Anti-unlock device for connector

An anti-unlock screw device (100) for connector designed to maintain the connection between two connection elements (1, 2), includes a cylindrical sleeve (101) provided with a row of saw-tooth notches (105) arranged on an internal circumference of a rear portion. The device also has an internal ring (106) mounted in the rear portion of the cylindrical sleeve so that it can be positioned between the cylindrical sleeve and the first connection element, the internal ring including at least one catch (107) capable of cooperating with the saw-tooth notches of the cylindrical sleeve. A blocking device (110, 111, 112, 113) keeps the internal ring fixed relatively to the cylindrical sleeve in a first sense of rotation (V) and inversely keeps the internal ring free in rotation relatively to the cylindrical sleeve in a second sense of rotation (DV).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention pertains to a device preventing involuntary unlocking between two complementary electrical or optical connection elements, such as a receptacle connector and a plug. More specifically, the invention pertains to an anti-unlock device designed to be fixedly joined to one of two connection elements and to be screwed onto the other connection element in order to prevent any involuntary disconnection of the two connection elements.

In certain applications, especially in the field of aeronautic or automobile connection systems, strong vibrations cause the connection elements to move, leading to a loss of linkage between complementary connection elements. Thus, there are known ways of providing each connection system with a device to lock the linkage between the two connection elements and prevent untimely unlocking. Such a device must make it possible to maintain the connection even when the connection systems are subjected to extreme conditions and especially to strong vibrations.

2. Description of the Prior Art

Thus, there is a known locking device with screw comprising a locking ring provided with saw-tooth notches. The locking ring is fixedly joined to one of the connection elements. It then gets screwed onto the second connection element which is provided with a catch that engages onto the saw-tooth notches of the locking ring during the screw-on process. The screwing-on of locking ring is completed when the two connection elements abut each other. The electrical or other connection is thus guaranteed and theoretically maintained.

However, the distance between the two connection elements is not always identical from one connection system to another. Thus, at the end of the locking processes, it can happen that a catch of the connection element around which the locking ring is screwed gets positioned at the tip or along a slope of one of the saw-tooth notches; of said locking ring. Said connection element is therefore in an unstable position relatively to the locking ring. This means that the vibrations to which the connection system is subjected may cause a slight shifting of the locking ring until the catch is brought to a more stable position between two saw-tooth notches. This shifting leads to an equivalent shift as regards the distance between the two connection elements such as a receptacle connector and a plug. And, in certain cases, the connection elements are then no longer in contact, and the electrical or other connection is no longer obtained. Besides, problems of tight sealing may arise because of this spacing, and this should be avoided in pneumatic connectors or electrical or other connectors that are submerged.

SUMMARY OF THE INVENTION

It is an aim of the invention therefore to propose an alternative to the prior-art anti-unlock screw device, that will maintain the connection between two electrical or optical connection elements even under extreme conditions. It is another aim of the invention to provide an anti-unlock device of this kind that is simple to design and/or to assemble.

To this end, the invention proposes to provide the anti-unlock system with an intermediate ring, mounted between the main body of the anti-unlock device and the connection element to which the assembly has to be screwed. This intermediate ring bears the catch or catches that have to get engaged into the saw-tooth notches of the main body. The main body, which is fixedly joined to a first connection element, is capable of being screwed around a second connection element so as to provide for the connection between said two elements and maintain this connection. There is also a blocking device which possible, in a first sense of rotation corresponding for example to the screwing operation, prevents the intermediate ring from rotating relatively to the main body and, inversely, in a second sense of rotation sense, allows such a rotation. This means that the relationship between the catches and the saw-tooth notches is not modified in one sense of rotation whereas in the other sense of rotation the catches get engaged in the saw-tooth notches. It is thus possible to position the catches in a stable position relatively to the saw-tooth notches before the main body is screwed on to the second connection element and to hold them there throughout said screwing operation. Since the position of the catches is not modified by the locking, it remains identical at the end of the screwing operation whatever the locking distance between the two connection elements. Thus, once the anti-unlock system is in a locked position around the corresponding connection element, it is not possible to have any untimely shifting whatsoever of the catches relatively to the saw-tooth notches. The engagement of the catches relatively to the saw-tooth notches takes place only when the main body is unscrewed. Thus, the advantages of such a system using catches/saw-tooth notches are maintained in the anti-unlock system of the invention, without its drawbacks.

An object of the invention therefore is an anti-unlock screw device for connector, especially electrical connectors, designed to maintain the connection between two connection elements, the device comprising:a cylindrical sleeve designed to be mounted so as to be fixed in translation and free in rotation around a first connection element, said sleeve being provided:

at a front portion, with an internal thread designed to cooperate with an external thread made on a second connection element when the first connection element is engaged in the second connection element, and

at a rear portion, with a row of saw-tooth notches arranged on an internal circumference of said rear portion, said saw-tooth notches extending radially towards the interior from the internal wall of the rear portion,an internal ring mounted coaxially in the rear portion of the cylindrical sleeve so that it can be positioned between the cylindrical sleeve and the first connection element, the internal ring comprising at least one catch capable of cooperating with the saw-tooth notches on the rear portion of the cylindrical sleeve,characterized in that it comprises a device for blocking by friction, capable of cooperating with a friction wall to keep said internal ring fixed in rotation relatively to the cylindrical sleeve in a first sense of rotation and inversely to keep said internal ring free in rotation relatively to the cylindrical sleeve in a second sense of rotation, contrary to the first sense of rotation, so as to permit the engaging of said at least one catch into the saw-tooth notches.

