CA2103803A1

CA2103803A1 - Sealed electrical connector

Info

Publication number: CA2103803A1
Application number: CA002103803A
Authority: CA
Inventors: Joris Isabella Franckx
Original assignee: Individual
Current assignee: Commscope Connectivity Belgium BVBA
Priority date: 1991-02-25
Filing date: 1992-02-04
Publication date: 1992-08-26
Also published as: BR9205667A; FI933715A; NZ241707A; EP0573454A1; HU9302318D0; WO1992015128A1; NO933012L; JPH06505119A; FI933715A0; MY130015A; GB9103882D0; AU1221392A; NO933012D0; HUT64646A

Abstract

2103803 9215128 PCTABS00015 An electrical connector, comprising a) a housing comprising a first hollow part and a second part, that can be moved relative to the first part to open and close a space between the first and second parts, b) an electrical switch within the housing that is arranged such that a connection is made automatically on closing said space, optionally when a conductor is located at the first or second part; and c) a sealing material within the space that is substantially entirely enclosed when the space is closed.

Description

wo 92t15128 210 3 ~ 0 3 pcr~Gss2/oo2o8 6~ 1 '' SEALED F~ FCl RIC.~L CONNECI OR

The present invention reilates to ~n environment~llv-se~led electrical connector~ particularly one forming at least part of a ~
telecommunica~ions or other connector block. `

Connec~or blocks may be used in the following way. A
telephone distribution cable~ for example, may contain hundreds of pairs of conductors. It may run from a central office and perhaps after branching one or more times will terminate in a small number of drop wires leading to subscribers. The branches will also end in drop wires to subscribers. These connections between a number of ~ ;
drop wires and the cablei will occur at a distribution point. Also, ~
cables may need to be joined together in a way that allows their ;
conductor interconnections to be rearranged. That occurs at a cross-connection point.
' Rather than have a large number of loose connectors at a distribution or cross-sectional point, it is normal to provide a terminal block or cross-connection block which can be used to connect a number of pairs, such as 3, 5, 10, 25 or 50. Terrninal blocks will normally have incoming conductors perrnanently attached and outgoing conductors removeable; and cross-connection blocks ;
will usually have all conductors removeable. The term "connector block" is used herein generically.

Connector blocks may be used in ground le~el cabinets or pedestals, on a pole, suspended from a wire or mounted on a wall etc, or they may be found in or out of doors.
.
Particularly where they are used out of doors. some form of environmental protection will be desirable. It is especially important : '.
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WO 92tl5128 Pcr/cs92/oo2o8

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to prevent moisture reachinP any electric~l contacts since moisture will impair the signal carried by the conductors connec~ed bv the blo~,~;, and will ultimately lead to corrosion ~nd failure, Prior art terminal blocks in wide use comprise oblong blocks of insulating material having pairs of so-called binding posts passing through them. The binding pOStS extending from the base of the block are connected to the conductors of a distribution cable by, for example, wire wrapping. The conductors and the wire-wrapped posts are then potted in a curing composition making permanent connections. The binding posts also extend above the block and end in a screw thread. Drop wires to subscribers are wrapped around these screw-thread posts, and a nut is screwed over them to form ~
releasable conneclion.

The screw-thrcad posts and nuts corrode, and it was proposed in US 4600261 (Raychem) to protcct thc posts by placing over each of them a cap fillcd with a gel. The gel is said to have a cone penctration value (ASTM D217) from 150 - 350 (10-1 mm), an ultimate elongation (ASTM D638) of at least 200%, a maximum tensile strength of 20 p.s.i., and a cohesive strength greater than its adhesive strcngth. The gel is maintained under compressive contact with the binding posts etc.
~, .
US 4610738 (Raychem) discloses a splice case for electrical conductors comprising first and second containers hinged together.
One~ containcr is slightly larger than the other so that when the splice case is folded shut one container partially telescopes within the other. The containers are filled with a gel.

