GB2284510A

GB2284510A - Electrical connector

Info

Publication number: GB2284510A
Application number: GB9424543A
Authority: GB
Inventors: Wolfgang Pfeiffer
Original assignee: Interconnectron GmbH
Current assignee: Interconnectron GmbH
Priority date: 1993-12-04
Filing date: 1994-12-05
Publication date: 1995-06-07
Anticipated expiration: 2014-12-05
Also published as: GB9424543D0; FR2713408A1; GB2284510B; IT1275681B1; ITMI942445A1; FR2713408B1; ITMI942445A0

Abstract

An electrical connector has a cylindrical casing (1), a plug/socket part (2) positioned therein, an adaptor nut (3) and a screw on end cap (4). The screw on end cap (4) is assembled onto the casing (1) to contain within it a clamping cage (5), a ring seal (6), a contacting component (7) for the cable shield and a support ring (27). The contacting component (7) is designed to engage via its catch lugs (17) with the inner wall (18) of the casing (1). A radially inward protruding rib on the inner wall (18) of the casing (1) prevents the contacting component (7) from rotating while the end cap (4) is screwed into position. This prevents any damage being caused to the connector or cable during assembly. The clamping cage (5) offers strain relief for a wide range of cable diameters. On assembly the connector is completely sealed by sealing components (6) and (31) and electrically coupled to the cables shield over its entire length. An alternative construction (Fig. 5) has a contacting element (7) comprising a circumferential flat spiral spring, held between a locking ring and an outer ring. <IMAGE>

Description

ELECTRICAL CONNECTOR The present invention relates to an electrical connector comprising an essentially cylindrical casing accommodating a male or female part and an end cap, which may be screwed onto said casing and is sealed in relation thereto by means of a seal, wherein at least one seal abutting the cable jacket, a strain relief means for the cable jacket formed by a clamping cage, as well as a contacting means for a cable shield with the casing in the form of a ring-shaped arrangement, are disposed in the connector.

Electrical connectors generally consist of a first and second casing half accommodating a respective male or female part , in which in at least one of the casing halves a seal and a strain relief means combined therewith for the cable jacket as well as a contacting means for the cable shield with the connector casing composed of a circumferential (flat spiral) spring and a clamping ring engaging in said spring are disposed. In this arrangement, at least one of the two casing halves consists of an essentially cylindrical casing and a screw-on end cap, such that when the connector is assembled, the casing is partially covered by the screwon end cap, which receives the contacting means for the cable shield and the seal and strain relief means, and is generally also sealed with respect to the casing.

In these known connectors, the seal of the cable jacket formed by a ring seal as well as the clamping cage and possibly also the contacting means to the electromagnetic shield of the cable are disposed partially inside the screw-on cap and partially in the casing or engaging in the casing, and are held to abut one another by means of the screwed-on cap and pressed against the casing. The consequence of this is that the end cap is tightened up against a certain deformation resistance of the flexible parts such as the ring seal and clamping cage, when screwing onto the casing.

Because of this, there is no defined tightening moment for the end cap, and moreover independently of this, it is be expected that the sealing parts made from elastomer material will suffer permanent deformation in the course of time resulting in the screw connection of the end cap loosening somewhat.

In many cases, the fact that the end cap must be screwed onto the casing to produce compression of the flexible parts such as the ring seal and clamping cage, causes the contacting means to be drawn along with it so that as the end cap is screwed on, the contacting means, which is positively engaged with the cable jacket and the cable shield, is simultaneously rotated around the cable axis, thus causing it to be extensively damaged, possibly partially destroyed, by the cable shield and cable jacket. Damage caused to the cable is particularly serious as it cannot be recognised during assembly of the connector, and therefore the fault only becomes evident after completion of the cable assembly and possibly even after installation. This results in considerable expense being incurred because a new connector has to be attached to the cable, but may even cause the entire cable to be renewed, for example, because its predetermined length does not allow for it to be shortened as is necessary for attachment of a new connector.

An object of the invention is to further improve an electrical connector of the type described above so that it may be manufactured at the lowest possible expense for a wide range of applications, assembled in the simplest manner and to ensure that when the casing and end cap are screwed together, there is no possibility of damage to the cable shield or cable jacket, and that when the connector is screwed together, the screw joint between the end cap and the casing cannot automatically loosen, even after long periods of time. In addition, the connector should be constructed so that its clamping cage may fit a wide range of cable diameters.

