Patent Publication Number: US-9837743-B2

Title: Banana plug with raised break point

Description:
BACKGROUND ART 
     The banana plug is a commonly used device for making electrical connection with another device. Typically, a device, to which an electrical connection is desired, has a “female” banana jack formed therein. In order to make an electrical connection with the device, a “male” banana plug is inserted into the banana jack. Although banana plugs have existed for many years and are widely used, they are not without drawbacks. As the use of banana plugs becomes ubiquitous, banana plugs are now utilized outside of laboratory environments. Banana plugs are used with mobile testing devices, in harsh environments, are and subject to conditions for which they were not originally intended. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present technology and, together with the description, serve to explain the principles of the present technology. The drawings referred to in this description should not be understood as being drawn to scale except if specifically noted. 
         FIG. 1  shows a cut away perspective view of one embodiment of a banana plug with a raised break point in accordance with the present claimed invention. 
         FIG. 2  shows a perspective view of a banana plug with a raised break point in accordance with one embodiment of the present claimed invention. 
         FIG. 3  shows a partial cut away view of a center pin with a raised break point in accordance with one embodiment of the present claimed invention. 
       PRIOR ART  FIG. 4  shows a side view of a conventional center pin breaking off in a banana jack with a lowered break point. 
         FIG. 5  shows a side view of a center pin with a raised break point breaking off in a banana jack in accordance with one embodiment of the present claimed invention. 
         FIG. 6  shows a perspective view of a center pin having a cable conductor coupled thereto in accordance with the present claimed invention. 
         FIGS. 7A-7B  are cut away views of an inner component in accordance with the present claimed invention. 
         FIG. 8  is a perspective view of an inner component in accordance with the present claimed invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Reference will now be made in detail to various embodiments of the present technology, examples of which are illustrated in the accompanying drawings. While the present technology will be described in conjunction with these embodiments, it will be understood that they are not intended to limit the present technology to these embodiments. On the contrary, the present technology is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the present technology as defined by the appended claims. Furthermore, in the following description of the present technology, numerous specific details are set forth in order to provide a thorough understanding of the present technology. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present technology. 
     Overview 
     Embodiments in accordance with the present invention describe banana plug center pin with a raised break point. Embodiments in accordance with the present invention also describe a banana plug which includes the above described center pin such that the banana plug has a raised break point. As will be described below in detail, the raised break point ensures that should the banana plug break while inserted into a banana jack, the break point will be above the top edge of the banana jack. As such, the broken portion of the banana plug, residing in the banana jack, can be easily removed. Various embodiments of the present invention also describe novel features for improving the reliability of a banana plug. 
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1 , a cut away perspective view of one embodiment of a banana plug with a raised break point  100  in accordance with the present claimed invention is shown. Banana plug with raised break point  100  is comprised of various components. The present description will first briefly identify the various components, and then each of the components will be described below in detail. Banana plug with raised break point  100  includes a center pin  102 . As shown in  FIG. 1 , banana plug with raised break point  100  also includes a spring contact  120  which peripherally surrounds at least some of the bottom portion of center pin  102 . Banana plug with raised break point  100  also includes a cable conductor  130 . Cable conductor  130  has a first end electrically coupled to center pin  102 , and a second end extending into a cable jacket  136 . Banana plug with raised break point  100  further includes a crimped strain relief  140  having openings formed therein. As will be described below, in one embodiment, crimped strain relief  140  is compressed about cable jacket  136  such that cable jacket  136  bulges at least partially through the openings in crimped strain relief  140 . In one embodiment, banana plug with raised break point  100  also includes an inner component  150 . Inner component  150  encapsulates, in one embodiment, crimped strain relief  140 , cable conductor  130 , and a portion of center pin  102 . Referring still to  FIG. 1 , banana plug with raised break point  100  is at least partially encapsulated in an outer housing  150 . Finally, in one embodiment a pull tab  170  is coupled to outer housing  170 . Pull tab  170  provides a gripping portion for a user to, for example, extract banana plug with raised break point  100  from a banana jack, not shown. Referring briefly to  FIG. 2 , a perspective view of banana plug with raised break point  100  is provided. For purposes of clarity,  FIG. 2  shows banana plug with raised break point  100  without the cut away view details shown in  FIG. 1 . 