Mention may also be made of US 4662692 (Raychem) which discloses a termination block sealing member which includes a continuous layer of insulating gel enclosed around its perimeter by a plastics container such that exposed faces of the gel are open. A

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plurality of con~act pins c~n be pierced throu~h ~he gel to make contact with sermin~tions in ~he termirlal bloc~;.

US 4070543 (l`hompson ;lnd Gilliemont) discloses ~ reenter~ble.
waterproof, encapsulated splice ~ssemblv It comprises ~ pair of cup-shaped telescoping housing members containing ;~ gel~ e potting compound.

Use of a grease in an electrical wire connector is disclosed in US
4444447 (3M). A hollow open-topped body telescopes with a cover.
A slotted, flat plate, wire connector is retained on the base of a U-shaped wire cut-off and strain relief element relained centrally within the body.

The disclosure of each of these patents is incorporated herein by reference.

I havc now designed an improved connector that allows good environmental sealing and ease of access to its electrical contacts.

Thus, the present invention provides an electrical connector, comprising:

(a) a housing comprising a first hollow part and a second (preferably hollow) part that can be moved relative to the first part to open and close a space between the first and second part;

(b) an electrical switch (preferably comprising an insulation-displacement connector, particularly of split-beam design) within the housing that is arranged such that a connection is made automatically on closing said space, optionally when a conductor is located at the first or second part;

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c) ~ se~ling m~teri~l. preferably comprising ~ gel. especially in sheet form. within the space. arld preterabl~ subst~nti~llv filling the space. tha~ is substantiallv entirelv enclosed when the space is closed:

(d) optionally a socket accessible from outside the housing, contacts of which are electrically-connected to said electrical switch, th~: socket preferably being sealed by a gel or other sealing material;

(e ) optionally a plug for the socket (d), the plug preferably providing electrical connection between components of said switch via an overcurrent protector and for providing electrical connection between the switch and an electrical ground via an overvoltage protector; and (f) optionally means, such as a spring, for maintaining, and preferably for putting, the sealing material under compression.

The sealing material preferably has the properties mentioned later. ;~

The means for maintaining the gel or other sealing material under compression may comprise a spring or other resilient member, optionally together with a lever, latch or nut and bolt etc. and it may urge ~the first and second parts together.

Tho first and second parts are preferably pivotally-connected, for example by a living or other hinge. In a preferred embodiment the connector comprises first, second and third parts having a cross-section, if pivotally moved to be partially open, substantially the configuration of a letter Z. This is to be regarded as a topological description of the parts~ and it is not necessry that pivoting be ~, WO 92/15128 210 3 8 0 3 PCI'/GB92/00208 ~, . ..

possible to such an ex~enn Wide opening of one or both pairs of ~he parts is. however, preferred.
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The connection in ~he connector housing is prefera~ly made automatically between an insulation-displacement connector ~nd : ' (i) an electrical contact, the connector and/or the contact being resiliently deformable and on moving the first and second parts to close the space being forced together causing one or both to be deformed against its resilience; and (ii) said conductor through insulation thereof, when said conductor is located at the ~lrst or second part.

The invention may additionally or alternatively provide one or more of the following.

An electrical connector having a housing, comprising:

(a) a first part, (b) a second part pivotable about a first line to open and ?
close a space between the first and second parts, and (c) a third part pivotable about a second line of the first part optionally to open and close a space between the first and third parts.

A telecommunications connector block for connecting together first and second conduc~ors, which comprises -(i) a housing comprising ( a ) a hollow first part, and (b) a second part attached to the first part and which can be moved relative to the first part to open and close the housing, .. - . .,. . ,,. ., . .. ~ , . ., . ". . .. .

WO 92/15~81 1) 3 ~ o ~ PCI~/GB92/00208 ~ i ( ii) ~ switch within ~he housing, comprising ( a ) ~ first contact that can be connected to the first conductor, and b) a second contact that can be connecled to the second conductor, the parts and the contacts being so a~anged that opening of the housing automatically opens the switch, and closing of the housing automatically closes the switch.

