Abstract:
The present invention provides a method and kit for assembling a high security latch and lock assembly for an upwardly acting cargo container door. More specifically, the instant invention provides a secure and transferable lock assembly engagable with a preexisting cargo container latch assembly for holding the latch handle in the latched position.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a method and kit for modifying a pre-existing cargo container latch assembly for an upwardly acting door to accept a high security sliding bolt lock.  
       BACKGROUND OF THE INVENTION  
       [0002]     Cargo carrying vehicles, e.g. box trucks, tractor trailers and the like, that traverse public roadways are constantly subjected to the danger of cargo theft. Most cargo thefts occur when the truck is parked, such as at a truck stop, rest area or café. However, thieves are constantly devising new methods of stealing cargo, and thefts may now occur while the vehicle is in motion. These thefts result in losses to the vehicle owner, the insurance carrier, and indirectly to the public at large.  
         [0003]     One of the most common door and latch combinations includes an upwardly acting door having a pivoting latch as is taught in U.S. Pat. No. 3,642,314.  
         [0004]     Persons familiar with the manufacture, installation and maintenance of doors, particularly upward acting tractor trailer type doors, have long been aware that the latch structures of such doors are subject to unusually rough treatment, even under substantially normal operating conditions. Container doors and their lock structures are constantly exposed to the weather and are often strained by the loads carried in the container or battered by external obstructions. In addition the latches and doors are often the subject of attempted unauthorized entry.  
         [0005]     In order to prevent unauthorized entry into the cargo area of a van or truck, the trucking industry has in the past employed numerous varieties of doors and latching mechanisms. Generally, the door and latch structure is provided with some type of locking mechanism, typically a padlock having a U-shaped shackle, which releasably holds the door latch handle in the engaged position.  
         [0006]     For example, U.S. Pat. No. 3,740,978, teaches a latch and lock assembly for use on an overhead type cargo door. The assembly includes a catch pin mounted to the bed portion of the truck or similar vehicle and a latch mechanism mounted upon the lower portion of the truck or van door. The latch mechanism includes an elongated handle pivotally mounted upon the lower portion of the door. The handle includes a C-shaped portion on its distal end which cooperates with the locking assembly. The lock assembly includes a bracket that is mounted to the lower portion of the door. The bracket is constructed having a generally rectangular shape with one closed end wall. Attached to the closed end wall is a pair of steel rods which take the place of a standard U-shaped padlock shackle. The padlock body is attached to the steel rods in a conventional manner to allow limited movement of the body. In operation the latch handle is rotated to latch the door and the lower end of the C-shaped portion of the handle passes between the lock shackles. The lock body can thereafter be pushed inwardly to engage the lock thereby locking the door in place. The lock body is releasable by a key; after release the lever can be moved into a release position and the door opened.  
         [0007]     U.S. Pat. No. 5,737,946 teaches a semi-trailer anti-theft device. The device includes a shield which extends over and substantially encloses both the cargo door latch handle and the padlock. The shield includes an elongated front panel which extends across the latch handle. At one end of the front panel on the rear side is a forked member which can be inserted around the pivot pin of the latch handle to allow the shield to be swung into alignment with the latch handle. The opposite end of the shield is constructed as a padlock guard having a rearwardly extending flange which extends over the top of the padlock and a lock plate covering the face of the padlock. A locking web also extends rearwardly from the front panel below the flange. The locking web includes an aperture arranged to allow the padlock shackle to pass through. In operation, the forked end of the shield is slid over the pin of a latched door lever and rotated downwardly until the padlock can be slid through the handle and the locking web.  
         [0008]     U.S. Pat. No. 6,058,745, teaches a padlock cover assembly for covering U-shaped shackle padlocks on latching and locking doors. The elongated boxlike cover is secured to one of doors via a pivoting hinge which allows the cover to pivot along two axis. A padlock mounting bracket is secured to the second door. In operation, an unlocked padlock is placed through the mounting bracket. The cover is rotated over the unlocked padlock and pushed upward to engage the padlock. As the padlock is engaged a pawl formed on the back of the cover is advanced between the padlock shackle and the upper surface of the padlock body. As the cover is pivoted to advance the padlock to a closed position, the pawl extends into interlocking engagement with the shackle of the padlock. To unlock the padlock, the cover is provided with an aperture in its lower portion for access with a key.  
         [0009]     The U-shaped shackle padlocks utilized in the prior art are easily cut with readily available bolt cutters or frozen and broken with a compressed gas source, such as a fire extinguisher. In addition, because the padlocks are not attached to the trailer door they are often misappropriated or lost. Accordingly, the cost of padlock replacement often reaches thousands of dollars per year for an average size trucking company.  
