EP1057228B1 - Electrical connector contact pin - Google Patents

Description

The present invention relates to a contact pin of an electrical connector.

Multi-pin electrical connectors usually have a large number of contact pins that include a connection end intended for cooperate with the connecting end of a contact pin of a connector associated multi-pin and a connecting end for receiving a driver of electric cable welded, brazed or wound on said end.

It is known to realize these contact pins in two parts, namely a front part constituting the connection end and a rear part constituting the end connection, so that different materials with different properties can be used elasticity and plasticity are adapted.

In such contact pins, a problem arises for the connection front and rear parts, knowing that this connection must be made in a simple way and fast and must provide a good electrical contact by introducing the minimum of disturbances in the electrical signal transmitted by the spindle.

The present invention aims to provide a new contact pin made of two parts that constitutes an original solution to the problem above.

Also known from GB-A-2,274,749 or US-A-4,780,097 a spindle of contact of an electrical connector comprising a body, a connection element and a sleeve, the connection element being held in the extension of the body by coupling with a pin protruding from the front face of the body, the sleeve being disposed around the connection element and held on the body by clamping a portion ring of the latter.

The present invention relates to a contact pin of this type, characterized in that the connecting element comprises, on the pion side, a end of coupling with the pin, shaped in such a way that the piece can not not register within the cross-section of said coupling end, the connecting element being able to deform elastically to allow its end of coupling to engage on the pin, said connection element and deformed that can not fit within the cross-section of the sleeve, and the fact that the sleeve and the pin are separated by a clearance greater than the thickness of the wall of the coupling end of the connection element.

In other words, in the contact pin according to the invention, the element of connection is trapped between the integral pawn of the body and the sleeve in conditions such that said connecting element is elastically constrained by the pin and by the sleeve.

The sleeve is also firmly secured to the body by a force fit on an annular portion of the body, it follows that the connection mechanical connection between the connection element and the rest of the contact pin is particularly reliable.

It is understood that since the connection element has not been in place between the pin and the sleeve, that elastic deformations, the forces that on the one hand, between the connection element and the sleeve and on the other hand, between the connecting element and the pin are due to the elastic return of the connection element.

In other words, the connection element undergoes no deformation plastic which would reduce the forces that it exerts by elastic return on the sleeve and on the pawn.

Another essential advantage of the contact pin according to the invention is to allow relatively wide manufacturing tolerances, since the elasticity of the connection element makes it possible to catch up to a large extent the defects of dimensioning between parts.

D_{Text. max} ≤ D_Smin

D_Smin - D_Pmax ≥ 2.e_max

D_Tint.max < D_Pmin

D_Pmin - D_Tint.max > D_Smax - D_Text.min

   où

• D_Text.max est le diamètre extérieur maximum de l'élément de connexion, compte tenu de ses tolérances de fabrication,
• D_Text.min est le diamètre extérieur minimum de l'élément de connexion, compte tenu de ses tolérances de fabrication,
• D_Tint.max est le diamètre intérieur maximum de l'élément de connexion, compte tenu de ses tolérances de fabrication,
• e_max est l'épaisseur maximale de l'élément de connexion, compte tenu de ses tolérances de fabrication,
• D_Smin est le diamètre intérieur minimum du manchon, compte tenu de ses. tolérances de fabrication,
• D_Smax est le diamètre intérieur maximum du manchon, compte tenu de ses tolérances de fabrication,
• D_Pmax est le diamètre extérieur maximum du pion, compte tenu de ses tolérances de fabrication,
• D_Pmin est le diamètre extérieur minimum du pion, compte tenu de ses tolérances de fabrication.

