GB2054987A - Housing assembly for an electrical component - Google Patents

Abstract

A housing for a component such as a fuse (6) has an insulating base (2) provided at its edge with recesses which receive conductors (4). The fuse (6) is connected between the inner ends of the conductors (4). The conductors are positively located in the recesses by an insulating cap (3) which fits over and around and snaps onto the base (2). <IMAGE>

Description

SPECIFICATION Housing assembly for electrical component.

The invention relates to a housing assembly for an electrical component, the assembly comprising first and second parts made of electrically insulating material and complementing one another to form a housing; and at least two electrical conductors which are arranged to be connected, in use, to the electrical component within the housing and which extend out of the housing.

Housing assemblies of this kind may be used for totally enclosed electrical components, such as fusible conductors.

Hitherto the housing assembly conductors were first of all fastened onto the first housing part in their final positions. The followed the mounting of the electrical component, for example, the connection of a fusible conductor between the inner ends of the two conductors. After that the second part of the housing, which consists,for example, of a cover, was mounted on the first part and fastened to it by glueing or rivetting or some other suitable kind of connection. Examples of housings produced in this way, to the extent that they are intended for receiving fusible conductors, may be understood from West German O/S 1 813 430.

The object of the invention is to provide a construction of housing assembly which allows simpler assembly than hitherto.

In accordance with the invention this is achieved if the conductors are received in recesses at the edge of a base which forms the first part and are located in the recesses by inner portions of a cap which forms the second part and which can be fitted firmly over and around the base.

This solution depends upon the principle of not fastening the conductors to the base immovably while the electrical component is connected, but of arranging them at this time in the recesses provided in the base in the positions which they will adopt in the assembled housing. After connecting the electrical component, the cap is fitted to the base in a simple way by means of a plug-on connection, in which case appropriately formed inner portions of the cap secure the conductors in the recesses in the base. It is consequently only necessary, after laying the two conductors in the recesses at the edge of the base to hold them in this position by means of an auxiliary jig as long as is necessary for the fitting of the electrical component to the inner ends of the conductors.After that the position of the conductors becomes securely preserved by appropriate construction and mutual association of the base and cap without the application of further fastening means.

The invention enables elimination of the glueing or rivetting work respectively, which has been usual hitherto. Glued connections as the sole means of connection of elements which have an extremely small structural size as in the present case are anyhow problematic. First the mutual position with respect to one another of the elements which are to be glued is frequently not clearly defined, and secondly a uniform distribution of the adhesive demands in the case of elements of small structural size a high degree of carefulness both in the case of manual and also in the case of machine assembly.

Hence the invention unites the advantage of.a simplified manufacture with the further advantage that the fastening of the two housing parts together is more secure and their mutual position is more exact.

In order that the cap may secure the position of the conductors in the recesses at the edge of the base, the inner portions of the cap are preferably provided by beading which rests against and directs pressure inwardly against surfaces of the conductors facing outwardly from the recesses. In this case care has to be taken that the beading comes into contact only with the outer surfaces of the conductors but not with parts of the base, so that the pressure applied by the beading because of its dimensioning and material, which preferably exhibits a certain elasticity, acts as exclusively as possible upon the conductors.

The beading, or adjacent other, inner parts of the cap preferably snap resiliently behind a shoulder at the edge of the base when the cap is fitted to the base to secure the cap onto the base.

The inner beading of the cap may therefore act both in the radial direction for securing the position of the conductors and in the axial direction for fixing of the cap onto the base.

During assembly of the housing and during the connection of the electric component to the inner ends of the conductors the outer ends of the conductors may for the preservation of their positions in the recesses, in the base be located in openings arranged at an appropriate distance apart in a jig.

For securing the conductors against displacement longitudinally into and out of the housings, various solutions may be applied.

Thus, each conductor may be prevented from displacement longitudinally out of the housing by means of a bent over inner end of the conductor which engages over an upper surface of the base.

The bent-over end may at the same time provide the connection to the electrical component.

