Patent Abstract:
A trailer locking system includes separate sections releasably coupled to provide locking frames that secure trailers against unauthorized entry through side doors and rear doors. The sections include frame members adapted for releasable coupling to other frame members to form the locking frames, along with support structure for selectively locating the locking frames relative to the trailer body. The locking frames can surround their associated trailers, or may span the width of the doors they are intended to secure. Locking frames that surround the trailers can be supported by ground engaging legs independently of the trailer, or by support members along the trailer top and sides that additionally provide a carrier for equipment and supplies. Adjacent frame members are releasably joined by coupling plates and stabilizing pins mounted to selected coupling plates. Other coupling plates have pin-receiving apertures, and all coupling plates have locking apertures to accommodate padlocks or other locking devices.

Full Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to apparatus and systems for restricting access to containers and vehicles, and more particularly, to devices for preventing unauthorized entry into unattended trailers.  
         [0002]     Trailers serve a wide variety of personal and business needs, ranging from camping and other recreational activities, moving furniture, appliances and other personal property, to carrying tools and equipment to and from construction sites and storage at the sites. A trailer typically has a pair of hinge supported doors at its rearward end, extending substantially the full height from the deck of the trailer to its roof. The doors are securely closed by a vertically extending rod, with a lever or handle attached to the rod and pivotable into a door closing position. A latch and lock, e.g. a padlock, can be used to secure the handle in the door closing position. Some trailers include additional, single hinge supported doors along one of their side walls, with a similar vertical rod, handle and latch arrangement to secure the door.  
         [0003]     For many uses, this locking arrangement is sufficient. However, whenever a trailer is left unattended for an appreciable amount of time, for example at a construction site or other remote location, it becomes susceptible to attempts to gain unauthorized entry, increasing the risk of theft or vandalism to the contents of the trailer.  
         [0004]     In recognition of the need for better security, systems have been developed to augment the protection provided by the rod/handle arrangements. For example, U.S. Pat. No. 5,934,116 (Moore) shows a system with two block sections, one secured to each door of a trailer, and a rectangular bar contained in the block sections and spanning the distance between them. U.S. Pat. No. 6,834,896 (Smith) shows tubular locking assemblies designed to prevent rotation of the vertical rods away from the positions that secure the doors.  
         [0005]     Locking devices designed to prevent entry into vehicles are shown in U.S. Pat. No. 6,349,573 (Johnson) and U.S. Pat. No. 5,035,458 (Boensch). With regard to stationary containers, U.S. Pat. No. 4,418,551 (Kochackis) and U.S. Pat. No. 5,108,166 (Klix) show cages designed to enhance vending machine security by completely surrounding the vending machines.  
         [0006]     Although the foregoing systems may be suitable for a variety of uses, they fail to address certain objects achieved by trailer locking systems configured according to the present invention.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention has several aspects, each directed to one or more of the following objects:  
         [0008]     The first of these objects is to provide a trailer locking system that does not require any modification of the trailer, and does not require a permanent mounting of locking system hardware to the trailer.  
         [0009]     Another object is to provide a trailer locking system that a single individual can easily configure into a secure and positive locking engagement with the trailer.  
         [0010]     A further object is to provide a universal locking system readily useable with a variety of trailers in a given size range.  
         [0011]     Yet another object is to provide a trailer locking system having additional utility as a carrier.  
         [0012]     One aspect of the invention is a locking system for securing a trailer having a substantially horizontal deck, a perimeter wall extending upwardly from the deck, a roof cooperating with the deck and perimeter wall to enclose an interior of the trailer, an entrance along the perimeter wall, a door mounted to the perimeter wall for closing the entrance, and wheels or other means of supporting the deck above ground.  
         [0013]     The locking system includes a plurality of substantially rigid frame members. A coupling structure is provided for releasably securing the frame members to one another to form a trailer locking frame. A support structure, mounted to the trailer locking frame, is adapted to support the locking frame in a locking position in substantially surrounding relation to a perimeter wall of a trailer in close proximity to the perimeter wall, and with a portion of the locking frame extending across an entrance of the trailer to prevent the opening of a door at the entrance to gain entry into the trailer so long as the frame members are so secured. A retaining component is mounted with respect to the trailer locking frame and extends beneath a deck of the trailer when the locking frame is in the locking position, thereby being disposed to engage the deck in response to movement of the locking frame upwardly from the locking position to prevent further upward travel of the locking frame relative to the trailer.  
