser beam, for the inspection of the stripped conductor. Therefore, the probability of a successful detection of the reduction of the width with one of the plurality of laser beams, due to the loss of one or some of the wires of the stripped conductor can be further improved. A more reliable inspection of the stripped conductor can be achieved with regard to lost strands.

The stripped conductor to be inspected by the apparatus inspecting stripped conductors according to the present invention has a central wire and six wires disposed around the central wire at identical angular intervals. In the apparatus inspecting stripped conductors according to the present invention, it is preferable that the means projecting the laser beams project the laser beams obliquely forwardly and obliquely backwards, respectively, at an angle between 37.5 degrees and 52.5 degrees with relation to the vertical laser beam, in a vertical plane perpendicular to the first horizontal direction. When the means projecting the laser beams are arranged in such a way that the oblique laser beams project at angles between 37.5 degrees and 52.5 degrees, preferably at 45 degrees, relative to the vertical laser beam, to inspect the driver stripping of the electric cable that has six wires arranged at identical angular intervals, the possibility of failure can be reduced to its minimum extension by detecting the loss of the threads of the stripped conductor, lying on the axes of each laser beam. Therefore, the stripped conductor can be reliably inspected for the loss of threads.

Preferably, the device inspecting stripped conductors according to the present invention also includes a means that emits a laser beam to emit a laser beam, and a means that divides the beam from the laser beam to split the laser beam emitted by the laser beam. the medium that emits the laser beam, in equal parts, in laser beams and that distributes the laser beams to the means projected by the laser beams. In the apparatus inspecting stripped conductors according to the present invention, the means projecting the laser beams can project the laser beams of the same intensity onto the stripped conductor. Therefore, the decision means can easily decide which of the means receiving the laser beams is abnormal when the levels of the signal are abnormal, of the detection signals provided by the means receiving the laser beams. Therefore, precise adjustment tasks can be performed to adjust the means received by the laser beams, to make the signal levels of the detection signals provided by the means receiving the laser beams equal to each other and to It can improve the accuracy of inspection of stripped conductors.

Preferably, the apparatus inspecting stripped conductors according to the present invention further includes correction means for correcting the luminous flux levels corresponding to the measured voltages of the signals provided by the means receiving the laser beams, and a control means. of corrections to individually control the operation of the correction means. The correction control means controls the correction means in such a way that the luminous flux levels corresponding to the voltages measured after the corrections made by the correction means are equal to each other in a state where the laser beams are not intercepted by the stripped driver. A correction operation to match the luminous flux levels corresponding to the measured voltages with each other can adjust the luminous flux levels to a predetermined level of the luminous flux or can correct the luminous flux levels of other detection signals that deviate from the luminous flux. those of the luminous flux levels of the detection signals. A correction operation for correcting a luminous flux level corresponding to the measured voltage can be carried out automatically and continuously in the intervals between the driver's inspection operations. If one of the means receiving the laser beams of the apparatus inspecting stripped conductors according to the present invention is contaminated with powder and the level of luminous flux represented by the measured voltage provided by the means receiving the laser beams is reduced., the level of the luminous flux can be corrected to match that represented by the measured voltages provided by the other means receiving the laser beams. Therefore, high accuracy of the inspection of the stripped conductor can be maintained. In addition, maintenance tasks can be omitted to clean the lenses and filters of the media projecting the laser beams and the media that receives the dust-contaminated laser beams and the inspection tasks to inspect the slow and dirty filters. the means that project the laser beams and the means that receive the laser beams, or the work necessary for such tasks can be reduced. Preferably, the apparatus inspecting stripped conductors according to the present invention further includes means for detecting a maximum and minimum luminous flux, for detecting the maximum and minimum luminous fluxes between the luminous fluxes represented by the measured voltages provided by the means receiving the luminous fluxes. laser beams at a predetermined time, when a satisfactorily stripped conductor is inspected, means establishing a criterion for establishing a luminous flux of upper limit calculated by adding "a" percent of the maximum luminous flux with the maximum luminous flux and a luminous flux lower limit calculated by subtracting "b" percent from the minimum luminous flux of the minimum luminous flux as a criterion, and decision means which decide that the stripped conductor is intact when the luminous fluxes represented by the measured voltages provided by the receiving means the laser beams during the i The stripped conductor's inspection is within an acceptable region of the luminous flux, between the upper limit luminous flux and the lower limit luminous flux. The values "a" percent and "b" percent may be different from one another or they may be each other.The apparatus inspecting stripped conductors measures a maximum diameter and a minimum diameter of a conductor satisfactorily stripped and uses the flow region acceptable luminous flux between the luminous flux of the upper limit calculated by adding "a" percent of the maximum luminous flux to the maximum luminous flux and the luminous flux of the lower limit calculated by subtracting "% of the minimum luminous flux from the minimum luminous flux, as a criterion.

