GB2268639A - Electrical cable grip - Google Patents

Abstract

An electrical component such as a plug or socket has a housing formed by opposed shells 1A and 1B within which is a track for a cable 3. The cable is retained in the housing by clamping between a pair of opposed grippers 25 which engage one in each of an array of flange seatings 12 to 16 on the respective housing parts. The seatings vary in depth radially of the cable track and the grippers can be engaged with selected seatings on the respective arrays as appropriate for gripping and retaining different diameter of cable between opposed pairs of pointed members 26. <IMAGE>

Description

TITLE "An electrical component" TECHNICAL FIELD & BACKGROUND ART The present invention relates to an electrical component of the kind having a housing with a longitudinally extending track along which is to be received an electrical cable. It is well known to provide such components, typically an electrical plug or socket, with retaining means within the housing by which the cable is gripped or clamped and restrained from being withdrawn from the housing. This is to alleviate strain which may otherwise be applied on electrical terminals to which the cable may be attached within the component.

A conventional cable retaining means is in the form of a seating and crossbar between which the cable is clamped by screws or bolts engaging between the bar and the seating. While such a structure provides firm retention and is adjustable to accommodate different diameter cables, it is somewhat inconvenient as it necessitates a separate unclamping operation to remove or adjust the cable when the housing is opened. Furthermore, in some such known structures the clamping bar tends to deform to accommodate a cable of a particular diameter on which it is first used and if it is subsequently used on a smaller diameter cable the clamp may be ineffective. In a further known form of cable retaining means a flexible plastics clip is provided having opposed legs between which the cable is received and gripped.Although the legs can resiliently engage cables of different diameters it is generally considered that the range of diameter of cable which the legs can clamp efficiently is restricted in comparison with the clamping bar and seating arrangement. It is an object of the present invention to provide an electrical component, such as a plug or socket, having a cable track with a simple, efficient and relatively inexpensive cable retaining means which is adjustable to accommodate different diameter of cable and alleviates the disadvantages of the .prior proposals.

STATEMENT OF INVENTION AND ADVANTAGES According to the present invention there is provided an electrical component having a housing with a longitudinally extending track along which is to be received an electrical cable and cable retaining means within the housing comprising an array of at least two seatings spaced longitudinally of the track and a retaining part engageable with a said seating for gripping a cable disposed in the track, and wherein said retaining part when engaged with one seating as compared with another in the array is positioned at different lateral spacings relative to the cable track whereby the retaining means is adjustable by engaging the retaining part with a selected seating in the array as appropriate for gripping a cable of a predetermined diameter selected from cables of different diameter which may be accommodated in the track.

By the present invention it is intended that when a cable (wire or similar elongated component) of a particular diameter (or appropriate lateral dimension if the cable is other than of circular section) is to be fitted to the electrical component, the retaining part is engaged with a predetermined one of two or more seatings in the longitudinally spaced array so that the seating which is selected locates the retaining part at a predetermined lateral spacing from the cable track whereby when the cable is disposed inthe track in the housing, the retaining part will grip or clamp the cable with appropriate pressure to restrain the cable from being withdrawn from the housing.

Usually electrical cables are provided with a plastics cover or outer sleeve and the retaining part may be provided with teeth or serrations which bite or form indentations in the cable to provide a firm gripping or clamping effect. The housing will usually be formed of two or more housing parts which are open or openable, possibly being hinged together or separable, to facilitate location of the cable in the track (and usually attachment of the cable to electrical terminals in the component) and subsequently closed or assembled and secured around the cable. In such an arrangement it is preferred that the closure or assembly of the housing parts over the cable automatically results in the retaining part in its selected seating clamping the cable with appropriate retaining pressure.Usually the housing parts will be secured together by screws or bolts although other forms of securing means.may be provided such as spring clips or snap engaging fittings. It is also possible for the housing parts to be welded or adhesively secured together to provide a permanent fitting between the component and cable. Conveniently the retaining part firmly engages with its selected seating as a friction fit so that if the housing parts are separable or openable for removal or adjustment of the cable in the housing, the retaining part will normally remain in its seating and the cable is immediately released from its track.

The seatings will usually be formed by a longitudinally spaced array of recesses or projections within or on which the retaining part is engaged.

Preferably the seatings are formed by a longitudinally spaced array of flanges which extend laterally on the housing and the retaining part has a laterally directed peripheral recess within which a selected flange in the array is received in slot engagement.

Where the housing is formed from two or more housing parts which are assembled or closed together to form the housing with its cable track, the housing parts may be identical for convenient and inexpensive manufacture, particularly when each housing part is a plastics moulding.

With two or more housing parts, the array of seatings may be provided in one of those housing parts for the retaining part to be selectively adjustable on that housing part while the other housing part or parts when assembled or closed to form the housing clamp the cable on the retaining part in or on its selected seating.

