Abstract:
The device for protecting a connector comprising two mutually engageable connector elements itself comprises for each connector element, a resilient tubular sleeve having one end configured to be fastened to a respective connector element by surrounding it in leaktight manner, and having a length at rest that is sufficient for it to be cantilevered out beyond one end of the connector element carrying the resilient sleeve, the cantilevered-out end including spring blades for flattening the sleeve and holding the corresponding lips pressed resiliently one against the other.

Description:
[0001]    The present invention relates to a device for protecting the engageable elements of a connector. 
       BACKGROUND OF THE INVENTION 
       [0002]    It is known that a connector coated with mud is difficult to clean because access to certain portions of the connector is very constrained. Mud impedes mechanical and electrical operation of the connector. 
         [0003]    In order to protect the mutually engageable elements of a connector against mud, regardless of whether the mud is splashed onto the connector element or the connector element becomes immersed in mud, proposals have been made to place a plug on the connector element or to provide a piston incorporated in the connector element and urged by a spring to a position in which the piston surrounds the connection members of the connector element so as to fill the space between the connection members, and thus prevent mud from penetrating between the connection members. 
         [0004]    Such devices are not satisfactory. When a plug is used to protect a connector element, the plug needs to be withdrawn when the connector element is to be used for connection to another connector element. There is then a risk of the user, for lack of time, forgetting or omitting to put the plug back into place. The plug can also be lost, and even if it is attached to the connector element, there is a risk of it receiving mud or of being dropped into mud, so that it is no longer possible to close the connector element with the plug. When using a piston, mud runs the risk of accumulating in the interstices between the connection members and the piston, so that it rapidly becomes impossible to move the piston, and thus to disengage the connection members. 
       OBJECT OF THE INVENTION 
       [0005]    An object of the invention is to provide a protection device that is easy to handle and that provides effective protection. 
       SUMMARY OF THE INVENTION 
       [0006]    In order to achieve this object, the invention provides a device for protecting a connector comprising two engageable connector elements, the device comprising a resilient tubular sleeve for at least one connector element, the sleeve having one end fastened to a connector element and surrounding it in leaktight manner, and having a length at rest that is sufficient for it to be cantilevered out beyond one end of the connector element carrying the resilient sleeve, the cantilevered-out end having means for flattening the sleeve and holding the corresponding lips pressed resiliently against each other. 
         [0007]    Thus, the resilient tubular sleeve remains permanently attached to the connector element it protects, and therefore it does not risk being lost, and it is opened at the moment of engagement with the other connector element in such a manner that the risk of mud penetrating into the inside of the protective sleeve is minimized. 
         [0008]    In an advantageous version of the invention, the means for flattening the sleeve comprise at least one spring blade extending perpendicularly to a longitudinal direction of the sleeve and embedded in wall segments adjacent to the flat end. Thus, the force with which the lips are pressed against each other is increased. 
         [0009]    According to another advantageous aspect of the invention, the spring blade includes curvature about an axis that is parallel to the spring blade, the curvature having a concave side facing towards the corresponding lip. Thus, the force holding the lips against each other is further increased. 
         [0010]    According to another advantageous aspect of the invention, each spring blade is of width that decreases going from a central zone of the blade towards its ends. Thus, when the sleeve is opened, a circular shape is more easily obtained. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Other characteristics and advantages of the invention appear on reading the following description of two particular, non-limiting embodiments, given with reference to the accompanying figures, in which: 
           [0012]      FIG. 1  is a perspective view in the closed position of a protective sleeve constituting a first embodiment of the invention; 
           [0013]      FIG. 2  is a perspective view analogous to the view of  FIG. 1  showing the sleeve in the open position; 
           [0014]      FIG. 3  is a section view on plane III of  FIG. 1 ; 
           [0015]      FIG. 4  is a section view analogous to that of  FIG. 3 , for an open position of the sleeve; 
           [0016]      FIG. 5  is a plan view of a spring blade of the invention shown flat; 
           [0017]      FIG. 6  is a diagrammatic section view on an axial plane showing two cylindrical connector elements fitted with a protective device of the invention and disposed facing each other, prior to engagement; 
           [0018]      FIG. 7  is a view analogous to that of  FIG. 6 , in an intermediate stage during engagement; 
           [0019]      FIG. 8  is a view analogous to that of  FIG. 6  for an engaged position of the connector elements; 
           [0020]      FIG. 9  is a fragmentary perspective view of a second embodiment of the invention; 
           [0021]      FIG. 10  is a section view analogous to that of  FIG. 6  showing two connector elements in the second embodiment of the invention; and 
           [0022]      FIG. 11  is a section view analogous to that of  FIG. 10 , the connectors being shown in an engaged position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    With reference to  FIG. 6 , the protective device of the invention is designed to protect a connector comprising two engageable connector elements land  2 . In the embodiment shown, the connector element  1  comprises a base  3  for fastening to an apparatus wall (not shown). A cylindrical bushing of circular section  4  is fastened to the base  3  and contains a connection member  5  having metal-plated holes  6  connected to connection wires. The connector element  2  comprises a cylindrical bushing of circular section  7  for mounting at the end of a cable, and containing a connection member  8  fitted with pins  9  coinciding with the metal-plated holes  6 . 
