Note: Descriptions are shown in the official language in which they were submitted.
CA 02282285 1999-09-17
STORAGE SYSTEM
The present invention relates to a storage system for the storage of multiple
loads within a bay, and particularly to a storage system having rolling carts.
BACKGROUND OF THE INVENTION
Storage systems with rolling carts allow efficient storage of a plurality of
loads
within a storage bay. Such storage systems, commonly known as push-back cart
storage systems, are loaded and unloaded from a position at the front of the
storage
bay.
Conventional push-back cart storage systems, such as those described in U.S.
Patent 4,687,404, and U.S. Patent 4,773,546, utilize a single pair of tracks
within a
storage bay along which a plurality of wheeled carts move rearwardly as
successive
loads are stored thereon.
Push-back cart storage systems are known which allow two carts to roll along
either the inside or the outside edges of a pair of rails. U.S. Patent
5,393,188 teaches
a system which comprises three nested carts traversing a pair of rails. Two of
the
carts have wheels which roll along the same edge of a pair of rails, while a
third cart
travels along the opposing edge of the same rails. The wheels rolling along
the same
edge of the rail may collide as the carts are urged forwardly or rearwardly,
which
could result in derailment of one of the carts. Additionally, in this system,
the
uppermost cart, which receives the first load rolls along the inner edge of
the rails, and
must nest within successively wider carts at the front of the storage bay.
Lower carts
must be U-shaped to allow an upper cart to nest therein, and cannot have a
closed
load-bearing platform or even a rearward cross-beam. The U-shaped carts are
less
supportive of a heavy load, and thus increase the risk that a load will fall
from the
cart.
U.S. Patent 5,180,069 teaches a three cart storage system in which three
nested
carts roll along a single pair of I-shaped tracks. Two of the carts travel
along an upper
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surface of the track, and one of the carts travels along a lower groove formed
in the
track. However, the cart rolling along the groove cannot be lifted from the
track for
easy re-assembly or routine maintenance, but must be rolled off an end of the
track to
be removed from the system.
Two pairs of rails are employed in the three cart system described in U.S.
Patent 4,341,313 in which each cart rolls along a distinct edge of a pair of
rails,
thereby allowing storage of up to four loads. In this system, an upper cart is
not
prevented from passing forward of a lower cart.
There is a need for a storage system having storage capacity for five or more
successive loads which obviates or mitigates the above-noted deficiencies of
the prior
art.
SUMMARY OF THE INVENTION
According to the invention, there is provided a storage system comprising a
pair of primary rails having a front end and a back end, and at least one pair
of
auxiliary rails positioned between the primary pair of rails and parallel
thereto. Each
successive pair of auxiliary rails is positioned between the preceding pair of
said
auxiliary rails and is parallel thereto. The rails have an inner edge and an
outer edge.
Carts are provided which comprise a front end, a load-bearing surface and
wheels
adapted to roll on a pair of rails. The carts are of successively narrowing
widths and
are configured to internest with the widest cart being uppermost and
successively
narrower carts being nested therebeneath. The widest cart is adapted to roll
on the
outer edge of the pair of primary rails, while the next widest cart is adapted
to roll on
the inner edge of the pair of primary rails. Carts of successively decreasing
width are
adapted to roll on the outer edges and inner edges respectively of each
successive pair
of auxiliary rails.
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Advantageously, the inventive system allows for storage of five or more
successive loads within a storage bay, thereby optimizing storage space.
Additionally, only one cart rolls on any rail edge, thereby eliminating the
possibility
of collision between wheels from different carts along a rail edge. Because
each rail
is utilized by two carts, use of the rails is optimized.
The invention also provides a storage bay comprising the inventive storage
system arranged within a support frame. A storage unit is additionally
provided
which comprises a plurality of storage bays having the inventive storage
system
arranged therein.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the
following description in which reference is made to the appended drawings
wherein:
FIGURE 1 is a perspective view of the storage system according to an
embodiment
of the invention having carts nested at the front end of the rails;
FIGURE 2 is a perspective view of the embodiment according to Figure 1,
showing
the carts positioned along the entire length of the rails;
FIGURE 3A is a sectional view across lines A--A of Figure 1;
FIGURE 3B is a front view of the embodiment of Figure 1;
FIGURE 4 is a top view of the rails for the storage system depicted in Figure
1;
FIGURE 5 is a side view of the support frame for housing a storage system
according
to an embodiment of the invention;
FIGURE 6 is a front view of a storage unit according to an embodiment of the
invention; and
FIGURE 7 is a perspective view of a storage unit according to an embodiment of
the
invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention relates to a storage system having the capacity to store
five or more loads. The invention also relates to a storage bay having the
inventive
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storage system housed within a support frame and to a storage unit comprising
a
plurality of storage bays. With reference to Figures 1 to 7, the invention
will now be
described in further detail.
