Abstract:
Disclosed is an improved wire-length measuring apparatus including a rising-and-descending roller unit, which is designed to be lowered to pull down all or selected wires stretched under tension and each fed out of an associated wire supply reel to measure the wires in terms of a different level at which the wires are pulled down. The roller unit has upper and lower rollers. When the roller unit rises to an upper level for measuring a subsequent shorter wire length, some selected wires are withdrawn so that their valley points come up to the upper level. Pinch rollers are designed to invade somewhat the area between the upper and lower rollers of the roller unit just before the wire measurement starts, thereby keeping the withdrawn wires pushed against the upper and lower rollers just before the wire measurement is completed. As a result, curling of the withdrawn wires can be prevented.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a wire-length measuring apparatus, and more particularly to an improved wire-length measuring apparatus using rising-and-descending rolls. 
     DESCRIPTION OF THE PRIOR ART 
     As is well know, electric harnesses whose insulated wires have electric connectors press-connected at one or both ends are used to connect one and another electric apparatuses. The insulated wires of such electric harnesses are of different lengths, and are selected to meet occasional length requirements. Accordingly apparatuses for making electric harnesses are designed to measure and cut desired lengths of insulated wires and press-connect electric connectors to one or both ends each of the so measured-and-cut insulated wires. 
     FIGS. 30 and 31 schematically show a conventional apparatus for making electric harnesses. It includes a rising-and-descending roll unit 45, the roll 46 of which is lowered to pull down a length of wire stretched under tension and fed out of an associated wires supply reel 40 to measure the wire w in terms of the level at which the wire w is pulled down. In the drawings, a guide roll is indicated at 41, a connector-carrier for supplying connectors R is indicated at 42, a wire-clamping cylinder is indicated at 43, and a counter roll is indicated at 44. 
     The apparatus is useful in measuring wires. However, it has the following deficiency. As seen from FIG. 31, after measuring the wire w, the roll 46 of the rising-and-descending roll unit 45 is allowed to rise to its original position, and then the pull-out wire w is released from tension. Then the part of the pull-out wire w extending from the roll 46 of the rising-and-descending roll unit 45 to the electric connector press-connected end is liable to curl. Disadvantageously the curling prevents the rising of the rising-and-descending roll unit 45, and causes the tangling of wires. Accordingly the wire measuring and connector press-connecting cannot be performed at an increased efficiency. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a wire-length measuring apparatus which allows wires to descend naturally under gravity without curling after being released from tension subsequent to completion of wire measurement, thus assuring smooth rising of the roll unit and avoiding the tangling of the wires, and accordingly improving the efficiency with which electric: harnesses are manufactured. 
     To attain this and other objects a wire-length measuring apparatus including a rising-and-descending roll unit, the roll of which is lowered to pull down wires stretched under tension and each fed out of an associated wire supply reel to measure wires in terms of a different level at which the wires are pulled down, is improved according to the present invention in that: aid roll unit has a lower roll to pull down wires and an upper roll spaced from said lower roll; and said apparatus further comprises a pinch roll unit which comprise at least one pinch roll to invade somewhat the area between said upper and lower rolls of said roll unit on the side opposite to the wire-supplying side before said lower roll start for wire measurement, thereby keeping the wire pushed against the surfaces of said upper and lower rolls just before the wire measurement is completed. 