Therefore, the stripped conductor can be inspected even if the maximum diameter of the stripped conductor is increased and the minimum diameter of the stripped conductor is reduced when the stripped conductor is flattened by straightening work to straighten the stripped conductors that have been bent. Preferably, the apparatus inspecting stripped conductors according to the present invention further includes input means of a reference level to provide the values of a "percent and xb" percent as the reference levels for the means establishing the criterion. The values of a percent and "b" percent can be increased or reduced individually or can be increased or reduced equally. The apparatus inspecting stripped conductors according to the present invention can determine an optimum criterion by adjusting the region of allowable luminous flux according to the size and shape of a stripped conductor to be inspected or at the level of straightening of the bends, in the apparatus inspecting stripped conductors according to the present invention, the means detecting the maximum and minimum luminous fluxes begin to detect the maximum and minimum luminous fluxes after the decrease below a predetermined luminous flux of the luminous flux represented by the measured voltage provided by the means that receive the laser beams. Therefore, the apparatus inspecting stripped conductors according to the present invention detects the sudden drop of the luminous flux represented by the measured voltage, which occurs after the interception of the laser beam by the stripped conductor and begins to detect the luminous flux. maximum and minimum after the reduction of the luminous flux below the predetermined luminous flux. Therefore, the apparatus inspecting stripped conductors does not need additional devices such as a sensor that detects the movement of the electric cable and a means that provides the start instruction for the measurements, and therefore the apparatus inspecting stripped conductors has a configuration simple. An apparatus inspecting stripped conductors according to the present invention includes a first apparatus inspecting stripped conductors according to the present invention and a second apparatus inspecting stripped conductors according to the present invention, arranged in a direction of transport of the electric cable , wherein the first apparatus inspecting stripped conductors uses a vertical laser beam and two oblique laser beams inclined in opposite directions, respectively, at 45 degrees with respect to the vertical laser beam and the second apparatus inspecting stripped conductors uses a beam vertical laser and two oblique laser beams inclined in opposite directions, respectively, at 67.5 degrees relative to the vertical laser beam. Therefore, the first and second apparatus inspecting stripped conductors of the system inspecting stripped conductors use oblique laser beams inclined at different angles, respectively, relative to the vertical laser beam. Therefore, even if the first device inspecting stripped conductors can not find the broken wires, the second device that inspects stripped conductors can find the broken wires. Therefore, the system that inspects stripped conductors can inspect the stripped conductors in terms of breaking one of the threads. As apparent from the above description, the apparatus inspecting stripped conductors in accordance with the present invention can reliably inspect stripped conductors for yarn loss, can easily establish the criteria and can reduce the work required for inspection and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which: Figs. 1 (a) and l (b) are a front elevation, and a lateral elevation respectively, of an apparatus inspecting stripped conductors in a first embodiment according to the present invention; Fig. 2 is a block diagram of the apparatus inspecting stripped conductors, shown in Fig. 1; Fig. 3 is a graph of help explaining the variation of the levels of the detection signals provided when inspecting stripped conductors satisfactorily and a method establishing a region of permissible luminous flux; Fig. 4 is a flow chart of a method for correcting the luminous flux level; Fig. 5 is a flowchart of a procedure for establishing the permissible luminous flux region; Fig. 6 is a flowchart of an inspection procedure for stripped conductors; Fig. 7 is a graph showing the variation of light flows during the inspection of a stripped conductor; 'Figs. 8 (a) and 8 (b) are schematic views showing the relationship between the travel directions of the laser beams and the angular position of a stripped conductor; Figs. 9 (a) and 9 (b) are schematic views showing the relationship between the travel directions of the laser beams and the angular position of a stripped conductor; Figs. 10 (a) and 10 (b) are schematic views showing the relationship between the travel directions of the laser beams and the angular position of a stripped conductor; FIGs. 11 (a) and 11 (b) are schematic views showing the relationship between the travel directions of the laser beams and the angular position of a stripped conductor; Figs. 12 (a) and 12 (b) are schematic views showing the relationship between the travel directions of the laser beams and the angular position of a stripped conductor; Figs. 13 (a) and 13 (b) are schematic views showing the relationship between the directions of travel of the laser beams and the angular position of a stripped conductor; Fig. 14 is a front elevation of an apparatus inspecting stripped conductors in a second embodiment according to the present invention; Figs. 15 (a) and (15b) are schematic views showing the relationship between the directions of travel of the laser beams and the angular position of a stripped conductor in an apparatus inspecting stripped conductors in a third embodiment according to the present invention; Fig. 16 is a perspective view of an inspection device described in JP-A 6-225423; Fig. 17 is a graph showing the variation of a voltage signal provided by the inspection device shown in FIG. 17; Figs. 18 (a) to 18 (e) are views of defective electrical cables processed by an insulation stripping process; Figs. 19 (a) to 19 (c) are schematic views of help in explaining the problems in the inspection device shown in Fig. 16; and Figs. 20 (a) to 20 (c) are schematic views of help in explaining the problems in the inspection device shown in Fig. 16. DESCRIPTION OF THE PREFERRED MODALITIES The apparatus inspecting stripped conductors in a first mode and in a first mode will be described. second embodiment according to the present invention, with reference to FIGS. 1 to 14. The following description will be made with the assumption that an electrical cable to be inspected extends in a first horizontal direction perpendicular to a vertical direction and moves in a second horizontal direction perpendicular to the first horizontal direction and to the vertical direction . First Mode The construction and operations of the apparatus 100 inspecting stripped conductors in the first embodiment will be described with reference to Figs. 1 to 13. The apparatus 100 inspecting stripped conductors has a main unit 10 which includes a base Ia, an upper arm 11b and a lower arm 11c. The main unit 10 has a shape that substantially resembles the letter U when viewed from the second horizontal direction. An electric cable 1 having a stripped conductor 2 moves in the second horizontal direction indicated by the arrow in Fig. 1 (a). The base Ia of the main unit 10 includes a device 13 that emits laser beams and a device 14 that divides the laser beams, shown in Fig. 2. The device 14 that divides the laser beams divides a laser beam emitted by the device 13 that emits laser beams, also in three laser beams. Three devices, 15a, 15b and 15c, projecting the laser beams are arranged in the upper arm 11b. Each of the devices 15a, 15b, and 15c, which project the laser beams includes lenses and filters. The three devices 15a, 15b, and 15c, projecting laser beams, project laser beams on the conductor 2, which have respectively the same intensities. As shown in Figs. 1 and 2, the laser beams projected by the devices 15a, 15b, and 15c, projecting the laser beams travel along a first optical axis 16, a second optical axis 17 and a third optical axis 18 in the direction and falling on three devices 19a, 19b, 19c receiving the laser beams, such as photodiodes, arranged on the lower arm 11c, respectively.

