EP2362496B1 - Connection element production method for bayonet connector and connection device - Google Patents

Abstract

The method involves forming a through bore (12) by piercing a wall (5) of a body of a bayonet connecting element (1) from an outer surface (10) of the wall. An outer surface of the wall around the through bore is machined so as to form hollow. A lug (4) is inserted into the through bore from the outer surface of the wall such that a head (8) of the lug is projected from the outer surface of the wall of the bayonet connecting element. The formation of the through bore and the machining of the outer surface of the wall are executed in a simultaneous manner. An independent claim is also included for a bayonet connecting element for a connector.

Description

The invention relates to a method for producing a connection element, such as a base, for a bayonet connector. More specifically, the invention relates to the assembly of lugs participating in the bayonet system of the connector on the main body of the corresponding connection element.

It is known to lock the connection between a plug and an electrical connector base, for example, by means of a bayonet system. More specifically, the plug is provided with a locking ring fixed in translation and adapted to be locked on the outer wall of the complementary base when the connection between the contacts of the plug and the contacts of the base is made. The main body of the base is itself provided with lugs projecting radially outwardly from the outer wall of the base. These lugs are intended to cooperate with grooves dug in the inner wall of the locking ring. At the end of locking of the ring around the base, the lugs open into holes formed at the ends of the grooves, in order to make the locking of the plug and the irreversible base, or at the very least to make the unlocking unintentional impossible.

Such a bayonet locking device is of great interest from the point of view of the speed of locking. It is therefore widely used in many fields, such as that of civil or military aeronautics, or any other application in a severe environment.

US 5256077 A discloses a connection element for a bayonet connector according to the preamble of claim 9.

Numerous embodiments of the lugs on the body of the base are known. For example, the lugs can be cut in the mass. They are then made of the same material as the body of the base and have the mechanical characteristics of this material. The lugs being wear parts, when the body is light alloy, the wear resistance is then less than when the body is stainless steel. Otherwise, the lugs can be reported mechanically and, in this case, they can be in a different material, including stainless steel, to meet the wear requirements. Thus, it is known to report stainless steel pins on an aluminum alloy base body. The body of the base must, however, be treated to resist corrosion. Such treatment consists of more often in a protective layer, applied by chemical or electrolytic deposition or electroplating. This protective layer allows such a connector to withstand various environmental hazards and, in particular, to withstand humid environments by eliminating the risk of corrosion or rust.

Standards in connectivity require a visual cue, color at the top of the pins. The user must be able to see the lugs through the holes in the locking ring when locking is achieved. Most often the lugs are reported on the body of the base once the deposition of the anticorrosion protection layer made, so that the body of the base has a uniform color, corresponding to that of the anticorrosive layer, different from those studs reported later. Otherwise, it is also possible to proceed with the anti-corrosion deposit after the establishment of the lugs on the body of the base. In this case, it is necessary later to paint the tops of the lugs of a different color. This second solution is meticulous and expensive.

This is why, in most cases, it is preferable to first proceed with the deposition of the protective layer and then with the placement of the lugs.

Increasingly stringent environmental standards now prohibit the use of certain compounds that are considered harmful to the environment. Thus, Cadmium and Chromes VI have been banned for the realization of such protective layers because of their high toxicity to the environment. It has therefore been necessary to find substituents for the realization of this anticorrosion deposit. However, the compositions currently used for producing the protective layer do not have the same ductility as those rich in cadmium and are therefore much more brittle than these. In current devices, it is therefore common for the mechanical stresses between certain points of contact of the lugs on the base covered with the anticorrosive layer to cause breaks in this protective layer. In addition, the establishment of even the lugs on the base, which requires a force insertion of said lug into the corresponding hole formed on the base, can cause cracks in the protective layer. These cracks and breaks are therefore concentrated in the contact zone between the lug and the orifice on the base, revealing the raw material used to make the base body. The anticorrosion function of the protective layer is therefore not maintained in these areas. The device as a whole is weakened.

Also, in the invention, it is sought to provide a method of producing a connection element for bayonet connector, such as a base, which does not have all or part of the disadvantages mentioned above. Another object of the invention is to provide a connection element for bayonet connector, provided with lugs, and which is able to withstand mechanical stresses especially at the area of connection with the lugs, whatever the nature coating that can cover said connecting element.

