Patent Publication Number: US-9887494-B2

Title: Locking and unlocking system

Description:
RELATED APPLICATIONS 
     This application claims priority from French Patent Application No. 16 55043 filed Jun. 2, 2016, which is incorporated herein by reference in its entirety 
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates to a secure locking system that locks the system in place regardless of the vibrations of the exterior environment. 
     The invention also relates to an electrical connector and a connector assembly comprising such a locking system. 
     The invention can be applied in all fields where a housing needs to be locked onto another component. In particular, it can be applied in the area of connectors, and particularly connectors for the aeronautics or automotive industries, where connectors are subjected to high vibrations. 
     BACKGROUND OF THE INVENTION 
     In the area of connectors, a “connector assembly” is an assembly of two connecting elements (for example a male connecting element and a female connecting element) assembled to each other to make an electrical connection. Each of the connecting elements comprises one or more electrical contacts (male or female) suitable for assembly with the complementary electrical contacts of the other connecting element. 
     In some applications, particularly in the fields of aeronautics or automotive connectors, high environmental vibrations make the connecting elements move in relation to each other. These movements can lead to a loss of electrical bonding between said connecting elements within the same connector assembly. 
     In order to prevent the movement of a connecting element in relation to the other, fitting each connector assembly with a locking system for locking the link between the two connecting elements and thus preventing unintentional disconnection is known. Such a locking system must make it possible to maintain the connection, even when the connector assembly is subjected to vibrations. 
     To that end, the installation of a locking system around one of the connecting elements in order to lock each connecting element in relation to the other connecting element of the same connector assembly is known. Different locking systems are currently in existence. The best known system consists in a generally cylindrical locking ring mounted at the end of one of the connecting elements in order to hold the two connecting elements assembled. Said locking ring is generally a short hollow cylinder, henceforth called a ring, fitted with a first holding means intended to hold the ring free to rotate around a first connecting element and a second holding means intended to hold the ring on the second connecting element of the connector assembly. 
     Locking rings include locking rings where the second holding means is a thread for screwing said ring on the connecting elements, machined on the inner wall of the ring. 
     That thread is not always sufficient for maintaining the connection during vibrations, and so there are locking rings where the second holding means is supplemented by a series of notches intended to fit around a locking element. Those notches are also made in the inner wall of the ring, which has a series of notches intended to fit around a locking element. The locking element may then be a simple locking pin or a device that predominantly has a ball and a spring. In that second alternative, the locking element generally comprises a hole that opens out at the surface of the connecting element and forms a transverse recess. The locking element also comprises a spring placed transversally in the opening hole, that is to say placed perpendicular to the direction of the electrical contacts of the connecting element. That locking element additionally comprises a ball placed above the spring so as to be partly in the recess. That ball is positioned so as to be partly in the recess when the spring is relaxed and totally in the recess when the spring is compressed. In this alternative, the locking ring is mounted at the end of the connecting element so as to be able to cover the recess. 
     When the system is locked, the operator makes the locking ring rotate around the connecting element. The inner wall of the locking ring slides, notch after notch, around the end of the connecting element, and thus the locking element. Thus, the notched inner wall of the locking ring makes the ball move in its recess. That movement is brought about by the notches of the locking ring. That is because each notch has an asymmetrical tooth that is shaped substantially like a right-angled triangle. Each notch thus has a low lower side, and a higher upper side. The height of the upper side is substantially equal to the height of the part of the ball that projects out of the recess. Thus, when the locking ring is rotating, the lower side of the notches presses against the ball, compressing the spring. The ball is then entirely housed in the recess and does not project out of said recess. The locking ring continues to slide, and so the upper side of the notches is located opposite the ball, which can then move out of the recess in part as the spring relaxes. When the ball is partly out of its recess, it is locked in the notch of the locking ring, thus locking the connector assembly. 
     However, in extreme conditions, particularly with high vibrations or jolts, the spring can sometimes be compressed involuntarily, moving the ball into the recess, which allows the notches of the locking ring to slide and thus unlock said ring. Such extreme conditions occur, for example, in the field of automobiles, when a vehicle goes over a pothole or any other cavity in the road, or in the field of aeronautics, in air pockets or during landing impacts. 
     OBJECT AND SUMMARY OF THE INVENTION 
     This invention is aimed at remedying those drawbacks. 
