GB2127627A

GB2127627A - Electrical component

Info

Publication number: GB2127627A
Application number: GB08322174A
Authority: GB
Inventors: Kenneth Pickles
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1982-08-18
Filing date: 1983-08-17
Publication date: 1984-04-11
Also published as: GB2127627B; GB8322174D0

Abstract

An electrical switch comprises a housing which has at least one terminal assembly to which an electrical lead (22) is to be attached. The terminal assembly embodies an electrically conductive strip (16), a resilient retainer member (25) which is arranged so that the electrical lead can be trapped between the strip (16) and the retainer member (25), together with a release element (27) which is slidably mounted in the housing for movement between a lead releasing position in which it engages the retainer member (25) to release the pressure exerted on the lead and a position in which said release element (27) is disengaged from the retainer member (25). The release element (27) is shaped so as to form a guideway for the lead (22). <IMAGE>

Description

SPECIFICATION Electrical component This invention relates to an electrical component and is more particularly concerned with an electrical component having a terminal assembly to which an electrical lead is to be attached.

It is an object of the present invention to provide an electrical component having a terminal assembly to which an electrical lead is easily secured and detached.

According to the present invention, there is provided an electrical component having a housing containing at least one terminal assembly to which an electrical lead is to be attached in use, said terminal assembly comprising an electrically conductive strip, a retainer member resiliently biassed towards a portion of one face of the strip so that an electrical lead can be trapped between said one face of the strip and the retainer member and held in contact with the strip by the retainer member, and an element extending into the housing and mounted thereon for sliding movement relative thereto into and out of a position in which it engages the retainer member to urge the latter against its resilient biassing in a direction to release the electrical lead, the element being disposed in the housing so as to be engageable with the retainer member adjacent to the location at which the lead is trapped, in use, between the strip and the retainer member, and the element being shaped so as at least partly to define a guideway for the electrical lead.

The element is preferably of hollow form for receiving the electrical lead and may be of the size to receive more than one electrical lead in the case where more than one such lead is required to be attached to the terminal assembly.

Alternatively, the element may be shaped so that a surface thereof defines one side of the guideway whose opposite side is defined by a surface of a passage in the housing which receives the element.

The element may be employed in conjunction with an arrangement where the retainer member is formed by an integral extension of the electrically conductive strip or may be employed in conjunction with an arrangement where the retainer member is a part which is produced separately from the electrically conductive strip.

In cases where two or more leads, which may be of different sizes, are to be attached to the terminal assembly, the retainer member may be provided with one or more slots or slits therein to define a plurality of retaining portions each intended to retain one of said two or more leads against said one face of the electrically strip.

In such an arrangement, the electrically conductive strip itself may be provided with a longitudinally projecting tongue which overlies part of the or each said slit or slot and which can be used to separate two adjacent leads. In such a case, an inner end of the element will be recessed suitably to accommodate the tongue and to allow relatively sliding movement between the element and the tongue to enable the former to engage the retainer member for movement of the latter relative to the electrically conductive strip. With such a construction the element may be of a size to receive one or more than one of the leads.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of one embodiment of an electrical component according to the present invention, in the form of an electrical switch, shown with part of the housing thereof removed, Figure 2 is a view of an inner end of a release element forming part of the switch of Figure 1, and Figure 3 is a view of an outer end of the element of Figure 2.

Referring now to the drawings the electrical switch is generally of the type disclosed in our copending British Patent Application No.8212598 filed on the 30th April 1 982 and entitled "Switch". Briefly, the switch comprises a two part housing of which one part only is shown and illustrated by arrow 1 0. The two parts of the housing are adapted to be clipped together by interengageable lugs and recesses in a manner known per se. The housing is formed of a suitable synthetic resin material and includes a synthetic resin slider 11 which is adapted for longitudinal movement in a slide-way 12 formed in the housing part 1 0. The slider 11 includes a head portion 1 3 which extends externally of the housing for manual depression by an operator of the switch.At the opposite end of the slider 11, a spring (not shown) is provided for biassing the slider 11 and head portion 13 outwardly. The slider 11 carries a pair of movable contacts in the form of rollers 14 and 1 5 which are arranged so as to bridge respective pairs of fixed contacts 16, 17, 18 and 19 disposed on opposite sides of the slide-way 12, upon depression of the head portion 1 3.Upon release of the head portion 13, the spring moves the slider 11 into a position in which the rollers 14 and 1 5 no longer bridge the respective fixed contacts 1 6, 1 7, 1 8 and 1 9. The fixed contact 1 7 and 19 are formed in the manner described in our co-pending British Patent Application No. 8212598 so as to define terminal portions to which respective pairs of electrical leads 20 and 21 are attached. In Figure 1, the leads 20 and 21 are shown only associated with fixed contact 1 9. The manner in which the leads 20 and 21 are actually engaged with the fixed contact 1 9 forms no part of the present invention and will be described in no further detail.

On the opposite side of the housing to the fixed contacts 1 7 and 19, the fixed contacts 1 6 and 1 8 are provided to each of which a single electrical lead 22 (only shown in relation to fixed contact 1 6) is attached. For this purpose, the fixed contacts 1 6 and 1 8 are respectively formed of an electrically conductive strip having a respective flat integral extension 23, 24 which lies against a respective internal surface of the housing. A retainer member 25, 26 and an associated release element 27, 28 defines with each extension 23, 24 a respective terminal assembly.