For this, the invention proposes to flatten, for example by countersinking, the surface bordering the open end of the orifices provided on the wall of the connecting element and intended to receive the lugs. More specifically, according to the invention, the burrs on the external surface of the connection element, consecutive to the piercing and bordering the corresponding orifice, are removed, or at least driven outwards, so that the surface external of the connection element has a flat surface, without asperities or bosses, at least facing the head of the pin that will come into contact with it. Indeed, when piercing the wall of the body of the connecting element, there is a material reflux forming a ring of material around the open end of the orifice obtained. Now, it is precisely at the level of this burr, concentrated therefore on the outer periphery of the orifice, that the head of the lug housed in the orifice comes to support. As the surface of the pin head is very small, the pressure exerted by the head on the connecting element is concentrated at this irregular surface. The mechanical stresses are therefore very high in this small contact area, when the surface on which these stresses are exerted is not ductile, especially in the case where the connection element is covered with an anticorrosion layer, breaks and cracks may appear. The invention therefore proposes to eliminate, or push back beyond the contact area between the connection element and the lug head, this reflux of raw material. This provides a perfectly flat and smooth surface around the open end of the orifice. The head of the lug then comes into contact with a flat and smooth surface, which makes it possible to limit the mechanical stresses between the lug head and the external surface of the connection element. Moreover, according to the invention, in order to further reduce the potential mechanical stresses at the level of the zone of contact between the head of the lug and the external surface of the connecting element, the wall of the connecting element bordering the orifice may be planed to form a convex rounding and to eliminate any sharp edge between the surface plane bordering the orifice and the orifice proper. The presence of this rounding at the orifice makes it easier to introduce the lug and to avoid having a sharp circular imperfection between the orifice and the bottom of the countersink. Indeed, a sharp angle intersection may have fine machining burrs that weaken the protection covering the part. In addition, even without burr, during the deposition operation of the protective layer, for example by electroplating, the thickness of the deposited layer is difficult to control in this intersection because of the peak effect. The fact of making a rounding, or at least chamfering this intersection, eliminates the risk of over-thickness and thus burrs during the anti-corrosion deposit. This smooths the contact area between the shoulder of the lug, at the junction between the head of the lug and the body of said lug, and the wall of the connecting element.

1. a) on réalise un alésage traversant par perçage de la paroi du corps de l'élément de connexion, depuis la surface externe de ladite paroi ;
2. b) on usine la surface externe de la paroi autour de l'alésage de manière à creuser une surface plane autour dudit alésage ;
3. c) on insère un ergot dans l'alésage, depuis la surface externe de la paroi, de manière à ce qu'une tête de l'ergot soit en saillie de la surface externe de ladite paroi.

The subject of the invention is therefore a method for producing a connection element, such as a bayonet base for a connector, in particular an electrical or optical connector, according to which a connecting element body, of generally cylindrical shape, is produced. hollow, characterized in that it comprises the following additional steps:

1. a) a through bore is made by drilling the wall of the body of the connecting element from the outer surface of said wall;
2. b) the outer surface of the wall is machined around the bore so as to dig a planar surface around said bore;
3. c) inserting a lug in the bore, from the outer surface of the wall, so that a head of the lug protrudes from the outer surface of said wall.

The body of the connection element can be made by molding or machining. It has a cylindrical through hole extending along the longitudinal axis of said body, and opening at both ends of said body. This orifice is intended to receive an insulator also cylindrical in which extend along the longitudinal axis of the contacts of the connection element.

By flat surface is meant a surface that does not have defects or irregularities in surfaces, such as bosses, asperities, etc.

The outer surface of the connecting element is hollowed, so that the flat surface ring is set back from the rest of the outer surface of the connection element,

Advantageously, the operations a) to c) are repeated for each of the lugs to be mounted on the wall of the connection element.

According to the embodiment method of the invention, it is possible to perform steps a) and b) simultaneously, by means of any known tool, notably allowing the simultaneous drilling and counterboring of the wall.

