GB2388480A

GB2388480A - Cartridge fuse with multiple fuse elements

Info

Publication number: GB2388480A
Application number: GB0210549A
Authority: GB
Inventors: Russell Craig Shayer; Michael Shayer
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-05-09
Filing date: 2002-05-09
Publication date: 2003-11-12
Anticipated expiration: 2022-05-09
Also published as: GB0210549D0; GB2388480B

Abstract

A cartridge fuse comprises an elongated body 6 of insulating material 2 with end caps 1,7 adapted for contact with electrical terminals 3a,b,c, in which one end cap 7 is connected to a plurality of internal fuse elements 8,9,10, and other end cap 1 is rotatable relative to the body 6 to bring it into electrical connection with a selected one of the fuse elements 8,9,10.

Description

- 1 DESCRIPTION

Cartridge Fuse with Multiple Fuse Elements Field of the invention

The invention relates to cartridge fuses in general use with 5 most electrical appliances.

Background of the invention

Currently cartridge fuses exist as a single item per fuse rating. The end users (General public eta) have to have a selection of spare fuses of different ratings to suit their 10 electrical appliances. Often the end user does not have a fuse of the correct rating for an application and will have to either buy a new fusefs) or risk using a fuse of the incorrect rating. Because current fuses have a single fuse element they must be discarded when blown and a new 15 replacement is required Currently Retailers have to separate fuses by their ratings at the point of sale, in order to meet customer demand for each type, which is inefficient with regards to cost, time, customer coteries, shelf space / stocking etc. Currently the Wholesaler must 2O order, stock, track and distribute several types of fuse packages according to demand and availability. This requires complicated stock level control with associated cost and time penalties. Currently the Fuse manufacturer has to separate the manufacture, the packaging, stock levels and 25 shipping for each type of fuse with associated cost and time penalties due to the complexity involved.

Object of the invention An objective of this invention is to provide several 30 selectable fuse elements that may be of different or common current and / or voltage ratings within a single G=rtridge fuse. Scary of the indention 35 According to the invention, we provide a cartridge fuse comprising an elongated body of ir,slating material with end

caps adapted for contact with electrical terminals, in which: one end cap is connected to a plurality of internal fuse elements; and the other end cap is rotatable relative to the 5 body to bring it into electrical connection with a selected one of the fuse elements.

Internal fuse elements of different rating may be installed to permit choice of fuse rating for the cartridge. The fuse 10 rating selected may be indicated by the alignment of an indent in the rotatable end cap with fuse ratings indicated on the label.

Some important but not essential features of the invention: The label could be replaced by printing directly on Ike fuse body. Brief description of the drawings

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: DRAWING 1 shows End Sectional view the thorough rotatable end 25 cap with one terminal selected.

DRAWING 2 shows Side Section view through rotatable end cap with contact terminal selected.

DRAWING 3 shows Side Section view through rotatable end cap with contact terminal deselected.

30 DRAWING 4 shows Side Section view through whole cartridge fuse assembly.

Detailed description of the drawings

- 3 A cartridge fuse embodying the invention comprises an elongated hollow body (6) having a fixed end cap (7) at one end and a rotatable end cap (1) at the other end.

S A label (4) is secured to the outer surface of fuse body (6). A formed cavity in fixed end cap (7) contains solder (11) used to retain one end of three fuse elements (8,9 & 10). Terminals (3a, 3b & 3c) are soldered one to each other end of fuse elements (8,9 & 10).

Terminals (3a, 3b &3c) are mounted to fuse body (6). An end cap retainer (5) is mounted to fuse body (6). An insulator (2) is mounted within the rotatable end cap (1). A central hole in the rotatable end cap (1) is assembled over end cap 15 retainer (5) compressing terminals (3a, 3b 3c) within recesses in fuse body (I). A central pin of on the end cap retainer (5) is re-formed to retain the rotatable end cap (1) allowing free rotation of rotatable end cap (1).

20 An inwardly projecting indentation (12) in the rotatable end cap (1) makes contact, depending upon it's angular position, with one of the terminals (3a, 3b & 3c) allowing current to flow through a selected one of the fuse elements (8, & 10). An alternative fuse element (8, 9 & 10) is selected by 25 rotating the end cap from the position in which it contacts the first selected past a position in which it rides over major diameter of fuse body (6) until it locates into the required recess in the fuse body (6) connecting with the required terminal (3a, 3b or 3c). The fuse element (8, 9 or 30 10) selected is indicated by the alignment of the indent in rotatable end cap (l) with the fuse rating printed on label (4). The indent cooperates with the recesses in the fuse body to provide location in specific angular positions, each providing contact with a selected terminal.

