FR2815659A1 - Lock for slide mounted in guide used as safety lock on missile comprises locking pin and weight which moves it to unlocked position and is mounted in sealed casing filled with fluid which dampens its motion as it flows through diaphragm - Google Patents

Abstract

The lock for a slide mounted in a guide comprises a locking pin (2) and a weight (4) which moves the pin from the locked position to the unlocked position. These are mounted in a sealed casing (8) filled with an incompressible fluid (12) which dampens the motion of the weight as it flows through a diaphragm (28).

Description

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PASSIVE SECURITY DEVICE LIFTED BY A
ACCELERATION
The invention relates to the field of secure devices and means for securing such devices. These securing means consist for example of a lock.

dans la suite tiroir, par rapport à un support, tant que ce support n'a pas subi une accélération correspondant à un profil donné. En état de sécurité, c'est à dire avant que le support n'ait subi cette accélération, le doigt de verrou constitue un obstacle mécanique au déplacement du tiroir. En état de fonctionnement, c'est à dire après que le support ait subi cette accélération, la sécurité est levée et le déplacement du tiroir est autorisé. In this case, the lock comprises a locking pin which prevents the displacement of a movable member of a mechanism, an element that is called

in the following drawer, with respect to a support, as long as this support has not undergone an acceleration corresponding to a given profile. In safety state, that is to say before the support has undergone this acceleration, the lock finger is a mechanical obstacle to the movement of the drawer. In operating condition, ie after the carrier has undergone this acceleration, the safety is lifted and the movement of the drawer is allowed.

 Such locks are mounted, for example, on control members such as actuators, hydraulic supply drawers, de-exchangers, etc., that is to say members in which the movement of the slide can be a translation, a rotation or a combination of both.

 These mechanical drawers must be secured, so as not to be triggered during, for example, the phases of life on the ground and / or carriage before firing of the machines on which they are mounted, such devices being for example missiles.

 Such drawers are most often secured by securing their power supply (electrical) or by devices themselves controlled by a supply of energy (electrical) delivered by the machine during or after the sequence of launch.

 An object of the invention is to provide a more compact accelerometric latch than are those of the prior art.

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 This object is achieved, according to the invention, by means of a safety lock intended to secure a mechanism comprising a movable drawer capable of guided movement relative to a support, this lock being characterized by the fact that it comprises - a finger latch can occupy at least one position, said safety position, in which it blocks the movement of the movable drawer, and a position, said operating position, in which this displacement is made possible, - a mass of inertia able to move the latch finger, under the action of an acceleration, between the safety position and the operating position, and a hermetic enclosure containing an incompressible fluid, the displacement of the mass of inertia in the enclosure being damped by the fact that it is slaved to the passage of fluid through a diaphragm.

sécurisation du tiroir mécanique, mais en outre la masse d'inertie se déplaçant dans l'enceinte, le verrou selon l'invention peut être réalisé de manière plus compacte. Thus, the safety lock according to the invention constitutes a mechanical obstacle to the movement of a mechanical slide, this mechanical obstacle being controlled by a mass of inertia whose displacement is damped. This damping avoids the displacement of the mass of inertia during a mechanical shock and thus prevents movement of the mechanical drawer, even in case of inadvertent tripping by control means, such as power supply systems, located upstream in the process of activating the mechanical drawer. Such a lock thus fulfills a function of

securing the mechanical drawer, but also the mass of inertia moving in the enclosure, the lock according to the invention can be made more compact.

 Advantageously, the lock according to the invention comprises the following optional features taken independently of one another or in combination: the enclosure is rigid; the enclosure comprises a wall enclosing the latch finger, able to be cut when the latch finger is in the operating position and

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 that the movable drawer moves relative to the support (104); the diaphragm consists of at least one passage pierced through the mass of inertia; - It comprises at least one ball in a housing, this housing being obstructed when the latch finger is in the operating position, so as to make it impossible to return the latch finger in the safety position; and the enclosure comprises compressible and extensible parts having functions, such as resetting the latch or compensating for the expansion of the fluid.