     To that end, in a first aspect, this invention relates to a secure locking and unlocking system comprising:
         a plug body that is cylindrical in shape, which plug body comprises a threaded part on the outer wall,   a locking ring with a thread on the inside adapted to be mounted on the plug body, wherein said locking ring comprises at least one hole extending along a line parallel to the longitudinal axis of the locking ring and opening onto a locking surface, wherein said locking ring is configured to lock the locking system in one direction of rotation of the locking ring and unlock the locking system in the other direction of rotation of the locking ring,   a notched washer, one side of which is positioned on the locking surface of the locking ring,   a holding pin that locks the position of a locking element and is inserted in the hole extending beyond the locking surface,   an upper ring mounted on the locking ring, wherein the upper ring comprises a contact surface that is adapted to press against the other face of the notched washer, wherein said upper ring comprises a lever adapted to unlock the locking element in the direction of rotation of the locking ring,   the locking element, such as a latch, mounted on the holding pin to lock the position of the locking element, wherein said locking element comprises a flexible part adapted to fit between two notches of the notched washer,       

     remarkable in that:
         the locking ring comprises a groove, said groove is shaped like a ramp with a linear part, and then a rising ramp and a descending ramp,   a ramp spring ( 39 ) configured so that the locking or unlocking movement of the upper ring ( 28 ) is mobile and the locking ring ( 23 ) is fixed,   the upper ring comprises a hole in which a lug is placed, and the end of the lug cooperates with the ramp-shaped groove of the locking ring that guides the upper ring in relation to the locking ring.       

     Thanks to those arrangements, during extreme conditions, particularly high vibrations or jolts, the locking ring remains in place. That configuration prevents the locking element from passing several notches and prevents the unlocking of the ring. The number of parts is smaller than in the existing system, which reduces manufacturing costs. 
     The system makes it possible to lock the plug and prevent unwanted unlocking due to vibrations or pulling on the plug body. The manual rotation of the upper ring enables the user to unlock or lock it depending on the rotation direction. 
     That latch system makes it easy to manage the choice of locking or unlocking. Locking is by turning the upper ring clockwise. Unlocking is by turning the upper ring counterclockwise. 
     Thus, the operator feels the force applied on the locking ring and can sense the end of locking. In some environments, feeling the tightening and thus locking makes it possible to lock the system without seeing it. 
     Further, the plug remains within the size recommended by standard MIL-C 38999 SIII. 
     The invention can be implemented advantageously in the embodiments and alternatives described below, which may be considered individually or in any technically operative combination. 
     In one embodiment, the stiffness of the ramp spring applies a predetermined limit value for locking or unlocking the locking ring. 
     The spring is compressed and adds torque to locking and unlocking. That torque is greater than simple locking or unlocking. 
     In one embodiment, the predetermined limit value is above 0.2 Nm. 
     In one embodiment, the locking ring comprises a first visual mark and the upper ring comprises a second visual mark; when the first visual mark and second visual mark are lined up, the locking system is locked. 
     Thus the lining up or otherwise of the visual marks provides visual indication of whether or not the system is locked. 
     In one embodiment, a return spring is positioned in a recess of the upper ring between a guide pin and a support of the recess of the upper ring, wherein said spring is positioned in a circular manner in relation to the upper ring. 
     In one embodiment, the closing ring is held in place by a retaining circlip inside the upper ring. 
     In one embodiment, each notch of the notched washer has a vertical slope to block unlocking and an oblique slope to obtain a ratchet sound upon locking. 
     In one embodiment, the upper ring comprises an opening that lets through the plug body. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
       Other advantages, aims and characteristics of this invention will become apparent from the description below, which is explanatory and not limitative in any way, by reference to the drawings attached, wherein: 
         FIG. 1  is a perspective view of a secure locking system in a particular embodiment of the system according to this invention; 
         FIG. 2  represents a quarter-section perspective view of the locking system in  FIG. 1 ; 
         FIG. 3  is an exploded view of the secure locking system of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view along a plane perpendicular to the longitudinal axis of the locking system of  FIG. 1  in the locked position; 
         FIG. 5  is a cross-sectional view along a plane perpendicular to the longitudinal axis of the locking system of  FIG. 1  in the unlocked position; 
         FIGS. 6-9  represent another embodiment with a ramp; 
         FIGS. 10-24  represent locking of the embodiment shown in  FIGS. 6-9 ; 
         FIGS. 25-32  represent unlocking of the embodiment shown in  FIGS. 6-9 ; and 
         FIGS. 33-35  represent another embodiment with a visual mark. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION 
       FIG. 1  is a perspective view of a secure locking system according to a particular exemplary embodiment. The plug body  20 , the upper ring  28  and the locking ring  23  are visible. 
