Patent Publication Number: US-6655904-B2

Title: Method of off-loading a container from a tilt bed trailer

Description:
RELATED APPLICATIONS 
     This application is a continuation of prior co-pending application Ser. No. 09/858,375 filed May 16, 2001, which is a divisional of prior application Ser. No. 09/422,908 filed Oct. 21, 1999, now U.S. Pat. No. 6,406,231, which is a continuation-in-part of Ser. No. 09/084,126 filed May 22, 1998, now U.S. Pat. No. 6,126,378. 
    
    
     TECHNICAL FIELD 
     This invention relates to trailers and trailer accessories and, more particularly, to trailer and trailer accessories for loading, transporting, and off loading rectangular, International Standard Organization (ISO) containers having ISO corner fittings. 
     In preferred forms, this invention relates to container lockdown devices and wheel assemblies and, more particularly, to container lockdown devices which secure containers to trailers with the wheel assemblies attached to the trailers and methods for loading and unloading the containers therewith. 
     BACKGROUND 
     Containers constructed with dimensions according to the International Standards Organization (ISO containers) are commonly transported by tractor trailers. ISO containers typically come in lengths of twenty and forty feet, and each container has eight corners with each corner including a corner fitting. The corner fittings include an opening on each of the three exposed faces. Various components are attached to the corner fittings to lift, move, load, lockdown, and off-load the ISO containers. These components are generally bulky, complex, expensive to manufacture, and difficult to use requiring several people, or the addition of extensive equipment, to perform a task such as loading. Further, the ground surface over which containers are being loaded or off-loaded is sometimes damaged. It is also necessary during loading and unloading to remove and replace many of these components thereby increasing the labor required and time necessary to load and unload ISO containers. Further, the frequency of use and kinds of uses for ISO containers are continually increasing. For example, ISO containers are now used for anything from typical transportation and storage to mobile office space. Hence, the disadvantages of these components are becoming more acute and have a greater cost impact every day. 
     Trailer loading and off loading components are of special significance. Containers are frequently loaded onto trailers when oriented at an angle to the trailer. The various trailer accessories currently available lack the ability to align ISO containers with the trailer, so that loading and off loading are overly time consuming and require two or more people to complete the task. Conventionally, trailers are provided with a single winch fixed at a central location near the front of the trailer. The single winch lacks the ability to align the container during loading and is unable to aide in performing other functions such as off loading. Substantial advancements have been made in tilting trailers to load/unload containers by shifting the undercarriage of the trailer as taught by U.S. Pat. Nos. 5,211,413 and 5,013,056 and trailer side shifting for alignment to payload as taught by U.S. Pat. No. 4,746,261 which are hereby fully incorporated herein by reference. However, these references generally do not address alignment problems that occur while loading/unloading ISO containers from the trailer bed. 
     Another problem is presented when loading two twenty foot containers on the same trailer. When the front twenty foot container has been loaded onto a trailer, the centrally located winch is not positioned to efficiently pull the rear twenty foot container onto the trailer behind the front container. 
     When loading and unloading ISO containers without the aid of a crane, it is standard to attach wheel assemblies to the lower corners of the containers. However, it is typically necessary to remove the wheel assemblies from the containers during transport. Wheel assembly removal is necessary because of their bulk and the space constraints on the trailers and because the wheel assemblies make it more difficult to safely and efficiently secure the ISO containers to the trailers. 
     SUMMARY OF THE INVENTION 
     Accordingly, one important object of the present invention is to provide an improved winch assembly having an increased ability to align containers as they are loaded. 
     It is an additional important object of the present invention to provide improved methods of loading and off loading containers which reduce time and labor for loading and off loading. 
     It is also an important object of the present invention to provide an improved wheel assembly for loading and moving containers. 
     It is also an important object of the present invention to provide an improved method for raising and lowering containers on wheel assemblies. 
     It is another important object of the present invention to provide improved off loading pulleys for use with a winch assembly to off-load containers. 
     It is still another important object of the present invention to provide an improved off-load foot for off loading containers. 
     It is a further important object of the present invention to provide an improved cable guide for aligning containers as they are loaded. 
     It is a still further important object of the present invention to provide improved container guides for aligning containers as they are loaded and off loaded. 
     It is yet another important object of the present invention to provide an improved lockdown mechanism for holding containers in place after they are loaded. 
     In carrying out the foregoing and other objects, the present invention contemplates an improved trailer with an improved trailer winch assembly having a movable winch apparatus. A winch transport assembly operates to move the winch apparatus to a desired position, and a control mechanism is provided to operate the winch apparatus and control mechanism. 
     In a preferred embodiment, the winch transport assembly comprises an extendable arm with the winch apparatus attached to the winch arm adjacent an outer end of the winch arm. The winch arm is slidably received in a guide shell centrally located on the deck of the trailer. Preferably, a second winch apparatus is provided on a second winch arm slidably received in the guide shell to move the second winch assembly preferably in an opposite direction relative to the first winch assembly. 
     The present invention also contemplates an improved method for loading containers onto trailers. The winch apparatus is moved to a desired position, and a winch cable is connected to a front corner of the container. The winch apparatus is then activated to pull the deck under the container. 
     In a preferred embodiment, moving the winch apparatus comprises moving the winch apparatus beyond the side of the trailer deck. Also, a second winch apparatus is preferably moved by the transport assembly beyond the other side of the trailer deck. To load a second container, the winch cables of the two winch apparatus are connected to the front corners of the second container. With the winch apparatuses extended beyond the sides of the trailer deck, the cables extend beside the first container to pull the second container onto the trailer deck without interference from the first container. To further enhance the loading process, the trailer is initially rolled underneath the container which remains substantially stationary until it is almost entirely on the trailer. 
     The present invention further contemplates an improved wheel assembly for attachment to the corner fittings of ISO containers. The wheel assembly comprises a rigid wheel frame and a wheel rotatably and slidably supported in the wheel frame. The wheel frame slides between lowered and raised positions relative to the wheel, and an attachment assembly is utilized to attach the wheel frame to the corner fitting of the ISO container. 
     In a preferred embodiment, the wheel assembly includes a jack plate spaced apart from the wheel to define a jack receiving area between the wheel and the jack plate. The preferred embodiment also includes a lock block which is received into a lock slot of the wheel frame to hold the wheel frame in the raised position. The attachment assembly includes an attachment block onto which the wheel frame is slidably mounted for quick removal of the wheel frame from the attachment block. 
     The present invention still further contemplates an improved method for raising ISO containers with a jack and the wheel assembly. In the method, the jack is operatively positioned between the wheel and the jack plate, and the jack is activated to move the jack plate relative to the wheel. The lock block is then preferably inserted into the lock slot to hold the wheel in the raised position. 
     The present invention also contemplates an improved trailer including an inversion member. The winch cable extends around the inversion member and connects to the container to alter the pulling direction of the trailer winch apparatus. With the pulling direction of the winch apparatus changed, the winch apparatus operates to pull the container off the deck of the trailer. 
     In a preferred embodiment, the inversion member comprises a rotatable inversion pulley having a cable groove formed in its perimeter. Preferably, the inversion pulley is removably connected to a side flange of the deck and substantially inverts the pulling direction of the winch apparatus. The preferred embodiment further includes a second inversion member with the first and second inversion members being positioned at the same point along the length of the trailer. For unloading two twenty foot containers, third and fourth inversion members are preferably provided at a desired location along the length of the trailer different than the location along the length of the trailer for the first and second inversion members. 
     The present invention further contemplates an improved method for off loading containers from a trailer. In the method, the winch cable is extended around the inversion member, and the free end of the winch cable is removably attached to the container. The winch apparatus is then activated to pull the container off the deck of the trailer. 
     In a preferred embodiment utilizing two winch cables and where two twenty foot containers are located on the trailer, the winch cables are first extended around the first and second inversion members to off-load the rear container. Then the winch cables are extended around the third and forth inversion members to off-load the front container. 
     The present invention still further contemplates an improved off-load foot for use in loading an ISO container onto a trailer and in off loading an ISO container from a trailer. The off-load foot includes an attachment assembly for connection to a corner fitting of the ISO container, and a downwardly extending leg having an upper end connected to the attachment assembly and a ground end for engaging the ground surface. 
     In a preferred embodiment, the off-load foot also includes a base connected to the ground end of the leg. The edges of the base are turned up allowing the off-load foot to rock on the ground surface without damaging the ground surface. 
     The present invention also contemplates an improved method for off loading a container with the off-load foot. In the method, the off-load foot is attached to the corner fitting of the ISO container; the back end of the trailer is lowered until the ground end of the off-load foot securely contacts the ground surface lifting the end of the container off the back end of the trailer, and the trailer is pulled forward. 
     In a preferred embodiment, the back end of the trailer is lifted again, so that the off-load foot can be removed. After the off-load foot is removed, the back end of the trailer is lowered until the rear of the container contacts the ground surface, and then the trailer is pulled from underneath the container. 