An electrical connector, which comprises (a) a first part having an electrical contact and means for locating an insulated conductor;
(b) a second part having a split-bcam first insulation-displacement connector, the first and second parts being movcablc relative to one another to open and close a space between them, such that on moving the first and second parts to close thc space the insulation-displacement connector makes electrical contact with (i) an insulated conductor located in the means for locating, contact being made through insulation of the conductor and (ii) said electrical contact.

A split-beam electrical connector, in which the beams at the split are bent between proximal and distal ends thereof.
A spllt-beam insulation displacement connector having a ~; , ' : --~ i~ 2 1 o 3 ~ o ~3 PCJ/GB92/00208 I
configur,~tion such thal insertion ot ~ conductor therein c~uses torsion of at least one the beam.

.~ resilient elect:ric~l connec~or into which ~ conductor may be inserted thereby deforming the connector against its resilience~
mode of deformation of the connector varying with extent of insertion .

An electrical connector having a housing, comprising:

( a ) a first part, ( b ) a second part pivotable about a line adjacent a ~lrst a third part pivotable about a line adjacent a second edge of the first part optionally to open and close a space between the first and third parts; the second edge being adjacent or substantially. opposite the first edge.

An electrical connector which comprises (a) a housing comprising (i) a first part, and (ii) a second part moveable with respect to the first part to open and close the housing;

(b) a first electrical contact carried by the first part; ;:

(c) a second electrical contact or means for locating a conductor carried by the second part, such that when the housing is closed electrical contact is capable of being made between the first contact and either the second contact or the conductor;

(d) electrical ground;

' ' ) U -3 wo 92/15128 pcr/GBs2/oo2o8 . ' e ) means for movin ~he first ;~nd second p~r~s to close the housing, which means is in electnc;ll contact with the electrical ground.

.~n electrical connector. which comprises ( a ) a housing comprising a first part and a second part that can be moved relative to one another~
(b~ an electrical protection device carried by the firs part and being electrically-connectable to a first electrical contact that extends within the housing, (c) a second electrical contact within the housing that has means for connection thereto of an electrical conductor, the first and second electrical contacts being arranged such that connection is made between them on closing the housing and connection between them is broken on openin~
the housing.
.

An electrical connector, which comprises (a) a housing that has means for receiving an electrical protection device.
(b) a first electrical contact having means for connection to a first electrical conductor, (c ) a second electrical contact having means for conncction to a second electrical conductor, and being capable of being in direct electrical contact with the first contac~ in the absence of the protection device;
( d ) the protection device, which when received in the housing interposing an overcurrent protector between the first and second contacts.

For background information, reference may be made to US
4449777, US 4435034, US 4806119, US 4193201, US 4617602, US
4420792, US 4822306, US 4113340, US 4675779, GB 217602, US
4741711, US 4295703, US Bl 37û8779, US 3793612, US 4759723.

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WO 92/1S128 210 3 ~ 0 3 PCI/GB92/00208 , ~ "
IJS 4344664, IJS 3950063. ~nd US ~7641~5. lhe discl~sure of each of which is incorporated herein by reference.

^ The inven~ion is further illustrated with reference to the accompanying drawings, in which :
Figures 1 A and 1 B show two perspective views of an electrical connector of Z-shaped cross-section;
Figure 2 shows lhe connector of figure l in unfolded form;
Figure 3 shows several connectors positioned together to form ?
a terminal block;
Figures 4 and 5 show ways in which connectors can be used to -` join conductors;
Figures 6A, 6B and 6C show the installation of a protection module into a connector;
Figure 7 shows a casing on which connectors may be mounted;
Figures 8, 9, 10 and li show other designs of connector;
Figure 12 shows a connector whose parts slide with respect to onc another, and i Figures 1 3A and 1 3B show an insulation-displacement connector.
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Figures lA and lB show an electrical connector 1, of substantially Z-shaped configura~ion in cross-section, and used to connect together electrical conductors such as telephone wires. Figure lA is a view from above and figure lB is a view from below. Since telephone lines employ pairs of conductors, the connector will in ~eneral have ' one or more pairs of contacts etc. In the following discussion, however, connection of single wires will be referred to for simplicity.