Each of the laser beams has a width, that is, a dimension with respect to the second horizontal direction, sufficiently larger than the diameter of the stripped conductor 2 and a thickness, ie, a dimension with respect to the first horizontal direction . The width and thickness of each laser beam are, for example, in the order of 5 mm and in the order of 0.3 mm, respectively. Therefore, the laser beams have a shape that resembles a thin ribbon. As shown in Fig. 1, the first optical axis 16, the second optical axis 17 and the third optical axis 18 are contained in a vertical plane parallel to the second horizontal direction. The first optical axis 16 extends vertically. The second optical axis 17 extends obliquely forwardly and the third optical axis 18 extends obliquely rearwardly of the devices 15a, 15b, and 15c, projecting the laser beams, arranged in the upper arm 11b. When viewed from the first horizontal direction, the second optical axis 17 and the third optical axis 18 are symmetrical with respect to the first optical axis 16 and intersect the first optical axis 16 at 45 degrees. The three devices 19a, 19b and 19c receiving the laser beams provide analog voltage detection signals corresponding to the light fluxes of the laser beams incident on them, respectively. The analog detection signals provided by the devices 19a, 19b, 19c receiving the laser beams are converted into corresponding digital signals indicating the luminous flux levels, i.e. the levels of the light fluxes, by means of A / D converters. respectively. The luminous flux levels represented by the analog signals provided by the A / D converters vary in the modes shown in FIG. 3. In Fig. 3 a region 1 is a period before the stripped conductor 2 begins to cross the laser beams, a region 2 is a period immediately after the stripped conductor 2 has begun to cross the laser beams, a region 3 is a period in which the stripped conductor 2 is moving through the laser beams and a region 4 is a period in which the stripped conductor 2 is moving out of the laser beams. The base Ia of the apparatus 100 inspecting stripped conductors is provided with an integrated controller 20, shown in Fig. 2. The digital signals provided by the A / D converters are provided to the three correction devices 21a, 21b and 21c included in the controller 20. The correction devices 21a, 21b and 21c correct the luminous flux levels represented by the analog signals, respectively. More specifically, the voltages of the analog detection signals provided by the three devices 19a, 19b, 19c receiving the laser beams represent the light fluxes of the laser beams falling on the devices 19a, 19b, 19c receiving the beams of laser, respectively. The digital signals provided by the A / D converters represent the voltages of the output signals provided by the devices 19a, 19b, 19c receiving the laser beams, i.e. the light flow levels. The correction devices 21a, 21b and 21c correct the relationship between the digital signals received by the ad converters and the corresponding luminous flux levels, for example by adding a corrective value to or subtracting a corrective value from the digital signals. A correction control unit 22 controls the correction devices 21a, 21b and 21c in such a way that the luminous flux levels represented by the digital signals corrected by the correction devices 21a, 21b and 21c coincide with a predetermined luminous flux level. when the laser beams are not intercepted by the stripped conductor 2. Therefore the luminous flux levels represented by the three digital signals are mutually equal in the region 1 shown in FIG. 3 in which the stripped conductor 2 has not begun to cross the laser beams. The corrected digital signals that represent the luminous flux levels and provided by the three devices 21a, 21b and 21c of correction are provided to a unit 23 that detects the maximum luminous flux value / minimum luminous flux value. When the stripped conductor 2 is advancing and intercepts the laser beams, the luminous flux levels represented by the digital signals provided to the unit 23 which detects the maximum luminous flux value / minimum luminous flux value suddenly falls in region 2 as is shown in Fig. 3. When the luminous flux level represented by at least one of the three digital signals is reduced by a greater decrease of "c" percent of the luminous flux level in region 1, a detector of activation, not shown, included in the unit 23 that detects the maximum luminous flux value / minimum luminous flux value, detects the reduction and activates a sampling function. Then, the unit 23 which detects the maximum luminous flux value / minimum luminous flux value samples the three predetermined times of the received digital signals, at a predetermined time in the region 3, as shown in Fig. 3, in the which the stripped conductor 2 intercepts the larger parts of the laser beams and stores the data on the luminous flux levels in the buffer or buffer memory. The data stored in the buffer memory is examined to determine a maximum and minimum luminous flux level. The maximum and minimum luminous flux levels are provided to a unit 24 that establishes the criteria and to a decision unit. The unit 24 which establishes the criterion, establishes an acceptable luminous flux region as shown in Fig. 3 on the basis of a maximum and minimum luminous flux level determined by inspecting a conductor 2 satisfactorily stripped. The unit 24 that establishes the criterion calculates a luminous flux of upper limit by adding "a" percent of the maximum luminous flux to the maximum luminous flux and calculates a luminous flux of lower limit by subtracting "b" percent from the minimal luminous flux of the minimum luminous flux . An admissible luminous flux region between the upper and lower limit luminous fluxes is a criterion for discriminating between a satisfactorily stripped conductor and a faultily stripped one. A device 26 that introduces the decision level provides the values of "a" percent and "b" to the unit 24 that establishes the percent criterion, to