         [0014]     Several advantages arise from the fact that the locking frame in the locking position substantially surrounds, but does not necessarily contact, the perimeter wall. There is no need for a tight fit or exact alignment of the locking frame with the perimeter wall or any particular segment of the perimeter wall, such as the segment where a trailer door is located. Consequently there is no need modify or adapt the trailer to accommodate the locking frame, and no need to mount locking system hardware to the trailer. In addition, the locking frame is usable with virtually any trailer within a given size range.  
         [0015]     The preferred support structure is a plurality of elongate support legs extending downwardly from the locking frame, more particularly from selected frame members. The preferred retaining component comprises substantially horizontal extensions fixed to bottom portions of the support legs. This allows a frame member and its associated legs and extensions to be configured as a self-standing structure. For an individual working alone, this considerably eases the task of assembling the frame members into the locking frame.  
         [0016]     Another aspect of the invention is a trailer locking apparatus. The apparatus includes a plurality of substantially rigid frame members adapted for assembly into a trailer locking arrangement. A plurality of coupling plates are mounted integrally to free end portions of the frame members and adapted to form pairs of adjacent confronting coupling plates when the frame members are assembled into the locking arrangement. The coupling plates have respective locking apertures, and the locking apertures of each confronting coupling plate pair are alignable to receive a locking device for forming a releasable locking engagement of the coupling plate pair. A first coupling plate of each coupling plate pair supports a locking pin that extends longitudinally away from the first coupling plate and is spaced apart transversely from its associated locking aperture. A second coupling plate of the coupling plate pair includes a pin-receiving aperture spaced apart transversely from its associated locking aperture to receive the locking pin and thereby prevent any substantial rotation of the coupling plates relative to one another about longitudinal axes when the coupling plates are in said releasable locking engagement.  
         [0017]     Thus, confronting pairs of the coupling plates cooperate to enhance security of the trailer locking apparatus through greater resistance to rotation of adjacent frame members relative to one another. This improves security, not only in free standing locking systems, but also for systems in which at least one of the frame members is permanently fixed to the trailer.  
         [0018]     Preferably the frame members along their free end portions have longitudinal axes, and the coupling plates are mounted with their major planes perpendicular to the longitudinal axes. This positions the coupling plates for more effective resistance to frame member rotation.  
         [0019]     Yet another aspect of the present invention is a trailer lock and carrier system for use with a trailer having a deck, a perimeter wall extending upwardly from the deck, a roof cooperating with the deck and perimeter wall to enclose an interior of the trailer, an entrance along the perimeter wall, and a door mounted to the perimeter wall for closing the entrance.  
         [0020]     The lock and carrier system includes a plurality of substantially rigid frame members. A coupling structure is provided for releasably securing the frame members to one another to form a trailer locking frame. The system further includes a locking frame support assembly including an upright support member fixed at a lower end region thereof to a selected one of the frame members, and a top support member fixed to an upper end region of the upright support member. A mounting component is adapted to mount the locking frame support assembly integrally to a trailer with the top support member extending over a roof of the trailer and with the upright support member extending downwardly from the top support member along a perimeter wall of the trailer to locate the selected frame member in close proximity to the perimeter wall, thereby to support the locking frame in a locking position with a portion of the locking frame extending across an entrance of the trailer to prevent the opening of a door at the entrance to gain entry into the trailer, so long as the frame members are so secured.  
         [0021]     Preferably the portion of the locking frame extending across the trailer entrance is composed of a frame member other than one of the selected frame members. Then, a user can gain access to the trailer by disconnecting a single frame member from the trailer locking frame, in lieu of disassembling the frame. Accordingly it is more convenient to lock and unlock the system. The locking frame is carried by the trailer and disposed completely above the ground. As a result, the trailer can be used to transport cargo without removing or altering the system. In a particularly preferred embodiment, the locking frame support assembly comprises a forward subassembly and a rearward subassembly, each with a top support member extending substantially horizontally over the roof, and first and second upright support members extending downwardly along the perimeter wall from opposite end regions of the top support member. In this arrangement, the top support members cooperate to provide a roof top carrier for equipment and supplies, for example ladders, pipe sections and lumber.  
