WO1990011636A1

WO1990011636A1 - Method of termination of an insulated wire

Info

Publication number: WO1990011636A1
Application number: PCT/US1990/001226
Authority: WO
Inventors: Incorporated Amp
Original assignee: Whelan, Michael, Joseph, Gerard
Priority date: 1989-03-29
Filing date: 1990-03-07
Publication date: 1990-10-04
Also published as: GB8907038D0

Abstract

A method of terminating a wire (2) having a fiberglass outer sleeve of insulation (4) provided thereabout is described. The wire is positioned between wire clamping devices (14) and insulation engagement members (16). The members (14, 16) are placed in engagement with the wire (2) in such a manner so as to displace the outer sleeve (4) of the wire away from the end (18) of the wire. The displacement of the outer sleeve (4) provides a termination area on the wire, to which an insulation displacement contact (10), or the like, can be terminated.

Description

METHOD OF TERMINATION OF AN INSULATED WIRE The invention is directed to a method for the reliable termination of an electrical wire to an electrical terminal. In particular, an outer sleeve of insulation of the wire is moved from the termination zone, so that the electrical terminal can cooperate directly with the conductor of the electrical wire.

There are many known ways to terminate an electrical wire to an electrical terminal. One of the most common ways is to use insulation displacement contacts (IDC) . In general, these methods perform adequately when a standard wire is used which has standard insulation provided thereabout. However, wires which have special insulation present special problems when the wire is to be terminated to the electrical terminal.

An example of an insulated wire which is difficult to terminate is a fiberglass sleeved, silicone (or PVC) insulated wire. The reason that the termination is difficult is due to the fact that the insulation provided about the conductor is mechanically difficult to strip. In this particular case, the stripping of the insulation is not consistent, because the laminated, resin bonded structure of the outer sleeve does not behave homogeneously, and the compliant nature of the insulation does not provide the reactive forces required during stripping.

It should also be noted that the effective use of conventional stripping tools with such type of insulated wires is minimized. Due to the characteristics of the insulation material, conventional stripping tools are subject to increased wear when used to strip the insulation. This results in the fraying of the stripped wire, which in turn decreases the performance of the termination. The use of the fiberglass sleeve, silicone insulated wire (which is normally used when the wire is subjected to high temperature) is particularly ineffective when the wire is to be terminated to IDC technology. This is due to the fact that the outer sleeve does not experience plastic flow, and therefore, the ID contact will not always be placed in electrical engagement with the conductor of the wire.

It would therefore prove beneficial to provide a method to terminate wires, in which the insulation sleeve of the wires was displaced, so that the termination of the contact to the conductor could be insured. This would result in a much more effective, and reliable interconnection. The invention is directed to a method of terminating an electrical wire to an electrical terminal. The electrical wire has a sleeve of insulation provided about an inner core.

The method involves the steps of clamping the wire to prevent movement of the wire in a direction along the longitudinal axis of the wire. Moving the sleeve of insulation of the wire away from an end of the wire, thereby exposing the inner core of the wire. And terminating the inner core of the wire to the electrical terminal.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a perspective view of a conductive wire having an insulation sleeve extending about conductors thereof;

FIGURE 2 is a diagrammatic view showing the wire inserted into a connector, the wire being in a preterminated position; FIGURE 3 is a diagrammatic view similar to Figure 2, showing a first member of the insulation displacement means placed in engagement with the wire;

FIGURE 4 is a diagrammatic view similar to Figure 3, showing a second member of the insulation displacement means placed in engagement with the wire;

FIGURE 5 is a diagrammatic view similar to Figure

4, showing the second member moved toward the first member, causing the insulation of the wire to be displaced, allowing the wire to be terminated to a terminal provided in the connector; and

FIGURE 6 is a diagrammatic view similar to Figure

5, showing the first member moved away from the wire, and the insulation of the wire returned toward its original position.