calculate the luminous fluxes limit. Therefore, the criterion can be changed appropriately when the size or type of the electric cable 1 is changed or the level of straightening of the electric cable 1 is changed. The decision unit 25 provides an acceptance signal if both the value of the maximum and minimum luminous flux determined through the inspection of the stripped conductor 2 of the electric cable 1 and that provided by the unit 23 which detects the maximum luminous flux value Minimum luminous flux values are within the acceptable luminous flux range. The decision unit 25 provides a rejection signal if either or both the maximum and minimum luminous flux are outside the allowable luminous flux region. An inspection procedure for stripped conductors to be carried out by the apparatus 100 inspecting stripped conductors in the first embodiment will be described with reference to Figs. 4 to 7. The apparatus 100 inspecting stripped conductors is inspected and a range of permissible luminous fluxes is determined as a criterion, through the inspection of a satisfactorily stripped conductor (eg, the appropriate sample) before beginning the procedure of inspection of stripped conductors. In the apparatus 100 inspecting stripped conductors in the first embodiment, the device 14 dividing the laser beams equally divides a laser beam emitted by the device 13 emitting laser beams in three laser beams, and the three laser beams are distributed to devices 15a, 15b, and 15c, which project the laser beams. The respective intensities of the three laser beams projected onto the conductor 2 stripped along the three optical axes, 16, 17 and 18 by the devices 15a, 15b, and 15c, projecting the laser beams are equal. Therefore, in the region 1 shown in Fig. 3, in which the stripped conductor 2 has not intercepted any of the three laser beams, the luminous flux levels represented by the digital signals provided to the unit 23 which detects the maximum luminous flux value / luminous flux minimum value should be equal. If the luminous flux levels represented by the digital signals are different from each other, a procedure is carried out which corrects the luminous flux level, shown in Fig. 4. The corrections control unit 22 executes the steps SI to S3 to control the operation of the three correction devices 21a, 21b and 21c to balance the luminous flux levels represented by the digital signals provided to the unit 23 which detects the maximum luminous flux value / minimum luminous flux value in the state where the stripped conductor 2 does not intercept any of the three laser beams. The apparatus 100 inspecting stripped conductors is automatically and constantly inspected as long as the procedure inspecting stripped conductors is not in process. Therefore, an operator need not adjust the apparatus 100 that inspects stripped conductors before initiating the inspection of the stripped conductor 2. If the drop of any of the luminous flux levels represented by the digital signals provided by the devices 19a, 19b, 19c receiving the laser beams is greater than a predetermined value, due to dust contamination of one of the devices 15a , 15b, and 15c, which project the laser beams or devices 19a, 19b, 19c that receive the relevant laser beams, the correction devices 21a, 21b and 21c that receive the digital signals representing the reduced light flow level correct the level of luminous flux. Therefore the accuracy of the inspection of stripped conductors can be maintained. Subsequently, a procedure is carried out that establishes a criterion, shown in Fig. 5. The criterion, that is, the acceptable luminous flux range, is established through the inspection of conductors satisfactorily stripped of an electric cable 1. The isolated electric cable 1 having 1 conductor 2 satisfactorily stripped (ie, the proper sample) is fed to the apparatus 100 which inspects stripped conductors in the Sil step. After the start of the interception of the laser beams by the stripped conductor 2, the luminous flux levels represented by the three digital signals provided to the unit 23 which detects the maximum luminous flux value / minimum luminous flux value should drop abruptly in region 2, as shown in Fig. 3. If in step S12 it is decided that the ratio of the drop in the luminous flux level is less than a predetermined ratio of "c" percent, there is a possibility that the apparatus 100 inspecting stripped conductors malfunctions. Therefore in step S13 the method establishing the criterion is interrupted and the apparatus 100 inspecting stripped conductors is inspected in step S14. After the inspection of the apparatus 100 inspecting stripped conductors has been completed, an electric cable 1 having a satisfactorily stripped conductor 2 is fed to the apparatus 100 inspecting stripped conductors. If in step S12 it is decided that the ratio of the fall of the luminous flux level is greater than the predetermined "c" percent relation, the device that detects the activation, included in the unit 23 that detects the maximum luminous flux value / minimum luminous flux value, detects the drop and triggers a sampling function in step S15. Then, the unit 23 that detects the maximum luminous flux value / minimum luminous flux value samples the three digital signals provided thereto at the predetermined times in region 3 of a predetermined time and in step S16 stores in a buffer the data on the luminous flux levels. Then, the unit 23 which detects the maximum luminous flux value / minimum luminous flux value determines a maximum luminous flux and a minimum luminous flux on the basis of the data stored in the buffer and in step S17 provides the unit 24 that the criterion establishes the value of the maximum luminous flux and the minimum luminous flux. The operator operates the device 26 that introduces the level of decision to enter the unit 24 that establishes the criterion the values of the relations to "percent and%" percent relevant for the size and type of the cables 1 to be inspected or the level of straightening, in step S18.