The connector has a first part 2 and a second part 3 pivotable about its rear edge as drawn, thus allowing opening and closing of a space between them. A third part 4 is pivotable about a front edge .

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WO 92/15128 210 3 .i 0 3 PCr/GB92/00208 ~;
'10-ot the first part '~ similarly to allow openin~ ~nd closing of ~ space between then. In generah the first ~nd/or second and/or third p~rts will be at least partiallv hollow. The spaces may contain first and second insulation-displacement or other connectors 5 and 7~ carried preferably by the second and first parts 3 and ~. Such connectors obviate the need for conductors to be pre-stripped at their ends.One or more of the parts (preferably the first and third parts) has means for locating a conductor which may, for example, comprise a hole or recess 6A in an outer surface and/or a protrusion or other guide 6B
within the space between the parts. The parts may pivot about hinges or other means 8 and 9. Living hinges. preferably integral with the parts 2, 3 and 4, are preferred.

The first insulation-displacement connector (IDC) is eiectrically connected to, and preferable is integral with, a first electrical contact 10. The first part 2 carries a second electrical contact, which is clcctrically conncctcd to, and preferable integral with, thc second IDC, 7.

When the first and second parts 2, 3 are closed by pivoting along line 8, the first and second electrical contacts 10, 11 are brought togethcr. They therefore constitute a switch within the connector housing. The result is that the two IDCs 5,7 become electrically connected, thereby joining any conductors carried by them. In this way the connection (say between central office and subscriber) may be made and broken, and if need be the connector may be open and closed without IDC connections being disturbed. ~ -, . ~
This electrical connection between the contacts 1 0, 11 may be direct, or it may require some funher component such as an overcurrent protector between them. In this sense, the connection may be said to be "capable of being made" when the parts 2 and 3 ~` are brought together.

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wo 92~15128 21~ 3 ~ 0 3 pcr/GBs2too2o8 The ~ction of bringing ~ogether Ihe first ~nd second parts ~. 3 or the first and third p~rts ~ 1) may ~lso dnve ~ conductor into the IDC 5 (or 7). This may require a significant force and means may be provided for moving the parts tO close the housing of the connector.
Such means may comprise a bolt that passes through the second (or third) part into a nu~ 12 in the first part 2. The terms "nut" and "bolt" are used herein in a broad sense to include any female/male connector where some turning motion is involved, and includes screws, cams and bayonet fixings. An alternative is an over-centre latch or other lever-action device. `

The housing of the connector may have a cover 13 for enclosing an access point tO the first and second contacts 10, 11, or other component within the housing. Such an access point may allow for testing of thc contacts (for example to de~ermine line voltage or continuity in both or either direction) or for addition of other electrical components. Othcr electrical components may comprise electrical protection such as the overcurrcnt protector mentioned above (in series between the contacts) and/or an overvoltagc protector between onc or both contacts and ground. A further use oS
the access point may be for tapping-off to further telephones, or other telecommunications equipment. Due to the various uses of the `~
access point, it may be referred to as a "fle1~ibility point", providing ;
the connector with increased versatility.
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The access point is preferably environmentally-sealed to ~ -protect ~he contacts 10, 11 or other parts of the connector. Such `
sealing may be provided by a cover 13 and/or by a sealing material such as a gel, particularly one having the following properties: a cone ~`
penetration from 100 - 400, especia!ly 150 - 350, particularly 250 - -350 (l~~ lm~n), an ultimate elongation of at least 100%, particularly ~`
at least 300%, especially at least 500%, a maximum tensile strength~`
of substantially 20 p.s.i, an elastic modulus of less than 107, especially 106, particularly 105 dynes/cm2, and a cohesive strength !~':'.'i:: : ' .: . , ' . . ' ': 'i , , : ` .. . . . .

