Abstract:
A connector for attachment to an extending transformer stud. The connector includes an elongate central body having a central aperture and an opening at one end for insertable accommodation of the transformer stud. The central aperture accepts a single or more than one size stud without increasing the size and cost needed for two separate mounting holes. The connector according to the present invention accepts the pitch of at least two different size threads and with the typical setscrew locking arrangement, maintains thread engagement on one side of the stud, thus securing the stud. The connector according to the present invention further provides a connector threadform having a reduced threadform angle than the stud threadform to provide greater conductivity and reduced electrical resistance between the stud and connector at lower set screw torque settings.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority to U.S. Provisional Application No. 60/583,869, filed Jun. 29, 2004, which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to a connector for connecting to a transformer having and more particularly, to a transformer stud connector, having a unique thread profile, which permits the connector to be installed on the transformer stud with lower torque on set screws.  
       BACKGROUND OF THE INVENTION  
       [0003]     Electrical transformers are typically used to distribute electrical power from main utility lines for secondary distribution. The transformer accepts the main utility line on the primary side of the transformer and distributes the power from a secondary side of the transformer. An electrical step-down is provided by the transformer so as to provide for the proper secondary distribution of electrical power for residential and commercial use.  
         [0004]     The transformer is normally housed in a steel cabinet. A threaded copper stud extends from the secondary side of the transformer from which secondary distribution is provided. Plural electrical conductors, connected to the threaded stud, provide for distribution of power to the end user.  
         [0005]     In order to connect the conductor to the stud, a transformer stud connector is employed. These transformer stud connectors are elongate, electrically conductive members which are inserted over the copper stud extending from the secondary side of the transformer. The stud connector may be threadingly attached to the transformer stud. Extending longitudinally therefrom are a plurality of conductor accommodating ports wherein the ends of conductors may be inserted. Each conductor port has an associated set screw to effect mechanical and electrical connection to the transformer stud connector. Examples of transformer stud connectors are shown in U.S. Pat. Nos. 5,931,708; 5,848,913; 5,690,516; DES 377,782; DES 346,150; and DES 309,664.  
         [0006]     In a typical arrangement, the utility distribution transformer has threaded studs typically ⅝-11 or 1-14. A connector, sometimes referred to as a bus bar, is used to connect to the stud and provide ports for multiple wire connections. The connector is threaded with the same pitch thread but the threaded hole is equal or larger to the diameter of the transformer stud. The larger threaded hole allows the connector to be slipped on to the stud, known as a slip fit connector, instead of being spun onto the treaded shaft. This allows the connector to be installed and removed without having to remove any of the conductors. An orthogonally mounted setscrew is typically used to secure the connector to the studded shaft.  
         [0007]     In prior art connectors, various means were provided so that a single connector could be used to service studs of various sizes. One way is to provide at least two threaded holes, one for each of the stud sizes serviced by the connector. However, the disadvantage of such design is that it requires at least two holes, and therefore needs to be larger than necessary. Also, because by design the stud hole has to meet a certain depth to accommodate the stud, the portion of the connector receiving the threaded stud in not usable for conductor connections, thus additionally requiring a longer connector to accommodate an equal number of conductors. This problem is exacerbated for connectors having multiple threaded holes.  
         [0008]     A further prior art design utilizes a tear-drop design of two holes which both intersect and overlap and therefore produce a large diameter hole which may or may not be threaded. It has an arc-section of a smaller hole at the bottom of the larger hole, which extends beyond the perimeter of the larger hole. This design is commonly known as the “tear-drop” design. The disadvantage of this design is that it requires pre-drilling a smaller hole, followed by drilling of the second larger hole, partially overlapping the smaller hole. Alternately, the larger hole can be bored first, followed by milling or broaching of the bottom arc section to create the “tear-drop”. Both methods therefore require a two-step process, which adds complexity and expense to the manufacturing process.  
         [0009]     A third alternative prior art design utilizes a slider system mounted to the connector which has grooved sides at various levels on the connector body. By moving the slider in the grooves, various gap sizes between the slider and the connector body can be formed. However, this design requires a second element, the slider, to be added to the connector, which adds complexity and expense to the manufacturing process.  
         [0010]     It is therefore desirable to provide a transformer stud connector, which can be mounted on studs of various sizes without the complexity, or cost of prior art designs and which has a more compact design and which provides for improved conductivity between the stud and connector without excessive torque being used to secure the connector.  
