Electro-pyrotechnic unlocking device, in particular for a safety fixture for a ski

Abstract

The device is automatically re-armed and comprises at least one pyrotechnic jack and a push-member actuated by the jack for unlocking the fixture. A loader carries a plurality of pyrotechnic charges for actuating the jack in succession. A device is provided for igniting the charges and a device is provided for positioning the charges of the loader with respect to the push-member and with respect to the device for igniting the charges.The present invention relates to an automatically re-armed electro-pyrotechnic unlocking device and more particularly, although not exclusively, to such a device applied to a safety fixture or binding for a ski.Safety fixtures are known which are opened by a pyrotechnic charge which is ignited by means responsive to critical exterior influences when said influences appear or act.An object of the invention is to provide an unlocking device of the aforementioned type which is relatively simple in construction and easy to use.According to the invention, there is provided an automatically re-armed and reloaded electro-pyrotechnic unlocking device in particular for a safety ski binding, comprising at least one gas operated mechanical assembly for unlocking said binding, a loader, a plurality of pyrotechnic charges for actuating said assembly in succession and carried by the loader, means for igniting the charges, and means for automatically positioning the charges of the loader with respect to said assembly and with respect to said means for igniting the charges.

Description

Claims

1. An automatically re-armed and reloaded electro-pyrotechnic unlocking device in particular for a safety ski binding, comprising a body, at least one gas operated mechanical assembly for unlocking said binding, a loader movably mounted relative to said body, a plurality of pyrotechnic charges for actuating said assembly in succession and carried by the loader, means for igniting the charges, and means for automatically positioning the charges of the loader with respect to said assembly and with respect to said means for igniting the charges, wherein said mechanical assembly comprises a piston and cylinder unit associated with one of the charges carried by the loader and provided with a push-member which when actuated by the gas releases the binding.

2. A device as claimed in claim 1, wherein said mechanical assembly comprises a cylinder, a piston slidably mounted in the cylinder and carrying a push-member, the cylinder having an inner end portion, an orifice provided in said inner end portion for connection of the cylinder with one of said charges carried by said loader.

3. A device as claimed in claim 1, comprising a shaft parallel to the direction of displacement of the push-member and constituted by a plug pin which is detachably mounted in the body of the device, and means for holding the plug pin stationary in translation.

4. A device as claimed in claim 1, wherein said at least one gas operated mechanical assembly comprises as many piston and cylinder units as there are charges carried by said loader and a push-member, said units being also carried by the loader, in registration with the corresponding charges, each unit being located in a position intermediate between said push-member and the corresponding charge.

5. A device as claimed in claim 1, wherein each of said units comprises a finger member for actuating said push-member, said finger member being slidably mounted in a corresponding bore and provided at an end of the finger member in the vicinity of the charge with a flange, the bore having a shoulder at an end of the bore opposed to the charge and acting as an abutment, and a return spring surrounding the finger member and disposed between said flange and the abutment.

6. A device as claimed in claim 1, wherein said means for positioning the charges with respect to said mechanical assembly and to said charge igniting means comprise recesses having an inclined face and an innermost end face and formed in a face of said loader which faces said assembly, said recesses being in a number which is equal to the number of charges and so disposed that said innermost end face of each recess is capable of facing the centre of a charge, a rod connected to said assembly and co-operating with said recesses, a number of cams equal to the number of charges and formed in a lateral face of the loader, at least one pawl for shifting the loader by cooperation with and application against said cams, and elastically yieldable means for biasing said pawl against each one of said cams in succession.

7. A device as claimed in claim 6, wherein the displacement of said loader under the action of said pawl occurs in the course of the unlocking operation, upon the retraction of the positioning rod out of the recess that it previously occupied, whereas the displacement of the loader under the action of the cooperation of the rod with the ramp of the innermost end face of the recess which follows occurs upon the operation of the re-arming of the device.

8. A device as claimed in claim 1, wherein said loader is of rectilinear shape and movable in translation with respect to said push-member and to said charge igniting means by said positioning means of the loader.

9. A device as claimed in claim 8, wherein bores are formed in said loader and said charges are constituted by cartridges disposed in the bores, each cartridge comprising an outer case at one of which outer case there is mounted a stud of an electrically conductive material, and an electrically ignitable primer composition within the outer case and in contact with the stud, said outer case being constructed from an electrically conductive material at least to a region of the primer composition, a propelling or deflagrating powder charge mounted adjacent an opposite end of the case to said stud the case having an orifice for the passage of the gases actuating the push-rod, a thin disc closing the orifice, the propelling powder charge being retained within the case by said disc which closes said orifice, the primer composition being capable of igniting the propelling powder charge.

10. A device as claimed in claim 9, wherein the common case of the powder charges is constituted by the loader made from an electrically conductive material at least to the region of the primer composition.

