GB2160028A

GB2160028A - Wiring loom

Info

Publication number: GB2160028A
Application number: GB08414460A
Authority: GB
Inventors: David Harry Johnson
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1984-06-06
Filing date: 1984-06-06
Publication date: 1985-12-11
Also published as: GB2160028B; GB8414460D0

Abstract

A method is described for making a wiring loom wherein the wires to form the wiring loom are placed in a former 10, and a foamed plastics material is injected into the former about the loom wires to encapsulate the latter. Prior to encapsulation the wires may be taped; after encapsulation the former is removed. The foamed plastics may be thickened at points where the loom might rattle or become worn (Fig 4). The Wires may be encapsulated along all or only part of their length. <IMAGE>

Description

SPECIFICATION Wiring loom The present invention relates to a wiring harness or loom for use, for example, in a motor vehicle.

It is conventional in motor vehicles to bind the bundle of wires which estabish the various necessary connections into a loom by wrapping the bundle in tape. The loom tends in some places to rattle against the body of the vehicle and it is known to encase the wrapped loom in a split sleeve of foamed material to reduce noise and prevent ware.

The present invention seeks to provide an improved loom and method of making a wiring loom which is simpler and thus less expensive to construct and which provides increased protection to the individual wires in the loom.

In accordance with a first aspect of the invention, there is provided a method of making a wiring loom wherein the wires to form the wiring loom are placed in a former and a foamed plastics material is injected into the former about the loom wires to encapsulate the latter.

The wires may be taped or untaped prior to being inserted into the former. If the loom is untaped then the foamed plastics material serves the dual function of a binder for keeping the individual wires in a single loom and of protecting the loom at points where rattling may occur after installation in a vehicle.

The thickness of the foamed plastics encapsulation need not be uniform and it is preferred to provide an increased thickness at rattle points.

The former is preferably split longitudinally so that it may be assembled about the loom wires and separated after the plastics material has set to permit withdrawal of the encapsulated loom.

To seal the ends of the former about the wires during the injection of the plastics material, an adjustable shutter may be incorporated into the former at each end, construted in the manner of an iris of a photographic camera, or, more simply, a grommet, preferably a split grommet may be placed about the wires prior to their being placed in the former.

The former may comprise two hinged halves or two separable halves. In the latter case, the amount of overlap between the two halves may be adjustable to vary the size of the encapsulated loom.

In a further aspect of the invention, there is provided a wiring loom for a vehicle comprising a plurality of wires encapsulated within a foamed plastics material.

Preferably the sleeve serves both to bind the individual wires of the loom and to protect the loom wires against ware. Alternatively, the wires may be bound with tape prior to their being encapsulated in the foamed plastics material.

If the wires are unbound, the loom has the advantage over conventional taped looms that the encapsulation may be cut to permit a single wire to be withdrawn for repair or replacement without at the same time unbinding the entire bundle of wires in the loom.

The invention will now be described further by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a schematic diagram of one end of a former for encapsulating wires in a foamed plastics material, Figure 2 is a schematic perpective view of a split grommet for use in sealing the end of the former during the course of injection, Figure 3 is a first section through a wire loom in which the plastics material serves only to bind the wires in the loom, Figure 4 is a similar second section through the loom at a point where the loom is to be protected against rattling, and Figure 5 shows schematically an alternative type of former suitable for looms of different sizes.

Figure 1 is a partial perspective view of a former 10 for encapsulating the wires of a loom in a foamed plastics material. The former 10 comprises two halves 10a and 10b hinged to one another along a line 12. Each end of the former 10 is formed with a locating rib 14 and an injection nozzle 16 enable a plastics material to be injected into the former.

In use, a section of a wiring loom is inserted into the former 10. A split grommet 20, as shown in Figure 2, is placed around the loom at each end of the former 10 and is held in position by the rib 14 of the former engaging a corresponding groove 22 in the grommet 20. The former halves are now pivoted to close around the loom wires and a plastics material is injected through the nozzle 16 into the space surrounding the wires of the loom. The resultant encapsulated loom is shown in section in Figure 3. Here, the wires are encased in just sufficient thickness of foamed plastics material to bind the wires to each other, thus obviating the need for taping.

At rattle points, the section of the loom is as shown in Figure 4 where the increased thickness of the foamed plastics material serves additionally to provide cushioning to protect the wires and to prevent noise and ware.

In Figure 5, an alternative type of former 50 is shown which comprises totally separable halves 50a and 50b which may be slid relative to each other as represented by the arrows to vary the amount of overlap. This enables the cross sectional area to be varied to suit different thicknesses of loom.

The wires of the loom in Figures 3 and 4 are shown untaped but it is alternatively possible to wind tape around the wires prior to their encapsulation in the foamed plastics material.

The wires of the loom may be encapsulated in a foamed plastics material along their entire length but alternatively only some sections of the loom need be protected in this manner.