This object is primarily achieved according to the invention in that the contacting means for the electromagnetic shield of the cable may be coupled nonrotatably to the casing of the connector and at the same time a support ring abutting the free face of the cylindrical casing is allocated to the contacting means, and said support ring on the one hand abuts against a shoulder constructed obliquely to its longitudinal direction of the inner periphery of the end cap and via at least one portion of its periphery abuts conductively against the inner periphery of the end cap, and on the other hand abuts conductively against the free face of the cylindrical casing at least by means of the contacting means, said support ring also forming at least one axial support for the ring-shaped contacting means.

The non-rotational coupling according to the invention of the contacting means with the casing of the connector prevents the contacting means by positive engagement with the connector from rotating in relation to the cable shield or cable jacket when the casing and end cap of the connector are screwed together. This also excludes the possibility of any damage being caused to the cable shield or cable jacket when the connector is being screwed together. In addition, because according to the invention the end cap and metal parts of the built-in components are constructed and arranged in such a way that the built-in components abut one another directly when the end cap is screwed on and abut against the two connector parts - the casing and end cap - in a form-locking manner, this provides a continuous rigid metal support extending over the entire length of the connector between the casing, contacting means and cap so that once the tightening force has been established during assembly, it does not change over time. The circumstance associated with the conventional inclusion of flexible sealing elements or other non-metallic components, in particular built-in components of the connector, i.e. that the non-metallic, flexible parts are liable to deform with the consequence that the screw joint between the casing and the end cap loosens after a certain time, is thus avoided. A particular advantage is that the connector is easily assembled and does not require any additional or complex components, and moreover also permits the use of all conventional sealing elements. Another is that all the casing parts are conductively connected over the entire connector, which is particularly advantageous for electromagnetic shielding.

It is generally possible to also provide that the end cap and the metal parts of the contacting means have an outside diameter greater than the inner periphery of the casing, and are constructed and arranged in such a way that, when the end cap is screwed-on, they form a rigid metal support between it and the casing in such a way that they abut one another, as well as abutting the end cap on the one hand and the casing body on the other hand, either directly or indirectly over their surface.

The invention also expediently provides that a clamping cage of variable width, a ring seal and the contacting means for a cable shield are arranged one behind the other in the direction of cable entry inside the screwon end cap, the outside diameter of the base section of the clamping cage the inside end of the ring seal each being smaller than the outer diameter of the casing.

According to a first arrangement constituting a preferred embodiment of the invention, the contacting means comprises a ring-shaped flat blank provided with radially inward protruding claws and at least one axial catch element to secure it against rotation in relation to the cylindrical casing. In this case, the ring-shaped flat blank forming the contacting means may advantageously have axially angled guide lugs adjoining its outer periphery in a first direction and axially angled catch lugs adjoining its inner periphery in a second direction, in which case the inner periphery of the ring-shaped flat blank forming the contacting means corresponds at least approximately to the inner width of the cylindrical casing, such that the catch lugs disposed therein engage in the cylindrical casing when the connector is assembled to abut against its inner peripheral wall.

This embodiment also provides that a coding means constructed on the inner periphery of the cylindrical casing and formed by a radially inward protruding rib is allocated to the axially angled catch lugs of the ringshaped contacting means as mating catch element for a socket insert to be disposed in said casing, so that the non-rotatable fixture of the contacting means to the casing requires no further expense or special attention from the assembly personnel, either with respect to manufacture, to installation of the contacting means, or to the assembly of the connector.

To further facilitate or simplify assembly of the connector, this embodiment additionally provides that a shoulder constructed on the inner face of the support ring is allocated to the ring-shaped portion of the contacting means in the form of a bearing surface or abutment so that the axially angled guide lugs disposed on the outer periphery of the ring-shaped portion of the contacting means and opposed to the catch lugs engage in a cavity between the support ring and the inner periphery of the cap when the connector is assembled. Thus, in the course of the assembly of the connector, all parts to be accommodated therein may simply be inserted one after the other in the end cap before it is screwed to the casing.

