The invention relates to an accessory, in particular of the “backshell” type, designed to be assembled to a connector. Such an accessory is, in particular, designed for the attachment of one or more electrical cables to the connector.
Conventionally, an accessory comprises a main body whose general shape is substantially cylindrical and a lock nut locked axially relative to the main body by means of a retention ring.
The nut is designed to be fixed to a thread of a circular connector.
In order to prevent rotation between the accessory and the connector, these parts are also conventionally provided with teeth capable of interlocking with one another when they are axially brought together by the screwing of the nut onto the connector.
Most of the accessories mounted on circular connectors achieve an axial electrical contact at the interface between the teeth of the accessory and the teeth of the connector. Certain teeth may however not be in contact or have a reduced contact surface with the teeth between which they are placed.
In the event of a lightning discharge, devastating electric arcs may then form between the teeth of the accessory and the teeth of the connector if there is not a clear contact between them.
To limit this formation of electric arcs, other accessories are known that are provided with metal lugs capable of ensuring, by elastic pressure, a substantially radial electrical contact at a lateral surface of the connector, with the connector. The incorporating of such contact lugs is for example described in U.S. Pat. No. 5,580,278.
The quality of the electrical contact provided by these contact lugs depends on the pressure that they apply to the lateral surface of the connector. However, any increase in this pressure leads to making it more difficult to couple the accessory to the connector, the operator then having to apply an increased axial force to insert the connector between the contact lugs.
There is therefore a need for an accessory capable of being assembled to a connector, in particular a circular connector, that is capable of providing effective protection in the event of a lightning discharge and which is easy to assembly to the connector.
The object of the invention is to satisfy this need.
According to the invention, this object is achieved by means of an accessory designed to be assembled to a connector on an assembly axis D, comprising:
a main body, and
The accessory according to the present invention is noteworthy in that it also comprises pressure means capable of deforming the contact element so as to be able to increase said pressure applied by the contact portion.
As will be seen in greater detail in the rest of the description, the accessory according to the invention may therefore comprise a contact element that opposes not at all, or very little, axially bringing the main body of the accessory and the connector closer together. The axial force that the operator has to apply when assembling the connector and the accessory therefore remains weak. Furthermore, the pressure on the conductive surface of the connector applied by the contact element is not limited to that resulting from its elasticity. At an appropriate moment, and particularly during or after the assembly operations, the pressure means make it possible to push the contact portion. By determining the conditions in which the pressure means will apply this pressure, it then becomes possible to ensure a higher contact pressure without this pressure making it more difficult to couple the accessory to the connector.
The accessory according to the invention may also comprise one or more of the following optional features:
In a first embodiment, the ring and the main body are made so that said pinching can deform the contact element in a manner tending to increase said pressure applied by said contact portion. If said pressure is centripetal, that is to say comprises a component oriented towards the axis D, the deformation may, for example, tend to move said contact portion toward the axis D. Accordingly, in the region of pinching of the contact element, the ring and the main body may for example have, in cross section, convex and concave shapes respectively. Any shape allowing the pinching to cause a rotation of the lug toward the axis D would however be appropriate.
In a second embodiment, which is not incompatible with the foregoing, the contact element and the radial locking means are made so that a movement, for example axial and in the direction of the connector, of the radial locking means relative to the main body causes the radial locking means to push the contact portion of the electrical contact element in a direction tending to increase said pressure applied by said contact portion.
The invention also relates to a connection assembly comprising a connector, for example a circular connector, and an accessory designed to be assembled to this connector. This assembly is noteworthy in that the accessory complies with the invention.
This connection assembly may also comprise one or more of the following optional features:
In the first embodiment of the accessory, the radial locking means of the accessory are preferably made so that their activation can cause said pinching of said base between the ring and the main body of the accessory by pressure of the connector on the ring, said pinching deforming the contact element in a manner tending to create and/or increase said pressure applied by said contact portion.
In the second embodiment, the radial locking means of the accessory on the connector can be moved relative to the main body, after the ring has come into abutment with the connector. Preferably, the contact element and the radial locking means are made so that a movement of the radial locking means relative to the main body, for example on the axis D and in the direction of the connector, leads to the radial locking means pushing toward the axis D at least the contact portion, while the ring remains abutted against the connector. This movement of the locking means may preferably allow an adjustment of the pressure of the pressure means on the electrical contact element, and hence an adjustment of the pressure applied by the electrical contact element on the lateral contact surface of the connector.
