Abstract:
A part of an electrical connector including, a body, at least one elastic arm which has at least one locking hook attached to the body and extending laterally to the body, the elastic arm being flexible from a locking position wherein the arm is unstressed and close to the body to an unlocking position wherein the arm is stressed and bent away from the body, a slide comprising a window through which passes the elastic arm carrying the hook and wherein the slide slides on the body of the connector between a locking position and an unlocking position and a ramp provided between the slide and the elastic arm so that as the slide moves from the locking position to the unlocking position, the slide acts on the elastic arm to bend the arm and the hook away from the body in the unlocking position.

Description:
The present invention relates to a locking and unlocking device for an electrical connector. 
     BACKGROUND OF THE INVENTION 
     An electrical connector comprises a male part and a female part. To ensure a good connection between these two parts, one of the parts is locked to the other. Several locking devices are known. For example, it is known to use a threaded connection, in which case a housing, for the male part, for example, comprises two tapped holes while the corresponding female part carries two screws, e.g. knurled screws. 
     The disadvantage with this system is that it takes some time to lock and/or unlock. The device is in addition relatively expensive. 
     It is also known practice to fasten one part of the connector to the other part using hooks and hook catches. The hook is on an elastic arm, which itself pivots on part of the connector. To unlock the device, pressure is applied to the free end of the pivoting arm furthest from the hook to release the latter from its hook catch. The hook catch may be a cavity formed in the other part of the connector. 
     The problem with this locking device is its large size, because in order to have enough leverage, the pivoting arm must be relatively long and extend beyond the body of that part of the connector to which this arm is attached. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a locking and unlocking device for a connector of small size. Advantageously, this device has a relatively low cost price. 
     For this purpose, the device which the invention proposes is a locking device for an electrical connector with a male part and a female part, this device comprising at least one locking hook on an elastic arm attached to a first part of the connector to engage with a hook catch formed on the second part of the connector. 
     According to the invention, this device also comprises a slide containing a window through which passes the arm carrying the hook, said slide sliding on the first part of the connector between a locked position in which the hook and the hook catch are engaged and an unlocked position in which the hook is withdrawn from its hook catch, a ramp, cam or the like being provided between the slide and the elastic arm so that as it moves from the locked position to the unlocked position, the slide acts on the elastic arm, to move the hook away from its hook catch. 
     In order to lock the device, all that is required is to push the male part onto the female part or vice versa, the locking device being in the locked position. For unlocking, the slide is operated to move from the locked position to the unlocked position. As the slide moves, its ramp pushes the hook away from its hook catch, thus freeing the male and female parts from each other. 
     In a first embodiment, one edge of the window slides between the elastic arm carrying the hook and the first part, and the ramp is formed on that face of the elastic arm which is nearest to the first part of the connector. In this case, a protuberance may be provided on that face of the elastic arm which is nearest to the first part of the connector, between the hook and the ramp. This protuberance enables the slide to be kept in its locked position. Furthermore, when the slide is being operated, once past the protuberance the slide is clear of that part of the connector to which it is mounted and the slide can be grasped more easily to act on the elastic arms. 
     In a second embodiment, the elastic arm is housed entirely inside the window in the locked position, that edge of the window which is nearest to the hook is beveled on the face facing away from the first part of the connector and the free end of the elastic arm includes a complementary surface to the bevel formed on the edge of the window, in such a way that when the edge of the window slides under the hook, the latter moves away from the first part of the connector and from the hook catch. 
     For a better locking action, the locking device according to the invention advantageously comprises two elastic arms each carrying a hook. In this case, the two elastic arms may for example be connected by a base, thus forming a U-shaped stirrup. The stirrup is preferably formed in two parts assembled together, each part having an elastic arm. By way of example, they may be assembled by mutual engagement of the two parts or by welding. To mount this locking device on one part of the connector, the slide is positioned on the connector and then each part carrying an elastic arm is put in position. Welding, e.g. ultrasound welding, is then carried out to join the two parts of the stirrup together and also to join the stirrup to the connector part. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     However, a clear understanding of the invention will be gained from the following description, with reference to the accompanying schematic drawing, which shows by way of non-limiting examples, two embodiments of a locking device according to the invention. 