         [0024]    With reference to  FIGS. 1 to 8 , in a first embodiment of the invention, the connector element  1  is fitted with a resilient tubular sleeve  10 , e.g. a rubber sleeve. At one end, the sleeve  10  has four concertina folds  11  of inside diameter preferably equal to or slightly greater than the diameter of the bushing  4 , so as to enable the concertina folds  11  to slide easily on the bushing  4 . Only the end wall of the last concertina folds has a diameter that is appropriate for enabling a force-fit on the bushing  4  so as to hold the sleeve  10  in place on the bushing  4 . 
         [0025]    At the end remote from the concertina folds, the resilient sleeve  10  has two pads  13 , having inside edges that define lips  14  that are urged towards each other by spring blades  15  embedded in the rubber forming the pads  13 . In the rest position shown in  FIG. 1 , the lips are rectilinear, forming a slot  16  that is closed in leaktight manner by the forces applied by the spring blades  15 . The spring blades  15  are subjected to prestress that is obtained in this first embodiment by providing a decreasing thickness E (see  FIG. 1 ) of material between a spring blade  15  and the corresponding lip  14  on going from the central zone of the spring blade towards its ends. The spring blades  15  are thus curved about an axis corresponding to the longitudinal axis of the sleeve  10 . The pads  13  also include clip-fastener studs  17  that are cantilevered out beyond the pads  13  and that are used for a purpose explained below. 
         [0026]    In the rest position, the wall portion  18  of the resilient sleeve that connects the pads  13  to the first concertina fold  11  takes on a pseudo-conical shapes as can be seen in  FIGS. 1 and 6 . 
         [0027]    When a force is applied to the ends of the pads  13 , as represented by bold arrows in  FIG. 1 , the spring blades  15  curve to a greater extent about the longitudinal axis of the resilient sleeve  10 , and the lips  14  separate, taking up a curve that becomes ever more pronounced until the sleeve is fully opened, as shown in  FIG. 2 . It is also possible to open the sleeve by exerting a force to separate the inside walls of the sleeve portion  18 , as explained below. 
         [0028]    In this position, the lips  14  are preferably semicircular in shape, so as to match the outline of the bushing  4  of the connector element  1 . For this purpose, and as shown in  FIG. 5 , the spring blades are preferably of width that decreases going from the central portions of the blades  15  towards their ends, in compliance with a sinusoidal relationship so as to obtain a return force that is constant at all points along the lips  14 . In order to avoid extra thickness at the ends of the diameter corresponding to the rest position of the lips  14 , the pads  13  preferably include flats  19  perpendicular to the slot  16 . These flats are folded in half (see  FIG. 4 ) when the sleeve is opened. 
         [0029]    The resilient sleeve  20  providing protection for the connector element  2  is of structure identical to that of the sleeve  10 , with the exception of the clip-fastener studs  17 , which are replaced by clip-fastener cavities  21 . Below, the same numerical references are given to portions that are identical, ignoring dimensions, given that the concertina folds  11  of the sleeve  20  have a diameter that matches the outside diameter of the bushing  7  of the connector element  2 . 
         [0030]    As shown in  FIG. 6 , when the connector elements  1  and  2  are separated, the sleeves  10  and  20  close in leaktight manner. When it is desired to engage the connector elements, the slots  16  of each of the sleeves  10 ,  20  are presented facing each other so that the clip-fastener studs  19  of the sleeve  10  face the clip-fastener cavities  21  of the sleeve  20 . Moving the connector elements towards each other causes the pads  13  to be clipped together so that they are subsequently secured to each other and therefore deform identically. Once the resilient sleeves  10  and  20  are clipped together, moving the connector elements  1  and  2  towards each other then causes the ends of the bushings  4  and  7  to bear against the corresponding inside faces of the sleeve portions  18 . The wall portions  18  then open progressively causing the lips  14  to move apart until the moment when the passage is large enough to allow the connection members  5  and  8  to engage mutually, as shown in  FIG. 8 . In this movement, the concertina folds flatten progressively as shown in  FIGS. 6 to 8 . The sleeve portions  18  are sufficiently rigid to ensure that the connection force causes them to slide over the bushings  4 ,  7  without folding. The inside surfaces of the sleeve portions  18  and the outside surfaces of the bushings  4 ,  7  preferably have coefficients of friction that facilitates mutual sliding. 