Displacement of the conductors longitudinally into the housing may be prevented by means of a lateral projection spaced from the inner end of the conductor and engaging a complementary shoulder on the base. In order, particularly also in the case of this construction, to ensure that between the cap and the base a certain minimum distance always exists, it may be advantageous if the base carries upwardly projecting dogs which engage the cap to act as distance pieces between the cap and the rest of the base.

In accordance with another solution, each conductor is prevented from displacement longitudinally into the housing by means of an inner end of the conductor which engages an under surface of the cap, thereby also providing a distance piece between the base and cap. The inner end of each conductor may then be slit in the longitudinal direction to provide two legs, one of which is bent over and engages over the upper surface of the base whilst the other engages the under surface of the cap.

Some examples of fusible links constructed in accordance with the invention are illustrated in the accompanying drawings, in which Figure 1 is a section through a first example in the assembled state ready for service; Figure 2 is a section corresponding to Figure 1 but showing only the housing base; Figure 3 is a plan of the housing base; Figure 4 is a side elevation of the housing base as seen perpendicularly to the section of Figure 2; Figure 5 is an underneath plan of the housing base; Figures 6 and 7 are side and front elevations respectively of a conductor of the first example; Figure 8 is a section of the housing cap of the first example; Figure 9 is a section similar to Figure 1 but of a second example and with the addition of a jig for use in assembly;; Figures 10, 11 and 12 correspond to Figures 2, 3 and 4 but show the second example; Figures 1 3 and 14 are side and front elevations respectively of a conductor of the second example; Figure 1 5 is a section similar to Figure 8 but of the housing cap of the second example; and, Figures 16 and 17 are side and front elevations respectively of an alternative form of conductor which may be used in the second example.

The housing assembly which may be seen in Figure 1 and is designated in general by 1 consists of a housing base 2 and a housing cap 3 which is slipped firmly onto the base 2 to form a housing, and conductors 4 secured in the position illustrated between the base 2 and the cap 3, and between the inner ends of which runs a fusible conductor 6 connected at each end to one of the conductors 4 by a bead 5 of solder.

For the reception of the conductors 4 the base 2 has at its edge recesses 7 lying diametrically opposite one another. A widening 8 of the recess 7 serves in each case for the reception of projections 9 from the conductors 4 and provides shoulders for securing them against displacement longitudinally into the housing. The securing of the conductors 4 against displacement in the other direction is effected by the engagement over an upper surface of the base 2 of bent-over inner ends 10 of the conductors 4.

The cap 3 which may be seen in particular from Figure 8 has a bead 11 running right round on the inside. As shown in Figure 1 this bead rests against the outer surfaces of the conductors 4, that is, under pressure because of appropriate dimensioning and the springy characteristics of the insulating material employed for the production of the base 2 and the cap 3, so that the conductors 4 respectively remain pressed into the recesses 7 in the base 2 under pressure.

The cap is fastened to the base 2 in a simple and secure way by a plug-on connection, the cap 3 being forced onto the base 2 until the bead 11 snaps in behind a shoulder on the underside of an edge 12 on the base 2. Dogs 13 formed on the surface of the base 2 act as distance-pieces between the rest of the base 2 and the cap 3.

The second example, illustrated in Figures 9 to 15, of a housing assembly 1 a, which likewise serves for the reception of a fusible conductor 6, is distinguished essentially from the first example by a different construction and longitudinal securing of the conductors 4 and by alterations resulting therefrom in the shape of the base 6. The shape and function of the cap 3 remains essentially the same. The inner ends 10 of the conductors 4 are in this example slit in the longitudinal direction as may be seen from Figures 13 and 14, so that there is a bent-over leg 1 Oa and a second leg 1 Ob which lies in the plane of the conductor 4. Upon assembly of the housing the leg 1 Ob takes over the function of the distance-piece between the cap 3 and the base 2, and also prevents displacement of the conductor into the housing.

As shown in Figure 9, the leg 1 Oa is connected to the corresponding end of the fusible conductor 6 by means of the bead 5 of solder.