     In another preferred embodiment, the preferred off-load foot is utilized during the last several feet of pulling a trailer with a cambered/arced deck under a 40 foot container, to keep from dragging the container bottom on the trailer. The rear of the trailer is lifted, and an off-load foot is attached to each rear corner of the container. The rear of the trailer is then lowered until the ground end of the off-load foot securely contacts the ground surface and lifts the rear of the container off the camber of the trailer. The trailer is then be pulled under the container to a loaded position. 
     The present invention also contemplates an improved cable guide in combination with a trailer having a winch apparatus and stake holes formed in the trailer deck. The roller guide includes a stake-hole post placed into one of the stake holes. With the stake-hole post in place, a guide portion of the cable guide is located above the deck and receives the winch cable to alter the pulling direction of the winch apparatus. 
     In a preferred embodiment, the guide portion is rotatably connected to the stake-hole post for rotation by the winch cable. Preferably, the guide portion is a circular disk with a cable receiving groove formed in its perimeter. 
     The present invention further contemplates an improved container guide for guiding and aligning a container especially during loading. The container guide includes an attachment mechanism for attaching a container guide body to the container and a winch cable attachment assembly for connecting a free end of the winch cable to the container guide body. The container guide also includes an elongated downwardly extending member having a length sufficient to extend below the surface of the deck and engage the sides of the deck. 
     In a preferred embodiment, the container guide body comprises two legs with one of the legs being the elongated member and the other leg having an aperture for attachment to a free end of the winch cable. Preferably, the elongated member also comprises an aperture for attachment to the free end of the winch cable, so that the container guide body is attachable in two configurations. 
     In another preferred embodiment, the attachment mechanism comprises a twist lock tab for locking in an opening of one of the corner fittings of the container. In this embodiment, the elongated member comprises a guide pin extending through a guide pin aperture in the container guide body. The pin is preferably cylindrical and rotatably received in the guide pin aperture. 
     The present invention still further contemplates an improved lockdown mechanism for holding a container on the trailer. The lockdown mechanism includes an attachment member for attaching to the container, a pivotal securement member for attaching to the deck and an extension member attached to both the attachment member and the securement member when the securement member is pivoted to a lockdown position. The securement member is preferably attached to an outer face of the side flange of the trailer deck, and the securement member preferably extends beyond the side flange to connect with the extension member. Thus, the extension member is positioned beyond the side flange of the deck. 
     In a preferred embodiment, the extension member comprises a substantially cylindrical pin extending through cylindrical openings in the attachment member and the securement member. Preferably, the extension member is substantially perpendicular to both the attachment member and the securement member. Further, a locking member is provided to hold the securement member in the lockdown position. 
     A further important object of the present invention is to provide an improved wheel assembly which can be attached to an ISO container during transport on a trailer. 
     It is another important object of the present invention to provide an improved lockdown mechanism which can secure an ISO container having wheel assemblies attached thereto during transport on a trailer. 
     It is still another important object of the present invention to provide an improved loading/off-loading container foot which can remain attached to an ISO container during transport on a trailer. 
     It is further an important object of the present invention to provide improved methods requiring less time and labor for loading and unloading ISO containers onto and off of trailers. 
     In carrying out the foregoing and other objects, the present invention contemplates an improved bottom wheel assembly for attachment to a container. The bottom wheel assembly includes a mounting bracket which attaches the assembly to the container, and at least one wheel rotatably connected to the mounting bracket. The mounting bracket and wheel, no matter which direction the container is moved, are always positioned below the container and inside of the extremities of the container. 
     In a preferred embodiment, the wheel comprises a non-castering wheel, and the mounting bracket comprises opposed components defining an upper pair of aligned lock pin openings and a lower pair of aligned wheel axle openings. The mounting bracket also has positioning shoulders sized to properly position the lock pin openings in an ISO container corner fitting. Preferably, the wheel assembly has three wheels and a lockdown extension extending from a wheel axle which extends through the wheel axle openings to mount the wheels to the mounting bracket. The wheel axle preferably includes a threaded lockdown extension and rounded lockdown extensions which cooperate with different lockdown brackets to secure the container to a trailer. 
     It is further contemplated that the described wheel assembly will be used in combination with a lockdown bracket, including a lockdown securement portion, and a trailer attachment portion. The lockdown securement portion attaches to the lockdown extension and to the trailer attachment portion thereby securing the container to the trailer. 
     In a preferred embodiment, the lockdown securement portion includes a lockdown flange defining an opening for receiving the lockdown extension therethrough and a threaded lockdown extension connector which is threadably connected to the threaded lockdown extension. The trailer attachment portion includes a pair of trailer clips attached to opposite ends of the lockdown flange and a central abutment block for fixed attachment to a trailer. The trailer clips are positioned on opposite sides of the central abutment block to secure the container to the trailer. 
     In another preferred embodiment, the lockdown securement portion comprises a pair of upper legs which receive the rounded lockdown extension between the upper legs and an upper surface of a trailer deck. Preferably, a pair of lower legs are positioned beneath the upper legs to hold the rounded lockdown extension between the upper and lower legs. The upper legs are somewhat movable, so that they are forced upwardly by the rounded lockdown extension as the rounded lockdown extension is forced into place between the upper and lower legs. The trailer attachment portion preferably comprises a stake hole connector attachable to a stake hole in the trailer deck. The stake hole connector includes a top plate mounted on top of the deck and a stake hole arm extending downwardly from the top plate through the stake hole. A bottom plate secures the stake hole arm in the stake hole. 
     The present invention further contemplates that the above described wheel assembly will be used in combination with a container. The container is preferably a rectangular ISO container having two front corner fittings and two rear corner fittings. It is further contemplated that the above described lockdown brackets will be used in combination with both the wheel assembly and the container. 
     It is still further contemplated in the present invention that the above described wheel assembly, container, and lockdown brackets will be used in combination with a trailer. The trailer preferably includes a trailer deck for supporting containers and a plurality of wheels rotatably coupled with the deck. 
     The invention is further directed to a novel lockdown mechanism for securing a container to a trailer. The mechanism includes a lockdown extension attachable to a container and a lockdown securement portion selectively connectable to the lockdown extension. A trailer attachment portion connects the lockdown securement portion to the trailer. 
     In a preferred embodiment, the lockdown extension comprises a wheel axle having a threaded front lockdown area and a rounded side lockdown area. In one preferred embodiment, the securement portion includes a lockdown flange and threaded lockdown extension connector as described above. The trailer attachment portion includes the above described clips and the central abutment block for fixed attachment to a trailer. Similarly, the trailer clips are positioned on opposite sides of the central abutment block to secure the container to the trailer. 
     In another preferred embodiment, the lockdown securement portion comprises the above described upper and lower legs which receive the rounded lockdown extension therebetween. The trailer attachment portion preferably comprises the above described stake hole connector attachable to a stake hole in the trailer deck. 
     The invention is further directed to a container foot having a substantially rigid foot mounting bracket for attachment to the container. A platform is pivotally attached to the foot mounting bracket. 
     In a preferred embodiment, the platform is a substantially flat, rectangular plate, and the foot mounting bracket and platform are positioned below the container and within the extremities of the container when attached to the container. The container foot is preferably used in combination with the container and a trailer having a deck that defines a container foot receiving slot having the foot mounting bracket held in the foot receiving slot. The foot receiving slot includes a widening mouth for guiding the foot mounting bracket into the container foot receiving slot, and the receiving slot is sized to securely hold the foot mounting bracket. With the foot mounting bracket securely held in the foot receiving slot, the container foot acts as a lockdown for the container. 
     The invention is still further directed to a novel mounting bracket for mounting various components onto a container. The mounting bracket includes a shoulder portion or mounting the bracket on the container and a substantially rigid attachment portion for having a selected one of a plurality components attached thereto. 
     In a preferred embodiment, the component is selected from a group comprising a container foot, a wheel assembly, and a lockdown extension. The attachment portion defines an opening having a key way, and one of the components includes a key received in the key way to fix that component from rotation. The shoulder is sized to properly position the mounting bracket relative to the container. 
     The invention is also directed to a novel trailer for transporting containers. The trailer includes a flat deck for supporting containers, and the deck has a front end, a back end, and opposed sides. A plurality of wheels are rotatably coupled with the deck and a hitch assembly is provided for hitching the deck to a towing vehicle. Preferably, the trailer also includes a pair of container foot receiving slots defined in the back end of the trailer. Additionally, the trailer preferably includes at least one of the above described lockdown brackets attached to the deck. 
     The invention also pertains to a method for loading containers on trailers. To load the containers, wheel assemblies are attached to two front corner fittings of the container and the container is pulled onto the trailer with a winch assembly. The wheel assemblies are left attached to the container, and the container is secured to the trailer with lockdown mechanisms for transport. 