         [0022]     Thus in accordance with the present invention, trailer locking systems provide enhanced security against unauthorized entry, are more convenient to use, and can be adapted to different styles of trailers within a given size range without the need to mount hardware to or otherwise modify the trailer itself. In addition, as exemplified in alternative embodiments, locking systems with components permanently attached to trailers can provide rooftop carriers. 
     
    
     IN THE DRAWINGS  
       [0023]     Further features and advantages will become apparent upon consideration of the following detailed description and drawings, in which:  
         [0024]      FIG. 1  is a perspective view of a trailer and a trailer locking system configured according to the present invention;  
         [0025]      FIG. 2  is a side elevation of the trailer and locking system;  
         [0026]      FIGS. 3-5  are perspective views showing individual sections of the locking system;  
         [0027]      FIG. 6  is a partially sectioned side view illustrating a coupling of the locking system components;  
         [0028]      FIG. 7  is a perspective view showing a trailer and an alternative embodiment trailer locking system;  
         [0029]      FIG. 8  is a sectional elevation illustrating the mounting of a locking system component to the trailer;  
         [0030]      FIG. 9  is a perspective view showing the rear portion of a trailer equipped with another alternative embodiment trailer locking system;  
         [0031]      FIG. 10  is a perspective view showing part of the side wall of a trailer equipped with a further alternative embodiment locking system;  
         [0032]      FIG. 11  is a perspective view showing an alternative embodiment coupling plate for joining locking system components; and  
         [0033]      FIG. 12  is an elevational view showing a hinged coupling of locking system components. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]     Turning now to the drawings, there is shown in  FIGS. 1 and 2  a trailer locking system  16  surrounding and locking a trailer  18 . The trailer has a rectangular trailer body supported above ground by wheels  20  and a hitch  22 , which in use is coupled to a ball or other connector at the rear of a towing vehicle. When not in transit, hitch  22  can be supported above ground by a block  24  as shown in  FIG. 2 . The trailer body includes a floor or deck  26  that is horizontal when the trailer is supported as shown, a horizontal roof  28 , and a perimeter wall arrangement extending vertically between the deck and roof. The perimeter wall arrangement includes a front wall  30 , a back wall  32 , and opposite side walls  34  and  36 . A portion of side wall  34  is shown cut away in  FIG. 2 , to reveal front wall  30  and side wall  36 .  
         [0035]     Entrances to the trailer interior are formed through side wall  34  and back wall  32 . The back entrance is closed by opposed rear doors  38  and  40 , each supported pivotally by hinges  42 . A portion of door  38  is shown cut away to reveal deck  26 . The rear doors are kept tightly closed by a cam action rod  44 , a handle  46  secured to rod  44  to pivot about an axis perpendicular to the rod length, and a latch  48  designed to capture the handle and maintain the rod in the closed position.  
         [0036]     The side entrance is closable as shown by a side door  50  supported pivotably by hinges  52 , and kept closed by a cam action rod  54 , handle  56  and latch  58 . While padlocks or other locking devices can be secured to latches  48  and  58  to lock the trailer, locking system  16  provides the enhanced security called for when the trailer is left unattended for extended time periods. Trailer locking system  16  is conveniently considered to include two primary functional components: a locking frame that surrounds the trailer, and a support structure for supporting the locking frame at a desired height. The locking system is composed of four sections, three of which incorporate both locking frame and support structure functions.  
         [0037]     A front section  60  ( FIG. 3 ) includes a C-shaped locking frame member  62  with a medial region  64  and opposed, parallel end regions  66  and  68 . Frame member  62  is supported by a pair of vertical legs  70  and  72  with respective horizontal leg extensions  74  and  76 . As seen in  FIG. 2 , the leg extensions are directed inwardly beneath the trailer body when locking system  16  is secured around the trailer. Thus, the leg extensions are positioned to encounter deck  26  in response to vertical travel of the locking frame relative to the trailer, to prevent further vertical travel. Due to leg extensions  74  and  76 , the locking frame cannot be lifted sufficiently to remove it from the trailer.  
         [0038]     Another useful feature of leg extensions  74  and  76  is that they are capable of supporting section  60  upright as shown in  FIG. 2  when the front section is separated from the rest of locking system  16 . This “stand alone” feature provides for a more convenient assembly of the system components into the locking arrangement around trailer  18 , especially for an individual working alone.  