Then, in step S19, the unit 24 that establishes the criterion determines a criterion, that is, an acceptable luminous flux range, as shown in Fig. 3. Therefore, the criterion is established (the luminous flux range acceptable) and the apparatus 100 inspecting stripped conductors is listed to begin a process inspecting stripped conductors for successively inspecting the stripped conductor 2 of the electric cables 1. With reference to Fig. 6 showing the procedure for inspecting conductors (ie, the product) stripped, an electric cable 1 having a stripped conductor 2 to be inspected is fed to the apparatus 100 inspecting conductors stripped in step S21. After the beginning of the interception of the laser beams by the stripped conductor 2, the luminous flux levels represented by the three digital signals provided to the unit 23 that detects the minimum luminous flux / maximum luminous flux value should drop abruptly in a region 2, as shown in Fig. 7. If in step S22 it is detected that the ratio of the drop in the luminous flux level is less than a predetermined ratio of "c" percent, there is a possibility that the apparatus 100 inspecting stripped conductors malfunctions. Therefore, in step S23, the procedure for inspecting stripped conductors is interrupted and the apparatus 100 inspecting stripped conductors is inspected in step S24. After inspection of the apparatus 100 inspecting stripped conductors is completed, an electric cable 1 having a stripped conductor 2 is fed to the apparatus 100 inspecting stripped conductors. If in step S22 it is decided that the ratio of the fall of the luminous flux level is greater than the predetermined "c" percent relation, the device that detects the activation, included in the unit 23 that detects the luminous flux value maximum / minimum luminous flux value, detects the drop and triggers a sampling function in step S25. Then, the unit 23 that detects the maximum luminous flux value / minimum luminous flux value samples the three digital signals provided thereto at the predetermined times in region 3 of a predetermined time, and in step S26 bufferizes the data. on the luminous flux levels. Then, in step S27, the unit 23 that detects the maximum luminous flux value / minimum luminous flux value determines a maximum luminous flux value and a minimum luminous flux based on the data stored in the buffer and provides the values of maximum and minimum luminous flux to the decision unit 25.

Then, in step S28, the decision unit 25 examines the maximum and minimum luminous flux values received from the unit 23 which detects the maximum luminous flux value / minimum luminous flux value. If the values of the maximum luminous flux and the minimum luminous flux are in accordance with the criterion, that is, if the maximum luminous flux and the minimum luminous flux are within the acceptable luminous flux range, the decision unit 25 provides an acceptance signal in step S29. If the maximum and minimum luminous fluxes do not resemble the criterion, that is, if the maximum luminous flux and the minimum luminous flux are not within the acceptable luminous flux range, the decision unit 25 provides a rejection signal in the step S30. Assume that the conductor of the electric cable 1 includes a central wire and six wires arranged at equal angular intervals around the central wire as shown in Figs. 8 to 13. Then, in some cases, the loss of some of the threads of the stripped conductor 2 can not be detected depending on the angles between the adjacent optical axes 16, 17, 18 along which the beams of the conductor travel respectively. To be.

Assume that the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 is 30 degrees as shown in Figs. 8 (a) and 8 (b). Then if stripped conductor 2 is in an angular position shown in Fig. 8 (a), the loss of any of the wires 2a and 2b 'marked with a circle (0) can be detected through the measurement of a width 2 of the shadow of the laser beam traveling along the optical axis 17 obscured by the driver 2 stripped. Similarly, the loss of any of the wires 2a 'and 2b marked with a circle can be detected by measuring a width 3 of the shadow of the laser beam traveling along the optical axis 18 obscured by the driver 2 stripped. However, the requested either of the upper thread 2c and the lower thread 2d marked with a cross can not be detected, since the upper thread 2d and the lower thread 2d overlap with other thread OSs with respect to the directions in which the optical axes 16, 17 and 18 extend. If the stripped conductor 2 is in an angular position as shown in Fig. 8 (b) the loss of any of the wires 2a 'and 2b marked with a circle can be detected through the measurement of a width 1 of the shadow of the laser beam traveling along the optical axis 16 obscured by the stripped conductor 2. However, the order of any of the threads 2a, 2c, 2d and 2b 'marked with a cross can not be detected since those threads overlap with other threads with respect to the directions in which the axes 17 and 18 extend. optical Therefore, when the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 is 30 degrees, the loss of any of the threads marked with a cross in Fig. 8 can not be detected. Assume that the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 is 37.5 degrees as shown in Figs. 9 (a) and 9 (b). Then if the stripped conductor 2 is in an angular position shown in Fig. 9 (a), the loss of any of the wires 2a and 2b 'marked with a circle can be detected through the measurement of a width 2 of the shadow of the laser beam traveling along the optical axis 17, obscured by the stripped conductor 2. Similarly, the loss of any of the wires 2a 'and 2b marked with a circle can be detected by measuring a width 3 of the shadow of the laser beam traveling along the optical axis 18 obscured by the driver 2 stripped. However, the loss of either the upper thread 2c and the lower thread 2d marked with a cross can not be detected since the upper thread 2c and the lower thread 2d overlap with other threads with respect to the directions in which they extend axes 16, 17 and 18, optical. If the stripped conductor 2 is in an angular position shown in Fig. 9 (b), the loss of any of the wires 2a 'and 2b marked with a circle, can be detected through the measurement of a width 1 of the shadow of the laser beam traveling along the optical axis 16 obscured by the stripped conductor 2. Similarly, the loss of any of the wires 2a and 2b 'can be detected by measuring a width 2 of the shadow of the laser beam traveling along the optical axis 17 obscured by the stripped conductor 2. The loss of any of the wires 2c and 2d can be detected by measuring a width 3 of the shadow of the laser beam traveling along the optical axis 18 obscured by the stripped conductor 2. Therefore, when the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 37.5 degrees, the loss of the yarns apart from the upper yarn 2c and the lower yarn 2d, can be detected if the Stripped conductor 2 is in the angular position shown in Fig. 9 (a).

