Societe Nationale Des Poudres Et Explosifs

Bernard J Doin

Jean-Francois Tillac

Bernard E Plantif

Michel C Pasquier

Robert Omer Grebert

Jean S Beaumont

Yves Pierre Jouhaud

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 process for the rapid production of a substantial volume of non-toxic gas at a moderate temperature, comprises: A. effecting combustion of a pyrotechnic charge consisting of a composite solid propellant having a high content of inorganic oxidant, in excess of 80 percent and a low content of a carbonaceous, non-nitrogenous binder, not in excess of 17 percent in a combustion chamber to produce a substantial volume of combustion gases at an elevated temperature B. a first cooling phase in which the hot combustion gases are diluted with oxygen obtained by the thermal decomposition of an oxygen-containing inorganic compound which has a low thermal stability and liberates, in gaseous form, only oxygen, whereby the combustion gases are cooled to a temperature of from 225.degree. to 700.degree.C, and C. a second cooling phase in which the gas mixture from the first cooling phase is cooled by contact with cooling means to the temperature of utilization. The gas mixture so produced is used, for example, for the inflation of flexible enclosures and for the deployment of inflatable safety devices, such as in automobiles.

Production of non-toxic gas by combustion of solid propellant

One or both ends of the body of a solid fuel rocket engine is provided with an internally thickened portion, which serves for the mechanical attachment of additional parts, that is the rocket head or the rocket base, to the end of the engine body, without any increase in the external cross-sectional dimension of the body. A block of propellant fuel is located within the engine body and has a portion of reduced cross-sectional dimensions corresponding to the internally thickened portion at the end of the engine body. The block is introduced into the body by cooling the former until its dimensions have shrunk sufficiently for it to be introduced.

Growing community of inventors

Saint Medard en Jalles, France

Bernard J Doin