Referring to Figure 1, a high temperature wire 2 is shown. The wire 2 has an outer fibrous sleeve 4, an inner insulation layer 6, and conductors 8. The outer fibrous sleeve 4 is made from resin bonded laminate, or any other materials which are able to withstand the high temperature associated with the wire, while maintaining the electrical characteristics required. The inner insulation layer 6 is manufactured from silicone or the like. Wires of this type are commonly available in the market.

In order for the wire 2 to be utilized, it is essential that the wire 2 be terminated to a contact 10 of an electrical connector 12, in such a manner so as to insure that the conductors 8 of the wire 2 are placed in electrical engagement with the terminal 10 of the connector 12. However, as was previously stated, the termination of the insulated wire 2 is complicated, due to the fact that the stripping and penetration of the outer sleeve 4 is mechanically difficult. This is particularly true when the wire 2 is to be terminated to the connector 12 which has insulation displacement terminal 10 provided therein.

Consequently, in order to facilitate the termination of wire 2, and to insure that a positive electrical connection is effected between the conductors 8 and the terminal 10, an insulation moving device is utilized during the termination process. This device can be incorporated within the application tooling which is used to terminate the wire to the contact. In order to facilitate the understanding of the method of termination of the wire, a brief overview of the method will be given before the detailed explanation is presented. As shown in Figure 2, the wire 2 is moved into proximity with the insulation moving device. The device engages the wire, and causes the outer sleeve 4 to be pushed away from the point of termination, thus exposing the inner insulation layer 6 of the wire 2. The exposed insulation layer 6, with the conductors 8 provided therein, can then be effectively terminated by the conventional means of insulation displacement or any other known means of termination. Once termination is effected, the device is withdrawn from the outer sleeve, thereby allowing the outer sleeve 4 to return toward its original position. However, as shown in Figure 6, the outer sleeve cooperates with the terminal 10, to prevent the outer sleeve 4 from returning to its original position. The termination of the wire is completed, and an effective reliable interconnection is provided.

To provide a more complete understanding of the method of termination, a detailed description of Figures 2 through 6 will now be provided. As shown in Figure 2, the electrical connector 12, with at least one terminal 10 provided therein, is positioned proximate the insulation moving device. The insulation moving device has wire clamping members 14 and insulation engagement members 16. A respective wire 2 is moved between members 14, 16 so that one wire clamping member 14 and one insulation engagement member 16 are positioned above the wire 2, as shown in Figure 2, and the other members 14, 16 are provided below the wire. It is worth noting that in this preassemble position, an end 18 of the wire 2 is provided in the connector 12, but is not terminated to the terminal 10.

Referring now to Figure 3, the wire clamping members 14 are moved toward each other. This movement is continued until ends 20 of the wire clamping members 14 are placed in engagement with the wire 2. It is important that the movement of the wire clamping members 14 toward each other be continued until a sufficient force is applied to the wire 2 to prevent the wire 2 from being moved in a direction along the longitudinal axis of the wire. However, it is also important to note that the force applied to the wire should not be of such magnitude so as to damage the conductors 8 of the wire 2. Therefore, it is important that the movement of the wire clamping members 14 be accurately controlled. With the wire 2 secured in position by wire clamping members 14, insulation engagement members 16 are moved into engagement with wire 2, as is shown in Figure 3. Insulation engagement members 16 are positioned between connector 12 and wire clamping members 14. It is important to note, that the insulation engagement members 16 do not exert the same amount of force on the wire as do the wire clamping members. In other words, ends 22 of members 16 are not moved as far as ends 20 of members 14. The controlled movement of ends 22 of insulation engagement members 16 insures that the ends 22 will engage only the outer sleeve 4 of insulation of wire 2.