WO 92/15128 21 0 3 8 0 ~ PCI`/GB92/00208 ~,., i gre~ter than i~s adhesive strenPth to componenlS of the connector.
Cone penetration is determined in accordance with ASTl~l D~ 17-68.
cone weight lû2.5g, shaft weight 47.5g), ~nd elongation in ~cc~rdance with ASTM D638-80.

The. sealing material may be prepared by extending ~
polymeric material with a vegetable and/or mineral oil. The resulting materia~ may be thermoplastic. or it may be formed by cross-linking the polymeric material. The polymeric material may comprise a block copolymer, for example one having c~ystalline end blocks and elastomeric centre blocks. An exarnple is a styrene-ethylene butylene-styrene block copolymer, for exarnple that known by the trade mark Kraton G1651. Such a material may be used with from 700 - 1200, particularly 900 - 1100 parts by weight of plasticizing oil to 100 parts of a block copolymer. Other gels can be ; made based on oil-extended polyurethanes or silicones.

The spaccs between the parts are preferably at least partially filled with such a sealing material, preferably in sheet form. Means, 3 such as a spring, is preferably provided for maintaining and optionally for putting the sealing material under compression.

A device, such as an electrical-protection device, that is applied at the access point is referred to herein in preferred embodiments as a "plug" and a part of the housing that receives it as a "socket".
These terrns are used in a broad sense with reference to the functions of the plug and socket and their relative sizes: whilst we prefer that the plug has male electrical contacts, and the socket female, the situation could be reversed. Also, the second (or other) part of the housing may have a recess within which the plug is at least partially received, but this is not necessary.

Where the plug is tO provide overvoltage protection it will, in general, need to be electrically connected to ground. In this way, it WO 92/lSt28 2 i 0 3 ~ 0 3 PCl/GB92/00208 can shun~ anv overvoltaPe c~used for example by lightning or m~ins vol~age cross away from equipmem connecled by the connector~ ~nd down to ground. The protection device will remain insulating ~I the normal opera~ing voltages of the conductors~ but will become conducling at the higher fault voltage. A ground connection may be , ;~
provided within ~he connector housing and that may be in turn connected to some casing to which the connector is attached. A bolt that closes the part of the housing, and that mates with nut 12 may be in electrical contact with electrical ground. The protection plug ~ s may make contact with the head or other part of the bolt. A
connector housing of slightly different design from that illustrated may then be preferred, so that the bolt and contacts 10, 11 are closer together aDd such that a plug and cover 13 cover both.

The IDCs 5,7 are shown as split beam connectors, and they are more fully illustrated in Figure 13. Their beams are bent at their split between proximal and distal ends. As a result when a `
conductor is inserted into a slit, thc connector, which is preferably resilient, is deforrned against its resilience, thc mode of deformation varying with extent of insenion. Also, energy is stored over a large extent of beam. As a result an IDC of small absolute size, and especially of small size perpendicular to thc plane of the conductors. ~
is able to accept conduc~ors over a large range of sizes. ~.

The connector may be provided with strain relief for the conductors, and/or means for cutting the conductors to length especially on closing of the parts.

Figure 2 shows the connector 1 of figure 1 unfolded such that it lies substantially flat. Preferably the three parts 2, 3, 4 are integral with one another, the part being manufactured by moulding, for example injection moulding. Preferred materials include polypropylene (useful for living hinges) and or various engineering plastics .

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The third part ~ ~or other p~rt~ mav be provided with complemen~ary joining means such as dove-tail protrusion 14 and recess I S whereby a connector can be joined side-bv-side to a similar connector.
~' Figure 3 shows several such connectors joined side-by-side.
Bolts 16 are shown having been used to bring or maintain together various parts of the connectors, and optionally tO provide ground connections.
~, Figures 4 and 5 show two ways in which the connectors 1 can be used to join conductors 17 and 18. The third part 4 acts as a base (hence the use of that part in figure 2 for interconnecion of adjacent connectors) which may be secured to some casing etc. An insulated ~,~-conductor from, for example, a telephone central office, is placed in some mcans for location 6 of the third part 4. This is shown in figure 4A. Thc thîrd part 4 and filrst part 2 are ~hen closed as indicated by the arrow, causing an IDC on the underside of the first part to cut through insulation of the conductor 17 and make electrical contact.

