EP2840661B1

EP2840661B1 - Snap-fit junction device

Info

Publication number: EP2840661B1
Application number: EP13382335.1A
Authority: EP
Inventors: Jorge Ballestero Méndez; Eugenio Piñeyroa De La Fuente
Original assignee: Airbus Operations SL
Current assignee: Airbus Operations SL
Priority date: 2013-08-20
Filing date: 2013-08-20
Publication date: 2018-02-14
Anticipated expiration: 2033-08-20
Also published as: EP2840661A1

Description

FIELD OF THE INVENTION

The invention provides two interrelated products for a snap-fit junction for an electrical connection provided in the form of a male and a female device. The male and the female devices may be embodied as terminals or sockets suitable for ground and bonding connections in an airplane.

BACKGROUND OF THE INVENTION

The solutions of the prior art used as junction for electrical bonding and grounding comprises one metallic flat or angled support riveted or bolted to the aircraft structure, the conductive part, and to which a bonding braid terminal is usually connected by means of one bolt, one nut and two washers. Then, contact zones are protected from corrosion with an over-coating sealant coating both sides.
This mechanical connection is time consuming and requires some skills of the user to keep the washers, the bolt and the nut correctly positioned when threading the bolt into the nut. This solution presents relatively high assembly times. The assembler must install the standards with the need of a tooling; and it presents high cost of the standards and high weight values since the metallic support and the bonding braid terminal is sized to hold the bolt or rivet rather than to meet the electrical continuity requirements.
In turn, document US 2009/291600 A1 discloses a female terminal for receiving a male terminal, comprising a tubular box part having a receiving portion, a spring piece which includes a fixed end provided inside the box part, and a free end pinching the male terminal between the spring piece and the box part by an elastic reaction force of the spring piece.
The present quick snap-fit junction device is aimed to solve the above identified problems of the prior art in 3 ways:

Reduce the recurrent cost associated to the assembly times thanks to a quick "snap-fit" junction concept, where the assembler just will need to plug and unplug the electrical junction with no need of any tooling.
Reduce the weight of the assembly "support-standards-terminal" by optimizing the design to safely meet the electrical and lightning strike protection requirements.
Reduce the recurrent cost associated to the raw materials and/or standards cost (i.e. bolts, nuts and washers).

SUMMARY OF THE INVENTION

The invention solves the identified problems by providing a first inter-related product and a second inter-related product for a snap-fit junction for an electrical connection provided in the form of a female and a complementary male device according to claim 6 having a particular structure.
The first inter-related product is provided in the form of a female device according to claim 1 and comprises:

an structural case comprising an open planar cavity extended between two opposite internal resting surfaces, a first resting surface and a second resting surface, laterally closed by walls wherein the two resting surfaces and the lateral walls are parallel to an axial direction X-X',
a locking strip resting against the first resting surface,
a electrical conductor strip resting against the second resting surface and separated from the locking strip wherein said electrical conductor strip extends at least in both lateral walls of the structural case by a fold.

If the male device is allowed having any clearance then it may move within the female cavity. If this is the case, hard parts of the male device may harm the internal surfaces of the female device increasing the clearance or it even may deteriorate the structural properties of the case.
According to the invention, the planar configuration of the cavity is adapted to receive the male device and provides means to keep the male device fixed within the open cavity of the female device showing a backlash-free connection ensuring the electrical continuity.
The two main opposite surfaces limit the movement of the male device within the open cavity of the female device along the perpendicular direction to the main plane of such planar configuration. The two lateral walls are adapted to avoid the displacement and rotation within the main plain in such a way the male device is only allowed to move along the axial direction X-X'.
The structural case may be manufactured using polymeric materials which are very cheap. This polymeric component may be damaged by hard materials such as the conductor main body, the planar conductor element of the male device.
The present invention solves the problem by interposing two strips, a locking strip and a electrical conductor strip. Both strips are interposed between the male device and the two opposite internal resting surfaces of the structural case so that the hard parts of the male device do not harm the surface of the cavity of the structural case.
The lateral walls are also protected by the two folds of the electrical conductor strip which is extended at least in both lateral walls of the structural case.

Additionally,

the structural case is adapted to receive the male device in the form of a male electrical conductor by insertion in the axial direction X-X' and housing said male device between the locking strip and the electrical conductor strip and between the both folds of the electrical conductor strip; and,
the locking strip comprises locking means adapted to lock in the axial direction X-X' the male device housed in the structural case.