       SUMMARY OF THE INVENTION  
       [0011]     The present invention provides a connector, which can be attached to transformer studs of various sizes with a single threaded hole.  
         [0012]     The present invention therefore provides a connector for attachment to an extending transformer stud. The connector includes an elongate central body having a central aperture and an opening at one end for insertable accommodation of the transformer stud. The central aperture can be designed to accept more than one size stud without increasing the size and cost needed for two separate mounting holes. The connector according to the present invention can also be designed to accept the pitch of one or more than one different size thread. It may also incorporate the typical setscrew locking arrangement that maintains thread engagement on one side of the stud, thus securing the stud. The connector according to the present invention further provides a threadform having a reduced threadform angle to provide greater conductivity and reduced electrical resistance between the stud and connector at a lower set screw torque setting than a standard thread.  
         [0013]     It is well known in the art to create threads for fastening and other applications typically by tapping or machining the proper size thread (male or female) according to the various thread standards/classes applicable. The threads are typically uniform in shape/profile throughout the threaded length of the part bearing threads. The threads are made to work with same size and type threads of a complementary part.  
         [0014]     The present invention uses a single hole, passageway or bore within the body of a connector to accept one or more threaded studs of a transformer. Furthermore, in one embodiment the connector utilizes a distinct special threadform having an angular slope that is different and preferably reduced with respect to the standard connector stud threads. This different angular slope thread produces a two-point contact on each thread along its arc, thereby ensuring greater conductivity and reduced electrical resistance in the region of interconnection. In an alternate embodiment, the connector of the present invention utilizes an internal thread wherein the pitch dimension of each thread is larger than the thread valleys of the same internal thread.  
         [0015]     The present invention therefore provides an electrically conductive transformer stud connector comprising a body with a longitudinal cylindrical bore or the like, wherein the connector thread has a threadform angle that is less than a threadform angle of the stud thread, the longitudinal cylindrical bore is in communication with at least one set screw port and having a set screw threadably received therein for exerting a clamping force upon the transformer stud, and at least one conductor port for receiving a conductor, each conductor port being in communication with a set screw port and having a set screw threadadly received therein for exerting a clamping force upon the conductor.  
         [0016]     As shown by way of a preferred embodiment herein, the connector of the present invention includes an overlapped thread configuration placed along the threadform. Each thread accommodates a stud of different thread pitch and are overlapped tangently. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0017]      FIG. 1  shows an end view of a transformer stud connector showing two threads tapped into the end and with section lines  3 - 3  indicated thereon.  
         [0018]      FIG. 2  shows an perspective view of a transformer stud connector according to the present invention.  
         [0019]      FIG. 3  is a cross-sectional drawing of a connector according to the present invention at section  3 - 3  of  FIG. 1 .  
         [0020]      FIG. 4  is detail area of the cross-sectional drawing of  FIG. 3 .  
         [0021]      FIG. 5  is a perspective view of the transformer stud connector having a stud inserted therewith.  
         [0022]      FIG. 6  is a top view of the transformer stud connector according to the present invention with section lines  7 - 7 .  
         [0023]      FIG. 7  is a cross-sectional drawing of a connector and transformer stud according to the present invention at section  7 - 7  of  FIG. 6 .  
         [0024]      FIG. 8  is an detail area of the cross-sectional drawing of  FIG. 7 .  
         [0025]      FIG. 9  is an alternate cross-sectional drawing of a connector and transformer stud according to the present invention at section  7 - 7  of  FIG. 6 .  
         [0026]      FIG. 10  is a detail area of the cross-sectional drawing of  FIG. 9 .  
         [0027]      FIG. 11  is a cross-sectional drawing of an internal thread of an alternate embodiment according to the present invention.  
