Note: Descriptions are shown in the official language in which they were submitted.
CA 0221~7~9 1997-09-18
TITr~T~ OF T~T~ T~VT~NTION: p~T T-~T STACKING AND DISPENSTNG UNIT
FIT~T~n OF THE INVENTION
The present invention relates to a pallet stacking and
dispensing apparatus.
BACKGROUND OF THE INVENTION
It is common practice to use pallets, usually made of
wood, to store or carry articles thereon. Most of the pallets
used, at least in the North American market, are of standard
size: 40" by 48" effective storing area, 5.5" thick, and they
each weigh approximately 100 pounds. These pallets are provided
with wide rectangular widthwise entries on their longer sides,
destined to be engaged either by the forks of a forklift truck,
or by the forks or deck of a manual pallet pushcart, for
carrying the pallets, especially when they are loaded with
articles. The shorter sides of the pallets are provided with
small half-moon shaped openings, that are destined to be engaged
by the forks of a forklift truck.
When the pallets are not loaded with articles, they
are usually stacked on the warehouse floor at a suitable
selected location. Usually, about ten pallets are stacked in
this manner, forming approximately a stack of six feet in
height. When a pallet is needed for carrying an article
thereon, the top pallet from a stack will be manually grabbed,
CA 0221~7~9 1997-09-18
preferably by a pair of persons, since trying to single-handedly
move the rather heavy pallets can bring about serious back
wounds to the work person accomplishing this task due to the
strenuous effort resulting therefrom. Thus, to move a single
pallet, the combined effort of two work persons is required.
While they are handling a pallet, the work persons are subjected
to several hazards from their task, namely extreme physical
strain resulting from a strenuous effort, especially back
wounds, or feet or leg wounds resulting from one of the workmen
dropping the pallet, wood splinters lodging themselves in the
hands of the workmen, or other wounds resulting from the pallet
handling operation.
Large automated pallet dispenser units are available,
for dispensing pallets at a regular rythm, these units being
particularly advantageous in industrial applications, where a
large number of pallets has to be regularly provided for
articles to be loaded thereon. These pallets dispenser units
are often combined with an article dispenser, for automatically
loading the articles on the pallets. However, these automated
pallet dispenser units require a very large area in a warehouse,
and are very expensive.
OBJ~CTS OF THE T~VENTION
It is the gist of this invention to provide a pallet
stacking and dispensing unit that may dispense or receive a
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pallet without requiring manual handling thereof.
It is an important object of this invention that the
pallet stacking and dispensing unit allow stacking of the
pallets over a small floor area.
It is another object of this invention that the said
pallet stacking and dispensing unit allow operation thereof by
a single work person.
It is yet another object of the present invention that
the pallet stacking and dispensing unit be as inexpensive as
possible.
SU~MA~Y OF THE INVENTION
The present invention is a pallet stacking and
dispensing unit, for vertically stacking a number of pallets
over ground, the stack of the type having a first lowermost
pallet and a second pallet located directly over the first
pallet, said unit comprising:
a) a frame for surrounding at least partially the stack of
pallets and thus for laterally at least partly supporting the
stack of pallets;
b) pallet engaging means mounted on said frame, vertically
movable therealong and horizontally movable relative to said
frame between an inner pallet engaging position and an outer
pallet clearing position, for selectively engaging a single
selected pallet in the stack of pallets among the first and the
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second pallet, in a stable fashion;
c) actuating means, for vertically moving said pallet
engaging means along said frame; and
d) power means, for powering at least said actuating
means;
wherein the stack of pallets above and including the selected
single pallet can be vertically moved upon the selected single
pallet being engaged by said pallet engaging means and upon said
actuating means accordingly vertically moving said pallet
engaging means along said frame, thereby allowing the first
pallet to be removed from the stack, or raised for insertion
under the stack of an additional pallet.
Preferably, said frame defines an inner housing
destined to receive said pallets and two opposite sides, said
pallet engaging means comprising a pair of fingers on each said
frame side destined to selectively engage opposite sides of the
selected single pallet.
Advantageously, said pallet engaging means further
comprises pivoting means for pivoting said fingers between a
pallet engaging position in which they project inside said
housing, and a pallet clearing position in which they are
located outside said housing, said stack of pallets above the
selected single pallet being vertically moved upon said fingers
being concurrently vertically moved by said actuating means,
when said fingers are in said pallet engaging position and when
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they engage the selected single pallet in said housing.
