FR2708058A1 - Device with positive-locking fastening pin and assembly system employing such a pin - Google Patents

Abstract

The invention relates to a device with positive-locking fastening pin (1) comprising a hollow body (10) in which there is a rod (11) which can move in rotation about a longitudinal axis ( DELTA ) between two extreme positions determined by a pin. The rod (11) includes two fingers (2) which either project or are retracted depending on whether flats (110) are or are not inserted beneath the fingers (2). The fingers have a rounded external shape (20) and are equipped with a shoulder (21). A ring (31) allows the rod (11) to be made to rotate and a spring (12) automatically returns it to a locked position. Application to assembly systems especially for artillery and aeronautics.

Description

 The invention relates to a positive locking fixing pin device.

The invention also relates to a system for mechanical assembly of parts using such a fixing pin and more particularly to an assembly system having the following characteristics:
- assembly by removable obstacle, requiring no tools to remove; and
- assembly locked by obstacle requiring the deliberate action of an operator to remove it, which excludes the risk of inadvertent disassembly.

 The field of the invention covers many applications and, in particular, weapons (medium caliber artillery) and aeronautics.

In Known Art, there are two main types of assembly systems meeting the above characteristics:
- assembly systems using a ball spindle; and
- assembly systems using a pin locked with a pin.

 In the first type of spindle, illustrated by Figures 1 and 2 attached, the locking is usually provided by two balls controlled by a plunger core. In the locked spindle position, the balls are kept projecting by the plunger core pushed by a spring. To unlock the spindle, pull on the plunger core, which causes its release at the balls. These can then be erased and release the spindle.

 In the second type of pin, illustrated in Figures 3 and 4 attached, the locking is provided by an elastic pin.

 The spindle is provided with an orifice at one of its ends into which the pin is introduced, which ensures that the spindle is held in place.

 However, although commonly used, these pins have several drawbacks.

 In the case of ball pins, if they are subjected to a harsh environment, we can witness a disjointing of the balls, which leads to unlocking. Unlocking can also be caused by a displacement of the plunger core.

 In the case of pin pins, the most significant drawbacks are as follows: needing to remove the pin, accessibility of the pin, risk of losing the pin, and risk of forgetting to replace this pin.

 The invention sets itself the aim of overcoming the drawbacks of the devices of known art, some of which have just been mentioned.

 More particularly, it sets itself for purpose a positive locking fixing pin device, for which the risk of unlocking during use is excluded and having improved reliability of the locking system.

 To do this, according to one of the most important characteristics of the invention, the balls are replaced by blocking elements in the form of fingers or similar members, one end of which is spherical or, more generally rounded, and the other end is provided with stop means, for example a shoulder head.

 The projecting fingers are locked by a substantially cylindrical rod held in position by a torsion spring.

 Unlocking is carried out by rotating said rod a fraction of a turn, for example a quarter turn using an operating member to release the fingers towards the inside of the spindle.

 In a preferred embodiment, said operating member comprises a drive ring.

 In an additional embodiment, said operating member comprises a handle with two branches.

 The subject of the invention is therefore a device with a positive locking fixing pin comprising a hollow body having a longitudinal axis of symmetry intended to be introduced into a determined housing, the device having a first state or locked state prohibiting the operations of engagement and disengagement of the hollow body in said housing and a second state or unlocking state authorizing these operations, characterized in that it comprises first means introduced into said hollow body, movable in rotation between first and second determined positions around said longitudinal axis of symmetry, at least one blocking element of elongated shape, disposed in an orifice made at one end of the hollow body and movable in a direction substantially perpendicular to said longitudinal axis of symmetry, this blocking element being controlled by the first ways to be salient compared to the p outer wall of the hollow body in said first state and, at most, flush with this wall in said second state; and second means for controlling the rotation of the first means between said first and second determined positions, so as to position the device in said first state, respectively said second state.

 The invention also relates to a device characterized in that each of said blocking elements has the shape of a finger and in that a first end, turned towards the outside of said hollow body has a rounded shape and the other end is provided with a shoulder disposed inside this hollow body and preventing the ejection of the element towards the outside of the hollow body.