The invention also relates to a method for assembling an accessory to a connector, the accessory comprising at least a deformable contact element of which at least a portion of electrical contact may be placed opposite an electrically conductive surface, for example a lateral surface, of the connector, the method comprising the following steps:
This method may also comprise one or more of the following optional features:
Other features and advantages of the invention will also appear in the description of the drawing supplied for descriptive purposes and being in no way limiting. In this drawing:
a and 4b represent, in longitudinal section, an assembly according to the invention in a second embodiment, before and after activation of the pressure means, respectively.
In the various embodiments, the reference numbers are chosen to be identical in order to designate identical or similar members. In the second embodiment, they are however given a prime sign.
In the following description, the parts are described with reference to
Unless specified otherwise, “axially” means “on the axis D”.
“Lateral surface” means a surface extending substantially parallel to the axis of assembly of the connector and the accessory.
“Radial locking means” of the main body relative to a connector refers to means capable of preventing any relative movement between these two parts in a direction perpendicular to the axis of assembly D, that is to say means allowing only a relative movement along this axis.
The axis of assembly is the main direction followed by the connector and the accessory when they are assembled. Conventionally, this axis, during assembly, is indistinguishable from the longitudinal axis of the connector and from that of the accessory.
“Deformable contact element” means a contact element which may be deformed by hand, in a manner that is visible to the naked eye. Preferably, the contact element comprises a lug one end of which is free and the other of which is attached to a base. It is then considered that the contact element is deformable when the possible movement of the free end, by manual deformation, is greater than 5%, preferably is approximately 10% of the distance between the two ends of the lug.
A first embodiment is shown in
The main body 20 may be made of a conductive material or may be covered with a layer made of a conductive material.
At a first end of the main body, an annular groove 22 is made on the external lateral surface of the main body 20. The edge 24 of the main body 20, on the side C, comprises a plurality of housings 25.
The groove 22 is designed to accommodate a retention ring 40. Accordingly, the retention ring 40 is interrupted and has sufficient elasticity to be deformed when it is installed in the annular groove 22, then to substantially revert to its initial shape.
As shown in
The nut 30 also has an annular groove 32 that can be placed opposite the annular groove 22 of the main body 20, as shown in
The accessory according to the invention also comprises a ring 50 allowing a rotary coupling of the main body 20 and of the connector to be assembled to the accessory. Accordingly, the ring 50 has tenons 52 extending substantially axially and capable of entering the housings 25 of substantially matching shapes made in the edge 24 of the main body 20. The insertion of the tenons 52 into the housings 25 prevents any rotation of the main body 20 relative to the ring 50.
On the side opposite to the tenons 52, the ring 50 has a toothed portion consisting of a plurality of substantially axial teeth 54. These teeth 54 are made so as to mesh with matching teeth made on the connector.
On the side A, the ring 50 has a face 56 which, in longitudinal section, has a convex profile. In other words, the face 56 of the ring 50 has a convex semi-toric shape.
Preferably, the ring 50 is made of an electrically insulating material, which advantageously makes it possible to remove any formation of an electric arc on the teeth 54 and 100.
The accessory 10 according to the invention also comprises a bracelet 60 formed of a plurality of lugs 62 extending substantially parallel to the axis D and connected to one another via a common base 64 extending substantially on a transverse plane, that is to say perpendicular to the axis D.
The lugs 62 extend mainly along a notional cylinder with an axis D. In cross section, as shown in
The bracelet 60 may be made of an electrically conductive material or covered, at least partly, with an electrically conductive material so as to ensure an electrical connection at least between the contact portion 70 and a portion of the bracelet 60 in contact, after the accessory has been assembled with the connector, with the main body 20.
On the side opposite to the lugs 62, the base 64 has a rim 72 extending substantially along a notional cylinder with an axis D. All of the lugs 62, the base 64 and the rim 72 thereby define a substantially axial annular groove capable of accommodating the ring 50, as shown in
The base 64 has orifices or notches, not shown, that the tenons 52 can pass through so that the latter can be housed in the housings 25 of the main body 20.