Preferably, said actuating means comprises a U-shaped
lever having two ends and an intermediate portion located
intermediate said two ends, said U-shaped lever being pivotally
mounted to said frame at said two ends, said actuating means
further comprising two carriage members each pivotally holding
a pair of said fingers, said two carriage members being rigidly
and hingedly attached to said U-shaped lever at said
intermediate portion thereof for vertical linear displacement of
said carriage members upon pivotal displacement of said U-shaped
lever.
Preferably, said power means comprises a first
electrically powered cylinder having a piston rod hingedly
attached to said U-shaped lever at said intermediate portion
thereof, for a corresponding pivotal displacement of said U-
shaped lever upon extraction or retraction of said piston rod,
said cylinder being either one of a hydraulic cylinder and a
pneumatic cylinder.
Preferably, said power means comprises a second and a
third electrically controlled cylinders having piston rods each
hingedly linked to one of said pair of fingers, for pivotal
displacement of said fingers between said pallet engaging
position and said pallet clearing position upon extraction and
retraction of said second and third cylinders, said second and
third cylinders being either one of a hydraulic cylinder and a
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pneumatic cylinder.
Preferably, said frame is generally U-shaped and
comprises two opposite side walls and a rear wall linking said
side walls, said side walls and said rear wall defining said
housing and being destined to receive the stack of pallets in
adjacent fashion therebetween, said actuating means being
located outside said housing, each said side wall defining a
lower portion and having at least one opening at its said lower
portion to allow passage therethrough of said fingers upon same
being pivoted by said pivoting means into said pallet engaging
position, and vertical displacement therein of said fingers upon
same being vertically displaced by said actuating means.
In a first embodiment, each said side wall lower
portion comprises two vertical slots each destined to be engaged
by one of said fingers.
Alternately, a second embodiment is disclosed in which
each said side wall lower portion opening is wider than one
pallet, said unit further comprising a rail member transversely
crossing said housing parallel to said rear wall and through
said wide openings, and a dispenser arm member movable along
said rail member from a retracted position to a dispensing
position located on one side and the other of said housing, said
dispenser arm member being destined to selectively laterally
push the first pallet out of said housing upon it moving from
its retracted to its extracted position, and upon said fingers
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engaging and upholding the second pallet and the stack of
pallets thereabove to remove the load from the first pallet.
In a third embodiment, said side wall lower portion
opening is at least as wide as one pallet, said unit further
5comprising conveying means located under said frame and
laterally extending beyond said one wide side wall lower portion
opening, wherein the first pallet can be conveyed out from under
the stack of pallets through said one wide side wall lower
portion opening by said conveying means upon said fingers
10engaging and upholding the second pallet and the stack of
pallets thereabove to remove the load from the first pallet.
Preferably, said unit further comprises marker means
for monitoring the vertical position of said pallet engaging
means relative to the stack of pallets.
15The present invention also includes a method for
inserting an additional pallet under a vertical stack of pallets
with a pallet stacking and dispensing unit, the stack of the
type having a lowermost pallet, said unit comprising:
- a frame wall partly surrounding said pallets;
20- pallet engaging means mounted adjacent said frame wall
and vertically movable therealong;
- actuating means, for vertically moving said pallet
engaging means along said frame;
- pivoting means, for pivoting said pallet engaging means
25between a pallet engaging position in which they project inside
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said frame wall and a pallet clearing position in which they are
located outside said frame wall; and
- power means, for powering said actuating means and said
pivoting means;
wherein said method comprises the following steps:
a) aligning said pallet engaging means with said lowermost
pallet;
b) activating said pivoting means for engagement of said
engaging means with said lowermost pallet;
c) activating said actuating means so as to raise said
engaging means and concurrently the stack of pallets over
ground, and support said stack of pallets over ground; and
d) inserting an additional pallet under the stack of
pallets.
The invention further discloses a method for removing
the lowermost pallet from under a vertical stack of pallets with
a pallet stacking and dispensing unit, the stack of the type
having the lowermost pallet and a second pallet located directly
above the lowermost pallet, said unit comprising:
- a frame wall partly surrounding said pallets;
- pallet engaging means mounted adjacent said frame wall
and vertically movable therealong;
- actuating means, for vertically moving said pallet
engaging means along said frame;
- pivoting means, for pivoting said pallet engaging means
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between a pallet engaging position in which they project inside
said frame wall and a pallet clearing position in which they are
located outside said frame wall; and
- power means, for powering said actuating means and said
pivoting means;
wherein said method comprises the following steps:
a) aligning said pallet engaging means with said second
pallet;
b) activating said pivoting means for engagement of said
pallet engaging means with said second pallet;
c) activating said actuating means so as to raise said
engaging means and concurrently the second pallet together with
the stack of pallets located above the second pallet over
ground, and support same over ground; and
d) removing the now unloaded lowermost pallet from under
the stack of pallets.