 The invention also relates to a device characterized in that the internal section of the hollow body being circular, said first means consist of a rod with a circular section also comprising a cell at each of said blocking elements, each cell being brought opposite the blocking element associated with it to allow its withdrawal towards the inside of the hollow tube in said second state and the cylindrical wall of the rod pushing this blocking element in said first state.

 The invention also relates to a device characterized in that it further comprises elastic means for automatically returning said rod to said first determined position around said longitudinal axis of symmetry.

 The invention also relates to a device characterized in that said elastic means comprise a torsion spring.

 The invention also relates to a device characterized in that it further comprises means for limiting the amplitude of rotation of said rod around said longitudinal axis of symmetry.

 The invention also relates to a device characterized in that said means for limiting the amplitude of rotation comprise a pin and in that said hollow body comprises a groove in which the pin engages, the length of the groove determining said amplitude.

 The invention also relates to a device characterized in that said amplitude is equal to a quarter turn.

 The invention also relates to a device characterized in that said second means comprise a ring operable by hand.

 The invention also relates to a device characterized in that said second means comprise a handle operable by hand provided with a first branch and a second branch; in that the first branch is secured to said hollow body and the second branch is secured to said first means; and in that these two branches are orthogonal to one another when the device is in said first state.

 The invention finally relates to an assembly system for the implementation of a positive locking fastening pin device according to the above.

 The device according to the invention has several advantages compared to a so-called ball spindle device.

 The balls are replaced by one of the shouldered fingers or similar bodies, trapped positively inside the spindle. In the case of the ball spindle, the crimping of the balls deteriorates very quickly under severe conditions of use.

 The locking according to the invention, obtained by rotation, is insensitive to axial and / or radial accelerations relative to the spindle. There is therefore no possibility of inadvertent unlocking of this fact.

 On the other hand, in a traditional ball spindle, as soon as the spring associated with the plunger core is compressed under the action of an axial force, the balls are erased freely.

The invention will be better understood and other characteristics and advantages will appear on reading the description which follows with reference to the appended figures and among which:
- Figures 1 and 2 relate to a fixing pin device of the so-called ball type;
- Figures 3 and 4 relate to a fixing pin device of the so-called pin type;
- Figure 5 schematically illustrates a positive locking fastening pin device according to the invention;
- Figures 6 to 8 are detail figures of the device of Figure 5, intended to explain more fully its operation;
- Figure 9, on the one hand, and Figures 10 and 11, on the other hand, illustrate, respectively, two alternative embodiments of spindle control means used in the device according to the invention.

 We will first briefly recall the operation of the two types of fixing pin devices according to the known art.

 FIG. 1 diagrammatically illustrates a fixing pin device 1 of the so-called ball type ".

 The fixing pin device will be called "pin" in the following for the purpose of simplification.

The spindle 1 comprises a hollow body 10, generally of cylindrical interior and exterior sections, into which is introduced a plunger core 11 of longitudinal axis of symmetry
We have shown in Figure 1, the two possible extreme positions of this plunger core! position 11 corresponding to a so-called "locked" state (upper part of FIG. 1) and position 111 corresponding to a so-called unlocked state (lower part of FIG. 1).

 The plunger core 11-11 ′ has a clearance 14 at one of its ends (left part in FIG. 1) and is actuated by a spring 12-12 at the other end.

 In the "locked" state, the spring 12 is relaxed while it is compressed (12 ') in the "unlocked" state.

 This spring 12-12 'acts on two balls 13 and 13'.

 In the "locked" state, the balls, as shown in 13 (upper part), are pushed towards the outside of the body 10 of the fixing pin device by the plunger core 11. On the contrary, in the "unlocked" state ", the ball 13 'can enter the clearance 14 formed in the plunger core: position 11' thereof.

 We can therefore release pin 1 from the housing (not shown) in which it is engaged. We have also not shown the control means of the plunger core 11-11 '.

 This device is sensitive to axial forces, that is to say parallel to the axis o (axis of symmetry of the device) along which the plunger core 11-11 'moves. It suffices that the spring 12-12 ′ is compressed, which can occur during violent stresses.

