Patent Publication Number: US-7722374-B2

Title: Hermaphroditic coupling with rotational engagement and flexible interlock

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a Continuation of U.S. patent application Ser. No. 11/775,177 filed Jul. 9, 2007, issued as U.S. Pat. No. 7,549,883 on 23 Jun. 2009, which claims priority to related provisional patent application, Ser. No. 60/819,418filed Jul. 7, 2006, which is not admitted to be prior art with respect to the present invention by its mention in the background. This application is incorporated herein by this reference. 

   BACKGROUND 
   The invention relates to an improved coupling, specifically a simple, genderless device to provide mechanical, electrical or optical connection between two components without the need for separate and dissimilar male and female connectors. 
   Devices to connect two components, either mechanically, electrically, optically or all three exist in numerous varieties. These connecting devices can be broadly divided into two categories: gendered and genderless. 
   Gendered couplings consist of two dissimilar but complementary connectors that fit together to create a continuous, connected signal or structural pathway to provide mechanical connection or to support transmission of power or data signals, including digital, analog, optical and electrical. Gendered couplings take the form of male and female connectors, where a first probe mates with a corresponding receptacle. Examples of gendered couplings include USB connectors, RCA audio jacks, Ethernet jacks, and power plugs, among many others. By virtue of their design, gendered couplings require dissimilar connectors and frequently, connection in a specific orientation. A well-known connector for power cables is the standard plug and receptacle. When stringing together such items as decorative Christmas lights or connecting multiple extension cords, it is always necessary to arrange the cords in a manner that ensures a male plug is adjacent a female receptacle. In some configurations, gendered connectors require specialized adapters, such as to join two functionally equivalent cables together. For example, telephone extension cords are well-known as having gendered plugs, but having the same gender on both ends of a cable. Consequently, an additional adapter having the complementary gender on both ends is required to connect such cables to gain greater length. Another type of gendered coupling is used to provide mechanical connection of toy trains using magnetic attraction. Although the connectors on the end of each train appear visually to be genderless, in fact, each will only engage if a positive magnetic pole is placed adjacent a negative magnetic pole. Consequently, such connectors are functionally gendered. 
   Genderless, or hermaphroditic, couplings typically have one connector type designed to engage with an equivalent connector in a complementary fashion. Since each connector is identical, there is no need for specialized adapters when connecting identical genders together. An example of a well-known hermaphroditic connector is the “handshake” devices on rail cars that enable any rail car to mechanically link to any other car in any order. Current hermaphroditic connectors are complex and expensive to produce. Further, actual engagement of opposing hermaphroditic connectors can likewise be difficult. Still further, many such connectors engage in a linear fashion causing electrical connections to be made simultaneously on all contacts creating potential short-circuits and safety hazards. Additionally, many such hermaphroditic connectors require relatively long shells to house the components used to mechanically engage respective connectors. Without special complex adaptation, many gendered and genderless connectors are easily separated, creating inconvenient disconnects. Further, existing hermaphroditic connectors cannot be easily or cost-effectively scaled or modified to accommodate varying power and signal pathways. 
   Information relevant to attempts to address these problems can be found in U.S. Pat. Nos. 6,605,914B1 and 6,881,084B2. However, each one of these references suffers from one or more of the following disadvantages: long housings, complex configuration, expensive construction, poor contact tolerance, potentially unsafe contact action, and, lack of resistance to linear separation. 
   For the foregoing reasons, there is a need for a novel hermaphroditic coupling that is low cost, comprised of few components, easily assembled, safe in operation, capable of providing close tolerance engagement, structurally robust, resistant to rotational, lateral or linear disengagement, scalable to accommodate increasing numbers of connection pathways, and, easily modifiable to deliver various connection contact configurations. 
   SUMMARY 
   The present invention is directed to a novel hermaphroditic coupling comprised of two shallow, low profile connector members that satisfy this need for low-cost, simplicity, ruggedness, adaptability, scalability, low-profile, safety, close connection tolerance, and, resistance to separation. The coupling comprises two identical low-profile connectors: a first genderless connector which rotationally engages and joins with a second, equivalent genderless connector. The completed coupling forms mechanical, electrical and optical linkage to power cables, signal cables, strength members or other objects attached to the backplane or attachment face of each connector. Each connector has a generally low-profile, flat shape and in one version the overall shape is that of a truncated circle or disc. A rear face on each connector provides a surface for connection or attachment of objects, including cables, toy components and other objects. Each connector includes a gap for rotationally receiving and engaging an interlocking extension and tab of an opposing connector. Each connector further includes flexible spring levers with locking protrusions, where the levers are bent inward during initial rotational engagement and then the protrusions seat in a corresponding notch on the opposing connector when fully engaged. Each connector has holes or penetrations for receiving surface interface devices such as electrical or signal transmission contacts. In one version, the holes are placed in a linear fashion such that individual holes, and hence, the contacts, may be aligned in a preferred sequence based upon the rotational action of engagement. Thus, the desirable, shallow profile coupling is easily formed by an intuitive and simple operation to provide secure engagement between interface or contact surfaces, while also providing resistance to linear and rotational separation. 