         [0031]    It should be observed that clipping the resilient sleeves  10  and  20  together serves not only to cause the lips  14  to open simultaneously, but also serves to pull each sleeve of the corresponding connector element when the connector elements are separated, thereby guaranteeing that the resilient sleeves return to the closed position when the connector elements are separated. 
         [0032]    It should be observed that only the front surfaces of the pads  13  are in danger of being covered in mud. By cleaning these front surfaces, it is possible to avoid any mud penetrating to the insides of the resilient protective sleeves  10  and  20 . 
         [0033]    In the second embodiment shown in  FIGS. 9 to 11 , the connector elements  1  and  2  are identical to those of the preceding figures, and they are therefore given the same numerical references. The protective sleeves  30  and  40  of the second embodiment no longer have concertina folds enabling the sleeves to be retracted as the connector elements move towards each other. In this embodiment, when the sleeve  40  surrounding the connector element  2  is in the open position, it constitutes a cylindrical sleeve having a wall of thickness that is constant, with the exception of an outwardly-directed chamfer at its end facing towards the corresponding end of the protective sleeve  30 . 
         [0034]    The sleeve  30  also has a wall that is cylindrical in the open position, but it further includes an inside shoulder  31  enabling the sleeve  40  to penetrate into the sleeve  30  during engagement of the connector elements  1  and  2 . The sleeve  30  also has a chamfer  32  at its end facing the sleeve  40 , the chamfer  32  facing inwards. As before, the protective sleeve  30  includes spring blades  33  that extend perpendicularly to the longitudinal direction of the resilient sleeves. However, in this embodiment, at rest, the spring blades  33  are rectilinear in planes parallel to the lips  14 , while being curved about an axis that is parallel to the spring blades, the curvature having its concave side directed towards the corresponding lip  14 . In order to obtain a regular circular shape for the lips  14  on opening the sleeves, the spring blades  33  are preferably analogous in shape in plan view to the spring blades  15  of the first embodiment. 
         [0035]    Given the interpenetration of the sleeves  30  and  40 , it is no longer possible to clip together the facing edges of the protective sleeves  30  and  40 . To encourage penetration when the ends of the sleeves  30  and  40  are pressed in engagement one against the other, the lips  14  in the closed position are now disposed in perpendicular planes as shown in  FIGS. 9 and 10 . Forces represented by bold arrows in  FIGS. 9 and 10  are exerted manually on the ends of the slots  16  to cause the sleeves  30  and  40  to open, with continued opening and penetration of the sleeves one in the other being facilitated by the chamfers  32  and  41 . 
         [0036]    The invention is not limited to the embodiments described, and various embodiments can be provided without going beyond the ambit of the invention as defined by the claims. 
         [0037]    In particular, although the springs  15  and  33  are shown as being in the form of two separate springs, they could be in the form of a one-piece ring, or they could be united by hinges at their ends. The sleeves of the invention can also be made without spring blades, by providing the sleeves with a flat shape when they are made, such that they are returned automatically thereto when in the rest position. 
         [0038]    Although the concertina folds in the first embodiment are shown as having identical inside and outside diameters, such that the sleeves are retracted by flattening the folds, it is possible to provide concertina folds of frustoconical shape so that the folds become engaged one within another during retraction. 
         [0039]    The number of folds need not necessarily be four. 
         [0040]    Although the invention is shown with reference to connector elements, each covered by a protective sleeve of the invention, it is possible to make provision for associating a protective sleeve of the invention with only one of the elements of the connector, e.g. the element connected to a cable, while the other connector element is protected in conventional manner, e.g. by a plug for the connector element that is mounted on the apparatus that is less likely to receive mud. 
         [0041]    To encourage sliding of the bushings relative to the sleeves, provision can be made to cover the contacting surfaces in polytetrafluoroethylene (PTFE) or the like. For this purpose, it is possible to use a PTFE tape that may also serve to stiffen the element on which it is fastened. 
         [0042]    In a variant, it is possible to provide localized stiffener elements (ribs, local reinforcement, whether fitted or integral, such as plates of material, a mesh or grid of ribs, . . . ), in particular on the sleeve portions  18 , in order to encourage the sleeve portions  18  to deform in a given direction (opening when making a connection). Conversely, zones of preferred deformation may be provided for the same purpose (such as zones of smaller thickness or non-through slots).