Societe Nationale Des Poudres Et Explosifs

Jean-Francois Tillac

Bernard J Doin

Bernard E Plantif

Michel C Pasquier

Alain Soulignac

Jean-Pierre Hoguet

A dismountable mechanical core (1) includes a counterform (2) attached to a central mandrel (3,8), the counterform components being able to be handled remotely and with complete safety. These components of the counterform are connected and attached to the central mandrel (3,8) by rod anchoring devices (6). The process of assembly and disassembly of the core is also described. This dismountable mechanical core is used for the molding of the cavity inside the charge of solid rocket fuel.

Dismountable mechanical core and procedure for implementing it

Traction device for a displaceable component such as a seat belt used for protecting people in a vehicle. The traction device according to the invention comprises drive means which comprises at least one flexible tube which is rolled up and can be expanded under the action of a pressurized fluid, and, preferably, the pressurizing component is a pyrotechnic gas generator. Application to the production of a dynamic unit for protection by means of a safety belt which can be actuated by a collision detector is described.

Traction device for safety belts

A device for causing the rotation of a movable element which is connected to a displaceable component such as a safety belt used for protecting people in a vehicle is described. The rotary device includes drive means which comprises at least one flexible tube which is rolled up and can be expanded under the action of a pressurized fluid, and, preferably, the pressurizing component is a pyrotechnic gas generator placed inside the flexible tube which is rolled up in a helix or a spiral. The device may be used for protection of an individual in a moving vehicle by means of a safety belt. The device can be actuated by a collision detector.

Device for causing rotation, having a pressurized tubular drive means

The device for winding up an elongate flexible element, such as a vehicle safety belt of U.S. Pat. No. 3,970,266 comprises a casing, an axle mounted in the casing and rotationally fast therewith, a hollow winding-drum rotatably mounted in the casing coaxial with and surrounding the axle, an annular piston positioned between the drum and axle and axially movable relative thereto between initial and final positions, an annular pressure chamber defined within the drum by piston, a pyrotechnic charge for pressurizing the pressure chamber with combustion gases therefrom to propel the piston axially along said drum and axle from the initial position to the final position, first cooperable guide means on the piston and the drum, and second cooperable guide means on the piston and the axle and is improved by providing an annular piston which is formed by two annular half-pistons, one of the half-pistons cooperates through the first guide means with the drum, the other of the half-pistons cooperating through the second guide means with the shaft, and the half-pistons have means for interconnecting the half-pistons to move together. The interconnecting means is constituted by substantially radial teeth formed on the opposed faces of the half-pistons. A restraining mechanism is interposed between the drum and the shaft for opposing rotation of the drum relative to the shaft.

Winding device particularly useful in connection with vehicle safety

A pyrotechnic gas generator for inflating safety cushions in vehicles, including a device for regulating the operating pressure and/or limiting the maximum gas pressure in the generator, comprises a combustion chamber defined in a cup-shaped member having its open end releasably held against a casing part and movable away from the casing part, by the gas pressure in the combustion chamber, to open up an injection orifice of variable through flow area which connects the combustion chamber with a cooling chamber containing solid coolant.

Pyrotechnic gas generator having a movable combustion chamber

A device for winding up a vehicle seat belt in the event of a vehicle impact comprises a hollow winding drum rotatably mounted in a casing coaxially surrounding a threaded central axle which is rotationally fast with the casing. An annular piston inserted between the drum and axle is axially movable by the pressure generated by combustion gases issuing from a pyrotechnic charge detonated by a signal from an impact detector, to rotate the drum and wind up the belt, the piston being keyed for rotation with the drum and for helical movement relative to the axle. Under normal conditions the drum is free to rotate to wind up and unwind the belt, but a mechanism is automatically actuated upon impact to prevent or oppose rotation of the drum in an unwinding direction.

Device for winding a seat belt in vehicles

A gas generator for generating a large volume of gases at moderate temperature in an extremely short time comprises a central combustion chamber containing a solid pyrotechnic charge and an ignition device therefor. The combustion chamber is laterally surrounded by a cooling chamber with which it communicates by means of apertures. In the cooling chamber combustion gases formed on ignition of the pyrotechnic charge are cooled by contact with at least one solid coolant material. The cooled combustion gases are discharged from the generator through apertures in the side wall of the generator which are disposed symmetrically with respect to the axis of the generator, so that when the combustion gases leave the generator they exert substantially no propulsive force on the generator.

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Bordeaux Cauderan, France

Jean-Francois Tillac