The embodiment described herein comprises a pair of primary rails, one pair
of auxiliary rails and four carts. However, it is possible to add more pairs
of auxiliary
rails which would run between and parallel to the first pair of auxiliary
rails. For each
pair of auxiliary rails used, one or two more carts may be added to the
system, thereby
increasing the load bearing capacity of the system.
In the embodiment depicted in Figures 1 to 3B, a pair of primary rails 10 and
a
pair of auxiliary rails 12 are provided. The storage system further comprises
carts 16,
18, 20 and 22. The rails are parallel to each other. As shown in Figures 3A
and 3B,
each rail has an outer edge 24 and an inner edge 26.
Each rail is configured to allow wheels to roll along both edges thereof, and
thus must be wide enough to permit passage of the wheels of a cart on both the
inner
edge and outer edge. As depicted in Figures 3A and 3B, the rails have a flat
upper
surface 28 on which a wheel 30 may travel. Any adequate rail type may be
employed,
provided that the wheels of a cart can roll along both edges. A rail may be
square or
rectangular in section, and may comprise individual beams placed in contact
with and
directly adjacent each other, for increased strength. For example, as shown in
Figures
3A and 3B, each of the auxiliary rails comprise two adjacent beams 32, 34
placed in
contact with each other.
As depicted in Figure 4, the pair of primary rails 10 comprise a front end 36
and a back end 38. The primary rails 10 may extend from the front to the back
of a
storage bay on a support frame. Such a support frame 40 is shown in side view
in
Figure 5. The pair of auxiliary rails 12 extends parallel to the pair of
primary rails 10
and is positioned therebetween. The pair of auxiliary rails 12 may extend the
full
length of the primary rails, or may be shorter than the pair of primary rails
by up to
CA 02282285 2002-02-28
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about the length ctf the two first carts 16, 18 which roll ~lo,~g the prirnarv
roils 10
only. if the auxiliary rails are shorter than the primary rails, the front end
of the
auxiliary rails is preferably aligned with the fi~ottt end 36 of the primary
rails, as
depicted in Figure 4. The pair c>fauxiliarv rails 12 nra5~ he of a slu~rter
length hecau~e
the first and second carts lfi, 18 roll along the primary rrtil~ only, while
flte third and
fourth carts 20, 22 roll along the pair of auxiliary rails 12 only. The third
arid .fourth
carts 20, 22 are only loaded once the ~trst and second carts 16, l8 hare been
loaded
and moved toward the back end 38 of the rails.
T'lte height of the auxiliary rails is inferior to the height «f the prinrrry
rails. In a preferred
embodiment, the height of the auxiliary rails is ab«crl half of that of the
primary rails.
For embodiments in which more than four carts are employed, snbsc:quent
pairs of auxiliary rails are disposed between the first pair of auxiliary
rails 12, and
may be shorter than the first set of auxiliary rails by the combined length of
the third
and fotrrlh carts, since only subsequent fifth mid ,r sixth carts would
tlaVCrse the
second set of auxiliary rails. ns with the first set of auxiliary rail,,
fi~rtlter sets of
auxiliary rails would be aligned at the front end 3fi of llte rails so I.h~t
all carts can be
internestecl prior to storing a Load thereon.
The carts are sized so that the cart 16 which beat's the first load is wider
than
the subsequent carts, identified as 18, 20 and 22 in T' figures I and :?.
('art ( l is
positioned vertically higher than the subsequent carts, so that other c,rrts
may fit
thereunder. Subsequent ~ ar s are successively narrower, so that they may be
internested when at the front. of the rails, as depicted in ~~igures 1 and 3A.
/\ wider
cart is higher in the nesting arrangement than a narrower cart, and thus wider
carts arr
loaded first according to the invention.
Fac;h cart ltas a load-hearing surface 42 wltl('h Cirlt SIrppOrt a Ic~ad. lrr
the
embodiment shown in higures I and 2, the load-bearing surface 42 is a
rectangular
frame. Any configuration supportive of a load could be used as the load--
bearing
surface. In the ernboditnent wherein the load-bearing surface is a rectangular
frame,
the sides of the frame which are parallel to the rails are spaced no fin-tltet
apart than
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the width of a typical load, so that the load may rest on the sides of the
frame when a
load is stored on a cart.
Optionally, according to an embodiment of the invention, one or more of the
carts 16, 18, 20, 22 may comprise a lip 44 at the front of the cart extending
upwardly
of the load-bearing surface. The lip of a narrower cart abuts the front of an
adjacent
wider cart when the carts are internested. For example, the abutment of the
lip 44 of
cart 22 with the adjacent wider cart 20 prevents rearward passage of narrower
cart 22
past adjacent wider cart 20.
