Abstract:
A method and device helps to prevent theft of sonar devices and GPS units from the brackets they are normally installed on or mounted to. The present invention provides for a unique locking device having a threaded end. The locking device is capable of alternatively permitting and prohibiting rotation of the threaded end. When a key is turned to lock the device, the handle of the device is permitted to rotate freely and the device does not permit rotation and removal of the threaded end. The device also provides for a hardened spacer that directly abuts the handle such that it prevents a thief from getting access to, and thus cutting the threaded end of the locking device.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to locks and other security devices. More specifically, it relates to a device and method that is used to secure an electronic instrument to a bracket by replacing a threaded mounting portion of the instrument or of the bracket with a lock mechanism.  
       BACKGROUND OF THE INVENTION  
       [0002]     There are many types of electronic instruments, all of them being relatively expensive, such as marine sonar devices, global positioning devices (GPS), among others, that are designed with threaded holes in opposed sides of the body of the instrument. Normally, these instruments are installed between a U-shaped bracket having circular openings or slots aligned with threaded holes of the instrument. A pair of screws or threaded rods or even handles having threaded ends are used to secure the sonar unit, or GPS, to the bracket. This mounting system allows the instrument to be pivoted to any desired angle for viewing. The addition of slots to the bracket also permits some vertical adjustability in addition to this angular adjustability. Obviously, by tightening the screws, or threaded rods, one can secure both the vertical position of the device and its angle of tilt. In this inventor&#39;s experience, boaters prefer electronic instruments such as sonar to be raised off the console so they are more readily visible from a standing position, such as when the driver of the boat is standing at the wheel for better visibility.  
         [0003]     Frequently, a ball mount stand is used so that the instrument can be raised and lowered and adjusted infinitely between a fully raised or lowered position. The ball mount stand uses clamping pressure applied by a threaded rod having a handle on it. The stand itself is nothing more than a clamshell design. One end of the clamshell is placed over a ball that is permanently affixed to a surface, such as a console. The other end of the clamshell is placed over a ball that is mounted to the underside of the instrument. The threaded rod is then inserted through threaded apertures in the clamshell design and tightened to the point that the stand maintains its position over the console.  
         [0004]     Unfortunately, as easily and conveniently as the aforementioned mounting devices are to install, it is equally as easily to remove them. The valuable nature of GPS units and marine sonar units also makes them an easy potential target for thieves.  
       SUMMARY OF THE INVENTION  
       [0005]     What is needed is a method and device for securely and inexpensively locking instruments to brackets. The present invention provides such a method and device that, when used properly, helps to prevent theft of sonar devices and GPS units from the brackets they are normally installed on or mounted to. The present invention provides for a unique locking device having a threaded end. This unique locking device is capable of alternatively permitting and prohibiting rotation of the threaded end. Thus, when a key is turned to lock the device, the handle of the device is permitted to rotate freely and the device does not permit rotation and removal of the threaded end. Furthermore, in the event the potential thief is undeterred, the present invention also provides for a hardened spacer that directly abuts the handle such that prevents a thief from getting access to, and thus cutting the threaded end of the locking device. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a perspective view of the locking device of the present invention as it is used with an electronic instrument mounted to and enclosed in a U-shaped bracket.  
         [0007]      FIG. 2  is an exploded perspective view of the device shown in  FIG. 1 .  
         [0008]      FIG. 3  is a perspective view of the present invention as it would be used with an adjustable ball mount for the instrument. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0009]     Referring now to the drawings in detail, wherein like numbered elements correspond to like elements throughout,  FIG. 1  is a perspective view showing the locking device, generally identified  10 , associated with the present invention as it is used with a marine sonar unit I mounted on a U-shaped bracket  5 . As shown, the sonar unit  1  includes a display  2  which must be observable by the user. The U-shaped bracket  5  includes a central bracket portion  8  and a pair of upwardly extending bracket arms  6 ,  7 . The U-shaped bracket  5  is then typically permanently affixed to some sort of console  9  by means of fasteners  3  and in full view of the operator of the vessel.  
         [0010]      FIG. 2  is a perspective view showing the detailed structure of the locking device  10  employed in the present invention.  FIG. 3  is yet another illustration of the special utility of the method and device of the present invention. In this view, the locking device  10  is used to join a different type of mounting system wherein a ball mount assembly  100  is used.  
         [0011]     Referring again to  FIG. 2 , a handle  20  having a threaded end (not shown) is normally used to attach the instrument  1  to the U-shaped bracket  5 . As discussed above, while this type of handle  20  is convenient for boat owners, it is also convenient for thieves. Therefore, as shown in  FIG. 1 , the present invention provides for a locking device  10  to deter such thieves.  