     In a preferred embodiment, the method further comprises attaching container feet to the rear corner fittings of the container and inserting the container feet into container foot receiving slots formed in the back end of the trailer. For some containers, wheel assemblies are also attached to the two rear corner fittings of the container and left attached for transport. Preferably, securing the container to the trailer comprises connecting lockdown brackets to lockdown extensions of the wheel axles of the wheel assemblies. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a trailer including features according to the present invention; 
     FIG. 2 is a fragmentary, enlarged perspective view of a front end of the trailer of FIG. 1; 
     FIG. 3 is a fragmentary, top plan view of a cable guide inserted in the trailer of FIG.  1  and illustrating the operation of the cable guide to align a container with the trailer; 
     FIG. 4 is a fragmentary perspective view of the cable guide of FIG. 3; 
     FIG. 5 is a fragmentary perspective view illustrating the operation of a container guide; 
     FIG. 6 is a fragmentary perspective view illustrating the operation of the cable guide of FIG.  3  and an alternate embodiment of a container guide; 
     FIG. 7 is a top view in partial cross-section of a winch assembly according to the present invention shown in an extended position; 
     FIG. 8 is a cable side view in partial cross section of the winch assembly of FIG. 7 shown in the extended position; 
     FIG. 9 is an end view of the winch assembly of FIG. 7 taken from the perspective of line  9 — 9  in FIG. 8; 
     FIG. 10 is an opposite end view of the winch assembly of FIG. 7 taken from the perspective of line  10 — 10  in FIG. 8; 
     FIG. 11 is a fragmentary front view of the winch assembly of FIG. 7 taken from the perspective of line  11 — 11  in FIG. 9; 
     FIG. 12 is a top view of the winch assembly of FIG. 7 shown in a retracted position; 
     FIG. 13 is a cable side view of the winch assembly of FIG. 7 having portions removed for illustration and shown in the retracted position; 
     FIG. 14 is an exploded perspective view of a wheel assembly according to the present invention and the container guide of FIG. 5; 
     FIG. 15 is a partially exploded perspective view of the wheel assembly of FIG. 14; 
     FIG. 16 is an exploded perspective view of the alternate embodiment of the container guide assembly of FIG. 6; 
     FIG. 17 is a side view in partial cross section of the wheel assembly of FIG. 14 illustrating the wheel assembly in a lowered position and placement of a jack in the wheel assembly; 
     FIG. 18 is a front view in partial cross section of the wheel assembly of FIG. 14 in the lowered position; 
     FIG. 19 is a side view in partial cross section of the wheel assembly of FIG. 14 having a portion thereof removed to illustrate actuation of the jack and illustrating the wheel assembly in a raised position; 
     FIG. 20 is a front view in partial cross section of the wheel assembly of FIG. 14 in the raised position; 
     FIG. 21 is a side view of the wheel assembly of FIG.  14  and illustrating the container being loaded; 
     FIG. 22 is a side view of the wheel assembly of FIG.  14  and illustrating the operation of the container guide of FIG. 5; 
     FIG. 23 is a side view of the wheel assembly and container guide of FIG.  14  and illustrating a loaded position of the container; 
     FIG. 24 is a side view of a lockdown mechanism according to the present invention; 
     FIG. 25 is a horizontal cross sectional view of the lockdown mechanism of FIG. 24 taken along line  25 — 25  in FIG. 24; 
     FIG. 26 is a vertical cross sectional view of the lockdown mechanism of FIG. 24 taken along line  26 — 26  in FIG. 24; 
     FIG. 27 is a side view of the container guide of FIG. 6 illustrating the container being loaded; 
     FIG. 28 is a side view of the container guide of FIG. 6 illustrating the operation of the container guide; 
     FIG. 29 is a side view of the container guide of FIG. 6 illustrating the loaded position of the container; 
     FIG. 30 is a vertical cross sectional view of the container guide of FIG. 16 taken along line  30 — 30  in FIG. 29; 
     FIG. 31 is a vertical, transverse cross sectional view illustrating the container in a lockdown position; 
     FIG. 32 is an exploded perspective view of an off-load foot according to the present invention; 
     FIG. 33 is a rear view of the off-load foot of FIG. 32; 
     FIG. 34 is a vertical cross sectional view of the off-load foot of FIG. 32; 
     FIG. 35 is a side view illustrating the trailer loading operation; 
     FIG. 36 is a side view illustrating a subsequent step in the trailer loading operation; 
     FIG. 37 is a side view illustrating a further subsequent step in the trailer loading operation; 
     FIG. 38 is a side view illustrating another subsequent step in the trailer loading operation; 
     FIG. 39 is a side view illustrating still another subsequent step in the trailer loading operation; 
     FIG. 40 is a side view illustrating a trailer loaded with two twenty foot containers; 
     FIG. 41 is a side view illustrating the trailer off-loading operation; 
     FIG. 42 is a side view illustrating a subsequent step in the trailer off-loading operation; 
     FIG. 43 is a side view illustrating an alternate trailer off-loading operation utilizing inversion pulleys shown in FIGS. 45 and 46; 
     FIG. 44 is a side view illustrating the trailer off-loading operation for a forty foot container; 
     FIG. 45 is a fragmentary side view illustrating the operation of an off-load inversion pulley according to the present invention; 
     FIG. 46 is a vertical cross section of the inversion pulley of FIG. 45 taken along line  46 — 46  in FIG. 45; 
     FIG. 47 is an exploded perspective view of a bottom wheel assembly according to the present invention, an intermediate lockdown mechanism according to the present invention, and the lockdown mechanism of FIG. 24; 
     FIG. 48 is a perspective view of a front lockdown mechanism according to the present invention; 
     FIG. 49 is a side view of the wheel assembly of FIG.  47  and the front lockdown mechanism of FIG. 48; 
     FIG. 50 is a side view of the wheel assembly of FIG.  47  and the intermediate lockdown mechanism of FIG. 47; 
     FIG. 51 is a vertical cross sectional view of the wheel assembly of FIG.  47  and the front lockdown mechanism of FIG. 48 taken along line  51 — 51  in FIG. 49; 
     FIG. 52 is a vertical cross sectional view of the wheel assembly of FIG.  47  and the intermediate lockdown mechanism of FIG. 47 taken along line  52 — 52  in FIG. 50; 
     FIG. 53 is an exploded perspective view of a pivoting container foot according to the present invention; 
     FIG. 54 is a side view of the pivoting container foot of FIG. 53 attached to an ISO container corner fitting; 
     FIG. 55 is a rear view, in partial cross section, of the pivoting container foot of FIG. 53 taken from a perspective of line  55 — 55  in FIG. 54; 
     FIG. 56 is a perspective view of a trailer according to the present invention including lockdown brackets and container foot receiving slots according to the present invention; 
     FIG. 57 is a fragmentary top view of a back end of the trailer and a front end of the container illustrating a method for loading the container; 
     FIG. 58 is a side view of the illustration in FIG. 57; 
     FIG. 59 is a fragmentary side view illustrating a subsequent step in the method for loading the container; 
     FIG. 60 is a side view illustrating a further subsequent step in the method for loading the container; 
     FIG. 61 is a side view illustrating a still further subsequent step in the method for loading the container; 
     FIG. 62 is a side view illustrating another subsequent step in the method for loading the container; 
     FIG. 63 is a side view illustrating a method for loading a second container behind the first container; 
     FIG. 64 is a side view illustrating a subsequent step in the method for loading the second container; 
     FIG. 65 is a fragmentary side view illustrating a further subsequent step in the method for loading the second container; 
     FIG. 66 is a side view illustrating a trailer loaded with two twenty foot ISO containers; 
     FIG. 67 is side view illustrating a step in a method for unloading containers; and 
     FIG. 68 is a side view illustrating a trailer loaded with a forty foot ISO container. 
    
    
     DETAILED DESCRIPTION 
     Introduction 
     Referring to the drawings in greater detail, the trailer  50  shown in FIG. 1 includes a winch assembly  100  for loading an ISO container  52  onto the deck  54  of the trailer. Wheel mechanisms  200  are attached to at least the lower front corners  56 ,  57  of the container  52  allowing the trailer to roll under the container. The trailer  50  is also provided with inversion pulleys  300 A,  300 B for off loading the container, and an off-load foot  350  (FIG. 32) is provided for connection to the rear  58  of the container to aide in off loading. A cable guide  400  and a container guide  420  are provided to align the container during loading, and a lockdown mechanism  500  (FIG. 24) is provided to hold the container in place on the trailer. 
     FIG. 47 illustrates a bottom wheel assembly  600  and an intermediate lockdown mechanism  700 . A front lockdown mechanism  750  is shown in FIGS. 48 and 49, and a pivoting container foot  800  is illustrated in FIG.  53 . Utilizing the bottom wheel assembly  600  and the front and intermediate lockdown mechanisms,  700 ,  750  allows the containers to be transported on the trailer  50  with the bottom wheel assemblies  600  and container feet  800  attached to the containers  52 ,  96  (FIG. 39) thereby simplifying the loading and off-loading process. 
     Trailer and Container 
     Referring to FIGS. 1 and 2, the standard components of the trailer  50  will be described to the extent necessary for an understanding of the inventive features disclosed herein. The trailer includes a substantial flat deck  54  having a length extending between a front end  60  and a back end  62 . The deck is substantially flat in that it has a small camber or arc from front  60  to back  62 . The trailer also has a width extending between a first side  64  and a second side  66 . Each side of the trailer has a side flange  68 ,  70  with an outer face  72  and a plurality of stake holes  73 . The trailer also has a plurality of wheels  74  rotatably coupled with the deck  54  to support and transport the deck. The trailer also includes a hitch assembly  76  (FIG. 36) for connection to a towing vehicle  78  (FIG.  36 ). The hitch assembly is positioned adjacent to the front end of the deck, and the wheels are movable relative to the deck as taught in U.S. Pat. No. 5,211,413 and U.S. Pat. No. 5,013,056. A control mechanism  80 ,  82  operates to selectively control the functions of the trailer with the trailer control  80  raising and lowering the back end  62  of the trailer and the winch assembly control  82  (FIG. 7) for selectively activating the winch assembly  100 . The winch assembly control  82  also includes a remote control  81  on a cable  83  that is long enough to extend to the back end  62  of the trailer  50 . The trailer control  80 , also includes a remote control (not shown) on a cable that is long enough to extend to the back of the trailer which is designed for operator safety. 