Alternatively each of two or more of the housing parts may be provided with an array of seatings, each of which has a retaining part engageable with a selected seating in the respective array so that when the housing is assembled from the housing parts the cable is gripped by all of the retaining parts which are presented one from each of the seating arrays in the respective housing parts. In this latter arrangement it is preferred that the housing parts are arranged so that when assembled or closed to form the housing the respective seatings are substantially co-planar in the lateral direction of the cable track with the seatings in a common lateral plane being intended to be engaged by respective retaining parts to position those parts for clamping between them a particular diameter of cable. Conveniently the housing is formed of two substantially identical opposed housing parts. The retaining part or parts will usually be formed as plastics mouldings.

DRAWINGS One embodiment of an electrical component constructed in accordance with the present invention and having a housing formed by a pair of identical and opposed housing parts will now be described, by way of example only, with reference to the accompanying illustrative drawings, in which: Figure 1 is a perspective view of one of the housing parts of the component prior to fitting a retaining part thereto; Figure 2 is a perspective view of a retaining part for use with the housing part shown in Figure 1; Figure 3 is a side elevation of the housing part shown in Figure 1 with the retaining part fitted thereto; Figure 4 shows the pair of housing parts each as shown in Figure 1 assembled together to form a housing of the component and is a section indicated along the line B - B of Figure 3;; Figure 5 is a section through the housing along the plane indicated at C - C in Figure 4 and diagrammatically illustrates the manner in which retaining parts shown in Figure 2 are engageable with the housing parts, and Figure 6 is a section of the component taken on the line A - A of Figure 5 and diagrammatically illustrates selective positioning of the retaining parts to accommodate and clamp different diameters of cable which may be fitted to the component.

DETAILED DESCRIPTION OF DRAWINGS The electrical component illustrated is in the form of a plug or socket having a housing 1 which provides a substantially straight longitudinally extending track that is substantially concentric with an axis 2 of the housing and along which an electric cable or wire 3 is to be accommodated. The housing 1 is assembled from a pair of housing parts formed as identical plastics moulded shells 1A and 1B. In practice the housing 1 or its parts 1A and 1B will be formed as an extension or part of or attached to a terminal head indicated at 4 of the plug or socket and which head carries electrical terminals to which the cable 3 is connected. The structure of the terminal head 4 is irrelevant to the present invention and may be regarded as conventional.

The housing shells 1A and 1B are assembled together in directly opposing relationship to provide the housing 1 with a longitudinally extending generally tubular cavity 5 through which the cable may extend between circular openings 6 and 7 formed by opposing semi-circular recesses in end walls 8 and 9 of the shells. The shells are secured together in their opposing relationship by bolts 10 engaging through co-operating holes 11 in the shells.

Each shell 1A and 1B is provided with an array of parallel seatings within the cavity 5 which are spaced longitudinally of the cable track or axis 2; in the present example five seatings are provided as shown at 12 to 16. Each of the seatings is formed by a flange on the respective shell which extends laterally of the cable track (or in a radial plane relative to the axis 2).

Furthermore, the flange for each seating forms a centrally disposed generally rectangular opening the width of which is the same for all of the flanges and the depth of which varies from one flange to another (this will be seen particularly from Figure 1 where the central opening for the seating flange 12 is relatively shallow and the central openings become progressively deeper through the respective seating flanges 13 to 16. The central openings provide the seating flanges with opposed substantially parallel laterally extending guide walls 20 and a laterally extending bottom wall 21. The generally rectangular openings in the seating flanges consequently provide for the bottom walls 21 to upstand laterally on the respective shells 1A and 1B at different heights which height reduces from one seating flange to another progressively through the flanges 12 to 16 as shown in Figure 5.