         [0039]     At the free ends of end regions  66  and  68  are coupling components, including respective coupling plates  78  and  80 , and respective stabilizing pins  82  and  84 . The pins are fixed to their associated plates and extend longitudinally, i.e. in the length direction of the end regions, while the coupling plates are oriented transversely to more effectively resist rotation about longitudinal axes. A locking aperture  85  is formed through each coupling plate.  
         [0040]     As seen in  FIG. 4 , a back section  86  consists essentially of a C-shaped frame member  88  with a medial region  90  and opposed, parallel end regions  92  and  94 . Section  86  does not include any support structure. Coupling components at the free ends of regions  92  and  94  include a coupling plate  96  and stabilizing pin  98  associated with end region  92 , and a coupling plate  100  and stabilizing pin  102  associated with end region  94 . The coupling plates and pins are oriented relative to their associated end sections as previously described. Locking apertures  101  are formed through coupling plates  96  and  100 .  
         [0041]      FIG. 5  shows a side section  104  including an elongate frame member  106 , coupling plates  108  and  110  at the opposite ends of frame member  106 , and a vertical leg  112  depending downwardly from the frame member. Leg  112  does not have a horizontal leg extension, although such extension can be formed optionally, as indicated in broken lines at  114 . No stabilizing pins extend away from frame member  106 . Rather, each coupling plate is provided with a pin receiving aperture as indicated at  116  for coupling plate  108 . Locking apertures  118  are formed through coupling plates  108  and  110 .  
         [0042]     The system components further include another side section  120  substantially identical to side section  104 , with a frame member  122  and a vertical leg  123  to support the frame member.  
         [0043]     In all of the sections, the frame members, legs and leg extensions preferably are formed of tubular steel, with elongate linear tubing sections welded together to form the L-shaped and C-shaped members. The coupling plates likewise are formed of steel, and are welded to their associated frame members. Other suitable materials include stainless steel, steel alloys, aluminum, fiberglass, and high tempered plastics.  
         [0044]     Returning to  FIGS. 1 and 2 , locking system sections  60 ,  86 ,  104  and  120  are releasably joined by locking devices such as padlocks  124  to secure the trailer. Frame members  62 ,  88 ,  106  and  122  cooperate to form a rectangular locking frame that surrounds the trailer, supported at the desired height by legs  70 ,  72 ,  112  and  123 . Frame member  88  prevents entry into the trailer through rear doors  38  and  40 , while frame member  106  denies entry through side door  50 .  
         [0045]      FIG. 6  illustrates the coupling of frame member  88  with frame member  106 . The other system couplings are substantially identical. Just prior to coupling, end region  94  and frame member  106  are positioned to confront one another with their longitudinal axes substantially coincident, as shown. Then, as the frame members are moved longitudinally toward each other, pin  102  enters pin receiving aperture  116  to maintain the alignment during continued movement, until coupling plates  100  and  108  engage. At this point it may be necessary to rotate one of frame members  88  and  106  about the substantially coincident longitudinal axes, to bring locking apertures  101  and  118  into alignment. With the locking apertures aligned, a padlock or other suitable locking device is directed through both locking apertures. Preferably the diameter of aperture  116  exceeds the diameter of pin  102  only slightly, and the diameters of locking apertures  101  and  118  similarly only slightly exceed the captured shaft of the locking device. In that case, the locking device shaft and pin  102  cooperate to prevent any substantial rotation or transverse movement of frame members  88  and  106  relative to one another. Pin  102 , acting in combination with the locking device, considerably strengthens the coupling by preventing the adjacent members from rotating relative to one another about the longitudinal axes.  
         [0046]      FIG. 7  illustrates an alternative embodiment trailer locking system  126  mounted to a trailer  127  similar to trailer  18 . Locking system  126  includes locking frame support structure in the form of two C-shaped support members  128  and  130 . Support member  128  includes a horizontal medial region  132 , and vertical end regions  134  and  136  depending downwardly from opposite ends of the medial region. Similarly, support member  130  includes a medial region  138  and two vertical end regions  140  and  142 .  