 In addition, as illustrated in more detail in FIG. 2, if the crimping 100 of the balls (for example of the ball 13 in the example illustrated in FIG. 2) deteriorates, these will no longer play their locking role - unlocking and may even come out of their housing.

 Figures 3 and 4 illustrate the second type of fixing pin device according to the known art, that is to say that called "pin". FIG. 4 is a section along A-A of FIG. 3.

 The spindle 1 is constituted as previously of a generally cylindrical body of which one of the ends, or spindle head, is provided with a shoulder 102. This end can be fixed to any device (chassis, etc ..., not shown).

 The other end is provided with an orifice 101 allowing the introduction of one of the branches, 150, of an elastic pin 15. The diameter of this orifice is naturally chosen so that it is slightly greater than that of the branch 150 of pin 15. This is generally straight. The other branch 151 forms the spring proper and follows the external shape of the body 10 of the spindle 1 when the pin is pushed in (locked position). The pin 1 is intended to be engaged in a part 16 to be fixed or driven, in a conventional manner. The latter comprises a channel 160, in which the body 10 of the spindle is slid. Once the body 10 has been fully engaged in said channel 160, the pin 15 is inserted, which locks the two parts, 10 and 16.

 However, although less sensitive to longitudinal forces, this device has the drawbacks which have been previously indicated.

 Also the invention provides a positive locking pin device in which, according to a first important characteristic, the balls are replaced by elongate locking elements, having the general shape of a finger in a preferred embodiment.

 FIG. 5 schematically illustrates a device of this type. In this figure, and the figures which follow, the elements identical or similar to the elements described in relation to Figures 1 to 4 bear the same references and will only be re-described as necessary.

 The cylindrical body 10 is provided at one of its ends (on the left in FIG. 5) with two orifices 100 allowing the introduction of two elongated parts 2, in the shape of a finger as indicated. One of the ends 20 of the parts (turned towards the outside of the body 10) is of rounded shape and, in a preferred variant of the invention, of substantially semi-spherical shape. The other end is provided with a locking means 21 for the part 2 in the orifice 100, for example a collar or a shoulder, which traps it inside the pin 1.

 Inside the body 10, a substantially cylindrical rod 11 has been arranged playing a role similar to the plunger core of FIG. 1, with, however, specific features which will be explained below.

 At the level of the fingers 2, the rod 11 is provided with two flats or superficial cells 110, symmetrically opposite. In the locked state, as illustrated in FIG. 5, the fingers 2 press on the external wall of the rod 11 and these are pushed outwards. Their length is sufficient for them to protrude and form protuberances relative to the external wall of the body 10.

 At the opposite end of this body 10, means 3 for operating the rod 11 have been placed.

 Unlike known art, and more precisely that represented by pin devices of the so-called "ball" type (Figures 1 and 2), the rod 11 is movable in rotation around the axis of symmetry h.

 In the example illustrated, the operating member 3 controlling the rod 11 comprises a ring 31 acting on the end 111 of the rod 11. A cap 30 provided with an orifice 300 in which the said end 111 is threaded is fixed by screwing or any suitable means on the body 10. This cap contains a return spring 12, or torsion spring, as well as various means which will be described below.

 We will now explain the mounting and dismounting of the spindle in a housing, not shown in FIG. 5, but similar to the housing 160 in FIG. 3.

 To mount the body 10 of the spindle 1 in said housing, it is necessary to "erase" the projecting fingers 2 as illustrated in more detail in FIG. 6, which represents the device of FIG. 5, in section along BB, in the lock status. It is assumed, without limiting the scope of the invention, that the shoulders 21 are substantially planar. It is easy to realize that the flats or cells 110 being in planes substantially perpendicular (in the example illustrated) to the planes formed by the outer surfaces of the shoulders 21, the fingers 2 are, as indicated, repelled by the cylindrical rod 11 and form protrusions.

 On the other hand, if said rod 11 is made to turn a quarter of a turn, the flats or cells come opposite the shoulders and are now in position 110 ′ as shown in FIG. 7. The shoulders can be pushed back into position 21 ′, that is to say set back from position 21 (FIG. 6). It follows that the fingers themselves are in position 2 'and that their outer ends in position 20'.

