GB2195064A

GB2195064A - Fuseboards

Info

Publication number: GB2195064A
Application number: GB08621777A
Authority: GB
Inventors: Kevin Trevor Talbot
Original assignee: Salplex Ltd
Current assignee: Salplex Ltd
Priority date: 1986-09-10
Filing date: 1986-09-10
Publication date: 1988-03-23
Also published as: GB8621777D0

Abstract

A fuseboard comprises a printed circuit board in which an insulating board (1) has printed copper tracks (2) across its width. Fuseholders, each consisting of a pair of contacts (4A and 4B) adapted to hold a cartridge fuse (5), are attached to the board (1) each in electrical contact with a respective one of the tracks (2). Each track (2) thus connects the pair of contacts (4A and 4B) of a respective fuseholder and has a narrow width portion (2A) whose width is chosen such that it is fusible at a predetermined current. Thus when a fusebox is first built incorporating the fuseboard described there is no need to fit cartridge fuses (5) in the fuseholders. The thin width portion (2A) of each track (2) initially serves as a fuse element without a cartridge fuse in the respective holder (4A, 4B). When a fuse element (2A) blows a cartridge fuse (5) may be plugged in to replace it. <IMAGE>

Description

SPECIFICATION Fuseboards This invention relates to fuseboards and to fuseboxes including fuseboards, for example for use in automotive vehicle electrical systems.

Fuseboards are known comprising an insulating board and a plurality of fuseholders attached to the board, each fuseholder consisting of a pair of contacts adapted to hold a cartridge fuse.

Although the cost of providing each cartridge fuse and inserting it into its fuseholder during manufacture of a system incorporating the fuseboard is small, the total cost in manufacture of very large scale mass produced systems, for example automotive vehicle electrical ssytems can be significantly large.

An object of this invention is to reduce the cost in manufacture just described.

According to the present invention there is provided a fuseboard as described in the second paragraph of this specification, characterised in that a plurality of printed circuit tracks are provided on the board, each said track connecting the pair of contacts of a respective fuse holder and being fusible at a predetermined current. Thus each said track may initially serve as a fuse element without a cartridge fuse in the respective holder and may be substituted by a cartridge fuse in the respective holder when that track is severed.

The insulating board may be made of a heat resistant material capable of withstanding the heat generated when a said track fuses. Alternatively, the insulating board may be laminated with a heat resistant material under each said track.

A fuseboard according to the invention may have a brightly coloured area provided under each said track which is revealed when that track is severed. This aid to visual identification of a severed fuse track can be helpful in fault diagnosis of the electrical system of which the fuseboard forms a part either during manufacture of that system or afterwards by the user of that system.

According to the invention there is also provided an automotive vehicle electrical system fusebox including a fuseboard according to the invention. Such a fusebox may advantageously bear instructions to the effect that a cartridge fuse is not to be inserted unless to replace a severed fusetrack.

An example of a fuseboard according to the invention is described below with reference to the accompanying drawings in which, Figure 1 shows a plan view of the fuseboard with a cartridge fuse inserted in place of a severed fusetrack, and Figure 2 shows a section view on the line A-A of Fig. 1.

Referring now to the drawings a fuseboard comprises a printed circuit board in which an insulating board 1 has six printed copper tracks 2 across its width. Six fuseholders, each consisting of a pair of contacts 4A and 4B adapted to hold a cartridge fuse, are attached to the board 1 each in electrical contact with a respective one of the tracks 2.

Each track 2 thus connects the pair of contacts 4A and 4B of a respective fuseholder and has a narrow width portion 2A whose width is chosen such that it is fusible at a predetermined current.

The insulating board 1 may be made of a heat resistant material capable of withstanding the heat generated when a track portion 2A fuses. Alternatively, the insulating board 1 may be made of a conventional printed circuit board material which is laminated with a heat resistant material under each track portion 2A.

The heat resistant lamination may take the form of a single strip 3 along the length of the board 1 under all the track portions 2A.

Thus when a fusebox is first built incorporating the fuseboard just described there is no need to fit cartridge fuses in the fuseholders.

The thin width portion 2A of each track 2 initially serves as a fuse element without a cartridge fuse in the respective holder 4A, 4B.

When a fuse element 2A blows a cartridge fuse may be plugged in to replace it. One such cartridge fuse 5 is shown in Fig. 1.

A brightly coloured area (not shown in the drawings) may be provided under each fuse element 2A which is revealed when that track is severed either because the fuse has blown or has been cut away.

The fusebox incorporating the fuseboard may bear instructions to the effect that a cartridge fuse is not to be inserted unless to replace a severed fuse track 2A An intended use of the fuseboard and fusebox described above is in automotive vehicle electrical systems. They can be used in other electrical systems, for example industrial control systems such as for heating and ventilation.