Thus, taking into account the manufacturing tolerances of the body of the connection element and the sleeve, the contact pin, according to a preferred embodiment of the invention, can be defined as verifying the following conditions:

D _{Text. max} ≤ D _Smin

D _Smin - D _Pmax ≥ 2.e _max

D _Tint.max <D _Pmin

D _Pmin - _Tint.max D> D _{S max} - D _Text.min

or

• D _Text.max is the maximum outside diameter of the connection element, given its manufacturing tolerances,
• D _Text.min is the minimum outside diameter of the connection element, given its manufacturing tolerances,
• D _Tint.max is the maximum inside diameter of the connection element, given its manufacturing tolerances,
• e _max is the maximum thickness of the connection element, given its manufacturing tolerances,
• D _Smin is the minimum inside diameter of the sleeve, given its. manufacturing tolerances,
• D _Smax is the maximum inside diameter of the sleeve, given its manufacturing tolerances,
• D _Pmax is the maximum outside diameter of the pin, given its manufacturing tolerances,
• D _Pmin is the minimum outside diameter of the pin, given its manufacturing tolerances.

It goes without saying that the ability to compensate for manufacturing tolerances automatically, by the arrangement of the contact pin according to the invention, allows to manufacture the various parts that constitute it by implementing processes of simple and inexpensive manufacturing, while retaining good electrical qualities at the brooch.

In a particular embodiment of the invention, the connection element is dimensioned to be able to slide freely in the sleeve before having undergone the deformation resulting from the fitting of its coupling end on the pin.

In a preferred embodiment, the connection element has a longitudinal slot that allows it to move from a closed position in which both edges of said slot touch to an open position in which the two edges of said slot are spaced from each other, this open position resulting from the deformation said connecting element.

Preferably, the connection element is in its closed position before to have undergone the deformation resulting from the fitting of its coupling end on the pawn.

Thus, after placing the sleeve, the connection element finds a position close to its closed position, the two edges of its slot being almost contiguous. this which has the consequence that the connection element, once in place in the spindle of contact, can maintain a stable shape, even after a significant number of connections / disconnections, since only its interface part itself is deforms elastically.

In general, as is the case with most known contact pins, the body, the connecting element and the sleeve of the spindle according to the invention are parts substantially of revolution.

In a particular embodiment, the coupling end of the connecting element has a circular cross section of inner diameter less than the inside diameter of the circular cross section of the rest of the element of connection.

The present invention also relates to a method of mounting a contact pin as described above.

Such a method is characterized by the fact that it consists in inserting the end coupling of the connection element to the pin of the body of the pin, then to present the sleeve in alignment with the deformed connecting member, the sleeve being kept in a sheath whose inner dimensions match substantially to the outer dimensions of the sleeve, to engage the retained sleeve in the sleeve around the connecting element in a translation movement until the sleeve has completely covered the connection element, then to move the sleeve into the sheath while keeping it still to bring said sleeve by axial translation on the annular portion of the body, before removing the scabbard.

This process has the essential advantage that it comprises only operations axial translation, which facilitates its automation.

• la figure 1 est une vue en coupe longitudinale d'une broche de contact selon l'invention,
• la figure 2 est une vue rapprochée en coupe longitudinale de l'élément de connexion de la broche de la figure 1,
• la figure 3 est une vue de gauche de la figure 2,
• la figure 4 est une vue de dessus de la figure 2,
• les figures 5 et 6 sont des vues en perspective de l'élément de connexion de la figure 2,
• les figures 7A, 7B, 7C et 7 D sont des vues en coupe partielle de la broche de contact pendant son montage, et
• les figures 8A, 8B et 8C sont des vues en coupe selon VIII-VIII des figures 7A, 7B et 7C.

In order to better understand the invention, will now be described an embodiment given by way of non-limiting example with reference to the accompanying drawing in which:

• FIG. 1 is a view in longitudinal section of a contact pin according to the invention,
• FIG. 2 is a close-up longitudinal sectional view of the connection element of the pin of FIG. 1,
• FIG. 3 is a left view of FIG. 2,
• FIG. 4 is a view from above of FIG. 2,
• FIGS. 5 and 6 are perspective views of the connection element of FIG. 2,
• FIGS. 7A, 7B, 7C and 7D are partial sectional views of the contact pin during its assembly, and
• Figures 8A, 8B and 8C are sectional views along VIII-VIII of Figures 7A, 7B and 7C.

The contact pin 1 shown in FIG. 1 comprises a body 2, a connecting element 3 and a sleeve 4.

The body is extended to the left by a branch end (no represented) which may have different forms for connection to a cable conductor. It can be a crimp barrel, a wrapping exit (or winding) the driver, or a pin output for a printed circuit board.

