TECHNICAL FIELD The present invention relates to a trailer for transporting a freight container and its method of use. Preferably, but not exclusively, the container is an ISO certified container. BACKGROUND ART Container handling transport vehicles of various types are known for transporting different types of freight containers on existing public roads. However, these transport vehicles and containers have to abide to government regulations when traveling on such public roads. Accordingly, containers are manufactured with strict design regulations as to size. ISO certified containers are also fabricated with specific attachments whereby to be handled and secured during transport, whether by land, sea or air. Handling equipment is also designed to engage these attachments for secure handling and transportation. The trailer design of the present invention is particularly adapted to handle such ISO certified containers which can be rested directly on a ground surface and difficult to access location. Accordingly, there is no requirement to provide elevated frames to support the container elevated for transfer onto conventional trailers such as described for example in U.S. Patents 5,417,540, 6,155,770, 6,532,398 and others .

Transporters for picking up containers lying on ground and transferring them on a transport vehicle support frame are also known. A most common type are those open top end containers in which refuse from building sites are deposited and later picked up by pulling the container on a pivoted support frame by a winch and cable, the container is then positively engaged for transport to a refuse disposal site. Other vehicles are also known to handle specific size shipping containers resting on ground, as described in U.S. Patent 6,910,844. Trailer transporters are also known to handle shipping containers resting on ground. U.S. Patent 4,120,413 describes a trailer having adjustable side rails and lift cylinders to load a container onto the side rails for transportation. As well, U.S. Application 2004/0223835 published on November 11, 2004, describes a trailer having a U-shaped frame and lifting members to lift a container from a ground surface for transportation. The U-shaped frame is provided with a rear gate. The present invention is concerned with a trailer container transporter of the general type as described in these later two patents referred to.

Briefly, summarizing some of the disadvantages of prior art container road transporters, they are expensive to fabricate, bulky, time consuming to load and unload, require at least two operators, some need hoist or ground support equipment and some cannot operate on rough road conditions or maneuver to pick up containers in restricted spaces and containers resting directly on the ground without supports. Some of the trailer type transporters also do not provide adequate shock damping and can cause damage to the contents of the container during transport on rough roads .

DISCLOSURE OF INVENTION

It is a feature of the present invention to provide a trailer for transporting a container which is preferably, but not exclusively, ISO certified and capable of transporting the container on public roads by a pick-up truck or other small tractor vehicles by means of a fifth wheel attachment. Another feature of the present invention is to provide a trailer for transporting a container and wherein the trailer has a pair of horizontal side beams that are displaceably adjustable in a horizontal plane to permit handling of containers of different sizes and which facilitates the engagement of the trailer with the container.

Another feature of the present invention is to provide a trailer for transporting a container and which requires a single person to operate and to load and unload a container therefrom.

Another feature of the present invention is to provide a trailer for transporting a container and wherein the trailer is provided with connectors to secure ISO certified containers of different sizes thereto. Another feature if the present invention is to provide a trailer for transporting a container and which is comprised of displaceable horizontal side beams, each side beam being provided with a wheel suspension to permit the travel of the trailer with a container on public road surfaces or rough road surfaces while providing adequate shock absorption.

Another feature of the present invention is to provide a trailer for transporting a container and wherein the trailer can be engaged with a container disposed in a restricted space.

Another feature of the present invention is to provide a method of transporting a container from a rest position on a ground surface and wherein the container can be loaded on the trailer by a single person and in a substantially horizontal manner.