   
     DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings where: 
       FIG. 1  provides a perspective view of a completed coupling comprising two genderless connectors according to a preferred embodiment of the invention; 
       FIG. 2  provides a perspective view of a connector of the coupling of  FIG. 1 , according to a preferred embodiment of the invention; 
       FIG. 3  provides a front view of the connector of  FIG. 2 , according to a preferred embodiment of the invention; 
       FIG. 4  provides a top view of the connector of  FIG. 2 , according to a preferred embodiment of the invention; 
       FIGS. 5A-5C  provide a perspective view and illustration of the coupling process between two connectors, according to a preferred embodiment of the invention; 
       FIG. 6  provides a front view of a fully engaged coupling as shown in  FIG. 1 , according to a preferred embodiment of the invention; 
       FIG. 7  provides an enlarged view of a spring lever protrusion of a first connector engaging a notch of a second connector when fully engaged as shown in  FIG. 6 , according to a preferred embodiment of the invention; and, 
       FIG. 8  is a cross-sectional view of the connector of  FIG. 6  taken along the line  8 - 8  according to a preferred embodiment of the invention. 
   

   DESCRIPTION 
   The invention provides a reliable mechanical connection resistant to tensile, lateral and rotational separation forces while simultaneously providing secure electrical or optical connection with multiple contacts for power, signal, and ground. 
   A shown in  FIG. 1 , in a first embodiment according to the present invention, coupling  10  comprises a first genderless connector  31  and a second genderless connector  32 . For consistency, given that connectors  31 ,  32  are hermaphroditic and hence identical in all aspects to another opposing connector, equivalent elements on either connector  31 ,  32  have been given equivalent reference numerals. Each equivalent element will occasionally be related to either the first connector  31  or the second connector  32  when describing the use and operation of the connectors  31 ,  32 . 
   Now, and in further detail, as shown in  FIG. 2 , a connector  31  includes a mating or joining face  20  and a rear attachment face  22 . An engaging spring lever  11  having a protrusion  12  extends from the joining face  20 . Corresponding overhanging and interlocking tabs  16  of each connector  31 ,  32  are configured to rotateably engage and interlock with corresponding gaps  17  of an opposing connector  31 ,  32 . A notch  19  of the overhanging tab  16  is sized to receive the protrusion  12  of the spring lever  11 . Each joining face  20  includes connector holes or penetrations  80  for receiving various forms of interface contacts. 
   Now, with reference to  FIGS. 1-4 , the coupling  10  and connectors  31 ,  32  of a first embodiment of the present invention are described in even greater detail. Each connector  31 ,  32  comprises a joining face  20 , an opposing attachment face  22 , a top edge  14 , and, a bottom edge  15 . With specific reference to  FIG. 3 , each connector  31 ,  32  in a first embodiment is shaped in the form of a truncated circle or disc with a flattened top  14  and bottom  15 . The parallel top  14  and bottom  15  form flat surfaces which truncate the overall circular shape of each connector  31 ,  32  to form a disc area  24 . The joining face  20  of a first connector  31  engages with an opposing joining face  20  of another equivalent but separate second connector  32 . The rear attachment face  22  of each connector  31 ,  32  is affixed to an object (not shown). The objects may include wires, cables, optical fibers, rigid or flexible strength members, facial portions of toys such as trains, or any other such object which requires attachment to another object. 
   Now, with particular attention to  FIGS. 2 and 3 , each connector  31 ,  32  includes a flat joining face  20  in the shape of a truncated circle forming a disc area  24  with flattened top  14  and bottom  15 . Spring levers  11  including outwardly pointing engaging protrusions  12  located at opposing corners of each connector  31 ,  32 . Each spring lever  11  extends from the disc area  24  shaped with curvature generally following a circular path about the lower left and upper right corners of the joining face  20 . Although the levers  11  are shown here as extending in a clock-wise direction, one skilled in the art will readily recognize that the levers  11  and connectors  31 ,  32  can be configured in a different additional embodiment such that the spring levers  11  would extend in a counter-clockwise direction about the curved perimeter of the disc area  24 . A first fixed end  94  of each spring lever  11  extending from the disc area  24  originates adjacent the top  14  and bottom  15  surfaces of the each connector  31 ,  32 . A free end  96  of each lever  11  includes a protrusion  12  directed outwardly. A recess  92  is formed in the disc area  24  of each connector to receive the free end  96  of the spring lever  11 . When connection is completed, and the first connector  31  and the second connector  32  have been rotateably engaged to form the coupling  10 , the protrusions  12  on the levers  11  of the first connector  31  are accommodated and frictionally engaged in the notches  19  within the inner edges  90  of the overhanging interlocking tabs  16  of the second connector  32 . 