     The plug body  20  has a threaded part  21  on the outer wall. 
       FIG. 2  represents a quarter-section perspective view of the locking system in  FIG. 1 . The plug body  20 , the upper ring  28  and the locking ring  23  are also visible in this figure. 
     The closing ring  30  and the retaining circlip  33  (elastic ring) are also visible. 
     The closing ring  30  closes the locking system and prevents dust from entering inside the locking system. The retaining circlip  33  holds the closing ring  30  in its position. The closing ring  30  is positioned adjacent to the locking ring  23 . That is to say the closing ring  30  is set flat against the locking ring  23 . These two rings are concentric. 
     The upper ring  28  comprises an opening, referenced  34  (visible in  FIG. 3 ) that lets through the plug body  20 . This opening is cylindrical and circular. 
       FIG. 3  is an exploded view of the secure locking system of  FIG. 1 . 
     A plug body  20  that is cylindrical in shape can be seen. The plug body  20  comprises a threaded part  21  on the outer wall and another part comprising a series of notches  22 . The series of notches  22  represents a notched ring. 
     In one embodiment, the notched part  22  is added to the plug body  20  using a molding or heading process. 
     A locking ring  23  that is threaded on the inside and suitable for being mounted on the plug body  20  is visible. The locking ring  23  comprises at least two holes  24 . Each hole  24  extends along a line parallel to the longitudinal axis of the locking ring  23  opening onto a locking surface. 
     The locking ring  23  is configured to lock the locking system in a direction of rotation of the locking ring  23  and to unlock the locking system in the other direction of rotation of the locking ring  23 . 
     In this exemplary embodiment, there are two holding pins  25  to lock the position of a locking element  27 . The two holding pins  25  are inserted in two adjacent holes  24 . These holes  24  extend beyond the locking surface. 
     In this exemplary embodiment, there are four guide pins inserted in other holes  24 . These holes  24  also extend beyond the locking surface. 
     The upper ring  28  is mounted on the locking ring  23 . The upper ring  28  is placed on top of the locking ring  23 . 
     On that plug body  20 , the threaded locking ring  23  is mounted before the notched ring. 
     The upper ring  28  comprises a contact surface suitable for pressing against the locking surface of the locking ring  23 . 
     The contact surface comprises four oblong through holes  29  adapted to receive the guide pin  26 . The shape of the oblong holes allows a degree of freedom and leaves room for the locking ring  23  to move slightly in a concentric manner in relation to the plug body  20 . The oblong holes are located so as to follow the rotation of the locking ring  23 . 
     The upper ring  28  comprises a flexible part  31  that is adapted to unlock the locking element in the direction of rotation of the locking ring  23 . The flexible part  31  is an arm with a circular shape located inside the upper ring  28 , which follows the circular shape of the upper ring  28 . 
     The locking element  27 , such as a latch, is mounted on the two retaining pins  25  that block the position of the locking element  27 . The locking element  27 , henceforth called latch, comprises a flexible part adapted to fit between two notches of the plug body  20 . The part is flexible thanks to the elasticity of the material. 
     The use of a latch blocks the unlocking of the plug body  20  brought on by parasite vibrations. The latch is manually disengaged by rotating the upper ring  28  that is on top of the locking ring  23  containing the thread engaged with the thread of the plug body  20 . 
     In the stable position, the latch is pressed against the notches, which blocks any involuntary unlocking. 
     In order to unlock the connector, the operator must turn the upper ring  28  by about 10° in the counterclockwise direction. 
     As a result, the flexible part of the upper ring  28  (or arm) located at the perimeter of the notches lifts the latch. The connector is thus unlocked. 
     The upper ring  28  is set against four pins inserted in the locking ring  23 , and the user only needs to continue turning in the counterclockwise direction to unlock the connector entirely. A return to a stable position with a latch engaged with the notches of the plug body  20  is made possible thanks to a return spring  32  placed in the tangential position of the locking ring  23 . 
     The return spring  32  is placed in a housing of the upper ring  28  between a guiding pin  27  and a support of the recess of the upper ring  28 . The return spring  32  is placed in a circular manner in relation to the upper ring  28 . 
       FIG. 4  is a cross-sectional view along a plane perpendicular to the longitudinal axis of the locking system of  FIG. 1  in the locked position. 
     In that configuration, the guide pins  26  are positioned to the right of the oblong through holes  29 . 
     The arrow shows the locking direction. The dotted circle shows the locking location. 
       FIG. 5  is a cross-sectional view along a plane perpendicular to the longitudinal axis of the locking system of  FIG. 1  in the unlocked position. 