According to a second embodiment of the invention characterised by the use of a contacting means for the electromagnetic shielding of the cable comprising a circumferential flat spiral spring and at least one locking ring engaging therein, the contacting means for the cable shield is provided with means for coupling it non-rotatably to the casing and with an outer ring abutting the free face of the cylindrical casing, in which case a support ring forming a support on the inside end is allocated to the locking ring of the contacting means so that the outer ring and the support ring abut one another via their faces as well as abutting the casing on the one hand and a shoulder constructed obliquely to its longitudinal direction on the inner periphery of the end cap on the other hand.

As regards the means for coupling the contacting means non-rotatably to the casing, there are various possible constructions, for example, axial projections or recesses may be provided on at least one portion of the contacting means which cooperate with allocated projections or recesses in the outer ring or in the casing in the manner of a claw coupling.

According to another advantageous embodiment, which in particular reduces the number of individual parts required and thus simplifies assembly, the locking ring of the contacting means has a profile cross-section which is generally approximately in the form of a Z, such that it is provided with an axial extension, which adjoins a radial extension zone relative to the axis of the connector and forms a support ring, and by means of this encloses the ring seal. In a further variation of this feature, the axial extension of the locking ring forming the support ring and enclosing the ring seal is also expediently constructed so that it extends conically towards the casing in such a way that it also forms a tapered collar, which applies a radial pressure onto the ring seal. In this way, in the course of assembly of the connector, the ring seal is also automatically pressed onto the cable jacket in particular without requiring any further parts, or any special construction of the cap or similar expensive measures.

According to another advantageous embodiment according to the invention, the clamping case is constructed within broad limits so as to be adaptable to various cable diameters, which is achieved in an advantageous manner by constructing the clamping cage in two parts so that both parts thereof may be interlocked.

A further possible measure is that the clamping cage is composed of a larger covering part and a smaller part engaging therein, the engaging part of the clamping cage having a circumferential axial catch recess on its continuous circumferential base section and the covering part of the clamping cage having a catch tab corresponding in shape to the cross-section of the catch recess on the base section of the engaging part of the clamping cage. This arrangement of the clamping cage allows it to be adapted to a very wide range of different cable diameters, enabling the clamping cage to be adapted to a particular cable diameter by attaching or removing the inner engaging clamping cage part.

Finally, a seal in the form of a radial seal can be disposed between the casing and the end cap, which may be screwed onto said casing, which is made possible by the measure that the screw-on end cap is provided with a radially directed inner peripheral recess in the vicinity of its free face end and a sealing element arranged therein is formed by an O-ring.

The invention is explained below in the following description of the Figures on the basis of two examples shown in the drawing.

Figure 1 shows a partially cut-away lateral view of a first embodiment of a connector according to the invention; Figure 2 shows a schematic representation of the contacting means illustrating its position inside the connector; Figure 3 shows a lateral view of the contacting means; Figure 4 shows a top view onto the flat blank forming the contacting means; Figure 5 shows a partially cut-away lateral view of a second embodiment of a connector according to the invention.

Both electrical connectors shown in the example are essentially composed on a basically cylindrical connector casing 1, a socket insert 2 disposed therein and only shown schematically here, an adapter nut 3 and a screw-on end cap 4, and inside said screw-on end cap a clamping cage 5, a ring seal 6 and a contacting means 7 for the cable shield of a cable (not shown in detail) are disposed. The end cap 4 has a first longitudinal section 9 adjoining a cable entry opening 8 and a second longitudinal section 10 adjoining the first, said second longitudinal section 10, with the formation of an axial shoulder 11, having a larger inside diameter than said first longitudinal section 9. The inside diameter of the said first longitudinal section 9 is smaller than the outside diameter of the cylindrical casing 1 and the inside diameter of the second longitudinal section is equal to or larger than the outside diameter of the casing 1.

A support ring 27, which is provided for at least axial support of the contacting means and supported in axial direction against the shoulder 11 of the end cap 4, encloses the ring seal 6 and has a cross-sectional form extending conically towards the casing 1, which at the same time allows the ring seal 6 to be pressed or compressed radially onto the cable jacket during the course of assembly of the connector. The clamping cage 5 disposed in the first longitudinal section 9 of the end cap 4 is constructed in two parts and comprises a first covering part 120 and a second engaging part 121, the interlocking arrangement of the two parts 120 and 121 of the clamping cage being shown in the example. The first covering part 120 of the clamping cage has a ring 124 of clamping lugs adjoining a base section 126 and is provided with a circumferential locking tab 125 in the vicinity of the bases of the clamping lugs in the ring 124. The second engaging part 121 of the clamping cage also has a ring 127 of clamping lugs adjoining a base section 126 with a correspondingly smaller diameter, and is provided with a circumferential catch groove 28 in the vicinity of the bases of the clamping lugs in the ring 127, the cross-section of said catch groove corresponding to the cross-section of the locking tab 125. When the connector is assembled, the end cap 4 is sealed with respect to the casing 1 by means of a radial seal. For this, the end cap 4 is provided with a radial recess 30 in the vicinity of its inner face end, an O-ring 31 being arranged to sit in this radial recess 30 and to abut under pressure against the outer peripheral of the casing 1.

