Abstract:
The safety lock comprises a control member which prevents an untimely actuation of the jettisoning device by inserting a locking member on the path of a movable release member of this device. Simultaneously the safety lock releases braking members in order to allow nuts to rotate for ensuring the raising of the hooks to which the load is suspended.

Description:
BACKGROUND OF THE INVENTION 
     Several carrying and jettisoning devices for loads under aircraft are already known, as well as methods for wedging these loads against fixed bearings by raising the hooks of the carrying device after the loads has been suspended thereto. 
     Generally, immediately after the load is hooked, a safety pin is introducted into the carrying device to prevent any untimely releasing thereof. Complementary operations can thus be performed without risk, particularly the actuation of nuts ensuring the raising of the suspension hooks for bringing the load to engage fixed bearing members. Such screw and nut systems are theoretically irreversible but, since in flight they are subject to relatively high vibrations particularly aboard helicopters, they have to be immobilized by braking means after their screwing. 
     SUMMARY OF THE INVENTION 
     In order to make easier the successive operations which consist in introducing the safety pin into the carrying device, in braking the nuts after screwing thereof and in removing the safety pin, and to prevent an omission, it is proposed according to the invention to combine these operations in a single device only necessitating one action of the operator on an operating handle. 
     In a removed position of this handle (corresponding to a flight position of the device), the nuts are locked and the release mechanism is free. Since the nuts are locked, the operator cannot perform the wedging of the load and to this end he must necessarily first move the handle to a raised position that results in locking the release mechanism and releasing the nuts. Inversely, before taking off, the operator has to move back the handle to its remove position thus causing the release mechanism to be freed and the hook raising nuts to be locked. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic longitudinal section of the device, with the load being hooked, the suspension hooks being in their lowermost position and the nuts adjusting the height of the hooks being released; 
     FIG. 2 is a sectional transverse view of the suspension hooks in their lowermost position; 
     FIG. 3 is a view similar to FIG. 1, with the device being in its flight condition i.e. the suspension hooks being in their uppermost position, the load engaging the fixed bearings, the nuts adjusting the upward position of the hooks being locked, and the safety lock being removed; 
     FIG. 4 is a sectional transverse view of the device with the suspension hooks in their uppermost positions; and 
     FIG. 5 is plan view from above of the device showing the mechanism ensuring the release of the nut brakes. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the drawings the reference numeral 1 designates diagrammatically the contour of the hooking device of the aircraft, 2 being the load, 3 and 3&#39; being the supporting hooks engaging the rings 4 and 4&#39; respectively of the load 2, 5 and 5&#39; being straps to which the hooks 3 and 3&#39; are respectively pivoted, these straps comprising tail portions 6 and 6&#39; respectively which are urged downwards by springs 7 and 7&#39; respectively. The tail portions 6 and 6&#39; are moved vertically by nuts 8 and 8&#39; which present radial bores such as 9 and 9&#39; into which can be introduced a working pin and a castellated circular portion 10 and 10&#39;. 
     The supporting hooks 3 and 3&#39; are pivoted about pins 11 and 11&#39; to the straps 5 and 5&#39; respectively, and they are connected to an effort demultiplication mechanism which is of a well known type and consequently which has not been described in detail. This effort demultiplication mechanism essentially comprises links 12 and 12&#39; which are pivoted to a member 13 adapted to rock on fixed bearings 14. The rotation of the rocking member 13 is prevented by means of a hook member 15 pivoted on fixed bearings 16. A rotation of the hook member 15 in the direction of the arrow of FIGS. 1 and 3 liberates the rocking member 13 and thus allows the opening of the supporting hooks 3 and 3&#39;. The hook member 15 is urged by a compression spring 17 towards its position preventing rotation of the rocking member 13. The rotation of the hook member 15 to liberate the rocking member 13 is obtained through the action of a small piston 18 actuated in turn by a pyrotechnic impeller 19 simultaneously actuating the ejection piston 20. 
     Reference numeral 21 designates (see particularly FIG. 2) a lock adapted to rotate about a vertical axis on bearings 22 and 23. At its lower part lock 21 presents a heel portion 24 adapted to enter under a part 25 of hook member 15, and the upper part of said lock 21 presents a cam shaped plate 26 adapted simultaneously to actuate rods 27 and 27&#39;. The rods 27 and 27&#39; are each urged by a spring 28 and 28&#39; respectively towards the castellated portions 10 and 10&#39; of nuts 8 and 8&#39;. These rods 27 and 27&#39; are guided in bearings 29-30 and 29&#39;-30&#39; respectively and each one carries a strap 31 and 31&#39; acting as a bearing for the associated springs 28-28&#39; while, at its end adjacent the nut 8 and 8&#39; to be braked, each rod 27 and 27&#39; carries a wedge-shaped nose portion 32 and 32&#39; adapted to engage notches of castellated portions 10 and 10&#39;. At its opposite end each rod 27 and 27&#39; carries a finger 33 and 33&#39; engaging a cam member 34 and 34&#39; of plate 26. The reference numeral 35 designates an operating handle 35 for the rotating lock 21 (see FIG. 5) which is urged in a removed position by means of a spring fastener 36 when the device is in position ready for flight. 
     The mode of operation of the device is as follows, assuming the supporting hooks are in their lowermost position and the load 2 is suspended through its rings 4 and 4&#39; as shown at FIG. 1. By rotating the operating handle 35 from its flight position shown in full lines in FIG. 5 to its removed position shown in chain dotted lines, the lock 21 is caused to rotate in the direction of the arrow of FIG. 5 and to enter its heel portion 24 under portion 25 of the hook member 15 (see FIGS. 1 and 2) thus preventing a releasing of the load hooking mechanism, even in the event of an untimely operation of pyrotechnic impeller 19. 
     Simultaneously the rotation of plate 26 rigid with lock 21 causes, due to the shape of cam members 34 and 34&#39; (see FIG. 5), the retirement of the nose portions 32 and 32&#39; of rods 27 and 27&#39; from the notches of the castellated portions 10 and 10&#39;. Thus a rotation of nuts 8 and 8&#39; by means of a standard pin (not shown) introduced into the bores 9 and 9&#39; is made possible and allows the raising of load 2 and the wedging thereof against the fixed bearing members 37 and 37&#39; as indicated in FIG. 4. 
     A reverse operation of handle 35 frees the heel portion 24 and liberates the release mechanism, while the springs 28 and 28&#39; cause the nose portions 32 and 32&#39; of rods 27 and 27&#39; to engage the castellated portions 10 and 10&#39; of nuts 8 and 8&#39;, as shown at FIG. 3 which is similar to FIG. 1 but differs therefrom on the one hand by the fact that supporting hooks 3 and 3&#39; have been raised to bring the load in the position of FIG. 4 and, on the other hand, by the freeing of the locking heel 24 liberating the release mechanism and by the simultaneous engagement by the castellated portions 10 and 10&#39; of nuts 8 and 8&#39; by the nose portions 32 and 32&#39; of the rods 27 and 27&#39;. 
     Although a specific form of embodiment of this invention has been described hereinabove and illustrated in the accompanying drawings, it will readily occur to those skilled in the art that various modifications and changes may be brought thereto without departing from the scope of the invention as set forth in the appended claims.