         [0028]      FIG. 12  is a cross sectional drawing of an external thread of an alternate embodiment according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]     Referring to  FIG. 1 , there is shown an end view of the transformer stud connector  100  according to the present invention having a central aperture  102  tapped into the end for receiving a transformer stud. The end view of this embodiment shows the connector  100  having a central body,  104  a upper body  106  and an lower body  108 . The upper and lower bodies have conductor ports, (not seen is this view) projecting laterally from the sides and threaded set screw apertures  110  aligned along the top of each body for receiving a set screw for affixing the conductors to the connector  100 . As will be further described hereinafter, the central aperture  102  shown in this embodiment is tapped with threads  112  for receiving a transformer stud. The connector  100  is an integrally formed metallic member, preferably formed of aluminum or other material, having high electrical conductivity. Transformer stud central aperture  102  is a generally elongate cylindrical bore or passageway which is at least partially internally threaded  112  to accommodate the extending, externally threaded transformer stud (not shown). The length of bore need only be approximately the length of the extending portion of the stud so that when the connector  100  is placed over the stud, the stud and the bore extend generally the same distance. Preferably, the central aperture  102  is comprised of a small diameter threaded region and a large diameter threaded region although it is conceivable to have more or less than two such threaded regions. The radius of curvature of the small diameter threaded region and the large diameter threaded region are offset within the central aperture  102  by a linear distance, which is variable depending on the radius of each region.  
         [0030]     In a preferred embodiment of the present invention, the connector  100  is produced by forming the central aperture  102  by drilling into the connector  100  to create a void. Thereafter, a first tap operation is performed to form the small diameter threaded region, which in the preferred embodiment may be a ⅝-11 thread. Once the small diameter threaded region is formed, a second tap operation is performed to form the large diameter threaded region, which in the preferred embodiment may be 1⅛-14 thread. The threaded regions are positioned within the connector  100  by offsetting the radius of curvature of the threads to be machined creating a tangency point or line of tangency of the two threaded regions directly opposite the setscrew, and also providing a single line of tangency, in a three dimensional frame of reference, along the two thread pitches. Removal of the overlapping thread sections could be done by a milling/threading/tapping operation on the side of central aperture  102  where interlocking of the transformer stud is desired, typically opposite the setscrew. Alternately, the overlapping thread sections can be formed at other locations around the entire inner diameter of central aperture  102 .  
         [0031]     In the preferred embodiment, specially cut taps can be utilized to produce a variety of thread types supplying the proper thread profile for contact surface maximization.  
         [0032]     While the preferred embodiment of the connector  100  according to the present invention is described with respect to a particular large and small thread pitch. It would be clear to one skilled in the art that any standard or non-standard thread pitches could be overlapped in the manner described. Likewise, the present invention need not be limited to overlapping two particular thread pitches, but may include a single thread pitch or more than two particular thread pitches that are formed within central aperture  102 .  
         [0033]     Turning now to  FIG. 2 , there is shown a perspective view of a connector  100  according to the present invention showing conductor ports  202  for receiving conductors on lower body  108 , with threaded set screw apertures  204  aligned along the top of upper body  106  and lower body  108 . Furthermore, the rear of conductor ports  202  are partially visible along the rear face of upper body  106 . Central body  104  has aligned along its top face threaded set screw apertures  206  for receiving set screws for securing the transformer stud (not shown) within the connector  100 . Each conductor port  202  will also include a securement device such as a setscrew for securing the conductor. Each setscrew aperture  204  is in communication with the respective conductor port  202  so that setscrews (not shown) may be inserted therein to mechanically and electrically secure the ends of the conductors within the stud connector  100 . In a typical arrangement, each of the set screw apertures  204  extend from one side surface of the connector  100 . The conductor ports  202  are generally positioned on similarly facing surfaces of their respective body  106 ,  108  so that conductors inserted into each of the ports  202  can be inserted from the same direction.  
         [0034]     Turning now to  FIG. 3 , there is shown a cross sectional view of the connector  100  of  FIG. 1 , along section line  3 - 3  which coincides with the line of tangency between the two threaded regions tapped into connector  100 . Depicted is the sectional view of the connector  100  according to the present invention. Depicted is a cross section of the central body  104  showing the central aperture  102 . The central aperture,  102  is tapped with different size threads. In the connector depicted, the central aperture  102  is tapped to receive a 1⅛″ connector stud and a ⅝″ connector stud. The center of the 1⅛″ tapped hole  302  and the ⅝″ tapped hole  304  are offset within the single central aperture  102 , such that the threads  112  of each tapped hole lie tangent to each other along the inner diameter of aperture  102 . Further shown in  FIG. 3  are cross sectional views of set screw apertures  206 , which would typically be threaded.  
