Note: Descriptions are shown in the official language in which they were submitted.
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A UNIT LOAD CARRIER AND A
METHOD FOR MANIPULATING A UNIT LOAD
Field Of The Invention:
The present invention relates to the manipllla-
tion of a uni~ load and, in particular, to the ship-
ping, positioning, and lowering of a unit load.
8ackground Of The Invention:
A ~unit load" may be defined as a single item,
e.g., a piece of equipment, such as an offset dupli-
cating machine, or a collection or i~ems, e.g., a
rack of glass panes, that is to be moved from one
location to another. Frequently, the uni~ load is
bo~h heavy and fragiLe.
Manipulating a uni~ load, e.g., the piece of
equipment, may include shipping the equipment to a
particular destination, positioning it in a desired
location, and lowering it to a ~oundation surface,
such as the ground, a floor, a platform, or the
like, Considerable care is required to avoid damageto either the equipment or the people manipulating
the equipment. A blow to the equipment can cause
structural damage or upset delicate ~actory set-
tings. Dropping the equipment may not only similarly
damage the equipment but may also endanger people
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close to the equipment.
Conventional devices for manipulating a unit
load have several drawbacks. For example, U. S.
Patent 4,079,907 discloses a cushioned shipping sup-
port which includes a bumper-skid having a wedge-
shaped portion. Similarly, U. S. Patent 3,602,376
discloses a self-unloading skid having corner feet
with an inclined slip plane. In each of these con-
ventional devices, the unit load is shipped while
resting on the skid and then lowered into position by
sliding the unit load down the incline of the skid.
However, the rate at which the unit load slides
off the skid is frequently not accurately predictable
because it depends on a number of in~er-related fac-
tors including the angle of the incline, the amountof friction between the skid and the equipment, and
the weight of the unit load. For example, if the
skid becomes wet during shipping, the unit load may
slide down the incline at an excessive rate because
the friction between the skid and the unit load may
be greatly reduced if the incllne is wet.
Summary Of The Invention:
The invention provides an improved unit load
carrier and an improved method for manipulating a
unit load which allow the unit load to be gently and
safely lowered onto a foundativn surface at a con-
trolled rate.
In accordance with one aspect of the invention,
a unit load carrier may comprise a support for sup-
porting at least a portion of the weight of the unit
load and a fluid cell arranged adjacent to the sup-
port. The cell has collapsible walls and contains a
fluid, preferably a gas. The carrier further com-
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prises a mechanism for controlling the rate at which
the fluid i5 released from the cell.
With the weight of the unit load bearing on the
support, the unit load may be positioned in a desired
location The weight of the unit load may then be
transferred from the support onto the adjacent fluid
cell, forcing the fluid from the cell. As the fluid
is released, the walls of the cell collapse, lowering
the unit load onto the foundation surface. However,
the control mechanism limits the rate at which the
fluid is released and, therefore, the rate at which
the cell collapses, allowing the unit load to be
lowered at a cont~lled rate.
In accordance with another aspect of ~he inven-
tion, a unit load carrier may comprise two resilientcushions, a base arrangement, collapsible fluid
cells, and a mechanism for controlling the rate at
which fluid is released rom the cells. The resili-
ent cushions, each o~ which has upper and lower sides
and an edge extending between the sides, are arranged
with the edge of one cushion facing the edge of the
other cushion. The base arrangement is releasably
mounted to the cushions and supports the unit load on
the cushions. The collapsible fluid cells are mount-
ed to the edge of each resilient cushion.
With the unit load mounted on the base arrange-
ment and the base arrangement mounted on the resili-
ent cushions, the unit load then may be shipped to a
particular destination and positioned in a desired
location. The resilient cushions absorb the shock of
any blows to the unit load during shipping or posi-
tioning. Once the unit load is in position, the base
arrangement is released from the resilient cushions
and trancferred from the resilient cushions onto the
adjacent collapsible fluid cells, ~orcing the fluid
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from the cells. Again, the control mechanism limits
the rate at which the fluid is released from the
cells and, therefore, the rate at which the cells
collapse, allowing the unit load to be lowered to thP
foundation surface at a suitable rate. After the
cell has collapsed under the weight o~ the unit load,
the supports and base arrangement may be removed from
under the unit load.
