Title of Invention

A DEVICE WITH A BODY CARRYING A CONNECTION PIN, WITH IMPROVED SEALING BETWEEN THE PIN AND THE BODY

Abstract The invention concerns a device having an element (1) bearing at least one connection pin (3), said pin comprising a portion covered with a sheath (6) including a circular cylindrical outer surface, the sheath being sealingly fixed to the pin and extending in a housing (20) of the body delimited by a circular cylindrical wall (26), a sealing joint (30) being arranged between the sheath outer surface and the housing wall. The invention also concerns a method for making such a device.
Full Text

A DEVICE WITH A BODY CARRYING A CONNECTION PIN, WITH IMPROVED SEALING BETWEEN THE PIN AND THE BODY
The invention relates to any device, e.g. a connector, an electronic unit, and more generally any apparatus, that comprises a body carrying one or more connection pins, and in which sealing of the connection between the pin and the body is critical.
BACKGROUND OF THE INVENTION
Gas injectors are known, for example, that comprise a diaphragm actuated by an electromagnet that is powered electrically via connection pins that project from the body of the injector.
The injector body is generally molded or injection molded and covers a portion of the pin so as to form an interface between the body and the pin. The interface is not completely leaktight, and the gas under pressure present within the injector can escape to the outside via said interface.
Proposals have been made to place a sealing gasket between the body and the pin, however such a disposition can be applied in practice only to pins that are circular in section.
OBJECT OF THE INVENTION
An object of the invention is to improve sealing between pins and the body carrying such pins, including when the pins are of section that is not circular.
BRIEF SUMMARY OF THE INVENTION
The invention provides a device having a body carrying at least one connection pin, in which the pin has a portion covered in a sheath having a circularly cylindrical outside surface, the sheath being fastened in leaktight manner to the pin and extending in a housing of the body that is defined by a circularly cylindrical

wall, a sealing gasket being disposed between the outside
surface of the sheath and the wall defining the housing.
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Thus, by interposing an additional part between the pin and the body, one interface is replaced by two interfaces:
a first interface between the pin and the sheath,
which is made leaktight by sealed bonding means, e.g. of
the adhesive type or of the solder type; and
a second interface between the sheath and the body, that is made leaktight by a sealing gasket extending between two circularly cylindrical walls.
These two interfaces are made leaktight by processes that provide better performance than mere contact between the body and the pin of the kind that results from injecting the body around the pin, and as a result the leaktightness of the device is improved.
The invention also provides a method of fabricating such a device, the method comprising the steps of:
• engaging a sheath on the pin and stopping the sheath longitudinally relative to the pin; and
• securing the sheath to the pin by causing a liquid bonding substance to infiltrate by capillarity between the pin and the sheath.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be better understood in the light of the following description given with reference to the figures of the accompanying drawings, in which:
• Figure 1 is a side view of a gas injector cover in accordance with the invention, as shown partially in section on line I-I of Figure 2 through one of its pins;
• Figure 2 is a face view of the Figure 1 injector cover;
• Figure 3 is a fragmentary view showing a portion of Figure 1 on a larger scale in the vicinity of the sheath;

• Figure 4 is a plan view of a pin and a sheath during the step of securing the sheath on the pin; and
• Figure 5 is an enlarged view in section on line V-V of Figure 4.
DETAILED DESCRIPTION OF THE INVENTION
With reference to Figure 1, the gas injector cover in accordance with the invention comprises a body 1 having a bottom portion adapted to be mounted on the injector proper (not shown herein). The body 1 of the cover contains an electromagnet (not shown) serving to actuate a moving element of the injector, e.g. a diaphragm.
The body 1 includes a portion that is shaped to form a connector 2 having metal connection pins 3 extending therein (only one pin being shown) for feeding electricity to the electromagnet.
Each of the pins 3 includes a free portion 4 projecting from the body 1, followed by a connection portion 5 connecting it to a metal sheath 6 and extending in line with the free portion 4.
The sheath 6 is engaged on the pin 3 and is bonded thereto via the connection portion 5 by means of a solder alloy that extends so as to completely fill the space between the sheath 6 and the pin 3, thus sealing the connection between the sheath 6 and the pin 3.
To make this connection, and as can be seen in Figure 4, the pin 3 is placed in a j ig (not shown) that holds the pin 3 so that its free portion 4 extends vertically. The sheath 6 is then engaged on the pin 3. In this example, the pin 3 has an arcuate extension 8 and the sheath 6 comes into abutment thereagainst, such that the sheath 6 is naturally brought to rest in register with the connection portion 5 of the pin 3,
A ring of solder alloy 11 is engaged on the pin 3 so as to rest against the end of the sheath 6. The solder alloy ring 11 is heated (e.g. by means of a coil powered

