Abstract:
A releasably securable security apparatus for securing the tailgate and rear canopy window of a pick-up vehicle equipped with a canopy, provides a releasably securable securing frame and a mounting means capable of being attached and secured to the side walls of the cargo box of the pick-up vehicle. The securing frame is mountable onto the pick-up vehicle, such that when in a closed position, the securing frame is positioned generally astride a tailgate and rear canopy window of the pick-up vehicle, and when secured in such closed position, prevents the tailgate and/or rear canopy window from being opened, and when in an open position, allows the tailgate and/or the rear canopy window to be opened so as to allow loading and unloading. The securing frame may be one-piece or two-piece. The two-piece securing frame comprises two gates, each for mounting on an opposite side of the rear of the pick-up and gates lockable to each other in the closed position.

Description:
FIELD OF THE INVENTION 
     This invention relates to a locking security apparatus for a vehicle that is equipped with a canopy or similar closeable cover or housing, in particular, such locking security apparatus for a pick-up vehicle, such as a pick-up truck, that is equipped with a canopy. 
     BACKGROUND OF THE INVENTION 
     Open-deck vehicles such as pick-up trucks are often provided with a canopy. Such a canopy is used to protect cargo carried in the cargo box of a pick-up vehicle from rain, snow, dust and falling debris. Additionally, a canopy may offer some protection against and deter thefts from the back of the pick-up vehicle. A canopy is typically made from material of relatively rigid construction, most commonly fibreglass, and is secured to or installed upon the cargo box side walls. Many canopies are provided with a rear canopy window that is made from transparent or semi-transparent material such as glass or clear plastic, so as to enable the driver to see to the rear of the pick-up vehicle. This rear canopy window may optionally be in the form of a releasably securable window or hatch. 
     Pick-up vehicles are commonly used as work vehicles and used to transport large, and often expensive, items such as tools. Consequently, such vehicles are often targeted for thefts. For those vehicles equipped with canopies, the preferred route of access by thieves is through the back of the canopy-equipped pick-up vehicle, particularly when relatively long or bulky items are to be removed, since it is generally easier to slide these items through the back. Further, as already described, most canopies are provided with a rear canopy window typically made of glass or plastic, which canopy window is hence often easier to break compared with some of the other exposed portions of the canopy (which are typically made of fibreglass or aluminum). Thieves, especially when attempting to steal very bulky items, will break the rear canopy window or, if the rear canopy window is in the form of a hatch, will break or prise open the hatch. The items in the back of the vehicle can then be slid out through the back and removed via the broken or prised-open hatch or window. In many instances, breaking or prising open the rear canopy window will further allow the thieves to open the rear tailgate of the pick-up vehicle. Once the tailgate is opened, the bulky items can often be slid out through the back of the pick-up vehicle even more easily and quickly (items can be removed without having to lift them over the closed tailgate). Alternatively, thieves may choose to gain access by prising open the tailgate alone (without first breaking or prising open the rear window). 
     Various methods have been devised to address the theft problem. Pearson teaches a truck canopy and tailgate locking means in U.S. Pat. No. 4,819,461. Pearson discloses a locking device for securing the rear canopy door and tailgate of a canopy-equipped truck to the truck&#39;s rear bumper; this locking device comprises a bar, that can be secured to the handle apparatus of a truck canopy so as to extend vertically through a hole in the rear bumper and be secured in place by use of a padlock. This locking device necessitates the truck canopy having a protruding handle mechanism, and also requires holes to be drilled in a portion of the rear bumper. Further, this locking device has the drawback of not being very effective in deterring or hindering thieves from stealing items from the back of the truck by obtaining access through the rear canopy window. If the rear window is broken, all but the most bulky of items can still be removed through the rear window with relative ease. 
     Zock in U.S. Pat. No. 5,165,743 discloses a tailgate locking device for securing the tailgate and canopy of a truck, which device locks the handle of the tailgate and the handle of the canopy together. This device also suffers from the same drawback described for Pearson in that the locking device is ineffective in hindering or preventing thefts where access is gained by breaking or prising open the rear canopy window. 
