Patent Publication Number: US-6222506-B1

Title: Transmitting and receiving antenna for animal training devices

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates, in general, to a transmitting and receiving antenna for animal training devices and, more particularly, to a transmitting and receiving antenna attached to a transceiver for animal training devices and used for transmitting and receiving signals of a specific frequency band. 
     2. Description of the Prior Art 
     A conventional transmitting and receiving antenna, which is usable with animal training devices, is shown in FIG.  1 . As shown in the drawing, the conventional antenna for animal training devices comprises a stud bolt  7 , which consists of a hexagonal body  1 , an externally-threaded connector  3  and a support projection rod  5 . The hexagonal body  1  has a hexagonal cross-section, with the externally-threaded connector  3  extending from one end of the body  1  and the support projection rod  5  extending from the other end of the body  1 . A flexible coil spring  9  is fitted over the stud bolt  7  and is fixed to the bolt  7  through a soldering process. A longitudinal rod  11 , made of glass fiber, is inserted into the outside end of the coil spring  9 . A loading coil  13  is fixed to the coil spring  9  at one end thereof through a soldering process and is coiled around the longitudinal rod  11 . The antenna also has a protection cover  15 , which is assembled with the hexagonal body  1  of the stud bolt  7  so as to cover both the coil spring  9  and the loading coil  13  wound around the longitudinal rod  11 . This protection cover  15  thus protects both the coil spring  9  and the loading coil  13 . 
     In such a conventional transmitting and receiving antenna, it is necessary to use a flexible coil spring  9 , which is formed by regularly coiling a copper-plated flexible steel wire at a predetermined pitch, so as to allow the antenna to elastically maintain its desired straight shape while being free from being cut or bent when the antenna is unconsciously caught by an obstacle. Due to such a flexible coil spring  9 , it is impossible to reduce the length of the antenna to a desired short length. This finally forces the antenna to have such an awkward length that the antenna is inconvenient to a user while carrying or using it. 
     In addition, it is necessary to cut a length of the distal end of the loading coil  13 , wound around the longitudinal rod  11  made of glass fiber, in order to set a specific frequency band and to allow the antenna to transmit and receive signals of such specific frequency band. It is thus very difficult to precisely or finely control the frequency band of signals to be transmitted and received by the antenna. When an exceeding length of the loading coil  13  is unconsciously cut while setting a specific frequency band of signals to be transmitted and received by the antenna, it is impossible for a resulting antenna to transmit or receive signals of the specific frequency band. This finally reduces the operational reliability of such antennae. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a transmitting and receiving antenna for animal training devices, which is convenient to a user while carrying and using it. 
     Another object of the present invention is to provide a transmitting and receiving antenna for animal training devices, which is designed to easily set a desired specific frequency band of signals to be transmitted and received by the antenna. 
     A further object of the present invention is to provide a transmitting and receiving antenna for animal training devices, which is improved in production yield. 
     Still another object of the present invention is to provide a transmitting and receiving antenna for animal training devices, which has a desired short length. 
     In order to accomplish the above object, the present invention provides a transmitting and receiving antenna for animal training devices, comprising: a stud bolt consisting of a hexagonal body, with an externally-threaded connector and an internally-threaded bushing provided at opposite ends of the hexagonal body; a cylindrical bobbin having an externally-threaded part at a first end thereof and assembled with the internally-threaded bushing of the stud bolt at the externally-threaded part through a screw-type engagement, with an internally-threaded hole being axially formed on a second end of the bobbin and being used for setting a desired specific frequency band of signals to be transmitted and received by the antenna, and a radial hole being formed on the bobbin at a position around the externally-threaded part in a way such that the radial hole is perpendicular to a central axis of the bobbin; a helical coil inserted into the radial hole of the bobbin at one end thereof so as to be fixed to the stud bolt at the end through a soldering process, the helical coil being regularly, densely and spirally coiled around the bobbin; a core movably engaging with the internally-threaded hole of the bobbin through a screw-type engagement and used for precisely and finely setting the desired specific frequency band of signals; and a protection cover removably assembled with the hexagonal body of the stud bolt so as to cover and protect both the core and the helical coil, the protection cover having a longitudinal cavity designed to receive both the core and the helical coil therein, with a hexagonal fitting mouth communicating with the cavity and being formed at an end of the protection cover so as to be fitted over the hexagonal body of the stud bolt. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is an exploded perspective view of a conventional transmitting and receiving antenna for animal training devices; 
     FIG. 2 is a perspective view, showing an appearance of a transmitting and receiving antenna for animal training devices in accordance with the preferred embodiment of the present invention; 
     FIG. 3 is an exploded perspective view of the antenna of FIG. 2; 
     FIG. 4 is a sectional view of the antenna of this invention taken along the line IV—IV of FIG. 3; 
     FIG. 5 is a sectional view of the antenna of this invention taken along the line V—V of FIG. 3; and 
     FIG. 6 is a sectional view of the antenna of this invention taken along the line VI—VI of FIG.  2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 2 is a perspective view, showing an appearance of a transmitting and receiving antenna for animal training devices in accordance with the preferred embodiment of this invention. FIG. 3 is an exploded perspective view of the antenna of FIG.  2 . FIG. 4 is a sectional view of the antenna of this invention taken along the line IV—IV of FIG.  3 . FIG. 5 is a sectional view of the antenna of this invention taken along the line V—V of FIG.  3 . FIG. 6 is a sectional view of the antenna of this invention taken along the line VI—VI of FIG.  2 . 
