Note: Descriptions are shown in the official language in which they were submitted.
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FIELD OF THE INVENTION
This invention relates generally to handling of stacked
articles or material and more particularly concern a device
for vertical separation of stacked articles or materials for
insertion or withdrawal of the arms of a lifting device.
BACKGROUND OF THE INVENTION
Often articles or materials are stored or shipped by
stacking them one on top of the other with only a thin dingy
or wooden stickers providing spacing there between. Common
examples of such articles or materials are lumber, plywood,
cardboard, or other unpalletized building materials, pieces of
which are stacked for drying, storage or transportation and are
vertically Separated by wooden stickers which are approximately
1 inch or less thick. These tickers are usually placed about
1 to 1-1/2 feet apart along the length of the-materials. The
provision of the tickers allows for air circulation and ties
the load together. however, piles of such materials stacked on
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this manner, often weigh substantially more than the capacity
of a standard forklift, and the entire pile cannot be moved at
once. In audition, the piles of materials may be loaded onto
vehicles at one facility with a forklift of a capacity
sufficiently great to handle the entire stack while they are
unloaded at another facility by a forklift having a lesser
capacity. Most forklifts, especially those having capacities
adequate to lift a stack of undried lumber, have fork arms
which have a vertical thickness greater than the l-inch
thickness of the stickers. As a result, the entire load must
be lifted at once by the forklift or the pile must be loaded by
hand. In the past, in order to overcome the above problems,
bolsters or other large dingy have been placed under the
bottom layer of lumber or other building materials, or at
appropriate points between the layers. These bolsters are
normally 4-inch by 4-inch by 5-foot long timbers and are
expensive and difficult to handle. In addition, the placement
of these bolsters severely reduces the amount of lumber or
building materials which may be stacked in a given height, thus
restricting the capacity of the kiln or facility where the
material is stored.
:
Another commonly used solution to the above problem is to
place the lumber or other building materials or the stacked
articles on pallets. However, most conventional pallets which
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can be unloaded by a conventional forklift must have strong
supporting stringers in order to carry the desired load and
provide the 3- to 4-inch clearance beneath the load necessary
for fork entry, and the cost of such pallets is often too high
to justify shipping it with the materials. In addition, the
pallets must be stored with the goods, requiring additional
storage space and significantly increasing storage costs. This
cost problem in poulticed materials is often overcome by the
use of disposable pallets without tickers or stringers
necessary to provide the desired clearance and which may be
former of correlated materials An example of such pallets is
described in US. Patents 2,302,137 and 2,328/397. The forks
of a forklift must be wedged beneath such a pallet to lift it,
and a lift with special chisel forks must be used, or in some
cases, the pallet must be pulled onto the fork arms using a
special load-pulling device. This chiseling often damages the
goods and the load-pulling device requires the use of a very
high sheer strength corrugated material which is quite
expensive
.
Inflatable pallets, such as those described in US. Patents
3,440,976; 3,790,010; 3,913,964 and 4,116,344 may overcome some
of the above problems with poulticed materials. However, such
pallets must still be left with the load during shipping or
until the article is used, and these pallets tend to be
expensive, increasing handling and storage costs.
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SUP AWRY OF THE INVENTION
.
According to the invention, an inexpensive, easy-to-use
apparatus is disclosed for providing the required separation
between tacked material or articles for the insertion of the
arms of 8 forklift. This invention obviates the requirement
for storing loads on pallets or bolsters in order to provide
sufficient separation for the fork arms. With this invention,
layers of stacked materials or articles need only be separated
by one-inch high or less stickers or other dingy placed
there between. This invention also obviates fork arms which are
designed to be wedged between the layers of stacked articles or
materials for separation thereof and avoids the damage and
problems normally produced thereby.
This invention includes an elongated, inflatable bladder
which is relatively rigid in the direction of elongation. In
one embodiment rigidity is provided by a skid to which the
bladder is secured. In its uninflated condition, the bladder
and skid together typically are no higher than 3/4-inch, which
is less than the thickness of a typical sticker. A valve is
provided for inflation of the bladder, and an aspirator and
another valve are provided for deflation of the bladder. When
the bladder is inflated, it ha a vertical dimension greater - --
than the thickness of typical forklift arms. Stacked materials --
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or articles placed thereon are raised a similar distance.