     With this improved arrangement the pinch roll invades somewhat the area between said upper and lower rolls of said roll unit on the side opposite to the wire-supplying side before said lower roll starts for wire measurement, that is, before the lower roll descends to a selected level, thereby keeping the wire pushed against the surfaces of the upper and lower rolls, and releasing the pinch roll just before the wire measurement is completed. The part of the wire length between the lower roll and the press-connected wire end is prevented from curling. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the present invention will be understood from the following description of harness manufacturing apparatuses according to preferred embodiments of the present invention, which are shown in accompanying drawings: 
     FIG. 1 schematically shows a wire-length measuring apparatus of the present invention, feeding a plurality of insulated wires each having an electric connector press-connected at its one end; 
     FIG. 2 is a perspective view of the measuring part of the wire-length measuring apparatus of FIG. 1; 
     FIG. 3 schematically shows the wire-length measuring apparatus starting the measuring of the wires; 
     FIG. 4 is a perspective view of the measuring part of the wire-length measuring apparatus starting the measuring of the wires; 
     FIG. 5 schematically shows the wire-length measuring apparatus in the condition that it pinch rollers start rising; 
     FIG. 6 is a perspective view of the measuring part of the wire-length measuring apparatus in the condition of FIG. 5; 
     FIG. 7 schematically shows the wire-length measuring apparatus in the condition that its pinch rollers are in operating position, performing wire measurement for a longest length; 
     FIG. 8 is a perspective view of the measuring part of the wire-length measuring apparatus in the condition of FIG. 7; 
     FIG. 9 schematically shows the wire-length measuring apparatus in the condition that its pinch rollers have returned to their original positions after completion of wire measurement for a longest length; 
     FIG. 10 is a perspective view of the measuring part of the wire-length measuring apparatus in the condition of FIG. 9; 
     FIG. 11 schematically shows the wire-length measuring apparatus in the condition that its roller unit starts rising to the level at which a second longest length measurement is effected; 
     FIG. 12 is a perspective view of the measuring part of the wire-length measuring apparatus in the condition that selected wires have been withdrawn to the wire supply reels for a second longest measurement; 
     FIG. 13 is a perspective view of the measuring part of the wire-length measuring apparatus in the condition that measurements of all wires have been completed; 
     FIG. 14 is a front view of the roller unit and the pinch rollers in combination; 
     FIG. 15 is a left side view of the combination of FIG. 14; 
     FIG. 16 is a front view of the lower roller of the rollers unit; 
     FIG. 17 is a longitudinal section of the lower roller taken along the line Z--Z in FIG. 16 
     FIG. 18 schematically shows a wire-length measuring apparatus according to a second embodiment prior to the starting of wire measurement; 
     FIG. 19 schematically shows the wire-length measuring apparatus of FIG. 18 starting the measuring of the wires; 
     FIG. 20 schematically shows the wire-length measuring apparatus of FIG. 18 in the condition that its roller unit starts to lower; 
     FIG. 21 schematically shows the wire-length measuring apparatus of FIG. 18 in the condition that wire measurement is effected; 
     FIG. 22 schematically shows the wire-length measuring apparatus of FIG. 18 in the condition that its pinch rollers return to their original positions; 
     FIG. 23 schematically shows the wire-length measuring apparatus of FIG. 18 in the condition that its roller unit starts to rise to the level at which a second longest length measurement is effected; 
     FIG. 24 schematically shows a wire-length measuring apparatus according to a third embodiment prior to the start of wire measurement; 
     FIG. 25 schematically shows the wire-length measuring apparatus of FIG. 24 starting to measure the wires; 
     FIG. 26 schematically shows the wire-length measuring apparatus of FIG. 24 in the condition that its roller unit starts to lower; 
     FIG. 27 schematically shows the wire-length measuring apparatus of FIG. 24 in the condition that wire measurement is effected; 
     FIG. 28 schematically shows the wire-length measuring apparatus of FIG. 24 in the condition that its pinch rollers have returned to their original positions; 
     FIG. 29 schematically shows the wire-length measuring apparatus of FIG. 24 in the condition that its roller unit starts to rise to the level at which a second longest length measurement is effected; 
     FIG. 30 schematically shows a conventional wire-length measuring apparatus of the prior art; and 
     FIG. 31 schematically shows how the prior art wire-length measuring apparatus causes the curling of the measured wires. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 to 17 show a wire-length measuring apparatus according to a first embodiment of the present invention. First, referring to FIG. 1 to 13, a description is given as to how the measuring of a plurality of wires, particularly five wires W1 to W5 may be effected. 
     Referring to FIG. 1, wire supply reels 1, wireclamping cylinders 4, guide roller 2, and electric connector carrier 3 are allotted for different wires W1 to W5 to be measured respectively, and these components are arranged laterally at the same intervals a these wires. These parallel wire supply reels 1, the parallel wireclamping cylinders 4 and a counter roller 5, the parallel guide roller 2 and the parallel electric connector carriers 3 are arranged in the order named longitudinally in the direction &#34;A&#34; in which the parallel wire supply reels 1 feed the wires W1 to W5. 