     SUMMARY OF THE INVENTION 
     In this specification and in the claims, terms such as up and down, left and right, and horizontal and vertical are used to describe the invention and its embodiments. These terms are used for convenience as they relate to the orientation of the embodiments of the invention as typically installed on a pick-up vehicle. These terms are used solely to aid in describing the invention and the invention is not limited to embodiments conforming to the described orientations. 
     It is an object of the present invention to provide a security apparatus for releasably securing a rear canopy window (or rear canopy door) and tailgate of a canopy-equipped pick-up vehicle, so as to prevent, or at the very least hinder, thefts from the cargo box of such pick-up vehicle. It is a further object of the invention to provide a security apparatus for securing the rear window and tailgate of a canopy-equipped pick-up vehicle, which apparatus can be easily repeatedly locked and unlocked as desired to allow loading into, and unloading from, the cargo box. It is an object of an aspect of this invention to provide an apparatus for securing the rear window and tailgate of a pick-up vehicle equipped with a canopy, which apparatus can be easily installed onto existing canopy-equipped pick-up vehicles and easily uninstalled as required. Other objects and advantages of the present invention will become more apparent in light of the following description. 
     The invention in one embodiment is a releasably-lockable security apparatus comprising two mounts, for installing on a canopy-equipped pick-up vehicle, and a securing frame mountable on the mounts. When the mounts are installed on the pick-up vehicle the securing frame can be mounted on the mounts and locked in a closed position wherein the securing frame spans and closely overlies the tailgate and window so as to prevent the tailgate and window from swinging open. The securing frame is preferably a pair of gates whose distal ends can be locked together, each gate in one embodiment pivoting about a substantially vertical axis located at the outside of the cargo box in the vicinity of the back of the pick-up vehicle, with the mounts each preferably providing pivotal support for an associated gate. The securing frame is preferably sized and shaped such that when the securing frame is in the closed position, it impedes removal of objects from the cargo box through the window opening even if the window is forced open or broken. The securing frame can be moved, either by swinging the securing frame or removing the securing frame from the mounts, to an open position wherein the securing frame does not impede the opening of the window and tailgate, and thus allows items to be loaded into, and unloaded from, the cargo box. 
     Preferably the mounts can be installed on the sides of the pick-up vehicle such that when the securing frame is in the closed position the securing frame extends substantially horizontally across the rear of the pick-up vehicle. Alternatively, one mount can be installed below the tailgate, and the other mount can be installed above the window such that when the securing frame is in the closed position the securing frame extends between above the window and below the tailgate. In a preferred embodiment, the mounts are suitable for attaching to the sides of the pick-up vehicle such that the securing frame extends horizontally across the rear of the pick-up vehicle when in the closed position. The securing frame is preferably two-part, but the securing frame may in some embodiments be one-part. With a two-part securing frame, the securing frame comprises: two gates, each gate pivotally attached to a respective mount such that each gate can be independently swung through a substantially horizontal arc; and a means for releasably locking the gates, one to the other, in the closed position. With a one-part securing frame, the securing frame may be releasably lockable in that each end of the securing frame is releasably lockable to a respective mount, or the securing frame may be swingable in that one end of the securing frame is releasably lockable to one mount and the other end of the securing frame is pivotally attached to the other mount such that the securing frame can be swung through a substantially horizontal arc between the closed position and the open position, and releasably locked in the closed position. 
     The securing frame preferably has an open-frame configuration, perhaps grid-like or truss-like, so as to provide a relatively high area coverage and strength with relatively low weight. The securing frame may be shaped or positioned such that a portion of it aligns with and covers the tailgate latch/handle and/or lock and optionally, also the window latch/handle, thus hindering or preventing access to same when the securing frame is in the closed position. Other shapes of the securing frame are possible, and the shape of the securing frame should not be limited to that described herein. It is preferable that the overall shape of the securing frame be such that, when in the closed position, the securing frame will effectively prevent the tailgate and rear canopy window from being opened. The securing frame also preferably overlaps a significant portion of the rear canopy window so that, even if the rear canopy window is broken or prised open, the securing frame can serve to hinder access to the cargo box of the pick-up vehicle and also hinder the removal of cargo, especially large items, through the back of the pick-up vehicle. 