Thus, in accordance with a further aspect of the
invention, a method for manipulating a unit load may
comprise the step~ of positioning the unit load on a
foundation surface with a support disposed between
the unit load and the ~oundation surface, trans~er-
ring the weight o~ the unit load from the support
onto a collapsible ~luid cell, and controlling the
rate at which fluid i9 released from the collapsible
cell to control the rate at which the unit load is
lowered to the foundation surface.
In one exemplary embodiment, the ~luid cell
comprises a cell containing air and the controlling
mechanism compri~es an orifice in the cell. The
orifice i5 sized to limit the rate at which air is
released from the cell. For example, the orifice may
comprise a small hole which only allows the air to be
2~ released slowly even with a heavy unit load resting
on the cell. As th~ air slowly escapes from the
cell, the cell slowly collapses and gently lowers the
unit load onto the ~oundation sur~ace.
The present invention not only allow~ the unit
load to be gently lowered into position and, there-
~ora, prevents damage to the unit load, but it also
reduces the risk of injury to workers mani~ulating
the unit load. It i~ the collapsing cell, not the
workers, which bears the weight of the unit load as
~5 it is being lowered onto the ~oundation sur~ace.
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Further, since the cell collapses slowly, the workers
do not need to independently support the weight of
the unit load and have ample time to ensure th~t
their hands and feet are not under the slowly. des-
cending unit load. Consequently, ~he risk of muscle
or back strain and the risk o~ injury to hands and
feet are greatly eeduced.
8rief DescriPtion Of The Drawings:
In the accompanying drawings:
Figure 1 is an exploded perspective view of a
first exemplary unit load carrier embodying the in-
vention;
Figure 2 is a perspective view of the support
and the fluid cells of the first exemplary unit load
carrier of Figure l;
Figure 3 is a plan view of a portion of the
first exemplary unit load carrier of Figure l;
Figure 4 is a sectional elevation view of the
first exemplary unit load carrier as viewed along
line 4-4 of Figure 3;
Figure 5 is a sectional elevation view of the
first exemplary unit load carrier as viewed along
line 5-5 of Figure 3 and
Figure 6 is a perspective view of a second exem-
plary unit load carrier embodying the present inven-
tion.
Detailed Description Of Exemplary Embodiments:
As shown in Figure 1, a first exemplary unit
load carrier 100 embodyin9 the invention generally
comprises two supports 101 releasably mounted to a
base arrangement 102 which, in turn, supports a unit
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load, such as a piece of equipment 10, on the sup-
ports lol. In accordance with one aspect of the
invention, the first exemplary unit load carrier 100
further comprises collapsible fluid cells 103 arrang-
ed adjacent to each support 101 and a fluid control
mechanism 104 for controlling the rate at which fluid
is released from the collapsible cells 103. The
supports lO1 serve to protect the equipment 10, for
example, during shipping and positioning, while the
collapsible cells 103 and the fluid control mechanism
104 allow the equipment 10 to ba lowered onto a foun-
dation sur~ace 11, such as the ground or a floor.
The supports 101 of the first exemplary unit
load carrier 100 are intended to support identical,
opposite edges 12, 13 of a relatively ~ragile but
heavy piece of equipment ~0, a.g., an offset dupli-
cating machine. Accordingly, the supports loo are
identical and are preferably constructed as resilient
cushions. For other unit load~, such as those not
having identical edges or those which are le5s
fragile, the supports 101 need not be identical and
may alternatively compri~e any suitable construction,
including a simple platform fashioned from wood,
metal, or a thermoplastic material.
Each resilient cushion may have any suitable
construction. For example, it may be fashioned from
a solid piece of resilient material, such as rub-
ber. As shown in Figures 2-5, in the first exemplary
unit load carrier 100, the resilient cushion i pref-
erably fashioned as a hollow ~hell 105 from a thermo-
plastic material, e.g., by blow-molding a low-
density, linear p~lyethylene. The hollow shell 105
defines an enclosed, generally air-tight cavity
106. Together, the hollow shell 105 and enclosed
cavity 106 provide a cushioning e~fect which resill-
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ently absorbs shock without significant permanent
deformation.