   Now, with reference to  FIG. 2 , each connector  31 ,  32  includes two opposing extensions  13 . The extensions  13  extend outwardly from the rear attachment face  24  of each connector  31 ,  32 . The extensions  13  border the levers  11 . In a first embodiment of the present invention, the extensions  13  extend horizontally from and form a portion of the top  14  and bottom  15  of each connector  31 ,  32  thereby continuing the planes of truncation. As shown in  FIGS. 2 and 3 , outer edges  98  of the extensions  13  form arcs concentric with the overall circular shape of each connector  31 ,  32 . The extensions  13  include fastening holes  102  to allow physical attachment of a connector  31 ,  32  to another object by insertion of fasteners such as screws (not shown). The holes  102  may also be used to more permanently engage the first connector  31  to a second connector  32  to form the coupling  10 . 
   With further reference to  FIGS. 2 and 3 , the connectors  31 ,  32  include two opposing overhanging, interlocking tabs  16 . The tabs  16  of the first connector  31  protrude outward from the joining face  20  towards the joining face  20  of the second connector  32 . The tabs  16  are situated opposite the extensions  13  but likewise extend horizontally in the plane of truncation but in a curvature concentric with the overall circular shape of the connector  31 ,  32 . A distal end  104  of each tab  16  arcs towards a midline of the connector  31 ,  32  parallel to and equidistant from the two planes of truncation of the top  14  and bottom  15  of the connector  31 ,  32 . The distal ends  104  of the overhanging tabs  16  form an engaging portion  106 . The tabs  16  are shown having a tapering shape which serves to allow the connectors  31 ,  32  to be easily and accurately connected. 
   As shown in both  FIGS. 2 and 4 , the extension  13  and the corresponding but opposing overhanging and interlocking tab  16  of a connector  31 ,  32  forms a gap  17 . The gap  17  of a first connector  31  is sized and shaped to fully receive and frictionally engage and interlock with the engaging portion  106  of a corresponding tab  16  of a second connector  32 . 
   As shown in  FIGS. 2 and 3 , the tabs  16  include recessed notches  19  on inner edges  90 . The notches  19  are sized to receive and frictionally engage the protrusions  12  of the spring levers  11  when a first connector  31  is fully engaged with a second connector  32 . The force of frictional engagement may be varied by modifying the thickness of the spring lever  11  or changing the shapes of the protrusions  12  and the recessed notches  19 . In a further embodiment, the notches  19  may have a shape of a rectangular slot to correspond to a rectangular protrusion  12  such that a fully engaged coupling  10  is permanently engaged and may not be released by reverse rotation. 
   In a first embodiment, each connector  31 ,  32  includes penetrations  80  through the joining face  20  of the connector  31 ,  32  to the attachment face  22 . As shown in  FIG. 2 , the face  20  of the connector  31 ,  32  includes two sets  18  of four rectangular penetrations  80  to create a total of eight penetrations  80 . In a first embodiment, each set  18  of four penetrations  80  is aligned in a horizontal row located along a midline of the connector  31 ,  32 , where one of each set  18  is located on each side of the connector&#39;s  31 ,  32  center. The penetrations  80  are sized to receive various forms of contacts  87  to facilitate power and signal transmission. In a first embodiment of the invention, electrical contacts  87  are placed in each penetration  80 , slightly protruding outward from the joining face  20  of the connector  31 ,  32 . 
   Mechanical Connection—In use and operation,  FIGS. 5A-5C  illustrate three steps of engaging a first connector  31  with a second connector  32  to form the novel hermaphroditic coupling  10  of a preferred embodiment of the invention.  FIG. 5A  shows a first step of connection and engagement between the two connectors  31 ,  32 . First, the two connectors  31 ,  32  are oriented for engagement with joining faces  20  oriented toward each other and each connector  31 ,  32  slightly rotationally offset from the other. Next, as shown in  FIG. 5B , the connectors  31 ,  32  are brought together with joining faces  20  abutting and the connectors  31 ,  32  rotationally offset from one another by approximately forty-five degrees such that each hermaphroditic connector  31 ,  32  simultaneously receives the top  14  and bottom  15  of the opposing is connector  31 ,  32 . Once each connector  31 ,  32  is engaged by its opposing and identical connector  31 ,  32 , the connectors  31 ,  32  are rotated in opposing directions. Since each connector  31 ,  32  is rotationally symmetric, the connection may be initiated without regard to a “right-side-up” orientation. On first contact, the overhanging and interlocking tabs  16  extend over the top  14  and bottom  15  surfaces of the opposing connector  31 ,  32 , continuing in an arc over the first fixed end  94  of the adjacent spring lever  11 . 