         [0010]     The prior art has also suggested the use of latching mechanisms constructed specifically for attachment to the container door. For example, U.S. Pat. No. 3,893,722, discloses a latch and lock assembly for use on an overhead type cargo door. The assembly includes a catch pin mounted to the bed portion of the truck or similar vehicle and a latch mechanism mounted upon the lower portion of the truck or van door. The latch mechanism includes an elongated handle pivotally mounted upon the lower portion of the door. The handle includes a C-shaped portion on its distal end which cooperates with the locking mechanism. The locking assembly is mounted to the lower portion of the door within a box type bracket. Within the bracket is a spring loaded lever and a keyed cylinder. In operation the latch handle is rotated to latch the door and the C-shaped portion of the handle engages the spring loaded lever to lock the door in place. To release the lever a key is used to rotate the spring loaded lever into a disengaged position, allowing the handle to be rotated.  
         [0011]     Latching mechanisms such as the one described above often become inoperable due to the rough treatment which truck doors receive and, as a result of the one piece construction they require replacement of the entire latch mechanism for repair. In addition, it is often desirable for a driver to transfer a lock from one cargo container to another to minimize the number of persons that have access to keys for a locking mechanism, an impossible task for a one piece lock and latch mechanism. The one piece devices become cumbersome, requiring transference of the latch keys with each transfer of the container.  
         [0012]     Accordingly, what is lacking in the prior art is a cost effective locking assembly for use with an upwardly acting cargo container door. The locking assembly should achieve objectives such as reliable security and lock tranferability. The locking assembly should include packaging flexibility for installation on various trailer door configurations with minimal modification of the original latching mechanism. The lock should be capable of withstanding the harsh environment of the trucking industry and should allow for easy replacement and repair.  
       SUMMARY OF THE INVENTION  
       [0013]     The present invention provides a method and kit for assembling a high security latch and lock assembly for an upwardly acting cargo container door. More specifically, the instant invention provides a secure and transferable lock assembly engagable with a preexisting cargo container latch assembly for holding the latch handle in the latched position.  
         [0014]     Cargo containers for truck use generally include a bed portion, a left side wall, a right side wall, a front wall, a roof panel and an upward acting door. The upward acting door is generally comprised of a plurality of horizontally hinged sections which are disposed in a substantially vertical plane when the door is closed, and in a substantially horizontal plane near the roof panel when the door is open. Pivotally mounted upon a lower portion of the upward acting cargo container door is a latch. The latch typically includes a backing plate secured to the rear surface adjacent a lower portion of the door. The backing plate includes an axle secured thereto and a hub rotatably supported on the axle. An elongated handle and an arcuate catch are secured or integrally formed to the hub with the handle extending substantially radially from the hub. The distal end of the handle includes an integrally formed depending tab having an aperture drilled generally parallel to the handle. The arcuate catch extends from the hub and is adapted to cooperate with a catch pin mounted to the bed portion of the cargo container. The latch is manually rotatable between a latched position and an unlatched position. A latched keeper includes an integral hub pivotally mounted on a pivot pin secured to the backing plate; the latched keeper having a downwardly and frontwardly projecting flange integrally formed on its hub, the flange having an opening which aligns with the aperture in the depending tab of the handle when the latch is in the latched position, for receiving a conventional U-shaped shackle padlock.  
         [0015]     The instant invention modifies the latch mechanism described above to include a sliding bolt lock by removing the latched keeper from the backing plate and positioning a sliding bolt lock adjacent to the distal end of the handle when the handle is in a latched position so that the sliding bolt portion of the sliding bolt lock engages the handle to prevent rotation thereof in a locked position. The sliding bolt lock can then be secured to the lower portion of the door utilizing a plurality of L-shaped tabs secured to the body portion of the sliding bolt lock. The L-shaped tabs each include a vertical portion and a horizontal portion, wherein the vertical portion is secured to the body portion of the sliding bolt lock and the horizontal portion includes at least one aperture therethrough. The tabs may be attached to the backing plate with standard fasteners or weldments.  