         [0047]     A rectangular locking frame of system  126  is composed of a C-shaped front frame member  144 , a C-shaped back frame member  146 , linear side frame members  148  and  150  disposed along a side wall  152  of the trailer including a side door  154 , and a side frame member  156  on the opposite side of the trailer. Adjacent frame members are releasably coupled by coupling plates and locking devices in the manner previously described.  
         [0048]     Locking system  126  is mounted permanently to trailer  127  in the sense that it is secured through mounting structure to the trailer walls using spacers and carriage bolts.  FIG. 8  is a partial sectional view, taken along a vertical plane through the trailer behind support member  130 . A spacer  158 , preferably tubular steel, maintains end region  142  of support member  130  horizontally spaced apart from side wall  152 . Carriage bolts  160  extend through the end region, spacer and side wall to secure these components while locating medial region  138  in vertically spaced apart relation to a roof  162  of the trailer.  
         [0049]     With reference to  FIG. 7 , vertical end region  142  is further secured by a second spacer  164  and carriage bolts  160 . Vertical end region  140  is similarly secured in spaced apart relation to the opposite side wall.  
         [0050]     Vertical end regions  134  and  136  can be secured to the side walls in similar fashion, or alternatively can be equipped with spacers forming a frictional engagement with the trailer side walls. This latter approach allows at least limited sliding or pivoting of vertical end regions  134  and  136  to provide clearance when stabilizing pins are used to couple adjacent frame members.  
         [0051]     Because locking system  126  is substantially permanently attached to trailer  127  rather than supported by the ground, there is no need to disassemble the system to allow the trailer to be moved to another location. The system is transported in place, along with the trailer. Further, medial regions  132  and  138  cooperate to provide a pair of rails extending across the roof of the trailer, to function as a trailer top carrier for transporting equipment and materials, e.g. ladders, pipe sections and lumber. In addition, equipment and supplies can be secured to vertical end regions  134 ,  136 ,  140  and  142  for transport with the trailer.  
         [0052]      FIG. 9  illustrates the rear portion of a trailer  166  equipped with an alternative embodiment trailer locking system  168 . Locking system  168  includes a linear side frame member  170  mounted to a side wall  172  of the trailer by welding the frame member to a tubular steel spacer  174  which is anchored to the side wall using carriage bolts  176 . A linear side frame member  178  is mounted to the opposite side wall in similar fashion. The locking system further includes a C-shaped frame member  180  including a medial region  182  and opposed, parallel end regions  184  and  186 . To secure the trailer against entry through rear doors  188  and  190 , end regions  184  and  186  are releasably coupled to side frame members  170  and,  178  in the manner previously described.  
         [0053]      FIG. 10  illustrates a further alternative embodiment trailer locking system  192  for securing a side door  194  of a trailer  196 . The locking system includes a relatively short linear frame member  198  and a similar frame member  200 , mounted to a side wall  202  of the trailer with carriage bolts directed through respective mounting plates  204  and  206 . A C-shaped frame member  208  includes opposite end regions attached releasably to frame members  198  and  200  in the manner previously described. The frame member secures side door  194 , yet also provides clearance for hardware such as the latching bar and hinges.  
         [0054]      FIG. 11  illustrates an alternative embodiment coupling plate  210  attached to the end of a frame member  212 . Coupling plate  210  is formed with two locking apertures  214  and  216 . Frame member  212 , and an adjacent frame member having a similar coupling plate, are releasably secured to one another with two locking devices. With reference to  FIG. 7 , an advantage of this coupling approach is that no clearance is required for stabilizing pin, for example when inserting or removing frame member  150  to prevent or allow the opening of side door  154 .  
         [0055]      FIG. 12  illustrates a hinge  218  for coupling adjacent frame members  220  and  222 . In any of the foregoing locking systems, hinged couplings can be employed in lieu of the coupling plate/stabilizing pin arrangements, to reduce the number of padlocks or other locking devices required. In locking systems  168  and  192 , only one of the coupling plate/pin arrangements can be replaced with a hinge, while several hinges can be substituted into each of systems  16  and  126 .  
         [0056]     Thus in accordance with the present invention, trailer locking systems can reduce the risk of unauthorized entry, can be used to secure different trailers within a given size range, and are convenient to use. The locking systems include embodiments that require no mounting of hardware or other modifications to the trailer, and other embodiments in which the locking system also functions as a carrier.

Technology Classification (CPC): 4