In this particular embodiment the fuse con be re-used after it has blown by rotating the end cap to another angular

position in which the indent in the end cap is in contact with a differently rated fuse element which has not blown, therefore a single fuse can thus be re-used elsewhere until all internal fuse elements have blown.

An example of the use for the invention is in plugs on p^v.'er cables for mains powered electrical household appliances.

Alternative Tent of the invention: An alternative embodiment of the invention differs from the first embodiment in that the internal selectable fuse elements all have a common current and/or voltage rating.

In this particular embodiment the label will show a cordon 15 fuse rating for each position marked on it, and the fuse elements can he selected as described in the first embodiment by using the rotatable end cap. This means that the fuse can be re-used after it has blown by rotating the end cap to another angular position in which the indent in 20 the end cap is in contact with another fuse element which has not blown. A single fuse can thus be re-used until all internal fuse elements have blown.

2- -

Claims

- 5 CLAIMS

1. A cartridge fuse comprising an elongated body of insulating material with end caps adapted for contact with 5 electrical terminals, in which: one end cap is connected to a plurality of internal fuse elements; and the other end cap is rotatable relative to the body to bring it into electrical connection with a selected one of the fuse elements.

2. A cartridge fuse as claimed in claim 1 in which electrical connection to the selected fuse element is made via a plurality of terminal contacts, one connected to each fuse element.

3. A cartridge fuse as claimed in claim 2 having a plurality of recesses in the profile of the fuse body each arranged to accommodate a respective one of the terminal contacts.

20

4. A cartridge fuse as claimed in claim 3 in which the rotatable end cap is formed with an inwardly projecting indent which cooperates with the recesses in the fuse body to define a plurality of angular positions, in each of which angular positions the electrical connection is made to a 25 corresponding one of the fuse elements.

5. A cartridge fuse as claimed in claim 4 in which said electrical connection is made by contact between the indent and a selected terminal contact.

6. A cartridge fuse as claimed in any one of the preceding claims if! which each fuse element is of a different rating permitting choice of fuse rating for the cartridge, the selected rating being indicated by the alignment of an 35 indicator on the rotatable end cap fuse ratings indicated on a libel f red to or nera with the booty.

- 6 -

7. A cartridge fuse as claimed in claim 6, in which the fuse is reusable in the event of failure of a fuse element by rotation of the end cap to bring another.seable fuse element into contact with the rotatable end cap.

8. A cartridge fuse as claimed in claim 6 in which the indent on the end cap indicates selected fuse rating by alignment with corresponding markings on a label or on the fuse body.

9. A cartridge fuse as claimed in any one of the preceding claims in which the fuse elements are of tile same rating so that the fuse is reusable in the event of failure of a fuse element by rotation of the end cap to bring another useable 15 fuse element into contact with the rotatable end cap.

10. A hole in the rotatable end cap accommodates an axial spigot on an end cap retainer thereby securing the end cap within freedom to rotate.

11. A cartridge fuse as claimed ire any one or the preceding claims in which insulating material. within the rotatable end cap electrically insulates the non-selected fuse element or elements from the end cap.

12. A cartridge fuse as claimed in 11 in which there is an end cap retainer that attaches the rotatable end cap to fuse body.

13. A cartridge fuse as claimed in claim 12 in which the end cap retainer that insulates the fuse element terminals from the rotatable end cap.

12. A cartridge fuse as claimed in 11 in which there is an end cap retainer that attaches the rotatable end cap to fuse body. 30 13. A cartridge fuse as claimed in claim 12 in which the end rap retainer that insulates the fuse element terminals from the rotatable end cap.

f Amendments to the claims have been filed as follows 7. A cartridge fuse as claimed in claim 6 in which the fuse is reusable in the event of failure of a fuse element by rotation of the end cap to bring another useable fuse element into contact with the rotatable end cap.

9. A cartridge fuse as claimed in any one of the preceding claims in which the fuse elements are of the same rating so that the fuse is reusable in the event of failure of a fuse element by rotation of the end cap to bring another useable 15 fuse element into contact with the rotatable end cap.

10. A cartridge fuse as claimed in any one of the preceding claims in which a hole in the rotatable end cap accommodates an axial spigot on an end cap retainer thereby securing the 20 end cap within freedom to rotate.

11. A cartridge fuse as claimed in any one or the preceding claims in which insulating material within the rotatable end cap electrically insulates the non-selected fuse element or 25 elements from the end cap.