The edge 24 of the main body 20 has, at least in the region of pinching of the bracelet 60 with the ring 50, a concave semi-toric section.
The connector 90 has a stepped cylindrical shape.
In the direction A of the accessory 10, the connector 90 has successively:
The thread 93 is able to interact with the internal thread 34 of the nut 30.
The conductive surface 96, that is cylindrical with an axis D, is designed, as shown in
Preferably, the external diameter of the conductive lateral surface 96 is slightly larger than the internal diameter of the bracelet 60 at the contact portions 70. Simply the insertion of the connector 90 between the lugs 62 therefore already ensures, due to the elasticity of the lugs 62, a minimal contact pressure between the contact portions 70 and the conductive surface 96.
The connector 90 has a crank 98 connecting the second and third cylindrical sections 902 and 903 and provided with substantially axial teeth 100 shaped to interact with the teeth 54 of the ring 50 in order to ensure a rotational coupling between the connector 90 and the ring 50.
As shown in
The connector 90 is usually made of an electrically conductive material.
In order to install the accessory 10 according to the invention, the base 64 of the bracelet 60 is first placed on the edge 24 of the main body 20 in an angular position allowing the subsequent insertion of the tenons 52 of the ring 50 into the housings 25. The ring 50 is then housed in the bottom of the axial groove defined by the bracelet 60, as shown in
The accessory thus installed can be assembled to the connector 90.
Accordingly, the nut 30 is screwed onto the thread 93 of the connector. This screwing provides a radial locking and axial guidance making it easier to insert the lateral conductive surface 96 between the lugs 62 of the bracelet 60. Screwing is continued up to the position shown in
To prevent this elasticity excessively opposing the axial closing of the connector 90 and the main body 20, this pressure must however be limited.
In the position of
When the operator continues screwing the nut 30 onto the connector 90, the base 64 of the bracelet 60 sustains a pinching of increasing amplitude between the ring 50, in axial abutment on the crank 98, and the main body 20 drawn in the direction C of the connector by the nut 30, via the retention ring 40. This pinching of increasing amplitude, shown by the three arrows F in
It now seems clear that, in the event of a lightning discharge, the route of the electric current between the circular connector 90 and the metal lugs 62 and between the metal lugs 62 and the main body 20 of the accessory is via clear electrical contacts, and preferably many of them. The risk of damage is therefore considerably reduced, in particular if the ring 50 is made of an electrically insulating material, at least at the teeth 54.
In addition, the pressure of the lugs 62 on the conductive surface 96 and the pressure between the base 64 of the bracelet 60 and the main body 20 of the accessory 10 may be adjusted to the desired level simply by tightening the locking nut, irrespective of the initial pressure applied by the lugs 62, opposing the insertion of the connector 90 between the lugs 62. This initial pressure may therefore advantageously remain low, or even zero.
After assembly, the axes of assembly D of the main body 20, of the nut 30, of the ring 50, of the bracelet 60 and of the connector 90 are substantially indistinguishable.
a and 4b represent a second embodiment of the invention. Unlike the preceding embodiments, the increase in the contact pressure does not result from a pivoting of the lugs under the effect of a pinching of the base 64 between the ring 50 and the main body 20. In this embodiment, the base 64′, the edge 24′ and the face 56′ may all extend in parallel, in transverse planes. The increase in pressure results from a pressure F′ of a shoulder 102′ of the nut 30′ on a protruding external surface 104′ of the lugs 62′ when the nut is moved axially M on the main body 20.
As shown in
By continuing screwing the nut 30′, the operator brings the shoulder 102′ to push against the surface 104′ of the teeth 62′, as shown in
Naturally the present invention is not limited to the embodiments described and represented, supplied as illustrative and nonlimiting examples.
In particular, the various embodiments could be combined.
Moreover, the moment when the pressure applied by the contact portion is increased is not necessarily after the axial placing in contact of the connector, of the ring, of the bracelet and of the main body. For example, in the second embodiment, the allowed movement of the retention ring 40′ may be limited or even zero. The increase in pressure beyond simply the pressure due to the elasticity of the lugs will then occur at the same time as this axial placing in contact.
Number | Date | Country | Kind |
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0754277 | Apr 2007 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR08/50587 | 4/3/2008 | WO | 00 | 11/10/2009 |