Abstract:
An apparatus for locking a plug for use with a plug and a plug signal receptacle for prevention of intentional or inadvertent removal of a plug.

Description:
STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor. 
    
    
     BACKGROUND 
     The present invention relates to an apparatus for locking a plug. More specifically, but without limitation, the present invention relates to an apparatus for locking an audio headphone plug. 
     Current plug signal receptacles do not securely lock plugs in place to prevent unauthorized or accidental removal. Often plugs are inadvertently or intentionally removed by unauthorized personnel. Removal of plugs could cause disruption of service that is being provided by the plugs (service could include, but without limitation, audio and/or video feed). 
     Furthermore, plugs and their respective attachments are often stolen, specifically, but without limitation, if audio headphones are to be used by the public in a public venue such as a concert hall, sports arena, or mall kiosk. Because of this high probability of theft, public venues often do not offer audio headphones, and typically have all announcements broadcast over a loudspeaker system that is often inaudible or difficult to understand. Having a mechanism that could secure plugs, specifically headphone plugs, venues could offer additional services, such as for example, but without limitations, clear play-by-play announcements at sporting events or enhanced sound at concerts. 
     Thus, there is a need in the art to provide a method or mechanism that incorporates the listed benefits without the limitations inherent in present methods. For the foregoing reasons, there is a need for an apparatus for locking a plug. 
     SUMMARY 
     The instant invention is directed to an apparatus for locking a plug, specifically an apparatus for use with a plug and a plug signal receptacle. The apparatus for locking a plug includes a plug lock, a plug lock spring, a locking release mechanism, and a plug lock locking mechanism. The plug lock is rotatably secured about a first selected point or axis, and the plug lock rotates about the first selected point or axis as the plug enters the plug signal receptacle. The plug lock communicates with the plug lock spring such that the plug lock spring applies force on the plug lock such that the plug lock returns to a neutral position after the plug is fully engaged in the plug signal receptacle. The neutral position being the position where the plug lock is substantially perpendicular to the plug signal receptacle. The locking release mechanism is rotatably secured about a second selected point or axis; the locking release mechanism communicates with the plug lock such that when the plug lock rotates about the first selected point or axis the locking release mechanism rotates about the second selected point or axis. The plug lock locking mechanism communicates with the locking release mechanism such that when the locking release mechanism rotates about the second selected point or axis the plug lock locking mechanism secures the plug lock in the neutral position, and the plug lock then retains and holds the plug securely in the plug signal receptacle. 
     The present invention is directed to an apparatus for locking a plug that can secure a plug in its respective plug signal receptacle. 
     The present invention is directed to an apparatus for locking a plug that prevents inadvertent or intentional removal by unauthorized personnel. 
     It is an object of the invention to provide an apparatus for locking a plug that can allow a venue to provide additional audio (or video) services via a secured headphone system. 
    
    
     DRAWINGS 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims, and accompanying drawings wherein: 
     FIG. 1 is an internal side view of an embodiment of the apparatus for locking a plug; 
     FIG. 2 is an internal side view of an embodiment of the apparatus for locking a plug with the plug partially entering the plug receptacle; 
     FIG. 3 is an internal side view of an embodiment of the apparatus for locking a plug with the plug fully engaged in the plug receptacle; and 
     FIG. 4 is an internal side view of an embodiment of the apparatus for locking a plug. 
    
    
     DESCRIPTION 
     The preferred embodiments of the present invention are illustrated by way of example below and in FIGS. 1-4. The apparatus for locking a plug  1  is for use with a plug  10  and a plug signal receptacle  20  (and/or plug signal receptacle housing  25 ). Typically, plugs  10  have a substantially circular cross section and the plug signal receptacle  20  has a corresponding shape in order to accept the plug  10 . Also, in a typical plug-receptacle configuration when the plug  10  is fully inserted in the plug signal receptacle  20  both the plug  10  and plug signal receptacle  20  are substantially axially aligned. The plugs  10  may be headphone plugs or audio headphone signal plugs  15  attached to a headphone  16 , while the plug signal receptacle  20  may be an audio signal receptacle or a headphone plug signal receptacle  21 . As seen in FIGS. 2 and 3, the standard plug  10  typically has a truncated conic section tip  11 , with an indentation  12  just past the end of the truncated conic section tip  11 . The indentation  12  is typically disposed around the entire cross section of the plug  10 . The remaining portion of the plug  10  is typically a shaft  13  and an end portion  14  having a larger cross section than the shaft  13 . The end portion  14  and the truncated conic sect tip  11  are typically on opposite ends of the shaft  13 . 