     In a preferred embodiment each mount is attached to the pick-up vehicle at the joint between the top of the respective side wall and the canopy. Each mount includes a mounting plate for interposing between the top of the respective side wall and the canopy. Each mounting plate may include a downward-projecting tang that abuts the inside top edge of the respective side wall when in use and through which conventional fasteners, such as screws and bolts may be inserted to fasten the mount to the pick-up vehicle. As well, the position of the mounting plates between the side walls and canopy further secures the mounting plates. It is typical for canopy-equipped vehicles to have one or more canopy clamps on each side of the canopy for securing the canopy to the side walls. Typically, the canopy clamps latch onto the side walls of the cargo box. The canopy may be further secured with conventional fasteners such as screws or bolts. For the present invention, it is preferable to provide mounting plates that can be sandwiched between the canopy clamps and the top of the side walls of the cargo box of the pick-up vehicle so that the mounting brackets can be conveniently secured without requiring additional drilling of screw holes or threaded bore holes into the side walls. Alternatively, the mounts can be located at some position on the side wall other than where the canopy clamps are located, although this will necessitate the additional drilling of holes so that the mounting brackets can be secured to the side wall. 
     In another embodiment, where it is preferable to be able to both swing and remove the securing frame, each of the gates (or the securing frame, in the case of a one-part securing frame) is releasably pivotally attached to a respective associated mount. The gates can be removed from their associated mounts when in a position other than locked in the closed position. In one embodiment, each gate comprises a downward-opening socket and each mount comprises an upwardly-projecting plug sized and shaped for insertion and partial rotation within the socket. The socket and plug include means for preventing withdrawal of the plug from the socket in a certain pivotal position of the gate while permitting withdrawal of the plug in another pivotal position or positions. In one embodiment providing a bayonet-type interconnection of plug and mating socket, the plug includes an L-shaped slot having a vertically-extending portion and a horizontally-extending portion; and the socket includes a pin sized so that the L-shaped slot can contain the pin. The pin and L-shaped slot act to retain the socket on the plug when the pin is within the horizontally-extending portion of the L-shaped slot and not within the vertically-extending portion of the L-shaped slot and to permit withdrawal of the plug when the pin is within the vertically-extending portion of the L-shaped socket. As well, the L-shaped slot can be shaped to prevent the securing frame or gates from swinging outward past a preferred position, for example, past roughly parallel with the side walls so as to prevent the securing frame or gates from swinging into traffic, and to prevent the securing frame or gates from swinging inward against the tailgate and window so as to prevent damage to the tailgate and window caused by the impact of a swinging securing frame or gate. 
     The means for releasably locking the gates together in the closed position preferably includes locking components at the distal end of each gate such that the means for releasably locking the gates is positioned generally between the two gates. It is desirable not to have the locking means too exposed, since thieves may attempt to break the locking means by the application of suitable force—e.g. by using a heavy-duty hammer or bolt cutters. Thus, in accordance with a preferred embodiment of this invention, the locking means is at least partially housed behind a cover plate, or within a sturdy lock housing, so that it is not fully exposed. 
     A one-part securing frame may preferably be releasably locked to the pick-up vehicle by means of a mount including a lock. In a preferred embodiment, the mount has an upwardly-projecting lock plug sized for insertion into a downwardly-facing lock bore within the securing frame. The lock plug contains a key lock projecting into a lock cavity and having a lock hook. The lock bore contains an eye engageable with the lock hook when the lock plug is inserted into the lock bore so as to releasably lock the securing frame. 
     Preferably, the security apparatus is additionally provided with means (e.g., telescoping means) for adjusting the span of the security frame, so that the security apparatus can be adapted for pick-up vehicles of differing sizes. 