According to the above features, from a broad aspect, the present invention provides a trailer for transporting a freight container. The trailer is comprised of a frame having a front frame section adapted to be coupled to a road vehicle. The frame further has a pair of displaceable horizontal side beams. A hingeable rear gate is formed by a pair of hinged arms which are hingedly secured to a rear end of a respective one of the horizontal side beams. Each of the horizontal side beams has one or more wheels independently secured thereto by suspension means. Retractable vertical lifting means is secured to a portion of the front frame and the pair of hinged arms and actuable to lift the pair of horizontal side beams with its one or more wheels above a ground surface. Laterally extendable means is secured to the front frame and the hinge arms to displace the horizontal side beams outwardly and inwardly with respect to one another when lifted off the ground surface by the retractable vertical lifting means. Container lifting and lowering means is also secured to the front frame section and the hinge arms for removal connection to a container positioned between the side beams to lift and lower the container therebetween in a substantially horizontal plane. Container connecting means is secured to each of the side beams for securing the container thereto for transportation.

According to a further broad aspect of the present invention, there is provided a method of transporting a container from a rest position on a ground surface. The method comprises the steps of: i) providing a trailer having a frontal frame section, a pair of displaceable side beams, and a hingeable rear gate formed by a pair of hinge arms, each of the hinge arms being hingedly secured to a rear end of a respective one of the side beams, and wheels secured by suspension means to each of the side beams; ii) lifting the trailer and wheels off a ground surface by operating a retractable vertical lifting means secured to the front frame and the pair of hinge arms,- iii) extending the side beams outwardly by operating laterally extendable means secured to the front frame and the hinge arms,- iv) lowering the trailer back on the ground surface by operating the retractable vertical lifting means; v) opening the rear gate to create a rear entry opening; vi) positioning the trailer about the container from the rear entry opening; vii) closing the rear gate,- viii) engaging container lifting and lowering means with the container; ix) lifting the container above the side beams in a substantially horizontal manner; x) repeat step (ii) ; xi) retract the side beams inwardly by operating the laterally extendable means to align the side beams with corner connections of the container; xii) repeat step (iv) ; xiii) lower the container in said substantially horizontal manner onto connecting means secured to the side beams and engage the connecting means with the corner connections of the container.

According to a further broad aspect of the present invention there is provided a wheel supporting suspension for securing a wheel to opposed sides of a trailer frame. The suspension comprises a pivoted wheel support arm secured at a forward pivot end to a pivot pin retained in a frame attachment member for pivotal connection of the pivoted wheel support arm to the frame. A wheel axle assembly is secured at a rear free end of the pivot arm and adapted to connect a wheel thereto. A shock absorber connecting bracket is secured to the forward pivot end of the pivotal wheel support arm and has a shock absorber connecting member extending above the pivot pin. The shock absorber connecting member is pivotally displaceable in facial alignment with a stationary shock absorber connector secured to the frame. A shock absorber is retained captive between the shock absorber connecting member and the stationary shock absorber connector and compressible therebetween by the shock absorber connecting member being displaced towards the stationary shock absorber connector by upward movement of the pivot wheel support arm to absorb vertical displacement loads transmitted to the pivotal wheel support arm by the wheel connected thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is a side view showing the trailer of the present invention secured to a fifth wheel connection of a pick-up truck and wherein a container has been loaded onto the trailer;

FIG. 2 is a perspective view of the trailer showing some of the component parts thereof;

FIG. 3 is a top view of FIG. 2;

FIG. 4A is a rear view of FIG. 2; FIGs. 4B and 4D are perspective views of differently constructed rear gate hinge arms and locking mechanisms; FIGs. 4C and 4E are side views of the hinge arms of Figures 4B and 4D, respectively;

FIG. 4F is a fragmented perspective view illustrating the construction of the lock pin mechanism in one of the rear gate hinge arms;

FIG. 5 is an exploded view showing the construction of the retractable vertical lifting mechanism to lift the pair of horizontal side beams and its wheels above a ground surface,- FIG. 6 is a perspective view of the coupling connector connected to the lifting cylinder of the container lifting and lowering posts,-

FIG. 7 is a perspective view showing the connection of a container corner locking device for engaging ISO certified containers;

FIG. 8A is a fragmented perspective view of the transverse extendable connecting mechanism as secured to one of the rear gate hinge arms ;

