GB2146184A

GB2146184A - A fuse-link carrier

Info

Publication number: GB2146184A
Application number: GB08422020A
Authority: GB
Inventors: Brian John Wood; Peter Rowland Norrie
Original assignee: Midland Electric Manufacturing Co Ltd
Current assignee: Midland Electric Manufacturing Co Ltd
Priority date: 1983-09-06
Filing date: 1984-08-31
Publication date: 1985-04-11
Also published as: GB8422020D0; GB8323821D0; AU574381B2; NZ209449A; MY101666A; GB2146184B; AU3257584A

Abstract

A fuse-link carrier 1 generally comprises an elongate body portion 2 with a parallel pair of legs 3, 4 projecting from one side. Each of the legs 3, 4 has a resiliently displacable arm 5, 6 which extends from that leg towards the other leg 4, 3. The legs 3, 4 are spaced apart to receive a fuse-link F of the cartridge type. The legs 3, 4 have notches 20. A fuse-link F is inserted between the legs 3, 4 and the resilient arms 5, 6 as displaced outwardly. When blades B are aligned with notches 20 the arms 5, 6 push the blades into the notches and the fuse-link is correctly aligned. <IMAGE>

Description

SPECIFICATION A fuse-link carrier This invention relates to a fuse-link carrier forming part of a fuse system for protecting an electrical circuit, the fuse system employing a fuse base which is connected in the electrical circuit, and which receives a fuselink mounted in the carrier.

A fuse-link carrier is used with a cooperating fuse base to enable a fuse-link to be connected in an electric circuit while being otherwise insulated and retained against accidental dislodgement. One type of fuse-link used with this type of carrier is the blade contact cartridge fuse-link which has a cylindrical body portion containing the fuse and a contact blade at each end of the body. In use each blade engages with a spring clip contact of a terminal block in the fuse base. It is desirable that a fuse of the cartridge type be readily removable to facilitate replacement, while still being held securely enough to avoid accidental dislodgement and to ensure that the contact blades can properly engage the terminal blocks.

This invention seeks to provide a fuse-link carrier of simple design, which is capable of carrying a blade contact cartridge type fuselink, and which retains the fuse-link in an acceptable manner, while allowing for easy insertion and removal of the fuse-link.

According to the invention a fuse-link carrier for carrying a fuse-link of the blade contact cartridge type, comprises: a body portion and two adjacent legs projecting from the body portion; each leg having a fuse retaining arm which extends transversely towards the other leg and which are resiliently deformable upon insertion of a fuse cartridge, so that the fuse cartridge can be held in the carrier in between the co-operating retaining arms, and means restricting movement of the fuse-link in the direction in which the legs project.

The invention provides a simple, yet effective design of fuse-link carrier which allows for ready access to a fuse-link.

It is preferred that the legs are arranged on the body so that part of the cartridge fuse is pressed into engagement with each leg by the resilient arms. Preferably the movement restricting means includes an abutment on each of the legs, which will be engaged by the fuse-link, if the fuse-link is moved in the direction of projection of the legs. Each leg may have its abutment formed by a recess or notch in the side of the leg, which notch receives part of the fuse, for example, the blade contact. Where each blade is held in a recess in each leg, the recesses are orientated to ensure that the blade contacts are aligned to engage the spring clips in the fuse base.

In a preferred embodiment of the invention the legs are dimensioned to be a close fit in the cooperating fuse base, so that the fuselink carrier can only be inserted into the fuse base in a manner which ensures that one of the contacts of the fuse-link is not exposed while the other is in electrical engagement with a terminal block in the fuse base.

A preferred embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, wherein: Figures 1 and 2 are perspective views of a fuse-link carrier without, and with, a fuse-link fitted, respectively.

Referring to the drawings, a fuse-link carrier 1 for carrying a fuse-link F generally comprises an elongate body portion 2 with a parallel pair of legs 3, 4 projecting from one side. Each of the legs 3, 4 has a resiliently displacable arm 5, 6 which extends from that leg towards the other leg 4, 3. The legs 3, 4 are spaced apart to receive a fuse-link F of the cartridge type which will be held by the arms 5, 6.

The body portion 2 of the carrier 1, has a skirt portion 7 which extends in the same direction as the legs 3, 4 to about one third the length of the legs. On the opposite side of the body portion 2 to the skirt 7 and legs 3, 4 there are finger grips 8, 9 which facilitate removal or insertion of the carrier in a fuse base. An annular rib 10 extends about the body portion 2, between the skirt and the finger grips 8, 9. Spaced apart on the skirt 7 are small vertical ribs 11 intended to form an interference fit with the inside of a fuse base.

Each leg 3, 4 has a generally L-shaped cross-section with one link extending across the carrier and the other link extending along the carrier and adjoining the skirt 7. Each leg 3, 4 has a sideways projecting lugs 12, 1 3 to make the width of the end of the leg just less than the internal width of the fuse base used with the carrier. The arms 5, 6 extend from the respective leg 3, 4 where the leg joins the skirt 17, and extend in line with the adjacent part of the skirt 7.