     It is common for users to additionally equip their canopy-equipped vehicles with a roof rack. Often, a roof rack is affixed to a number of (typically four) vertical struts, and mounted onto and secured to two side rails running along each side of the vehicle, which side rails are clamped between the cargo box and the canopy, and secured in place by nuts and bolts or screws. Such side rails afford an alternative way of attaching the mounts to the pick-up vehicle. The mounts may optionally be attached, typically with conventional fasteners such as screws, or nuts and bolts to the side rails, instead of to the top of the side walls of the cargo box as previously described. 
    
    
     SUMMARY OF THE DRAWINGS 
     FIG. 1 is a schematic isometric view of a pick-up vehicle equipped with a canopy and a security apparatus in accordance with an embodiment of the present invention. 
     FIG. 2 is a rear elevation view of the pick-up vehicle and security apparatus of FIG.  1 . 
     FIG. 3 is a schematic isometric view of the right, rear corner of the pick-up vehicle showing a mount positioned on the side wall of the pick-up vehicle in accordance with an embodiment of the present invention, shown without the canopy for clarity. 
     FIG. 4 is a schematic isometric view of a pick-up vehicle, showing an embodiment of the present invention with the left and right gates swung open and the tailgate opened 
     FIG. 5 is an exploded elevation view of a security apparatus in accordance with an embodiment of the present invention. 
     FIG. 6 is a top plan view of one embodiment of the mount of the present invention, shown without the canopy for clarity. 
     FIG. 7 is a sectional view of the mount of FIG.  6 . 
     FIG. 8 is a schematic isometric view of a pick-up vehicle showing a mount of an embodiment of the present invention for use with a roof rack. 
     FIG. 9 is an isometric view of an embodiment of a gate locking mechanism of the present invention. 
     FIG. 10 is an isometric view of another embodiment of a gate locking mechanism of the present invention. 
     FIG. 11 is a sectional view of the gate locking mechanism of FIG. 10 shown in the locked position. 
     FIG. 12 is a rear elevation view of an embodiment of the present invention having a one-part securing frame. 
     FIG. 13 is side elevation view of the mount lock shown in FIG.  12 . 
     FIG. 14 is a rear elevation view of the mount lock shown in FIG.  12 . 
     FIG. 15 is a sectional view of a portion of the embodiment of the invention shown in FIG. 5 taken along the line  15 — 15  in FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, an embodiment of the security apparatus  10  is shown mounted across the back of a pick-up vehicle  12 . The pick-up vehicle  12  has a cargo box  14  with a right side wall  16 , a left side wall  18  and a tailgate  20 . A canopy  22  is mounted on the cargo box  14 . The canopy  22  has a window  24 , shown in the closed position, that can pivot at its top edge to swing upwards to an open position (not shown). 
     As shown in the drawings, the security apparatus  10  includes a securing frame  26 , a right mount  28  and a left mount  30 . The securing frame  36  is shown in FIG. 1 in the closed position, that is, the securing frame  36  is situated astride the back of the pick-up vehicle  12 , about and in close proximity to the tailgate  20  and window  24 , thereby preventing the tailgate  20  and window  24  from opening outwards, and also impeding the removal of items through the rear of the canopy  22  should the window  24  be broken. 
     The embodiment of the securing frame shown in FIGS. 1,  2 ,  4  and  5 , is two-part, comprising a right gate  32  and a left gate  34 . As shown in FIGS. 1,  2 ,  4  and  5 , the right gate  32  and associated right mount  28 , are substantially a mirror image of the left gate  34  and associated left mount  30 . Therefore, except where the gates and associated mounts differ from each other, only one gate and mount will be described and it is understood that the description of the gate and mount applies equally to the right gate  32  and right mount  28 , and the left gate  34  and left mount  30 . 
     In the embodiment shown in FIG. 5, each gate is two-piece, comprising a barrier  40  and an arm  42 . In the embodiment shown in FIG. 5, the barrier  40  is paddle-shaped, but the barrier  40  can be any shape that, when the securing frame  26  is closed, prevents the tailgate  20  and window  24  from opening and acts to, at least in part, block the removal of items through the window  24  in the event the window  24  is broken. The arm  42  has a roughly ninety degree bend in a substantially horizontal plane, so as to enable the arm  42  to reach the back of the pick-up vehicle when mounted on the side of the pick-up vehicle  12 . In the embodiment shown in FIGS. 1,  2 ,  4  and  5 , the arm  42  also has a roughly ninety degree bend in a substantially vertical plane, so as to enable the arm  42  to be mounted on the embodiment of the mount shown in those drawings. 