The carts have wheels 30 disposed thereon for rolling on a pair of rails 10,
12.
Typically, a cart will have two wheels on each of two sides. Only one cart
rolls along
any given edge of a rail, which prevents collision of carts along the same
rail.
As depicted in Figures 3A and 3B, the wheels of the first cart 16 are in
rolling
engagement with the outer edge 24 of the pair of primary rails 10. The wheels
30 of
the second, narrower, cart 18 roll on the inner edge 26 of the pair of primary
rails 10.
The wheels 30 of the third cart roll on the outer edge 24 of the pair of
auxiliary rails
12. The wheels 30 of the fourth cart 22 are in rolling engagement with the
inner edge
26 of the pair of auxiliary rails 12.
The wheels of the carts may be formed in any suitable shape, and according to
an embodiment of the invention, may be a flanged wheel, having a flange 46 on
the
inboard side and facing the edge on which the wheel is rolling, as shown in
Figures
3A and 3B. This allows a cart to remain in the tracks while rolling on a flat
surface,
and reduces the amount of side to side motion, thus preventing derailment of a
cart.
The wheels may be made of metal. Any wheel configuration which would allow a
wheel to roll along an edge of a rail could be used with the invention.
Conveniently,
according to the embodiment depicting Figures 3A and 3B, carts may be lifted
from
the rails for cleaning or maintenance without requiring removal of the carts
from the
front end or back end of the rails.
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The rails incline downwardly toward the front end to urge the carts 16, 18,
20,
22 into the internested position at the front end of the rails, as depicted in
Figures 1,
3A and 3B.
The pair of primary rails 10 may be vertically higher than the pair of
auxiliary
rails, for example as depicted in Figures 3A and 3B. This serves to promote
internesting of the carts without requiring extreme variations in cart
heights. This also
allows a smaller distance between the wheels 30 and the load-bearing surface
42 of
wider carts, which improves stability. Additionally, the higher positioning of
the
primary rails 10, permits the fifth load to rest only on the pair of primary
rails 10,
since auxiliary rails 12 do not extend to the vertical height of the primary
rails.
The pair of primary rails 10 support the weight of three loads, including two
carts, while each pair of auxiliary rails 12 support the weight of two loads,
including
two carts.
According to an embodiment of the invention, a storage bay 48 is provided
which comprises a support frame 40 as depicted in Figures 6 and 7, on which
the
inventive storage system is supported. The storage system may comprise a
plurality
of bays 48 in a storage unit 50 as depicted in Figure 7. The support frame 40
may be
structurally common to one or more storage bays 48 of a storage unit 50.
Optionally, as shown in Figure 7 a first retainer member 52 may be situated at
the front end of the rails, for example adjacent the support frame 40 of the
storage
bay, to prevent the carts 16, 18, 20, 22 from leaving the rails from the front
of the
rails. As a further option, a second retainer member 54 may be provided at the
back
end of the rails to prevent the carts from leaving the rails from the back end
thereof.
The first and second retainer members may be of any suitable variety, such as
an L-
shaped bracket or a beam disposed in front of the internested carts to prevent
further
forward motion.
CA 02282285 2001-06-29
In operation, the number of loads which may be stored in a system is
calculated as the number of carts within a system plus one, since the final
load may be
stored directly on the primary pair of rails.
According to an embodiment of the invention, the rails are inclined
downwardly from the back end to the front end. When the system contains no
stored
load the carts are empty, and are urged toward the front end of the rails in
the
internested position. When the first load is deposited onto the widest cart
16, the first
cart 16 can be moved toward the back end of the rails. To load the second cart
18,
the second load is brought to the front end of the rails and is pushed against
the first
loaded cart, urging the first loaded cart rearwardly to reveal the narrower
cart 18
which is nested immediately therebeneath. This procedure is repeated for loads
to be
stored on the subsequently narrower carts 20, 22. The fifth load pushes all
four initial
loads back and is set down directly on the primary pair of rails 10. In the
reversal of
this procedure; as a load is removed from the front, all remaining loaded
carts move
toward the front end 36 of the rails, due to the forward inclination of the
rails.
Various modifications may be made without departing from the
invention. It is understood that the invention has been disclosed
herein in connection with certain examples and embodiments.
2~ However, such changes, modifications or equivalents as can be used
by those skilled in the art are intended to be included.
Accordingly, the disclosure is to be construed as exemplary, rather
than limiting, and such changes within the principles of the
invention as are obvious to one skilled in the art are intended to
be included within the scope of the claims.