     In that configuration, the guide pins  26  are positioned to the left of the oblong through holes  29 . 
     The flexible part  31  is adapted to unlock the latch in the direction of rotation of the locking ring  23 . The flexible part is used to lift the latch. 
     The arrow shows the unlocking direction. The dotted circle shows the unlocking location. 
       FIG. 6  shows another embodiment with a ramp. This figure shows the plug body  20 , the locking ring  23 , the upper ring  28 , the flexible part  31  and the notched washer. 
     In an unillustrated alternative, there is only a ramp spring, referenced  39  in the figure, which makes it possible to make the upper ring  28  mobile during the locking or unlocking phase: the locking ring  23  is fixed and the upper ring  28  is mobile via the ramp spring  39 . 
     In the illustrated alternative, a first ramp spring  38  is placed between the plug body  20  and the locking ring  23 . A second ramp spring  39  is placed between the plug body  20  and the upper ring  28 . 
     The stiffness of the first spring and second spring applies a predetermined limit value for locking or unlocking the locking ring  23 . Thus, the operator feels the force applied on the locking ring and can sense the end of locking. In some environments, feeling the tightening and thus locking makes it possible to lock the system without seeing it. 
       FIG. 7  is an exploded view of the secure locking system of  FIG. 6 . 
     A plug body  20  that is cylindrical in shape can be seen. The plug body  20  has a threaded part  21  on the outer wall. 
     A notched washer  37 , one side of which is positioned on the locking surface of the locking ring, can be seen. 
     A locking ring  23  that is threaded on the inside and adapted to be mounted on the plug body  20  is visible. The locking ring  23  comprises at least one hole  24 . The hole  24  extends along a line parallel to the longitudinal axis of the locking ring  23  opening onto a locking surface. In this embodiment, there are two holes  24 . 
     The locking ring  23  is configured to lock the locking system in a direction of rotation of the locking ring  23  and to unlock the locking system in the other direction of rotation of the locking ring  23 . 
     In this exemplary embodiment, there are two holding pins  25  to lock the position of a locking element  27 . The two holding pins  25  are inserted in two adjacent holes  24 . These holes  24  extend beyond the locking surface. 
     The upper ring  28  is mounted on the locking ring  23 . The upper ring  28  is placed on top of the locking ring  23 . 
     On that plug body  20 , the threaded locking ring  23  is mounted before the notched ring  37 . 
     The upper ring  28  comprises a contact surface  42 , shown in the next figure, adapted to press against the other side of the notched washer  37 . 
     The contact surface  42  comprises a lever  41 . 
     The closing ring  30 , the opening  34  and the circlip have been described above. 
     The locking ring  23  moves in a concentric manner in relation to the plug body  20 . 
     The locking ring  23  comprises a through hole, and said hole is shaped like a ramp  36  with a linear part, and then a rising ramp and a descending ramp. 
     The upper ring  28  comprises a through hole in which a lug  35  is placed, and the end of the lug  35  cooperates with the ramp-shaped through hole of the locking ring  23  to guide the upper ring  28  in relation to the locking ring  23 . 
     The upper ring  28  comprises a flexible part  31  that is adapted to unlock the locking element in the direction of rotation of the locking ring  23 . The flexible part  31  is an arm with a circular shape located inside the upper ring  28 , which follows the circular shape of the upper ring  28 . 
     The locking element  27 , such as a latch, is mounted on the two retaining pins  25  that block the position of the locking element  27 . The locking element  27 , henceforth called latch, comprises a flexible part adapted to fit between two notches of the plug body  20 . The part is flexible thanks to the elasticity of the material. 
     The use of a latch blocks the unlocking of the plug body  20  brought on by parasite vibrations. The latch is disengaged by the lever  41  (shown in the next figure), manually by rotating the upper ring  28  that is on top of the locking ring  23  containing the thread engaged with the thread of the plug body  20 . 
     In the stable position, the latch is pressed against the notches, which blocks any involuntary unlocking. 
     In order to unlock the connector, the operator must turn the upper ring  28  by about 10° in the counterclockwise direction. 
     As a result, the flexible part of the upper ring  28  (or arm) located at the perimeter of the notches lifts the latch. The connector is thus unlocked. The user only has to continue turning in the counterclockwise direction to unlock the connector entirely. 
     The working of the first ramp spring  38  and the second ramp spring  39  has been explained above. 
       FIG. 8  shows some of the elements of  FIG. 7  once again. This figure shows the contact surface  42  and the lever  41 , as described above. 