 The depth of the flat or alveolus 110-110 'on the one hand, and the length of the fingers 2-2' on the other hand, are determined so that they, at most, are flush with the surface of the outer wall of the body 10 when mounting the spindle (or unlocked state), as shown in Figure 7. We can then thread the spindle into its housing (not shown).

 In the position which has just been described (FIG. 7), the torsion spring 12 (FIG. 5) is compressed. One end of the spring 12 is made integral with the body 10 or, which amounts to the same thing, with the housing 30, the other end is made integral with the rod 11.

 To rotate the rod 11, action is taken on the ring 31 secured to the end 111 of the rod 11.

The latter is advantageously provided with an orifice 1110 enabling the ring 3 ′ to be threaded, itself not being continuous. The discontinuity 310 allows, by elastic deformation of the ring 31, to engage it in the orifice 1110. Then, still by natural elasticity, it resumes an annular shape. This arrangement is classic.

 When the pin 1 is engaged in its housing (not shown), the fingers 2 are released. To do this, the ring 31 is released. This action has the effect that the torsion spring 12 returns the rod 11 to its initial position. (figure 6). The edges of the rod 11 press again on the base of the shoulders 2 towards the outside of the spindle 1 and keep them projecting.

 Disassembly of the spindle 1 or removal can be simply obtained by performing the reverse operations to those which have just been described.

 In order to obtain reliable locking (position in FIG. 6) and fitting and removal operations carried out with precision, means are advantageously provided for limiting the rotational travel of the rod 11.

 To do this, as shown in FIG. 8 (view in section CC of the device in FIG. 5), the rod 11 can be provided with an orifice 103 in which a pin 33 is engaged. The body 10 is also provided with two grooves 104, each developed on a quarter of a circle for example, symmetrically, and produced in the wall of the body 10 of the spindle 1.

 By this arrangement, the movement of the pin 33 is limited by the opposite walls 1040 or 1041 of these slots 104.

 The amplitude of the rotary movement of the rod 11 is therefore a quarter of a circle and the extreme positions taken by this rod 11 are well defined, the spring 12 automatically recalling the rod in its so-called "locking" position (FIG. 6 ) when the operating member 31, that is to say the ring 31 in the example illustrated, is released, the amplitude of the rotation could naturally be limited to a fraction of a circle different from the quarter circle. This value is not critical, it suffices to plan the location of the flats 110 accordingly.

 As indicated above, one of the main advantages of the device according to the invention is to be insensitive to axial accelerations, the rod 11 not being movable along the axis A, and also to radial accelerations. In addition to the return force of the spring 12, the engagement in the orifices 100 of the locking elements 2 in the form of a finger ensures positive locking and therefore prohibits any untimely unlocking. There is no longer to fear as in the case of a ball spindle (Figures 1 and 2) of problems linked to the deterioration of the crimping.

 The operating member 3 can be produced in different ways without departing from the scope of the invention.

 It can include a control ring 31 as in the device of FIG. 5 which is illustrated in more detail in FIG. 9.

 As illustrated by FIGS. 10 (front view) and 11 (side view), it is also possible to use a handle with two branches, 34 and 35, orthogonal to one another in the "normal" position, that is to say say in the "locked" position (Figure 6).

 The first, 34, is fixed to the cap 30 or what amounts to the same is fixed relative to the body 10 of the spindle 1. The other is secured to the projecting end 111 of the rod 11 (Figure 5).

 This arrangement, unlike that illustrated in Figures 5 and 9; allows only one hand to be required to install and remove the spindle 1. The rotation of one branch relative to the other is symbolized by the arrows F in FIG. 10.