11. A device as claimed in claim 9, wherein said charges comprise an outer case at one end of which outer case there is mounted a stud of an electrically conductive material, a primer composition ignited electrically and in contact with said stud, said case being made from an electrically conductive material at least to the region of the primer composition, a propelling or deflagrating powder charge, said primer composition being capable of igniting the propelling powder charge, a piston slidably mounted in said case and having a rod adapted to actuate the unlocking system for the binding, said propelling powder charge being capable of actuating the piston.

12. A device as claimed in claim 11, wherein the loader comprises a part made from an electrically conductive material and a part made from an insulating material.

13. A device as claimed in claim 11, wherein the loader is made wholly from an insulating material, tubular elements of an electrically conductive material being disposed in corresponding bores of the loader.

14. A device as claimed in claim 1, wherein said piston defines with the cylinder two chambers, the cylinder being provided with an aperture for putting said chambers in succession in communication with the atmosphere upon a displacement of said piston under the effect of gases produced by said charge connected to the cylinder by way of said orifice.

15. A device as claimed in claim 14, wherein each of said units comprises a first disc which is movable in said bore when the force exerted by the pressure of the gases produced by the charge exceeds a predetermined threshold value and a second fixed disc constituting an inner end of the cylinder of said unit, the charge being confined in a sealed manner between said discs.

16. A device as claimed in claim 15, wherein each cam has a portion of decreasing section and a portion of increasing section the extent of the portion of decreasing section of each cam extending the extent of the corresponding recess and defining with the corresponding recess the travel of the loader between two successive charges.

17. A device as claimed in claim 15, comprising, incorporated in each one of said charges, a piston and cylinder unit for actuating said push-member, the charge and the unit being disposed in a common case.

18. A device as claimed in claim 15, wherein the lateral face of said loader further comprises an abutment which is encountered at the end of the utilization of the loader.

19. A device as claimed in claim 18, wherein said barrel includes recesses cooperating with a rod integral with said push-member said recesses being curved and disposed around said charges in such a manner that the deepest end of each recess is located on a radius of the barrel passing through the centre of a charge.

20. A device as claimed in claim 19, wherein said means for positioning the loader with respect to said push-member and to said igniting means comprise cam surfaces formed in lateral faces of the loader perpendicular to a face of the loader in which there are formed bores receiving said charges, the number of said cam surfaces formed in each of said lateral faces of the loader being equal to the number of charges of said loader.

21. A device as claimed in claim 19 wherein said rectilinear movable in translation loader contains a row of charges fixedly mounted therein and adapted to be automatically aligned in succession with said push-member for unlocking or releasing the binding.

22. A device as claimed in claim 21, comprising a cranked lever pivotally mounted in the body of the device, and a biconical portion of said push-member, the cam surfaces formed in one of the lateral faces of said loader being constituted by notches cooperative with an end of said lever, said lever having adjacent an end thereof opposed to said end cooperative with said notches a cranked portion perpendicular to the rest of said lever and cooperative with the biconical portion of said push-member.

23. A device as claimed in claim 21, wherein a positioning rod is connected to said push-member and the cam surfaces formed in one of the lateral faces of said loader cooperate with the positioning rod and are constituted by rectilinear recesses formed at regular intervals in said loader, each recess having an inner end a portion of which inner end is in the form of a ramp and another portion of which inner end is of maximum depth, whereas the cam surfaces formed in another lateral face of the loader are each constituted by a decreasing portion and an increasing portion of equal length, a spring-loaded pawl being cooperative with said cam surfaces formed in said other lateral face of the loader for shifting the loader.

24. A device as claimed in claim 23, wherein said end of the cranked lever cooperative with the notches is constituted by an elastically yieldable blade;

25. A device as claimed in claim 23, wherein said notches have a side adapted to receive the force exerted by said end of the cranked lever cooperative with the notches for shifting the loader in translation.

26. A device as claimed in claim 23, wherein the cam surfaces formed in said other lateral face of said loader each comprise a decreasing portion, a portion of constant depth, and an increasing portion and a spring-loaded pawl is cooperative with said cam surfaces for shifting the loader in translation, the relative positions of said cams and corresponding notches being such that said pawl is depressed in the course of the displacement of said loader under the effect of the pivoting of said lever upon the displacement of the unlocking push-member.

27. A safety binding in combination with an automatically re-armed and reloaded electro-pyrotechnic unlocking device, comprising a body, at least one gas operated mechanical assembly for unlocking said binding, a loader movably mounted relative to said body, a plurality of pyrotechnic charges for actuating said assembly in succession and carried by the loader, means for igniting the charges, and means for automatically positioning the charges of the loader with respect to said assembly and with respect to said means for igniting the charges, wherein said mechanical assembly comprises a piston and cylinder unit associated with one of the charges corried by the loader and provided with a push-member which when actuated by the gas releases the binding.