     Referring now to  FIG. 3 , a partial cut away view of center pin with a raised break point  102  in accordance with one embodiment of the present invention is shown. Importantly, and as will be described below, center pin  102  has a raised break point. That is, center pin  102  has a break point which is raised with respect to the break point associated with conventional center pins. As shown in  FIG. 3 , center pin  102  includes a top portion  104  and a bottom portion  106 . In the present embodiment, top portion  104  of center pin  102  has a diameter, D. Further, in the present embodiment, bottom portion  106  of center pin  102  has a diameter, d. In the present embodiment diameter D is greater than diameter d. The significance of the difference in diameters D and d will be discussed below in detail. Center pin having raised break point  102  further includes a locking ring  108 . In the present embodiment, locking ring  108  peripherally surrounds center pin  102  and is located at the interface of top portion  104  and bottom portion  106 . In various embodiments, center pin  102  may also include additional locking rings, such as, for example, locking ring  110 . Although, one additional locking ring  110  is shown in the present embodiment, the present invention is also well suited to embodiments in which center pin  102  includes more than one additional locking ring. 
     Referring still to  FIG. 3 , in the present embodiment, center pin  102  also includes a fillet feature  112 . As shown in  FIG. 3 , fillet feature  112  is coupled to bottom portion  106  and to locking ring  108  of center pin  102 . In one embodiment, fillet feature  112  is, for example a tapered bevel. 
     Referring now to Prior Art  FIG. 4 , a side view of a conventional center pin is shown inserted into a banana jack  400 . It should be noted that in Prior Art  FIG. 4 , various components of a banana plug are not shown for clarity. In Prior Art  FIG. 4 , it will be noted that banana jack  400  has a top surface denoted by dotted line  402 . During use, it is common for users to remove a banana plug from the banana jack into which it is inserted (e.g. banana jack  400 ), by pulling, for example, on the cord of the banana plug. In other instances, a user may simply pull the banana plug out of banana jack  400  at an angle, rather than pulling straight upward on the banana plug. For example, a user may pull on the banana plug at an angle as indicated by arrow  410 . When this occurs, the center pin of the banana plug is forced against the upper edge  404  of banana jack  400 . It should further be noted that conventional center pins have a uniform thickness T, along the entire length of the center pin. In conventional banana plugs, this causes the conventional center pin to break or snap off along line  402  of  FIG. 4 . When the conventional center pin breaks along line  402  as shown in Prior Art  FIG. 4 , it is often not possible for the user to extract the broken portion of the conventional center pin from banana jack  400 . This inability to extract the broken piece of the conventional center pin is depicted by the needle nose pliers  450  in the circle with a slash. In practice, the inability to remove broken portions of conventional center pins can result in downtime or servicing of a very expensive piece of equipment, merely to remove a portion of the conventional center pin. 
     Referring now to  FIG. 5 , a side view of a center pin  102  with a raised break point is shown inserted into a banana jack  400  in accordance with an embodiment of the present invention. With respect to  FIG. 5 , the present discussion will now describe, in detail, the beneficial raised break point of center pin  102  of the present invention. That is, the following discussion will describe how center pin  102  has a break point which is raised with respect to the break point associated with conventional center pins. It should be noted that in  FIG. 5 , various components of banana plug  100  are not shown for clarity. In  FIG. 5 , it will be noted that banana jack  400  has a top surface denoted by dotted line  402 . As mentioned above, during use, it is common for users to remove a banana plug from the banana jack into which it is inserted (e.g. banana jack  400 ), by pulling, for example, on cable jacket  136  of banana plug  100 . In other instances, a user may simply pull banana plug  100  out of banana jack  400  at an angle, rather than pulling straight upward on the banana plug. For example, a user may pull on the banana plug at an angle as indicated by arrow  510 . When this occurs, center pin  102  of banana plug  100  is forced against the upper edge  404  of banana jack  400 . 