     The arm  42  has an adjustment bore  44  having an internally-projecting adjustment lug  46 . The barrier  40  has an adjustment insert  48  sized for loose-fit insertion into the adjustment bore  44  and a longitudinally-extending adjustment slot  50 , sized to contain the adjustment lug  46  so as to prevent the barrier  40  and arm  42  from rotating relative to each other, but so as to permit the adjustment insert  48  to slide longitudinally within the adjustment bore  44 , when the adjustment insert  48  is inserted into the adjustment bore  44 . In this way, the length of the gates can be adjusted to accommodate cargo boxes  14  of different widths. Other means for adjustably connecting the arm  42  and barrier  40  are possible, and would be apparent to one skilled in the art, such as for example, the use of a threaded rod in combination with a receiving threaded socket (not shown), said threaded rod affixed to the arm  42  and the receiving threaded socket affixed to the barrier  40 , or vice versa. As well, in some situations it is not necessary to be able to adjust the length of one or both gates, in which case one gate or both gates can be one-piece. 
     One mount embodiment, shown in FIGS. 3 and 5, includes a mounting plate  60  and a vertical plug  62 . The mounting plate  60  is shaped so as to span the top of the right or left side wall  24 ,  26 , with, as shown in FIG. 5, a downward-projecting tang  64 , which abuts the top inside edge of the sidewall  24 ,  26  when the mounting plate  60  is in use and through which conventional fasteners, such as screws or bolts (not shown) can be inserted to fasten the mounting plate  60  to the sidewall. The mounting plate  60  includes a sloped platform  66  to which the plug  62  is attached and from which the plug  62  projects vertically upwards. In FIG. 3, the canopy  22  is not shown so as to better show the position of the right mount  28  on the right sidewall  16 . In normal use, as shown in FIGS. 1,  2  and  4 , the mounting plate  36  is interposed between the top of the respective right or left sidewall  16 , 18 , and the canopy  22 . As shown in FIG. 5, the plug  62  has an L-shaped slot  68  and the arm  42  has a downward-facing socket  70  with an internally-projecting pin  72 . The plug  62  is sized for loose-fit insertion into the socket  70 , and the pin  72  and L-shaped slot  68  are sized so that the L-shaped slot  68  can contain the pin  72 , such that the plug  62  can be inserted into, and removed from, the socket  70  when the pin  72  is within the vertically-extending portion of the L-shaped slot  68 , and the plug  62  can be rotated within the socket  70 , when the pin  72  is within the horizontally-extending portion of the L-shaped socket  70 . The pin  72  and L-shaped slot  68  act to retain the socket  70  on the plug  62  when the pin  72  is within the horizontally-extending portion of the L-shaped slot  68  and not aligned within the vertically-extending portion of the L-shaped slot  68 . In use the pin  72  and L-shaped slot  68  are oriented to act to retain the plug  62  within the socket  70  when the respective gate is in position across the back of the pick-up vehicle  12  so as to prevent the tailgate  20  and window  24  from opening outwards, and to permit the arm  42  to be lifted from the plug  42  when the arm  42  is swung outward to some other position. As well, the L-shaped slot  68  can be shaped to prevent the gates  32 ,  34  from swinging outward past a certain position, for example, past roughly parallel with the side walls  16 ,  18  so as to prevent the left gate  34  swinging into traffic when the pick-up vehicle is parked at the side of the road, and to prevent the gates  32 ,  34  from swinging inward against the tailgate  20  and window  24  so as to prevent damage to the tailgate  20  and window  24  caused by the impact of a swinging gate  32 ,  34 . FIG. 4 shows this embodiment of the security apparatus  10  with the left and right gates  32 ,  34 , swung open and the tailgate  20  lowered for access to the cargo box  14 . 