Assume that the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 45 degrees, as shown in Figs. 10 (a) and 10 (b). Then, if the stripped conductor 2 is in an angular position shown in Fig. 10 (a), the loss of any of the wires 2a and 2b 'marked with a circle can be detected through the measurement of a width 2 of the shadow of the laser beam traveling along the optical axis 17 obscured by the stripped conductor 2. Similarly, the loss of any of the wires 2a 'and 2b marked with a circle can be detected by measuring a width 3 of the shadow of the laser beam traveling along the optical axis 18 obscured by Driver 2 stripped. However, the loss of either of the upper thread 2c and the lower thread 2d marked with a cross can not be detected since the upper thread 2c and the lower thread 2d overlap with other threads, with respect to the directions in which extends axes 16, 17 and 18, optical. If the stripped conductor 2 is in an angular position shown in Fig. 10 (b), the loss of any of the wires 2a 'and 2b marked with a circle, can be detected through the measurement of a width 1 of the shadow of the laser beam traveling along the optical axis 16 obscured by the stripped conductor 2. Similarly, the loss of any of the wires 2a and 2b 'can be detected by measuring a width 2 of the shadow of the laser beam traveling along the optical axis 17 obscured by the stripped conductor 2. The loss of any of the wires 2c and 2d can be detected by measuring a width 3 of the shadow of the laser beam traveling along the optical axis 18 obscured by the stripped conductor 2. Therefore, when the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 45 degrees, the loss of the yarns, not including the upper yarn 2c and the lower yarn 2d, can be detected if the stripped conductor 2 is in the angular position shown in Fig. 10 (a). Assume that the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 52.5 degrees as shown in FIGS. 11 (a) and 11 (b). Then if the stripped conductor 2 is in an angular position shown in Fig. 11 (a), the loss of any of the wires 2a and 2b ', marked with a circle, can be detected through the measurement of a width 2 of the shadow of the laser beam traveling along the optical axis 17 obscured by the stripped conductor 2. Similarly, the loss of any of the wires 2a 'and 2b marked with a circle can be detected by measuring a width 3 of the shadow of the laser beam traveling along the optical axis 18, shaded by the driver 2 stripped. However, the loss of either the upper thread 2c and the lower thread 2d, marked with a cross, can not be detected since the upper thread 2c and the lower thread 2d overlap with other thread, with respect to the directions in the which axes 16, 17 and 18 extend optical. If the stripped conductor 2 is in an angular position shown in Fig. 11 (b), the loss of any of the wires 2a 'and 2b marked with a circle, can be detected through the measurement of a width 1 of the shadow of the laser beam traveling along the optical axis 16 obscured by the stripped conductor 2. Similarly, the loss of any of the wires 2a and 2b 'can be detected by measuring a width 2 of the shadow of the laser beam traveling along the optical axis 17, obscured by the stripped conductor 2 . The loss of any of the wires 2c and 2d can be detected by measuring a width 3 of the shadow of the laser beam traveling along the optical axis 18 obscured by the stripped conductor 2. Thus, when the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 52.5 degrees, the loss of the yarns, not including the upper yarn 2c and the lower yarn 2d, can be detected if the driver 2 stripping is in the angular position shown in FIG. 11 (a). Assume that the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 60 degrees as shown in Figs. 12 (a) and 12 (b). Then, if the stripped conductor 2 is in an angular position shown in Fig. 12 (a), the loss of any of the wires 2a, 2a ', 2b, 2b', 2c and 2d can not be detected since each of these threads is overlapped with other threads, with respect to the directions in which the optical axes 16, 17 and 18 extend. If the stripped conductor 2 is in an angular position shown in Fig. 12 (b), the loss of any of the wires 2a 'and 2b, marked with a circle can be detected through the measurement of a width 1 of the shadow of the laser beam traveling along the optical axis 16 obscured by the stripped conductor 2, the loss of any of the wires 2a and 2b 'can be detected through the measurement of a width 2 of the shadow of the beam laser traveling along the optical axis 17 obscured by the stripped conductor 2 and the loss of either of the wires 2c and 2d can be detected through the measurement of a width 3 of the shadow of the laser beam traveling the along the optical axis 18 obscured by the stripped conductor 2. Therefore, when the angle between the optical axis 16 and 17 and the angle between the optical axes 16 and 18 are 60 degrees, the loss of some of all the wires 2a, 2a ', 2b, 2b', 2c and 2d arranged around the central thread can not be detected if the stripped conductor 2 is in the angular position shown in FIG. 12 (a). Assume that the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 67.5 degrees as shown in Figs. 13 (a) and 13 (b). Then, if the stripped conductor 2 is in an angular position shown in FIG. 13 (a), the loss of either the upper thread 2c and the lower thread 2d marked with a circle can be detected through the measurement of a width 2 of the shadow of the laser beam traveling along the optical axis 17 , and a width 3 of the shadow of the laser beam traveling along the optical axis 18 obscured by the stripped conductor 2. However, the loss of any of the threads 2a, 2a ', 2b and 2b' marked with a cross can not be detected since each of these threads overlaps with other threads, with respect to the directions parallel to the axes 16 , 17 and 18 optics, if the stripped conductor 2 is in the angular position shown in Fig. 13 (a). If the stripped conductor 2 is in an angular position shown in Fig. 13 (b), the loss of any of the wires 2a 'and 2b marked with a circle can be detected by measuring a width of the shadow 1 of the laser beam traveling along the optical axis 16, obscured by the stripped conductor 2, the loss of any of the wires 2a and 2b 'can be detected through the measurement of a width 2 of the shadow of the beam of laser traveling along the optical axis 17, obscured by the stripped conductor 2, and the loss of either of the wires 2c and 2d can be detected through the measurement of a width 3 of the shadow of the laser beam that it travels along the optical axis 18 obscured by the stripped conductor 2. Therefore, when the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 67.5 degrees, the loss of some of the wires 2a, 2a ', 2b and 2b' can not be detected if the stripped conductor 2 is in the angular position shown in Fig. 13 (a). The apparatus 100 inspecting stripped conductors in the first embodiment is used to inspect the driver 2 Stripper having the individual central yarn and the six yarns arranged at equal angular intervals around the central yarn, as for the yarns lost. The devices 15a, 15b, and 15c, projecting the laser beams of the apparatus 100 inspecting stripped conductors project the laser beams to