In the first embodiment shown in Figures 1 to 4, the contacting means 7 consists of a ring-shaped flat blank 12 provided with radial 1'! inward protruding claws 13 engaging the cable shield and with at least one axial catch element to secure it non-rotatably to the cylindrical casing 1. The ring-shaped flat blank 12 forming the contacting means 7 has axially angled guide lugs 15 adjoining its outer periphery in a first direction and axially angled catch lugs 17 adjoining its inner periphery 16 in a second direction, in which case the inner periphery of the ring-shaped flat blank 12 forming the contacting means corresponds at least approximately to the inner width of the cylindrical casing 1 in such a way that when the connector is assembled, the catch lugs 17 engage in the cylindrical casing 1 to adjoin the inner peripheral wall 18 of said connector. A coding means constructed on the inner periphery 18 of the cylindrical casing 1 and forming by a radially inward protruding rib 19 is allocated to the axially angled catch lugs 17 of the ring-shaped contacting means 7 as mating catch element for a socket insert 2 to be disposed in said casing in order to automatically assure the non-rotatable fixture of the contacting means 7 to the casing 1 as soon as one of the catch ribs 17 comes into abutment against one of the flanks of the rib 19. Hence, no further expense or special attention from the assembly personnel is required, either with respect to manufacture, to installation of the contacting means, or to the assembly of the connector. A shoulder 21 constructed on the inner face of the support ring 27 is allocated to the ringshaped portion 20 of the contacting means 7 in the form of a bearing surface or abutment so that the axially angled guide lugs 15 disposed on the outer periphery of the ring-shaped portion 20 of the contacting means 7 and opposed to the catch lugs 17 engage in a cavity 22 between the support ring 27 and the inner periphery 10 of the end cap 4 when the connector is assembled. Thus, in the course of the assembly of the connector, all parts to be accommodated therein (clamping cage 5, ring seal 6, support ring 27 and contacting means 7) may simply be inserted one after the other in the end cap 4 before this is screwed to the casing 1. In this case, when these are being screwed together, the contacting means 7 engaging with the cable shield via the claws 13 comes into abutment against the rib 19 of the casing 1 via one of its catch lugs 17 and is thus automatically secured against further rotation around the cable axis.

In the embodiment shown in Figure 5, the contacting means 7 for the shield of the cable and an outer ring 112 with an essentially Z-shaped cross-section are disposed one behind the other in the second longitudinal section 10 of the end cap 4. In this case, the contacting means 7 comprises a circumferential flat spiral spring 113 and a locking ring 114 engaging therein. A locking ring 114, which also has an approximately Z-shaped cross-section encloses a radially extending extension zone 116 to adjoin a cylindrical ring segment 115; engaging in the flat spiral spring 113 and also encloses an axially directed support ring 27 adjoining this extension zone 116, and is arranged with the support ring 27 to lie on the shoulder 11 in the end cap 4. The outer ring 112 engages in the casing 1 with a first axial section 118, and is supported on the support ring 27 of the locking ring 114 via a second section 119 displaced outwardly in relation to the first section.

Claims

1. An electrical connector comprising an essentially cylindrical casing accommodating a male/female part, and an end cap, which may be screwed onto said casing and is sealed in relation thereto by means of a seal, wherein at least one seal abutting the cable jacket, a strain relief means for the cable jacket formed by a clamping cage, as well as a contacting means for a cable shield with the casing in the form of a ring-shaped arrangement, are disposed in the connector, the contacting means for the cable shield may be coupled non-rotatably to the casing and at the same time a support ring abutting the free face of the cylindrical casing is located to the contacting means and said support ring on the one hand abuts against a shoulder constructed obliquely to its longitudinal direction on the inner periphery of the end cap and via at least one portion of its periphery abuts conductively against the inner periphery of the end cap and via at least one portion of its periphery abuts conductively against the inner periphery of the end cap and on the other hand abuts conductively against the free face of the cylindrical casing at least by means of the contacting means, said support ring also forming at least one axial support for the ring-shaped contacting means.