Each arm 5, 6 extends upwards from the skirt 7 and tapers in width and thickness. The arms are resiliently deformable, i.e. if outwardly displaced they tend to return inward to the position shown in the drawings. Each arm 5, 6 has a rounded tip portion 16, 1 7 which extends upwards in the direction of the legs 3, 4 and has an inner bevelled face 18, 19.

On the edge of each leg 3, 4 adjacent to the free end of each arm 5, 6 there is a rectangu lar notch 20, 21 which extends from just above the level of the skirt 7 to just below the tip of the adjacent arm. The size of the notch is slightly greater than the size of a blade B of a cartridge fuse. Within the skirt 7 ribs 24 project from the body portion 2 to just above the level of the skirt adjacent the notches 20, 21. Also, inside the skirt 7 and between the legs 3, 4 ribs 25 project from the body portion to just above the level of the skirt 7.

The level of the ribs 24, 25 projecting from the body 1 is the same as the lower level of the notches 20, 21.

The fuse carrier may be moulded in one piece and of a material which provides the necessary insulating qualities as well as rigidity and also resilient flexibility for the arms 5, 6. A suitable material is heat stabilised nylon.

In use, a fuse-link of the blade cartridge type is placed between the legs 3, 4 at angle to the major axis of the carrier with each blade resting against one of the legs, adjacent and above the notch of that leg. The body of the fuse cartridge and/or each blade engages the the tip of each of the arms and as the fuse F is pressed down the arms 5 and 6 are deflected outwards so that the body of the fuse can move further in between the legs 3, 4. The fuse remains at an angle to the body portion 2 until the blades of the fuse are below the upper level of the notches 20, 21.

The pressure of the resilient finger portions moves the blades into the notches 20, 21 and the fuse is thus aligned with the body portion 2 of the carrier. The blades are trapped within the notches against movement transverse to the legs by the pressure of the arms 5, 6 and against movement in the direction of the legs by the engagement of the blades with the ends of the notches. The blades of the fuselink are also supported by the ribs 24. The ribs 25 support the body of the fuse between the legs 3, 4.

The fuse may be removed by twisting it against the arms 5, 6 so that they are outwardly displaced and then pulling the blades of the fuse outwards between the tips of the arms 5, 6 and the legs 3, 4.

The embodiment of the invention provides a fuse carrier of apparently simple yet effective design. The blade contact fuse is readily accepted by the carrier and held against accidental dislodgement while being accessible and removable. The blades of the fuse are held within the notches in the legs in proper alignment for engagement with the terminal blocks in a fuse base.

The elongate legs of the fuse carrier may be received into co-operating shaped parts of a fuse base The standard form of fuse base has a rectangular base and four side walls which form a rectangular open-topped box. All of the fuse-link carrier except the base and hand grips are received by the box-like fuse base.

The legs in particular can extend to near the bottom of the inside of the box in order to locate the carrier accurately. The width of the legs can also be made just less than the internal width of the fuse base to assist in location of the carrier. Further modifications are possible e.g. rectangular channels can be formed in the fuse base. All these measures are to attempt to ensure that the carrier can only be inserted into the fuse-base linearly and the blades cannot contact the terminal blocks and be exposed at the same time.

Claims

1. A fuse-link carrier for carrying a fuselink of the blade contact cartridge type, comprises: a body portion and two adjacent legs projecting from the body portion; each leg having a fuse retaining arm which extends transversely towards the other leg and which is resiliently deformable upon insertion of a fuse cartridge, so that the fuse cartridge can be held in the carrier between the co-operating retaining arms, and means restricting movement of the fuse-link in the direction in which the legs project.

2. A fuse-link carrier as claimed in claim 1 wherein the movement restricting means includes an abutment on each of the legs. and the legs and arms are so arranged that parts of the fuse-link are pressed by the arms into engagement with the legs adjacent to abutments, whereby upon movement of the fuselink in the direction in which the legs project, the fuse-link will engage the abutments.

3. A fuse-link carrier as claimed in claim 2, wherein each abutment is formed by a notch for receiving a blade of the fuse-link.

4. A fuse-link carrier as claimed in claim 1 to 3 in combination with a fuse base having a rectangular open-topped box-like structure, wherein the legs are almost the internal depth of the fuse base and/or the width of at least part of the legs is almost the internal width of the fuse base, so that when the carrier is inserted in a fuse base one of the blade contacts of the fuse-link is not exposed while the other is in electrical engagement with the fuse base.

5. A fuse-link carrier as claimed in claim 4 wherein the legs have side extensions adjacent their ends so that the width of the legs including the side extensions is almost the internal width of the fuse base.

6. A fuse-link carrier substantially as herein described with reference to the accompanying drawings.