     The container  52  is an ISO container having opposed lower front corners  56 ,  57  and opposed lower rear corners  84 ,  86 . Each corner is provided with a corner fitting  88 , shown schematically in some drawings, having a slot shaped opening  90  with rounded ends on each of the three exposed faces  92 . The container  52  is approximately twenty feet in length, and forty foot containers  94  (FIG. 44) are also provided. Thus, each ISO container has four lower corners with corner fittings for the attachment of components to load, off-load, and lockdown the container. 
     Winch Assembly and Operation 
     Referring to FIG. 2, the winch assembly  100  includes a first movable winch apparatus  102  and a second movable winch apparatus  104  operable to apply force to the container  52 . The first and second winches are mounted on a transport assembly  106  that is centrally attached to the trailer near the front of the deck  54 . 
     The two winches  102 ,  104  are adapted for left hand and right hand rotation and are preferably hydraulic. The winches are otherwise substantially identical and will be described with reference to only one winch with identical reference numerals identifying the similar features of the winches. Referring additionally to FIGS. 7 through 13, the winch includes a cable spool  108  and a winch cable  110  which is wound around the cable spool. The winch cable extends from the winch apparatus through four roller guides  112 ,  114 ,  116 ,  118  on the cable side  119  of the winch assembly. The vertical roller guides  112 ,  114  restrict the movement of the cable in the horizontal direction and the horizontal roller guides  116 ,  118  restrict the movement of the cable in the vertical direction. The winch also includes a guide plate  120  having an upturned end  122  for progressively layering the cable as it is wound onto the spool  108 . The plate  120  is hingably connected by a hinge connection  124  relative to the spool and is biased with a spring  126  against the cable. The winch can be released by the winch controls  82 , so that the cable can be withdrawn from the winch and have its free end  128  (FIG. 16) attached to a desired component. The winch is activated to retract the cable  110  in a pulling direction, indicated by arrow  130 , toward the winch and wind it on the spool  108 . 
     The transport assembly  106  includes a guide shell  132 , a first extendable winch arm  134 , a second extendable winch arm  136 , and an actuating member  138 . The guide shell is rectangular, preferably substantially square, in cross section and is fixedly mounted on the trailer  50  with a mounting assembly  140  in a central location across the width of the trailer and adjacent to the front  60  of the deck  54  and the front of the trailer  50 . A first end  142  of the guide shell includes a large stop  144  attached to the inner surface  146  of the guide shell with conventional fasteners  148 . Preferably, the stop is U-shaped but can extend around the entire inside circumference of the guide shell. The stop  144  operates to center the second arm  136  in the guide shell. The second end  150  of the guide shell is provided with a small stop  152  which is preferably located on all four internal sides of the guide shell  132  and is split into four parts. A feed line opening  154  (FIG. 7) is formed in the cable side  119  of the guide shell to receive hydraulic lines  158  from the control mechanism  82 . A mounting plate  160  is attached to the cable side  119  to hold the lines in place and permit the extendable winch arms  134 ,  136  to slide around the lines  158 . 
     The first extendable arm  134  is also substantially square in cross section and is smaller than the guide shell, so that it is slidably received inside the guide shell. The first arm also has a stop  162  positioned on the outer surface  164  for engaging the small stop  152  of the guide shell thereby limiting the extension of the first arm  134 . The stop is preferably bifurcated into two parts which are placed on the opposite sides of the first arm and extend across substantially the entire height of the first arm. The first winch  102  is fixedly attached inside the first arm adjacent to the outer end  166  of the first arm. The outer end  166  is adjacent the side  64  of the trailer. A cable opening  168  is formed in the cable side  119  through which the cable  110  extends. The roller guides  112 - 118  surround the opening and are fixedly mounted to the cable side  119  of the first arm  134 . The cable side  119  of the first arm also includes a hydraulic line slot  172  through which the hydraulic lines  158  extend. The slot  172  is of sufficient length to allow the arm to fully extend and fully retract without the ends of the slot contacting the hydraulic lines. The inner end  174  of the first arm is opposite the outer end  166  and has a spacer  176  on the upper and lower outer surfaces. The spacer  176  is preferably bifurcated into two parts which extend across substantially the entire width of the first arm. The spacer  176 , in cooperation with the stop  162 , slides against the inner surface  146  of the guide shell to center the first arm inside the guide shell. 
     The second extendable arm  136  has features substantially identical to the first extendable arm which are identified by identical reference numerals. The second arm is substantially square in cross section and is smaller than the first arm, so that the second arm is slidably received inside the first arm. The first arm, second arm, and guide shell are all parallel. The second arm has a bifurcated stop  178  on the sides of the arm and a bifurcated spacer  180  (FIG. 8) adjacent to the inner end  182  of the second arm. The bifurcated stop  178  contacts the large stop  144  to limit extension of the second arm  136 . The bifurcated spacer  180  engages the inner surface  184  of the first arm, and the large stop  144  of the guide shell engages the outer surface  186  of the second arm to center the second arm within the guide shell and within the first arm while allowing the second arm to slide relative thereto. The outer end  166  of the second arm is adjacent the other side  66  of the trailer. 
     The actuating member  138  preferably comprises a hydraulic cylinder. The hydraulic cylinder comprises an elongated piston  188  and an elongated cylinder housing  190  in which the piston is slidably received. The cylinder is housed inside of the first and second arms  134 ,  136  with the piston being attached to the lower portion of the inner surface  184  of the first arm with a fixed connection  192 . The cylinder housing  190  is attached to the inner surface  194  of the second arm  136  with a fixed connection  196 . 
     In operation, the winch control  82  is operated to extend the arms  134 ,  136  and attached winches  102 ,  104  in opposite directions away from the center of the trailer and away from each other until the winches extend beyond the respective sides  64 ,  66  of the deck  54 . Thus, when a winch is moved, it is always moved away from one of the sides and preferably in a direction parallel to the width of the trailer. 
     Referring to FIGS. 38-40, in loading two twenty foot containers the winches are moved apart and the winch cables are first connected to the opposed front corners  56 ,  57  of the front container  52  and the winches are activated to pull the front container substantially all the way forward on the deck  54 . The free ends of the cables are then removed from the opposed front corners  56 ,  57  of the front container  52  and are attached to the opposed front corners of the rear container  96 . The winches are then activated again to pull the trailer under the rear container  96 . The extendable winches allow the cables to extend on either side of the front container, so that the front container does not interfere with loading of the rear container  96 . After the containers are loaded, the winch arms are retracted toward the center of the trailer, so that the winches are between the sides of the trailer. 
     Wheel Assembly and Operation 
     Referring to FIGS. 14 and 15, the wheel assembly  200  comprises a wheel frame  202 , an attachment assembly  204 , and a wheel  206 . The wheel is rotatably mounted in the wheel frame  202 , and the attachment assembly  204  attaches the wheel frame  202  to the corner fitting  88  of the container  52 . 
     The wheel frame  202  comprises opposed vertical side walls  208 ,  210  joined by support rods  212 ,  214 , a jack plate  216 , and a rear plate  218 . The opposed side walls are preferably parallel and have outward protrusions  220 ,  222  through which the front support rod  212  extends. The second support rod  214  is generally centrally located in the side walls and is positioned to center a jack  298  (FIG. 17) over the wheel  206 . The jack plate  216  is positioned adjacent to the top ends of the side walls and is preferably oriented in a horizontal plane. The rear plate  218  is positioned adjacent to the top ends of the side walls at the rear of the side walls and it is preferably oriented in a vertical plane. The side walls  208 ,  210  also include slide tabs  224 ,  226  adjacent to the rear and bottom ends of the side walls. The slide tabs are generally rectangular and extend into the space between the two side walls. Preferably, the slide tabs  224 ,  226  are elongated in a vertical plane. 
     The wheel  206  which is preferably made of a hard metal, is rotatably and slidably mounted between the two side walls  208 ,  210  by a wheel shaft  228  extending through lock slots  230 ,  232  in the opposite side walls. The shaft  228  is secured with conventional fasteners  234  and washers  235  at each end of the shaft. A pair of lock blocks  236 ,  238  each have an aperture  240 ,  242  through which the shaft  228  extends. The lock blocks slide axially on the shaft, and the washers are sized to prevent the lock blocks from coming off the shaft. The lock blocks are preferably positioned outside of the side walls and are free to pivot around and slide on the shaft between the side walls and the washers. The lock blocks  236 ,  238  also include outer grasping portions  244 ,  246  which are sized so that they will not pass through the lock slots  230 ,  232 . The lock blocks further include inner portions  248 ,  250  sized to fit into the lock slots with minimal clearance for hand insertion and removal. The inner portions together with the shaft fill the lock slots. 