FIGs. 8B and 8C are perspective views of another version of the sliding coupling assembly employing a roller cage;

FIGs. 8D to 8F are perspective exploded views and assembled side views illustrating the construction of the horizontal adjustable guide rollers and the fixed vertical guide rollers;

FIG. 9 is a further perspective view of the trailer of the present invention as seen from a different angle;

FIG. 10 is a further perspective view of the transverse extendable connecting mechanism as secured to the front frame section of the trailer but with some portions thereof having been removed to show the cylinder connection;

FIG. 11 is an enlarged fragmented view showing the construction of the container alignment pads secured on the inner face of the horizontal side beam;

FIGs. 12A and 12B are a perspective views of a pair of wheel supporting suspension constructed in accordance with the present invention for securement to a trailer frame; FIG. 13 shows two of the wheel supporting suspensions secured to a trailer side frame with one of the suspensions having the wheel removed therefrom for the purpose of illustration;

FIG. 14 is a top view showing two wheel supporting suspensions secured to the trailer side frame on an outer side of the side frame,-

FIG. 15 is a side view showing the operation of the independent suspensions when encountering obstacles on a road; FIGs. 16A to 16C are side views showing the operation of the wheel supporting suspension from an unloaded position to a fully loaded position; and

FIGs. 17A to 17K are side views showing the method of use of the trailer of the present invention for engaging a container resting on a ground surface.

MODES FOR CARRYING OUT THE INVENTION

Referring now to the drawings and more particularly to Figures 1 to 4A, there is shown generally at 10 the container transport trailer of the present invention for transporting a freight container 11 and preferably, but not exclusively, ISO certified containers. - S -

The trailer 10 has a front frame section 12 provided with a towing frame structure 13 for removable attachment to a hitch 14, herein a fifth wheel hitch, secured in the box 15 of a pick-up truck 16. It is also conceivable that instead of a pick-up truck that a tractor or a motorized cab may be constructed particularly suited to handle the trailer 10 of the present invention with the trailer 10 secured to a pivotal connection (not shown) in the rear of the cab by a different type of towing frame structure, for attachment to a coupling plate of a tractor or a pintle hook of a truck or trailer.

Details of the trailer will now be described with further reference to Figures 2 to 4A. As herein shown, the trailer 10 has a front frame section 12, as above- described, and to which is secured a pair of displaceable horizontal side beams 17 and 17' which are displaceable in substantially parallel planar relationship to one another in an outward and inward direction, as will later be described. A hingeable rear gate 18 is formed by a pair of hinge arms 19 and 19' . Each hinge arm is hingedly secured to a respective one of the horizontal side beams 17 and 17 ' at a rear end 20 and 20' of the side beams 17 and 17 ', respectively. The hinge arms 19 and 19', when in their closed position, as illustrated in Figures 2 and 3, are interlocked at their free ends by a locking mechanism 90 which is actuated by a locking arm 91 as better illustrated in Figure 4A. Details of this simple mechanism are not illustrated herein.

Referring to Figures 4B to 4F, there is shown a preferred construction of the hingeable rear gate 18. As hereinshown the rear gate hinge arms 19 and 19' are formed by an assembly of steel plates 100 and form a vertical lower housing 101 for the rear container lifting parts 25. One of the hinge arms, herein arm 19' is provided with a lock rod 102 having a beveled or tapered free end 103. A lock pin receiving hole 104 is formed in a lower face 105 of the lock rod 102. The lock rod 102 is immovably secured to the arm 19' . Therefore, as the hinge arm moves in an outward and inward direction, so does the lock rod 102.