The hollow shell 105 is preferably configured
with an elongated body 110 and opposing brackets
111. The body 110 may include upper and lower sides
112C 113 and opposite ends 114, 115 and an inside
edge 116 which extend between the upper and lower
sides 112, 113. The upper side 112 may include sepa-
rated surfaces 120 for supporting the weight of the
equipment 10. To provide additional structural sup-
port, the body 110 may also include one or more
braces 121 disposed within the shell 105 and extend-
ing between the upper and lower 6ide~ 112, 113 near
the supporting surfaces 120. To ~tably ~upport thQ
equipment 10, the lower side 113 may be flak, as
shown in Figures 4 and 5, or may include several
feet.
The brackets 111 are mounted to the end~ 114,
115 of the body 110 and extend beyond the edge 116.
In the first exemplary unit load carrier 100, the
brackets are integrally formed with the body 110.
The bracket~ 111 preferably have a generally L-shaped
cross-section with one arm 122 extendlng parallel to
the upper side 112 of the bod~ 110 and the other arm
: 25 123 extending toward the lower side 113 of the body
110. The parallel arm 122 may include at least one
opening 124 for mounting the base arrangement 102 to
tha support 101.
The base arrangement 102 of the first exemplary
unit load carrier 100 comprises two runners 125 which
extend between a supporting surface 120 on one sup-
port 101 and a supporting surface 120 on the other
support 101, the edges 116 of the supports 101 facing
each other. Raised ends 114, 115 and raised ribs 126
on the upper ~ide 112 of each support 101 serve to
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position the ends o~ the runners 125 on the support-
ing surfaces 120. Further, a notch 130 at each end
of the runner 125 cooperates with a stop 131 on each
support 101 to limit the travel of the runners 125
along the supporting surfaces 120. One set of open-
ings 132 in the runners 125 are aligned with the
openinqs 124 in the arms 122 of the brackets 111 when
the runners 125 are properly positioned on the sup-
ports 101. ~eleasable connectors, such as nuts 133
and bolts 134, may be used to releasably mount the
base arrangement 102 to ~he supports 101. The equip-
ment 10, in turn, may be releasably mounted to the
base arrangement 102 by means of a second set of
openings 135 and releasable connectors, such as nuts
lS 136 and bolts 137, with the feet 14 of the equipment
10 hanging below the base arrangement 102.
Various alternatives to the base arrangement 102
of the first exemplary unit load carrier 100 may be
suitable. For example, as shown in Figure 6, a sec-
ond exemplary unit load carrier 200, which is identi-
cal to the first exemplary unit load carrier 100
except for the base arrangement 202, includes a base
arrangement 202 havinq runners 225 which do not ex-
tend from one support 201 to another. While the
runners 225 are releasably mounted to the equipment
(not shown), again by means of a second set of open-
ings 235 and releasable connectors (not shown), each
runner 225 is mounted to a single support 201 by
means of a first set of openings (not shown) and
releasable connectors 233, 234.
Further, some equipment may be suitable for
mounting directly to the supports. The base areange-
ment may then be entirely eliminated.
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The first exemplary unit load carrier 100 fur-
ther comprises two fluid cells 103, each spaced from
the support 101 but formed integrally with the edge
116 of the support 101 adjacent to a supporting sur-
face 120. Alternatively, a single fluid cell extend-
ing adjacent to both supporting surfaces could be
mounted to the edge, or the cells could be fixedly
mounted to the edge by a connector or by an adhe-
sive. The cells could also he removably mounted to
the support. Removably mounting the cells to the
support would allow the support to be reused since
collapsed cells could be replaced by new cells.
Further, the cells could even be incorporated in the
body of the support if the weight of the equipment
rested on the support during shipping or positioning
- and the cells remained free to be selectively col-
lapsed under the weight of the equipment.
Each fluid cell 103 preferably has an elongate
pillow-shaped configuration, is mounted genQrally
parallel to the body llO of the support 101, and
includes upper and lower side~ 140, 141 which respec-
tively lie generally in the planes of the upper and
lower sides 112, 113 of the support 101. Some pieces
of equipment have a support pedestal (not shown) so
the upper side 140 of each cell 103 may include a
depre3sion 142 for receiving the ~upport ped~tal.
Each fluid cell 103 ~urther include~ a collapsible
wall 143 which extends between the upper and lower
sides 140, 141. Together, the upper and lower sides
140, 141 and the collapsible wall 143 define an im-
pervious container for the ~luid. The fluid cells
103 of the first exemplary unit load carrier 100
preferably contain a gas, such as air, and the air
cell i~ preferably isolated from the air-tight cavity
106 of the support 101.