The term “internal ring” is understood to mean a circular ring designed to be placed against the internal wall of the cylindrical sleeve to extend coaxially with said cylindrical sleeve and the connection element, so as to be interposed between the cylindrical sleeve and the first connection element, for example a plug, when the anti-unlock device of the invention is in use.

The terms “front portion” and “rear portion” of the cylindrical sleeve are understood with reference to the sense of the connection, the front portion being the portion directed towards the complementary connection element and the rear portion being the opposite portion.

The term “device for locking by friction” is understood to mean a device capable of preventing the rotation of the internal ring in one of the two senses of rotation of the cylindrical sleeve around the second connection element, by contact with a wall, for example a smooth wall.

Advantageously, the first sense of rotation corresponds to the sense of rotation for screwing the cylindrical sleeve on to the second connection element. The second sense of rotation then corresponds to the sense of rotation to enable the unscrewing of the cylindrical sleeve from the second connection element.

Thus, the blocking device of the invention blocks the engagement of the catches in the saw-tooth notches during the screwing operation, for example when the anti-unlock device is rotated clockwise relative to the first connection element. Thus, the blocking device permits such an engagement in the anticlockwise sense.

Classically, the internal ring is provided with at least one catch positioned so as to be facing a row of saw-tooth notches, for example preponderantly, made in the internal wall of the cylindrical sleeve at the rear portion of said sleeve.

Advantageously, in the screwing direction, the catch is in a stable position between two saw-tooth notches. The catch then cannot get engaged in the saw-tooth notches.

In one embodiment, the friction wall may be an insert designed to be mounted so as to be fixed around the first connection element. In another embodiment, the friction wall may be directly made on the external wall of the first connection element.

According to the invention, the blocking device may advantageously comprise a first elastic retracting or return means such as a spring and a bead or another blocking element positioned in a through housing made in the thickness of the internal ring.

In the first sense of rotation, the bead is free in rotation in its housing, thus enabling the internal ring to rotate relatively to the first connection element. More specifically, the internal ring rotates at the same time as the cylindrical sleeve. Inversely, in the second sense of rotation, the bead comes into contact with the friction wall or walls and counters the rotation of the internal ring in the cylindrical sleeve. The internal ring therefore cannot rotate at the same time as the cylindrical sleeve and remains fixed relatively to the first connection element so that the catch on the internal ring gets engaged in the saw-tooth notches of the cylindrical sleeve.

For example, in order to enable the bead of the blocking device to cooperate with the friction wall to counter the rotation of the internal ring, said through housing has a narrowed feature capable of blocking the rotation of the bead in the second sense of rotation.

The invention also pertains to a plug for a connector, especially for an electrical connector, provided with an anti-unlock device according to the invention. Similarly, the invention pertains to a connection assembly comprising a plug, a receptacle connector and an anti-unlock device according to the invention.

MORE DETAILED DESCRIPTION

FIG. 1shows an exploded view of the anti-unlock screw device100according to one embodiment of the invention.

The anti-unlock device100has a cylindrical sleeve101designed to be mounted so as to be fixed in translation and free in rotation around a first connection element, such as a plug1(FIG. 2A).

The cylindrical sleeve101is provided with a front portion102designed to be screwed onto a second connection element such as a receptacle connector2(FIG. 2A). To this end, the internal wall of the front portion102of the cylindrical sleeve101is provided with a thread117(shown in detail inFIG. 2B) complementary to a thread6made on the external wall7of the receptacle connector2(FIG. 2B). An internal wall104of a rear portion103of the cylindrical sleeve101is provided with saw-tooth notches105. More specifically, the saw-tooth notches105extend radially from the internal wall104of the cylindrical sleeve towards the interior of said sleeve101.

An internal ring106is designed to be mounted in the cylindrical sleeve101. The internal ring106is provided with two catches107made on the external wall108of said internal ring106. The catches117extend radially outwards so as to be facing the saw-tooth notches105of the cylindrical sleeve101(FIG. 3).

In the embodiment shown in the figures, the catches107are two in number but this number could be smaller or greater. Furthermore, order to have the elasticity required for getting engaged, the catches107are advantageously mounted at the end of flexible arms so that they can bend and thus be capable of passing into each of the saw-tooth notches105.