As shown in Figures 4B, 4C and 4F, the other hinge arm 19 is provided with a lock rod receiving cavity or channel 106 dimensioned to receive the lock rod 102 thereinto whereby to interlock the two hinge arms 19 and 19' in a closed aligned position. As shown in Figure 4F, the channel 106 is provided with a friction plate 107 on a bottom wall 108 thereof and on which the lower face 105 of the lock rod 102 is displaced. A lock pin klO9 projects through a hole 110 provided at a predetermined location in the friction plate 107. The lock pin 109 is spring-biased upwardly by a spring- loaded linkage 110' secured to a spring piston 111. The top free end 112 of the lock pin 109 has a convex shape whereby when the lock rod 102 enters the channel 106, the tapered free end 103 of the lock rod will push the loc pin downward and exert a puling force on the spring piston. As the lock rod 102 further penetrates into the channel 106, to a fully closed rear gate 18, the lock pin 109 enters into the lock pin receiving hole 104 of the lock rod due to the upward force exerted on the lock pin by the spring piston 111 and its linkage 110' .

Each of the horizontal side beams 17 and 17' are provided with one or more, herein two, wheel supporting suspension assemblies 21 and 21' respectively, and independently displaceable to absorb shocks . This suspension 21 and 21' will be described in more detail later.

Retractable vertical lifting means in the form of vertically supported telescopic lifting legs 23 are secured to a portion of the front frame 12, herein adjacent opposed ends thereof, inside the horizontal side arm 17. These telescopic lifting legs 23 are also secured to each of the hinge arms 19 and 19' adjacent their inner end portions thereof. When these telescopic vertical lifting legs are extended they lift the horizontal side beams 17 and 17', as well as the wheels 22, off the ground surface. This is necessary in order to actuate laterally extendable means, namely pistons 50, which forms part of a transverse extendable connecting mechanisms 24 secured to each of the hinge arms 19 and 19' and to opposed sides of the front frame section 12 whereby to displace the horizontal side beams 17 outwardly and inwardly with respect to one another. The side beams may be displaced independently or in unison by operating the hydraulic controls 36. The trailer 10 is further provided with container lifting and lowering posts, herein four such posts 25, secured in a respective one of four corner areas of the trailer frame. These container lifting posts 25 permit removable connection to a container 11 positioned between the side beams 17 and 17' to lift and lower the container therebetween, in a substantially horizontal plane, to permit engagement of the container onto the horizontal side beams 17 and 17' as will be described later. Container connecting means in the form of container locking devices 26 are also secured on a top surface 27 of the horizontal side beams 17. Only four such container locking devices 26 are herein shown but the side beams may be fitted with attachments to removably secure additional ones of the locking devices for handling containers of different lengths. These container locking devices 26 are also adapted to secure to the attachments provided in the corners of ISO certified containers 11 or other such containers and they are well known in the art. The side beams 17 and 17' are capable of each supporting a load of 4800 lbs. for a total handling capacity of 19,200 lbs. and a total load of 22,700 lbs. on the suspension of four wheels for the "pick-up truck" version herein illustrated.

Referring to Figure 5, there is shown in exploded view, the bottom portion of the telescopic vertical support leg assembly 23 as identified in the circled portion A of Figure 2. The vertically supported telescopic leg assembly 23 comprises a steel tube 30 in which there is slidingly and telescopically received a steel post 31 constituting the leg. A hinged foot plate 32 is secured to the bottom end of the post 31 to engage the ground surface. The post 31 is slidingly received within the tube 30 and displaceable by a piston rod end connection 33 secured to the free end of piston rod 34 of piston cylinder 35. All piston cylinders 35 may be operated in unison by the hydraulic controls 36 conveniently located at the front end of the trailer 10 next to the hydraulic unit 37. Alternatively, they may be operated individually if need be to lift the container 11 substantially horizontally not to displace the freight contained therein.

Figure 7 illustrates the construction of the container locking device 26 as shown in the circled portion B in Figure 2 and this locking device is positioned to be received within the corner connectors of the container 11, as is well known in the art. Accordingly, their construction and operation will not be described herein, sufficient only to say that, as shown in Figure 3, these are located at a precise location on the top surface 27 of the horizontal side beams 17 and 17' to engage with the locking connectors in the four bottom corners of the ISO certified container.