Then a further insulated conductor 18 leading to, for example~
a subscriber, is placed in means for location 6 on the upper surface of the first part 2. See Figure 3. The second part 3 is then closed as shown by the arrow, causing an IDC in the first part tO make connection to conductor 1~. When the second part is closed, the two IDCs make contact with each other, to connect together the conductors 17 and 18, as shown in figure 4C.

Figure S is similar except that in figure SB means for location is provided at the lower surface of the second part 3, and an IDC is provided on the upper surface of the first part 2. -. ., ^ ~, ., , ,~ .. . . - - . , . .~ ....... .. -.. - - .. . . . .

- . . - ; . , -. . .: , : . :.. ~ - : . :

WO 92/15128 21~ 3 ~ 0 3 PCr/GB92tO0208 Figures 6A. 6B ~nd 6C show ~hree steps in the provision of an electrical protection device. or other plug. in a connector.

Figure 6A shows a connector I having a cover 13 that is shown closed. In figure 6B it is open and ~ piug 19 is about to be mated with socket 20. Figure 6C shows the plug, now inserted, covered by the cover which has been folded over it. The cover has a first surface 21 that is now venical (as drawn) and a part 22 that is now horizontal and covers the top of the plug. In this way a cover 13 is provided that can seal socket 20 when empty, and also can seal plug 19. rhus, the connector can be used with full environmental sealing with or without the plug.

A casing 23 is illustrated in figure 7, within or on which are mounted a plurality of connectors 1. Two are shown but more, such as 10, 25 and 50 may be provided. The casing plus connectors may be posidoned in or adjacent a cable splice case, or o~her housing such .
as a cross~onncct cabinet or a pedestal, and i~ may be positioned at ~ ~ ~
ground le~el, on a pole, suspended from a wire or attached to a wall `
etc. The casing 23 may provide a sealed housing or it may compnse `
merely a frame or other support.

The casing 23 illustrated has rails or guides 24 over which connectors I are positioned. The rails 24 may be electrically conductive and connected to ground, thus providing means for grounding some component within the connectors. The bolts 16 may mate with the rails 24. The casing may-have a cover 25 and locating means 26 for the incoming or outgoing conductors. Sealing material 27 may seal the cover to the base.

Figures 8, 9, 10 and 11 show other designs of connectors, each having first, second and third parts 2, 3, and 4 that hinge together.
The designs illustrated are for three pairs of conductors. Two IDCs 5 are provided for each pair (shown) above and (hidden) below the ,, , . ;. ., i - . . ~ .
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WO 92/15128 210 3 8 0 3 PCr/GB92/00208 -16- !

first part ~. A protection plug extends ~hrough socket 0 to connec together ~he contacts 28, optionally via an overcurrem pro~ector and/or to connect either one of them to ground via an overvoltage protector. One of the contacts 28 is integral with the visible IDC 5, ~nd the other extends through the plane of the first part and is integral with the hidden IDC.

Figure 9 shows a drop cable 29 containing three pairs of conductors 30, located in the third part, 4. When the third pan 4 is folded over the first part 2, the conductors are driven into the IDCs S. i A single third part 4 provides for several (here three) pairs of connections.

An opposite side of such a connector is seen in figure 10.
Individual second parts 3 are provided for each pair of connections.
A ground plate 31 is shown below the base of the connector. A bolt for driving thc parts together may be provided, and it may mate with thc plate 31.