Elastic straps tension the bladder in the direction of
elongation to collapse it to the desired height and to secure
it to the skid. The straps have sufficient elasticity to allow
inflation of the bladder while tensioning the bladder and
retaining the bladder in a fully extended position on the skid.
In another preferred embodiment, rigidity is provided to
the bladder by a metal framework which surrounds the bladder on
its sides but which does not extend above or below the bladder
where it contacts the stacked materials. The bladder is
stretched between portions of the metal framework to maintain
the desired configuration. In this other embodiment, because
; there is no skid, the total thickness of the apparatus in its
deflated condition is equal to the thickness of the metal
framework which is about 3/B-inch.
Ion use, the bladder is inserted between two stacked
particles or materials in tube space provided by the stickers,
and the bladder is inflated. The fork arms may then be
inserted between the articles or layers of material for lifting
and moving of the materials or articles. When the operation
has been completed, the bladder is deflated and recovered for
use elsewhere. Either two apparatus or one apparatus and a
bolster may be used for this purpose.
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This apparatus can also be used for off loading materials or
articles onto stacks thereof or onto a level surface without
the need of pallets. In this instance, the bladder along with
tickers are placed on the surface upon which the materials or
articles are to be located. The bladder is then inflated to
. . .
its desired height, and the articles or materials are placed
thereon by the forklift. The fork arms are withdrawn in the
space provided by the inflated ladder, and the bladder is then
deflated, allowing the materials or articles to come to rest on
the stickers. Thereafter, the apparatus may be removed for use
elsewhere. This same result can be achieved by using a single
apparatus in conjunction with a movable bolster. Thus, either
a single apparatus or one pair of this apparatus can be used
for off loading or unloading a large quantity of material, and
they need not be left with the materials thereafter as is the
case with pallets.
DESCRIPTION OF THE DRAWINGS -
The objects, advantages and features of this invention will
be more clearly appreciated from the following detailed
description taken in conjunction with the accompanying in which:
Fig. 1 is a pictorial view of one embodiment of the
apparatus of this invention in an inflated condition;
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Fig. 2 is a top view of the apparatus of Fig. l;
Fig. 3 is a cross-sectional side view of the apparatus of
Fig. is
.
Fig. 4 is a cross-sectional view of the apparatus of Fig. 1
in an inflated condition;
.
L - Figs. 5, 6 and 7 illustrate the use ox the apparatus do
this invention in one application;
Fig. 8 is a pictorial view of another embodiment of the
apparatus of this invention in an inflated condition; and
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Fig. 9 is a cross-sectional view of the apparatus of Fig. 8
in a deflated condition.
t DETAILED DESCRIPTION OF IRE PREFERRED EMBODIMENTS
' - With reference to the drawing and more particularly, to - :-
Figs. 1 through 4 thereof, apparatus 10, which represents one
embodiment of this invention, includes an inflatable bladder 14
elongated in one direction and resting on a skid 12. Bladder
14 is typically secured to one end of kid 12 by adjustable
nonelastic traps 16 and to the opposite end of skid 12 by
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elastic strap 18. Bladder 14 is sealed at each end, typically
by plates 20 which are bolted together. An inflation valve 24,
a deflation valve 26 and an aspirator 28 are provided at one
end of bladder 14.
Straps 16 and 18 are secured to plates 20 typically either
by bolts or by slots 22. Straps 16 and 18 insure that bladder
14 is tightly stretched between the two ends of skid 12 to
collapse it down to the required height when deflated and to
maintain it in a desired orientation, whether it is deflated as
shown in Fig. 3 or inflated as shown in Fig. 4. Strap 18 is
sufficiently elastic to permit the longitudinal shrinkage and
vertical movement that occurs as bladder 14 is inflated and to
still maintain the desired tension on the bladder when deflated
so that it is tightly stretched on skid 12 and does not have
portions thereof that extend above the desired height. Strap
16 has a buckle 11 for adjustment of the tension on bladder 14.
- .. . ..