         [0035]     Turning now to  FIG. 4 , there is shown a detail view of the cross sectional view of threads  112  shown in  FIG. 3 . The detail view shows threads  112  arranged along the line of tangency between the two threaded regions of the central aperture  102 . The figure depicts threads tapped to receive 1⅛″ connector stud threads  402  and ⅝″ connector stud threads  404 . The figure shows the root  406  and crest  408  of each thread which define the thread height. Connecting the root  406  to the crest  408  are the flanks  410  which establish the threadform angle of the internal threads  112 . The flanks  410  diverge from the root  406  at an angle to form the walls of the threadform. The angle that the flanks diverge from the root to the crest is determined by the size of the stud to be used with the connector within a particular tolerance class. In other words, for a particular size stud thread  402 ,  404  a corresponding size threadform is utilized to match the stud threads  402 ,  404 . The stud thread and connector threadform correspond in size within a particular tolerance class. For the connector  100  according to the present invention the threadform has two thread sizes overlayed tangently within the connector central aperture. In the connector according to the present invention, the ⅝″ threadform have a threadform angle  405  by which the flanks diverge which is smaller than a standard threadform angle for a similarly sized stud thread. Specifically, while the threadform angle  405  for a standard threadform of a ⅝″ thread would typically be 60°+/−½°, according to the present invention, the threadform described herein for connector  100  contains threads with a smaller threadform angle  405  not exceeding 59½°. Likewise, the threads corresponding to the 1″-stud typically have an threadform angle  405  of 60°+/−½°, while the threads of the connector  100  of the present invention have an threadform angle  405  of less than 59½°.  
         [0036]     Turning now to  FIG. 5 , there is shown a perspective view of the connector  100  according to the present invention, wherein the connector is threaded onto a stud  500 . The stud  500  has a threaded portion, not visible in this view, a collar  502  which abuts the connector  100  and a flange  504 , having apertures  506  for receiving fasteners, such as bolts for attaching the stud to a transformer. There is also shown a spade lug  508  for providing an electrical connection between the transformer and stud  500 . In the view depicted stud set screws  510  are shown threaded into the top of the connector central body  104 . The stud set screws  510  is received into the connector body in a threaded bore  206  and can thus be raised or lowered by rotating the setscrew. In this way, the setscrew can be adjusted to contact a threaded stud  500  within central aperture  102 . The stud set screws  510  exert a clamping force on the stud  500  in order to mechanically secure it in place within connector  100  as well as ensure optimum conductivity. Typically the set screws  510  are torqued to a value of approximately  240  inch pounds to achieve sufficient clamping. The exterior of the stud  500  depicted in  FIG. 5  is representative of the different size studs, 1″, and ⅝″, described herein. Regarding the portion not visible, the stud  500  will differ in size from each other and will be further described hereinafter.  
         [0037]     Turning now to  FIG. 6  there is shown a top view depicted of the connector  100  of the present invention assembled to a transformer stud  500 . The view depicts the top of the connector central body  104  and upper body  106  and lower body  108 . Also visible are stud set screws  510  as well as threaded set screw apertures  110  aligned along the top of each body  106 ,  108  for receiving a set screw for affixing the conductors to the connector  100 .  
         [0038]     Turning now to  FIG. 7  there is shown a cross sectional view of the stud connector  100  according to the present invention along cross section  7 - 7  shown in  FIG. 6 . In this view there is shown a transformer stud  500  installed within central aperture  102 , the stud  500  having a diameter slightly smaller than central aperture  102 , such that the connector  100  can be slipped over stud  500  without the stud  500  and connector  100  threads becoming engaged. Once the stud  500  is fully inserted within the connector  100 , setscrews  510  are rotated to bear against stud  500 , thereby causing the threaded portion  700  of stud  500  to engage the complementary pitch threads along their arc within central aperture  102  and thus secure the connector  100  to the stud  500 . More specifically,  FIG. 7  shows the threaded portion  700  of stud  500 , assembled with connector  100 . In this exemplary depiction, there is shown a 1″ diameter stud  500  assembled with connector  100 . Stud set screws  510  are shown in a tightened position, in which the set screws  510  bear against the top  702  of the threaded portion  700  of stud  500 . The bottom  704  of the threaded portion  700  bears against a threaded region or arc of the threads  112  of connector  100  due to the normal force exerted upon the threaded portion  700  of stud  500 . As will be further shown and described with respect to  FIG. 8 , the threaded portion  700  contacts the threads  112  of connector  100  in such a was so as to provide two point contact between the threads along an arc for greater conductivity and reduced electrical resistance.  