at high frequency and placed around the free portion of the pin) such that the solder alloy melts and infiltrates by capillarity between the pin 3 and the sheath 6. In this respect, a chamfer 12 formed on the sheath 6 facilitates infiltration of the liquid solder alloy between the pin 3 and the sheath 6.
Solidification of the solder alloy seals the connection between the pin 3 and the sheath 6.
According to a particular aspect of the invention, the sheath 6 is left free radially relative to the pin 3 during the bonding step, such that the sheath 6 takes up a position radially relative to the pin solely under the effect of surface tension in the molten solder alloy.
In this respect, and as can be seen particularly clearly in Figure 5, for a pin of rectangular section, the sheath 6 has an inside wall 9 that is rectangular and that extends parallel to the facing outside surface 10 of the pin 3. Under the effect of surface tension, the solder alloy then forms a joint between the sheath 6 and the pin 3 that presents constant thickness and that guarantees that the sheath 6 is centered on the pin 3 and conducts heat uniformly between the pin 3 and the sheath 6.
The pin 3 provided in this way with its sheath 6 is then placed in a mold and the body 1 is injected around the pin 3. In this context, care is taken to ensure that the material used for the body has an injection temperature that is lower than the melting temperature of the solder alloy so as to avoid the sheath being released from the pin while the body 1 is being injected. By way of example, if the body is made of aluminum, it is possible to use an alloy of tin and silver for soldering the sheath on the pin.
As can be seen particularly clearly in Figure 3, the body 1 defines a circularly symmetrical housing 2 0 in which the sheath 6 extends. The housing 20 has a first circular portion 21 that is open to the outside, and then

after a conical transition 22 it has a second circular portion of smaller diameter that is defined by a circularly cylindrical wall 26 extending in register with the circularly cylindrical outside surface 13 of the sheath 6.
The housing 20 extends beyond the end of the sheath 6 and has an end wall from which there extends a central projection 24 that clamps against an outside surface portion 13 of the sheath 6, thus making the connection between the pin 3 and the body 1 more rigid.
The projection 24 defines a shoulder 25 on the outside surface 13 of the sheath 6, which shoulder is preferably conical and forms a seat for a gasket 30 in the form of an 0-ring disposed between the outside surface 13 of the sheath 6 and the facing wall 26 of the housing 20. The 0-ring 30 thus provides sealing between the sheath 6 and the body 1-
The portion of the housing 20 that is immediately adjacent to the shoulder 25 and that extends between the wall 26 and the central projection 24 forms a cavity 27 that is closed by the 0-ring 30 and in which a certain quantity of air is held captive when the 0-ring 30 is put into place. In practice, care is taken to ensure that the cavity 27 has a volume that is large enough to ensure that putting the 0-ring 30 into place leads to only a small increase in the pressure of the air held captive in the cavity 27, such that the increase in pressure cannot prevent the 0-ring 30 from being pushed as far as the shoulder 25.
In order to prevent the 0-ring 30 from being expelled under the effect of the pressure of the gas infiltrating along the outside surface of the pin 30 into the cavity 27, an anti-extrusion ring 31 is placed beside the 0-ring 30 remote from the seat 25, the anti-extrusion ring 31 itself being retained by a spring washer with tabs 32 (particularly visible in Figure 2), which washer is engaged in the first portion 21 of the housing 20 and

is then forced against the conical transition 22 of the housing 20 so that the tips of the pedals become wedged against the outside surface 13 of the sheath 6.
The invention is not limited to the above description, but on the contrary covers any variant coming within the ambit defined by the claims.
In particular, although the invention is described in an application to a pin of non-circular section, the invention applies equally to a pin of circular section, the sheath making it possible to use an 0-ring of larger dimensions than a ring matching the diameter of the pin, and thus a ring that is, a priori, easier to put into place.
Although the sheath is shown during its assembly with the pin as being held in register with the connection portion of the pin by a particular shape of the pin, external stop means could be provided.
Although it is stated that the sheath and the pin are bonded together by adding a solder alloy, the sheath and the pin could be bonded together by other means, such as a liquid adhesive. It is also possible to use other leaktight fastener means, for example welding without any filler material.
Although it is stated that the sheath is made out of metal, the sheath could be made out of any other material, for example it could be made of plastics material.
Although it is stated that the inside wall of the sheath is parallel to the outside surface of the pin, provision could be made for the sheath to have an inside wall of arbitrary shape.
Although the body is shown as clamping against a portion of the outside surface of the sheath, thus achieving greater stiffness in the connection between the pin and the body, the body need not clamp against the sheath. Under such circumstances, the sheath could be provided on the body so as to extend over the wall 26

that defines the housing. The seat could also be formed on the outside surface of the sheath..
Although the sheath is shown as extending in an open housing of the body, the sheath could extend in a housing that is closed. The sealing ring would then need to be put into place from inside the body.




