A PART FOR CONNECTING A GAS MICRO-GENERATOR TO

INITIATION MEANS

The present invention relates to a part for connecting a gas micro-generator for a motor vehicle safety device to means for initiating this micro-generator.

In the field of motor vehicle safety, such a gas micro- generator is routinely employed in safety belt pretensioning or retracting devices.

The problem associated with the mounting of such devices lies essentially in the lack of space.

More precisely, such a pretensioner is mounted at the end of a belt loop, and in the vicinity of the chassis of the vehicle. In practice, the operator has very little space to connect the gas micro-generator to the means which, according to information delivered by an impact detector, will cause its initiation. They are usually in the extension of one another.

Such a micro-generator usually comprises two pins or electrodes which transmit an electric current to the charge contained in the generator, thereby causing its initiation. But the connection of these pins is difficult in terms of space requirement, so the pins are sometimes twisted,

This is not acceptable because it may compromise the triggering of the pretensioner system.

The prior art on the matter may be illustrated by document EP-A-1 201 512.

It describes a gas generator that is provided with several initiators,

The technical problem to be solved is their connection to initiation means, while preventing any risk of an incorrect connection .

To do this, various solutions are described. They all have in common the provision of connection means that are differentiated for each initiator. Use is therefore made of foolproofing means which prevent any incorrect connection .

Different parts are fitted onto the pins of the initiators. These parts are extended by electric conductor wires whose terminal portion has the appearance of the male end-piece of an electric plug. Their pins are received in matching initiation parts.

The present invention aims to solve this problem by proposing an intermediate part which allows the connection of a gas micro-generator to its ignition device, doing so without being hampered by the limited space that is available for the installation, without in any way changing the structure and the operation of the parts currently available, and in total safety.

The present invention therefore relates to a connection part for connecting a gas micro-generator for a motor vehicle safety device that has electrically conducting pins connected to an ignition compound, to means for initiating this micro-generator that are also electrically conductive .

According to the invention, this part is noteworthy in that it comprises, at one end, female means for receiving said pins of the micro-generator, electrically connected to pins placed at a second end, in order to connect them electrically to the initiator means, the female means and the pins being placed in respective orientations forming between them an angle lying between 45° and 135° , This angle is

advantageously of the order of 90° and preferably equal to 90° .

Thanks to this part, it is therefore possible to modify the orientation of the micro-generator relative to the connection means, since the latter together form an angle lying between the aforementioned two values, and preferably of the order of 90°, In practice, the operator has much more room at his disposal in this direction.

Furthermore, the part according to the invention in no way modifies the devices that it is intended to connect since, on the one hand, the pins of the micro-generator are adapted thereto, while its own pins are adapted to the ini tiator device which remains unchanged .

Furthermore, according to other advantageous and non- limiting features of this part: - it comprises two branches forming an angle of 90° between them; the pins are identical to and occupy the same disposition as that of the pins of the micro-generator; it comprises a metal casing.

Other features and advantages of the present invention will appear from the following description of a preferred embodiment .

This description will be made with reference to the appended drawings in which:

Figure 1 is a view in section, along a longitudinal mid-plane of a commercially available gas micro-generator; - Figure 2 is a bottom view of a micro-generator, such as that of Figure 1, connected t.o a connection part according to the invention;

Figure 3 is a side view of the assembly of

Figure 2;

Figure 4 is a view similar to Figure 3 of the aforementioned assembly, with partial cutaway in order to show the mutual connection means .

Figure 1 represents a gas micro-generator capable of being used with the connection part according to the invention .

This micro-generator (1) comprises a cylindrical initiator support (2) provided with a central bore (20) leading to the end surface of the support (2) and extended by a hollow cylindrical neck (21) whose axis is indistinguishable from the axis of the support (2) referenced X-X'.

An initiator body (3) in the shape of an axi-symmetric part having a swollen mid-portion enters the hollow neck (21) and the top portion of the bore (20) . This initiator body rests on an O-ring placed at the bottom of the neck (21) and is fixedly attached to the initiator support (2) by swaging the free end of the neck (21) on the enlarged paid-portion of the initiator body (3) .

Two axial pins or electrodes (30) pass through the initiator body (3) over the whole of its height. Their top ends, not visible, lead into the top portion of the body (3) and are connected together by a pyrotechnic ignition assembly comprising in particular a heating resistor and a pyrotechnic ignition compound.

Their bottom ends lead into the bottom portion of the central bore (20) , as is particularly visible in the figure .

In the whole of the present application, the terms "pin" and "electrode" will be used without distinction to designate the same parts.

A cylindrical sheath (5) made of fine fragmentable metal is attached by swaging to the top periphery of the initiator support (2) so as to envelope the neck

(21) and the whole of the initiator. This sheath contains grains of ignition powder (4) .

As shown in Figures 2 to 4, the initiator according to Figure 1 is connected to the part (β) according to the invention. It is a part consisting for example of a metal casing,

As is more particularly visible in Figure 4, this connection part (6) comprises, at one end, the female means (62) for receiving the pins (30) of the micro- generator (1). These means, in the shape of sleeves, are electrically connected to pins (61) placed at a second end of the part for electrically connecting them to initiator means that are not shown here.

According to the invention, the female means (62) and the pins (61) are placed in respective orientations that form between them an angle α of 90° , In embodiments not shown, this angle could be different and lie between 45° and 135°.

In practice, the value of the angle depends on the direction in which the maximum space is available.

In another embodiment, this part could have a bent shape consisting of two branches forming an angle of 90° between them.

In any case, the part (6) forms a rigid unitary assembly, that is to say it is not deformable, its shape being fixed by the respective orientations of the female means and of the pins.

Preferably, the pins (61) that are fitted to the connection part (6) are identical to and occupy the

same disposition as that of the pins (30) of the micro- generator (1) .

Therefore, it is not necessary to modify anything on the micro-generator, likewise on the initiation means that will cause the ignition of the charge of this micro-generator. Therefore, not only is the sleeve- fitting of the parts relative to one another made easier, but the cost of the assembly is not unnecessarily burdened.