         [0016]     In an alternative embodiment the sliding bolt lock may be supplied with a casing for releasably securing the sliding bolt lock adjacent to the end portion of the handle. The casing would include an inner surface and an outer surface with the inner surface having a conjugate shape to the body portion of the sliding bolt lock. The casing also includes a small aperture which is adapted to cooperate with a spring pin built into the body of the lock. Depressing the spring pin while the sliding bolt is in an unlocked position allows the lock to be inserted or removed from the casing. A plurality of L-shaped tabs are secured to the outer surface of the casing for attachment to the lower portion of the door. Each of the L-shaped tabs include a vertical portion and a horizontal portion, wherein the vertical portion is secured or integrally formed onto the outer surface of the casing and the horizontal portion includes at least one aperture therethrough. The tabs may be attached to the backing plate with standard fasteners or weldments.  
         [0017]     Accordingly, it is an objective of the present invention to provide a kit for improving the security provided by a latch and lock structure for an upwardly acting cargo container door.  
         [0018]     Another objective of the present invention is to provide a method for improving the security provided by a latch and lock structure for an upwardly acting cargo container door.  
         [0019]     An additional objective of the present invention is to provide a lock mechanism for an upwardly acting cargo container door which prevents pilferage of the lock mechanism and minimizes the possibility for unauthorized opening of the lock.  
         [0020]     Yet another objective of the present invention is to provide a lock kit for an upwardly acting cargo container door that allows lock portability while minimizing the possibility of lock misappropriation and/or loss.  
         [0021]     Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.  
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0022]      FIG. 1  is a front view partially in section illustrating a prior art latch mechanism for an upwardly acting cargo container door;  
         [0023]      FIG. 2  is a front view partially in section illustrating one embodiment of the modified latch mechanism of the present invention;  
         [0024]      FIG. 3  is a top view partially in section illustrating a top view of the modified latch mechanism of the present invention;  FIG. 4  is a section view along lines  1 - 1  of  FIG. 2  illustrating the cooperative engagement between the handle and the sliding bolt lock of the present invention;  
         [0025]      FIG. 5  is a front view partially in section and partially exploded illustrating an alternative embodiment of the present invention  FIG. 6  is an end view of the alternative embodiment illustrated in  FIG. 5 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]     Although the invention is described in terms of a preferred specific embodiment, it will be readily apparent to those skilled in this art that various modifications, rearrangements and substitutions can be made without departing from the spirit of the invention. The scope of the invention is defined by the claims appended hereto.  
         [0027]     Referring to  FIG. 1 , the latch and door structure utilized in the instant invention is comprised of a latch assembly  10  mounted on the lower portion of an upwardly acting door  12  for engagement with a catch pin assembly  14  that is mounted in the bed  16  of a conventional cargo container for a truck or van. The door  12  is generally comprised of a plurality of horizontally hinged sections which are disposed in a substantially vertical plane, when the door  12  is closed, and in a substantially horizontal plane near the roof of the van when the door is open. A resiliently flexible weather seal  18  is mounted on the lower edge of the door  12  and is engageable with the bed  16  in a conventional manner for conventional purposes.  
         [0028]     Still referring to  FIG. 1 , the catch pin assembly  14  is comprised of an elongated, substantially rectangular casing  20  having a top flange  22 , a pair of side walls  24  (only the back being shown) and a pair of end walls  26  and  27  and a catch pin  34 . The side walls and the end walls define a catch chamber  28  which preferably opens upward to receive the latch  30  and downwardly for drainage.  
         [0029]     The top flange  22  preferably extends beyond both end walls  26 ,  27  and the back sidewall  24  for engagement with the upper surface  32  of the bed  16  when the casing  20  is located within the opening in the bed  16 . The top flange  22  may be secured to the bed  16  by welding, screws or any other conventional means. The catch pin  34  is secured to and extends between the sidewalls  24  of the casing  20  about midway between the end walls  26  and  27 .  
         [0030]     The latch assembly  10  has a backing plate  36  which is secured to the rear surface of the door  12  adjacent the lower edge thereof by conventional means such as bolts, rivets or weldment. Rigidly secured to the backing plate  36  is axle  38  defining an axis of rotation for the handle  40  and the catch  30 . The handle  40  and the catch  30  are rotatably supported on axle  38  to allow pivotal movement between a latched and an unlatched position. The handle  40  extends substantially radially from hub  42 . The distal end  44  of the handle includes an integrally formed depending tab  46  having an aperture  48  drilled generally parallel to the handle. Also extending from the hub  42  is an elongated arcuate hook  30  having a slightly cammed inner surface  50 . An unlatched keeper  52  is pivotally mounted upon a pivot pin  54  which is rigidly mounted to the backing plate  36 . The keeper  52  has a hook  56  at one end which is engageable with the hub  42  to maintain the latch means in an unlatched position.  