     The attachment assembly  204  includes a fastener  252 , an attachment block  254 , and a locking member  256 . The fastener comprises a threaded end  258  for threaded engagement with a nut  260  and an elongated head  262  sized to fit through the opening  91  in the corner fitting  88  when the fastener is held in the orientation shown. When the orientation of the fastener is rotated 90° it cannot pass through the opening  91  as illustrated in FIG. 25. A pin  265  is also preferably used to hold the fastener in place while the attachment block is being connected to the corner fitting  88 . The pin extends through small openings  267 ,  269  in the attachment block and fastener respectively. 
     Referring additionally to FIG. 31, the attachment block  254  comprises an aperture  264  for receiving the fastener  252  and a recess  266  on its outer side  268  to receive the nut  260 . The inner side  270  has a fastener head engagement collar  272  which keeps the fastener head from rotating during tightening. The collar  272  is generally U-shaped and includes upper and lower legs  274 ,  276  having flat inner faces  278 ,  280  for engaging the fastener head  262  and curved outer faces  282 ,  284  which fit between the fastener head and the ends of the opening  91  to fill the opening  91  whereby the attachment assembly  204  is substantially fixed from moving relative to the ISO container  52 . Each leg also includes a chamfer  279 ,  281  for easier engagement with the fastener head  262 . 
     The attachment block  254  also includes opposed outward facing slide channels  286 ,  288  which form a slide connection with the slide tabs  224 ,  226  allowing the wheel frame to slide up and down relative to the attachment block  254 . The wheel frame  202  is held in place relative to the attachment block by the locking member  256  which extends through a pair of apertures  290  in the side walls and through a cylindrical hole  292  in an upper portion of the attachment block. The slide tabs and apertures  290  are all preferably aligned in the same vertical plane. A safety pin  296  is provided to prevent the locking member  256  from being inadvertently removed. 
     In operation and referring additionally to FIGS. 16-20, the attachment block  254  is fastened to the corner fitting  88  with the fastener  252 , and the slide tabs  224 ,  226  are slid into the slide channels  286 ,  288 . The locking member  256  is inserted through the pair of apertures  290  and the opening  292  to lock the wheel frame in place relative to both the attachment assembly and the container. The rear plate  218  abuts against the container  52  to stabilize the wheel assembly. At this point, the wheel is in the lowered position as shown in FIG. 17. A jack  298  is inserted into a jack receiving area  291  between the wheel  206  and the jack plate  216 . The jack  298  includes a curved bottom  293  to engage the wheel  206  and a flat top  295  to engage the flat jack plate  216 . The jack  298 , which is preferably hydraulic, is then actuated to press the jack plate upwardly relative to the wheel to lift the wheel frame and container as illustrated in FIG.  19 . The lock blocks are then manipulated to insert the inner portions  248  into the lock slots  230 ,  232  thereby locking the wheel in the raised position. The top  295  of the jack  298  is then retracted and the jack removed. Thus, a single jack can be used to place a container on wheels. 
     Using the wheel assembly  200  in the loading and unloading operation is described with reference to FIGS. 35-40. Wheel assemblies are attached to the opposed front corners  56 ,  57  of the container  52  and the winches  102 ,  104  are activated to initially draw the trailer underneath the front of the container while the container remains substantially stationary. When the container is almost entirely on the trailer, i.e., the back end of the trailer is within three or four feet of the rear  58  of the container, the trailer controls  80  are then operated to raise the back end  62  of the trailer  50 , and wheel assemblies are attached to the opposed rear corners  84 ,  86  of the container. The back end of the trailer is then lowered again, and the winches are activated to pull the first container into place on the deck. The wheel frames are then removed from the attachment assemblies. The same procedure is repeated with the second container  96  or a forty foot container  94  with the exception that wheel assemblies are preferably not attached to the rear of the second container or of the forty foot container, so that the trailer is pulled underneath the container to load the container onto the trailer. If space permits, the wheel frames are left attached to the opposed front corners of the second container, and space permitting, preferably all of the attachment assemblies  204  are left on the containers. 
     In off loading the containers, the wheel frames are quickly reattached as described above to the attachment assemblies for off loading. After the containers are off-loaded, the attachment assemblies can then be removed from the corners of the ISO containers. As an alternative to the above loading operation, wheel assemblies could be attached to all four corners of the containers, and instead of the trailer being backed underneath the containers, the containers could be pulled up onto the trailer or some combination thereof. 
     Inversion Members and Operation 
     Referring to FIGS. 43-46, the trailer  50  is preferably provided with off-load pulleys  300  which act as inversion members to change the pulling direction  130  (FIG. 7) of the winches. The off-load pulleys  300  are operatively coupled with the container by a container attachment  302  and are rotatably mounted to the trailer with a trailer attachment  304 . 
     The off-load pulleys  300  preferably comprise cylindrical disks. The perimeters  306  of the disks preferably define cable receiving grooves  308 . Preferably, a first set of two pulleys  300 A are positioned near to the front  60  of the deck  54 , and a second set of two pulleys  300 B are positioned near the center of the deck  54 . Each pulley of the first set of pulleys  300 A is positioned on opposite sides of the trailer at the same desired point along the length of the trailer approximately four feet from the front of the deck. The front pulleys are used to off-load a forty foot container as shown in FIG. 44 or off-load a front container. Each pulley of the second set of pulleys  300 B are positioned on opposite sides of the trailer at the same desired point approximately four feet rearward from the center of the deck. The second set of pulleys can be used to off-load any container but are preferably used to off-load a rear twenty foot container. 
     For sake of brevity the off-load pulleys will be described with reference to only one pulley. The container attachment  302  preferably comprises one of the container guides  420  which will be discussed in detail below. The container attachment attaches the free end  128  of the cable  110  to the front corners  56 ,  57  of the container  52 . 
     The trailer attachment  304  includes a shaft receptacle  310  welded to the side flange  68  of the deck  54 . The shaft receptacle  310  receives a shaft  312  into a center aperture  320  and is locked in the shaft receptacle by a lock pin  314 . The shaft  312  is fixed from rotation by the lock pin  314 , so that the pulley rotates on a bushing  316  around the shaft  312 . The pulley is attached to the shaft with a conventional fastener/washer assembly  318 . Thus, the pulleys can be removed for transport or left attached in the shaft receptacle  310 . 
     In operation, to unload a forty foot container  94 , the winch cables  110  are wrapped around the first set of pulleys  300 A and connected to the container attachment  302  at each front corner of the container as illustrated in FIG.  44 . The winch is activated to pull the container rearwardly until the rear end of the container hangs far enough over the back end of the trailer, so that the rear of the container will not move while the tractor is driven from underneath the container. 
     To unload two twenty foot containers, the winch cables  110  are wrapped around the second set of pulleys  300 B and the free ends  128  of the cables are attached to the front corners of the rear container  96  as shown in FIG.  43 . The cables are held in the cable grooves  308  as the winches are activated to pull the container  96  rearwardly until it overhangs the back end of the trailer enough to be off-loaded. The cables are then disconnected from the rear container  96  wrapped around the first set of pulleys  300 A and attached to the front corners of the front container  52 . The winches are again activated pulling the container rearwardly. When the front of the container reaches the first set of pulleys  300 A the winch cables are removed from the first set of pulleys and wrapped around the second set of pulleys to continue pulling the front container rearwardly until its rear end hangs over the back end of the trailer. If the winch cables have sufficient length they can be wrapped around the second set of pulleys initially. Thus, the pulleys operate to alter the pulling direction of the winches and preferably substantially invert the pulling direction of the winches, so that the power of the winches can be used to both load and off-load containers. 
     Off-Load Foot and Operation 
     Referring to FIGS. 32-34, the off-load foot  350  includes an attachment assembly  352  for connection to a rear corner fitting of a container and a downwardly extending leg  354  connected to the attachment assembly. The downwardly extending leg  354  engages the ground surface  85  (FIG. 42) to aid in off loading containers. 
     The attachment assembly  352  comprises a fastener  356  for insertion into the opening  90  of the corner fitting  88  and an attachment block  358  having a central aperture  360  receiving the fastener therethrough. The block also includes a generally U-shaped fastener head engagement collar  362  which includes upper and lower legs  364 ,  366  for engaging the fastener head  368  and which fit between the fastener head and the ends of the opening  90  to fill the opening  90  whereby the attachment assembly  352  is substantially fixed from moving relative to the ISO container  52 . The fastener  356 , block  358 , and collar  362  are substantially similar to and operate in substantially the same manner as those components provided on the attachment block of the wheel assembly. 
     The attachment block includes a pin hole  369  for receiving a pin  370  which extends through the pin hole and into an opening  372  in the fastener to hold the fastener and attachment block in place while the collar  374  is threaded onto a threaded end  376  of the fastener utilizing wrench holes  378  spaced around the circumference of the collar  374 . To hold the tightened collar in place, a lock pin  390 , preferably provided by transferring pin  370 , is inserted through one of four collar lock slots  392  formed around the circumference of the collar and extends into an opening  394  in the threaded end  376  of the fastener  356 . 