travel along the optical axis 16, the optical axis 17 inclined at 45 degrees relative to the axis 16 , and the optical axis 18 inclined at 45 degrees with respect to the optical axis 16, as seen in a vertical plane perpendicular to the first horizontal direction. Consequently, the possibility of a condition where the threads overlap each other with respect to the directions parallel to the optical axes 16, 17 and 18, can be limited to the smallest possible extent. When the stripped conductor 2 is in the angular position shown in Fig. 10 (a), the loss of either the upper thread 2c and the lower thread 2b can not be detected. However, the stripping edges of the stripper blade, for stripping an end portion of the insulator of the electric cable 1, are arranged in such a way that the wires 2a, 2a ', 2b and 2b' are necessarily cut by the stripping edges. when any of the yarn 2c and the yarn 2d are cut by the stripping edges. Therefore, the apparatus 100 inspecting stripped conductors in the first embodiment can detect the loss of strings of the stripped conductor 2 with satisfactory accuracy practically, with reliability. The apparatus 100 inspecting stripped conductors projects the laser beams along the first optical axis 16, the optical axis 17 inclined at 45 degrees relative to the optical axis 16, and the optical axis 18 inclined at 45 degrees relative to the axis 16 optical as observed in a vertical plane perpendicular to the first horizontal direction. The operation and effect of the apparatus 100 inspecting stripped conductors are the same even if the angle between the optical axes 16 and 17 and the angle between the optical axes 16 and 18 are 36.5 degrees, as shown in Fig. 9 or of 52.5 degrees as shown in Fig. 11. Second Mode A system 200 for inspection of stripped conductors in a second embodiment according to the present invention will be described with reference to Fig. 14. The apparatus 200 inspecting stripped conductors is it constructs having in the second horizontal direction two apparatuses that inspect stripped conductors of the same type as the apparatus 100 that inspects stripped conductors in the first embodiment, that is, a first apparatus 100 inspecting stripped conductors and a second apparatus 30 inspecting stripped conductors.

The first apparatus 100 inspecting stripped conductors is identical with the apparatus 100 inspecting stripped conductors in the first embodiment. The second apparatus 30 inspecting stripped conductors has a vertical optical axis 16, an oblique optical axis 17 inclined at 67.5 degrees relative to the optical axis 16, and an oblique optical axis 18 inclined at 67.5 degrees relative to the vertical optical axis 16. An electric cable 1 having a stripped conductor 2 to be inspected moves in a fixed angular position in the second horizontal direction, that is to say, a direction to the right as seen in Fig. 14, in such a way that the conductor 2 Stripper is inspected successively by the first apparatus 100 inspecting stripped conductors and the second apparatus 30 inspecting stripped conductors. While the apparatus 100 inspecting stripped conductors, in which the optical axes 17 and 18 are inclined at 45 degrees relative to the optical axis 16, can not detect the loss of any of the wires 2c and 2d as mentioned in connection with Fig. 10 (a), the second apparatus 30 inspecting stripped conductors, in which the optical axes 17 and 18 are inclined at 67.5 degrees relative to the optical axis 16, can detect the loss of any of the wires 2c and 2d as mentioned in connection with Fig. 13 (a). Therefore, the system 200 inspecting stripped conductors in the second embodiment, which includes the first apparatus 100 inspecting stripped conductors and the second apparatus 30 inspecting stripped conductors in combination, can reliably detect the loss of any of the six strings 2a, 2a ', 2b, 2c', 2c and 2d arranged around the central thread. Third Mode An apparatus 300 inspecting stripped conductors in a third embodiment, according to the present invention, will be described with reference to Fig. 15. The apparatus 300 inspecting stripped conductors in the third embodiment is constructed by incorporating improvements in the apparatus 100. that inspects stripped drivers in the first mode. The apparatus 300 inspecting stripped conductors uses four laser beams, that is, a first laser beam projected along a vertical optical axis 16, a second laser beam projected along an oblique optical axis 17 inclined at 37.5. degrees relative to the optical axis 16, a third laser beam projected along an oblique optical axis 18 at 37.5 degrees relative to the optical axis 16 and a fourth laser beam projected along an inclined oblique optical axis 18 ' at 67.5 degrees relative to the optical axis 16.

When the laser beams project only along the first optical axis 16 and the oblique optical axes 17 and 18 inclined at 37.5 degrees relative to the vertical optical axis 16, the loss of either the upper thread 2c and the lower thread 2d, it can not be detected, as mentioned above in connection with Fig. 9 (a). As mentioned above in connection with Fig. 13, the loss of the wires 2c and 2d can be detected when the laser beam is projected along the optical axis 18 'tilted to 67.5 degrees relative to the optical axis 16. Therefore, the apparatus 300 inspecting stripped conductors in the third embodiment, can detect the loss of any of all six wires 2a, 2a ', 2b, 2b', 2c and 2d, arranged around the central wire. Although the angles between the optical axes s 16 and 17 and between the optical axes 16 and 18 are 37.5 degrees to provide a space to install a device that projects the laser beams, to project the four laser beams along the axis 18 'inclined at 67.5 degrees relative to the optical axis 16 in the apparatus 300 inspecting stripped conductors, in the third embodiment, the angles between the optical axes 16 and 17 and between the optical axes 16 and 18 can be 45 degrees. Although the optical axis 18 ', along which the fourth laser beam projects, extends in front of the optical axis 16, five laser beams can be used including an additional laser beam projected along an extended optical axis behind the optical axis 16 and inclined at 67.5 degrees relative to the optical axis 16. The devices projecting the laser beams can be arranged to project the laser beams obliquely upwards from a position opposite the optical axis 16 and a position behind the optical axis 16, respectively. Naturally, a single laser beam emitted by a single device that emits a laser beam is equally divided into those laser beams distributed to the devices that project the laser beams. Although the optical axis 16 of each of the above embodiments is vertical, the optical axis 16 may be inclined forward or backward if spaces are required for the devices projecting the laser beams. Although apparatuses inspecting stripped conductors have been described in the preferred embodiments, it should be understood that the present invention is not limited in its practical application to those apparatuses inspecting stripped conductors, specifically described herein, and many changes and variations can be made therein. these without departing from the scope and spirit of the invention.