     In another mount embodiment for use where it is not desirable to be able to remove the gates or one-piece securing frame, as the case may be, shown, without the canopy  22 , in top plan view in FIG.  6  and in sectional view in FIG. 7, the arm  42  is attached to a pivot cylinder  80 . The pivot cylinder  80  has a top washer  82  and a bottom washer  84 . The pivot cylinder  80  projects through, and fits loosely within, the top hole  86  in the top strap  88  and the bottom hole  90  in the bottom strap  92 , so as to permit the pivot cylinder  80  to rotate relative to the top and bottom straps  88 ,  92 . The top washer  82  is larger than the top hole  86  and acts to prevent the pivot cylinder  80  from moving downward through the top strap  88 . The bottom washer  84  is larger than the bottom hole  90  and acts to prevent the pivot cylinder  80  from moving upward through the bottom strap  92 . The bottom strap  92  is attached to the top strap  88  at the gusset  94 . The top strap  88  extends across the top of the of the side wall (the left side wall  18  in FIGS. 6 and 7) and has a downward-projecting member  96  having fastener holes (not shown) through which conventional fasteners such as screws  98  or bolts can be inserted to attach the top strap  88  to the side rail. This mount embodiment does not require that the arm  42  have a bend in a substantially vertical plane, but does require that the arm  42  have a bend in a substantially horizontal plane . The arm  42  projects horizontally from the pivot cylinder  80  and the rotational freedom of the pivot cylinder  80  within the top and bottom strap  88 ,  92  permits the arm  42  to swing in a horizontal arc. 
     FIG. 8 shows another mount embodiment for use with a pick-up vehicle  12  equipped with a roof rack  100  having longitudinally-extending side rails  102  interposed between the top of the side walls  16 ,  18  and the canopy  22 . As shown in FIG. 8, typically with such roof racks  100 , a portion of each side rail  102  projects from the sides of the vehicle, usually along the whole length of the sidewalls  16 ,  18  as shown in FIG. 8. A mount  28 ,  30  can be attached to the side rails  102 , typically with nuts and bolts, or by welding. FIG. 8 shows a mount  28  of the type having a plug  62 , attached to the rearward end of the side rail  102 , but it will be clear that other mount embodiments such as that shown in FIGS. 6 and 7 can be adapted for attaching to the side rails  102 . The mount embodiment shown in FIGS. 6 and 7 can be adapted for attaching to the side rails  102  by removing the downwardly projecting member  96  so that the top strap  88  can be attached to the bottom or top of the side rails  102  with any conventional fastener such as nuts and bolts, or by welding. 
     As shown in FIGS. 1,  2 ,  4 , and  5 , the two-part securing frames include a lock mechanism  110  for locking the right gate  32  to the left gate  34  in the closed. A preferred embodiment of the lock mechanism  110 , shown in FIG. 9, includes a cover plate  112  (shown in outline) attached to one of the barriers  40 . A pair of lock fingers  114  project from each barrier  40 . The lock fingers  114  have lock pin holes  116  that align when the left and right gate  32 ,  34  are in the closed position, so as to permit the lock pin  118  to be inserted through the lock pin holes  116  and secured with a padlock  120 . The cover plate  112  prevents tampering with the lock pin  118  and padlock  120 . 
     Another embodiment of the lock mechanism, shown in FIGS. 10 and 11, includes a backing plate  122  attached to one of the barriers  40  and a lock box  124  attached to the other barrier  40 . The backing plate  122  has a projecting lock loop  126  attached to it. The lock box  124  has a loop opening  128 , through which the lock loop  126  projects when the left and right gate  32 ,  34  are in position to prevent the tailgate  20  and window  24  from opening outwards. The lock box  124  has a bottom opening  130  through which a padlock  120  can be inserted to lock around the lock loop  126  so as to secure the lock loop  126  in the lock box  124  and thereby to lock the right gate  32  to the left gate  34 . The lock box  124  protects the padlock  120  from blows, such as from a hammer, that might break the padlock  120 , and makes it difficult to cut the padlock  120 , such as with bolt cutters. 