Figure 6 is a perspective view of the circle portion C of Figure 2 but partly fragmented whereby only the mechanism mounted in the lifting post 25 is shown herein. As herein shown, a piston lifting cylinder 38 is secured within each of the posts 25 and it has a piston rod end connection 39 secured to a coupling connector 40 which has a connecting flange 42 which is vertically displaced along a vertical slot opening 41 in the lower section of the post 25, as shown in Figure 2. The connecting flange 42 which slides along the slot 40 and extends outwardly thereof. The connecting ear 42 has an attachment hole 43 to secure a chain 44 thereto. The chain 44 has a hook 45 at its end, as shown in Figure 2, to which a container coupling connector 46 is secured to engage the connectors 47 provided in the four corners of the container 11, as shown in Figure 1. These coupling connectors 46 are engaged while the container 11 is resting on the ground surface. By actuating these piston lifting cylinders 38 by the controls 36 the container is lifted off the ground in a substantially horizontal plane to safeguard its content. After the container is re-deposited onto the ground or ground supports, after transport to its destination, the connectors are disengaged. If the container is not lying horizontally, the length of the chains can be adjusted to compensate for the tilt of the container if all of the lifting cylinders are to be operated simultaneously. Figure 8A is an enlarged view of the circle portion D of Figure 2 and illustrates, in part, the construction of one version of the transverse extendable connecting mechanism 24. One of these extendable connecting mechanisms 24 is secured to opposed sides of the front frame section 12 and to each of the hingeable rear gates. The detail D shows the mechanism secured to one of the hingeable rear gates, herein gate 19. Figure 8A will be described with further reference to Figure 10 which shows part of the extendable connection 24 secured to the front frame section but with parts thereof having been removed to illustrate the entire construction. As herein shown, the extendable connecting mechanism has a hydraulic piston cylinder 50 having a piston rod end connection 51 secured to the horizontal side beams 17 and 17' and by actuating the cylinder 50, by use of the manual controls 36, the horizontal side arms 17 and 17' can be displaced outwardly and inwardly with respect to one another. To do so the side beam needs to be coupled at opposed ends to the front frame section 12 and to associated one of the hinge arms 19 and 19' by a sliding coupling assembly 52 as shown in Figure 8A.

The sliding coupling assembly 52 is constituted by a slide plate 53 which is secured to a hinge flange 54 attached to a hinge connection 55 at the rear end 20 and 20' of the side beams 17 and 17', respectively. The slide plate 53 is displaceably retained captive between guide wheels 56, one of which is not shown in Figure 8A for ease of illustration, and which are secured to the hinge arms, herein hinge arm 19, to permit sliding displacement of the slide plate 53 therebetween and along a straight longitudinal axis of the hinge arm. This slide plate 53 is shaped to extend over the cylinder 50, which is not shown in Figure 8A, but located therebehind. Accordingly, the slide plate 53 also provides a cover for the cylinder 50 to protect it from foreign matter. These guide wheels 56 are disposed for frictional rotational engagement with opposed parallel edge portions 53 ' of the slide plate 53.

Referring now to Figures 8B to 8F, there will be described a further and preferred version of the sliding coupling assembly 52. As hereinshown, the preferred sliding coupling assembly 115 is constituted by eight guide rollers, namely four horizontal, spaced-apart , adjustable guide rollers 116 and four vertical spaced-apart, fixed vertical rollers 117. The front frame section 12 is constructed from steel plates, like the hinge arms 19 and 19' . The front frame section defines square cages 118 at opposed ends thereof. The vertical rollers 117 are secured in aligned spaced-apart pairs between top and bottom plates 119 and 120 of the cage. The adjustable horizontal guide rollers 116 are secured in aligned spaced-apart pairs between opposed side plates 125 of the cage. The spacing between the pairs of rollers is calculated whereby the slide plate 52, herein constituted by a sliding connecting beam 122 of rectangular cross-section, is in friction contact between the horizontal and vertical rollers 116 and 117.