     FIG. 1 is a perspective view of a female connector equipped with locking device according to the invention, 
     FIG. 2 is a longitudinal sectional view on cutting plane II—II as marked in FIG. 1, 
     FIG. 3 is a front view of the connector of FIG. 1 in the unlocked position, 
     FIG. 4 is a sectional view on the plane IV—IV as marked in FIG. 2, 
     FIG. 5 is a perspective view of a female part of a connector equipped with an alternative embodiment of a locking device according to the invention, and 
     FIG. 6 is a sectional view on VI—VI as marked in FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1 shows a female part  2  of a connector. The male part  4  of this connector is represented only in outline by chain line. This connector comprises five pins and visible in FIG. 1 are five entrances  6  each designed to take one wire. These five entrances  6  are aligned with each other, and to each of them there corresponds, on the opposite side of the female part  2  from the entrances  6 , a contact  8 . Consequently there are thus five contacts  8  aligned with each other. 
     The female part  2  of the connector is provided with a locking device. This device comprises two elements: a stirrup and a slide  10 . 
     The stirrup is composed of two bent components  12 . These components  12  are welded together to form a U-shaped stirrup. The base of this U is welded to the female part  2  of the connector. The branches of this stirrup each form an elastic arm  14 . Each elastic arm  14  extends along the female part  2  of the connector, parallel to the contacts  8 . The base of the stirrup is at the entrance  6  end, while the free ends of the elastic arms  14  are at the contact  8  end, i.e. at the end of the female part  2  designed to receive the corresponding male part  4 . 
     On its face next to the female part  2  of the connector, each elastic arm  14  comprises a hook  16  designed to engage with a hook catch formed in the male part  4  and not shown in the drawing. This hook catch may for example be similar in shape to the hook  16  but it may also be a recess formed in the male part  4  of the connector. 
     The slide  10  is similarly U-shaped. It comprises a base  18  and two side branches  20 . The female part  2  of the connector sits between the side branches of the slide, the base  18  now being situated at the entrance  6  end. The base  18  of the slide can for example be used for labeling the entrances  6 . In FIG. 1 the first five letters of the alphabet are used for this labeling. The side branches  20  of the slide each include a window  22  through each of which passes an elastic arm  14 . The free end of each side branch  20  of the slide is situated between a hook  16  and the bend of the corresponding bent component  12 . This free end therefore moves between the elastic arm  14  and the female part  2  of the connector. The window  22  is an elongate window allowing the slide to be moved approximately parallel to the direction of the contacts  8 . The length of the windows  22  determines the length of the travel of the slide  10 . The width of this window  22  is approximately equal to the width of the corresponding elastic arm  14 . Thus, each window  22  guides the slide  10  during its sliding movement by interaction with the elastic arms  14 . 
     That face of the elastic arm  14  which is nearest to the female part  2  of the connector includes a ramp  24  in the vicinity of the bent component  12 . This ramp creates a narrowing of the free space left between the elastic arm  14  and the female part  2  of the connector when moving away from the free ends of the elastic arms  14  toward the base of the stirrup. This face on each elastic arm  14  also includes a protuberance  26  located between the ramp  24  and the hook  16 . In order not to impair the elasticity of the elastic arm  14 , a recess  25  can be provided in the bend of the bent component  12 , as shown on the left-hand side of FIG.  3 . On that face of the elastic arm which is nearest the female part there is therefore a cam which forms the ramp  24 . 
     To assemble this locking device, the slide  10  is first placed on the female part  2  of the connector. The bent components  12  are then positioned by inserting them through the windows  22 . The two bent components  12  are then welded together, for example by ultrasound welding, and the resulting stirrup is welded to the female part  2  of the connector. 
     The operation of this locking device is therefore as follows: in the locked position (FIGS.  1  and  2 ), the slide  10  is pushed in so that its base  18  is resting against that face of the female part  2  that includes the entrances  6 . The free end of each side branch  20  of the slide is close to the hooks  16 . To ensure that pressure on the base  18  of the slide does not cause the branches  20  to move the hooks  16 , an end stop  28  is provided on that face of the female part  2  which contains the entrances  6  (FIG.  4 ). The protuberances  26  are at the edge of the corresponding windows  22 , toward the free ends of the side branches  20 . They enable the slide to be kept in its locked position. The female part  2  can thus be clicked onto the male part  4 . The free end of each elastic arm  14  has a chamfer  30  facing towards the female part  2  of the connector for easier snap engagement. 