         [0012]     In general, the device of the present invention is comprised of a key  90 , a lock cylinder  80 , housing  70 , bolt  60 , interlock  50 , housing end  40 , and a protective sheath assembly  30 . The protective sheath assembly  30  is comprised of a rubber washer  31 , a hardened bushing  33  and a large spacer  35 . The rubber washer  31  includes a central aperture  32  and the bushing  33  also includes a central aperture  34 . The apertures  32 ,  34  are provided to allow passage of a portion of a bolt  60  through the washer  31  and the bushing  33 , respectively. This protective sheath assembly  30  permits rotation of a bolt  60  that passes through the assembly  30  in addition to providing a layer of protection around the bolt  60 . That is, the lock device  10  itself does little good unless the bolt  60  is protected. Thieves who would formerly have simply unscrewed the threaded handle  20  to either side of the instrument  1  could simply cut the bolt  60  were it not protected. Therefore, the present invention provides the large spacer  35 . The spacer  35  is preferably made of a hardened, shatter resistant, durable material. A first side (not shown) of the spacer  35  is sloped concavely inward towards the center of the spacer  35 . The concavity of this side of the spacer  35  is designed to reflect the curvature of the housing end  40  of the locking device  10 . In this manner, when the lock is tightened, a potential thief is not able to insert a prying or cutting mechanism between the large spacer  35  and the housing end  40 .  
         [0013]     The second side  37  of the spacer  35  features a central aperture  36 , a recessed area  38  and a ledge  39 . The central aperture  36  is situated toward the interior of the spacer  35  and Is functionally adapted to surround the spacer  33 . The recessed area  38  permits use of the rubber washer  31  between the spacer  35  and the bracket arm  6 . Normally, the rubber washer  31  is slightly thicker than the recessed area  38  of the spacer  35  is deep. This permits the installer to tighten down the bolt  60  until the ledge  39  of the spacer  35  is flush against the bracket arm  6 . It is important to have the rubber washer  31  flush against the bracket arm  6  to reduce vibration. The rubber washer  31  is compressed as well when the bolt  60  is tightened down, thus providing some meaningful resistance to the user as the bolt  60  is screwed into the sonar unit  1 . The rubber washer  31  also makes it very difficult for a potential thief to access the bolt  60  between the ledge  39  of the spacer  35  and the washer  31 , so that, again, the bolt  60  has protection against a potential thief trying to cut the bolt  60 .  
         [0014]     Within the large spacer  35  is the hardened bushing  33 . This hardened bushing  33  is normally fabricated from a durable material and has several purposes. In addition to being a line of defense against the potential that a thief may cut through the spacer  35 , it permits free rotation of the spacer  35  around the bushing  33  should a potential thief try to rotate the spacer  35  of the locking device  10  in an attempt to steal the sonar device  1 . It should also be noted that the bushing  33  could be fabricated from a different material than the spacer  35  in order to make sawing through the spacer  35  and bushing  33  more difficult.  
         [0015]     The housing end  40  is generally fabricated of a durable material which is resistant to cutting and breakage. In terms of shape, the housing end  40  of the present invention has a first convex side  41  and an opposing second side (not shown) which is designed to mate with the housing  70 . The housing end  40  includes a central aperture  42 . In general, the housing end  40  is attached to the housing  70  using fasteners, such as screws or bolts  43 , but any other means of connecting the two are also possible, including the use of adhesives. The housing end  70  itself features a central aperture  71 . The central aperture  71  is designed to snugly accommodate the bolt  60  and the interlock device  50 .  
         [0016]     The housing  70  has a central aperture  71 , through which the head of the bolt  61  can be seen. While seen as an aperture when the device  10  is assembled, when disassembled, the aperture  71  forms a circular protuberance  74 , the importance of which will be discussed later in this detailed description. The housing  70  also has an offset aperture  72 , through which the lock cylinder  80  is inserted and secured. The housing  70  is also fabricated from a durable and resilient material so as to prevent the theft of the object secured.  
         [0017]     The lock cylinder  80 , said type of lock cylinder not intended to be a restriction of the present invention, and, as such, performing the purpose of identifying whether the appropriate key  90  has been inserted into the cylinder  80  and, if the appropriate key  90  has been inserted, permitting a person to turn the lock cylinder  80 . See  FIG. 1 . In actuation, turning the key  90  in the lock  80  turns the second end  82  of the lock  80 . The second end of the lock  82  is generally circular with the exception of one area  83 , which is flattened. The purpose of the flattened area  83  will be outlined later in this detailed description.  