     In the discussion of the present invention, the invention will be discussed in an audio headphone environment; however, this invention can be utilized for any type of need that requires a plug lock, specifically, but without limitation, in audio, video or any type of electronic feed that requires a plug lock. 
     As seen in FIG. 1, the apparatus for locking a plug  1  includes a plug lock  100 , a plug lock spring  200 , a locking release mechanism  300 , and a plug lock locking mechanism  400 . The plug lock  100  is rotatably secured about a first selected point or axis  101 . In operation, as s en in FIG. 2, the plug lock  100  rotates about the first selected point or axis  101  as the plug  10  (or headphone plug  15 ) enters the plug signal receptacle  20  (or audio signal receptacle  21 ). The plug lock spring  200  communicates with the plug lock  100  such that the plug lock spring  200  applies force on the plug lock  100  such that the plug lock  100  returns to a neutral position after the plug  10  is fully engaged in the plug signal receptacle  20 . The neutral position, as shown in FIGS. 1,  3  and  4 , may be defined, but without limitation, as the position where the plug lock  100  is substantially perpendicular to the plug signal receptacle  20  or the plug  10  itself. The locking release mechanism  300  is rotatably secured about a second selected point or axis  301 . The locking release mechanism  300  communicates with the plug lock  100  such that when the plug lock  100  rotates about the first selected point or axis  101  the locking release mechanism  300  rotates about the second selected point or axis  301 . The plug lock locking mechanism  400  communicates with the locking release mechanism  300  such that when the locking release mechanism  300  rotates about the second selected point or axis  301  the plug lock locking mechanism  400  secures the plug lock  100  in the neutral position, and the plug lock  100  then retains and holds the plug  10  securely in the plug signal receptacle  20 . 
     As seen in FIGS. 1-4, the plug lock  100  may include a plug lock boss  105  and a plug lock spring portion  110 . The plug lock boss  105  may have first plug lock boss portion  106  and a second plug lock boss portion  107 . The first plug lock boss portion  106  may correspond to the indentation  12  of the plug  10 . The second plug lock boss portion  107  may have a notch  108  that corresponds to the plug lock locking mechanism  400  and allows the plug lock locking mechanism  400  to lock and secure the first plug lock boss portion  106  in the indentation  12  when the plug  10  is fully inserted in the plug signal receptacle  20 . The plug lock spring portion  110  is attached to the second plug lock boss portion  107  on the opposite side of the notch  108 . The plug lock spring portion  110  may be rotatably attached to the first selected point or axis  101  and communicates with the plug lock spring  200 . As seen in FIG. 1, the plug lock boss  105  and the plug lock spring portion  110  may be perpendicular to each other and form a L-shape. The plug lock spring portion  110  may include a first plug lock spring end portion  111  and a second plug lock spring end portion  112 . The fist plug lock spring end portion  111  may be rounded while the second plug lock spring end portion  112  may be attached to the second plug lock boss portion  107 . In the fully inserted position, the plug lock  100  may envelope all or a portion of the indentation  12 . The plug lock  100  may also have various detents located throughout the first plug lock boss portion  106 . 
     As seen in FIG. 1, the locking release mechanism  300  may include a plug lock arm  305 , a locking release mechanism arm  310 , a locking release mechanism main member  315 , and a locking release mechanism spring  320 . The plug lock arm  305  and the locking release mechanism arm  310  may be located on opposite en of the locking release mechanism main member  315 . Both the plug lock arm  305  and the locking release mechanism arm  310  may be pivotally attached to the locking release mechanism main member  315 . The plug lock arm  305  may include a first plug lock arm end portion  306  and a second plug lock arm end portion  307 . The first plug lock arm end portion  306  may have a fluke or have substantially a triangular shape. In the preferred embodiment, as seen in FIG. 1 the first plug lock arm end portion  306  communicates with the second plug lock boss portion  107 , while the second plug lock arm end portion  307  is pivotally or rotatably attached to the locking release mechanism main member  315 . The locking release mechanism arm  310  may include a fast locking release mechanism arm and portion  311  and a second locking release mechanism arm end portion  312 . In one of the embodiments, as seen in FIG. 1, the fist locking release mechanism arm end portion  311  communicates with the plug lock locking mechanism  400 , while the second locking release mechanism arm end portion  312  is pivotally or rotatably attached to the locking release mechanism main member  315 . The locking release mechanism spring  320  may also communicate with the second locking release mechanism arm end portion  312  and/or the locking release mechanism main member  315 . As seen in FIGS. 1 and 2, the first locking release mechanism arm end portion  311  may also rotate about a third selected point or axis  302 . 