- une masse d'inertie apte à déplacer le doigt de verrou, sous l'effet d'une accélération, entre la position de sécurité et la position de fonctionnement, et - une enceinte hermétique contenant un fluide incompressible, le déplacement de la masse d'inertie dans l'enceinte étant amorti par le fait qu'il est asservi au passage du fluide à travers un diaphragme. According to another aspect, the invention is a mechanism comprising a movable drawer, a support and a latch, the movable drawer being able to move guided relative to a support, this mechanism being characterized by the fact that the lock comprises - a lock finger that can occupy at least one position, said safety position, in which it blocks the movement of the lock and a position, said operating position, in which this movement is made possible,

a mass of inertia able to move the latch finger, under the effect of an acceleration, between the safety position and the operating position, and a hermetic enclosure containing an incompressible fluid, the displacement of the mass of inertia in the enclosure being damped by the fact that it is slaved to the passage of fluid through a diaphragm.

- la figure 1 représente, schématiquement en perspective une vue semi arrachée d'un mode de réalisation d'un verrou conforme à la présente invention ; - la figure 2 représente, schématiquement en coupe selon un plan passant par son axe de symétrie cylindrique, le verrou représenté sur la The invention will be better understood with the aid of the detailed description which follows and references to the drawings in which:

- Figure 1 shows, schematically in perspective a semi-broken view of an embodiment of a lock according to the present invention; FIG. 2 represents, schematically in section along a plane passing through its cylindrical axis of symmetry, the lock represented on FIG.

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 Figure 1, the latter being in the safety position on a drawer; - Figure 3 shows, schematically in a view similar to that of Figure 2, the latch corresponding to Figures 1 and 2, in the operating position; - Figure 4 shows, schematically in a view similar to that of Figures 2 and 3, the latch corresponding to Figures 1 to 3, in the operating position, the drawer has been moved; - Figure 5 illustrates the operating principle of a lock according to the invention, schematically by a section parallel to its axis of movement; and FIG. 6 also illustrates the principle of operation of a lock according to the invention, by a schematic view in section parallel to its axis of displacement.

 An advantageous embodiment of the lock according to the invention is described in detail below.

 As represented in FIG. 1, the latch 1 according to the invention comprises a latch finger 2, a mass of inertia 4, a spring 6, a hermetic enclosure 8 and a locking sub-assembly 10. The enclosure 8 is filled with an incompressible fluid 12.

18 s'étendant à partir d'une cavité 20 s'enfonçant au centre du sommet de la tête 16, pour déboucher dans la région du doigt de verrou 2 située à la base de la tête 16, dans zone de jonction du cylindre plein 14 et de cette tête 16. According to this embodiment the lock has a cylindrical symmetry around a 0-0 axis. The latch finger 2 consists of a solid cylinder 14 surmounted by a head 16. The head 16 has four channels

18 extending from a cavity 20 sinking in the center of the top of the head 16, to open in the region of the latch finger 2 located at the base of the head 16, in the junction zone of the full cylinder 14 and this head 16.

 The mass of inertia 4 is formed of a hollow cylinder in the axial region. This axial region comprises, at one of these ends, a recess 22 intended to receive the head 16, surmounted by a first chamber 24 itself surmounted by a second chamber 26.

 The first chamber 24 and the cavity 20 communicate with each other via a diaphragm 28.

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 The mass of inertia 4 also comprises on its surface perpendicular to the axis 0-0 and opposite to that in which the recess 22 is formed, a circular notch 30 intended to receive one end of the spring 6.

ses extrémités par une cloison 34 ou 36 perpendiculaire à l'axe 0-0. The enclosure 8 is formed of a cylindrical wall 32 closed to each of

its ends by a partition 34 or 36 perpendicular to the axis 0-0.

The internal diameter of the cylindrical wall 32 is slightly greater than the diameter of the peripheral cylindrical surface of the mass of inertia 4.

Thus, the mass of inertia 4 can slide along the axis 0-0, inside the chamber 8, but limiting as much as possible the flow of the fluid 12, between the cylindrical wall 32 and the enclosure 8.

 One 34 of the partitions 34 and 36 has a circular opening 38 intended for the passage of the cylinder 14 of the latch finger 2. But this opening 38 is closed by a glove finger 40 extending parallel to the axis 0-0 towards the outside of the enclosure 8. The thimble 40 is sealed to the fluid 12 at the peripheral edge of the opening 38. The thimble 40 has a cylinder shape whose end is closed by a partition perpendicular to the 0-0 axis. The internal diameter of this cylinder is slightly greater than the external diameter of the cylinder 14 of the latch finger 2, so as to allow sliding of the latch finger 2 in the thimble 40.

