Abstract:
A locking connector system includes a first body having a rotatable collar mounted thereon and a second body configured to mate with the first body, including one or more components configured to control the breakaway force of the first and second bodies. The first and second bodies include telescopingly engaged body portions and axially mating contacts. The connector system further includes an annular collar encircling the telescoping body portions and rotatively held on the first body and a spring inside the collar. The ends of the spring are confined between the first body and the collar so as yieldingly to resist rotation of the collar relative to the first body. Axially aligned tabs are provided on the collar and the second body for latching the first body and the second body together through a predetermined range of forces. The tabs include opposed flaring cam surfaces, which cause the collar to rotate relative to the second body as the first and second body are telescoped to a mated contact position and at least one tab includes an angled back surface. The cam surfaces guide the collar tab around the body tab, and the coiled spring yields as the collar is rotated by the cam tabs during contact mating to allow the collar tab to slide past the body tab. The spring then rotates the collar tab to a latching position axially behind the body tab, thereby locking the connector bodies in mated contact position.

Description:
RELATED APPLICATIONS  
       [0001]     The present invention is a continuation-in-part of U.S. patent application Ser. No. 10/202,514, filed Jul. 23, 2002, the contents of which are herein incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to an automatically locking connector system for joining a first connector body with a second connector body.  
       BACKGROUND OF THE INVENTION  
       [0003]     Automatically locking connector systems are used for a variety of applications, such as electrical, fluidic, mechanical, optical, hydraulic or pneumatic systems, to provide a connection between various components and devices. A typical connector may comprise a female connector assembly and a male connector assembly that are designed to be engaged and disengaged with one another. Prior patents describe a coupling mechanism, having one coupler half that is inserted into the other half and a sleeve on one half, which rotates against a torsional spring force as a result of the camming action of complementary triangularly-shaped tabs on the sleeve and the inserted coupler half. The restoring force of the spring causes the sleeve to rotate into a locking position after the complementary tabs have passed each other. The tabs prevent disengagement of the coupler halves until the sleeve is twisted to permit the tabs to clear each other during uncoupling. For example, U.S. Pat. Nos. 5,067,909, 5,167,522 and 5,662,488, all of which are incorporated herein by reference, describe automatically locking couplers, in which a locking sleeve is rotated against a spring force during initial insertion of one coupler half into the other, and permitted to rotate back into a locking position upon completion of insertion.  
         [0004]     With telescopically mating electrical connectors, such as a plug and a socket, it is often desirable or necessary to lock the two connector bodies together after their conductive contacts have been physically and electrically joined. Single conductor connectors with some form of bayonet joint may be rotated to a locking position. Multiple male and female contacts, however, must be slidingly joined telescopically without rotation, and typically have used a pliable plastic connector body which is deformed as a catch on one connector body rides over a detent on the other connector body to a locking position beyond the detent. If such a deforming latching body is frequently engaged and disengaged, the plastic tends to fatigue from the deformation. As a result, the latching mechanism eventually fails. In addition, care must be taken during assembly of the connector to ensure that the connectors fully engage with each other.  
         [0005]     Most locking connectors are designed to lock in the mated position and must be manually disengaged. In certain applications, it is desirable that the connectors automatically disconnect when a force exceeding a predetermined level is applied to the connector assembly or a cable extending from the connector assembly. For example, requirements exist in some industries that a mated pair of connectors disengage (or break away) before the cable is damaged, the connector pair is damaged, personnel trip over the cord, electrodes connected to the connector are stripped off a patient (in medical applications) and/or attached equipment, such as an electronic device, falls and becomes damaged, falls from a shelf and crashes to the floor or falls in such a way to cause personal injury.  
         [0006]     It may also be desirable to reinforce the connector to prevent accidental disengagement of the connector pair.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides a reinforced locking connector. The present invention combines a self-latching arrangement with a manual de-coupling arrangement in a connector system. The locking connector comprises first and second tubular connector bodies having telescopingly engaged body portions and axially mating contacts, an annular collar rotatively held on the first body encircling the telescoping body portions and a spring inside the collar. The ends of the spring are confined between the first body and the collar so as to yieldingly resist rotation of the collar relative to the first body. Axially aligned tabs are provided on the collar and the second body for latching the first body and the second body together through a predetermined range of forces. The tabs include opposed flaring cam surfaces, which cause the collar to rotate relative to the second body as the first and second body are telescoped to a mated contact position. The cam surfaces guide the collar tab around the body tab, and the coiled spring yields as the collar is rotated by the cam tabs during contact mating to allow the collar tab to slide past the body tab. The spring then rotates the collar tab to a latching position axially behind the body tab, thereby locking the connector bodies in mated contact position. The collar tab and the cam tab are configured to reinforce the connection between the first body and the second body to prevent accidental disconnection of the first and second bodies. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0008]      FIG. 1  is an exploded isometric view of a connector system according to an illustrative embodiment of the invention with first and second connector bodies and a collar;  
         [0009]      FIG. 2  is an exploded side view, of the first body, collar and second body of the connector system according to an illustrative embodiment of the invention;  
         [0010]      FIG. 3  is an enlarged view of the second body, illustrating in detail the configuration of the camming tab.  