As shown in Figure 8E, the horizontal adjustable guide rollers 116 are constituted by a cylinder roll 125 in which there is fitted a core rod 126 of circular cross- section and dimensioned for close sliding fit inside the cylinder roll 125. The core rod 126 has an eccentric rod end 127 at a far end thereof and retained in close rotational fit in a hole provided in an inner one of the opposed side plates 121. the core rod 126 is also provided with an engageable head 128 at a rear end spaced forwardly of a support ring 129 adapted for retention fit in a support hole 130 formed in an outer one 121' of the side plates 121 of the cage 118. A torque coupling 131 secures about the engageable head 128 and has an extension connecting arm 132 having a hole 133 therein to receive a connecting bolt 134 therethrough. A series of threaded bolt receiving holes 135 are disposed on a radius on an exterior surface 136 of the outer side plate 121' . Thus by rotating the torque coupling 131 the cylinder roll 127 is displaced on its eccentric connection and is displaced towards or away form its frictional engagement with the sliding connecting beam 122 to compensate for wear adjustment. Further, the guide rollers 116 and 117 are replaceable individually to permit easy replacement.

The vertical rollers 117 are not adjustable but secured in a like fashion as the horizontal adjustable rollers 116. The construction of the vertical rollers 117 is shown in Figure 8F and as can be seen the rod end 138 of its core rod 139 is centrally disposed along the longitudinal axis 140 of the vertical roller 117.

As shown in Figures 9 and 11, each of the side beams 17 and 17 ' are provided with container alignment pads 58 on the inner surface 17''' . Figure 11 is an enlarged view of the circle portion E shown in Figure 9 which illustrates the shape and location of the pads 58. These container alignment pads 58 protect the inner side surface 17 ' ' ' of the horizontal side arms 17 and 17' while the trailer is backed-up about the container 11. They also provide guides when the trailer is backed into and about the container from the rear open gate, as will be described later. Also, and as shown in Figures 3 and 5, one or more bumpers 59 are secured to the inner side wall 59' of the front frame section 12 to provide an abutment against the container forward end when the trailer is backed in around the container.

With reference now to Figures 12A to 16C, there will be described the construction and operation of the wheel supporting suspension assembly 21. There are two suspension wheel assemblies 21 shown in Figures 12A and 12B and shown in engagement with the side beam 17 of the trailer on an outboard side thereof. Figure 12B shows a steel plate frame construction which is laser cut and easy to assemble. Like designation numbers are used for referencing the parts . As shown in Figure 13 there are two such wheel supporting suspension assemblies secured to each of the opposed side beams 17 and 17' and these suspensions operate individually. Each suspension assembly is comprised of a pivoted wheel support arm 60 secured at a forward pivot end to a pivot pin 61 (see Figure 13) retained in a flame attachment member 62 for pivotal connection of the pivoted wheel support arm to the side beam 17 of the trailer frame.

A wheel axle assembly 63 is secured at a rear free end of the pivot arm 60 and adapted to connect to a wheel 22 as previously described and illustrated in Figure 2, for example. A shock absorber connecting bracket 64 is secured to the forward pivot end 65 of the pivotal wheel support arm 60 and has a shock absorber connecting member 65 extending above the pivot pin 61 and spaced therefrom. A shock absorber connecting member 65 in the form of a flat seating plate is secured to a support frame 66 which forms part of the shock absorber connecting bracket 64. A connecting fastener in the form of a bolt 67 secures a compressible shock absorber 68 in facial contact therewith and in a manner well known in the art.