     The downwardly extending leg  354  includes an aperture  380  receiving the fastener therethrough and a cylindrical torsion resistance member  382  having a central aperture  384  concentric with the aperture  380  of the downwardly extending leg  354 . The downwardly extending leg has an upper end  386  and a ground end  388  with the torsion resistance member  382  being attached adjacent to the upper end  386 . The downwardly extending leg has a base  396  attached thereto having elongated upturned edges  397 ,  398 . The upturned edges preferably extend across the entire length of the downwardly extending leg and allow the off-load foot to rock on top of the ground surface without damaging the ground surface. 
     In operation and referring to FIGS. 41 and 42, an off-load foot  350  is attached to each rear corner of the container, and the back end of the trailer is lowered until the base  396  contacts the ground surface  85  and lifts the rear end of the container off the back end of the trailer. The trailer is pulled forward out from underneath the container until there is approximately four feet of the container over hanging the back end of the trailer. This is a sufficient distance for the rear bottom edge of the container to securely engage the ground surface  85  without sliding. Preferably, the back end of the trailer is lifted again, and the off-load feet are removed. The trailer is then lowered and pulled forward the rest of the way out from underneath the container. 
     The off-load foot can also be utilized during the last several feet of pulling a trailer with a cambered/arced deck under, for example, a 40 foot container, to keep from dragging the container bottom on the trailer. The rear of the trailer is lifted, and an off-load foot is attached to each rear corner of the container. The rear of the trailer is then lowered until the ground end of the off-load foot securely contacts the ground surface and lifts the rear of the container off the camber of the trailer. The trailer can then be pulled under the container to a loaded position. 
     Cable Guides 
     Referring to FIGS. 3 through 6, the cable guide  400  is provided in combination with the trailer and includes a stake-hole post  402  and a guide portion  404  connected to a top end  406  of the stake-hole post. The stake-hole post is elongated and has a configuration and size, preferably two rods welded together, to fit snugly in a stake hole  73 . The bottom end  412  of the stake-hole post is inserted into the stake hole. The guide portion  404  preferably comprises a cylindrical disk having a cable groove  408  formed in its perimeter. The disk is preferably rotatably secured to the stake-hole post with a fastener/washer assembly  410 . 
     In operation, the cable guide  400  is used to align a container  53  that is out of alignment with the deck  54 . The cable guide is capable of aligning the container  53  if the container is oriented at an angle with the deck or positioned to one side of the deck as shown in FIG.  3 . The cable guide  400  is inserted into a desired stake hole along the length of the trailer. The cable  110  is positioned in the cable groove  408 . The winches are activated pulling the container toward the deck and aligning the container with the deck. The cable guide can be moved from one stake hole to another to better achieve alignment, and cable guides can be used on both sides of the trailer. As the cable is pulled past the cable guide, the guide portion  404  rotates, so that the cable moves smoothly past the cable guide. The cable guide operates to alter the pulling direction of the winches, as desired, enough to align the container with the trailer. 
     Container Guides 
     Two embodiments of the container guides  420 A,  420 B are shown in FIGS. 14 and 16. The embodiment shown in FIG. 14 will be discussed first. The container guide  420 A comprises a container guide body  422 , an attachment mechanism  424  for attaching the container guide body to the container, a winch cable attachment assembly  426 , and a elongated downwardly extending member  428 . 
     The container guide body  422  is preferably a flat plate having a first aperture  430  for attachment to the cable and a second guide pin aperture  432  to receive the downwardly extending member  428 . The apertures are approximately the same size, so that the cable can be attached to the rearward second aperture, or an added third aperture, for off loading containers with the inversion pulleys  300 . The container guide body also has an attachment mechanism leg  434  connecting the container guide body to the attachment mechanism  424 . 
     The attachment mechanism  424  comprises a twist lock tab  436  integral to the attachment leg  434  for connection to the corner fitting of the container. When the attachment leg  434  is vertically oriented as shown in phantom lines, it fits into the opening  90  of the corner fitting. The container body and attachment tab have been rotated ninety degrees to lock the attachment tab in the corner fitting. The twist lock tab  436  allows the container guide body  422  to pivot relative to the container. The degree of pivot is controlled by the pulling angle of the cable. 
     The winch cable attachment assembly  426  comprises a U-shaped cable termination  438  attached to the free end of the winch cable  110 . Each leg  440 ,  442  comprises an aperture  444 ,  446  for alignment with the preferably circular aperture  430  in the container body, and the legs are spaced far enough apart to receive the container body therebetween. A lock member  448 , preferably a cylindrical pin, extends through the apertures  430 ,  444 ,  446  to connect the free end  128  of the cable to the container guide body  422  and a safety pin  450  (FIG. 16) is inserted through an opening  452  in the bottom of the lock cylinder  448  to prevent unintentional removal. 
     The downwardly extending member  428  preferably comprises a cylindrical pin extending through the preferably circular aperture  432  in the container guide body. The member  428  includes an enlarged head  454  which prevents it from falling through the aperture  432 . The downwardly extending member has a length sufficient to extend below a top surface of the deck, and the container guide body extends away from the container a sufficient distance for the downwardly extending member to be positioned beyond the side of the trailer. 
     In operation and with reference to FIGS. 21-23, the container guide body is connected to the corner fitting and the winch cable is connected to the container guide body. The winches are activated to start pulling the trailer underneath the container and when the container is far enough on to the deck  54 , the elongated member  428  is dropped into the aperture  432  to hold the container in alignment with the deck  54 . If the container is being pulled all the way to the front of the deck, a container guide is preferably attached to both the front and rear corners of the container. As the container is moved relative to the deck  54 , the elongated member  428  contacts the sides  64 ,  66  of the deck. The elongated member  428 , slides against the sides of the deck and preferably rotates in the aperture  432  to roll against the sides of the deck. 
     The container guide can be used in conjunction with the cable guides by placing the container guide on the corners and pulling the container towards the trailer until the elongated member  428  contacts the side of the container. The container guide then keeps the container from moving past the aligned position. This is particularly effective for correcting angular misalignments between the trailer and container. 
     Referring to FIGS. 16 and 30, the second embodiment of the container guide  420 B includes a container guide body  456 , an attachment mechanism  458  for attaching the container guide body to the container, a winch cable attachment assembly  460 , and a elongated downwardly extending member  462 . The winch cable attachment assembly  460  is substantially identical to the winch cable attachment assembly  426  of the prior embodiment and will not be described again. 
     The container guide body includes two legs  464 ,  466  spaced at an angle of approximately 90°. The first leg  464  comprises a short leg having an aperture  468  for attachment to the winch cable. The second leg  466  comprises a long leg which operates as the elongated member  462  and includes an aperture  470  for attachment to the winch cable  110 . An extension sleeve  484  is attached to an inner side  488  (FIG. 30) of the body  456 , so that the body is positioned beyond the side of the trailer. The edges of the body  456  have a chamfer  486  (FIG. 30) for engaging the side of the trailer. The container guide body  456  also includes a fastener aperture  472  at its pivot corner  474 , so that the body  456  is attachable in two configurations. In one, the elongated member is substantially parallel to the deck and in the other, the elongated member extends below the top surface of the deck to engage the sides of the deck. 
     The attachment mechanism comprises a fastener  476 , attachment block  478 , collar  480 , and safety pin  482  which are substantially identical to the similar components described in conjunction with the off-load foot. Thus, these components will not be described again. 
     In operation and referring to FIGS. 27-30, the cable is first attached to the aperture  470  in the long leg  466 , and the trailer is pulled underneath the container until the front of the container is elevated enough over the ground surface  85 , so that the elongated member  462  can be extended downwardly without contacting the ground surface. The cable is then removed from the long leg aperture  470 ; the container body  456  is pivoted on the fastener around the pivot corner  474  until the long leg  466  extends downwardly, and the cable is attached to the short leg aperture  468  to continue pulling the trailer underneath the container. The elongated member  462  contacts the sides of the trailer and operates to align the container and keep the container in alignment during loading. 
     Lockdown Mechanism 
     Referring to FIGS. 23-26, the lockdown mechanism  500  includes an attachment member  502  for attaching to the container, a pivotal securement member  504  for attaching to the deck, and an extension member  506 . The attachment member  502  preferably comprises the container guide body  422  of the first embodiment of the container guide  420 A incorporating a twist lock tab  507  for quick connection and disconnection to the corner fitting. The attachment member  502  also includes an extension member aperture  508  and a cable connection aperture  510 . 
     The pivotal securement member  504  comprises a pair of generally rectangular tabs  512 ,  514  on opposite sides of the securement member. The securement members are preferably attached to the first and second outer faces  72  of each side flange  68 ,  70  so that there are a total of six securement members in locations corresponding to the four corners of a loaded front container  52  and to the two front corners of a rear container  96 . The tabs are received in weldment brackets  516 ,  518  which define openings  522  between the brackets and the side flange  68  allowing the rectangular tabs  512 ,  514  to be pivoted therein between a lockdown position (FIG. 24) and a disconnected position (FIG.  23 ). The rectangular tabs  512 ,  514  also include a pivot chamfer  520  which provides further freedom in pivoting the tabs inside the openings  522 . The pivotal securement member also includes an extension member opening  524  near its movable end  526 . 