Referring to Figure 5, with the wire clamp members 14 and insulation engagement members 16 positioned in engagement with the wire 2, insulation engagement members 16 are moved toward wire clamp members 14. As the insulation engagement members 16 cooperate with the outer sleeve 4, the movement of the members 16 causes the outer sleeve 4 to move toward wire clamp members 14 as shown in Figure 5. This movement causes the outer sleeve 4 to be moved from the end 18 of the wire 2, leaving the inner insulating layer 6 and the end of the conductors 8 exposed. The connector 12 is then moved upward, relative to the wire, such that the terminal 10 engages the inner insulating layer 6 and the conductors 8. As the terminals are of the insulation displacement type, the termination of the conductors 8 to the terminals 10 results in a reliable interconnection therebetween. After the termination of the wire 2 to the terminal 10 is complete, the insulation engagement members 16 are withdrawn, as shown in Figure 6. This allows the outer sleeve 4 to return toward its original, unstressed position. In the alternative, members 16 could be displaced toward connector 12 prior to retraction, thereby causing the displacement of the outer sleeve back toward its original position. However, as the terminal is positioned at the end 18 of the wire 2, the outer sleeve 4 of the wire is not able to return to its original position, but is rather forced against the terminal 10, as is shown in Figure 6.

The wire clamp members 14 are then removed from the wire 2. The wire can then be clamped to provide an effective strain relief, thereby protecting the integrity of the electrical connection provided between the terminal 10 and the wire 2.

Several important advantages are provided by the method of termination of the present invention. First, the method utilized eliminates the need to cut or conventionally strip the wire of the outer sleeve. As was early discussed, many problems are encountered when a fiberglass sleeved insulated wire is to be cut or stripped. The present invention eliminates these problems.

A second advantage of the present invention relates to its use with harness manufacturing technology. As the termination method described may be accomplished within the termination cycle time, the method is well suited for use with harness makers. Also, as the method described produces no debris, consequently, the use of the method in harness making is made more feasible.

A third advantage of the method described relates to its ease of implementation. This method does not require complex heating and/or fusion of the fiberglass sleeve, which is sometimes required. Therefore, the equipment needed to utilize this invention can be easily incorporated into the application tooling required for assembly.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting.

Claims

CIAIHS :

1. A method of terminating an electrical wire (2) to an electrical terminal (10) , the electrical wire (2) having a sleeve (4) of insulation provided about an inner core (6,8), the method comprising the steps of: clamping the wire (2) to prevent movement of the wire in a direction along the longitudinal axis of the wire; moving the sleeve (4) of insulation of the wire (2) away from an end (18) of the wire (2) , thereby exposing the inner core (6,8) of the wire (2); and terminating the inner core (6,8) of the wire (2) to the electrical terminal (10) .

2. A method as recited in claim 1 further characterized in that a clamping means (14,16) is provided to clamp the wire (2) and to move the sleeve (4) relative to the inner core (6,8), the clamping means (14,16) has a first clamping member (16) and a second clamping member (14) .

3. A method as recited in claim 2 further characterized in that the second clamping member (14) engages the wire (2) prior to the first clamping member (16) , thereby insuring that the second clamping member (14) will retain the wire (2) in position as the first clamping member (16) is moved into cooperation with the wire (2) .

4. A method as recited in claim 3 further characterized in that the first and the second clamping members (16,14) move in a direction which is essentially perpendicular to the longitudinal axis of the wire (2) , the second clamping member (14) is moved nearer to the longitudinal axis of the wire (2) than is the first clamping member (16) , thereby insuring that the second clamping member will prevent the wire (2) from moving relative thereto.

5. A method as recited in claim 4 further characterized in that the first clamping member (16) is movable relative to the second clamping member (14) in a direction which is essentially parallel to the longitudinal axis of the wire (2) , thereby allowing the sleeve (4) to be moved away from the end (18) of the wire (2) .

6. A method as recited in claim 1 further characterized in that the sleeve (4) of insulation provided about the wire (2) is of a laminated, resin bonded structure.

7. A method as recited in claim 6 further characterized in that the sleeve (4) is made of a fiberglass material.

8. A method as recited in claim 6 further characterized in that the sleeve (4) is made of a silicone material.