Generally, the lug is inserted into force in the corresponding bore, whose diameter is at best equal to the diameter of the pin, so as to meet the mechanical requirements and functional constraints to allow the lugs to perform their functions.

• on ménage un rayon de raccordement convexe au niveau de la jonction entre la surface plane autour de l'alésage et ledit alésage, sur toute une circonférence dudit alésage avant d'insérer l'ergot dans l'alésage.

In a particular embodiment of the invention, provision may be made to have two, three or more lugs on the outer wall of the connection element. In this case, steps a to c are repeated as many times as there are pins to bring on the wall of the connection element. According to an exemplary implementation of the method according to the invention, it is possible to carry out the following additional step:

• providing a convex connection radius at the junction between the planar surface around the bore and said bore, over a circumference of said bore before inserting the pin into the bore.

By convex connection radius means a junction area between two surfaces, not having a sharp edge. Thus, the convex connection radius may consist of a round, but also a chamfered surface.

In this case, advantageously, the convex connection radius is produced on the wall of the body of the connection element so that it is strictly greater than a concave connection radius at the junction between the head and the body of the lug to be inserted into the corresponding hole.

Preferably, the flat surface formed around the bore has a diameter at least equal to the diameter of the head of the lug to pass through said bore.

1. e) on sertit l'extrémité arrière de l'ergot, monté dans l'alésage correspondant, sur la surface interne de la paroi de l'élément de connexion.

In order to ensure that the pin remains in position on the wall of the connection element, it is possible to perform the following additional step:

1. e) the rear end of the lug, mounted in the corresponding bore, is crimped onto the inner surface of the wall of the connecting element.

The method according to the invention advantageously makes it possible to apply an anti-corrosion protection on the external surface of the wall of the connection element after having made the bore, and before having inserted the pin into said bore, while guaranteeing the integrity of the anticorrosive surface.

Of course, it is also possible to proceed with the deposition of the anticorrosion layer only once the lugs are attached to the wall of the connecting element, in this case, as explained above, it is often necessary to proceed to a subsequent further step of coloring, or other, pins heads,

The invention also relates to a connection element for a bayonet connector comprising a hollow cylindrical main body, intended to receive electrical or optical contacts, a connection portion of the main body, intended to be connected to a complementary connection element, comprising at least one at least one through bore for receiving a lug projecting radially outwardly from the outer surface of the wall of the main body, characterized in that it has a flattened surface ring hollowed from the outer surface of the wall, said flattened surface ring surrounding at least one through bore for receiving a lug, and a convex connecting radius forming a junction between the flat surface ring and the cylindrical portion of the bore.

• l'anneau de surface aplanie présente un diamètre au moins égal au diamètre de la tête de l'ergot que l'alésage correspondant est destiné à recevoir.
• l'élément de connexion comporte au moins un ergot logé dans un alésage ménagé sur la paroi dudit élément de connexion, ledit ergot présentant, au niveau d'une jonction entre la tête et le corps un rayon de raccordement concave strictement inférieur au rayon de raccordement convexe de l'alésage dans lequel il est logé.

According to embodiments of the connection element for bayonet connector according to the invention, it is possible to provide all or part of the following additional characteristics:

• the flattened surface ring has a diameter at least equal to the diameter of the head of the lug that the corresponding bore is intended to receive.
• the connection element comprises at least one lug housed in a bore formed on the wall of said connection element, said lug having, at a junction between the head and the body, a concave connection radius strictly less than the connection radius convex of the bore in which it is housed.

• Figure 1 : une représentation schématique d'un corps d'embase pour connecteur à baïonnette, muni d'ergots ;
• Figure 2 : une représentation schématique d'une embase à baïonnette selon l'invention au niveau d'un alésage muni d'un ergot ;
• Figure 3 : une représentation en coupe transversale de l'embase à baïonnette de la figure 2.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These are presented as an indication and in no way limitative of the invention. The figures represent:

• Figure 1 : a schematic representation of a base body for bayonet connector, provided with lugs;
• Figure 2 : a schematic representation of a bayonet base according to the invention at a bore provided with a lug;
• Figure 3 : a cross-sectional representation of the Bayonet Base of the figure 2 .