     FIG. 1 shows the wire-length measuring apparatus in condition that all wires W1 to W5 having electric connector R press-connected at their ends are stretched by moving the electric connector carrier 3 rightward and by stopping it at a predetermined position, thus extending all wires over a predetermined length. After the wire-feeding stops, a backward rotating force is applied to the wire supply reels 1 by appropriate spring means to stretch the wires W1 to W5 in tension. In these drawings, devices from press-connecting electric connector R to the ends of wires W1 to W5 are omitted for the sake of simplicity of drawing. 
     As seen from FIG. 1, a rising-and descending roller unit 6 is placed between the guide rolls 2 and a right fixed position to which the electric connector R is brought by the electric connector carrier 3. This roller unit 6 comprises a roller support 7, a lower roller 9 rotatably fixed to the roller support 7, and an upper roller 8 spaced a given distance from the lower roller 9 and fixed to the roller support 7. As seen from FIGS. 16 and 17, the lower roller 9 has grooves 17 made its circumference to receive the wires W1 to W5. 
     A pinch roller unit 10 is positioned between the guide roller 2 and the right fixed position, opposite to the rising-and-descending roller unit 6. It comprises a rising-and-descending support 11 and two swingable arms 12 and 14. These arms 12 and 14 are swingably fixed to the support 11, and they have pinch rollers 13 and 15 at their ends. Some details of such pinch roll unit 10 are shown in FIGS. 14 and 15, and will be later described. 
     With reference to FIGS. 1 to 13 a series of measuring operations are described below. First, as shown in FIGS. 1 and 2, electric connector R is press-connected to the ends of all wires W1 to W5 by a press-connecting unit (not shown), and then, the so press-connected electric connector R is carried in the right direction A by the electric connector carrier 3. After the feeding of all wires W1 to W5 stops, the wire supply rolls 1 are rotated counterward to pull all wires W1 to W5 backward, thereby stretching these wires under tension. In this condition the roller unit 6 remains at the raised, original position whereas the pinch roller unit 10 remains at the lowered, original position, keeping its swingable arms 12 and 14 open, and hence keeping the pinch rolls 13 and 15 apart from each other. 
     Then, the roller unit 6 is lowered to cause all wires W1 to W5 to yieldingly descend as indicated at B in FIGS. 3 and 4, thus starting the wire measurement. Specifically, all wires W1 to W5 are fitted in the circumferential grooves 17 of the lower roller 9, and are pulled down. When these descending wire form an angle of for instance, 60 degrees, the pinch rollers 13 and 15 are moved longitudinally to come close to the two sides of the &#34;V&#34;-shaped descending wires as indicated at arrows C. 
     The roller unit 6 continues descending as indicated by arrow D in FIGS. 5 and 6. The descending amount depends on a wire length to be determined. The pinch rollers 13 and 15 advance full distance forward, and the pinch roller unit 10 starts rising as indicated by arrow E. 
     Now, assume that two wires W4 and W5 are determined for a longest length L1 and that three remaining wires W1, W2 and W3 are determined for a second longest length L2. First, all wires W1 to W5 are lowered to the lowest level corresponding to the longest length L1 by the roller 9. Before starting the longest length wire measurement subsequent to the pulling-down of all wires to the lowest level, the swingable arms 12 and 14 come close to each other as indicated by arrows F in FIGS. 7 and 8 to permit the pinch rollers 13 and 15 to invade somewhat the area between the upper and lower rolls 8 and 9 (for instance, 1 millimeter inside) on either side of the roller unit 6. 
     Thus, upon wire measurement all wires W1 to W5 are kept pushed against the upper and lower rolls 8 and 9 by the pinch rolls 13 and 15. 
     The inventor found that the wire measurement effected in this condition has the effect of preventing the curling of wires between the lower roller 9 and the electrical connector press-connected wire ends. The pinch rollers 13 and 15 are released just before completion of the wire measurement. The swinging of the swingable arms may be controlled with the aid of cam plates 16. 
     As shown in FIGS. 9 and 10, the pinch rollers 13 and 15 are retracted as indicated by arrows G just before completion of the longest wire measurement, and at the same time, the support 11 starts returning to the lower, original position as indicated by arrow H. After that, the roller unit 6 starts rising. 
     All wires W1 to W5 are extended to the longest length L1, even though three W1, W2 and W3 of these wires will ultimately be shorter than the remaining two wires W4 and W5. Then, the roller unit 6 rises as indicated by arrow J in FIG. 11 until its lower roller 9 reaches the second lower level corresponding to the second longest length L2. 
     As shown in FIG. 12, the wires W1 to W3 to be measured for the second longest length L2 are withdrawn toward the associated wire supply reels 1 as indicated by arrow K, thereby performing the second longest wire measurement. The pinch roller 13 returns to its original position. The other pinch roller 15, however, remains in the same invading-and pushing position as before, as indicate by arrow M. Thus keeping the pushes W1 to W3 pushed against the upper and lower rollers 8 and 9 during wire measurement, and then, the pinch roll 15 leaves the area between the upper and lower rolls 8 and 9 just before completion of wire measurement. 
     The longest and second longest measurements of all wires W1 to W5 are completed, and then, the roller unit 6 rises as indicated by arrow N and the pinch rolls 13 and 15 return to their original positions P, as shown in FIG. 13. 
     Electric connectors L (FIG. 12) may be press-connected to the other or left ends of the longest and second longest wires, or the other or left ends of these wires may be left free of electric connectors. 
     The operations of the pinch rollers 13 and 15 in determining different lengths L1 and L2 are described above. In determining a single wire from a given length or in determining a plurality of wires to be equal in length the pinch rollers 13 and 15 are apart from each other upon completion of a single required wire measurement, descending and returning backward to their original positions. 
     FIG. 14 shows one example of the roller unit as using a reversing motor 18 to raise or lower the roller unit body 6. Specifically, rotation of the motor 18 is transmitted to sprocket wheels 19 and 20 to cause rotation of an associated screw shaft 21 to raise or lower an associated rising-and-descending piece 22, thereby causing an associated support arm 23 to rise or descend, and accordingly permitting the upper and lower rolls 8 and 9 to rise or descend. This rising and descending may be effected smoothly thanks to a guide means 25 on a guide rail 24. 
     The controlling of the descending distance to perform a required length measurement, and the controlling of rising and descending timing may be made by a control for the motor. 
     As shown in FIGS. 14 and 15, a rising-and-descending cylinder 26 may be used in raising, and lowering the pinch rollers 13 and 15. Specifically, the rising-and-descending of the cylinder 26 causes associated rising-and-descending plates 29 to rise and descend under the guidance of guide means 27 and 28, accordingly raising and lower the pinch rollers 13 and 15. A reciprocating cylinder 30 may be used in reciprocating the pinch roller 13 and 15. Specifically, the pinch rolls 13 and 15 may be connected to the reciprocating cylinder 30 via a connecting rod 31. Other appropriate drive means may be used. 
     Referring to FIGS. 18 to 23, wire-length measuring apparatus according to a second embodiment is described. This apparatus is different from the first embodiment only in that: the second embodiment uses only one pinch roller 13 whereas the first embodiment uses two pinch rollers 13 and 15. The use of one pinch roller, however, still has the effect of preventing the curling of the portions of the wires extending from the electric connector press-connected ends to the lower roller 9 of the roller unit 6. 
     First, as shown in FIG. 18, electric connector R is press-connected to the right ends of all wires W1 to W5, and then, the so press-connected electric connector R is carried in the right direction A by the electric connector carrier 3. After the feeding of all wires W1 to W5 stops, the wire supply rolls 1 are rotated counterward to pull all wires W1 to W5 backward, thereby stretching these wires under tension. In this condition the roller unit 6 remains at the raised, original position whereas the pinch roller unit 10 remains at the lowered, original position, keeping its swingable arm 12 open, and hence keeping the pinch roller 13 withdrawn. 
     Then, the roller unit 6 is lowered to cause all wires W1 to W5 to yieldingly descend as indicated at B in FIG. 19, thus starting the wire measurement. Specifically, all wires W1 to W5 are fitted in the circumferential grooves 17 of the lower roller 9, and are pulled down. 
     The roller unit 6 continues descending as indicated by arrow D in FIG. 20. The descending amount depends on a wire length to be determined. The pinch roller 13 advances the full distance forward parallel to the axis of roller 13, and the pinch roller unit 10 starts rising as indicated by arrow E. 