         [0011]      FIG. 4  is an end elevation view of the first body viewed from a plane X-X between the collar and second body.  
         [0012]      FIG. 5  is an end elevation view of the collar viewed from a plane X-X between the collar and second body.  
         [0013]      FIG. 6  is an end elevation view of the second body viewed from a plane X-X between the collar and second body;  
         [0014]      FIG. 7  illustrates a section on line  7 - 7  of  FIG. 2  of the connector system.  
         [0015]      FIGS. 8   a  and  8   b  illustrate the second connector body according to an alternate embodiment of the invention.  
         [0016]      FIG. 9  illustrates an alternate embodiment of the second body, wherein the camming tab is angled in a opposite direction to the camming tab of  FIG. 3  to increase the breakaway force.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     The present invention provides a self-latching connector system including one or more components configured to control the breakaway force of the connector system. The invention will be described below relative to illustrative embodiments. Those skilled in the art will appreciate that the present invention may be implemented in a number of different applications and embodiments and is not specifically limited in its application to the particular embodiments depicted herein.  
         [0018]      FIG. 1  illustrates a locking connector  10  according to an illustrative embodiment of the invention. According to the illustrative embodiment, the connector  10  is used in an electrical application, though one skilled in the art will recognize that the connector can be implemented in any suitable system. The connector  10  comprises a first connector body or plug  20  and a second connector body or receptacle  30  configured to receive and/or engage the first connector body  20 . According to the illustrative embodiment the first connector body  20  is a male connector having a cylindrical shaped housing with male contacts  22  enclosed in recesses  23  of an insulative boss  24 . The illustrative second connector body  30  is a female connector having a cylindrical shaped housing defining a cavity  34  for receiving the boss  26 . The second body further includes female contacts  32  disposed in the cavity  34  for mating with the male contacts  22  of the first connector  20 . The plug boss  24  telescopes into the cavity  34  of the second connector body or receptacle  30 , such that the male contacts  22  axially mate with the female contacts  32  when the first body  20  engages the second body  30  along the longitudinal axis A-A. The second body may further include a flange  29  and threads  31  for mounting the second body in a panel with a nut or other suitable mating device.  
         [0019]     An annular collar  40  is rotatably mounted on the first connector body  10  to latch the connector bodies  20 ,  30  together. When the two bodies are mated, the annular collar  40  encircles the boss  24  of the first body and the socket  34  of the second body to hold the connector bodies together. According to the illustrative embodiment, the collar  40  includes one or more internal radial stops  42  and the first connector body includes a first flange  110  having one or more passageways  120  extending longitudinally and configured to receive the stops  42  on the collar  40 . An annular groove  130  is also formed on the first connector body  20  for receiving the internal radial stops  42  of the collar.  
         [0020]     The collar  40  is mounted to the first body  20  by sliding the collar  40  along the longitudinal axis A-A over the boss  24 , such that the internal radial stops  42  on the collar  40  are admitted through the passageways  120  on the first body and into the annular groove  130 . The annular groove  130  axially confines the stops and holds the collar  40  rotatively around the first body  10 . The stops limit the amount of rotation of the collar to a range of about forty degrees. One skilled in the art will recognize that other suitable means of rotatably locking the annular collar  40  to the first connector body  20  may be used in accordance with the teachings of the invention.  
         [0021]     The collar further includes at least one camming tab  210  configured to engage one or more camming tabs  220  on the second body to lock the connector bodies together. According to the illustrative embodiment, the camming tabs  210 ,  220  comprise opposing, pie-shaped protrusions, though other configurations may be used according to the present invention. The camming tabs  210 ,  220  comprise opposing points  331 ,  332 , respectively, and two camming surfaces  341 ,  342 , respectively, flaring away from each point to intersection with a back surface  361 ,  362 , respectively.  