     The extension member  506  is preferably provided by the downwardly extending member  428  of the first embodiment of the container guide  420 A. The extension member  506  is preferably cylindrical having an enlarged cylindrical head  528  to prevent it from passing through the extension member aperture  508 . The lower end  530  of the extension member has an opening  532  to receive a lock pin  534  which prevents the securement member and the extension member from inadvertently disconnecting. Once connected, the extension member  506  is substantially perpendicular to the securement and attachment members which are substantially parallel to each other. 
     In operation, the container is moved to the location shown in FIG.  23  and the extension member  506  is lifted partially out of the extension aperture  508 . The securement member  504  is pivoted upwardly toward the extension member until it is substantially parallel with the attachment member  502 . The extension member is then inserted through the aperture  524  in the securement member  504 , and the lock pin  534  is inserted through the opening  532  in the extension member. This lockdown mechanism replaces the conventional lockdown mechanism  75  shown in FIG. 32 which is still preferably used at the back end  62  of the deck. The improved lockdown mechanism  500  is easier to attach and remove and thus is preferably used at all container corners on both sides of the trailer. Because at least one, but preferably both, of the attachment member and the securement member extend far enough so that the apertures  524 ,  508  are positioned beyond the side flange, the extension member is positioned beyond the side of the trailer, and the lockdown mechanism is accessible from beside the deck. 
     The features of the disclosed self-contained trailer significantly simplify the loading and off-loading operations. The features allow a single person to load and off-load containers. Further, these features allow containers to be more easily loaded from angled and misaligned orientations. 
     Bottom Wheel Assembly and Operation 
     Referring to FIGS. 47,  51 , and  52 , the bottom wheel assembly  600  includes a mounting bracket  602 , and a plurality of non-castering wheels  604 ,  606 ,  608  rotatably mounted on a wheel axle  610 . The mounting bracket  602  is mounted in the bottom hole  612  of a rear ISO container corner fitting  84  (56-front corner fitting). The mounting bracket  602  and wheels  604 - 608  are positioned below the container and stay within the extremities of the container  52  when attached no matter which direction the container is being moved. 
     The mounting bracket  602  includes a substantially rigid shoulder portion  614  and a substantially rigid attachment portion  616  formed by two opposed components  618 ,  620 . The two opposed components, which have substantially the same outlines, include an inside component  618  and an outside component  620  spaced apart from the inside component. To achieve the spacing, each of the components include curved ends  622 . The opposed pairs of curved ends are fixedly connected by weld connections  624 . 
     The shoulder portion  614  is substantially rectangular with upwardly extending and rounded tabs  626  which define an upper pair of aligned lock pin openings  628 ,  630 . The inside lock pin opening  628  is substantially circular, and the outside lock pin opening  630  is also substantially circular and includes opposed rectangular openings  632 . The attachment portion  616  is generally rectangular with generally triangular tabs  634  extending downwardly. The attachment portion  616  defines a lower pair of aligned wheel axle openings  636 ,  638 . The inside wheel axle opening  636  is substantially circular, and the outside wheel axle opening  638  is also substantially circular and includes a downwardly extending rectangular key way  640 . 
     The shoulder portion  614  is sized to inhibit the mounting bracket  602  from sliding in the bottom hole  612  and to properly position the lock pin openings  628 ,  630  in the front ISO container corner fitting  56  (84-rear corner fitting), so that the lock pin openings  628 ,  630  are aligned with the base of the side hole  642  of the ISO container corner fitting  56 . A lock pin  644  is inserted through the side hole  642  of the ISO container corner fitting  56  and through the lock pin openings  628 ,  630 . The lock pin openings are positioned to inhibit relative vertical movement between the mounting bracket  602  and the corner fitting  56 . The lock pin  644  includes an inward key pin  646  which passes through the rectangular openings  632  in the outside lock pin opening  630 . When the lock pin  644  is rotated, the inward key pin  646  locks the lock pin in position thereby mounting the mounting bracket  602  onto the corner fitting  56 . The inward key pin is positioned along the length of the lock pin so that the inner end  648  of the lock pin  644  cannot be removed from the inside lock pin opening  628  without aligning the inside key pin  646  with the rectangular openings  632  in the outside lock pin opening  630 . In one embodiment the lock pin  644  also includes an outward key pin (not shown) positioned adjacent to the handle  650  of the lock pin  644 . 
     The wheel axle  610  is cylindrical and extends through the wheel axle openings  636 ,  638 . The central wheel  606  is rotatably held on the wheel axle  610  and positioned between the inside and outside components  618 ,  620  of the mounting bracket  602 . The inside wheel  608  is rotatably mounted on the wheel axle and is positioned outside of the mounting bracket and adjacent the inside component  618 . The inside wheel  608  is held on the wheel axle by an inside wheel attachment pin  652  which engages an inside wheel washer  654  also mounted on the wheel axle next to and outside of the inside wheel  608 . 
     The outside wheel  604  is rotatably mounted on a wheel axle  610  and is positioned outside of the mounting bracket and adjacent the outside component  620 . The outside wheel  604  is held on the wheel axle by an outside wheel axle attachment pin  656  which engages an outside wheel washer  658 . The outside wheel washer  658  is mounted on the wheel axle next to and outside of the outside wheel  604 . 
     The wheel axle also includes an axle key  660 . The axle key is positioned along the length of the wheel axle, so that it extends into the key way  640  formed in the outside wheel axle opening  638 . Thus, the axle key  660  substantially prevents the wheel axle from rotating. The wheel axle also includes a threaded lockdown extension  662  and at least one but preferably a pair of rounded lockdown extensions  664  extending from opposite ends of the wheel axle. For purposes of definition, the lockdown extensions  662 ,  664  are not included in the bottom wheel assembly  600 . The threaded lockdown extension  662  cooperates with and forms a part of the intermediate lockdown mechanism  700  as described below. Thus, the threaded lockdown extension  662  forms an intermediate lockdown area of the lockdown extension which is attached to the container by the mounting bracket  602 . The rounded lockdown extensions  664  cooperates with and forms a part of the front lockdown mechanism  750  as described below. Thus, the rounded lockdown extensions  664  forms a front lockdown area of the lockdown extension which is also attached to the container by the mounting bracket, so that the lockdown extensions extend from the mounting bracket  602 . 
     In operation and with reference to FIGS. 56 through 59, two bottom wheel assemblies  600  are attached to the lower front corner fittings  56 ,  57  of the container  52  by lifting the container with the back end  62  of the trailer  50 . Specifically, chains  668  are hooked into chain hook holes  669 , “gotchas” located in the approach plate at the rear of the trailer and attached to the front corner fittings, and the back end of the trailer is raised lifting the container off the ground. Blocks  670  are positioned underneath the container and the container is lowered onto the blocks. With the container supported on the blocks, the chains  668  are removed and the wheel assemblies are attached by inserting the positioning shoulder  614  of each mounting bracket inside the bottom holes  612 . The lock pins  644  are then inserted into the lock pin openings  628 ,  630  mounting the wheel assemblies onto the bottom of the container. The back end  62  of the trailer is then positioned underneath the wheel assemblies and the front of the container is lifted off of the blocks  670 . The blocks are then removed, and the back end  62  of the trailer  50  is lowered to pull the trailer under the container keeping the back end  62  of the trailer off the ground  85 . The wheel assembly and the mounting brackets are sized and positioned so that they are contained within the extremities of the container, and even with the lock pins  644  in place, there is still room for the attachment member  502  of the lockdown mechanism  500  to be held in the side opening  642  of the corner fitting. 
     Referring to FIGS. 60-64, the trailer is then backed under the container until the back end  62  of the trailer is near the rear corner fittings  84 ,  86 . The back end  62  is then lifted and two additional bottom wheel assemblies are attached to the rear corner fittings of the first container  52 . If the second container  96  (FIG. 67) or the forty foot container  94  (FIG. 68) is being loaded, then the container feet  800  are attached to the rear corner fittings. The trailer is then lowered and pulled the rest of the way under the container. The container is then secured with the proper lockdown mechanisms  500 ,  700 ,  750  with the wheel assemblies  600  and container feet  800  still attached. The wheel assemblies  600  and container feet can also be left attached to the containers when the containers are stored. To load and off-load the front container  52  without removing the wheel assemblies from the rear corner fittings  84 ,  86 , wheel chocks (not shown) can be used to keep the container from rolling relative to the ground surface  85 . The remaining details of loading and off-loading the containers are as described both above and below. 
     Intermediate Lockdown Mechanism 
     Referring to FIGS. 47,  50 , and  52 , the intermediate lockdown mechanism  700  includes the threaded lockdown extension  662  of the wheel axle  610  and a lockdown bracket  702 ,  704  having a securement portion  702  and a trailer attachment portion  704 . The trailer attachment portion  704  is attached to the trailer  50 , and the securement portion  702  selectively connects the lockdown extension to the trailer attachment portion. 