In its uninflated condition, bladder 14 and skid 12
- together have a vertical height no greater than 3/4-inch which
to less than the one inch thickness of a typical sticker,
excluding the height of inflation valve 24, deflation valve 26
and aspirator 28. Typically, the vertical height of the
apparatus 10 when bladder 14 is deflated is about one-half
inch. When inflated, bladder 14 and skid 12 together must have
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a vertical height at least equal to the thickness of a typical
forklift arm, typically about 3 to 5 inches. The inflation
valve, the deflation valve and the aspirator usually are not
placed in the narrow space between the stacked articles or
materials, but extend beyond the stacked articles or material
for easy access thereto during operation of the apparatus.
Therefore they are not subject to the height restrictions
imposed on the remainder of the apparatus.
: . .
Skid 12 of this invention typically is flat, and
-rectangularly shaped and possesses sufficient rigidity to
prevent it from buckling under the stresses caused by inflation
of the bladder. The skid provides a structure sufficiently
rigid to be manually pushed into the 3/4- to l-inch high space
between stickers, spaces or other dingy. The skid may be
composed of metal, wood or any other suitable material. Skid
12 preferably is formed of l/B-inch sheet metal and the
required rigidity is provided by one-half-inch high side walls
19 which extend the length of the skid. Walls 19 may be formed
of 1/8 inch sheet metal which has been folded over onto itself
or of any other material that provides the desired rigidity.
Walls 17 may also be provided on either lateral side of skid 12
adjacent inflation valve 24, deflation valve 26 and aspirator
28 for protection thereof. Walls 17 extend from the end
adjacent the valves toward the opposite end of the skid to the
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point where the valves enter the bladder. Walls 17 typically
have a height generally equal to the height of the valves above
the bottom of the skid. Vertical surfaces 29 of walls 17 act
as stops which engage the projecting edge of the stacked
articles or materials to protect the valves. A handle 15 may
be provided on each lateral side of the skid on the end thereof
adjacent the valves. Handles 15 permit easy manual handling
and insertion and withdrawal of the skid from the stacked
articles or materials. A typical skid length is to D go
inches and a typical skid width is 7 to 10 inches. A typical
72-inch skid together with the bladder weighs about 30 pounds.
tune end of skid 12 adjacent straps 16 may be provided with a
slight upward or angular tilt, as shown in Fig. 3 to facilitate
entry of skid 12 into the narrow vertical space between the
articles provided by the stickers or dingy. Also, this
upward tilt insures that bladder 14 inflates evenly along its
length without deformation at its ends by applying a nearly
horizontal tension to the bladder. This upward tilt is very
small, and the thickness of wall 19 tapers as it nears the
tilted end of the skid so that the top of wall 19 never is
higher than one-half inch above the surface upon which the skid
rests.
.
Although skid 12 is shown disposed below bladder 14, it
could also be placed above bladder 12 and could be provided
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with longitudinally extending vertical support walls to provide
greater strength thereto. In addition, two skids may be used,
one disposed above the bladder and one disposed below to
capture the bladder there between for protection thereof.
Bladder 14 may be wormed of either an elastic material or a
nonelastic material. In either event, it must be capable of
being compressed into a small vertical thickness when deflated
and be capable of expanding to a vertical height at least equal
to the thickness of a fork arm when inflated. If the bladder
is not formed of an elastic material, it preferably folds when
deflated into a bundle having the desired height and a width no
greater than that of the skid, as shown in Fig. 2. Bladder 14
also may be formed from a woven fabric surrounding an elastic
interior bladder, the interlocking fibers providing the
necessary expansion when inflated. Bladder 14 is preferably
cylindrical when inflated, although it may also be oval,
rectangular or triangular in cross-section. Typically, the
bladder has a 4- or 5-inch diameter when inflated, and a
3/B-inch thickness when deflated, and it is capable of
withstanding pressures of 200 psi or more .
The inflation valve it a one-way valve, such a a
conventional tire valve, which closes when gas pressure is not
applied thereto from an external source, while the deflation
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valve may be a peacock. The aspirator provides means for
evacuating toe bladder to allow it to lie flat and to prevent
trapping of air therein. Typically, compressed air it used for
inflation of the bladder although other gases or liquids may be
used. In addition, a single two-way valve may be used for
inflation and deflation instead of the dual valves illustrated
herein.