For the purpose of retaining a cable 3.received within the housing 1, a pair of identical plastics moulded cable grippers 25 are provided one for each array of seatings in the two housing shells 1A and 1B. The gripper 25 has a pair of axially spaced substantially straight and apically formed teeth 26 which extend laterally from a base 27 having substantially parallel and laterally opposed edges 28. Located within the edges 28 and extending around the periphery of the base part 27 is a recess 29.The gripper 25 is sized and profiled to be fitted into a selected one of any of the rectangular central openings in the seating flanges 12 to 16 so that the opposed side wall parts 20 of the selected flange are received as a close sliding fit within the recess 29 in the gripper as the gripper is pushed into the central opening of the seating flange until it abuts the bottom wall 21 of that flange (where the bottom wall 21 may be received within the peripheral recess 29. When the gripper 25 is firmly engaged as a friction fit with a particular seating, its parallel side edges 28 with the recess 29 may abut the wall parts 20 of the flange with which it engages (or the side edges 28 may abut other adjacent wall surfaces of the shell) to restrain the gripper from rocking in its seat.Because of the different heights of the bottom walls 21 in the flange seatings it will be realised that, depending to which particular seating in an array the gripper 25 is fitted, the gripper teeth 26 can be spaced laterally or radially of the axis 2 by different distances from the cable track or axis 2. This is particularly evident from Figure 5 in which, solely for convenience of description, a gripper 25 is shown fitted to each of the seatings 12 to 16 for the two housing shells with those shells assembled in directly opposing relationship to form the housing 1. In this latter relationship it will be seen that the pair of grippers on the two corresponding seatings of the two shells laterally or diametrically oppose each other in a common lateral plane.In practice a single pair of grippers 25 only will be provided, one for each of the shells 1A and 1B and these grippers will be fitted to selected seatings 12 to 16 which seatings will correspond on the two shells. The seatings that are selected will be determined by the particular diameter of cable 3 which the housing 1 is to accommodate so that when the housing shells are assembled and secured together with the grippers 25 fitted, the teeth 26 of the grippers will engage and bite diametrically opposed sides of the cable to clamp the cable automatically as the shells are bolted together. Again from Figure 5 it will be seen that a pair of grippers on the end seatings 12 are intended to clamp a relatively small diameter cable (as indicated at 3A in Figure 6) whereas a pair of grippers 25 on the opposing end seatings 16 are intended to clamp and retain the largest diameter cable (as indicated at 3B in Figure 6) which is to be accommodated within the housing and the intermediate seatings 13 to 15 permit pairs of grippers to be located as appropriate for gripping and retaining cable sizes between the smallest and largest diameters. In a typical plug or socket the pair of grippers 25 may be selectively positioned on the seating flanges in the two arrays for clamping cables having a diameter in the range of 6 to 15 millimetres. The grippers 25 are conveniently provided with opposed side flanges 26A adjacent to the teeth 26 to facilitate holding during their placement in or removal from the seatings 12 to 16. The flanges 26A are also convenient for location of a screwdriver head to lever the gripper from a seating. The seatings 12 to 16 are conveniently marked or otherwise identified for a location of a gripper to clamp a cable of a particular diameter.

Claims (15)

1. An electrical component having a housing with a longitudinally extending track along which is to be received an electrical cable and cable retaining means within the housing comprising an array of at least two seatings spaced longitudinally of the track and a retaining part engageable with a said seating for gripping a cable disposed in the track, and wherein said retaining part when engaged with one seating as compared with another in the array is positioned at different lateral spacings relative to the cable track whereby the retaining means is adjustable by engaging the retaining part with a selected seating in the array as appropriate for gripping a cable of a predetermined diameter selected from cables of different diameter which may be accommodated in the track.

2. A component as claimed in claim 1 in which the seatings comprise a longitudinally spaced array of laterally extending projections or recesses in the housing on or within which the retaining part is engaged.

3. A component as claimed in claim 2 in which the seatings comprise laterally extending flanges and the retaining part has a laterally directed recess at its periphery within which a selected flange is received in slot engagement.

4. A component as claimed in any one of the preceding claims in which the housing comprises housing parts which when open facilitate adjustment of the retaining means and location of a cable along the track, said housing parts being assembled or closed together to form the housing and wherein during said assembly or closure of the housing parts a cable accommodated in the track is clamped automatically by the retaining part.

5. A component as claimed in claim 4 in which the array of seatings is provided on a single housing part for the retaining part to be selectively adjustable on that housing part.

6. A component as claimed in claim 4 in which each of at least two housing parts is provided with a said array of seatings and at least two retaining parts are provided for engagement one with each of a selected seating in the respective arrays for the cable to be clamped between the two or more retaining parts provided when the housing parts are closed or assembled together to form the housing.

7. A component as claimed in claim 6 in whidh the housing parts are substantially identical to each other.

8. A component as claimed in claim 7 and comprising two housing parts which are disposed in directly opposing relationship and secured together to form the housing.

9. A component as claimed in any one of claims 6 to 8 in which respective seatings in the arrays on the housing parts are located in substantially common respective lateral planes whereby retaining parts on respective seatings in a common lateral plane are intended to clamp between them cable of a predetermined diameter.

10. A component as claimed in any one of claims 6 to 9 in which the retaining parts are identical to each other.

11. A component as claimed in any one of the preceding claims in which the retaining part is provided with teeth which is intended to engage and bite into a cable retained within the housing.

12. A component as claimed in any one of the preceding claims in which the retaining part is restrained from rocking in its seating by abutment with a wall on the housing.

13. A component as claimed in any one of the preceding claims in which the housing, seatings and retaining part comprise plastics mouldings.

14. A component as claimed in any one of the preceding claims and in the form of a plug or socket.

15. An electrical component substantially as herein described with reference to the accompanying illustrative drawings.