GB2393046A

GB2393046A - Connectors and assemblies

Info

Publication number: GB2393046A
Application number: GB0317924A
Authority: GB
Inventors: John Pryce; Kath Wigley; Helen Pryce; Mark Bagnall
Original assignee: Cable Management Products Ltd
Current assignee: ABB Cable Management Products Ltd
Priority date: 2002-07-31
Filing date: 2003-07-31
Publication date: 2004-03-17
Also published as: GB0317924D0; GB0217693D0

Abstract

A connector having an outer housing with an internal cavity and a sub-assembly 35 fitted within the cavity, the sub-assembly 35 being slidable axially into the outer housing and being lockable within the housing by rotating the sub-assembly 35 relative to the housing, the sub-assembly 35 including a latch member 49 urged resiliently outwardly to engage a surface formation 32 on the inside of the housing such as to prevent rotation of the sub-assembly 35 until the latch 49 is released. The invention also relates to a cap for closing the connector 1, a flexible strap for attaching the cap to the connector and a collar attached to the outer housing so as to allow connection of the connector to another similar connector. The collar operating to resist separation of the two connectors until a pre-determined axial force is exceeded.

Description

CONNECTORS AND ASSEMBLIES

This invention relates to connectors and assemblies 5 An electrical connector assembly commonly comprises two connectors mounted at the end of cables that can be mated with one another so as to connect the cables electrically. Each connector may have an outer housing, such as of generally tubular form, and an inner sub-assembly. The inner sub-assembly carries electrical contacts and is removable from the outer housing to enable I0 connection to a cable. The outer housing provides protection and may have provision for locking the two connectors with one another. One form of such a connector is sold by Elkay Electrical Manufacturing Co Lid of Newtown, Powys, UK under the trade mark Aqua-safe.

15 One problem with such connector assemblies is in securely retaining the inner sub-assembly within the outer housing whilst enabling it to be removed for wiring purposes. Another problem may arise where the assembled connector assembly is subjected to very high forces exceeding its design limits, as it may fail in such a way as to expose live components within the connector. A further 20 problem is in attaching a cap to a connector, so as to enable the connector to be protected when not mated with its cooperating connector.

According to one aspect of the present invention there is provided a connector having an outer housing with an internal cavity and a subassembly 25 fitted within the cavity, the sub-assembly being slidable axially into the outer housing and being lockable within the housing by rotating the sub-assembly relative to the housing, the sub-assembly including a latch member urged resiliently outwardly to engage a surface formation on the inside of the housing such as to prevent rotation of the sub-assembly until the latch is released.

This arrangement retains the inner sub-assembly securely, while enabling

it to be removed if necessary, by operation of the latch.

The latch member is preferably arranged for engagement by a tool that is operable both to release the latch member from engagement with the surface 5 formation and to rotate the sub-assembly out of locking engagement with the housing. This makes removal of the sub-assembly simple.

According to a second aspect of the present invention there is provided a connector assembly having two connectors one of which has a part insertable 10 within a part on the other connector, the two connectors being retained with one another by resilient engagement of a first member on one part with a cooperating member on the other part, the first and cooperating members being shaped such that, when an axial force exceeding a certain limit is applied tending to separate the two connectors, the first member is deflected relative to the cooperating 15 member to permit separation of the two connectors.

This arrangement increases the safety of the assembly against excessive force applied to separate the connectors.

20 The first member is preferably provided on an outer part within a locking sleeve that is manually displaceable to allow the first member to move outwardly and permit separation of the two connectors.

According to a third aspect of the present invention there is provided a 25 flexible strap for retaining a member with a connector, the strap being adapted for threading through a retaining aperture and having a barbed portion that is compressible laterally such that the barbed portion can be compressed to pass through the retaining aperture in one direction and expands to resist withdrawal through the aperture in the opposite direction.

This provides a simple way of attaching the cap to the connector.

The barbed portion may be rendered compressible by means of an eye in the strap.

5 According to a fourth aspect of the present invention there is provided a connector for an assembly according to the second aspect of the invention.

According to a fifth aspect of the present invention there is provided a connector including a cap for closing the connector and a strap according to the 10 third aspect of the invention, the strap being attached at one end with the connector and at the other end with the cap.

