Abstract:
A device for winding up a safety belt is locked in response to a change of inertia of the device housing. The device includes two elements at least one of which is a rotatable member having a pulley at one end with a band wound around it. An end of the band extends from the pulley and is connected to the safety belt. One end of the rotatable member is arranged adjacent the other element in the housing. A locking member is moved by its own inertia in response to an inertial change in the device housing and is engaged between the two elements to lock rotation of the rotatable member.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a winding up or take up device for a safety belt. 
     SUMMARY OF THE INVENTION 
     This device is characterized by the fact that it comprises a wedge-shaped movable member which is moved by its inertia, and is engaged between two elements of the device. At least one of the elements is constituted by a rotatable member rigidly connected with a drum on which is wound a flexible band so that, when the wedge shaped member engages between the elements, it locks the one rotation of the elements which is constituted by the rotatable member. 
    
    
     BRIEF DESRIPTION OF THE INVENTION 
     The drawing shows, by way of example, one embodiment of the invention and several modifications. 
     FIG. 1 is a sectional view of a winding up device for a safety belt. 
     FIG. 2 is a sectional view of a detail of a modification. 
     FIGS. 3 and 4 are perspective views of a detail of two other modifications, and 
     FIGS. 5, 6 and 7 are elevational views of a detail of three other modifications. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The device represented in FIG. 1 comprises a base-plate 1 intended to be secured to an element of a motor vehicle, diagrammatically represented at 2, the base plate 1 carrying a housing 3. The frame 4 of the apparatus is secured to the base-plate 1 and carries two shafts 5 which are slightly inclined with respect to each other. At an end of each shaft is secured a pulley 6 on which is wound a cable 7. Each of the cables 7 are connected to a safety belt which is not represented. 
     Each shaft 5 carries, at its end opposite the pulley 6, a disc or plate 8 having the shape of a drum and being provided with an inner recess 9. In recess 9 is located an helicoidal blade spring 10 the inner end of which is connected to the shaft 5 and the outer end of which is secured to a pin 11 carried by the frame 4. When a traction force is exerted on one or the other of the cables 7, the corresponding spring 10 is wound and is armed to the later the return of cable. 
     So that the locking of the two cables 7 is ensured in the case of shock or of sudden braking of the vehicle, the device includes locking means comprising a locking stem 12 slidably mounted in a sleeve 13 which is secured to the frame 4 by a base 13a. The end 12a of locking stem 12 has the shape of a wedge adapted to be engaged between the two discs 8 but is shown out from the center thereof. This locking stem 12 is provided with a shoulder 12b which bears a coil return spring 14. Spring 14 surrounds the sleeve 13 and bears on the base 13a of sleeve 13. The locking stem 12 is ended, beyond its shoulder 12b, by a protrusion 12c the end of which is spherical and bears on a concave surface 15 of a control member 16 having the shape of a cap. Control member 16 bears, through spherical feet 16b, on the baseplate 1. A hair spring 17 maintains the control member 16 in its centered position as represented in the drawing. 
     It results from this arrangement that when a sudden deceleration or acceleration of the vehicle occurs, in any direction, the control member 16 is moved laterally, by inertia. This movement produces, by reason of the concavity of surface 15, an axial displacement of the stem 12 with the wedge-shaped portion 12a being wedged between the two discs 8, and locking these two discs. 
     The device represented comprises moreover means allowing the user, when he has closed his belt, to interrupt the effect of the traction force produced by the springs 10 which effect can be constricting or uncomfortable. 
     These interrupt means comprise two small pinches 18, each having two jaws 18a. Each pinch is traversed by one of the cables 7, and the jaws 18a are articulated one to each other at 19 by additional mean not represented. A wire spring 20 acts on these jaws for maintaining them in their open position as represented in the drawing. Each small pinch 18 is provided with a control stem 21 which is constituted by a bent stem able to slide in the direction of arrow 22 and which is ended by a portion 21a having the shape of a loop which surrounds the two jaws 18a. When control stem 21 is moved by the user in the direction of the arrow 22, counter to action of a return spring 23, it ensures tightening of the jaws 18a which lock the cable 7 and prevent the corresponding spring 10 from exerting thereon a traction force which would be transmitted to the belt. Moreover, a slight displacement of the cable 7 produced by a displacement of the small pinch 18 through the effect of a displacement of the control stem 21 slightly slackens the belt and ensures the user a maximum of comfort. 
     Control stem 21 is ended by a portion 21b having the shape of a rack which cooperates with a stop member 24 sliding longitudinally and serving to maintain the control system 21 in its rest position. This stop member 24 can be connected, by a cable 25, to the hanging device of the belt in such a way that, at the moment when the user unhooks the belt, the control member 21 is automatically released, which ensures the loosening of the small pinch 18 and allows the winding up device to operate normally. 
     If the user makes a movement which requires the belt to move, the control member 21 of the small pinch 18 remains in place with the small pinch alone moving with the cable. When the user returns to their normal position, the small pinch returns to the contact of control member 21. Consequently, during this movement, the user is submitted to the traction or return force of the spring 10 of the winding up device. 
     The modification of FIG. 2 distinguishes from the embodiment as hereinbefore disclosed and represented by the fact that the locking stem 12 is replaced by a locking stem 26 rigidly connected with a base 27, the face 28 of which is situated opposite the base-plate 1 and is concave. Control member 29 is provided with a half spherical protrusion 29a on which the base 27 is bearing through concave surface 28. The lateral displacements of the control member 29 which are produced by inertia, produce the axial displacement of the locking stem 26. 
     In the modification of FIG. 3, a locking stem, 30, is provided with a base 30a which is provided with two spherical protrusions 30b and 30c. Protrusions 30b and 30c cooperate, respectively, with two control members 31 and 32 which can both oscillate freely and independently from each other around an axis 33 coaxial with the locking stem 30. The control member 31 is provided with a concave surface 34 which bears the protrusion 30b of the base 30a. The control member 32 is provided with an edge 32a the upper face of which is also concave, at 35, and cooperates with the protrusion 30c of the base 30a. 
     Depending on the direction in which sudden accelerations or decelerations of the vehicle are produced, one or the other or both of the control members 31 and 32, may be moved, by inertia and produce the axial displacement of the locking stem 30. 
     In the modification of FIG. 4, locking stem 36, is rigidly connected with a square base 37 provided with two inclined planes 38 and 39, whose planes are perpendicular to each other. A control member 40, sliding in the direction of arrow 41, bears, through a protrusion 40a, on the inclined plane 38, while a control member 42, articulated at 43 moves in the direction of arrow 44 and cooperates with the inclined plane 39. 
     One or the other or both of these control members 41 and 42, may, when moved by inertia, produce the axial displacement of the locking stem 36. 
     In the embodiment of FIG. 1, the device is a double winding up device, for two belts, and is secured in the middle of the vehicle between the two front seats. However, the present winding up device can be applied to a single belt, as diagrammatically represented in FIG. 5. In this case, the locking stem 12 acts on a single disc 8 and is sustained, at the side, opposite disc 8 by a member 45 of the frame, which can be constituted by the frame 4 itself. 
     In the embodiment of FIG. 1, the stem 12 acts on the axial face of the two discs 8 the axes of which are inclined relative to each other but are situated in a same plane. In the modification of FIG. 6, a locking stem 46, having the shape of a wedge, acts directly on the pulleys 6 of the cables 7, these pulleys having their axes 5 parallel to each other. 
     This modification can be also applied to the case where the winding up device is provided for a single belt, in which case the locking stem 46 will act on a single pulley 6 and will be sustained by a stationary bearing member 49, as represented in FIG. 7.