         [0022]     According to the illustrative embodiment, one or more of the back surfaces  361 ,  362 , preferably the back surface  362  on the second connector  30 , is angled relative to a radial axis B-B that extends along the direction of rotation of the collar and perpendicular to the longitudinal axis A-A, as shown in detail in  FIG. 3  to facilitate automatic release of the connector bodies when a predetermined force is applied to the connector system. The angled back surface  362  of the receptacle tab contrasts the camming tabs described in U.S. Pat. Nos. 5,067,909, 5,167,522 and 5,662,488, which extend in the direction of rotation of the collar, perpendicular to the longitudinal axis A-A. As shown, the back surface  362  is inclined from the radial axis B-B to form a ramp that extends at a forward angle, i.e., in a direction that is axially and radially forward relative to a back point  335  of the camming tab  220 . As used herein, “radially” refers to the direction of rotation of the collar, axis B-B, and “axially” refers to the direction of the axis A-A, i.e. along the longitudinal axis of the connector system. “Radially forward” refers to the direction of rotation of the collar indicated by the marker  300  on the collar, i.e., toward the ramp  370  from the tab  220 . “Axially forward” refers to the direction of movement of the first body relative to the second body during disengagement. “Radially backward” refers to a direction opposite the radially forward direction and “axially backward” refers to the direction opposite the axially forward direction, i.e., the direction of movement of the first body relative to the second body during engagement. According to an illustrative embodiment, the back surface of the receptacle camming tab extends at an angle θ, relative to the line B-B, as shown in  FIG. 3 , and relative to the back surface of the camming tabs described in U.S. Pat. No. 5,067,909. In the embodiment shown in  FIG. 3 , the angle θ extends between about 5 degrees and about 45 degrees in the axially forward direction. The operation of the camming tabs will be described in detail below.  
         [0023]     A coiled spring  47  may be provided for biasing the collar  40  into a normal position when the collar is mounted on the first connector body  20 . The coiled spring  47 , illustrated as a round wire of spring metal, though any suitable mechanism for biasing the collar may be used, is also confined in the annular groove  130  of the first body  20 . The spring  47  may be anchored at a first end inside the collar at a first stop  142  (shown in  FIG. 5 ) and at a second end in a small recess  138  in the groove  130 . As shown in  FIG. 6 , the spring  47  is biased yieldingly to constantly urge the collar stops  42  to a normal position abutting the opposed stops  190  in the groove  130 . In the rest position, as described in detail below, the camming tabs  210  provided on the collar  40  are located relative to the male contacts  22  of the first body such that the collar camming tabs  210  and male contacts  22  are in matching alignment with corresponding camming tabs  220  on the second body  20  and the female contacts  32  on the second body  20 , respectively.  
         [0024]     The insulative boss  24  of the first connector body  10  further includes longitudinal keyways  260  and  270 , which receive keys  230  and  240  formed on an inner surface of the receptacle cavity on the corresponding female connector to assure correct angular alignment during mating engagement. The keys may comprise a relatively narrow key  230  and a relatively wide key  240  and the keyways may comprise a relatively narrow keyway  260  for receiving the narrow key  230  and a relatively wide keyway  270  for receiving the wide key  240 . The keys and keyways are arranged such that when the first connector body  20  and the second connector body  30  are engaged (i.e. the keys are inserted in the corresponding keyways), the collar camming tabs  210  have substantially the same angular relationship to the male contacts as the receptacle camming tabs have to the female contacts when the collar is in the rest position.  
         [0025]     Index marks may also be provided as a visual aid to the correct angular alignment in alignment of the bodies  20 ,  30 . For example, the illustrative connector system includes a first index mark  290  on the collar, a second index mark  280  on the first body and a third index mark  310  on the second body, which align when the connector bodies are properly engaged. The mark  290  on the collar may further include an arrowhead  300  indicating the direction in which the collar  40  can be rotated from the normal position during the two operations of locking engagement and disengagement of the two bodies.  
         [0026]     To lock the male and female connector together, the markers  290 ,  310  on the collar  40  and the female connector  30 , respectively, are manually aligned and the two bodies are pushed together along the longitudinal axis A-A to achieve a snap-lock. When the bodies are pushed together, the second body  30  receives the first body  10 , as the boss  24  telescopes in the cavity  34  and the keys  230 ,  240  slide into the keyways  260 ,  270 , respectively. At the same time, the camming tabs  210 ,  220  slide past each other. The collar camming tab  210  is offset a small angle from a central plane through the collar and receptacle to facilitate engagement. After first sliding engagement, the mutual edging action of the camming surfaces  341 ,  342  forces the collar  40  to rotate against the spring, i.e., in the radially backward direction, allowing the collar tab  210  to slide around the receptacle tab  220  and then spring back with its back surface  361  behind the back surface  362  of the receptacle tab  220 .  
         [0027]     In this position, the tabs lock the first body  20  to the second body  30  through a predetermined range of forces. The spring  47  reverses rotation of the collar  40  until the faces of the collar stops strike the opposed faces of the plug stops. An audible “snap” signals that the first body  20 , the plug, and the second body  30 , the receptacle, are locked together. Locking may be visually confirmed by alignment of the index marks after the automatic return of the collar to its normal position by the spring. The camming tabs  210 ,  220  are configured to provide automatic release when a predetermined force is applied to one or both of the bodies.  
         [0028]     The connectors may be released manually, by rotating the collar  40  in the radially forward direction, or by applying a predetermined breakaway force to the connectors along the longitudinal axis A-A. To disengage the connectors, the collar  40  is manually rotated in the radially forward direction, as indicated by the arrowhead  300 . The rotation of the collar  40  in the radially forward direction turns the collar camming tabs  210  towards a circumferential ramp  370  slanting across the paths of the tabs. The camming face of each ramp is angled away from the adjacent tab, so that it cams the collar tab  210 , collar  40  and first body  20  apart and out of engagement with the second body  30 . In this manner, disengagement can be effected without pulling and straining the cord extending from the plug, because the rotation of the collar is in a plane at right angles to the axis of the plug and cord.  
         [0029]     The camming tabs are also configured to automatically disengage upon application of a predetermined breakaway force to either of the connector bodies. For example, as shown, the back surface  362  of the receptacle camming tab is angled relative to the direction of rotation of the collar  40  to provide automatic release upon application of a force along the longitudinal axis A-A that exceeds a predetermined value. The predetermined breakaway force is inversely proportional to the angle of the back surface of the receptacle camming tab relative to the line B-B. According to the illustrative embodiment, the back surface  362  of the receptacle camming tab  220  is angled about 10 degrees, as shown in  FIG. 3 , to enable automatic disengagement of the connector upon application of a force that exceeds the predetermined breakaway force. According to the illustrative embodiment, the predetermined breakaway force is between about one pound and about twenty pounds and preferably about ten pounds for the illustrated angle θ. When a pulling force larger than about the predetermined breakaway force is applied, the sloping back surface allows the collar camming tab  210  to slide past the receptacle camming tab  220 , releasing the connection without damaging the connector components and/or before damage to equipment or persons occurs. In contrast, the camming tabs described in the prior art have back surfaces which are substantially perpendicular to the longitudinal direction along axis A-A, which prevent the tabs from sliding past each other when a pulling force is applied along the longitudinal axis.  
         [0030]     According to an alternate embodiment, a receptacle body  30 ′ of the locking connector pair includes engagement recesses  300  formed in the exterior of a cavity  34 ′, as shown in  FIGS. 8   a  and  8   b , in place of the camming tab and circumferential ramp. The engagement recesses  300  are configured to engage with the collar camming tabs  210  to temporarily lock the collar to the second body. Each engagement recess  300  includes a ramped wall  370 ′ corresponding to the circumferential ramp  370  of the receptacle  30  of  FIGS. 1-9 , a longitudinal wall  380  and a protrusion  220 ′ forming a camming tab extending from the longitudinal wall  380 . As shown, the protrusion includes a back wall  210   a  extending axially and radially forward from the longitudinal wall  380  at a predetermined angle relative to the line B-B and a camming wall  210   b  forming a camming surface for allowing the collar tab to slide past the protrusion  220 ′ when slid along the longitudinal axis. The longitudinal wall  380  and the protrusion form a recess slot located axially behind the protrusion  220 ′ for retaining the collar camming tab when the receptacle body  30 ′ is engaged with the first plug body  20 . As described above, the back wall  210   a  is angled by a selected amount to provide automatic release of the collar camming tab when a predetermined force is applied to the connector bodies.  