         [0039]     Turning now to  FIG. 8  there is shown an expanded view shown in  FIG. 7 .  FIG. 8  shows the bottom  704  of the threaded portion  700  of stud  500  in cooperative engagement with threads  112  of connector  100 . The bottom  704  of the threaded portion  700  of the stud have a standard threadform angle  405 . In the exemplary depicted a 1″ diameter stud is shown having a threadform angle  405  of 60.0°+/−½°. The threads  112  of connector  100  have a smaller threadform angle along their arc than the standard threadform for the 1″ stud depicted, in this exemplary depiction approximately 59½° or less. By narrowing the threadform angle of connector  100  in accordance with the present invention, the threads  112  of connector  100  contact the stud on two locations  800  at each stud thread crest  802  along an arc. In that way greater conductivity and reduced electrical resistance can be achieved at lower set screw torque settings than a standard thread connector.  
         [0040]     Turning now to  FIG. 9  there is shown a cross sectional view of the stud connector  100  according to the present invention along cross section  7 - 7  shown in  FIG. 6 .  FIG. 9  shows the threaded portion  700  of stud  500  assembled with connector  100 . In this exemplary depiction, there is shown a ⅝″ diameter stud  500  assembled with connector  100 . Stud set screws  510  are shown in a tightened position, in which the set screws  510  bear against the top  702  of the threaded portion  700  of stud  500 . The bottom  704  of the threaded portion  700  bears against the threads  112  of connector  100  along an arc due to the normal force exerted upon the threaded portion  700  of stud  500 . As will be further shown and described with respect to  FIG. 10 , the threads of threaded portion  700  contact threads  112  of connector  100  in such a was so as to provide two point contact between the threads along an arc for greater conductivity and reduced electrical resistance.  
         [0041]     Turning now to  FIG. 10  there is shown an expanded view shown in  FIG. 9 .  FIG. 10  shows the bottom  704  of the threaded portion  700  of stud  500  in cooperative engagement with threads  112  of connector  100 . The bottom  704  of the threaded portion  700  of the stud have a standard threadform angle  405 . In the exemplary depiction a ⅝″ diameter stud is shown, having a threadform angle of 60.0°+/−½°. The threads  112  of connector  100  have a smaller threadform angle  405  along their arc than the standard threadform for the ⅝″ stud depicted, in this exemplary depiction approximately 59½°. By narrowing the threadform angle in accordance with the present invention, the threads  112  of connector  100  contact the stud on two locations  800  at each stud thread crest  802  along an arc. In that way, greater conductivity and reduced electrical resistance can be achieved at lower set screw torque setting than a standard thread connector.  
         [0042]     Turning to  FIG. 11  there is shown an alternate embodiment of the present invention. In the alternate embodiment depicted, the connector of the present invention utilizes an internal thread wherein the pitch dimension of each thread is larger than the thread valleys of the same internal thread. Turning now to  FIG. 11  there is shown an enlarged view of connector  100  depicting thread  112 . Thread  112  is comprised of two opposing flanks  1102  and  1104 , which converge to a peak  1106 . The peak  1106  being the uppermost point of the thread. In the exemplary thread  112  depicted, the peak  1106  of each thread does not converge at a single point, but instead the peak is truncated from the point of convergence. The amount that the peak is truncated is defined in relation to the height of the thread. The height (H)  1108  defined as the distance from the virtual point of convergence between flanks at the root  1108  to the virtual point of convergence at the peak  1106 . The peak in  FIG. 11  is truncated by a distance equal to H/4.  1107  The shortening of the peak produces surface  1114  that is parallel to the axis of the thread, wherein the longitudinal length is given as p/4  1115 . Furthermore, the virtual point of convergence at the root  1108  is also truncated by filling a portion of the valley  1118  at the convergence of the flanks. The valley is filled to a depth of H/8  1119 . The dimensions of the surface of the filled area is determined in accordance with standard dimensions for similarly sized threads, wherein the length of the area  1120  is given as p/8. The connector  100  threads  112  therefore have a height from the truncated valley to the truncated peak, that is given by ⅝ H  1121 .  