     Referring still to  FIG. 5 , it should further be noted that center pin  102  of the present embodiment has a diameter, D, along top portion  104 , and a smaller diameter, d, along bottom portion  106 . In the present embodiment, the reduced diameter, d, of bottom portion  106 , allows center pin  102  to bend more freely than is found in a conventional center pin with a larger diameter. Further, by adding a fillet feature  112  which couples bottom portion  106  and locking ring  108 , forces (due to the angled ( 510 ) extraction of banana plug  100 ) are distributed along bottom portion  106 . That is, in the present embodiment, the reduced diameter of bottom portion  106  in combination with the addition of fillet feature  112  distributes extraction forces along bottom portion  108 . Also, the bending of center pin  102  (due to the reduced diameter of bottom portion  106 ) helps to reduce the accumulation of forces on center pin  102  along line  402 . Thus, rather than concentrating forces along line  402 , center pin  102  of the present embodiments allows extraction forces to be distributed along the length of bottom portion  106  and spread to the interface of top portion  104  and bottom portion  106 . As a result, should the forces exceed the breaking point of center pin  102 , in the present embodiments, center pin  102  will break at the interface of top portion  104  and bottom portion  106 . Hence, in the present embodiments, if center pin  102  breaks, it will do so above line  402  as shown in  FIG. 5 . As a result, it is easy for the user to extract the broken portion of center pin  102  from banana jack  400 . This ability to extract the broken piece of center pin  102  is depicted by the needle nose pliers  450  of  FIG. 5 . Hence, embodiments in accordance with the present invention eliminate significant expensive downtime and repairs associated with the use of conventional banana plugs. 
     Embodiments in accordance with the present invention realize additional structural integrity for banana plug  100 , of  FIG. 1 , through several novel mechanisms. For example, referring now to  FIG. 6 , a perspective view is shown of center pin  102  having cable conductor  130  coupled thereto. In the embodiment of  FIG. 6 , cable conductor has a first end  132  electrically coupled to center pin  102 , and a second end, hidden, extending into a cable jacket  136 . In the present embodiment, banana plug with raised break point  100  further includes a crimped strain relief  140  having openings typically shown as  142  formed therein. In one embodiment, crimped strain relief  140  is compressed about cable jacket  136  with sufficient force such that a portion of cable jacket  136  bulges at least partially through openings  142  in crimped strain relief  140 . As a result, a bump  144  of cable jacket  136  is created. Bump  144  of cable jacket  136  provides an additional adhesion point for the inner component, not shown in  FIG. 6 . 
     Referring now to  FIG. 7A , a cut away view of inner component  150  is shown. In  FIG. 7A , center pin  102  is shown disposed within inner component  150 .  FIG. 7A  clearly shows a recessed region  702  for receiving cable conductor  130 , including first end  132 . Additionally, recessed region  702  of inner component  150  is formed to receive cable jacket  136  and crimped strain relief  140 . Inner component  150  further has an indent  704  for receiving bump  144  of cable conductor  136 . Importantly, various features on center pin  102  prevent movement of center pin  102  with respect to inner component  150 . Specifically, locking features  108  and  110  provide numerous hard chine points to ensure that center pin  102  does not move with respect to inner component  150 . In addition, in various embodiments, locking features  108  and  110  have a “flat” (typically shown as  115 ) or non-curved surface formed thereon. Flat  115  helps to prevent rotational movement of center pin  102  with respect to inner component  150 . As a result, embodiments in accordance with the present invention include features to prevent motion in all directions with respect to inner component  150 . 
       FIG. 7B  provides a cut away view of inner component  150  with cable jacket  136  and crimped strain relief  140  (with bump  144 ) disposed in recessed  702 . Inner component  150  provides several significant advantages to banana plug  100  of the present embodiments. First, in various embodiments, inner component  150  prevents movement of various elements or components with respect to outer housing  160 . That is, as depicted in  FIGS. 7A and 7B , inner component  150  encapsulates components such as for example center pin  102 . In various embodiments, inner component  150  is made of a material having a hardness which is greater than that of outer housing  160 . By encapsulating the components with a harder material than that of outer housing  160 , inner component  150  increases the rigidity of banana plug  100 . See  FIG. 8 , in which a perspective view is shown of inner component  150 . Once inner component  150  is encapsulated by outer housing  160 , a rigid banana plug is achieved. The ruggedized nature of the present banana plug  100  further prevents bending of center pin  102  during use of banana plug  102 . 
     Referring to  FIG. 8 , in various embodiments, inner component  150  also includes protrusions  802 ,  804 ,  806 , and  808 . Protrusions  802  and  804  are configured to prevent vertical (i.e. up and down) movement of inner component  150  with respect to outer housing  160  of  FIG. 1 . Similarly, protrusions  806  and  808  are configured to prevent horizontal movement of inner component  150  with respect to outer housing  160 . As a result, in various embodiments, the retention of components within inner component  150 , coupled with the restriction of movement of inner component  150  with respect to outer housing  160 , ensures that banana plug  100  achieves a rigidity not found in conventional banana plugs. 
     Further, embodiments in accordance with the present invention are well suited to use in numerous environments and present embodiments are not limited to any one single application. 
     Although the subject matter is described in a language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.