Generally, the present invention discloses a pallet
stacking and dispensing unit for stacking a number of pallets
over ground, comprising:
a) a frame for at least partially surrounding a stack of
pallets and substantially maintaining the latter in vertical
alignment;
b) pallet engaging means mounted on said frame, vertically
movable on opposite sides of said the stack and horizontally
movable relative thereto between an inner pallet engaging
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position and an outer pallet clearing position, for selectively
engaging any single selected pallet of the stack;
c) powered actuating means for vertically moving said
pallet engaging means along said frame; and
d) actuating means for horizontally moving said pallet
egaging means between said inner and outer positions
independently of said powered actuating means;
wherein any selected pallet and the pallets stacked over the
same can be raised by said unit for insertion or removal of at
least one pallet into or from the stack.
D~.~CRIPTION OF T~ DRAWINGS
In the annexed drawings:
Figure 1 is a perspective view of the stacking and
dispensing unit of the invention, with the U-shaped arm in
raised position and the pallet supporting fingers in pallet-
engaging position;
Figures 2 and 3 are partly broken perspective views,
at an enlarged scale, of the stacking and dispensing unit of the
invention, with the U-shaped arm in lowered position,
sequentially suggesting the outward pivotal movement of the
pallet support fingers from a pallet engaging position to a
pallet clearing position.
Figures 4 and 5 are schematic side elevations of the
stacking and dispensing unit of the invention, with the U-shaped
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arm in raised and lowered position, respectively;
Figures 6 to 8 are perspective views of the stacking
and dispensing unit of the invention, in which are stacked a
number of pallets, sequentially suggesting how a pallet may be
5added to the pallet stack;
Figures 9 to 11 are perspective views of a second
embodiment of a pallet stacking and dispensing unit according to
the invention, equipped with a first automatic dispenser device,
sequentially suggesting the dispensing of one pallet, with the
10pallet stack not being shown in figures 9 and 10 for clarity of
the drawings; and
Figure 12 is a perspective view of yet a third
embodiment of a pallet stacking and dispensing unit, with a
second automatic dispenser device comprising conveyor means
15being provided thereto.
D~TAILED D~CRIPTION OF THE p~ERR~n ~BODI~TS
Figures 1 to 8 show a first, preferred embodiment of
the invention.
20Referring more particularly to figures 1 to 5, and
according to the objects of the present invention, there is
disclosed a pallet stacking and dispensing unit 20 comprising a
U-shaped frame 22 having two opposite facing side walls 24, 26
and a rear wall 28 integrally linking side walls 24, 26. Frame
2522 thus defines a front opening 30, and is further opened at its
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lower end 32 and topped at its upper end by an integrally
attached overlying steel rod 34. Rear wall 28, as seen in
figure 1, can have a large vertical opening 28a therein. Side
walls 24, 26 have short, outturned flanges at their front
extremities, for an enhanced stability and structural integrity
of unit 20, the flanges helping the pallet alignment and
insertion into the pallet stacking unit 20 in the method that
will be explained hereinafter. Unit 20 is self-standing,
resting on the ground on the lower edges of walls 24, 26, 28.
Pallet unit 20 further comprises actuating means in
the form of a U-shaped lever 36 having two extremities 36a, 36a
pivotally anchored to the frame side walls 24, 26, respectively,
near front opening 30. Lever 36 defines an intermediate portion
between extremities 36a, 36a. One lever extremity 36a is not
shown in drawings, being hidden behind side wall 24. U-shaped
lever 36 horizontally straddles frame 22 on the exterior side
thereof, with its side arms being parallel to side walls 24, 26
and with its web parallel to rear wall 28.
The actuating means further comprises a pair of
identical carriage members 38, 38, with only one carriage member
38 being seen in the drawings since the other one is hidden
behind side wall 24. Each carriage member 38 is a substantially
rectangular flat sheet having integral perpendicular upper and
lower edges 38a, 38b (figures 2 and 3) for an enhanced rigidity
thereof. Carriage member 38 is vertically movable along
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vertical guide rails 40, 42 fixedly attached to side wall 26 (or
24 for the other carriage member 38), and is linked to the side
arm of lever 36 (thus at its intermediate portion), spaced from
pivoted extremity 36a by a rod 44 which is hingedly attached to
lever 36 at 46.