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The mechanism 104 for controlling the rate at
which Eluid is released from the cell 103 also may be
variously configured. ~or example~ it could comprise
a manually actuated valve assembly interconnecting
one or both cells to ambient pressure. In the first
exemplary unit load carrier 100, the fluid control~
ling mechanism 104 comprises an ori~ice sized to
limit the rate at which air is released from the cell
103. The size of the orifice 10~ may be determined
empirically or in accordance with standard engineer-
ing principles for any given fluid, material of con-
struction, cell volume, equipment weight, and desired
length of time for collapse. The orifice 104 is
preferably disposed in the collapsible wall 1~3 near
the lower side 141 of the cell 103 to minimize the
risk that the orifice 104 will become blocked as the
cell 103 collapse3.
In accordance with another aspect o~ ths inven-
tion, an exemplary method for manipulating a unit
load, e.g., a piece of equipment, generally comprises
positioning the equipment on a support resting on a
~oundation ~urface 11, such as the ground or a floor,
transferring the weight of the equipment from the
support onto a collapsible fluid cell, and control-
ling the rate at which the fluid is released from the
cell to control the rate at which the equipment is
lowered to the foundation surfaoe 11.
For example, the base arrangement 102 of the
first exemplary unit load carrier 100 may be mounted
to the supports 101 while the equipment 10 may be
mounted to the base arrangement 102. The equipment
10 along with the first exemplary unit load carrier
100 may then be shipped to any particular location
and positioned in a desired location with the first
exemplary unit load carrier 100 resting on the foun-
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dation surface 11.
Thus, during shipping and positioning, the sup-
port surfaces 120 of the supports 101 bear the weight
of the equipment 10. Further, the supports 101 are
dimensioned to extend beyond the sides of the equip-
ment 10 and below the bottom of the equipment 10.
Consequently, any jarring or blo ~ from adjacent
items will be absorbed and dissipatsd by the resili-
ent cushion, preventing damage during shipping and
positioning of the equipment.
Once the equipment has been positioned, the
re~ovable connectors 133, 134 mounting the base ar-
rangement 102 to the supports 101 may be removed.
The ends of the runners 125 are then slid off the
supporting surfaces 120 of one of the supports 101
and onto the pair of collapsible fluid cells 103
adjacent to the suppoxt 101, for example, by sliding
the support 101 relative to the base arrangement 102
and the foundation surface 11. This trans~ers the
weight of the equipment 10 from the support 101 to
the collap~ible Pluid cell~ 103. The weight oP
equipment 10 forces the air from the ~luid cells 103
through the orifice 104, resulting in a controlled
lowering of the feet 14 on one edge 12 of the equip-
ment 10 to the foundation surface 11. The other ends
of the runners 125 are then slid off the supporting
surfaces 120 of the other ~upport 101 and onto the
collapsible cells 103. Again, the weight of the
equipment 10 forces the alr from the fluid cells 103
through the orifice 104, resulting in a controlled
lowering of the feet 14 on the other edge 13 of the
equipment 10 to the foundation surface 11. With the
feet 14 of the equipment 10 resting on the foundation
surface 11, there is sufficient space between the
foundation surfaca 11 and the bottom oP the equipment
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10 to allow the collapsed cells 103 to be pulled from
underneath the edges 12, 13 of the equipment 10. The
base arrangement 102 is then removed from the equip-
ment 10 by means of the releasable connectors 136,
137.
The orifices 104 may be sized to provide a suit-
able length of ~ime for collapse. For example, it
has been predicted that a machine weighing approxi~
mately 860 pounds could be lowered about three inches
to the floor in app~oximately five seconds by four
air cells, each cell having a volume of approximately
thirty-five cubic inches, a linear polyethylene wall
with a thickness of approximately three/thirty-
seconds of an inch, and an orifice one/eighth of an
inch in diame~er.
While the invention has been described in terms
of several embodiments, it is not limited to those
embodiments. Alternative embodiments and modifica-
tions which would still be encompassed by the inven-
tion may be made by those skilled in the art, parti-
cularly in light of the foregoing teachings. There-
fore, the following claims are intended to cover any
alternative embodiments, modifications, or equiva-
lents which may be included within the spirit and
scope of the invention.
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