Once the male device is inserted within the open cavity of the female device the axial displacement is also limited mainly by the locking means. In a preferred embodiment the axial displacement of the male device is limited by the end of the cavity or by elements located at the end of the cavity in one direction of displacement; and, by the locking means in the opposite direction.
At least the electrical conductor strip is in electrical communication with the male electrical conductor ensuring the electrical continuity between the male and the female device.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics and advantages of the invention will be more clearly highlighted from the following detailed description of preferred realization forms, given only as illustrative, not limitative examples, referred to the annexed figures.

Figure 1: Represents a first embodiment of the structural case according to a perspective view having an electrical connection.
Figure 2: Represents a second embodiment of the structural case according to a perspective view.
Figure 3: Represents a perspective view of the locking strip.
Figure 4A-4B: Represent a perspective view of the electrical conductor strip according to the first and the second embodiments respectively.
Figure 5: Represents a perspective view of a plurality of male devices, according to the second embodiment, configured as a prolongation of a common plate adapted to be connected to the ground.
Figure 6A: Represents a plan view and a sectional view along a plane parallel to the axial direction X-X' that allows to see the internal shape of the female device configured as a socket and the male device configured as a terminal according to the first embodiment.
Figure 6B: Represents a plan view and a sectional view along a plane parallel to the axial direction X-X' that allows to see the internal shape of the female device configured as a socket and the male device configured as a terminal according to the second embodiment.
Figure 7A, 7B: Represent a perspective view of the male device before and after the insertion into the female device in the first embodiment.
Figure 8A, 8B: Represent a perspective view of the male device without and with an elastomeric seal ring.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention will now be described with reference to the attached figures, in which the same reference numerals are used to denote the same or corresponding part throughout the several figures.
Figure 1 shows the structural case (1) of a first embodiment of the invention wherein the main body has a cavity(1.1) adapted to receive the male device. In this embodiment the structural case (1) is shaped as a parallelepiped wherein the open cavity (1.1) shows a planar configuration mainly extended along a main plane. The open cavity (1.1) is limited between two opposite internal resting surfaces, a first resting surface (1.1.1) located in the upper part according to figure 1 and a second resting surface (1.1.2) located in the lower part of the cavity (1.1) according to figure 1, laterally closed by walls (1.1.3) wherein the two resting surfaces (1.1.1, 1.1.2) and the lateral walls (1.1.3) are parallel to an axial direction X-X'.
The axial direction X-X' is the direction of the male device when it is inserted into the cavity (1.1) of the female device.
Figure 1 shows the main body of the structural case (1) of the first embodiment having a prolongation (1.2) adapted to cover an electrical connection (3.2) that will be disclosed below.
Figure 2 shows the structural case (1) of a second embodiment of the invention without said prolongation (1.2) and adapted to be configured as a terminal when the remaining pieces are incorporated.
Figure 3 shows an embodiment of a locking strip (2) which is located in the upper part of the cavity (1.1) partially integrated with the first resting surface (1.1.1). The partial integration of the locking strip (2) in the cavity (1.1) of the case (1) is the result of the injection process when manufacturing the case (1). This locking strip (2) comprises:

a fold (2.1) located at one end that is integral with the body of the structural case (1) at the end of the cavity (1.1),
a flange (2.2) located at the opposite end, configured by two consecutive folds, which is prolonged by two tabs (2.3). Both tabs (2.3) are inclined and located outside the cavity (1.1) of the structural case (1) to facilitate the entry of the male device.