A permanent motionless visual mark 48 is inscribed on
the frame side wall 26 (though not on side wall 24), and a
movable visual mark 50 is fixedly installed on rod 44 and
vertically moves therewith.
As shown in figures 4 and 5, a first large cylinder 51
is provided adjacent rear wall 28, outside frame wall 22, though
fixed thereto. Large cylinder 51 is destined to rest on - and
be supported by - the ground, as seen in figures 4 and 5. The
piston rod 51a of cylinder 51 is hingedly attached to the web of
U-shaped lever 36, i.e. at the intermediate portion of lever 36.
Cylinder 51 can be either one of a hydraulic cylinder and a
pneumatic cylinder. By extracting or retracting cylinder 51,
pivotal movement of the U-shaped lever is acquired upwards or
downwards, respectively. Figures 4 and 5 sequentially show the
piston rod 51a in its extracted and retracted position, with the
lever 36 being downwardly pivoted accordingly from its upward
position in figure 4 to its downward position in figure 5.
Pallet engaging means are provided in the form of two
pairs of fingers 52, 54 and 56, 58 (figures 1 to 3) having a
flat upper surface. Fingers 52, 54, 56, 58 can project inside
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frame wall 22 through vertical slots 60, 62, 64, 66 correctly
sized therefor, slots 60, 62 being located on the lower portion
of side wall 24 and slots 64, 66 being located on the lower
portion of side wall 26.
Pivoting means allow fingers 52, 54, 56, 58 to pivot
in and out of slots 60, 62, 64, 66, i.e. from a pallet engaging
position in which they project inside their respective side wall
24, 26 through slots 60, 62, 64, 66, to a pallet clearing
position in which they are located outside the housing of frame
wall 22. The pivoting means, shown inter alia in figures 2 and
3 adjacent side wall 26, are identically provided on the other
side of side wall 24. The pivoting means include extensions 68,
70 integrally projecting upwardly from fingers 56, 58, and
fixedly installed on a horizontal pivot rod 72, which is in turn
pivotally mounted on carriage member 38. A rigid crossbar 74
also rigidly links fingers 56, 58 in a common pivotal movement.
A small L-shaped hinge member 76 has a lower cross pin which is
pivotable around the outer end pivot holes of a double plate 77
perpendicularly projecting away from the flat outer surface of
carriage member 38 and integrally fixed thereto, and is
downwardly limited in its pivotal displacement by its abutment
on a short transversely projecting edge plate 78 fixed on
carriage member 38, parallel to and intermediate upper and lower
edges 38a, 38b. The elbow of L-shaped hinge member 76 iS also
rigidly and pivotally linked by pivot 79 to crossbar 74. A
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cylinder 80 is hingedly attached to carriage member 38 at 82,
and its piston rod is hingedly attached at its outer end to L-
shaped hinge member 76, so as to pivotally rotate the latter
around its pivot 79. Cylinder 80 can be either one of a
hydraulic cylinder and a pneumatic cylinder.
As shown sequentially in figures 2 and 3, the
retraction of the piston rod of cylinder 80 rotates L-shaped
hinge member 76 around its lower pivot at 77 and pulls it
upwardly; pivot 79 moves outwardly and this results in an
outward pivotal movement of fingers 56, 58. Fingers 56, 58 are
thus movable between their pallet engaging position, in which
they project through slots 64, 66 into the housing of unit 20,
i.e. inside frame wall 22 (figures 1 and 2), and their pallet
clearing position in which they are located outside the housing
or frame wall 22 of unit 20 (figure 3). It is understood that
the pivoting means behind the other side wall 24 is identical
thereto.
Controls 84 are installed on the exterior of frame
wall 22 on side wall 26 (only), with which it is possible to
selectively control cylinders 51 and 80, 80 through control air
tubes 85a, 85b, respectively (figures 4 and 5). The two smaller
cylinders controlling the pivotal movement of fingers 52, 54,
56, 58 are controlled simultaneously, i.e. activation of both
cylinders together is compulsory, while it is possible to
control the larger cylinder 51 independently.
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Cylinders 51, 80, 80, as already explained, can be
either hydraulic or pneumatic cylinders. The hydraulic
cylinders will provide more power and more reliability to the
unit, and will accordingly increase its speed, while pneumatic
cylinders will reduce the production cost of the unit.