Housings110or through holes are hollowed out in the thickness of the internal ring106from an internal wall of said internal ring106. The term “internal wall of the internal ring106” is understood to mean the wall pointing towards the interior of said internal ring106opposite the external wall which, for its part, is pointed towards the cylindrical sleeve101. An elastic element111and a bead112are housed in each housing110(FIG. 3). The housing110as well as the springs111and the beads112belong to the blocking device of the invention.

Naturally, a greater or smaller number of housings110(and corresponding beads and springs) can be planned.

The anti-unlock device100according to this embodiment of the invention also has a circular base113designed to be mounted around the body of the plug1(FIG. 2A) so as to be attached to the external wall5of said plug1. The circular base113is provided with a side wall120extending axially and designed to extend along the external wall of the body of the plug1, and a radial wall121extending radially from the longitudinal wall120towards the exterior. Thus, when the anti-unlock device100is mounted, the internal ring106housed in the cylindrical sleeve101surrounds the longitudinal wall120of the circular base113and rests on the radial wall121.

A spacer114is positioned against the internal ring106so as to cover the face of the internal ring106opening to the exterior of the cylindrical sleeve and opposite the face of said internal ring resting against the radial wall121of the circular base113. The spacer114has a circular and flat shape.

Classically, the cylindrical sleeve101is held so as to be fixed in translation on the body of the plug1by means firstly of a radial stop3and secondly a circlip115housed in a notch4made on the external wall5of said of plug body1. More specifically, in the example described herein, the radial stop3is formed by a circular protruding feature extending radially towards the exterior, from the external wall5of the plug body1.

Thus, when the internal ring106, the circular base113and the spacer114are mounted in the cylindrical sleeve101, itself mounted around the plug body1, each housing110on the internal ring106is demarcated on the internal side by the radial wall121of the circular base and on the external side by the attached spacer114(not shown inFIG. 3).

Each housing110extends in the perimeter of the internal ring106. A first portion122of the housing110(FIG. 3) has a space sufficient to receive the spring111and the bead112while at the same time enabling a free rotation of the bead112in its housing110. A second portion123of the housing110has a narrowed feature118such that a height of the housing, at this narrow portion118, is smaller than the diameter of the bead112. Thus, if the bead112is pushed towards the narrow portion118, for example by the spring111, said bead112is blocked in rotation and rubs against the radial wall121of the circular base113and against the spacer114. Inasmuch as the circular base113and the spacer114are fixed relatively to the plug1, these frictional forces counter the rotation of the internal ring106relatively to the plug1.

The connection and the locking of the plug1to the receptacle connector2are done conventionally (FIGS. 2A and 2B). Initially, the receptacle connector2provided with an insert comprising contacts (not shown) and the plug1, also provided with an insert and contacts (not shown) are connected to each other by a motion of translation. Then, the cylindrical sleeve101is screwed onto the receptacle connector2until the receptacle connector2mechanically abuts the plug1.

During this step of screwing on along a first sense of rotation V, the catches107on the internal ring106do not engage into the saw-tooth notches105of the cylindrical sleeve101. For example, the saw-tooth notches105have a shape such that the catches107remain fixed in position between two saw-tooth notches (FIG. 3) during the screwing operation. Thus, when the cylindrical sleeve101is screwed around the body of the receptacle connector2, the internal ring106rotates at the same time as the cylindrical sleeve101around the receptacle connector2and the plug1. The blocking device is not actuated. More specifically, each bead is free in rotation in its housing110. The rotation of the internal ring106is therefore accompanied by the rotation of the beads112in their housing110. Indeed, the shape and orientation of the housings110are such that the bead, during the screwing operation, is held in the first portion122of its housing110.

Thus, once the plug1abuts the receptacle connector2, the catches107are in the same stable position as they were before the locking, i.e. between two saw-tooth notches105. This position therefore cannot be modified in an untimely way, for example by strong vibrations.

When it is desired to detach the plug1from the receptacle connector2, the anti-unlock device100is unscrewed by turning the cylindrical sleeve101along a second sense of rotation DV so that the plug1can be withdrawn by translation. During this rotation DV, each bead112in the corresponding housing110is pushed back by the spring111into the portion123comprising the narrowed feature118. Indeed, the spring111is fixed into the first portion122and the bead112for its part is positioned between the spring111and the narrowed feature118. Thus, during the rotation in the unscrewing sense DV, the bead112is pushed by the spring111in the sense opposite to that of the unscrewing, towards the narrowed feature118. The bead112thus wedged into the narrowed feature118, rubs against the radial wall121of the circular base113and against the spacer114so that it can no longer roll. The internal ring106is then fixed relatively to the circular base113which itself is fixed relatively to the plug1. Thus, the internal ring106is rotationally blocked relatively to the plug1when the cylindrical sleeve101is unscrewed from the base2.

This means that the unscrewing of the cylindrical sleeve101applies force to the catches107. The catches107get engaged into the saw-tooth notches105of the cylindrical sleeve101. The presence of these saw-tooth notches105and catches107in the anti-unlock device100of the invention therefore dictates the application of a major degree of force to carry out the unscrewing, said unscrewing being accompanied by a clicking noise informing the user of said unscrewing.