An alternative preferred embodiment of the apparatus of
this invention will now be described with reference to Figs. 8
and 9. This embodiment is particularly suitable when the
thickness of the stickers or spacers separating the stacked
materials is less than one inch or where the upper and lower
surfaces of the materials are uneven 60 that even though the
stickers or spacers are one-inch thick, there is not a uniform
one-inch spacing between the tacked materials. The apparatus
of Figs. 8 and 9 also is portable like the apparatus of Figs.
. .
t--- 1-4, and it also has sufficient Roget to allow it to be pushed
into narrow spaces between stacked materials, but it is much
;~~ lighter in weight and has a much thinner dimension when
defoliated
Apparatus 80 of Figs. 8 and 9 includes an elongated
inflatable bladder 84, a generally planar frame 82 which
surrounds the bladder laterally on three tides and a handle
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I Frame 82 does not at any point extend over the top or
bottom of ladder 84 so that it does not come between the ;
bladder and the stacked materials. Frame 82 is typically
composed of a length of stainless steel rod, preferably ~-~~~-
3/8-inch in diameter. This length of rod is bent twice into
the desired rectangular shape to form wide portions 90 and end
portion 88. Bladder 84 is stretched in its direction of
elongation between handle 85 and end portion 88. Tune ends of
side portions 90 of frame 82 are each anchored into handle 85.
Typically side portions 90 each pass through a hole handle 85
and a bolt 92 passes through the intersection of each end of
side portion 90 and handle 85 perpendicular the plane defined
. . _ .
thereby for securing each side portion 90 to handle 85.
Bladder 84 may be identical in most respects to bladder 14
and need not be further described. Bladder 84 is sealed at
each end, typically by confronting, parallel plates 100 which
are clamped together to capture the ends of bladder 14
there between. Screws 103 may be used to clamp plates 100
together and they are recessed in one plate and thread ably
engaged mating holes in the other plate. In this manner, the
thickness of the plates is minimized. Bladder 84 is secured at
one end to end portion 88 by means of folded metal strips 86
which wrap around end portion 88 at spaced locations. The ends
of strips 86 are captured between plates 100 by associated
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screws 87. sledder 84 it secured at its other end to handle 85
by eye bolts 98. The eye portions of bolt 98 are captured
between associated plates 100 by screws 105~ while the threaded
portions thereof pass through handle 85 and are secured thereto
by cooperatively threaded nuts disposed on either side of
handle 85. Tension on bladder 84 may be adjusted to the
desired level by rotation of nuts 99. In this embodiment,
there is no need to provide an elastic strap for maintaining
. .
i the tension on bladder 84, because when bladder 84 is inflated,
it expands equally about both sides of frame 82 so that there
is little or no longitudinal shrinkage or vertical movement of
'I bladder 84. Once eye bolts 98 and nuts 99 have been adjusted,
further adjustment of the tension is unlikely to be needed.
_
An inflation valve 94, a deflation valve 96 and an
aspirator 97 are a o provided and may be similar to the
- corresponding inflation valve 24, deflation valve 26 and
¦ aspirator 28 of the embodiment of Figs. 1-4.
.
This embodiment of FIGS. B and 9, when deflated, can be
compressed into a height of only 3/8-inch, which corresponds to
the diameter of the rods forming frame 82. This height, of
course, excludes inflation valve 94, deflation valve 96 and
aspirator 97 as well as handle 85 which is typically one inch
in diameter. Apparatus 80, in a deflated condition, typically
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weighs about 9 pounds for a 72-inch length. Apparatus 80 can
also be provided in the same lengths as apparatus 10. In this
manner apparatus 80 may be pushed into spaces between stacked
materials, such as lumber, where the separation is Jo more than
inch at points, and where the materials extend over a
length of up to seven feet. A five-foot long version of
apparatus 80 is cable of lifting up to 15,000 pounds to a
spacing of 4-5 inches. Apparatus 80 is sufficiently light to
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be fully portable, and handle 85 provides for ease of insertion
and retraction and carrying of the apparatus. Because of its
light weight, the apparatus may be pushed into high or
. . .
hard-to-reach spaces for use at any location.
With reference now to Figs. S, 6 and 7, use of the
apparatus 10 or 80 of this invention will be described.