Claims

CLAIMS 1. An apparatus that inspects stripped conductors to inspect a conductor stripped of an electric cable, exposed when stripping or stripping an extreme part of an insulator included in the electric cable, irradiating the conductor stripped with laser beams, said apparatus that inspects conductors strips, characterized in that it comprises: means projecting laser beams, capable of projecting laser beams on the stripped conductor of the electric cable extended in a first horizontal direction and moving in a second horizontal direction perpendicular to the first horizontal direction, respectively in a vertical direction, and obliquely in the forward direction with respect to the second horizontal direction and an obliquely backward direction with respect to the second horizontal direction; means receiving the laser beams, capable of receiving the laser beams projected by the means projecting the laser beams and of providing signals of the measured voltages proportional to the light fluxes of the received laser beams; and a decision means for deciding whether the stripped conductor is intact or not, based on the criteria and the measured voltages of the signals provided by the means receiving the laser beams representing the light fluxes of the received laser beams. The apparatus inspecting stripped conductors according to claim 1, characterized in that the means projecting laser beams are arranged in such a way that one of the laser beams is vertical, and the other two laser beams projected obliquely forward. and backward they are inclined at equal angles, respectively, relative to the vertical laser beam in a vertical plane perpendicular to the first horizontal direction. The apparatus that inspects stripped conductors according to claim 1, characterized in that the means projecting the laser beams include: a first means projecting laser beams arranged to project the laser beam obliquely at a first angle relative to the vertical laser beam in a vertical plane perpendicular to the first horizontal direction, and a second means projecting laser beams arranged to project the laser beam obliquely at a second angle relative to the vertical laser beam in a vertical plane perpendicular to the first horizontal direction. The apparatus inspecting stripped conductors according to any of claims 1 to 3, characterized in that the stripped conductor has a central wire and six wires arranged around the central wire at equal angular intervals, and the means projecting the laser beams , project the laser beams obliquely forward and obliquely backwards, respectively, at an angle between 37.5 degrees and 52.5 degrees relative to the vertical laser beam, in a vertical plane perpendicular to the first horizontal direction. The apparatus that inspects stripped conductors according to any of claims 1 to 4, characterized in that it further comprises: a means that emits laser beams to emit a laser beam, and a means that divides the laser beam to divide by same as the laser beam emitted by the means that emits the laser beam in laser beams and distribute the laser beams to the means projected by the laser beams. The apparatus inspecting stripped conductors according to claim 5, characterized in that it further comprises: correction means for correcting the luminous flux levels corresponding to the measured voltages of the signals provided by the means receiving the laser beams, and a correction control means for individually controlling the operations of the correction means; wherein the correction control means controls the correction means in such a way that the luminous flux levels corresponding to the voltages measured after the corrections made by the correction means, are equal to each other in a state where the laser beams are not intercepted by the stripped conductor. The apparatus that inspects stripped conductors according to any of claims 1 to 6, characterized in that it comprises: means that detect the maximum and minimum luminous flux to detect the maximum and minimum luminous fluxes between the "luminous" flows represented by the voltages provided by the means receiving the laser beams at a predetermined time when a satisfactorily stripped conductor is inspected, a means that establishes the criteria for establishing a luminous flow of upper limit calculated by adding "percent of the maximum luminous flux to the maximum luminous flux and a luminous flux of lower limit, calculated by subtracting "% of the minimum luminous flux from the minimum luminous flux as the criterion, and a decision means, which decides that the stripped conductor is intact when the fluxes luminous ones represented by the measured voltages provided by the means that receive the beams of laser during the inspection of the stripped conductor are within a range of luminous fluxes permissible between the upper flow luminous flux and the lower limit luminous flux. 8. The apparatus inspecting stripped conductors according to claim 7, characterized in that it further comprises an input means of the level d reference to provide the values of ?? to "percent and of,? B" percent as the levels of reference for the means that establish the criterion. 9. The apparatus that inspects stripped conductors according to claim 7 or 8, characterized in that the means detecting the maximum and minimum luminous fluxes begin to detect the maximum and minimum luminous fluxes after the reduction of the luminous flux represented by the measured voltage. provided by the means receiving the laser beams, under a predetermined luminous flux. 10. A system inspecting stripped conductors, characterized in that it compr: a first apparatus inspecting stripped conductors analogous to the apparatus inspecting stripped conductors established in the claim; and a second apparatus inspecting stripped conductors analogous to the stripping conductor inspecting apparatus set forth in claim 1; wherein the first apparatus inspecting stripped conductors uses a vertical laser beam and two oblique laser beams inclined in opposite directions, respectively at a first angle with respect to the vertical laser beam, and the second apparatus inspecting stripped conductors uses a beam of vertical laser and two oblique laser beams inclined in opposite directions, respectively, at a second angle different from the first angle, relative to the vertical laser beam.