     The securement portion  702  includes a threaded lockdown extension connector  706  and a generally triangular lockdown flange  708 . The trailer attachment portion  704  includes a pair of clips  710 ,  712  and a central abutment block  714 . The lockdown flange  708  defines a slotted extension opening  716  near the top corner of the flange  708  receiving the lockdown extension  662  therethrough, and the clips  710 ,  712  are connected to the bottom corners of the flange  708 , so that the clips are spaced apart. Thus, the flange  708  is attached to the trailer attachment portion. The clips are preferably U-shaped having top and bottom legs  718 ,  720  with the top legs  718  extending over the top of the deck, and the bottom legs  720  extending under the deck. Thus, the U-shaped clips engage a side flange  68  of the trailer receiving the side flange  68  between the top and bottom legs  718 ,  720 . 
     The lockdown extension connector  706  comprises a nut which threads onto the lockdown extension  662 . A washer  722  is interposed between the lockdown flange  708  and the connector  706 . The central abutment block  714  is attached to the trailer side flange  68  underneath the flange at an intermediate location between the front end and back end  62  of the trailer  50 . 
     In operation and with reference to FIGS. 50 and 66, the container is positioned on the trailer, so that the lockdown extension  662  is aligned with the abutment block  714 . The clips  710 ,  712  are then slid onto the trailer side flange. The clips are positioned on opposite sides of the central abutment block  714 . Substantially simultaneously, the lockdown extension  662  is inserted into the extension opening  716  of the lockdown flange  708 . The extension connector  706  is threaded onto the lockdown extension  662 . The clips engage the central abutment block to restrict rearward and forward movement of the container, and the clips also restrict vertical movement of the container. Because a substantially identical lockdown mechanism is used on the opposite side of the container, the clips of the two intermediate lockdown mechanisms combine to restrict side to side movement of the container thereby securing the container to the trailer. If the container is a little off center on the trailer, the extension connector  706  can be further rotated to center the container. 
     The intermediate lockdown mechanism is preferably used for the rear corners of the first container and the front corners of the second container. Thus, there are four blocks  714  attached to the trailer side flange  68 . The intermediate lockdown mechanism  700  can also be used in place of the front lockdown mechanism  750 . 
     Front Lockdown Mechanism 
     Referring to FIGS. 48,  49 , and  51 , the front lockdown mechanism  750  includes the rounded lockdown extensions  664  and a lockdown bracket  752 ,  754  having a securement portion  752  and a trailer attachment portion  754 . Again, the trailer attachment portion  754  is attached to the trailer  50 , and the securement portion  752  selectively connects the lockdown extension to the trailer attachment portion  754 . 
     The securement portion includes a pair of spaced apart upper legs  756 ,  758  and a pair of spaced apart lower legs  760 ,  762 . The lower legs  760 ,  762  are attached to the trailer attachment portion  754 . Each upper leg is combined with a lower leg underneath the respective upper leg, and the upper and lower legs are spaced apart to receive the rounded lockdown extensions  664  in the open ended slot therebetween. Thus, the rounded lockdown extension  664  are held between the upper legs  756 ,  758  and the trailer deck  54  as well as between the upper and lower legs. The rounded lockdown extensions  664  extend from opposite sides of the wheel axle  610  beyond the inside and outside wheels  608 ,  604 , and the upper and lower pairs of legs are sufficiently spaced apart to receive the wheels  604 - 608  therebetween. 
     The lower legs  760 ,  762  each include an outwardly extending tip  764  extending away from the front end of the trailer. The outwardly extending tips  764  act to guide the wheels between the pairs of upper and lower legs  756 - 762 . The bottom legs also define aligned chock pin openings  766  for receiving a chock pin  768  therethrough. A cotter pin  770  is attached to the inside end  772  of the chock pin  768  to secure the chock pin  768  in the chock pin, openings  766 . The upper legs reduce in thickness toward their back ends  774 , so that the opening between the upper and lower legs increases in size towards the back ends of the upper legs to held guide the rounded lockdown extensions between the upper and lower legs  756 - 762 . Further, the back ends  774  are rounded to guide the extensions  664 . 
     The trailer attachment portion  754  preferably comprises a stake hole connector having a top plate  776 , a stake hole arm  778 , and a bottom plate  780 . The stake hole arm  778  is attached to the top plate and extends through a stake hole  73  of the trailer deck, and the top plate  776  sets on top of the trailer deck. The stake hole arm  778  extends beyond or at least flush with the stake hole legs  782 . The bottom plate  780  is attached to the stake hole arm  778  with fasteners  784 . The fasteners  784  thread into the stake hole arm  778  until the bottom plate  780  engages the stake hole leg  782  thereby holding the top plate  776  securely on top of the deck. The top plate  776  is generally rectangular with an expanded rear portion  786  which extends under the outwardly extending tips  764  of the lower legs  760 ,  762 . The expanded rear portion  786  also includes a ramp  788  allowing the wheels  604 - 608  to easily roll from the deck to on top of the top plate  776 . 
     In operation and with reference to FIGS. 48,  49 , and  56 , the first container  52  is pulled forward by the winch assembly  100  and the wheels  604 - 608  are pulled up the ramp  788  onto the top plate  776 . The container is pulled further forward until the rounded lockdown extension  664  is positioned between the upper and lower legs  756 - 762  of the securement portion  752 . Because the wheel axle is substantially fixed from rotation by the axle key  660  positioned in the key way  640  (FIG.  51 ), the inward and outward key pins  646 ,  650  are held in a position where they do not interfere with insertion of the rounded lockdown extensions between the upper and lower legs. As the rounded lockdown extensions  664  are pulled forwardly between the upper and lower legs, the upper leg elastically flexes upwardly as illustrated in FIG.  49 . Thus, the rounded lockdown extensions  664  force the upper legs upwardly when the extensions  664  are properly positioned, so that the chock pin  768  can be inserted through the chock pin opening  766  behind the wheels  604 - 608  fixing the chock pin relative to the upper and lower legs. The upper and lower legs restrict vertical, side to side, and forward movement of the container, and the chock pin  768  restricts rearward movement of the container. Thus, the front lockdown mechanism  750  secures the container  52  on the trailer  50 . 
     The forty foot container  49  utilizes two wheel assemblies and two container feet. The first container  52  has four wheel assemblies attached thereto, and like the forty foot container  94 , the second container  96  has two wheel assemblies and two container feet. To accommodate these variations the trailer includes four central abutment blocks  714  and two front lockdown brackets  752 ,  754 . 
     The above described lockdown mechanism  500  also includes a lockdown extension, securement portion, and trailer attachment portion. The attachment member  502  provides the lockdown extension. The securement member  504 , extension member  506 , and lock pin  534  make up the securement portion, and the weldment brackets  516  provide the trailer attachment portion. 
     Container Foot 
     Referring to FIGS. 53-55, the container foot  800  includes a foot mounting bracket  802  which is substantially identical to the wheel assembly mounting bracket  602  and attaches to the container in substantially the same way. Thus, it is possible for the disclosed universal mounting bracket to mount a selected one of the bottom wheel assembly  600 , the lockdown extensions  662 ,  664  and the container foot  800 . 
     The container foot further includes a platform  804  pivotally attached to the foot mounting bracket  802 , by a pivot pin  806 . The platform  804  is substantially rectangular having a large surface area, and a pair of triangular mounts  808  are attached to the top of the platform  804 . The mounts define pivot pin receiving openings  810 . The pivot pin  806  extends through the wheel axle openings  636 ,  638  in the mounting bracket  802  and through the pivot pin receiving openings  810 . The triangular mounts  808  are positioned between the inside and outside components  618 ,  620  of the mounting bracket  802 , and the pivot pin includes a lock key  812  which is positioned between the triangular mounts  808  to hold the pivot pin in position. 
     In operation and with reference to FIGS.  55  and  63 - 66 , when loading a second twenty foot container  96  or a forty foot container  94  onto a trailer  50 , a container foot  800  is attached to each of the rear corner fittings of the container. Specifically, the trailer is backed underneath the second container  96  until the back end  62  of the trailer is near the rear corner fittings, and then the back end  62  of the trailer is lifted to raise the rear corner fittings. The container feet  800  are then connected to the corner fittings, and the trailer back end  62  is lowered until the platform  804  rests on the ground surface. Because the platform pivots relative to the fool mounting bracket  802 , the platform rests parallel to the ground surface  85  thereby distributing the load of the container to minimize or substantially prevent damage to the ground surface. 
     The trailer is then backed further under the container until the mounting brackets are received in container foot receiving slots  814 ,  816  (FIG. 57) defined in the back end of the trailer. To guide the foot mounting brackets  802  into the slots  814 ,  816  each slot includes a widening mouth  818 . The receiving slots are sized to securely hold the foot mounting bracket therein, so that the container foot operates as a lockdown for the container. As with the wheel assemblies, the container foot  800  is positioned within the extremities of the container, so that it can be left attached to the container during transport. 
     Although preferred forms of the invention have been described above, it is to be recognized that such disclosure is by way of illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Modifications to the exemplary embodiments, as herein above set forth, could be readily made by those skilled in the art without departing from the spirit of the appended claims. 
     The inventor(s) hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of their invention as it pertains to any apparatus or method not materially departing from but outside the literal scope of the invention as set out in the following claims.