The male device is shown in figures 5, 7A, 8A and 8B. In an embodiment, the male device comprises a planar electrical conductor (4), preferably metallic, adapted to be inserted in the axial direction X-X' into the cavity (1.1) of the female device. This planar electrical conductor (4) is configured as limited between a first planar contacting surface (4.1) and a parallel second planar contacting surface (4.2) laterally limited by two guiding walls (4.3).
The planar electrical conductor (4) comprises at least one recess (4.4), in this embodiment two recesses (4.4), adapted to abut on the flange (2.2) of the locking means for the axial retention.
The planar electrical conductor (4) is inserted into the cavity (1.1) because the inclined tabs (2.3) facilitate the insertion causing the deformation of the locking strip (2). When the planar electrical conductor (4) reaches the end of the cavity (1.1), the deformation of the flange (2.2) of the locking strip (2) of the female device is elastically recovered in such a way that it is located abutting the two recesses (4.4) of the planar electrical conductor (4).
The flange (2.2) of the locking strip (2) prevents the exit of the planar electrical conductor (4) of the male device unless the user pushes the tabs (2.3) causing the deformation that allows the recesses (4.4) surpassing the flange (2.2) again; and therefore, the exit of the planar electrical conductor (4) of the male device.
In this embodiment the pulling forces of the flange (2.2) abutting the recesses (4.4) of the male device are compensated by the fold (2.1) of the locking strip (2) integral with the structural case (1); and, additionally the pulling forces are also compensated by a recess (2.4) located in the locking strip (2) between the two tabs (2.3) that houses a further protrusion (1.1.1.1) of the first resting surface (1.1.1) of the structural case (1).
Figures 4A and 4B according to the first embodiment and the second embodiment respectively show the electrical conductor strip (3) configured as three plates, a first plate adapted to rest on the second resting surface (1.1.2) and two lateral folds (3.1) adapted to rest on the lateral walls (1.1.3) of the cavity (1.1) of the structural case (1).
In these two embodiments, the first (1.1.1) and the second (1.1.2) resting surfaces and the lateral walls (1.1.3) of the structural case (1) are covered, and also protected, by the locking strip (2) and the electrical conductor strip (3) surrounding the walls of the cavity (1.1) parallel to the axial direction X-X'.
The electrical conductor strip (3) shown in figure 4A is embodied as a socket and the electrical conductor strip (3) shown in figure 4B is embodied as a terminal with a connection (3.5) adapted to be attached to an electrical wire having electrical continuity.
When the male device is inserted into the female device, the first planar contacting surface (4.1) of the planar electrical conductor (4) is adapted to be in contact with the locking strip (2) of the female device; and, the second planar contacting surface (4.2) is adapted to be in electrical contact with the electrical conductor strip (3) of the female device.
The two guiding walls (4.3) of the planar electrical conductor (4) are adapted to be in electrical contact with both folds (3.1) of the electrical conductor strip (3) of the female device. The electrical contact is improved by means of lateral bumps (4.3.1) that increases the pressure between both contact surfaces and reduces the lateral looseness.
The first planar contacting surface (4.1), the second planar contacting surface (4.2), or both, comprises one or more bumps (4.1.1), preferably two or more, for ensuring the pressure and electrical continuity between the second planar contacting surface (4.2) of the male device and the electrical conductor strip (3) of the female device.
In a further embodiment, the planar electrical conductor (4) comprises one or more grooves (4.5) as shown in figure 8A for housing an elastomeric seal ring (4.6) for avoiding vibrations in the coupling between the male device and the female device and ensuring corrosion protection of the internal parts of the device. When the male device is configured as a terminal, a cylindrical connection (4.7) is used for receiving the electrical wire.
At it is shown in figure 4A, in this first embodiment the electrical conductor strip (3) is prolonged by and electrical connection (3.2) having a hole (3.3) for fixing the electrical connection (3.2) to an structural component being the ground connection. In this first embodiment, the structural case (1) shown in figure 1 also has a prolongation (1.2) covering the electrical connection (3.2) for protecting said electrical connection (3.2).
As it is shown in figure 6A according to the first embodiment, the electrical conductor strip (3) has a double fold (3.4) shifting the plane of the plate resting on the second resting surface (1.1.2) of the cavity (1.1) of the structural case (1) to the location of the plate of the electrical connection (3.2) located under the protecting prolongation (1.2) of said structural case (1).
The sectional view shown in figure 6A also allows to see the bumps (4.1) of the planar electrical conductor (4) pressing the lower surface of the locking strip (2) so that the lower surface of the same planar electrical conductor (4) is also pressing the electrical conductor strip (3) ensuring the electrical continuity.
As it is shown in figure 6B according to the second embodiment, the electrical conductor strip (3) is embodied as a terminal with a connection (3.5) adapted to be attached to an electrical wire and the male device is configured as a plate adapted to be fixed having electrical continuity to an structural component being the ground connection.
Both devices, the male device and the female device, may be configured as sockets or terminals. When it is extended by an electrical wire it is configured as terminal and, if it is fixed to a receiving structure it is defined as a socket. In both cases, a plurality of devices may be configured as a prolongation of a common bounding strap adapted to be fixed to the structure of the airplaine. If the device is the male device, then the common bounding strap is extended in a plurality of prolongations having at the end the planar electrical conductor (4) as shown in figure 5. If the device is the female device, then the common bounding strap is extended in a plurality of prolongations having at the end the electrical conductor strip (3), for instance, integral with said prolongations.