     In another embodiment of the security apparatus  10 , shown in FIGS. 12,  13  and  14 , the securing frame  26  is one-part. As shown in FIG. 12, the right mount  28  is a pivoting mount having a plug  62  as described above and the left mount  28  has a mount lock  132 . It will be clear that other pivoting mounts, such as the mount shown in FIGS.  6  and  7  can be used instead of the right mount  28  shown in FIG.  12 . It will be clear that the mount lock  132  and pivoting mount could be on either side of the cargo box  14 . However, it is preferable to locate the pivoting mount on the side of the pick-up vehicle  12  away from the traffic when the pick-up vehicle  12  is parked at the side of the road so as to prevent the securing frame from swinging into traffic. As shown in FIGS. 13 and 14, the mount lock plug  134  is sized for insertion into a downwardly-facing lock bore  136  within the securing frame  26 . The lock plug  134  contains a key lock projecting into a lock cavity  140  and having a lock hook  142 . The lock bore  136  contains an eye  144 . When the lock plug  134  is inserted into the lock bore  136 , the key lock  138  can be turned with a key (not shown) to hook the eye  144  with the lock hook  142  so as to lock the securing frame  26  to the mount lock  132 . 
     Another possible, but non-preferred, embodiment (not shown) of the security apparatus  10  having a two-part securing frame  26 , involves positioning the mounts  28 ,  30  at the back, outside corners of the side walls  16 ,  18 , so that the gates  32 ,  34  can be straight, in that each gate need not bend around the adjoining corner of the canopy  22  and cargo box  14 . Positioning the mount pivot axis so that it is diagonally offset a sufficient distance from the corner of the cargo box  14  permits swinging the gate forward and parallel to the respective side wall  16 , 18 . Thus, the gates  32 ,  34  can be attached at the side walls  16 , 18  as an alternative to removing them in situations where it is preferable to not have to lock and unlock the gates each time the pick-up vehicle  12  is moved. 
     Another possible, but non-preferred, embodiment (not shown) of the security apparatus  10 , involves configuring the L-shaped slot  68  so that it is not all the way through the material of the plug  62  but is merely a groove in the surface of the plug  62  extending horizontally further around the plug  62  than the shown L-shaped slot  68 . The pin  72  can be sized so as to fit within the groove. In this way, the gates  32 ,  34  can be pivoted through a larger arc than possible with the L-shaped slot  68  shown in the drawings. 
     Another possible, but non-preferred, embodiment (not shown) of the security apparatus  10 , involves making a pivoting means part of the securing frame  26  such that a short rectangularly-shaped tongue (such as square tubing)is pivotably attached to the main part of the securing frame, with a bend in the tongue as required so as to permit the tongue to be swung from a position beside, and roughly parallel to, the securing frame  26  through 270° to a position where the tongue is roughly 90° to the securing frame  26 . The mount for such a securing frame  26 /tongue arrangement comprises a mounting bracket having a rectangular bore (as within square tubing), sized so that the tongue can be inserted into it. In use, the mounting brackets re mounted at the back end of the side walls  16 ,  18 , with the rectangular bore extending horizontally roughly parallel to the back of the cargo box  14 . The mounting brackets might include a flat plate so that they can be mounted to the cargo box  14  by interposing the plate between the top of the sidewalls  16 ,  18  and the bottom of the canopy  22 . In use, each tongue is inserted into the rectangular bore from the side of the cargo box  14  in a direction generally towards the center of the cargo box  14 . When the tongue is inserted into the rectangular bore, the gates  32 ,  34  can be swung parallel to the tongue and locked into place. When the gates  32 ,  34  are locked to each other (or the securing frame  26  is locked to the other side of the cargo box in the case of the one-part securing frame  26 ), the gates  32 ,  34  are secure because the tongue cannot be removed from the rectangular bore, in that, in order to remove the tongue, the gates must be shifted sideways in the direction of the mounting bracket, which is prevented by the lock at the other end of the gate. 
     As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.