         [0031]     According to another embodiment of the invention, the connector may be configured to increase the breakaway force between the first and second connector bodies, thereby reinforcing the connection between the first and second connector bodies. For example, as shown in  FIG. 9 , one or more of the back surfaces  361 ″,  362 ″, preferably the back surface  362 ″ on the camming tab  220 ″ of the second connector  30 ″, is angled relative to a radial axis B-B that extends along the direction of rotation of the collar and to the longitudinal axis A-A, as shown in detail in  FIG. 9 , to increase the breakaway force the first and second connector. As shown, the angled back surface  362 ″ of the receptacle tab extends in an inverse direction relative to the back surface  362  of the receptacle tab  220  of  FIG. 3 . As shown, the back surface  362 ″ of the reinforcing tab  220 ″ is inclined from the radial axis B-B to form a ramp that extends at a negative angle −θ, i.e., in a direction that is axially backward and radially forward from a back point  335 ″ of the camming tab  220 ″. According to the illustrative embodiment, the back surface  362 ″ of the receptacle camming tab extends at an angle −θ to reinforce the connection between the bodies by urging an engaged collar camming tab  210  in the radially backward direction, away from the ramp  370 . The configuration of the back surface  362 ″ thus inhibits sliding of the collar tab  210  toward the ramp, thereby preventing release of the collar tab  210  from the camming tab  220 ″ of the second connector  30 ″. According to the illustrative embodiment, the angle −θ is between about 5 degrees and about 45 degrees relative to the line B-B, as shown in  FIG. 3 , and relative to the back surface of the camming tabs described in U.S. Pat. No. 5,067,909. One skilled in the art will recognize that the connector may have any suitable configuration for modifying the breakaway force between the first body and the second body.  
         [0032]     The reinforced locking connector second connector body  30 ″ may alternatively include an engagement recess, corresponding to the engagement recess  300  shown in  FIGS. 8A and 8B , including a protrusion, corresponding to the protrusion  220 ′, having a back wall extending at a negative angle from a longitudinal wall. The reverse orientation of the back wall serves to prevent premature release of the connector bodies.  
         [0033]     As described above, the back wall of a camming tab of a locking connector according to the present invention may extend at a forward angle relative to the radial axis B-B to decrease the breakaway force and allow for quick release of the connector bodies. Alternatively, the back wall may extend at a negative angle relative to the radial axis B-B to increase the breakaway force and prevent release of the connector bodies.  
         [0034]     One skilled in the art will recognize that the correlation between the angle of the back wall and the breakaway force depends on the type of material and properties of the material used to form the connector bodies. For example, for materials having a higher coefficient of friction, a relatively larger angle may correspond to a selected breakaway force, while materials having a lower coefficient of friction require a relatively smaller angle to obtain the selected breakaway force. According to the illustrative embodiment, the angle of the back wall of the receptacle camming tab is between about 5 and about 45 degrees relative to the radial axis B-B, in either direction, and the predetermined breakaway force is between about one and about forty pounds, depending on the configuration of the back surface of the camming tab, though one skilled in the art will recognize any suitable angle and breakaway force may be used in accordance with the present invention. One of ordinary skill in the art will be able to determine a suitable angle to provide a desired breakaway force in a connector system of the invention.  
         [0035]     Furthermore, one skilled in the art will recognize that alternatively the collar may alternatively be mounted on the female connector and camming tabs may be provided on the male connector.  
         [0036]     One skilled in the art will recognize that the invention is not limited to the illustrative automatic release mechanism and that other means of providing an automatic release mechanism may be used according to the teachings of the invention.  
         [0037]     The rotating collar and camming tabs of the connector provide automatic locking engagement of the plug and socket without deformation of the plastic, insulative connector bodies or collar. Engagement is indicated positively by an audible snap and by alignment of index marks. The spring allows a rotary disengaging manipulation, which is convenient and which places no longitudinal strain on a cord or cable connected to the plug body. The connectors provide a secure connection up until a predetermined breakaway force and further allow automatic de-coupling of the connector system to prevent injury, damage to the connector bodies, damage to the cords attached to the connector bodies and/or damage to components attached to the connector bodies. The connector pair can be reused even after the bodies have been separated by the application of the predetermined force. The breakaway force can be modified by changing the angle of the back wall of the receptacle camming tab. Moreover, a receptacle body having a modified camming tab to allow for the automatic de-coupling can be used with current plug bodies, such as the male connector of the PULSE-LOK from Alden Products, described in U.S. Pat. No. 5,067,909 without requiring modification of the plug body. In this manner, a connector system can be easily converted to provide automatic de-coupling at a predetermined without requiring replacement of all of the components of the system.  
         [0038]     The present invention has been described relative to an illustrative embodiment. Since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. It should be understood that the present disclosure is for the purpose of illustration only, and that the invention includes all modifications and equivalents falling within the appended claims  
         [0039]     It is also to be understood that the following claims are to cover all generic and specific features of the invention described herein, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.  
         [0040]     Having described the invention, what is claimed as new and protected by Letters Patent is: