IES79059B2 - Cable harness production apparatus - Google Patents

Abstract

A production system (1) has workstations (2), each having a bench (3) with a movable service rail (4). Each service rail (4) is movable to allow very quick configuration of the system (1). Production apparatus at the workstations includes tools for stripping cable jackets, for unravelling individual wires (61), for stripping insulation by heating (71) and for applying connectors (104) and for applying a protective sleeve (111).

Description

“Cable Harness Production Apparatus” The invention relates to the production of cable harnesses, and particularly apparatus to allow versatile and efficient harness production.

Particular aspects of production of cable harnesses are that raw material handling is difficult because some components are very small and cables by their nature do not lend themselves to automated handling. However, some systems such as those described in European Patent Specification No. EP0773610 (Stocko) and United States Patent Specification No. US5016345 (Mecanismos Auxiliaries) have been devised to minimise operator handling and improve efficiency. It appears that these systems would achieve these benefits in situations where there are relatively high volumes of a particular harness product and change-over from one product to another is infrequent, but not with low volumes and frequent product changes.

There is therefore a need for a cable harness production system having apparatus or tools which provide for efficient production, while at the same time being flexible so that it can be quickly re-configured for production of different harness products without loss of efficiency.

According to the invention, there is provided production apparatus for manufacture of cable harnesses, the apparatus comprising:means for cutting cable lengths; an unravelling tool comprising a pair of cylinders mounted on supports which are movable between an open position and a closed position at which the cylinders are spaced-apart by a pre-determined distance for unravelling of twisted cables drawn between the cylinders; -2a sleeve stripping tool comprising a pair of heated blades mounted on supports movable between open and closed positions, the blades being spaced-apart in the * closed position by a distance slightly greater than the conductor diameter whereby the blades heat insulation and allow the insulation to be drawn off the conductors * as the cables are pulled through the tool; and means for connecting cable ends to connectors.

In one embodiment, the sleeve stripping tool comprises a controller having means for heating the blades to approximately 350°C.

Preferably, the stripping tool further comprises a fume extractor mounted above the blades.

In one embodiment, the apparatus further comprises means for heating a protective sleeve to shrink around a cable jacket end.

The invention will be more quickly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:Figs. 1 to 10 inclusive are diagrams illustrating production apparatus in use for production of cable harnesses.

Referring to the drawings, various production apparatus forming part of the workstations are described in operation. The apparatus is described in the context of a production flow, for ease of understanding. Referring initially to Fig. 1, a step 10 of cutting cable is ► illustrated. A reel 11 is mounted on a support (not shown) from which cable 12 is drawn to a guide 13 and to a cutter 14. This arrangement is used to produce a batch of cables of * a specific length for a harness product. After cutting, quality control checks are -3performed to ensure that all cables are the correct length, none are damaged, and all wires « are correct.

* In step 20 illustrated in Fig. 2, a jacket stripping tool 21 is used. The tool 21 comprises a base 22 supporting a pair of pivoted arms 23 which in turn support angled jaws 24. The jaws 24 are configured to cut through the insulating jacket of the cable without damaging the individual cables or wires inside. The jacket is indicated by the numeral 26 and the wires by the numeral 27. It will be appreciated that this is a very simple and effective way of stripping the jacket from cables as the jaws 24 may be easily replaced for cables of different sizes, allowing the tool 21 to be used in a universal manner for a wide variety of different harness products. Alternatively, a number of tools 21 may be provided as they are quite compact. After jackets have been stripped from a batch quality control checks are carried out to ensure that all strip lengths are correct, there is no nicked insulation, jacket foil is not removed from remaining jacket, and wires are not broken or damaged.