       FIG. 9  shows the locking element  27 , the flexible part  31  and the notched washer  37 . 
       FIGS. 10 to 24  represent locking of the embodiment shown in  FIGS. 6 to 9 . These figures show the locking ring  23 , the flexible part  31 , the upper ring  28 , the first ramp spring  38 , the second ramp spring  39 , the plug body  20 , the notched washer  37 , the lug  35 , the ramp  36 , the notch of the flexible part  40  and the lever  41 . 
       FIGS. 10 to 12  show the plug body  20  in the free state. The locking ring  23  and the upper ring  28  can only turn clockwise in relation to the plug body  20 . That is because of the particular profile of the notches of the notched washer  37  and the notch of the flexible part  40 . 
       FIGS. 13 to 15  show another position. 
     During screwing onto the plug body  20 : first, when the tightening torque has not reached a predetermined limit value imposed by the standard (Cv min), the locking ring  23  and the upper ring  28  are integral with each other, because of the position of the lug  35  along the profile of the ramp  36 . Rotating the upper ring  28  makes the plug body  20  rotate. 
       FIGS. 16 to 18  show another position. 
     While screwing onto the base socket: when the end of the socket  43  comes into contact with the plug body  20 . The tightening torque stiffens without reaching Cv min, the rotation of the upper ring  28  separates from that of the locking ring  23 . The locking ring  23  continues to be screwed to the socket  43 , and the first ramp spring  38  is compressed. The upper ring  28  moves back in relation to the locking ring  23 . 
       FIGS. 19 to 21  show another position. 
     When the locking ring  23  reaches the extreme position with the plug body  20 , the tightening torque stiffens to exceed Cv min. Then the locking ring  23  ceases to turn and the upper ring  28  continues to turn alone, the lug  35  passes the top of the ramp  36  (peak tightening torque) and moves the upper ring  28  back furthest from the locking ring  23 . 
       FIGS. 22 to 24  show another position. 
     The tightening torque of the upper ring  28  then decreases, till it increases again when the tightening ring  23  and the upper ring  28  are integral once again. The operator stops turning the upper ring  28 . The plug body  20  is locked with socket  43 . The stable position of the lug  35  in the hollow of the ramp  36  by the thrust of the second ramp spring  39  on the upper ring  28  guarantees the locking of the plug body  20 . Unlocking the plug body  20  makes it necessary for the operator to take manual action. 
       FIGS. 25 and 26  show another position. 
     To unlock, the operator must apply torque in the counterclockwise direction in a value above the minimum unlocking torque imposed by the standard. The upper ring  28  separates from the locking ring  23 , the lug  35  then moves down the ramp  36  following its profile. The locking ring  23  remains locked on the socket  43  because the flexible part  31  is not lifted. 
       FIGS. 27 to 29  show another position. 
     The lever  41  ultimately reaches the extreme position with the flexible part  31 . The first ramp spring  38  is then at maximum compression. 
       FIGS. 30 to 32  show another position. 
     The operator continues to turn the upper ring  28  to unlock the plug body  20 . The flexible part  31  is then lifted. The upper ring  28  becomes integral with the locking ring  23  once again when the lug  35  reaches the extreme position at the bottom of the ramp  36 . The socket  43  is then unlocked. 
       FIGS. 33, 34 and 35  represent another embodiment with a visual mark. 
     These figures show visual indication of locking and unlocking, achieved by the lining up or otherwise of the visual marks placed opposite each other between the locking ring  23  and the upper ring  28 . These visual marks are represented by circles and are colored. There are three cases of correspondence:
         in the first case, the mark is fully red, showing that the plug is securely locked;   in the second case, the mark is a blue circle surrounded by a red collar, showing that the plug is not locked;   in the third case, the mark is a green circle surrounded by a red collar, showing that the plug is being unlocked.       

     In an alternative that has not been illustrated, the flexible part comprises a spring that forces the flexible part to move by blocking or not the notches of the notched ring  37  or the notches of the plug body  20 . 
     LIST OF PARTS 
     
         
           20  plug body 
           21  threaded part 
           22  notches 
           23  locking ring 
           24  holes 
           25  retaining pin 
           26  guide pin 
           27  locking element 
           28  upper ring 
           29  oblong through hole 
           30  closing ring 
           31  flexible part 
           32  return spring 
           33  retention circlip 
           34  opening 
           35  lug 
           36  ramp 
           37  notched washer 
           38  first ramp spring 
           39  second ramp spring 
           40  notch of flexible part 
           41  lever 
           42  contact surface 
           43  base