In figurc 11 slabs or other sheets of a scaling material 33 are provided between the parts 2, 3 and 4 of the connector. The sheets 33 may be positioned between respective pairs of parts after the conductors have been positioned. Alternatively, the connector may be supplied with a sheet 33 preinstalled at one or more of the appropriate surfaces of the parts. The sealing material preferably substantially fills any space between the parts. Also, it preferably contacts all otherwise exposed connectors or other metal-work within the connector. In this way an excellent environmental seal can be achieved. In less damaging environments, a mere seam seal of sealing material may be sufficient, provided around or adjacen~
peripheries of the parts 2, 3 and 4. Each pair of parts is preferably re-openable, and if a suitable sealing material is used removal and reconnection of central office as well as subscriber conductors is possible.

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WO 92/15128 21 o 3 ~ ~ 3 P~GB92/~208 .

The sealing material preferablv comprises a gel such ~s that mentioned above. .~/leans. such as a sprin~, is preferably provided for maintaining, and optionallv for putting, it under compression. An expansion cavity may be provided into which sealing material may pass on closing the parts and/or on insertion of a conductor.

Figure l 2 shows a connector l having ~lrst, second and third parts 2, 3 and 4 that slide together, preferably telescopically, rather than pivotally. A connector may be provided that combines at least some of the features of a pivoting design and at least some of ~he features of a sliding design.
.. . . .
A conductor 17 from a telephone central office etc passes through a locating means 6 such as a hole in a wall of the first part 2.
When part 4 is slid in the direction of the arrow into, over or , otherwise with respec~ to part 2 the conductor 17 is driven into IDC
7.
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A subscribcr drop wire 18 is located in means 6 of the first part 2 and is likewise driven into IDC 5 by sliding the part 3 into, over or otherwise with respect to part 2. Contacts 10 and 11, which are connectcd to (and preferably integral with) IDCs 5 and 7, are themselves connected together by plug 19 on insertion thereof into socket 20. As mentioned in connection with the designs above, plug 19 may connect contacts lO, l 1 via an overcurrcnt protector and/or may connect either of them to ground via an overvoltage protector.

A bent IDC S is shown in figure 13A. The IDC is of the split-beam type ha~ing beams 34 and slot 35 between them. The IDC
preferably comprises a phosphor-bronze or beryllium-copper alloy.
In particular, IDCs (especially those for incoming wires from a central office) comprise a 0.5 to 0.75 hard phosphor-bronze C51000 or C5l900 which are nominally Cu-SnS and Cu-Sn6. Such materials have good elasticity without excessive stress-relaxation. IDCs for . . .
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WO 92/lS128 2 ~ a 3 ~, O i~ PCr/CB92/00208 drop wires to subscribers, which may be re-en~ered more often, may have more stringent requirements of elasticity, ductility (allowing sharp bends) and hardness. The material preferably has a yield s~ess of at least 300, especially 350 MPa. and is preferably hard enough to deform bronze and steel wires. If its conductivity is not sufficient, it may be plated. The drop IDC preferably comprises Cu- -Sn8 C52100 hard, Cu-SnlO 52400 hard, Cu-Sn5 C5100 hard or Cu-Sn6 C51900 hard. In general, we prefer a modulus of 90000 - ¦
1 40000, especially abou~ 11 0000 MPa, and a tensile strength of greater than 400 especially 450 MPa. The ductility preferably allows the material to be bent at a radius of the material thickncss, or greater than 5%. Hardness is preferably at leass 70, especially 72 Rockwell B. An example of a beryllium-copper alloy is C17200, which may require hardening by heat treatment. A spinoidal alloy such as Cu-Ni-Sn C72700 may be suitable. The beams 34 at the split 35 are bent between a distal end and a proximal end thereof. Thus, the slit extends as it were around the bend. Preferably the beams have a substantially planar first part 36 distal of the bend and a substantialiy planar second part 37 pro~cimal of the bend. The slit may terrninate at a cut away portion 38 to avoid stress concentration. Thc IDC is shown mounted on a support 39. On insertion of conductor 17 into the slit 35 as shown by arrow A the initial deformation of the beams will be predominantiy as shown by arrows B. This involves torsion of the proximal parts 37 as shown.
As the conductor advances in the slot 35 between the distal parts 36 the mode of deformation will vary to become predominantly bending of the proximal parts 37 as shown by the arrows C.