 The thermowell 40 is advantageously made of stainless steel.

The thimble 40 has an annular zone 42 at which its cylindrical wall is thinned so as to facilitate the cutting of the closed end of the thimble 40, upon removal of the latch finger 2, from this end. glove finger 40.

 The other 36 of the partitions 34 and 36, that is to say the one opposite to that on which the glove finger 40 is mounted, also comprises a central opening intended for the passage and fixing of the locking subassembly 10.

 The locking sub-assembly 10 generally has a symmetry

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 cylindrical around the 0-0 axis. It comprises a shaft 42 perpendicular to the wall 36.

 The shaft 42 is sealingly connected to this partition 36. The shaft 42 has an inner portion 44 and an outer portion 46, to the enclosure 8.

 The outer portion 46 is closed by a plug 48. The cylindrical wall of the barrel 42 is pierced, near the end of the inner portion 44, two passages 50 for the passage of a ball 52 whose diameter is slightly lower to that of a passage 50.

 The shaft 42 is adapted to receive a rod 54 slidably mounted along the axis 0-0.

 The inner wall of the barrel 42 has a shoulder 55 for housing and locking an axial end of a helical spring 56 whose other end is abutting on a flange 58 of the rod 54.

The coil spring 56 is mounted in compression between the barrel 42 and the rod 54. The rod 54 has an annular restriction 60 in which the balls 52 can be housed. The second chamber 26 holds the balls 52 in the restriction 60. The restriction 60 is tapered so as to facilitate the exit of the balls 52 thereof, when the balls 52 are released from the second chamber 26. If the balls 52 come out of this restriction 60, the rod 54 back in the barrel 42, to the stopper 48, under the effect of the relaxation of the spring 56.

As shown in Figure 2, the latch 1 is intended to be mounted on a mechanism 100. In Figure 2, the latch 1 is in the safety position. This mechanism 100 is for example an actuator. It comprises a movable drawer 102 and a support 104. The support 104 corresponds to the body of the mechanism 100. The movable drawer 102 is able to move relative to the support 104. The movable drawer 102 comprises a mortise 106.

 Figure 3 shows the latch 1 mounted on a mechanism, according to a view similar to that of Figure 2, but in the operating position. The latch finger 2 and the mass of inertia 4 have been moved along the 0-0 axis under the effect of an appropriate profile acceleration. Fluid 12 is passed to

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travers le diaphragme 28, de la partie située entre la cloison 36, sur laquelle est monté le sous ensemble de verrouillage 10, et la masse d'inertie 4, vers la partie située entre la cloison 34, sur la quelle est monté le doigt de gant 40, et la masse d'inertie 4. Le ressort 6 est comprimé. La deuxième chambre 26 a été déplacée le long du fût 42 du fait du déplacement de la masse d'inertie 4, libérant ainsi les billes 52. Grâce à la forme biseautée de la restriction 60 les billes 52 s'écartent de l'axe 0-0, lors du déplacement de la tige 54 vers le bouchon 48 sous l'effort de détente du ressort 56. La tige 54 vient en butée sur le bouchon 48. Le ressort 6 repousse la masse d'inertie 4 vers la cloison 34 sur laquelle est montée le doigt de la gant 40. Mais ce mouvement de la masse d'inertie 4 est bloquée par les billes 52 coincées entre la première 24 et la deuxième chambre 26, l'encombrement de la tige

54, hors de la restriction 60, et des billes 52 étant trop important pour que celles-ci rentrent à nouveau dans la deuxième chambre 26.

through the diaphragm 28, of the part situated between the partition 36, on which the locking subassembly 10 is mounted, and the mass of inertia 4, towards the part situated between the partition 34, on which the finger of the glove 40, and the mass of inertia 4. The spring 6 is compressed. The second chamber 26 has been moved along the barrel 42 due to the displacement of the mass of inertia 4, thus releasing the balls 52. Thanks to the beveled shape of the restriction 60 the balls 52 deviate from the axis 0 -0, during the displacement of the rod 54 towards the plug 48 under the relaxation force of the spring 56. The rod 54 abuts the plug 48. The spring 6 pushes the mass of inertia 4 towards the partition 34 on which is mounted on the finger of the glove 40. But this movement of the mass of inertia 4 is blocked by the balls 52 wedged between the first 24 and the second chamber 26, the size of the rod

54, out of the restriction 60, and the balls 52 being too important for them to return to the second chamber 26.