An electrical connector assembly illustrating all aspects of the present invention will now be described, by way of example, with reference to the 15 accompanying drawings, in which: Figure I is a side elevation view of the assembly with both connectors mated together; 20 Figure 2 is a perspective view of the left-hand connector from its rear end; Figure 3 is a perspective view of the left-hand connector from its forward end showing the outer housing without the inner 25 part; Figure 4 is a perspective view of the left-hand connector from its forward end showing the outer housing with the inner part; 30 Figure 5 is an end view showing the inner part of the left-hand connector;

l Figure 6 is a sectional view through an inner part of the left-hand connector: 5 Figure 7 is a sectional side elevation view of parts of the ends of the two connectors, with the connectors separated; Figure 8 is a sectional side elevation view of the parts shown in Figure 7, with the connectors mated with one another; Figure 9 is a sectional side elevation view showing a modification of assembly; Figure 10 is a plan view of a strap used with the assembly; and Figure 11 is a perspective view of a cap used to close one of the connectors; With reference first to Figure 1, the assembly comprises a left-hand 20 connector l attached to an electrical cable 2 and a right-hand connector 3 attached to a second cable 4. The connectors I and 3 are joined with one another and retained together by means of a locking sleeve 30 on the right-

hand connector. The assembly provides a waterproof electrical interconnection of the two cables 2 and 4.

With reference now also to Figures 2 to 6, the left-hand connector 1 takes the form of a plug having an outer tubular housing 10 of generally circular section. At its rear, left-hand end the housing 10 has a screwthreaded portion 11 on which is threaded a clamping nut 12, which bears on an internal gland of 30 conventional kind (not shown) making a fluidtight seal with the outside of the cable 2. The nut 12 and housing 10 have respective hexagonal portions 13 and 14

by which spanners can be used to tighten or loosen the nut on the housing.

The central portion 15 of the housing is of cylindrical shape with a longitudinally-extending alignment rib 16. The forward end 17 of the central 5 portion 15 is enlarged and has a radially projecting ring 18, the purpose of which will be explained later.

The forward, right-hand portion 19 of the housing 10 has three longitudinally-extending locking bars 21 to 23 spaced a short distance rearwardly 10 of the forward end of the connector. The locking bars 21 to 23 are not equally spaced around the housing but are instead located at 0 , 150 and 210 relative to the alignment rib 16. Each bar 21 to 23 has an inclined leading edge 24 and a plane outwardly-facing edge 25 that is interrupted by a locking detent 26 of square profile. Forwardly of the bars 21 to 23, the housing has an external 15 annular channel 27 which retains an annular sealing ring 28. Forwardly of the channel 27 the housing has a tapered, frusto-conical end face 29.

Internally, the housing 10 has a through bore 30 and an annular step 31 at the rear end of the right-hand portion l 9. Two ribs 32 and 33 extend 20 longitudinally from the forward end of the housing to within about 9mm of the step 31. The ribs 32 and 33 are arranged diametrically opposite one another within the forward end of the housing, one rib 32 being wider than the other 33, so as to provide a keying function as described below.

25 The plug connector 1 is completed by an inner subassembly 35 located within the forward end of the connector. The subassembly 35 comprises an integral moulded plastics body 36 having a rear portion 37 of substantially cylindrical shape provided with two slots 42 and 43 positioned diametrically on its outer surface. The width of the slots 42 and 43 is selected to match the width 30 of the ribs 32 and 33 respectively, that is, one slot 42 is wider than the other 43.

Three tubular sleeves 45 to 47 project forwardly from the rear portion 37 side

by-side and enclose respective electrical contacts 38 to 40. A blocking plate 48 extends above the sleeves 45 to 47. The blocking plate 48 carries a latch 49 attached at its right-hand end (when viewed from the forward end) with the plate by an integral, resilient hinge 50. The latch 49 has an outwardly-projecting tooth 5 51 at its upper left-hand end and has a rectangular slot 52 centrally to receive a screwdriver or similar tool. The blocking plate 48 restricts the size of the opening in front of the latch 49 so that it cannot be contacted by a user's finger, but only by a screwdriver or similar tool. The contacts 38 to 40 are provided by three metal socket components, each having a conventional socket extending 10 along a respective sleeve 45 to 47 and adapted to make contact with a contact pin on the other connector when this is inserted within the sleeve. The rear end of each socket component is open to receive an inserted wire and has a screw in a transverse tapped hole that is screwed down to retain the wire in the usual way.