     As shown in FIGS. 2 to  6 , the transmitting and receiving antenna for animal training devices according to the preferred embodiment of this invention comprises a stud bolt  107 , which consists of a hexagonal body  100  and an externally-threaded connector  103 . The hexagonal body  100  has a hexagonal cross-section, with the externally-threaded connector  103  extending from one end of the body  100  and an internally-threaded bushing  105  extending from the other end of the body  100 . A cylindrical bobbin  113  is assembled with the internally-threaded bushing  105  of the hexagonal body  100  at its externally-threaded part  109  through a screw-type engagement. The cylindrical bobbin  113  has the externally-threaded part  109  at one end thereof, with an internally-threaded hole  111  being axially formed on the other end of the bobbin  113  and being used for setting a desired specific frequency band of signals to be transmitted and received by the antenna. The above bobbin  113  also has a radial hole  112 , which is formed at a position around the externally-threaded part  109  in a way such that the radial hole  112  is perpendicular to the central axis of the bobbin  113 . A helical coil  115  is inserted into the radial hole  112  of the bobbin  113  at one end thereof prior to being fixed to the stud bolt  107  through a soldering process. The above helical coil  115  is regularly, densely and spirally coiled around the bobbin  113  so as to reach a position around the end having the internally-threaded hole  111 . A core  117  engages with the internally-threaded hole  111  of the bobbin  113  through a screw-type engagement and is used for precisely and finely setting a desired specific frequency band of signals to be transmitted and received by the antenna. The antenna of this invention also has a protection cover  121 , which is assembled with the hexagonal body  100  of the stud bolt  107  so as to cover both the core  117  and the helical coil  115  wound around the bobbin  113 . This protection cover  121  thus protects both the helical coil  115  and the core  117 . The above protection cover  121  has a longitudinal cavity  118  designed to receive both the helical coil  115  and the core  117  therein. A hexagonal fitting mouth  119 , communicating with the cavity  118 , is formed at the end of the protection cover  121  and is fitted over the hexagonal body  100  of the stud bolt  107 . 
     In the antenna of this invention, the bobbin  113  is preferably made of Teflon or a ferrite material, having a high degree of permeability and a high degree of formability. In the case of a Teflon bobbin  113 , it is possible to directly and densely wind the helical coil  115  around the bobbin  113  without interposing an insulator between the bobbin  113  and the coil  115 . However, in the case of a ferrite bobbin  113 , it is preferable to densely wind the coil  115  around the bobbin  113 , with an insulating paper being completely wrapped around the bobbin  113  so as to accomplish a desired electronic insulation effect between the bobbin  113  and the coil  115 . Of course, it should be understood that it is possible to wind the coil  115  around such a ferrite bobbin  113  without wrapping an insulating paper on the bobbin  113 . 
     As shown in FIG. 4, it is preferable to set the number of turns of the helical coil  115  wound around the bobbin  113  to 200 to 250 turns, which allows the coil  115  to be densely coiled with each turn of the coil  115  to be brought into contact with neighboring turns. In the present invention, an enameled wire is preferably used as the material of the helical coil  115 . Of course, it should be understood that the number of turns of the helical coil  115  is changed in accordance with a desired frequency band of signals to be transmitted and received by the antenna. 
     The above protection cover  121  is made through a plastic injection molding process. In order to accomplish a firm engagement of the cover  121  with the hexagonal body  100  of the stud bolt  107 , two longitudinal fitting grooves  101  are axially formed on the external surface of the body  100  at diametrically opposite positions, with two longitudinal fitting rails  120  being axially formed on the internal surface of the hexagonal fitting mouth  119  of the cover  121  at diametrically opposite positions and engaging with the two fitting grooves  101 . A plurality of axial projections  123  are regularly formed on the external surface of the cover  121  at a portion around the mouth  119 , allowing a user to easily rotate the stud bolt  107  when the antenna is integrated with a transceiver (not shown) by bringing the externally-threaded connector  103  of the stud bolt  107  into a screw-type engagement with an internally-threaded part of the transceiver. 
     In the present invention, it is preferable to use a tapping screw or a screw bolt, made of stainless steel or ferrite, as the core  117 . 
     The process of producing the above antenna and operational effect of the antenna will be described hereinbelow. 
     In order to produce an antenna of this invention, a cylindrical bobbin  113  is fixed to the winding shaft of a winder (not shown) prior to inserting one end of an enameled wire into the radial hole  112 , which is formed on the bobbin  113  at a position around the externally-threaded part  109 . Thereafter, the winder is turned on, thus allowing the enameled wire to be regularly, densely and spirally coiled around the bobbin  113  and to form a single-layered helical coil  115  as shown in FIG.  4 . 
     In order to prevent the helical coil  115  from being undesirably loosened on the bobbin  113 , an instantaneous bonding agent is dropped onto an area of 1-5 mm width at each end of the coil  115 , thus instantaneously bonding opposite end areas of the coil  115  to the bobbin  113 . 
     Thereafter, the externally-threaded part  109  of the bobbin  113  is brought into screw-type engagement with the internally-threaded bushing  105  of the stud bolt  107 , thus assembling the bobbin  113  with the stud bolt  107  into a single structure. After assembling the bobbin  113  with the stud bolt  107 , the end of the helical coil  115 , inserted into the radial hole  112  of the bobbin  113 , is fixed to the stud bolt  107  through a soldering process. In such a case, it is preferable to apply a bonding agent to the junction between the externally-threaded part  109  of the bobbin  113  and the internally-threaded bushing  105  of the stud bolt  107  while assembling the bobbin  113  with the stud bolt  107 , thus accomplishing a firm engagement between the two threaded parts  105  and  109 . 
     Thereafter, a core  117  is appropriately threaded into the internally-threaded hole  111  of the bobbin  113  so as to set a specific frequency band of signals to be transmitted and received by the antenna. After setting a desired specific frequency band of signals by controllably threading the core  117  into the hole  111  of the bobbin  113 , the protection cover  121  engages with the stud bolt  107  by fitting the hexagonal fitting mouth  119  of the cover  121  over the hexagonal body  100  of the stud bolt  107 . When the hexagonal fitting mouth  119  of the cover  121  is fitted over the hexagonal body  100  of the stud bolt  107 , the two longitudinal fitting rails  120  of the hexagonal fitting mouth  119  engage with the two fitting grooves  101  of the hexagonal body  100 , thus accomplishing a firm engagement of the cover  121  with the stud bolt  107 . 
     In such a case, the axial projections  123  are regularly formed on the external surface of the protection cover  121 , and so it is possible to easily insert the hexagonal body  100  of the stud bolt  107  into the mouth  119  of the cover  121 . The above axial projections  123  of the protection cover  121  also allow a user to easily rotate the stud bolt  107  when the resulting antenna is integrated with a transceiver (not shown) by bringing the externally-threaded connector  103  of the stud bolt  107  into a screw-type engagement with an internally-threaded part of the transceiver. 
     When it is necessary to change the preset frequency band of the antenna, the protection cover  121  is primarily removed from the stud bolt  107 . Thereafter, the core  117  is appropriately rotated clockwise or counterclockwise relative to the bobbin  113  until a newly desired frequency band is accomplished. Therefore, it is very easy for a user of this antenna to set or change the frequency band of signals to be transmitted or received by the antenna. 
     The transmitting and receiving antenna for animal training devices according to this invention is thus free from using a conventional coil spring, but uses a bobbin  113  made of Teflon or a ferrite material, which has a high degree of permeability and a high degree of formability. Therefore, it is possible to preferably reduce the length of the antenna, and so the antenna of this invention is very convenient to a user while carrying or using it. In addition, a desired frequency band of signals to be transmitted and received by the antenna is easily and precisely set by appropriately rotating the core  117  relative to the internally-threaded hole  111  of the bobbin  113 . This finally allows resulting antennae to have improved and uniform quality in addition to an improved operational reliability. The production yield of such antennae is thus remarkably improved. 
     As described above, the present invention provides a transmitting and receiving antenna for animal training devices. In this antenna, a helical coil, made of enameled wire, is densely wound around a cylindrical bobbin made of Teflon or a ferrite material. Opposite end portions of the above helical coil are bonded to the bobbin using a bonding agent so as to be free from being undesirably loosened from the bobbin. A core, used for allowing a user to control a desired specific frequency band of signals to be transmitted and received by the antenna, is movably threaded into an internally-threaded hole formed at the end of the bobbin. The above bobbin is assembled with an internally-threaded bushing of a stud bolt at its externally-threaded part through a screw-type engagement. One end of the helical coil is fixed to the stud bolt through a soldering process. In the antenna of this invention, all the hexagonal body of the stud bolt, the helical coil and the core are covered with a protection cover, thus being protected from external impact. Due to the structure of the core movably threaded into the internally-threaded hole of the bobbin, it is easy for a user to precisely and finely set or change a desired frequency band of signals by appropriately rotating the core relative to the internally-threaded hole of the bobbin. This also results in an improved production yield of such antennae. The antenna of this invention is free from using a conventional coil spring, thus preferably having a desired short length. This antenna is thus convenient to a user while carrying or using it. 
     Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.