In contrast to its branch end, the body 2 has a flange 5 of large diameter which borders an annular portion 6 of smaller diameter provided to ensure the retention of the sleeve 4.

Projecting from the front face 7 of the body, which delimits the annular portion (6) with the collar 5, a pin 8 of circular section and of diameter D _P less than that of the annular portion 6 is provided to receive the element of connection.

The body 2 is made of brass which is an inexpensive material.

The connection element 3, which is better visible in FIGS. 2 to 6, is is substantially in the form of a tube having a longitudinal slot 9.

In its closed position shown in Figures 2 to 6, 7A and 8A, that is to say in its position in which the two edges 10 of its longitudinal slot 9 are touching, the connection element 3 has an outer diameter D _Text slightly less than the inside diameter D _s of the sleeve, so that the connection element can, in its closed position, slide freely in the sleeve.

At its front end, that is to say to the right with respect to the figures, the element connection 3 has four slots 11 which separate four elastic fingers 12 folded in the direction of the axis of the connection element, intended to constitute a female interface connecting with a corresponding male contact pin (not shown).

In contrast to this connection interface, the connection element 3 comprises a coupling end 13 with the pin 8 of the body.

This coupling end 13 has a circular cross-section of inner diameter (D _Tint ) less than the inside diameter of the circular cross-section of the rest of the body.

The shape of this coupling end 13 is better visible on the FIGS. 2 to 4 show a cutout 14 made in the wall of the element of connection, leaves on the rear face 15 a ring portion of which both ends 16 are deformed towards the inside of the connection element.

The wall of the connection element has the same thickness over its entire length, including at its coupling end 13.

As can be seen in FIGS. 3 and 8A, the coupling end thus formed in the closed position of the connection element for a cylindrical volume which is materialized by a circle represented in lines interrupted, which is inscribed inside the cross section of the end coupling.

This circle has a diameter D _Tint less than that D _P of the pin 8 projecting from the front face of the body.

Therefore, this pawn 8 can not fit inside the section cross-section of the coupling end when the connection element is closed position.

We will now describe the assembly of the pin according to the invention in reference to Figures 7A-7D and 8A-8C.

As can be seen in FIGS. 7B and 8B, the fitting on the pin 8 of the coupling end 13 of the connection element 3 causes a deformation of the latter, which then takes an open position in which the two edges facing each other 10 of its slot 9 are distant from each other.

In this open position, the connecting element 3 undergoes an increase in its external diameter, of a value equal to the difference D _p - D _Tint between the diameter of the pin 8 and that of the circle inscribed inside the section. crosswise of the coupling end 13.

In other words, after fitting of the coupling end 13 to the pin 8, the outer diameter of the coupling element is equal to D _Text + D _p -D _Tint

The dimensions of the pin, the coupling element and the sleeve are chosen so that the diameter of the connecting element deformed by fitting on the pin is greater than the internal diameter D _s of the sleeve.

As a result, if the sleeve 4 is presented in alignment with the element of connection 3 and that it slides axially around this connection element 3 using of a sleeve 17 which holds it firmly, notably preventing it from being deformed radially, it causes the tightening of the connection element to a position adjacent to its closed position in which the edges opposite 10 of its longitudinal slot 9 are very close to each other, as seen in Figures 7C and 8C.

In this position, the radial clearance D _s - D _p existing between the pin and the inner wall of the sleeve is occupied by the coupling end of the connecting element, elastically constrained between said sleeve and said pin.

In order to avoid any creep of the pin, the connection element or the sleeve, so that the engagement of the sleeve around the connection element only results in a purely elastic deformation of the element of connection, the dimensions of the different components of the contact pin have been determined in such a way that the radial clearance (D _s -D _p ) / 2 existing between the pin and the inner wall of the sleeve is greater than the thickness e of the wall of the connection element.

Thus, the connection element undergoes only elastic deformations and by elastic reaction exerts a radial pressure on the pin and the sleeve.