   The two connectors  31 ,  32  are rotated in a direction opposite each other such that distal ends  104  of the tabs  16  travel towards receiving gaps  17 . As the connectors  31 ,  32  approach alignment with one another, the inner edge  90  of each tab  16  contacts the protrusion  12  on the spring lever  11 , compressing the lever  11  towards the center of the connector  31 ,  32  and into its recess  92 . Each interlocking tab  16  then continues to slide into the gap  17  between the opposing tab  16  and the extension  13 . The connectors  31 ,  32  are continually rotated until fully engaged to form the coupling  10 . 
   Now, as shown in  FIG. 5C , a fully engaged coupling  10  has the top  14  and bottom  15  of the coupled connectors  31 ,  32  fully aligned. During rotational engagement, as the tabs  16  interlock and completely overlap and are eventually fully received within the gaps  17 , the protrusion  12  of each spring lever  11  slides and springs into the corresponding notch  19  along the inner surface  90  of each tab  16 . This final rotational engagement creates a locking action and a feeling of positive engagement as evidenced by the sense of engagement of the protrusions  12  in the notches  19 . Additionally, as the protrusions  12  fully and frictionally seat in the notches  19 , the engagement of the tabs  16  within the gap  17  and with each other fully prohibits linear axial, rotational and lateral separation of the connectors  31 ,  32 . 
   To disengage the connectors  31 ,  32 , the connectors  31 ,  32  are rotated in an opposite direction so as to restore the initial rotational offset, and, to rotate the tabs  16  out of the gaps  17  and to remove the overlap between the tabs  16 . The connectors  31 ,  32  may then be separated from each other. 
   An alternative embodiment of the invention includes a mirror-image arrangement where the locking action requires rotation in the opposite direction as that described above. 
   Electrical Connection—As noted above, the connectors  31 ,  32  may also be used to form a coupling  10  to provide electrical connectivity between coupled objects. Now, and referring to  FIG. 6 , in a preferred embodiment, the connector  31 ,  32  is designed to receive one or more electrical contacts  87  in one or more penetrations  80 . Each set  18  of contacts  18  is a mirror image of the other. As shown in  FIG. 6 , in a first embodiment eight penetrations  80  support eight contacts  87 . The contacts  87  are arranged as follows: an innermost contact  81  (closest to the center of the disc) provides connectivity to a grounding circuitry; the next two contacts  82 ,  83  further from the center of the connector joining face  20  are signal paths; and finally, the outermost contact  84  is used to provide power. Each contact  87  in one set  18  of four contacts  87  is electrically connected to its equivalent contact  87  in the symmetric set  18  of four contacts  87  using a conducting material ribbon  88  set in channels  85  of the attachment face  24  of each connector  31 ,  32 . As shown in  FIG. 8 , when used for providing transmission of electrical power or signals, the connector  10  includes at least one electrical contact  87  between a first and second connector  31 ,  32  according to a preferred embodiment of the invention. 
   In operation and using the above described arrangement, when two connectors  31 ,  32  are engaged and rotated to secure a connection, the innermost matching set of contacts, the ground contacts  81 , make the first initial electrical contact. Next, as rotation continues, the next matching set of contacts to engage are the signal connectors  82 ,  83 , and lastly, the power contacts  84 . This order of connection helps to avoid short circuits.  FIG. 8  illustrates a section along the plane  8 - 8  cut through the coupling  10  to show the electrical connection between two protruding contacts  87 . Other arrangements of contacts  87  are possible, such as more or fewer contacts in different locations. 
   The previously described versions of the present invention have many advantages, including simple engagement, flexible use, low profile, safe connectivity, scaleable to multiple contacts, resistant to lateral, linear and rotational separation, and low cost among other things. The invention does not require that all the advantageous features and all the advantages need to be incorporated into every embodiment of the invention. 
   Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, the connectors can be imbedded in a wall outlet to provide secure and inseparable connectivity with networking or power cables. In addition, the connectors can be attached to cables of differing lengths to allow creation of any cable length having equivalent functionality. Further, the connectors can be used strictly to provide secure mechanical connection for structural components including toys or other structures. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions or embodiments contained herein. 
   The reader&#39;s attention is directed to all papers and documents which are filed concurrently with this specification and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All the features disclosed in this specification including any accompanying claims, abstract, and drawings may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 
   Further, any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112, ¶6. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. §112, ¶6. 
   Moreover, no requirement exists for a device or method to address each and every problem sought to be resolved by the present invention, for such to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.” 
   INDUSTRIAL APPLICABILITY 
   The present invention applies industrially to connectors to form a coupling between objects. More particularly, the present invention applies industrially to connectors for forming secure connections between object. Even more particularly, the present invention applies to hermaphroditic connectors for use in connecting power, ground and signal systems.