         [0018]     The interlock  50  includes a hollow cylindrical part  59 . The hollow cylindrical part  59  has a first open end  51  and a second end  52  having an aperture  53  through which the bolt  60  is inserted. The bolt  60  is a normal bolt having a head  61 , an unthreaded portion, and a threaded portion. The open end of the interlock  51  fits over the protuberance  74  in the housing  70 . As shown, the open end of the interlock  51  is almost star-shaped wherein the points outward  55  are connected by arcuate curves  56  which curve inwardly towards the cylindrical portion  59  of the interlock  50 . These arcuate curves are designed to accommodate the curve of the outer lock cylinder  81 .  
         [0019]     The second end of the interlock  52 , as mentioned before, has an aperture  53 , through which the bolt  60  extends. The bolt  60  can be any standard bolt, but in this embodiment is a hexagonal headed bolt. The inside of the interlock  50  then has a complimentary six-sided aperture (not shown) in which the bolt head  61  rests. In this manner, the head  61  of the bolt  60  is not permitted to rotate with respect to the interlock  50 .  
         [0020]     The locking device  10  of the present invention is operated by turning a key  90  in the lock cylinder  80  in one direction, wherein the curve of the outside  81  of the lock cylinder  80  matches up with the arcuate curve  56  of the interlock  50 , which permits the user to screw in or unscrew the device  10  of the present invention. This corresponds to the “unlocked” position.  
         [0021]     The opposite is true of the other lock position. When the lock cylinder  80  has been turned to the other position, the locking device  10  of the present invention is locked. That is, the flat surface  83  of the lock cylinder  80  has been presented to the arcuate curve  56  of the interlock  50 . In this position, a potential thief can rotate the housing  70  freely and it has absolutely no effect on the relative position of the bolt  60  with respect to the sonar unit  1  it is protecting. This corresponds to the “locked” position.  
         [0022]      FIG. 3  shows yet another use for the locking device  10  of the present invention. As shown in  FIG. 3 , the locking device  10  is used to secure the clamshell mounts  104 ,  105  to the ball mount  106  of the ball mount assembly  100 . The ball mount  106  is attachable to a console or other surface  109  by means of fasteners  103 . The height and position of the sonar unit  1  is then adjustable by simply loosening the locking device  10  as previously described.  
         [0023]     The present invention also provides a method for using the locking device  10  described above. More particularly, the present method provides for the steps of using a locking device  10 , wherein the locking device  10  has a threaded end and is inserted into a threaded aperture to secure something, for example, a marine sonar device  1 , to a bracket  5 . See  FIG. 1 . The present method provides for the steps of using the locking device  10  having a threaded end  60 , and providing a large spacer assembly  30  between said locking device  10  and said bracket  5 . The method of the present invention may also include the step of using a large spacer  35  having an inner diameter aperture  36  that is larger than that of the threaded end  60 , wherein a bushing  33  could be inserted between the spacer  35  and the threaded rod  60  such that the spacer  35  is free to rotate independent of the bushing  33 . The method of the present invention would normally provide a spacer  35  that would be designed to accommodate the housing end  40  of the locking device  10 . For example, the method of the present invention provides for a spacer  35  having a concave end with a curve matching that of the housing end  40  such that it would be more difficult for a potential thief to damage the bolt  60 . The present invention may utilize a single structure for the spacer  35  and housing end  40 . The present invention may also include using two different materials for the spacer  35  and the bushing  33 .  
         [0024]     The method of the present invention may further include the step of selecting materials based on their resistance to cutting or breakage. For example, the spacer  35  material may be selected for its resistance to impact, while the bushing  33  material is resistant to cutting. Additionally the materials may be selected such that, different types of blades are required to cut through the different materials such that perhaps the spacer  35  material would be susceptible to a serrated edge while the bushing  33  was susceptible to a straight edge and ruined the cutting efficiency of the serrated edge to frustrate a potential thief.  
         [0025]     The method of the present invention may also provide for the step of using a resilient washer  31  in addition to the spacer  35  and the bushing  33 . The method of the present invention would then provide for a recessed area  38  for said resilient washer  31  and even a ledge  39  around the recessed area  38  so as to protect the resilient washer  31  from damage.  
         [0026]     In summary, the present invention also provides a method for securing an electronic instrument  1  device having a threaded aperture using a lock device  10  having a threaded rod  60  comprising the steps of: placing the bushing  20  on the threaded rod or bolt  60 ; placing a spacer  35  over the threaded rod  60  and atop of a bushing  33 ; and placing a resilient washer  31  in close relation to the spacer  35 .  
         [0027]     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details disclosed and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept.