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Title:
APPARATUS FOR LIFTING AND TRANSPORTING A CONTAINER
Document Type and Number:
WIPO Patent Application WO/2007/106735
Kind Code:
A2
Abstract:
The invention relates to an apparatus and method for the transportation and delivery of a portable storage unit (14). The apparatus includes a frame (10) with selectively controllable dimensions to lift and lower the portable storage unit. A separate power source (12) links with the frame in order to provide a means to actuate the frame's dimensions. The independent power source is also self-propelled and is operable to push, pull, or relocate the frame across a surface. The frame, storage unit, and power unit are loaded onto a road vehicle (70) in order to transport them between various work or storage sites. The frame includes hydraulic cylinders (26, 27) that work to change the dimensions of the frame, and the hydraulics are activated and controlled via a hydraulic connection (not shown) with the mechanized power unit.

Inventors:
MCGURN ARTHUR S (US)
Application Number:
PCT/US2007/063658
Publication Date:
September 20, 2007
Filing Date:
March 09, 2007
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
MCGURN ARTHUR S (US)
International Classes:
B65G1/00; B65G65/00
Foreign References:
US6155770A
US4699558A
US6071062A
US20030180132A1
US6431805B2
Attorney, Agent or Firm:
RARING, Alexander, D. (P.C536 Granite Avenu, Richmond VA, US)
Download PDF:
Claims:

What Is Claimed Is:

1. An apparatus for transporting, delivering, or otherwise positioning a

portable storage unit, the apparatus comprising:

a wheeled frame, the frame having height, width, and length dimensions

with four corners defining two sides and two ends, the frame including:

a vertical post at each of the four corners,

a leg extending from the lower end of each post, the leg being

selectively extendable or retractable relative to the post to change the vertical

height of the frame,

a selectively pivotable wheel assembly supporting each leg,

a cross-member on each side of the frame, each cross-rnember

connected to two of the posts,

an end-tube on each end of the frame, each end-tube connected to

two of the fixed posts,

an interior tubular element in each end-tube, the end-tube

selectively slidable upon the tubular element to change the width of the frame,

at least one connector that connects the frame to the portable

storage unit,

at least one hitch mount on the frame,

a self-propelled power unit selectively secured to the at least one

hitch mount, the power unit including selectively attached couplings to

transfer energy from the power unit to the frame to change the dimensions of

the frame, the self-propelled power unit operable to move the frame across a

surface, and the power unit being positionable independent of the frame; and

wherein the frame and the selectively removable power unit are effective

to lift and position the portable storage unit.

2. The apparatus of claim 1, wherein each selectively pivo table wheel

assembly further comprises an upper plate joined to the bottom of the

corresponding legs, a revolving caster assembly connecting a rotatable wheel to

the upper plate, and a selectively removable pin wherein the pin is operable to

lock the revolving caster assembly in place.

3. The apparatus of claim 1, wherein the vertical posts and legs slide

relative to each other via hydraulic cylinders that motivate the leg to slide

relative to the corresponding post and wherein the selectively removable power

unit supplies the hydraulic pressure to actuate the hydraulic cylinders.

4, The apparatus of claim 1, wherein the end-tubes and the interior

tubular elements slide relative to each other via hydraulic cylinders that

motivate the end-tube to slide relative to the corresponding tubular element

and wherein the selectively removable power unit supplies the hydraulic

pressure to actuate the hydraulic cylinders.

5, The apparatus of claim 1, further comprising a lift position for the

frame, the lift position describing a position wherein the legs extend from the

corresponding posts a sufficient distance to raise the end-tubes of the frame

above the height of the container; and

wherein the power unit is operable to separate the location of the frame

from the location of the container by motivating the frame away from the

container when the frame is in the lift position.

6. The apparatus of claim 1, wherein the at least one connector that

connects the frame to the portable storage unit further comprises a chain, the

at least one chain being secured to the frame at a first end and secured to the

portable storage unit at a second end.

7. The apparatus of claim 6, wherein the at least one chain is secured to

a cross-rnernber at the first end of the chain.

8. The apparatus of claim 1, wherein the wheeled power unit includes a

hitch receiver selectively secured to the hitch mount, the hitch mount

comprising a ball mount assembly.

9- The apparatus of claim 1, further comprising a transport vehicle, the

transport vehicle including a flat bed; and wherein the bed includes channels

sized and dimensional to accept the legs and a mounting system to support the

power unit.

10. An apparatus for transporting, delivering, or otherwise positioning a

portable storage unit at a specific location, the apparatus including a

dimensionally adjustable frame, the apparatus comprising:

a plurality of selectively pivotable wheel assemblies supporting the frame

for movement across a support surface;

at least one connector that connects the frame to the portable storage

unit;

at least one hitch mount connected on the frame;

a self-propelled power unit selectively coupled to the frame, the power

unit including a hitch receiver selectively secured to the at least one hitch

mount, the power unit including hydraulic couplings mated to the frame, the

dimensions of the frame controlled by actuating hydraulic cylinders in the

frame via hydraulic pressure supplied by the power unit, the propulsion of the

wheeled power unit effective to motivate the frame across the support surface;

and

wherein the frame and the selectively removable power unit are operable

to lift and position the portable storage unit.

11. The apparatus of claim 12, further comprising a transport vehicle,

the frame and power unit operable to be stored on the transport vehicle.

12. The apparatus of claim 12, wherein each of the plurality of

selectively pivotable wheel assemblies further comprise an upper plate secured

to the corresponding leg, a revolving caster assembly connecting a rotatable

wheel to the upper plate, and a selectively removable pin wherein the pin is

operable to lock the revolving caster assembly in place.

13. The apparatus of claim 12, wherein the frame is constructed of pairs

of nested tubes, each tube in the pairs of nested tubes arranged in a sliding

relationship to the other tube of the pair, a plurality of hydraulic cylinders

operable to slide one tube in each pair relative to the second tube.

14, The apparatus of claim 12, wherein the least one connector that

connects the frame to the portable storage unit further comprises a chain, the

at least one chain being secured to the frame at a first end and secured to the

portable storage unit at a second end.

15, A method of relocating a temporary storage container:

driving a transport vehicle to a desired location, the transport vehicle

supporting a storage container, a wheeled frame, and a self-propelled power

unit wherein the frame is linked to the storage container;

creating a hydraulic connection between the self-propelled power unit

and the frame;

supplying hydraulic pressure to increase the height of the frame and

storage container relative to the transport vehicle;

furnishing hydraulic pressure to increase the width of the frame;

using the self-propelled power unit to move the wheeled frame;

removing hydraulic pressure to reduce the height of the frame in order to

rest the storage container on a surface;

disconnecting the storage container from the frame; and

repositioning the frame on the transport vehicle via the self-propelled

power unit.

Description:

APPARATUS AND METHOD FOR LIFTING AND TRANSPORTING A CONTAINER WITH AN INDEPENDENT MECHANIZED UNIT

Inventor: Arthur S. McGurn

APPARATUS AND METHOD FOR LIFTING AND TRANSPORTING

A CONTAINER WITH INDEPENDENT MECHANIZED UNIT

The present invention relates to a method and apparatus for lifting and

relocating containers. More specifically, the apparatus and method provide a

frame and a independent mechanized/ power unit that combine to deliver a

portable and temporary storage option

Background

The temporary storage industry, also known as the self-storage industry,

is a multi-billion dollar industry serving the needs of an increasingly

consumptive and mobile public The most common type of self-storage is a

secure location where paying subscribers or renters are allowed access in order

to place their possessions or goods in individual storage units. The customer is

responsible for locating a reputable storage provider and transporting their

goods to the remote site The customer can pick up or deposit goods as

needed, but the storage provider's only service is to provide a secure location

for the customer These remote storage units may not be readily accessible to

the customer. In addition, temporary use of off-site storage, for instance where

a customer is temporarily storing their possessions during a relocation,

introduces additional loading and unloading steps to the relocation process.

More recently, storage customers have begun a shift to on-site storage

wherein containers of various sizes are delivered to the customer- The

increased convenience and accessibility benefit the customer. The storage

provider also has decreased overhead (real estate taxes, liability, etc.). On-site

storage allows a customer to store their possessions that do not fit in the

customers structure, either commercial or residential. It should be noted that

storage customers range from residential renters and home owners up to

commercial entities who need piecemeal storage solutions.

Another benefit of providing on-site storage is that once the goods are

stored, the container can be moved directly to a remote storage facility or to

any other location at the customer's request These containers are generally

relatively small in order to be lifted by fork lifts. On-site storage eliminates the

extra loading and unloading steps required by off-site storage.

In many instances, in both residential or commercial applications, there

exists a need for a large size storage container that cannot be transported by

conventional means. The on-site storage industry is relatively new, but it has

encountered problems with transporting these containers to the site, unloading

the containers from the transport vehicle, and maneuvering the container into

the desired position Forklifts are inadequate and cranes are cost prohibitive.

The delivery process also must be reversed when the container is to be removed

from the site, The method of delivering the container must be low impact to

the customer's site while offering a secure means to transport the goods. The

delivery method should also keep the load level without excessive tilting.

In response to this recognized need, one industry solution has been the

creation of a motorized frame for lifting and handling a storage container,

loading it onto a vehicle, transporting it to a given location, and unloading the

container from the vehicle.. The typical solution is to have the motor on the

frame, which increases the complexity of the frame. Drive shafts and other

components must be integrated into the frame to handle the integral power

unit. In addition, steering components must be built into the frame. All the

parts that must be integral to the frame means increased complexity and that

any maintenance problems for the mechanized portion of the frame disables

the entire frame. Mounting the motor on the frame also leads to a potentially

unbalanced frame, among other issues.

Therefore, there exists a need for an apparatus and method that provide

a separate frame and power unit that combine to deliver a portable and

temporary storage option. It is preferred that such an apparatus and method

would allow for a separate, self-propelled power unit that selectively links to

the frame. An apparatus for lifting and transporting a container with an

independent mechanized unit in accordance with the present invention allows

a temporary storage container to be transported or otherwise delivered in a

more efficient and reliable manner- The independent power/ mechanized unit

increases mobility in at least some circumstances and can be quickly

exchanged for another unit. As described below, the present invention builds

upon conventional concepts, methods and designs of the prior art, but it

provides an original apparatus and method for improving the prior art.

Summary of the Invention

In accordance with the present invention, an apparatus and method are

provided for the transportation and delivery of a portable storage unit. The

apparatus includes a frame with selectively controllable dimensions to lift and

lower the portable storage unit. A separate power source links with the frame

in order to provide a means to actuate the frame's dimensions. The

independent power source is also self-propelled and is operable to push, pull,

or otherwise relocate the frame across a surface The frame storage unit,

and /or power unit are loaded onto a road vehicle in order to transport them

between various work or storage sites. The frame, in one preferred

embodiment, includes hydraulic cylinders that work to change the dimensions

of the frame, and the hydraulics are activated and controlled via a hydraulic

connection with the mechanized power unit.

In greater detail, the frame is supported by wheel assemblies. The

height, width, and length dimensions of the frame are defined by four vertical

corner posts defining two sides and two ends Each vertical post is located at

each of the four corners with a selectively pivotable wheel assembly supporting

the post. A cross-member is positioned on each side of the frame, and each

cross-member connects to the two adjacent corner posts defining one side of

the frame. End-tubes are located on each end of the frame, and each end-tube

is connected to the two adjacent corner posts defining one end of the frame.

The height of the frame is variable in that each of the vertical posts

includes a selectively extendable or retractable leg to change the vertical height

of the frame. In addition, each of the end-tubes includes a selectively

extendable or retractable tubular element to change the width of the frame.

Therefore, the height and width dimensions of the frame can be controlled.

The ability to vary the dimensions of the frame renders the frame

operable to lift and position a storage unit. The frame is sized to substantially

fit around the dimensions of the portable storage unit. At least one connector

selectively secures the frame to the portable storage unit. Once the connection

is made, the legs are extended from the posts until the frame lifts the storage

unit off the ground.

In order to position the storage unit, the self-propelled, wheeled power

unit is selectively secured to a hitch mount located on the frame In addition,

couplings from the power unit provide the hydraulic or other force necessary to

change the dimensions of the frame from the power unit to the frame. The self-

propelled mechanized unit also pushes, pulls or otherwise positions the wheel-

supported frame across a surface.

The apparatus and method to deliver a portable storage option of the

present invention effectively address at least one of the problems associated

with prior art storage delivery systems. For instance, the storage delivery

system of the present invention includes a readily exchangeable power source

and propulsion method that eliminates or minimizes maintenance down-time

associated with prior art storage delivery systems. The frame is less complex,

and less expensive to manufacture. The foregoing and additional features and

advantages of the present invention will become apparent to those of skill in

the art from the following detailed description of a preferred embodiment taken

in conjunction with the accompanying drawings

Brief Description of the Drawings

Figure 1 is a side view of a wheeled frame hitched to a self-propelled,

wheeled power unit in accordance with one embodiment of the present

invention;

Figure 2 is an end view of the wheeled frame hitched to the power unit of

the present invention wherein the frame is illustrated in a lowered position so

that a portable storage unit rests on the ground;

Figure 3 is a close-up view of a hitch assembly operable to selectively

hitch the self-propelled power unit to the wheeled frame in accordance with one

embodiment of the present invention;

Figure 4 is a side view of the wheeled frame unit in a raised position

wherein a portable storage unit is lifted off of the ground;

Figure 5 is an end view thereof and further illustrates the ability to

change the width dimensions of the wheeled frame;

Figure 6 is a cut-away end view that illustrates internal features of the

wheeled frame in a lowered position;

Figure 7 is a cut-away end view that illustrates internal features of the

wheeled frame in a raised position;

Figure 8 is a perspective view of the wheeled frame positioned on a

transport vehicle;

Figure 9 is a perspective view of the wheeled frame positioned on a

transport vehicle wherein the wheeled assemblies are extended to lift the frame

off of the transport vehicle;

Figure 10 is a perspective view of the wheeled frame in a raised and

widened position in order to fully disengage the frame from the transport

vehicle; and

Figure 11 is a perspective view of the wheeled frame selectively hitched to

the self-propelled, wheeled power unit wherein the frame is disconnected from

a portable storage unit.

Detailed Description

Turning now to a detailed description, Figures 1 through 11 illustrate

one or more preferred embodiments of the present invention. Naturally, an

engineer having ordinary skill in the art will be able to create a storage delivery

system, that incorporates the teachings of the present invention, but which may

look different and incorporate different, alternative parts, The inclusion of a

self-propelled power unit to provide energy and locomotion, among other

features, creates a storage delivery system that is efficient and unique. The

apparatus and method improves upon out-dated systems using integrated

power units, integrated drive and steering means, and other unnecessary

components..

With reference to Figure 1 , there is illustrated an apparatus for lifting

and transporting a portable storage container including a wheeled frame 10

and an independent, self-propelled power unit 12. Frame 10 is dimensioned to

surround a portable storage container, which is illustrated as element 14.

Container 14 is represented in broken lines as the size, shape, or construction

of the storage container do not form a significant part of the invention.

Typically, however, such containers have rectangular dimensions and are

seven or more feet tall. The containers are generally fully enclosed so as to

operate as long term storage solutions. A door allows access into one or both

ends of the container.

Overall, frame 10 is rectilinear with four corners defined by vertical posts

20 so that the frame has two sides and two ends. The frame, including the

posts, is comprised of hollow tubes, and the tubes are joined by brackets,

welds, or otherwise secured together. At least one tube is used to adjoin each

adjacent post in order to provide structural integrity, As such, one or more

cross-members are provided on each side of the frame. As illustrated, a

preferred embodiment includes upper and lower cross-members 22, 24

connected at each end to the two posts defining one side of the frame (i.e.,

there are four cross-members in total). End-tubes also support posts 20 along

the end edges of the frame Referencing Figure 2, there is illustrated an end-

tube 26. Each end of frame 10 would include at least one end-tube spanning

the distance between the vertical posts that define the ends of the frame

The various joints and connections between the posts 20, cross-members

22, 24, and end-tubes 26 can be accomplished via techniques known in the

art. In addition to the above frame construction, each post surrounds and is in

a relatively slidable relationship with a leg 27. Each leg extends from, or

retracts into, the lower end of the corresponding vertical post 20, Energy

provided by the power unit 12, such as hydraulic pressure, is operable to

extend or retract leg 27 relative to the post. Legs 27 can be fully retracted into

post 20. The end-tubes also include an internal member wherein the end-

tubes are moveable in relation to the internal members. The width of the frame

is controlled via the position of the end tubes relative to the internal members,

as will be discussed further below.

Frame 10 is selectively coupled to container 14 via one or more

connectors 28. In a preferred embodiment, connectors 28 comprise brackets

30 that clamp or are otherwise secured to lower cross-members 24. A chain 32

is secured to each bracket at a first end and to the container at a second end.

Extending legs 27 lifts the frame. Figure 1 illustrates that legs 27 have been

extended to the extent that chain 32 is taunt but container 14 remains resting

on the ground /surface. The further extension of legs 27 results in container

14 being lifted off of the ground by the frame via the connectors 30. It should

be understood that many different types of connectors are available and would

be obvious to one of skill in the art.

Each leg 27 and post 20 assembly is supported by a selectively pivotable

wheel assembly 34. At least one leg includes a hitch mount 36 to which the

wheeled power unit can be selectively coupled. In one preferred embodiment, a

hitch mount is provided on a pair of opposing posts 20. The propulsion

provided by power unit 12 when power unit 12 is secured to a hitch mount is

the motivating force to move and position frame 10.

With reference to Figures 2 and 3, legs 27, pivotable wheel assembly 34,

hitch mount 36, and a receiving hitch 38 are illustrated in greater detail Legs

27 terminate at their lower end on the exterior of the respective post 20 at a leg

plate or flange 40. The upper terminus of legs 27 terminate within posts 20..

Each leg plate 40 is effectively a flat surface, arranged perpendicular to the axis

of the legs, that extends beyond the perimeter of leg 27.

Wheel assemblies 34 include an upper plate 42 secured to leg plate 40

via known fastening mechanisms such as bolts 44. Plate bolts 44 extend

through both the upper plate and post plate. A nut 46 on each bolt 44 holds

the bolt in place. Other fastening mechanisms could be used.

Each wheel assembly 34 is effectively a large scale caster. Therefore, a

rotating caster assembly 48, as known in the art, provides the ability to rotate

the direction of the wheel assembly through 360 degrees of rotation about, the

axis defined by the leg and post assembly The rotating caster assembly

includes an axle 50 onto which a wheel and tire combo 52 is mounted. The

wheel and tires rotate on the axle

The ability to rotate each wheel assembly independently increases the

mobility of frame 10. However, it is often desirable to lock one or more of the

rotatable caster assemblies in a specific direction to aid steering the frame, A

pin (not illustrated} can be inserted into or through the rotating caster

assembly in order to prevent the rotation of caster assembly 48 Locking all

four caster assemblies is possible. Safety, noise, and other considerations are

thought to make it desirable to lock the caster assemblies when frame 10 is

loaded onto a transport vehicle, as will be discussed further below.

As briefly mentioned above, power unit 12 is selectively coupled to a

hitch mount 36 One preferred embodiment of the hitch mount is a common

ball hitch as known in the art. This preferred embodiment includes a hitch

plate 54 that is fastened to a leg plate 40 and /or surrounds leg 27. Hitch plate

54 supports a hitch ball 56. Power unit 12 has a corresponding receiving hitch

38 In this case, hitch receiver 38 engages ball 56, Power unit 12 has a range

of rotation about this mounting point. In another preferred embodiment, it is

envisioned that a hitch assembly that precludes rotation between the power

unit and frame could be used.

One skilled in the art will be able to modify other known hitch assemblies

for use with the present invention. Therefore, the present invention should not

be limited to the use of a ball hitch mechanism. Moreover, given that multiple

hitch mounts on the frame is preferred, the operator can selectively lock the

necessary caster assemblies based on which hitch mount out of the plurality of

hitch mounts the operator chooses to engage.

Power unit 12 includes the necessary fluid or electrical couplings (not

illustrated) to provide hydraulic pressure or energy to frame 10. This pressure

or energy operates to alter the dimensions of the frame. In a preferred

embodiment, the power unit couplings from the power unit enter a junction

box/ controller that distributes the pressure or energy through a conduit

system mounted to the various tubes .

A preferred means for changing the height and width dimensions of

frame 10 is through hydraulic pressure supplied by power unit 12. In general,

hydraulic controls and the means to hydraulically extend one tubular element

relative to another tubular element are well known in the art. A hydraulic

pump on the power unit (not illustrated} sends hydraulic pressure to the frame

via the power unit couplings. The hydraulic pressure actuates hydraulic

cylinders located in the frame tubes.

Figure 4 illustrates the present invention wherein the height of the frame

has been raised by hydraulically extending legs 27 relative to posts 20. As

lower cross-members 24 are lifted away from the surface upon which frame 10

rests, connectors 28 between frame 10 and container 14 lift container 14 off of

the surface/ground. Once lifted, it is possible to relocate frame 10 and

container 14 via the self-propelled power unit,

As briefly discussed above, it is also desirable to change the width

dimensions of frame 10. Therefore, end-tubes 26 are in a slidable relationship

with fixed interior tubular elements 60 Figure 5 illustrates one end of frame

10 wherein end- tube 26 is hydraulically actuated to expose interior tubular

element 60. Exposing fixed element 60 increases the width of frame 10. As

end-tube 26 slides to expose element 60, the wider frame 10 becomes.

Hydraulic pressure can be reduced to move end-tube 26 over element 60,

which decreases the width of frame 10,

Figures 6 and 7 broadly illustrate the hydraulic components of frame 10.

An internal bore 58 includes a rod 59 Hydraulic pressure moves rod 59 into

and out of bore 58. The movement is transmitted to leg 27, which then

extends and retracts relative to post 20.

The present invention includes hydraulic pressure equalizing valves (not

illustrated) to balance the distribution of hydraulic force. In known temporary

container delivery systems, the operator is required to individually actuate

hydraulic cylinders or to manually distribute the lifting force, In a preferred

embodiment of the present invention, the frame incorporates the equalizing

valves to facilitate operation of the hydraulic cylinders A valve is in fluid

connection with the hydraulic cylinders located in the two posts that define one

side of the frame. Each side of the frame includes such a valve. A third

equalizing valve is in fluid connection with the hydraulic cylinders located in

the end-tubes. The valves evenly distribute the hydraulic pressure between the

hydraulic cylinders to which they are connected As a result, each side of the

frame extends the corresponding legs 27 at the same rate, and the width of the

frame uniformly increases or decreases at both ends of the frame.

Power unit 12 is motorized, self-propelled and is operable to relocate the frame

when frame 10 is not connected to a container that is resting on a surface (i.e.,

there is no container attached to the frame or legs 27 are extended to the point

that a connected container is no longer resting on the support surface). After

securing the hitch mount, unit 12 is capable of steering the frame as desired in

order for the power unit to position the frame to either deliver or extract

container 14,. The hydraulic/ power couplings must be connected to change the

frame's dimensions.

To deliver the container, the frame, while suspending the container, is

pushed or pulled to the proper location by the power unit and legs 27 are

hydraulically retracted into posts 20 to the point that container 14 rests upon

a surface. Connectors 28 are disconnected from container 14, The operator

then sends hydraulic pressure back to the frame in order to extend legs 27 to

the extent that the height of end-tubes 26 exceed the height of container 14

(see Figure 11). In this position, referred to as the lift position, it is then

possible to drive or remove frame 10 from container 14 in either direction along

the longitudinal axis of the container The width of the frame is such that the

power unit is outboard the width of the container. The ability to remove the

frame in either direction is thought to be highly advantageous given the variety

of locations to which a container may be delivered.

Although the power unit and frame can place the container once the

assembly is on-site, it is still necessary to transport the frame, power unit, and

container large distances between various sites. In this regard, as illustrated

in Figure 8, a transport vehicle 70 is provided. Vehicle 70 includes a flat bed

loading surface 72. The bed includes channels or reduced width notches 74

that open to the sides of the bed/vehicle at four positions corresponding to the

location of legs 27 on frame 10. Channels 74 are sized and dimensioned to

accept legs 27»

The frame, container, and power unit are first loaded onto the transport

vehicle. To accomplish this, hydraulic pressure from power unit 12 expands

the width dimension of the frame until the distance between two posts 20

forming one end of the frame is larger than the width of bed 72, The height of

the legs 27 is also adjusted to the point that the end-beams, cross members,

and the bottom of container 14 are all higher than the top of bed 72. Power

unit 12 then positions the frame so that legs 27 are aligned with notches 74,

The width of frame 10 is then decreased to pull legs 27 into the channels.

Power unit 12 is then disconnected from the hitch mount, and legs 27 are

hydraulically retracted into posts 20 until lower cross members 24 rest upon

bed 72 and wheel assemblies 34 are no longer in contact with the ground. The

hydraulic couplings from the power unit may be disconnected at this point.

Power unit 12 is mounted to the rear of bed 72 by a known mounting

technique, such as a elevator platform 76. Finally, the caster assemblies are

preferably locked against rotation. The vehicle is then operable to deliver

container 14, frame 10, and power unit 12 to a desired location.

To unload frame 10, the process is basically reversed. Vehicle 70 arrives

at a site where container 14 is to be delivered. Frame 10, power unit 12, and

container 14 are all located on the vehicle's flat bed 72 {see Figure 8). The

caster assemblies are first released for rotation. Power unit 12 is unloaded

from bed 72 and placed in hydraulic or electrical connection with frame 10

(again, couplings not illustrated). Legs 27 are extended from posts 20 until the

wheel assemblies are on the ground {see Figure 9). The legs extend until frame

10 lifts container 14 off the bed via connectors 28. The hitch receiver on power

unit 12 is coupled to the hitch mount provided by one of the legs at the rear of

vehicle 70. The width of frame 10 can then be expanded., Power unit 12 then

pulls the frame and container away from the vehicle. It is also envisioned that

vehicle 70 might drive away once frame 10 is clear of bed 72 (see Figure 10)- It

is likely that legs 27 will be partially retracted to create a lower center of gravity

prior to pushing or pulling the frame to the desired delivery location.

Although the present invention has been described in terms of at least

one preferred embodiment, it will be understood that numerous variations and

modifications may be made without departing from the invention Such

variations and modifications will become apparent and obvioxis to one skilled in

the art, and all equivalent relationships to those illustrated in the drawings and

described in the specification are intended to be encompassed by the present

invention. Thus, it is to be understood that within the scope of the appended

claims, the invention may be practiced otherwise than as specifically described

above.