         [0031]     A latched keeper  58  is substantially flat and has an integral hub  60  pivotally mounted on pivot pin  62 . The pivot pin is rigidly secured to the backing plate  36 . A downwardly and frontwardly projecting flange  64  is integrally formed on the hub  60 . The flange has an opening  66  which aligns with aperture  48  in the depending tab  46  of handle  40  when the latch means is in a latched position, for receiving a conventional U-shaped shackle lock  66 .  
         [0032]     Referring to  FIGS. 1 through 3 , in order to alleviate the problems associated with cargo theft from cargo containers having upward acting doors, the present invention provides a method and kit for modifying the pivoting latch as set forth in  FIG. 1 . The method of modification generally includes removing the latched keeper  58  from the backing plate  36  by conventional means such as grinding, torch, drilling or the like. Thereafter, attaching the sliding bolt lock  70  of the instant invention kit to the backing plate  36  adjacent to the distal end portion  44  of the handle  40  when the handle is in the latched position. The sliding bolt lock  70  comprises a body portion  72  and a sliding bolt member  74 , the sliding bolt member being movable between a locked position and an unlocked position. Moving the sliding bolt member between the locked and the unlocked positions engages and disengages respectively the aperture  48  in the depending tab  46  when the handle  40  is in the latched position for positively preventing movement or allowing movement respectively of the handle. The sliding bolt lock  70  may include safety features such as multi-element pin assemblies and/or cooperating computer chips in the lock cylinder and/or key. Each lock may also include an ownership identification card (not shown) that includes information required to make additional keys and/or digital information required to open the sliding bolt lock. Such sliding bolt locks are sold by Cisa Inc. of Chicago, Ill. and Mul-T-Lock Ltd of Yavne, Israel.  
         [0033]     For securing the sliding bolt lock  70  to the backing plate  36 , a plurality of L-shaped tabs  76  may be secured to the body portion  72  of the lock. Each of the L-shaped tabs  76  include a vertical portion  78  and a horizontal portion  80 . The vertical portions  78  are preferably secured to the body portion  72  of the sliding bolt lock by welding; alternatively, other means well known in the art such as rivets or threaded fasteners may be utilized. In a further alternative embodiment the tabs  76  may be integrally formed to the lock body  72 . The horizontal portion  80  of the tabs  76  includes at least one aperture  82  therethrough for attachment to the lower portion of the upwardly acting door  12 . The horizontal portion  80  of the tabs  76  are preferably attached to the lower portion of the door via carriage type bolts  84 . Alternatively, other fasteners and/or weldments well known in the art may be utilized to secure the tabs to the backing plate  36  and/or the lower portion of the door  12 .  
         [0034]     Referring to  FIGS. 5 and 6 , an alternative embodiment the lock is assembly is provided with a lock casing  90  for releasably securing the sliding bolt lock  70  ( FIG. 2 ) adjacent to the end portion  44  of the handle  40 . The lock casing  90  includes an inner surface  92  and an outer surface  98 , the inner surface  92  having a generally conjugate shape to the body portion  72  of the sliding bolt lock. The lock casing  90  includes an aperture  100 , the aperture is adapted to cooperate with a spring pin  102  incorporated into the body portion  72  of the sliding bolt lock. Depressing the spring pin  102 , allows the body portion  72  to be removed from the lock casing  90  when the sliding bolt  74  is in an open position, yet secures the lock body within the lock casing  90  to prevent accidental loss or misappropriation when the sliding bolt  74  is in a locked position. The outer surface  98  of the lock casing  90  includes a plurality of L-shaped tabs  76  secured thereto, the L-shaped tabs being constructed and arranged for attachment to a lower portion of the upwardly acting door  12 . Preferably each of the L-shaped tabs include a vertical portion  78  and a horizontal portion  80 , wherein the vertical portion  78  is preferrably secured to the outer surface  98  of the lock casing  90  via weldment and the horizontal portion  80  includes at least one aperture  82  therethrough. In further alternative embodiments, other means well known in the art such as rivets or threaded fasteners may be utilized to attach the vertical portion of the L-shaped tabs to the outer surface  98  of the lock casing  90 . In a further alternative embodiment, the L-shaped tabs  76  may be integrally formed onto the lock casing  90 . In the preferred embodiments the casing may be constructed of materials well known in the art which may include, but should not be limited to metals such as steel, hardened steel, armor plated steel, aluminum, titanium and the like.  
         [0035]     All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.  
         [0036]     It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification.  
         [0037]     One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.