 This part of the spindle, or spindle head 1, can also be provided with a connecting ring (not shown) and thus make the pin I 'captive ". This ring can be fixed alternately on the branches 34

Claims (12)

or 35 of the handle. Naturally, the dimensions of these pins, and in particular the diameters and lengths can be adapted to the precise needs of the use made of them. These dimensions can be expressed either in metric units or in inches. Business, governed by various parameters, such as mechanical resistance, corrosion resistance, etc. The material is also selected according to the intended application. This is an essentially technological choice, within the reach of man. To fix ideas, without being limiting, we can use high-strength alloy steel or stainless steel. As indicated, the invention finds application in many fields: artillery, aeronautics. The pin device can be used in these areas either as an assembly axis or as a hinge axis. The invention is naturally not limited to the sole embodiments precisely described in relation, in particular, to Figures 5 to II. On the contrary, one could only use one finger, this naturally at the cost of a deterioration in the locking qualities offered by the invention. One can, in particular, use more than two finger-shaped locking elements, for example three fingers regularly distributed over the circumference of the body 10 or several fingers stepped along the axis A The control means 3 of the rod 11 can be diverse, as noted. Two particular embodiments have been described in relation to FIGS. 9 to 11. The rod 11 itself is capable of alternative embodiments. It could include, for example, only two cylindrical bearings, close to the two ends of the spindle 1, the rest of the rod having any section. The spring 12 can be replaced by any other suitable elastic return means. The subject of the invention is also, according to a preferred embodiment, a device characterized in that it comprises two blocking elements of elongated shape arranged symmetrically with respect to said longitudinal axis of symmetry. CLAIMS  1. Fixing pin device (1) with positive locking comprising a hollow body (10) having a longitudinal axis of symmetry (n), intended to be introduced into a determined housing (160), the device having a first state or state locking prohibiting the engagement and disengagement operations of the hollow body (10) in said housing (160) and a second state or unlocking state authorizing these operations, characterized in that it comprises first means (11) introduced into said hollow body, movable in rotation between first and second positions determined around said longitudinal axis of symmetry (n), at least one blocking element (2) of elongated shape, disposed in an orifice (100) formed at one of the ends of the hollow body (10) and movable in a direction substantially perpendicular to said longitudinal axis of symmetry (this blocking element being controlled by the first means (11) to be e projecting from the outer wall of the hollow body (10) in said first state and, at most, flush with this wall in said second state; and second means (3) for controlling the rotation of the first means (11) between said first and second determined positions, so as to position the device in said first state, respectively said second state.  2. Device according to claim 1, characterized in that it comprises two blocking elements (2) of elongated shape arranged symmetrically with respect to said longitudinal axis of symmetry (  3. Device according to any one of claims 1 or 2, characterized in that each of said locking elements (2) has the shape of a finger and in that a first end (20) turned towards the outside of said hollow body (10) has a rounded shape and the other end is provided with a shoulder disposed inside this hollow body (10) and preventing the ejection of the element (2) towards the outside of the body hollow (10).  4. Device according to any one of claims 1 to 3, characterized in that the internal section of the hollow body (10) being circular, said first means consist of a rod (11) also circular section having a cell (110 ) at each of said blocking elements (11), each cell (110) being brought opposite the blocking element (2 ') associated therewith to allow its withdrawal towards the inside of the hollow tube (10) in said second state and the cylindrical wall of the rod (11) pushing this locking element (2) in said first state.  5. Device according to claim 4, characterized in that it further comprises elastic means (12) for automatically returning said rod (11) to said first position determined around said longitudinal axis of symmetry (0).  6. Device according to claim 5, characterized in that said elastic means (12) comprise a torsion spring.  7. Device according to any one of claims 4 to 6, characterized in that it further comprises means for limiting the amplitude of rotation of said rod (11) around said longitudinal axis of symmetry (A).  8. Device according to claim 7, characterized in that said means for limiting the amplitude of rotation comprise a pin (33) and in that said hollow body comprises a groove (104) in which engages the pin (33 ), the length of the groove determining said amplitude.  9. Device according to claim 8, characterized in that said amplitude is equal to a quarter of a turn.  10. Device according to any one of claims 1 to 9, characterized in that said second means (3) comprise a ring (31) operable by hand.  11. Device according to any one of claims 1 to 9, characterized in that said second means (3) comprise a handle operable by hand provided with a first branch (34) and a second branch (35); in that the first branch (34) is integral with said hollow body (10) and the second branch (35) is integral with said first means (11) and in that these two branches (34, 35) are orthogonal to each other when the device is in said first state.  12. An assembly system characterized in that it implements a positive locking fastening pin device according to any one of claims 1 to 11.