On the figure 1 is represented a bayonet connector base 1 provided with three pins 4 (only two visible on the figure 1 ).

The base 1 is provided with a main body 2, a connection end 3 carries the lugs or protuberances 4 of the bayonet system. The lugs 4 extend on an outer perimeter of the main body 2. The lugs protrude outwardly from the outer surface 10 of the wall 5 of said main body 2, in order to cooperate with a locking ring provided with complementary orifices (not shown). The main body 2 of the base 1 is provided with an insert 6 extending longitudinally in the hollow body of the main body 2, said insert 6 being provided with four longitudinal housings 7 in which contacts are intended to extend.

On the figure 2 , there can be seen an enlargement of a protuberance 4 of a base as described in FIG. figure 1 which has been put in place according to the method of the invention.

The figure 3 represents the same enlargement in cross section.

The lug 4 protrudes from the outer surface 10 of the wall 5 of the main body 2 of the base 1. More specifically, the lug 4 passes through the wall 5, so that the body 13 of said lug is less partially accommodated in a through-orifice 12 formed in said wall 5, and in such a way that the head 8 of said lug 4 projects from the outer surface 10 of said wall 5.

A flattened surface ring 11, or flat surface ring, is hollowed from the outer surface 10 of the wall 5 and surrounds the head 8 of the lug 4. The diameter D of the flattened surface ring 11 is strictly greater than the diameter d of the head 8 of the lug 4. The flattened surface ring 11 has a perfectly smooth surface, without roughness, roughness or other surface defects.

The flattened surface ring 11 being hollowed from the outer surface 10 of the wall 5, a part of the head 8 of the lug 4 is set back relative to the outer surface 10 of said wall 5. Advantageously, the height h of the housing formed by the flattened surface ring 11 is small relative to the height H of the lug head 8, so that it can cooperate with the grooves of the locking ring to be mounted around the base 1. The height refers to the dimension extending radially from the wall of the base.

The flattened surface ring 11 can be obtained, in particular by counterboring or machining, simultaneously or subsequently with the drilling of the through orifice 12 formed in the wall 5 of the main body 2 of the base 1 and intended to receive the body 13 of the the lug 4.

The through bore 12 is formed radially in the wall 5 of the main body 2 of the base 1, and thus opens by a first end 15 at the outer surface 10 of said wall 5, and by a second end 18, opposite at the first, at an inner surface 17 of said wall 5. the inner surface 17 borders the cylindrical orifice 9 of the base 1.

The diameter d of the head 8 of the lug 4 is strictly greater than the diameter of the through bore 12, so that the head 8 of the lug 4 rests on the flattened surface ring 11.

More specifically, the shoulder 14 corresponding to the connection between the head 8 and the cylindrical body 13 of the lug 4 rests against the flattened surface ring 11. Insofar as all the impurities and surface irregularities of the outer wall 5 have been driven during the countersink beyond said ring 11, the surface on which the shoulder 14 rests is perfectly flat, thus reducing the mechanical stresses.

Moreover, in order to facilitate the insertion of the cylindrical body 13 of the lug 4 into the corresponding bore 12, a convex connection radius R2 is provided at the intersection between the flat surface of the ring 11, and the first end 15 of the bore 12. This avoids having a sharp intersection between the edge of the bore 12 and the angle of the shoulder 14

This convex connection radius R2 facilitates the introduction of the cylindrical body 13 of the lug 4 which, often, must be mounted in force in the bore 12. The presence of this convex connecting radius R2 also reduces the risks embrittlement of an optionally deposited coating on the outer surface 10 of the wall 5.

Moreover, in a fairly systematic manner, the shoulder 14 of the lug 4, has a concave connection radius R1 at the junction between the lower flat surface 19 of the head 8, intended to rest against the flattened surface ring 11 , and the cylindrical portion 13 of said lug 4, which reduces the mechanical stresses at the level of the contact zone between the head 8 of the lug 4 and the external surface 10 of the wall 5 of the base. 1.

Advantageously, the convex connection radius R2 of the bore 12 is strictly greater than the concave connection radius R1 of the lug 4.