As shown in Figure 13 , when the wheel supporting suspension assembly 21 is secured to the side beam 17, the shock absorber seating plate 65 is disposed in facial spaced relationship with respect to a stationary shock absorber connector, herein a flat seating wall 69 formed at the front end of a recessed wall portion 70 formed in the outboard portion of the side beams. There are two such recessed wall portions which are spaced-apart . The shock absorber pad 68 is retained captive between the shock absorber connecting plate 65 and the stationary vertical seating plate 66 and compressible therebetween by the shock absorber connecting member, herein the plate 65, being displaced towards the stationary shock absorber plate 66 by the load imposed by the trailer frame and any additional load supported thereon which causes pivotal upward movement of the wheel support arm to absorb vertical displacement loads transmitted to the arm by the wheel connected thereto and resting on the ground surface.

As shown in Figures 12A, 12B and 13 , the pivotal wheel support arm 60 is also provided with a lateral displacement stabilizing vertical extension plate 71 immovably secured to the pivotal wheel support arm 60. The extension plate is provided with a vertical flat friction surface 71' which is displaceable against a flat vertical arresting surface, herein the vertical wall 70' of the recess well portion 70 of the side beam on an outboard side of the side beam. This plate prevents lateral displacement of the support arm. As well, to add further lateral stability there is provided a bushing 72 of shock absorbing material immovably retained in the frame attachment member 62 as better seen in Figure 15 and disposed about the pivot pin. This stabilizes the pivot pin joint and absorbs forces that may be transmitted to the pivot pin. It is pointed out that the vertical flat friction surface 71' of the vertical extension plate 71 is provided by an ultrahigh molecular weight polyurethane plate which is secured to a surface of the vertical extension plate by a fastener, such as fasteners 71" shown in Figures 12A and 12B. The wheel supporting suspensions 21 are secured to an underface of the side beam 17 by bolt fasteners or welding of the frame attachment member 62, herein a connector plate 62' to the undersurface of the side beam forwardly of the recessed wall portions or cavities 70. The top view of Figure 14 illustrates the position of the wheels 22 with respect to the suspension assembly 21. Figure 16A shows the suspension assemblies 21 when secured to the trailer side beams 17 without a container connected to the trailer. The weight of the trailer is approximately 1250 lbs. Figure 16B illustrates the suspension in partial compression when the trailer is loaded with a load of approximately 22,700 lbs. As herein shown, the shock absorbers are compressed. Figure 16C shows the shock absorbers in maximum compression. It is pointed out that this suspension assembly

21 was designed to be able to take a total load of 22,700 lbs. without a thru axle extending across the frame as between two wheels, as is conventional with tractor trailers. This suspension was designed whereby each side of a trailer is independent from the other side. The smoothness of the ride is assured by the independent suspension and shock absorbers. As shown in Figure 15, while one wheel is pushed up in the direction of arrow 76 by a bump 75, thus creating a sudden load increase, the other wheel, herein wheel 22', will remain independent. When the pivotal arm 60 is at the end of its travel, the shock absorber 78 will be squeezed to absorb the energy. Both shock absorbers work independently.

As shown in Figure 13, the spindle 63" of the wheel axle assembly 63 provides the link between the bearing (not shown) and the drum 63' ' ' (not shown) . It is attached to the axle 63' and it is a non-moving part of the wheel end. The drum 63''' is the link between the wheel 22 and the spindle. The wheel 22 is attached to the drum and the drum rotates on the spindle bearing (not shown) . Electric brakes (not shown) are located inside the drum and help the pick-up truck and trailer to brake faster and safer.

Referring again to Figure 8A, a manual locking device 80 is provided adjacent opposed ends of the side beams 17 and 17 ' , only one being shown herein, to lock the side beams with respect to the front frame section 12 when displaced to an outward extended position and to also lock the hinge arms 19 and 19' in an open position, substantially in alignment with the side beams when the side beams are in their outward position. Any convenient manual locking device may be provided to effect this interlocking and, as herein shown in Figure 8A, a lock pin 81 is displaceably retained in a bracket 82 secured to the lifting post 25 whereby to engage with a further bracket 83 extending from the wheel supporting top plate 84 of the guide wheels 56. The bracket 83 is also provided with a hole 85 to receive the locking bolt 81 in locking engagement therewith. Having described the construction of the container transport trailer 10 of the present invention, there will now be described its method of use.