In this operating position, the latch finger 2 is blocked, the end of the locking finger opposite the head 16, being retracted into the support 104. Only the closed end of the glove finger 40 remains in the mortise 106.

As shown in FIG. 4, if the movable drawer 102 is moved relative to the support 104, it causes the end of the thimble 40 to break in the mortise 106.

 The principle underlying the operation of the lock 1 according to the invention is described below.

 The lock 1 according to the invention meets the two following functional objectives.

la force du ressort 6 doit être suffisante pour empêcher la masse d'inertie 4 et le doigt de verrou 2 d'être déplacés sous l'action des forces gravitationnelles (voir fig. 5). Ainsi, si FRA est l'effort du ressort 6 en position de sécurité, m est la masse de la masse d'inertie 4 et du doigt de verrou 2, g - In the safety position the latch finger 2 must, whatever its position, on the ground in particular, remain engaged in the mortise 106. For that

the force of the spring 6 must be sufficient to prevent the mass of inertia 4 and the latch finger 2 from being displaced by the action of the gravitational forces (see Fig. 5). Thus, if FRA is the force of the spring 6 in the safety position, m is the mass of the mass of inertia 4 and the latch finger 2, g

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is the gravitational acceleration and FF represents the forces of friction, one must have
FRA> m.g + FF - Moreover, the spring 6 must not prevent the displacement of the mass of inertia 4 and the latch finger 2 under the effect of an acceleration y of a few tens of m. s-2, which one wishes that the profile is suitable to lift the security of the control device (see Fig. 6). So if FRB is the force exerted by the spring 6, one must have m. # 039> FRB + FF
Table 1 below groups by way of example values of the various quantities mentioned above and adapted to provide the desired operation of the lock 1 according to the invention.

TABLE 1

<Tb>
<tb> ENG <SEP> 4N
<tb> FRB <SEP> 6 <SEP> N
<tb> Ff <SEP> 1 <SEP> N
<tb> M150g
<tb> g <SEP> 9, <SEP> 81 <SEP> m. <SEP> s-2
<tb> y50 <SEP> m. <SEP>s'
<Tb>

Claims (7)

 1. Security lock for securing a mechanism comprising a movable drawer (102) capable of guided movement relative to a support (104), this lock (1) being characterized in that it comprises - a lock finger (2) can occupy at least one position, said safety position, in which it blocks the movement of the movable drawer (102), and a position, said operating position, in which this displacement is made possible, - a mass of inertia (4) able to move the latch finger (2), under the action of an acceleration, between the safety position and the operating position, and - a hermetic enclosure (8) containing an incompressible fluid (12) , the displacement of the mass of inertia (4) in the enclosure (8) being damped by the fact that it is slaved to the passage of the fluid (12) through a diaphragm (28).  2. Security lock according to claim 1, characterized in that the enclosure (8) is rigid.  3. Security lock according to one of the preceding claims, characterized in that the enclosure (8) comprises a wall (40) enveloping the latch finger (2), adapted to be cut when the latch finger (2). ) is in the operating position and that the actuating element (102) moves relative to the support (104).  Safety lock according to one of the preceding claims,

 characterized by the fact that the diaphragm (28) consists of at least one passage pierced through the mass of inertia (4).  5. Security lock according to one of the preceding claims, characterized in that it comprises at least one ball (52) in a housing, this housing being obstructed when the latch finger (2) is in the operating position, in such a way as to render impossible a return of the <Desc / Clms Page number 10>  lock finger (2) in the safety position.

6. Security lock according to claim 1, characterized in that the enclosure (8) comprises compressible and extensible parts having functions, such as the reset of the lock (1) or the compensation of the expansion of the fluid (12). ). 7. Mechanism (100) comprising a movable drawer (102), a support (104) and a latch (1), the movable drawer (102) being able to move guided relative to a support (104), characterized by the that the latch (1) comprises a latch finger (2) that can occupy at least one position, said safety position, in which it blocks this displacement and a position, said operating position, in which the movement of the lock is rendered possible, a mass of inertia (4) able to move the latch finger (2), under the effect of an acceleration, between the safety position and the operating position, and a hermetic enclosure (8) containing a fluid (12) incompressible, the displacement of the mass of inertia (4) in the enclosure (8) being damped by the fact that it is slaved to the passage of the fluid (12) through a diaphragm (28).