Once the connection element is completely covered by the sleeve, stops the progression of the sleeve 17 and we continue to move the sleeve 4 axially by pushing it towards the body 2 with the aid of a pusher 18, which causes the radial expansion of the sleeve which engages force on the annular portion 6 of the body, until it comes to a stop against the flange 5.

The sleeve is thus firmly secured to the body.

The connection element, which has only undergone elastic deformation, is also firmly attached to the rest of the contact pin, on the one hand of its elastic contact with the sleeve, on the other hand, because of its elastic contact with the pawn.

It is understood that the elasticity of the connection element can easily be used to compensate for the manufacturing tolerances of the body, the pin of which has a diameter between D _Pmin and D _Pmax of the sleeve, the internal diameter of which may vary from D _min to D _smax and the connection element, whose outer diameter can range from D _Text.min to D _Tex.max , and whose coupling end may leave room for a cylindrical volume of diameter between D _{Tint .min} and D _Tint.max .

Claims (8)

1. Contact pin of an electrical connector comprising a body (2), a connection element (3) and a sleeve (4), the connection element being held in the extension of the body by coupling with a stud (8) projecting from the front face of the body, the sleeve being arranged around the connection element and held on the body by clamping on an annular portion (6) of the latter, characterised in that the connection element (3) comprises on the stud side an end (13) for coupling with the stud, shaped so that stud (8) cannot fit inside the transverse section of the said coupling end, where the connection element (3) can deform elastically to allow its coupling end (13) to slide over the stud (8), said connection element thus deformed not being able to fit inside the transverse section of the sleeve (4) and therefore that the sleeve (4) and the stud (8) are separated by a play (D_s-D_p)/2 greater than the thickness (e) of the wall of the coupling end of the connection element (3).
2. Contact pin according to claim 1, characterised in that before deformation, the connection element (3) can slide freely in the sleeve (4).
3. Contact pin according to any of claims 1 and 2, characterised in that the connection element (3) has a longitudinal slot (9) which allows it to change from a closed position in which the two edges (10) of said slot touch to an open position in which the two edges (10) of said slot are separated from each other, this open position resulting from the deformation of the said connection element.
4. Contact pin according to claim 3, characterised in that before deformation the connection element (3) is in its closed position.
5. Contact pin according to any of claims 1 to 4, characterised in that the body (2), the connection element (3) and the sleeve (4) are approximately generated by rotation.
6. Contact pin according to claim 5, characterised in that the coupling end (13) has a circular cross-section of internal diameter (D_Tint) less than the internal diameter of the circular cross-section of the remainder of the connection element.
7. Contact pin according to any of claims 1 to 6, characterised in that the body (2), the connection element (3) and the sleeve (4) fulfil the following conditions:

   D_Text.max ≤ D_Smin

   D_Smin - D_Pmax ≤ 2.e_max

   D_Tintmax < D_Pmin

   D_Pmin - D_Tint.max > D_Smax - D_Text.min

   where

   D_Text.max is the maximum external diameter of the connection element taking into account production tolerances,

   D_Text.min is the minimum external diameter of the connection element taking into account production tolerances,

   D_Tint.max is the maximum internal diameter of the connection element taking into account production tolerances,

   e_max is the maximum thickness of the connection element taking into account production tolerances,

   D_Smin is the minimum internal diameter of the sleeve taking into account production tolerances,

   D_Smax is the maximum internal diameter of the sleeve taking into account production tolerances,

   D_Pmax is the maximum external diameter of the stud taking into account production tolerances,

   D_Pmin is the minimum external diameter of the stud taking into account production tolerances.
8. Process for assembling a contact pin according to any of claims 1 to 7, characterised in that it comprises pushing the coupling end (13) of the connection element (3) onto the stud (8) of the pin body (2), then presenting the sleeve (4) in the alignment of the deformed connection element (3), the sleeve (4) being held in a sheath (17) of internal dimensions approximately corresponding to the external dimensions of the sleeve, engaging the sleeve (4) held in the sheath (17) around the connection element (3) following an axial translation movement until the sleeve (4) has fully covered the connection element (3), then moving the sleeve (4) in the sheath (17) and holding the latter immobile in order to bring the said sleeve (4) by axial translation onto the annular portion (6) of the body (2) before withdrawing the sheath (17).

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