Although Fits. 5-7 are described with particular reference to
the embodiment of Figs. 1-4, the embodiment of Figs. 8 and 9
. ...
i- can also be used and would be used in exactly the same manner
as described for the embodiment of Figs 1-4. A plurality of
stacked materials or articles 50, such as lumber and the like,
are illustrated in Fig. 5 resting on a lower support 52, such
as the floor. Each article 50 or each group of articles 50 is
- separated by a plurality of spaced, horizontal wooden stickers
or spacers 54 or the like arrayed along the horizontal extent
of the stacked articles. Apparatus 10 of this invention in it
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uninflated condition is pushed into the space between the
stacked articles created by the stickers 54, as shown in Fig.
5. Typically, two apparatus 10 are utilized, each spaced from --
the other a horizontal distance approximately equal to the
spacing between the fork arms of a forklift. The inflation
valve is then coupled to a source of compressed gas 56 for
__ inflation of the apparatus. During this period of time, the
deflation valve lo placed in a closed position to prevent
leakage there through. Both apparatus are then inflated, either
simultaneously or sequentially until the articles 50 above the
device are raised from the articles 50 below the apparatus the
L__. desired vertical distance. The inflation valve then closes to
retain the gas within bladder 14, and the source of compressed
gas is removed. A forklift 58 is then deployed, the arms 60 of
which are inserted into the vertical space created by the
apparatus for lifting the articles 50 as shown in Fig. 7. When
this procedure has been completed, the deflation valve is
-- -- . . . . . . ... _ .
opened and the bladder is deflated by the aspirator to the
condition shown in Fig. 1, and both apparatus are recovered.
Alternatively, only one apparatus may be used together with
a bolster having a height generally equal to or less than the
inflated height of apparatus to achieve the tame result. One
side of the tack is raised first using the apparatus as -----
described, after which the bolster is inserted into the space
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created. Thereafter, the apparatus is deflated, removed to the
opposite side of the tack and inserted and inflated. The
forklift is then deployed to lit the stack, as shown in Fig. 7.
Apparatus 10 may be used for off loading, merely by
reversing the steps of the above procedure. Thus, after
stickers or spacers 54 have been put in place on lower support
t -- 52 a pair of apparatus of this invention may be placed in a
horizontally spaced, parallel position on top of support 52 and
inflated as shown in Fig. 7. A forklift may then deposit
articles 50 on top thereof, after which the arms 60 of the
forklift 58 are withdrawn. Both apparatus are then deflated by
means of their deflation valves and aspirators until the
ladder no longer bears against the underside of articles 50
At this point, the bladder may be withdrawn from between
articles 50 and support 52. Alternatively, a single apparatus
in conjunction with a bolster may be used in place of two
! apparatus to off load a stack of articles or materials, in a
! manner similar to that described for unloading. A bolster is
! placed on support 52 and an apparatus is placed on support 52
in spaced relation thereto. The articles 50 are then deposited
on the bolster and apparatus, and the fork arms 60 are
withdrawn. Apparatus is then deflated, removed and inflated
adjacent the bolster. The bolster is removed and the apparatus
is deflated and withdrawn from between articles 50 and support
; 52.
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This invention is most advantageously used for stacking and
unstacking lumber which is separated vertically by stickers
which are approximately l-inch or less thick and 2-inches wide
and photo or photo long. Since an entire stack of lumber
- normally cannot be lifted at once by a forklift, this invention
... . .
may be used to separate and lift sections of the stacked lumber
as desired. The approximately 3/B-inch vertical dimension of
one embodiment of this invention, when deflated, permits it to
be used in most lumber stacking applications, as well as for
stacking other unpalletized materials such as plywood or
cardboard. The arms of a forklift need not be wedged between
the stacked materials, and thus damage thereto is prevented.
Permanent storage on pallets and bolsters is obviated,
permitting a greater amount of material to be stacked in a
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given vertical space. Storage costs are reduced because of the
greater amount stored in the available area and because
expensive pallets need not be stored with the goods. This
invention Allah permits loads resting on corrugated sheets which
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have been stapled to l-inch by 2-inch stickers to be removed
--._ . . .
¦- from the floors of trailers, railcard or storage areas with
non powered low lift hand trucks, a feature which is not possible
wit any existing material handling system. In addition,
because l-inch by 2-inch stickers can be used between each
article of a tack, many different items may be stored on top
of one another in the same stack without the need of pallets.
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The above description is exemplary, and modifications and
improvements are intended to fall within the scope of this
invention as defined solely in the following claims. - --
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