     First, all wires W1 to W5 are lowered to a lowest level corresponding to the longest length L1 by the roll 9. Before starting the longest length wire measurement subsequent to the pulling-down of all wires to the lowest level, the swingable arm 12 rotates inward as indicated by arrow F in FIG. 21 to permit the pinch roller 13 to invade somewhat the area between the upper and lower rollers 8 and 9 on one side of the roller unit 6. For instance, the pinch roller 13 is made to stop, exceeding one millimeter beyond the line extending tangentially along the upper and lower rollers 8 and 9 of the roller unit 6. 
     Thus, upon wire measurement, all wires W1 to W5 are kept pushed against the upper and lower rollers 8 and 9 by the pinch roller 13 on one side of the roller unit 6. 
     The inventor found that the wire measurement effected in this condition prevents the curling of wires between the lower roller 9 and the electrical connector press-connected wires ends. The pinch roller 13 is released just before completion of the wire measurement as seen from FIG. 22. Then in the same way as the first embodiment, the wire-length measuring apparatus proceeds to the subsequent step as shown in FIG. 23. 
     Referring to FIGS. 24 to 29, a wire-measuring apparatus according to a third embodiment the present invention is described below. It is a modification of the first embodiment, and is appropriate for the purpose of measuring different wire lengths. Specifically, when the lower roller 9 starts rising for measuring a subsequent shorter wire length sequential to completion of a preceding wire measurement, and when some wires selected to be measured subsequently are withdrawn toward the wire supply reels 1, the pinch roller 15 is put in contact with the upper roll 8 to push the selected wire which are being pulled back. 
     As is the case with the first or second embodiment, electric connector R is press-connected to the right ends of all wires W1 to W5, and then, the so press-connected electric connector R is carried in the right direction A by the electric connector carrier 3. After the feeding of all wires W1 to W5 stops, the wire supply rolls 1 are rotated counterward to pull all wires W1 to W5 backward, thereby stretching these wires under tension. In this condition the roll unit 6 remains as the upper, original position whereas the pinch roll unit 10 remains at the lower, original position, keeping its swingable arms 12 and 14 open, and hence keeping the pinch rollers 13 and 15 withdrawn. 
     Then, the roller unit 6 is lowered to cause all wires W1 to W5 to yieldingly descend as indicated at B in FIG. 25, thus starting the wire measurement. Specifically, all wires W1 to W5 are fitted in the circumferential grooves 17 of the lower roller 9, and are pulled down. 
     The roller unit 6 descends further as indicated by arrow D in FIG. 26. The descending amount depends on the wire length to be determined. The pinch roller 13 advances full distance forward, and the pinch roller unit 10 starts rising as indicated by arrow E. 
     Assume that two wires W4 and W5 are to be the longest length L1 and that three wires W1, W2 and W3 are to be a second shorter length L2. First, all wires W1 to W5 are lowered to a lowest level corresponding to the longest length L1 by the roller 9. Before completing the longest length wire measurement, only the swingable arm 12 rotates inward as indicated by arrow F in FIG. 27 to permit the pinch roller 13 to invade somewhat the area between the upper and lower rollers 8 and 9 on one side of the roller unit 6. Thus, all wires are pushed against the upper and lower rollers 8 and 9 by the pinch roller 13. At this time, the other pinch roller 15 remains spaced apart from the roller unit 6. Just before completion of the longest wire measurement the pinch roller 13 is withdrawn as indicated by arrow G in FIG. 28. 
     When the second longest wire measurement is performed on the wires W1 to W3, the lower rollers 9 of the roller unit 6 rises to a level corresponding to the second longest length L2 as indicated by arrow J in FIG. 29. Then, the wires W1 to W3 are withdrawn toward the wire supply reels 1 as indicated by arrow K to determine the second longest length L2. During this withdrawal the pinch roller 15 is moved into contact with the upper roller 8, pushing the withdrawn wires W1 to W3 against the upper roller 8. Thus, the curling of these wires are prevented. The apparatus otherwise works sequentially in the same way as the first embodiment. 
     As may be understood from the above, the wires to be measured can be advantageously prevented from curling in the course of measurement.