The length D of the second part is preferably 10-20, particularly 12-i6, especially about 14 mm, and that (E) of the whole horizontal part is preferably 25-30 mm. The width F of the IDC is preferably 5-10, especially about 8 mm, the slit being preferably 2.5

- 4.5 mm at the second part and sharpened edges of the beams preferably substantially touching one another at the distal part 36.

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WO92/15128 2.t~3 ~? O ~ PCI/GB92/00208 1 ~
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~`, The length G of the distal p~rt is preferably 6 - 14, especially 8 - 12, particularly about 10 mm. Preferably, the length D is from 1.2 - 1.6, pa~ticularly about 1.4 times the length G. The material thickness of the IDC wil1 typically be from 0.8 - 1.2, especially about 1 mm.
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Figure 13B is an end view of an IDC of the type shown in figure 1 3A. Here, however, the IDC is provided with stop means 40 which may be part of a support 39 or a connector housing. Stop means 40 sen~es to lin~it free deforrnation of thc IDC. Thus, for larger conductors some deformation of stop means 40 will additionally be required, thus increasing the force exerted by the IDC on the larger conductors.

For the avoidance of doubt it is noted that the invention -provides an improved connector, IDC, connection block and mothod of connection. Any of thc conncctors, IDCs, contacts, housing or casing designs or protector designs may bc sclccted.

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Claims

1. An electrical connector comprising (a) a housing comprising a first hollow part and a second part, that can be moved relative to the first part to open and close a space between the first and second parts, (b) an electrical switch within the housing that is arranged such that a connection is made automatically on closing said space, optionally when a conductor is located at the first or second part; and (c) a sealing material within the space that is substantially entirely enclosed when the space is closed.

2. An electrical connector according to claim 1, in which the electrical connector comprises an insulation-displacement connector.

3. An electrical connector according to claim 2, in which the connector comprises a split-beam connector.

4. An electrical connector according to claim 2 or 3, in which connection is made automatically between the insulation-displacement connector and (i) an electrical contact, the connector and/or the contact being resiliently deformable and on moving the first and second parts to close the space being forced together causing one or both to be deformed against its resilience; and (ii) said conductor through insulation thereof. when an insulated said conductor is located at the first or second part.

5. An electrical connector according to any preceding claim, in which the first and second parts are pivotally connected to one another.

6. An electrical connector according to any preceding claim, in which the space when closed is substantially filled with the sealing material.

7. An electrical connector according to any preceding claim, in which the sealing material is in substantially sheet form.

8. An electrical connector according to any preceding claim, in which the sealing material comprises a gel.

9. An electrical connector according to any preceding claim.
in which the sealing material has a cone penetration, as determined by ASTM D217-68, of from 100 - 400 (10-1mm) and an ultimate elongation, as determined by ASTM D638-80, of at least 10%.

10. An electrical connector according to any preceding claim, which additionally comprises (d ) a socket accessible from outside the housing, contacts of which are electrically-connected to said electrical connector.

11. An electrical connector according to claim 10, which additionally comprises (e) a plug for the socket (d).

12. An electrical connector according to claim 11, in which the plug provides electrical connection between components of said switch via an overcurrent protector.

13. An electrical connector according to claim 11 or 12, in which the plug provides electrical connection between the switch and an electrical ground via an overvoltage protector.

14. An electrical connector according to claims 11, 12 or 13, in which insertion of the plug in the socket breaks a direct electrical connection between components of the switch.

15. An electrical connector according to any of claims 10 - 14, in which the socket is environmentally sealed with a sealing material.

16. An electrical connector according to claim 15, in which the sealing material comprises a gel.

17. A connector block comprising a plurality of connectors according to any preceding claim and optionally a connector block casing.