Claims

A female snap-fit junction device for an electrical connection adapted to receive a male device wherein an insertion direction of said male device is an axial direction X-X' comprising:
- a structural case (1) adapted to receive the male device in the form of a male electrical conductor (4) by insertion comprises an open planar cavity (1.1) extended between two opposite internal resting surfaces, a first resting surface (1.1.1) and a second resting surface (1.1.2), laterally closed by walls (1.1.3) wherein the two resting surfaces (1.1.1, 1.1.2) and the lateral walls (1.1.3) are parallel to the axial direction X-X',

- a locking strip (2) resting against the first resting surface (1.1.1),

- an electrically conductive strip (3) separated from the locking strip (2) and configured as three plates, a first plate resting against the second resting surface (1.1.2) and two lateral folds (3.1) resting on the lateral walls (1.1.3) of said cavity (1.1),
wherein
- the structural case (1) is adapted to house the male device between the locking strip (2) and the electrically conductive strip (3) and between the both folds (3.1) of the electrically conductive strip (3); and,

- the locking strip (2) comprises a fold (2.1) located at one end and a flange (2.2) prolonged by at least a tab (2.3) located at an opposite end adapted to lock in the axial direction X-X' the male device housed in the open planar cavity (1.1) of the structural case (1),
and wherein
the locking strip (2) comprises two separated tabs (2.3) extending the flange (2.2) separated by a recess (2.4);
and the structural case has a protrusion (1.1.1.1) on the first resting surface (1.1.1), said protrusion (1.1.1.1) being housed in the recess (2.4) of the locking strip (2) for the axial retention of said locking strip (2); and wherein
the male device is configured to be locked in the axial direction X-X' by means of said fold (2.1) at an end of the open planar cavity (1.1) and by the flange (2.2) in an opposite end.
A female snap-fit junction device according to claim 1, wherein the locking strip (2) and the electrically conductive strip (3) are metallic.
A socket embodied as a female snap-fit junction device according to any preceding claim, wherein the electrically conductive strip (3) comprises an electrical connection (3.2) adapted to be electrically connected to a ground frame.
A socket according to claim 3 wherein the structural case (1) comprises a prolongation (1.2) for covering, at least partially, the electrical connection (3.2) of the electrically conductive strip (3) adapted to be electrically connected to a ground frame.
A terminal embodied as a female snap-fit junction device according to any of claims 1 to 2, wherein the electrically conductive strip (3) comprises an electrical connection (3.5) adapted to be electrically connected to an electrical line.
A male snap-fit junction device for an electrical connection configured as a metallic electrical conductor (4) adapted to be inserted in an axial direction X-X' in a female device according to any of claims 1 to 2 is configured as limited between a first planar contacting surface (4.1) and a parallel second planar contacting surface (4.2) laterally limited by two guiding walls (4.3)
wherein
- the first planar contacting surface (4.1) is adapted to be in contact with a locking strip (2) of the female device,

- the second planar contacting surface (4.2) is adapted to be in electrical contact with an electrically conductive strip (3) of the female device,

- the two guiding walls (4.3) are adapted to be in electrical contact with two folds (3.1) of the electrically conductive strip (3) of the female device,

- the planar electrical conductor (4) comprises at least one recess (4.4) adapted to abut on a flange (2.2) of the locking strip (2) for the axial retention in the axial direction X-X';
and wherein
- the first planar contacting surface (4.1), the second planar contacting surface (4.2), or both, comprise one or more bumps (4.1.1), for ensuring the pressure and electrical continuity between the second planar contacting surface (4.2) of the male device and the electrically conductive strip (3) of the female device.
A male snap-fit junction device according to claim 6 wherein the first planar contacting surface (4.1) comprises two bumps (4.1.1) aligned along the axial direction X-X'.
A male snap-fit junction device according to claim 6 wherein the planar electrical conductor (4) has a groove (4.5) for housing a peripheral elastomeric seal ring (6) for sealing the open cavity of the female device.
A terminal embodied as a male snap-fit junction device according to any of claims 6 to 8 wherein planar electrical conductor (4) comprises an electrical connection (4.7) adapted to be electrically connected to an electrical line.
A socket embodied as a male snap-fit junction device according to any of claims 6 to 8, wherein the planar electrical conductor (4) is the prolongation of a common plate providing an electrical connection adapted to be electrically connected to a ground frame.
An electrical snap-fit junction device comprising a combination of a at least a first female snap-fit junction device according to any of claims 1 to 2 and at least a second male snap-fit junction device according to any of claims 6 to 8.