         [0043]     Unlike the previously described embodiment, the embodiment of connector  100  depicted in  FIG. 11 , has a threadform angle  405 , that is determined in accordance with the usual or customary threadform angle for threads of a particular size. In the example depicted, the treadform angle  405  is 60°+/−½°. However, the thread  112  pitch dimension is larger for each thread than for the thread valley that separates each thread. Referring again to  FIG. 11 , there is shown the pitch line  1122 . The pitch line  1122  is the distance between any two adjacent corresponding locations on the threadform. This distance can be measured in one of three ways: peak to next peak, valley to next valley, or from a point on a particular thread to the same point on the thread. In the exemplary thread depicted, the pitch distance is denoted by the pitch line  1122 , which marks the distance from a point on a particular thread  1123 , to the corresponding point in the next thread  1125 , thereby measuring the length of one cycle of thread and valley. Furthermore, segments of the pitch line  1122 , are delineated as “a”  1124 , and “b”  1126  respectively, denoting the portion of the total distance of the pitch line for the valley “a”  1124  and the thread “b”  1126 . The total pitch line  1122  (p) distance is given as (p=a+b), where a &lt;p/2, b&gt;p/2; a≠b and a&lt;b. In this way, the thread pitch is varied such that the distance between each thread is shorter than that of a typical thread of the same nominal size.  
         [0044]     As will be further shown and described with respect to  FIG. 12 , due to the variation in thread pitch, when a stud of the same nominal size and having a typical thread profile is threaded into connector  100  contacts the threads  112  of connector  100  in such a was so as to provide two point contact between the threads along an arc for greater conductivity and reduced electrical resistance. The two point contact between the stud and connector is achieved because the distance between the threads of connector  100  is shorter that the distance between threads of stud  500 . By shortening the thread pitch length of connector  100  in accordance with this embodiment of the present invention, the threads  112  of connector  100  contact the stud on two locations  800  at each stud thread crest  802  along an arc. In that way greater conductivity and reduced electrical resistance can be achieved at lower set screw torque settings than a standard thread connector.  
         [0045]     Turning now to  FIG. 12 , there is shown a cross sectional drawing of the external thread of stud  500 .  FIG. 12  depicts a cross sectional drawing of a section of external threads in accordance with an alternate embodiment of the present invention. There is shown stud  500  having a threaded portion  700 . The threads of threaded portion  700  have a threadform angle  405 , that is determined in accordance with the usual or customary threadform angle for threads of a particular size. In the example depicted, the treadform angle  405  is 60°+/−½°. The stud  500  threads  704  are comprised of two opposing flanks  1202  and  1204 , which converge to a peak  1206 . The peak  1206  being the uppermost point of the thread. In the exemplary thread  704  depicted, the peak  1206  of each thread does not converge at a single point, but instead the peak is truncated from the point of convergence. The amount that the peak is truncated is defined in relation to the height of the thread. The height (H)  1208  defined as the distance from the virtual point of convergence between flanks at the root  1208  to the virtual point of convergence at the peak  1206 . The peak in  FIG. 12  is truncated by a distance equal to H/8  1207 . The shortening of the peak produces surface  1214  that is parallel to the axis of the thread, wherein the longitudinal length is given as p/8  1209 . Furthermore, the virtual point of convergence of the root  1208  is also truncated by filling a portion of the valley  1218  at the convergence of the flanks. The valley is filled to a depth of H/4  1219 . The surface of the filled area is determined in accordance with standard dimensions for similarly sized threads, however it should be noted that the root  1208  can optionally be rounded during manufacturing, or may become rounded during usage. The stud  500  threads  704  therefore have a height from the truncated and rounded valley to the truncated peak, that is given by 17/24 H  1221 .  
         [0046]     Therefore, the thread pitch of stud  500  is longer than the corresponding valley pitch  1124  due to the due to the variation in thread pitch of connector  100  threads  112 . Furthermore, the depth of stud  500  threads from the truncated peak  1208  to the truncated valley  1208  is greater than the corresponding dimension of connector  100  threads  112 .  
         [0047]     It will be appreciated that the present invention has been described herein with reference to certain preferred or exemplary embodiments. The preferred or exemplary embodiments described herein may be modified, changed, added to, or deviated from without departing from the intent, spirit and scope of the present invention.