     Once the female part  2  is in place on the male part  4 , unlocking is effected by pulling on the base  18  of the slide  10 . The base  18  is then moved away from that face of the female part in which the entrances  6  are formed. The side branches  20  of the slide then slide alongside the female part  2  of the connector. The protuberances  26  create an initial slide obstacle. As the free ends of the side branches pass over these protuberances  26 , the elastic arms  14  are pushed slightly away from the female part  2  of the connector without actually disengaging the hooks  16  from their hook catches. Once the slide obstacle has been overcome, the base  18  of the slide will be found to have come away from that face of the female part  2  of the connector in which the entrances  6  are formed. It is now possible to grasp the base  18  of the slide from the rear, so it can now be pulled more easily. As the pulling movement continues, the free ends of the side branches  20  reach the ramps  24 . As the pulling action continues, the elastic arms come away from the female part  2  of the connector and the hooks  16  are no longer engaged with the corresponding hook catches. The connector is thus unlocked. 
     FIGS. 5 and 6 show another embodiment of a locking device designed for the female part  2  shown in FIGS. 1 to  4 . Entrances  6  and contacts  8  therefore appear here also. 
     The locking device presents a similar structure to that described previously: as before, there is a slide  110  and a stirrup made up of two bent components  112 . The stirrup and the slide  110  are likewise U-shaped and are arranged relative to the female part of the connector in the same way as in the first embodiment. Each bent component comprises an elastic arm  114  extending alongside the female part  2  in the same direction as the contacts  8 . At the end of each elastic arm  114  is a hook  116  facing toward the female part  2  of the connector. The slide  110  comprises a base  118  and two side branches  120 . A window  122  is formed in each of the side branches  120 . 
     The differences between this second embodiment and the first embodiment as described above relate primarily to the side branches  120  and the elastic arms  114  of the locking device. When the device is in the locked position, each window  122  accommodates the corresponding elastic arm  114  entirely. A ramp  132  is formed on that edge of the window  122  furthest from the base  118  of the slide. This ramp  132  is formed on the outer face of the corresponding side branch  120 . The free end of the elastic arm  114  is in turn provided with an opposing ramp  136  formed on the side facing towards the female component  2 . 
     Each window  122  is continued by a slot  136  toward the free end of the corresponding side branch  120 . The purpose of this slot  136  is to allow the corresponding hook  116  to pass along it when the slide is pulled from its locked position to its unlocked position. An end stop  138  is provided at the end of each side branch  120  to limit the travel of the slide  110 . 
     The way this locking device works is almost exactly the same as for the first locking device described earlier. In the locked position, the base  118  of the slide  110  is up against that face of the female part in which the entrances  6  are formed. Engaging the female part on the male part occurs in exactly the same way. As before, a chamfer  130  on the hooks  116  facilitates the snap engagement of the hooks  116  on the corresponding hook catches. The device is locked simply by clicking the female part  2  onto the corresponding male part  4 , the locking device being in the locked position in the course of this operation. 
     Unlocking is done by pulling the base  118  of the slide  110  away from the female part  2  of the connector. The ramps  132  of the side branches  120  act on the opposing ramps  134  of the elastic arms  114  to push them away from the female part  2  of the connector. When the slide  110  has been pulled as far as it will go, the free ends of the elastic arms  114  are in abutment against the end stops  138  at the free ends of the side branches  120 . 
     It goes without saying that the invention is not limited to the two embodiments described above by way of non-limiting examples; on the contrary, it encompasses all variants within the scope of the following claims. 
     For instance, the two examples above show two positions for the ramps that enable the elastic arms to be pushed out. Other positions could be envisaged for this ramp, such as for example in the middle of the elastic arms. 
     The elastic arms here constitute the branches of a U-shaped stirrup. It would be possible to have independent elastic arms fixed directly to the female part of the connector. 
     The locking devices described above are mounted on a female part of a connector. The devices according to the invention are also adaptable to male parts of a connector.