Furthermore, a connection radius R2 equal to 0.05 cm, plus or minus 0.005 cm, is preferably chosen for a lug of dimensions between 0.15 and 0.30 cm, provided always that the convex connection radius R2 is strictly greater than concave connection radius R1. Such a convex connection radius R2, of very low value, makes it possible to retain the largest possible bearing surface at the flattened surface ring 11, for the head 8 of the lug 7.

The outer surface 10 of the wall 5 is covered with a protective coating against corrosion, or the like. The deposition of this coating can be achieved by any known means and in particular by chemical deposition, electrolytic or electroplating. According to the invention, this deposit is advantageously made once the through bores 12 made on the outer wall 5 of the base 1, and before the introduction of the lugs 4 in the corresponding bores 12.

The rear end 16 of the body 13 of the lug 4 protrudes from the inner surface 17 of the wall 5. It is thus possible to crimp the rear end 16 on the inner surface 17 of the wall 5, so as to guarantee the holding in position of the lug 4 even in case of very strong stresses.

Claims (11)

1. A method of achieving a bayonet connection element (1) for a switch, according to which a body (2) of the connection element, of a general hollow cylindrical form is achieved, characterised in that it comprises the following additional steps:

   a) a through drill (12) is achieved by drilling through a wall (5) of the connection element body, from the external surface (10) of the said wall;

   b) the external surface of the wall is machined around the drill in a way which hollows out a flat surface (11) around the said drill;

   c) a stop is inserted into the drill, from the external surface of the wall, in a way that the head (8) of the stop overhangs the external surface of the wall of the connection element.
2. A method of achieving a bayonet connection element according to the claim 1, characterised in that it comprises the following additional step:

   - operations a) to c) are repeated for each of the stops (4) before being mounted on the wall of the connection element.
3. A method of achieving a bayonet connection element according to one of the claims 1 to 2, characterised in that the steps a) and b) are carried out simultaneously.
4. A method of achieving a bayonet connection element according to the one of the claims 1 to 3, characterised in that it comprises the following additional step:

   d) a convex blend radius (R2) at the level of the junction between the flat surface around the drill and the said drill, over the whole circumference of the said drill is prepared, before inserting the stop in the drill.
5. A method of achieving a bayonet connection element according to the claim 4, characterised in that the convex blend radius is prepared on the wall of the connection element body in a way that it is purely higher than a concave blend radius (R1) at the level of the junction between the head of the stop and the body of the stop.
6. A method of achieving a bayonet connection element according to one of the claims 1 to 5, characterised in that at the step (b), the flat surface, hollowed around the drill has a diameter (D) at least equal to the diameter (d) of the head of the stop before passing through the said drill.
7. A method of achieving a bayonet connection element according to one of the claims 1 to 6, characterised in that it comprises the following additional step:

   e) the rear extremity (16) of the stop is fastened, mounted in the corresponding drill, on the internal surface (17) of the wall of the connection element.
8. A method of achieving a bayonet connection element according to one of the claims 1 to 7, characterised in that it comprises the following additional step:

   f) an anticorrosion protection is applied onto the external surface of the wall of the connection element, after having achieved the drill, and before having inserted the stop in the said drill.
9. A connection element (1) for a bayonet switch comprising a main cylindrical hollow body (2), intended to receive contacts, a connection section (3) of the main body, intended to be connected to an additional connection element, comprising at least one through drill (12), intended to receive a stop (4), radial overhanging towards the exterior from the external surface (10) of the wall (5) of the main body, characterised in that it presents

   - a flat surface ring (11), hollowed from the external surface of the wall, the said flat surface ring surrounding at least one through drill, and

   - a convex blend radius (R2) forming a junction between the flat surface ring and the cylindrical part of the drill.
10. A connection element for a bayonet switch, according to the claim 9, characterised in that the flat surface ring presents a diameter (D) at least equal to the diameter (d) of the head (8) of the stop that the corresponding drill is intended to receive.
11. A connection element for a bayonet switch, according to one of the claims 9 to 10, characterised in that it comprises at least one stop (4), put in a through drill (12), prepared on the wall of the said connection element, the said stop presenting, at the level of a junction between the head (8) and the body (13), a concave blend radius (R1), purely lower than the convex blend radius of the drill.

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