     In one of the embodiments of the invention, the apparatus for locking a plug  10  may include two or more plug locks  100 , two or more plug lock springs  200 , and two or more locking release mechanisms  300 . When utilizing two of each element, the two plug locks  100  may be disposed on opposite sides of the plug signal receptacle  20 . 
     The plug lock locking mechanism  400  may include a plug lock locking mechanism arm  405 , a plug lock locking mechanism base  410  and a plug lock locking mechanism spring  415 . Tre plug lock locking mechanism arm  405  may include a first plug lock locking mechanism arm end portion  406  and a second plug lock locking mechanism arm end portion  407 . The first plug lock locking mechanism arm end portion  406  corresponds to the notch  108  in the second plug lock boss portion  107 . The second plug lock locking mechanism arm end portion  407  is attached to the plug lock locking mechanism base  410 . The plug lock locking mechanism base  410  communicates with the plug lock looking mechanism spring  415 . The plug lock locking mechanism arm  405  may also include a gain  408 . The gain  408  may be larger than the cross section of the first locking release mechanism arm end portion  311 . The first locking release mechanism arm end portion  311  or a portion thereof may be disposed within the gain  408 . As see n in FIG. 1, in the neutral position without a plug  10  fully engaged in the plug signal receptacle  20 , the locking release mechanism spring  320  exerts force upon the locking release mechanism arm  310  causing the bottom of the first locking release mechanism arm end portion  311  to press on the lower portion of the gain  408 , opposing the force of the plug lock locking mechanism spring  415 . 
     The plug lock spring  200  and/or the locking release mechanism spring  320  and/or the plug lock locking mechanism spring  415  may be an extension, compression, die, torsion, Belleville disc or any other type of spring. The springs ( 200 ,  320 ,  415 ) may be manufactured from high-carbon steel, stainless steel, a nonferrous alloy, brass, or any material that lends itself to the manufacture of a spring. 
     The apparatus for locking a plug  10  may also include an electromagnet  500 . The electromagnet  500  magnetically communicates with the plug lock locking mechanism  400  such that when the electromagnet  500  is activated the plug lock locking mechanism  400  is attracted to the electromagnet and the plug lock  100  no longer retains and holds the plug  10  securely in the plug signal receptacle  20 . In one of the preferred embodiments there are two electromagnets  500  located on opposite ends of the plug lock locking mechanism base  410 . 
     In operation, in the preferred embodiment, as seen in FIG. 2, when the plug  10  enters the plug signal receptacle  20 , the truncated conic section tip  11  presses against the plug lock boss  105  which casses the plug lock  100  to rotate or pivot about the first selected point or axis  101 . The second plug lock boss portion  107  presses against the tip of first plug lock arm end portion  306 , causing the plug lock arm  305  and the locking release mechanism arm  310  to rotate or pivot about the second selected point or axis  301  and the third selected point or axis  302 . As seen in FIG. 3 this then allows the plug lock locking mechanism  400  to go upward due to the plug lock locking mechanism spring  415  and the bottom of the first locking release mechanism arm end portion  311  no longer pressing on the lower portion of the gain  408 , and opposing the force of the plug lock locking mechanism spring  415 . As the plug  10  is fully engaged, the plug lock spring  200  then pushes the first plug lock boss portion  106  into the indentation  12 . At or about the same time the first plug lock locking mechanism arm end portion  406  enters into the notch  108  locking the plug  10  into the plug signal receptacle  20 . In order to unlock the plug  10  from the plug signal receptacle  20  the electromagnets  500  are activated, and then the electromagnets  500  pull the first plug lock locking mechanism arm end portion  406  away from the notch  108 . 
     In one of the embodiments, there are two locking release mechanism springs  320  located at opposite side portions of the locking release mechanism arm  310 . However, multiple springs may be used. In the preferred embodiment, the total tensile strength of the locking release mechanism springs  320  equals the tensile strength of plug lock locking mechanism spring  415  and the total tensile strength of the electromagnet  500  must be twice that of plug lock locking mechanism spring  415 . 
     When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a,” “an,” “the,” and “said” are intended to mean there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.