Referring to Fig. 3, a step 30 of unravelling cables is illustrated. This step is important as it aligns the individual cables within the jacket in a single plane so that they can be easily worked upon for subsequent production stages. An unravelling tool 31 is used, which comprises a base 32, a pair of pivoting arms 33, each supporting a cylinder 34. A drive (not shown) is used to pivot the arms to a position spaced-apart by a pre-determined distance. When an operator draws the individual cables or wires 35 between the cylinders 34, they are drawn into alignment. Again, this is a very simple tool to allow unravelling of the wires to simplify downstream processing steps. The tool 31 may be f quickly configured for a wide variety of different types of cable with different numbers of individual cables or wires and different thicknesses. After performing the step 30, the , operator performs quality control checks to determine if the wires are correctly unravelled and if there has been any damage to insulation. -4Referring to Fig. 4, a step 40 of stripping insulation from individual cables or wires is illustrated. An apparatus 41 is used which comprises cables 42 interconnecting a » controller 43 and heated blades 44. The blades 44 are blunt, being approximately 1mm wide at the connect side edges. A fume extractor 46 is mounted above the blades 44. As ' shown in Fig. 4, individual cables 45, which have been previously aligned by the unravelling tool 31 are placed between the blades 44, the blades then being moved inwardly to a position at which they are separated by approximately 0.2mm greater than the diameter of the wire conductors. This level of heating of the sleeves when the blades are at a temperature of 350°C allows the sleeves to be easily drawn from the conductors as the set of wires is pulled through the apparatus 41. It will be appreciated that this is a very simple and effective way of stripping insulating sleeves from a number of cables together. Because a number of cables are stripped simultaneously, the step is very efficient. Also, because heated blades are used, there is a low risk of damage to the conductors. Also, the heating of the insulation allows for very quick sleeve stripping for high efficiency. The quality control checks which are carried out by operator at this stage include checking the stripped length, checking for nicked insulation, and checking for broken or damaged conductors.

As shown in Fig. 5 a step 50 is then performed with a cable 51 having individual cables or wires 52 including a drain wire 53 which is not insulated. A drain wire sleeve 54 is fitted over the drain wire 53. As shown in the cross-section I -1, the jacket comprises an outer insulating sleeve 56 and an inner foil 57. The foil 57 is in contact with the drain wire 53 to provide an earth leakage path. In step 60 as illustrated in Fig. 6, a protective sleeve 61 is fitted over the cable at the position at which the individual wires extend from the jacket 55. When the operator has performed the steps 50 and 60, he or she performs quality control checks including checking for blisters on the wire insulation, checking that the protective sleeve is not too tight on the jacket, and checking that the protective sleeve is not damaged. -5Referring now to Fig. 7, a step 70 of applying connectors to exposed conductors at the end of wires is illustrated. A conductor 71 receives the end of a wire 72 and crimps it using crimping leads 73. This operation is performed using a connectorising machine 74 having a cartridge 75 which moves step-wise inwardly to connect successive pairs of wires 72. After performing this step, the operator checks for the following faults:wrong wire, damaged terminal, short/long wire, reversed wire, damaged wire/insulation, reversed connector, popped contact, incorrect wire depth, damaged/insecure tab, open/damaged strain relief, damaged connector, and sleeve not tied to jacket. -6This is a comprehensive set of checks to ensure quality at this production stage.

In step 80, the protective sleeve is heat shrinked around the cable as illustrated in Fig 8. A hot air blower 81 is used. After the protective sleeve has been heat shrunk, the operator performs a quality control check to ensure that the sleeve is in the correct position, that it is fully shrunk around the cable, that the sleeve is not missing, that the sleeve is not split or damaged, and that there is no blister on the cable insulation. In step 90, the harness 91 is labelled with a label 92 secured around it.

Finally, in step 100, the harness 91 is tested using a test apparatus 101. The apparatus 101 comprises a controller 102 having displays 103 and test signal cables 104 connecting it with a test fixture 105. The fixture 105 has sockets 106 to receive the connectors at the ends of the harness 91. The operator inserts the connectors into sockets 106 and then activates the controller 102, which transmits various signals to pins of the sockets 106 to perform continuity and high voltage tests.

It will be appreciated that the invention provides a production apparatus which may be used in a very simple and flexible manner for a production of a wide range of harness products with a short set-up time and high efficiency.

The invention is not limited to the embodiments described, but may be varied in construction and detail within the scope of the claims.

Claims (1)

1. Production apparatus for manufacture of cable harnesses, the apparatus comprising:means for cutting cable lengths; an unravelling tool comprising a pair of cylinders mounted on supports which are movable between an open position and a closed position at which the cylinders are spaced-apart by a pre-determined distance for unravelling of twisted cables drawn between the cylinders; a sleeve stripping tool comprising a pair of heated blades mounted on supports movable between open and closed positions, the blades being spaced-apart in the closed position by a distance slightly greater than the conductor diameter whereby the blades heat insulation and allow the insulation to be drawn off the conductors as the cables are pulled through the tool; and means for connecting cable ends to connectors. Production apparatus as claimed in claim 1, wherein the sleeve stripping tool comprises a controller having means for heating the blades to approximately 350°C. Production apparatus as claimed in claims 1 or 2, wherein the stripping tool further comprises a fume extractor mounted above the blades. Production apparatus as claimed in any preceding claim, further comprising means for heating a protective sleeve to shrink around a cable jacket end. -8Production apparatus substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.