2. A connector according to Claim 1, wherein the end cap and the metal parts of the contacting means have an outside diameter greater than the inner periphery of the casing and are constructed and arranged in such a way that, when the end cap is screwed-on, they form a rigid metal support between it and the casing in such a way that they abut one another, as well as abutting the end cap on the one hand and the casing body on the other hand over their surface.

3. A connector according to Claims 1 and 2, wherein a clamping cage of variable width, a ring seal, support ring and the contacting means for a cable shield are arranged one behind the other in the direction of cable entry inside the screw end cap, the outside diameter of the clamping cage and the inside end of the ring seal each being smaller than the outer diameter of the casing.

4. A connector according to Claims 1 to 3, wherein the contacting means comprises a ring-shaped flat blank provided with radially inward protruding claws and at least one axial catch element to secure it against rotation in relation to the cylindrical casing.

5. A connector according to Claims 1 to 4, wherein the ring-shaped flat blank forming the contacting means has axially angled guide lugs adjoining its outer periphery in a first direction and axially angled catch lugs adjoining its inner periphery in a second direction.

6. A connector according to Claims 1 to 5, wherein the inner periphery of the ring-shaped flat blank forming the contacting means corresponds at least approximately to the inner width of the cylindrical casing, such that the catch lugs disposed therein engage in the cylindrical casing when the connector is assembled to abut against its inner peripheral wall.

7. A connector according to Claims 1 to 6, wherein a coding means. constructed on the inner periphery of the cylindrical casing and formed by a radially inward protruding rib is allocated to the axially angled catch lugs of the ring-shaped contacting means and mating as mating catch element for a socket insert to be disposed in said casing.

8. A connector according to Claims 1 to 7, wherein a shoulder constructed on the inner face of the support ring is allocated to the ring-shaped portion of the contacting means in the form of a bearing surface or abutment so that the axially angled guide lugs disposed on the outer periphery of the ring-shaped portion of the contacting means and opposed to the catch lugs engage in a cavity between the support ring and the inner periphery of the end cap when the connector is assembled.

9. A connector according to one of Claims 1 to 3, its contacting means comprising a circumferential flat spiral spring and at least one locking ring engaging therein, the contacting means for the cable shield is provided with means for coupling it non-rotatably to the casing and with an outer ring abutting the free face of the cylindrical casing, in which case a support ring forming a support on the inside end is allocated to the locking ring of the contacting means so that the outer ring and the support ring abut one another via their faces as well as abutting the casing on the one hand and a shoulder constructed obliquely to its longitudinal direction on the inner periphery of the end cap on the other hand.

10. Connector according to Claim 9, wherein the locking ring of the contacting means has a profile crosssection which is generally approximately in the form of a Z, such that it is provided with an axial extension, which adjoins a radial extension zone relative to the axis of the connector and forms a support ring, and by means of this encloses the ring seal.

11. A connector according to Claims 9 and 10, wherein the axial extension of the locking ring forming the support ring is constructed so that it extends conically towards the casing.

12. A connector according to Claims 9 to 11, wherein the clamping cage is constructed in two parts so that both parts thereof may be interlocked, wherein the clamping cage is composed of a larger covering part and a smaller part engaging therein, the engaging part of the clamping cage having a circumferential axial catch recess on its continuous circumferential base section and the covering part of the clamping cage having a catch tab corresponding in shape to the cross-section of the catch recess on the base section of the engaging part of the clamping cage.

13. A connector according to Claims 1 to 12, wherein a seal in the form of a radial seal is disposed between the casing and the end cap which may be screwed onto said casing.

14. A connector according to Claims 1 to 13, wherein the screw-on cap is provided with a radially directed inner peripheral recess in the vicinity of its free face end and the sealing element is formed by an O-ring.

15. A connector according to Claims 1 to 14, wherein the outer ring and the locking ring of the contacting means each have an approximately Z-shaped cross-section.

16. A connector substantially described with reference to and as illustrated in Figure 1 or 2 or Figure 3 and 4 of the accompanying drawings or Figure 1 as modified by Figure 5 of the accompanying drawing.