1. A method of making a wiring loom wherein

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Wiring loom The present invention relates to a wiring harness or loom for use, for example, in a motor vehicle. It is conventional in motor vehicles to bind the bundle of wires which estabish the various necessary connections into a loom by wrapping the bundle in tape. The loom tends in some places to rattle against the body of the vehicle and it is known to encase the wrapped loom in a split sleeve of foamed material to reduce noise and prevent ware. The present invention seeks to provide an improved loom and method of making a wiring loom which is simpler and thus less expensive to construct and which provides increased protection to the individual wires in the loom. In accordance with a first aspect of the invention, there is provided a method of making a wiring loom wherein the wires to form the wiring loom are placed in a former and a foamed plastics material is injected into the former about the loom wires to encapsulate the latter. The wires may be taped or untaped prior to being inserted into the former. If the loom is untaped then the foamed plastics material serves the dual function of a binder for keeping the individual wires in a single loom and of protecting the loom at points where rattling may occur after installation in a vehicle. The thickness of the foamed plastics encapsulation need not be uniform and it is preferred to provide an increased thickness at rattle points. The former is preferably split longitudinally so that it may be assembled about the loom wires and separated after the plastics material has set to permit withdrawal of the encapsulated loom. To seal the ends of the former about the wires during the injection of the plastics material, an adjustable shutter may be incorporated into the former at each end, construted in the manner of an iris of a photographic camera, or, more simply, a grommet, preferably a split grommet may be placed about the wires prior to their being placed in the former. The former may comprise two hinged halves or two separable halves. In the latter case, the amount of overlap between the two halves may be adjustable to vary the size of the encapsulated loom. In a further aspect of the invention, there is provided a wiring loom for a vehicle comprising a plurality of wires encapsulated within a foamed plastics material. Preferably the sleeve serves both to bind the individual wires of the loom and to protect the loom wires against ware. Alternatively, the wires may be bound with tape prior to their being encapsulated in the foamed plastics material. If the wires are unbound, the loom has the advantage over conventional taped looms that the encapsulation may be cut to permit a single wire to be withdrawn for repair or replacement without at the same time unbinding the entire bundle of wires in the loom. The invention will now be described further by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a schematic diagram of one end of a former for encapsulating wires in a foamed plastics material, Figure 2 is a schematic perpective view of a split grommet for use in sealing the end of the former during the course of injection, Figure 3 is a first section through a wire loom in which the plastics material serves only to bind the wires in the loom, Figure 4 is a similar second section through the loom at a point where the loom is to be protected against rattling, and Figure 5 shows schematically an alternative type of former suitable for looms of different sizes. Figure 1 is a partial perspective view of a former 10 for encapsulating the wires of a loom in a foamed plastics material. The former 10 comprises two halves 10a and 10b hinged to one another along a line 12. Each end of the former 10 is formed with a locating rib 14 and an injection nozzle 16 enable a plastics material to be injected into the former. In use, a section of a wiring loom is inserted into the former 10. A split grommet 20, as shown in Figure 2, is placed around the loom at each end of the former 10 and is held in position by the rib 14 of the former engaging a corresponding groove 22 in the grommet 20. The former halves are now pivoted to close around the loom wires and a plastics material is injected through the nozzle 16 into the space surrounding the wires of the loom. The resultant encapsulated loom is shown in section in Figure 3. Here, the wires are encased in just sufficient thickness of foamed plastics material to bind the wires to each other, thus obviating the need for taping. At rattle points, the section of the loom is as shown in Figure 4 where the increased thickness of the foamed plastics material serves additionally to provide cushioning to protect the wires and to prevent noise and ware. In Figure 5, an alternative type of former 50 is shown which comprises totally separable halves 50a and 50b which may be slid relative to each other as represented by the arrows to vary the amount of overlap. This enables the cross sectional area to be varied to suit different thicknesses of loom. The wires of the loom in Figures 3 and 4 are shown untaped but it is alternatively possible to wind tape around the wires prior to their encapsulation in the foamed plastics material. The wires of the loom may be encapsulated in a foamed plastics material along their entire length but alternatively only some sections of the loom need be protected in this manner. CLAIMS

1. A method of making a wiring loom wherein the wires to form the wiring loom are placed in a former and a foamed plastics material is injected into the former about the loom wires to encapsulate the latter.

2. A method as claimed in claim 1, wherein the wires are not wound in tape prior to encapsulation, the foamed plastics material serving to bind the wires together.

3. A method as claimed in claim 1 or 2, wherein the thickness of the foamed plastics material is not be uniform, the thickness being increased at rattle points.

4. A method as claimed in any preceding claim, wherein the former is split longitudinally, the former being assembled about the loom wires and separated after the plastics material has set to permit withdrawal of the encapsulated loom.

5. A method as claimed in claim 4, wherein in order to seal the ends of the former about the wires during the injection of the plastics material a split grommet is placed about the wires prior to their being placed in the former.

6. A wiring loom for a vehicle comprising a plurality of wires encapsulated within a foamed piastics material.

7. A wiring loom as claimed in claim 6, wherein the foamed plastics material serves both to bind the individual wires of the loom and to protect the loom wires against ware.

8. A wiring loom as claimed in claim 6, wherein the wires are bound with tape prior to their being encapsulated in the foamed plastics material.

9. A method of making a wiring loom, substantially as herein described with reference to and as iilustrated in the accompanying drawings.