1. A fuseboard comprising an insulating board and a plurality of fuse holders attached to the board, each fuseholder consisting of a pair of contacts adapted to hold a cartridge fuse, characterised in that a plurality of printed circuit tracks are provided on the board, each said track connecting the pair of contacts of a respective fuseholder and being fusible at a predetermined current.

2. A fuseboard as claimed in Claim 1, in which the insulating board is made of a heat resistant material capable of withstanding the heat generated when a said track fuses.

3. A fuseboard as claimed in Claim 1, in which the insulating board is laminated with a heat resistant material under each said track capable of withstanding the heat generated

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fuseboards This invention relates to fuseboards and to fuseboxes including fuseboards, for example for use in automotive vehicle electrical systems. Fuseboards are known comprising an insulating board and a plurality of fuseholders attached to the board, each fuseholder consisting of a pair of contacts adapted to hold a cartridge fuse. Although the cost of providing each cartridge fuse and inserting it into its fuseholder during manufacture of a system incorporating the fuseboard is small, the total cost in manufacture of very large scale mass produced systems, for example automotive vehicle electrical ssytems can be significantly large. An object of this invention is to reduce the cost in manufacture just described. According to the present invention there is provided a fuseboard as described in the second paragraph of this specification, characterised in that a plurality of printed circuit tracks are provided on the board, each said track connecting the pair of contacts of a respective fuse holder and being fusible at a predetermined current. Thus each said track may initially serve as a fuse element without a cartridge fuse in the respective holder and may be substituted by a cartridge fuse in the respective holder when that track is severed. The insulating board may be made of a heat resistant material capable of withstanding the heat generated when a said track fuses. Alternatively, the insulating board may be laminated with a heat resistant material under each said track. A fuseboard according to the invention may have a brightly coloured area provided under each said track which is revealed when that track is severed. This aid to visual identification of a severed fuse track can be helpful in fault diagnosis of the electrical system of which the fuseboard forms a part either during manufacture of that system or afterwards by the user of that system. According to the invention there is also provided an automotive vehicle electrical system fusebox including a fuseboard according to the invention. Such a fusebox may advantageously bear instructions to the effect that a cartridge fuse is not to be inserted unless to replace a severed fusetrack. An example of a fuseboard according to the invention is described below with reference to the accompanying drawings in which, Figure 1 shows a plan view of the fuseboard with a cartridge fuse inserted in place of a severed fusetrack, and Figure 2 shows a section view on the line A-A of Fig. 1. Referring now to the drawings a fuseboard comprises a printed circuit board in which an insulating board 1 has six printed copper tracks 2 across its width. Six fuseholders, each consisting of a pair of contacts 4A and 4B adapted to hold a cartridge fuse, are attached to the board 1 each in electrical contact with a respective one of the tracks 2. Each track 2 thus connects the pair of contacts 4A and 4B of a respective fuseholder and has a narrow width portion 2A whose width is chosen such that it is fusible at a predetermined current. The insulating board 1 may be made of a heat resistant material capable of withstanding the heat generated when a track portion 2A fuses. Alternatively, the insulating board 1 may be made of a conventional printed circuit board material which is laminated with a heat resistant material under each track portion 2A. The heat resistant lamination may take the form of a single strip 3 along the length of the board 1 under all the track portions 2A. Thus when a fusebox is first built incorporating the fuseboard just described there is no need to fit cartridge fuses in the fuseholders. The thin width portion 2A of each track 2 initially serves as a fuse element without a cartridge fuse in the respective holder 4A, 4B. When a fuse element 2A blows a cartridge fuse may be plugged in to replace it. One such cartridge fuse 5 is shown in Fig. 1. A brightly coloured area (not shown in the drawings) may be provided under each fuse element 2A which is revealed when that track is severed either because the fuse has blown or has been cut away. The fusebox incorporating the fuseboard may bear instructions to the effect that a cartridge fuse is not to be inserted unless to replace a severed fuse track 2A An intended use of the fuseboard and fusebox described above is in automotive vehicle electrical systems. They can be used in other electrical systems, for example industrial control systems such as for heating and ventilation. CLAIMS

3. A fuseboard as claimed in Claim 1, in which the insulating board is laminated with a heat resistant material under each said track capable of withstanding the heat generated when a said track fuses.

4. A fuseboard as claimed in any one of Claims 1 to 3, in which a brightly coloured area is provided under each said track which is revealed when that track is severed.

5. An automotive vehicle electrical system fusebox including a fuseboard as claimed in any preceding claim.

6. A fusebox as claimed in Claim 5 bearing instructions to the effect that a cartridge fuse is not to be inserted unless to replace a severed fuse track.