At the time of the assembly of both examples, a simple auxiliary jig 14 may be used (cf. Figure 9).

The jig has two holes 1 5 arranged at a certain distance apart, into which the conductors 4, which are first of all only laid into the recesses 7 in the base 2, can be inserted as shown in Figure 9, whilst the fusible conductor 6 is connected to the inner ends 10, 1 Oa of the conductors 4. When this procedure has been concluded, the cap 3 is mounted on the base 2 and fastened to it in the way described, so that the conductors 4 are held securely in their predetermined position by the base 2 and the cap 3 and the jig 14 is no longer needed. In both examples, the base 2 exhibits a central recess 1 8 which produces the necessary clearance of the fusible conductor 6 from the other parts of the base.

Instead of the construction of the conductors 4 shown in Figures 9, 13 and 14, the variation which may be seen in Figures 1 6 and 1 7 may also be employed. In this case the inner end of the conductor 4 is shaped like a fork for receiving the fusible conductor. The shank below the forkshaped part, is shown in Figures 1 6 and 1 7 as having a rectangular cross-sectional form, but may alternatively be made circular in cross-section.

Shoulders 1 9 formed one on each side underneath the fork-shaped part, come into engagement with corresponding counterfaces of the base 2, so that the conductor 4 is secured against unintentional withdrawal from the base 2, whilst the tines of the fork like the corresponding parts of the other example secure the distance of the cap 3 from the base 2. This example is advantageous because it can be produced in a simple way and results in a gain in free contact distance, as compared with the other examples, so that higher currents may be interrupted and consequently the possibility results of employment in applications with higher nominal voltages.

Claims (12)

1. A housing assembly for an electrical component, the assembly comprising first and second parts made of electrically insulating material and complementing one another to form a housing; and at least two electrical conductors which are arranged to be connected, in use, to the electrical component within the housing and which extend out of the housing, characterised in that the conductors are received in recesses at the edge of a base which forms the first part and are located in the recesses by inner portions of a cap which forms the second part and which can be fitted firmly over and around the base.

2. An assembly according to claim 1, in which the inner portions of the cap are provided by beading which rests against and directs pressure inwardly against surfaces of the conductors facing outwardly from the recesses.

3. An assembly according to claim 1 or claim 2, which in inner portions of the cap are arranged to snap resiliently behind a shoulder at the edge of the base when the cap is fitted to the base to secure the cap onto the base.

4. An assembly according to any one of the preceding claims, in which each conductor is prevented from displacement longitudinally out of the housing by means of a bent over inner end of the conductor which engages over an upper surface of the base.

5. An assembly according to any one of the preceding claims, in which each conductor is prevented from displacement longitudinally into the housing by means of an inner end of the conductor which engages an under surface of the cap, thereby also providing a distance piece between the base and cap.

6. An assembly according to claims 4 and 5, in which the inner end of each conductor is slit in the longitudinal direction to provide two legs, one of which is bent over and engages over the upper surface of the base whilst the other engages the under surface of the cap.

7. An assembly according to any one of claims 1 to 4, in which each conductor is prevented from displacement longitudinally into the housing by means of a lateral projection spaced from the inner end of the conductor and engaging a complementary shoulder on the base.

8. An assembly according to any one of claims 1 to 4 and 7, in which the base carries upwardly projecting dogs which engage the cap to act as distance pieces between the cap and the rest of the base.

9. An assembly according to any one of the preceding claims, including an electrical component electrically connected between the inner ends of the conductors within the housing.

10. An assembly according to claim 9, substantially as described with reference to any one of the examples illustrated in the accompanying drawings.

11. A method of assembling an assembly according to claim 10 or claim 1 wherein the electrical component is connected to the inner ends of the conductors whilst the conductors are located in the recesses in the base by means of the projecting outer ends of the conductors being received in holes spaced an appropriate distance apart in a jig, whereafter the cap is fitted over the base.

12. A method according to claim 11, .substantially as described with reference to Figure 9 of the accompanying drawings.