The retainer member 25 is in the form of a flat metal blade spring having one end lodged in a formation 29 in the housing and its opposite end engaging one face of the extension 23 when the release element 27 is in an outwardly biassed position (as shown in Figure 1 in relation to release element 28). The release element 27 is formed of a synthetic resin moulding and is engaged in the housing part 10 so as to be slidable in and out relative thereto. In Figure 1 , the release element 27 is shown in a position in which it has been slid fully inwardly so that an abutment shoulder 30 on an outer end thereof engages against a side wall of the housing part 10.In this position, an inner end surface of the release element 27 has engaged against the retainer member 25 so as to deform it inwardly against its inherent spring biassing This inward deformation of the retainer member 25 causes its end which is adjacent the extension 23 to be moved out of engagement with the latter to permit the bared end of lead 22 to be inserted between the retainer member 25 and the extension 23, or to be moved from this position.

Upon release of the release element 27, the latter is moved outwardly under the spring action of the retainer member 25 towards the position which has been adopted by release element 28 as illustrated in Figure 1. However, because of the presence of the bared end of the lead 22, the blade 25 will not actually engage against the surface of the extension 23, but will trap the bared end of the lead 22 in position. In order to release the lead 22, it is merely necessary to depress the release element 27 to the position shown in Figure 1, after which it is possible to remove the lead 22. Release of the element 27 once again, without the lead 22 being present, will cause the release element 27 to adopt the same position as that illustrated in Figure 1 for release element 28.In such position, the retainer member 25 is in a relatively unstressed condition and engages against the face of the extension 23.

As can be seen from Figures 2 and 3, the release element 27 is of generally square U-shaped configuration, with the U-shape opening downwardly as viewed in Figure 1, i.e. so that a portion of the extension 23 of the fixed contact 1 6 is exposed within the hollow of the release element 27. The lead 22 passes through the hollow release element 27 for engagement with the extension 23. The release element 27 has an inclined inner end such that in the unstressed state of the retainer member 25, the angle of inclination of the inner end of the release element 27 corresponds to that of the retainer member 25. At the base of the U-section of the release element 27, and the tops of the arms of the Ushape, the release element 27 is provided with respective abutment surface 31 and 32 for limiting outward movement of the release element 27.The release element 27 is engaged with the housing part 10 before the other part of the housing is assembled thereto. Alternatively, said element 27 can be clipped into position in the housing.

The release element 28 and the associated retainer member 26 are arranged in the same way as the above described arrangement of the release element 27 and associated retainer member 25.

The above described arrangement provides a particularly convenient and easy to operate construction since the release elements 27 and 28 act on the respective retainer members 25 and 26 at a point which is at a relatively remote location from the location at which the members 25 and 26 are elastically deformed in use. Thus, the force needed to operate the release elements 27 and 28 is relatively small. Additionally, it will be appreciated that the release elements 27 and 28 provide guideways for the electrical lead 22 and so a particularly compact construction is provided. Furthermore because the line of sliding action of the element 27,28 is normal to the side surface of the housing from which it extends, the element 27, 28 is easier to operate than an arrangement where said line of sliding action is inclined with respect to said normal.

In a modification (not shown), the release element, instead of being U-shaped section, is of shaped cross-section so as to accommodate the lead 22 in a guideway defined by one surface of the web of the I-shape, the adjacent inner surfaces of the flanges of the I-shape and an adjacent lateral surface of the housing of the switch. If required, such an I-shape can accommodate a further lead on the opposite side thereof to the first mentioned lead 22. If used in conjunction with a retainer member having a slot or slit and a contact having a tongue overlying the slot or slit (e.g. as described in British Patent Application No. 8212598) the release element will be recessed to accommodate the tongue.

Claims

1.An electrical component having a housing containing at least one terminal assembly to which an electrical lead is to be attached in use, said terminal assembly comprising an electrically conductive strip, a retainer member resiliently biassed towards a portion of one face of the strip so that an electrical lead can be trapped between said one face of the strip and the retainer member and held in contact with the strip by the retainer member, and an element extending into the housing and mounted thereon for sliding movement relative thereto into and out of a position in which it engages the retainer member to urge the latter against its resilient biassing in a direction to release the electrical lead, the element being disposed in the housing so as to be engageable with the retainer member adjacent to the location at which the lead is trapped, in use, between the strip and the retainer member, and the element being shaped so as to at least partly to define a guideway for the electrical lead.

2. An electrical component as claimed in Claim 1 wherein said element is of hollow form for receiving the electrical lead.

3. An electrical component as claimed in Claim 1 or Claim 2 wherein the element is arranged to receive more than one electrical lead.

4. An electrical component as claimed in Claim 2 wherein one surface of the element defines one side of the guideway whose opposite side is defined by a surface of a passage in the housing which receives the element.

5. An electrical component as claimed in any one of the preceding claims wherein the retainer member comprises a part which is separate from the electrically conductive strip.

6. An electrical component as claimed in Claim 3 wherein the retainer member is provided with one or more slots or slits to define a plurality of retaining portions which are respectively intended to retain one of the electrical leads.

7. An electrical component as claimed in Claim 6 wherein the electrically conductive strip is provided with a longitudinally projecting tongue which overlies part of the or each slit or slot and which can be used to separate adjacent leads, the adjacent end of said element being recessed to accommodate said tongue.

8. An electrical component substantially as hereinbefore described with reference to and as shown in the accompanying drawings.