15 To load the subassembly 35 into the housing 10, the slots 42 and 43 on the body 36 are aligned with the ribs 32 and 33 respectively. The subassembly 35 is pushed rearwardly into the housing 10, guided by the ribs 32 and 33, until the rear of the body 36 abuts the internal step 31. The subassembly 35 is then rotated clockwise relative to the housing by about 45 , the extent of rotation being 20 limited by engagement of surface formations on the forward surface of the rear portion 37 of the body 36 with the ribs 32 and 33. As the subassembly 35 is rotated, the surface of the latch 49 rides over the rib 32 until its tooth 51 snaps against one side of the rib and prevents anticlockwise rotation of the subassembly relative to the housing 10. This retains the subassembly 35 securely in the 25 housing 10 where it is trapped between the step 31 and the rear end of the ribs 32 and 33. To remove the subassembly 35, the user inserts a screwdriver or similar tool into the slot 52 in the latch 49 from the forward end of the connector I and twists this anticlockwise. This initially rotates the latch 49 about its hinge 50 relative to the rest of the body 36, thereby disengaging the tooth 51 from the rib 30 32. Further rotation causes the entire subassembly 35 to rotate relative to the housing 10, the subassembly being rotated by about 45 until the slots 42 and 43

on the body 36 align with the ribs 32 and 33. In this position the subassembly 35 can be pulled out of the housing 10, such as for connection or disconnection of the cable 2.

5 With reference now also to Figures 7 and 8, the other, socket connector 3 is substantially identical at its rear end 60 and has a similar subassembly (not shown) within the forward end 61 of its housing 62. This has three male contact pins arranged for insertion in the sockets contacts in the plug connector 1. The subassembly is retained in the housing 62 by a similar latch arrangement to that 10 described for the plug connector. The inside of the forward end of the housing 62 has three shallow channels 63 positioned around the housing to receive the locking bars 21 to 23 on the mating connector 1. An aperture 64 extends through the wall of the housing 62 approximately midway along each channel 63. The socket connector 3 includes the locking collar 30 mounted on the forward end of 15 the housing 62. The locking collar 30 is a moulded plastics component of cylindrical shape having three integral, internal locking catches 65 located to align with the locking bars 21 to 23 on the other connector l. Each catch 65 is formed within a respective channel 66 extending along the inside of the collar 30 and comprises a resilient arm 67 attached towards the rear end of the collar and 20 extending forwardly to its free end where it is terminated by a locking finger 68.

Each finger 68 projects radially inwardly through a respective one of the apertures 64 and protrudes into the bore 69 through the housing 62. The forward face 70 of the finger 68 extends radially, that is, it is inclined at right angles to the axis but the rear face 71 is angled slightly forwardly away from the radius 25 typically at an angle a around 10 to the radius.

The collar 30 is fitted on the housing 62 from its forward end by sliding rearwardly until the fingers 68 snap into the apertures 64, this engagement being sufficient to retain the collar in place. The collar 30 can be pushed back a short 30 distance against the resilience of the arms 67 until its rear end abuts a flange 72 (Figure l) on the housing 62. Pushing back the collar 30, in this way, displaces

the fingers 68 a short distance radially outwardly. When the collar 30 is released, the resilience of the arms 67 moves it forwardly to its rest position with the fingers 68 projecting to their full extent into the housing 62.

5 The two connectors 1 and 3 are joined together by aligning their respective alignment ribs 16 and 76 and offering the plug connector up to the socket connector. The forward, tapered end 29 of the plug connector I is a relatively loose fit in the forward end 61 of the socket connector 3 to provide an initial guide for further insertion. As the two connectors 1 and 3 are pushed 10 further together, the locking bars 21 to 23 on the plug connector 1 align and move along the three channels 63 on the inside of the socket connector 3. Also, the electrical contact pins on the socket connector 3 enter the socket contacts 38 to 40 on the plug connector 1 to start making electrical interconnection between the connectors. Further insertion of the plug connector 1 causes the inclined 15 forward face 24 on the locking bars 21 to 23 to engage the forward face 70 of respective ones of the locking fingers 68, thereby urging the locking arms 67 outwardly against their resilience. The inner edge of the fingers 68 slides over the housing 10 of the plug connector 1 until they are level with the locking detent 26 in the respective locking bar 21 to 23, when they snap inwardly into the 20 detent. At this position, as shown in Figure 8, the forward end 29 of the plug connector housing 10 abuts a step 77 on the inside of the socket connector housing 62 and the sealing ring 28 is in sealing contact with the inside of the housing. The electrical contacts on the two connectors 1 and 3 are also fully engaged. The locking collar 30 retains the two connectors together. When the 25 connectors are to be released, the collar 30 is pushed rearwardly of the socket connector 30 to move the locking fingers 68 outwardly, out of engagement with the locking detent 26.

The incline 71 on the rear face of the locking fingers 68 allows the fingers 30 to be moved outwardly by engagement with the forward edge of the detent 26 if sufficient force is applied. The angle of the incline is selected such that the

locking arms 67 will only release from the detents 26 if the separating force is higher than that met in normal use but less than that which would cause damage to the assembly, typically the release force is around 15kg force. In this way, there is a reduced risk that excessive force would lead to damage exposing live 5 wires or contacts.

Instead of providing an incline on the fingers 68, the incline could be provided on the forward face 56' of the locking detent 26', as shown in Figure 9.