With reference now to Figures 17A to 17K there is now described the method of engaging the trailer 10 to the freight container 11. Firstly, as shown in Figure 17A, the pick-up truck 16 positions the trailer 10 near the container 11 and in straight alignment therewith and far enough to provide sufficient space to open the rear gate 18. The rear gate is unlocked. The operator then starts the hydraulic unit 37 and, using the hydraulic controls 36, causes the telescopic lifting legs 23 to be extended, as shown in Figure 17B, and sufficiently to lift the trailer and its support wheels 22 off the ground surface 93. The four corners of the horizontal side arms 17 is manually unlocked from the locking mechanisms 80 and again using the hydraulic controls 36, the pistons 50 are actuated whereby to displace the opposed side beams 17 and 17' outwardly to enlarge the space therebetween sufficient to permit the trailer to be safely backed up around the container without damage to the trailer or the container. As the side beams move away from one another, the lock rod 102 moves out of the lock channel 106 of the rear gate hinge arms as the cylinder 111 is actuated to unlock. The hinge arms 19 and 19' of the rear gate are then locked in their open position by the locking mechanism 80. The telescopic lifting legs 23 are then lifted by the hydraulic controls 36 so that the trailer wheels are again resting on the ground. The trailer is then ready to be backed up about the container, as shown in Figure 17C.

The operator of the pick-up truck 16 slowly backs the trailer about the container 11 until the container hits the bumper 59 secured to the inner face of the front frame section 12. The operator then engages the parking brake on the pick-up truck and is now in a position to load the container, as shown in Figure 17E. With the use of the hydraulic controls 36, the coupling connectors 40 in the container lifting post 25 are lowered and the connector 46 is positioned adjacent a corner of the container where the connectors 46 are engaged within the corner connectors 47 of the container 11. This attachment to the container is done manually by the operator in the four corners of the container. The lifting cylinders 38 in the container lifting posts are then actuated in unison or independently to adjust the level of the container. The cylinders 38 withdraw the coupling connector 40 upwardly whereby to lift the container above the horizontal side arm 17, as shown is Figure 17G in a substantially horizontal manner. This position is also shown in Figure 17H. Figure 17F shows a container lying on the ground prior to being lifted. As shown is Figure 17G, the container lies above the container locking devices 26 on the top surface of the horizontal side beams 17 and 17' . At this position the lifting cylinders are at their end of travel and the container is lifted substantially horizontally not to disturb its cargo or freight. With the container positioned as shown in Figure

17G the horizontal side beams 17 and 17' and their wheels 22 now need to be lifted off the ground surface 93 by the actuation of the telescopic lifting legs 23 and this is illustrated in Figure 171. The wheels 22 should not touch the ground surface when lifted to that position. The hinged rear gate arms 19 and 19' are closed. The pistons 50 are then actuated by the hydraulic controls to retract the horizontal side arms 17 and 17 ' to their original closed positions where the container locking devices 26 should be aligned with the lower corner connectors 47 of the container 11 and the rear gate arms now locked. The telescopic lifting legs 23 are then retracted so that the wheels are again in engagement with the ground surface 93. Thereafter, the coupling connectors 40 in the container lifting post 25 are lowered by the use of the hydraulic controls 36 to position the corner connectors in the locking devices 26 where they are then engaged with the horizontal side arm 17 of the frame of the trailer 10. After the container locking devices are engaged the operator inspects the trailer to ensure that all locking devices are secured in position. The trailer is now ready to transport the container to a further location where the container is unloaded by going through the same process but in reverse mode .

It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.