CLAIMS
1. A device having a body (1) carrying at least one
connection pin (3), the device being characterized in
that the pin has a portion (5) covered in a sheath (6)
having a circularly cylindrical outside surface (13), the
sheath being fastened in leaktight manner to the pin and
extending in a housing (20) of the body that is defined
by a circularly cylindrical wall (26), a sealing gasket
(30) being disposed between the outside surface (13) of the sheath and the wall (26) defining the housing.
2. A device according to claim 1, characterized in that the body extends to cover the outside surface (13) of the sheath (6) in part and to form a shoulder (25) on said outside surface.
3. A device according to claim 2, characterized in that the body (1) defines a cavity (27) adjacent to the shoulder (25) and closed by the sealing gasket (30).
4. A device according to claim 1, characterized in that a ring (31) is placed against a flank of the sealing gasket (30), the ring being stopped by a retaining member (32) anchored in the sheath (6).
5. A method of fabricating a device having a body (1) that carries at least one connection pin (3), the method being characterized in that it comprises the steps of:

• engaging a sheath (6) on the pin and stopping the sheath longitudinally relative to the pin; and
• securing the sheath to the pin by causing a liquid bonding substance to infiltrate by capillarity between the pin and the sheath.
6. A method according to claim 5, characterized in that
the step of securing the sheath to the pin comprises the
operations of:

• engaging a ring of solid solder alloy (11) on the
pin so that the ring comes to rest against the sheath;
and
• causing the solder alloy ring to melt so that the
solder alloy infiltrates between the sheath and the pin.
7. A method according to claim 5, characterized in that the sheath (6) has an inside wall (9) parallel to a facing outside surface (10) of the pin (3), the sheath being left free radially relative to the pin during the bonding step. ■
8. A method according to claim 5, characterized in that the pin fitted in this way with its sheath is then integrated in the body (1) of the device.
9. A method according to claim 8, characterized in that
the body (1) of the device is injected around the pin (3)
provided with its sheath (6), the body being injected
using a material that has an injection temperature that
is lower than a melting temperature of the bonding
substance.
10. A method according to claim 8, characterized in that
a sealing gasket (30) is placed between an outside
surface (13) of the sheath and a facing wall (26) of a
housing in the body (1) in which the sheath extends.


Documents:

2303-CHENP-2007 AMENDED CLAIMS 02-09-2011.pdf

2303-CHENP-2007 FORM-3 02-09-2011.pdf

2303-CHENP-2007 POWER OF ATTORNEY 02-09-2011.pdf

2303-CHENP-2007 CORRESPONDENCE OTHERS 02-09-2011.pdf

2303-CHENP-2007 CORRESPONDENCE OTHERS 07-10-2010.pdf

2303-chenp-2007-abstract.pdf

2303-chenp-2007-claims.pdf

2303-chenp-2007-correspondnece-others.pdf

2303-chenp-2007-description(complete).pdf

2303-chenp-2007-drawings.pdf

2303-chenp-2007-form 1.pdf

2303-chenp-2007-form 3.pdf

2303-chenp-2007-form 5.pdf

2303-chenp-2007-others.pdf

2303-chenp-2007-pct.pdf


Patent Number 249067
Indian Patent Application Number 2303/CHENP/2007
PG Journal Number 39/2011
Publication Date 30-Sep-2011
Grant Date 28-Sep-2011
Date of Filing 29-May-2007
Name of Patentee VALEO SYSTEMES DE CONTROLE MOTEUR
Applicant Address 18 CHAUSSEE JULES CESAR, 95520 OSNY
Inventors:
# Inventor's Name Inventor's Address
1 CHARBONNIER, JEAN-PHILIPPE 3 BIS RUE HENRI QUILLET, 95420 CLERY EN VEXIN
PCT International Classification Number H01R13/52
PCT International Application Number PCT/FR05/02908
PCT International Filing date 2005-11-23
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 0412664 2004-11-30 France