Alternatively, both the detent and the finger could have inclined surfaces.

Both connectors have retaining rings 18 and 78 by which a cap can be retained with the connector for closing its forward end when not mated with the other connector. The cap 90 used to close the socket connector 3 is shown in Figure 11 and this is retained with the connector by means of a strap 80 of the 15 kind shown in Figure 10. The strap 80 is of a flexible plastics material having a main section 81 and two opposite end sections 82 and 83 of reduced width. The width of these sections 82 and 83 is substantially identical to the diameter of the hole through the retaining rings 18 and 78. The ends 84 and 85 of the strap 80 are tapered and barbed with two outwardly-projecting teeth 86 on either side of 20 the strap. An elongate eye 87 extends along the barbed region rearwardly beyond the end of the barb 84 and 85 and being about twice its length. The width of the barb 84 and 85 across the teeth 86 exceeds the diameter of the hole in the retaining rings 18 and 78 but the eye 87 enables the strap to be compressed as the barb is threaded through the ring. The barb expands when its teeth clear the ring 25 so as to prevent it being pulled out.

The cap 90 has a similar retaining ring 91 through which the other end of the strap 80 can be threaded so that the cap is retained with the connector. The cap 90 shown in Figure 11 is closed at its rear end 92 and is open at its forward end 93 30 such that the contacts within the socket connector 3 can be received within the cap.

The external shape of the cap 90 is the same as the forward end of the plug

connector 1, having locking bars 94 and a sealing ring 9S at its forward end 93. The cap 90, therefore, is retained in the socket connector 3 in the same way as is the plug connector 1 and can be removed by pushing the locking collar 30 rearwardly.

The cap for the plug connector (not shown) resembles the forward end of the socket 5 connector 3 and has a similar locking collar.

The present invention in its various aspects has a number of advantages.

The latch arrangement for the inner part provides a secure retention of that part whilst still enabling it to be removed from the housing easily. The incline on the 10 locking collar and, or alternatively, the detent, increases the safety of the assembly against excessive force applied to separate the connectors. The retaining strap enables an article to be secured with a connector easily by the user.

Claims

1. A connector having an outer housing with an internal cavity and a subassembly fitted within the cavity, the sub-assembly being slidable 5 axially into the outer housing and being lockable within the housing by rotating the sub-assembly relative to the housing, the sub-assembly including a latch member urged resiliently outwardly to engage a surface formation on the inside of the housing such as to prevent rotation of the sub-assembly until the latch is released.

2. A connector according to claim 1, in which the latch member is arranged for engagement by a tool that is operable both to release the latch member from engagement with the surface formation and to rotate the sub-assembly out of locking engagement with the housing.

3. A connector according to any preceding claim in which the sub-

assembly carries tubular sleeves that enclose electric contacts.

4. A connector according to claim 2 or claim 3, in which a blocking 20 plate extends from the sub-assembly above the sleeves to restrict the size of the opening in front of the latch so that it cannot be contacted by a user's finger but only by the tool.

5. A connector assembly having two connectors one of which has a 25 part insertable within a part of the other connector, the two connectors being retained with one another by resilient engagement of a first member on one part with a co-operating member on the other part, the first and cooperating members being shaped such that, when an axial force exceeding a certain limit is applied tending to separate the two 30 connectors, the first member is deflected relative to the co-operating member to permit separation of the two connectors.

6. A connector assembly according to claim 5, in which the first member is provided on an outer part within a locking sleeve that is manually displaceable to allow the first member to move outwardly and 5 permit separation of the two connectors.

7. A Connector assembly according to claim 5 or claim 6, in which the connectors include complementary ribs and slots so as to provide a keying function.

8. A connector for an assembly according to any of claims 5 to 7.

9. A flexible strap for retaining a member with a connector, the strap being adapted for threading through a retaining aperture and having a 15 barbed portion that is compressible laterally such that the barbed portion can be compressed to pass through the retaining aperture in one direction and expands to resist withdrawal through the aperture in the opposite direction. 20

10. A flexible strap according to claim 9, in which the barbed portion is rendered compressible by means of an eye in the strap.

11. A connector that includes a cap for closing the connector and a strap according to claim 9, the strap being attached at one end with the 25 connector and at the other end with the cap.

12. A connector substantially as described herein with reference to and as illustrated in the accompanying drawings.

30

13. A connector assembly substantially as described herein with reference to and as illustrated in Figure 1 of the drawings.

14. A flexible strap substantially as described herein with reference to and as illustrated in Figure 10 of the accompanying drawings.

5

15. A connector that includes a cap as described herein with reference to and as illustrated in Figure 11 of the drawings.