The actuating means are thus used to both raise and
lower the stack of pallets by means of the pallet engaging
fingers. Generally, the vertical movement of the pallet
engaging means of unit 20 along frame 22, more particularly at
its bottom portion along grooves 60, 62, 64, 66, is acquired by
means of the corresponding vertical displacement of actuating
means, since the actuating means support the pallet engaging
means.
Locking means (not shown) are envisioned to prevent
the pivoting means from being activated while the fingers are
loaded with a stack of pallets, for preventing the stack of
pallets from being dropped from a position spaced over ground.
In use, as shown in figures 6 to 8, the unit 20 is
destined to receive a stack of conventional pallets P, of the
type described in the background of the invention section of the
present document. Thus, pallets P are of conventional
rectangular dimensions and have on each small side a pair of
half-moon shaped openings H and on each long side a pair of
large rectangular openings R. The pallets are stacked in the
housing defined by the inner surfaces of frame wall 22, which is
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correctly dimensioned to receive snugly in a non-friction fit
the pallets therein. The pallets P are pushed against rear wall
28 with their opening H facing the respective side walls 24, 26.
In proper position, fingers 52, 54, 56, 58 are vertically
5 aligned with openings H. As shown, the stack of pallets rests
on a lowermost pallet, which in turn rests directly on the
floor, and are located adjacent walls 24, 26, 28.
To add a pallet P' (figure 8) to the stack of pallets
P, the controller of the unit 20 must:
a) activate the small cylinders 80, 80 SO as to retract
their piston rods and consequently pivot the fingers 52, 54, 56,
58 into their pallet clearing position;
b) activate large cylinder 51 SO as to retract its piston
rod and thus downwardly pivot U-shaped lever 36, concurrently
15 downwardly displacing in a vertical, linear movement carriage
members 38, 38 and at the same time fingers 52, 54, 56, 58,
until the fingers are at ground level;
c) activate the small cylinders so as to extract their
piston rods to pivot the fingers into their pallet engaging
20 position: the configuration of figure 6 iS acquired at this
stage, in which the fingers engage openings H in the lowermost
pallet;
d) activate the large cylinder 51 SO as to extract its
piston rod and concurrently upwardly pivot lever 36, thus
vertically upwardly moving carriage members 38, 38 and the
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fingers, until the mark 50 on rod 44 vertically moves beyond the
permanent motionless mark 48, at which time the controller knows
that the pallet stack has been raised of a distance which is
more than the thickness of a pallet: the configuration of
figure 7 is acquired at this stage, in which the whole pallet
stack is supported by the fingers engaging the lowermost pallet,
which itself is held spacedly over ground;
e) insert an additional pallet P' under the stack of
pallets through the frame front opening 30, e.g. with a
conventional pallet pushcart C (as shown in figure 9).
Depending on the initial position of the pivoting
means, i.e. whether the fingers are in their pallet clearing or
pallet engaging position, and on the initial position of the
actuating means, i.e. whether the fingers are raised or lowered,
some of the above-mentioned steps may be unnecessary.
Therefore, the following steps may generally describe the
process for inserting an additional pallet under the stack of
pallets:
a) aligning the pallet fingers, while pivoted outwardly,
~0 with the lowermost pallet;
b) activating the small cylinders 80, 80 for engagement of
the fingers with the lowermost pallet;
c) activating said the large cylinder 51 for raising the
fingers and concurrently the stack of pallets over ground, and
supporting said stack of pallets over ground; and
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d) inserting an additional pallet under the stack of
pallets.
To remove a pallet from the pallet stack, the
controller must:
a) activate the small cylinders 80, 80 to pivot the
fingers in their pallet clearing position;
b) activate the large cylinder 51 to raise the fingers,
until the movable mark 50 comes in register with the motionless
mark 48, in which case the fingers have been raised of a
distance approximately equal to the thickness of one pallet;
c) activate the small cylinders 80, 80 to pivot the
fingers in their pallet engaging position: the fingers will
then engage the second pallet from ground level, i.e. the one
just above the lowermost pallet;
d) activate the large cylinder 51 to raise the fingers
once again, though this time the whole stack from the selected
second pallet and above will be raised; and
e) remove the lowermost pallet, now free from the load of
the pallet stack now spacedly located above it, e.g. by means of
a pushcart.
Again, it may be that some of the above-mentioned
steps are unnecessary to insert a pallet in the stack. The
following steps generally describe the process for removing the
lowermost pallet from under the stack of pallets:
a) aligning the fingers with the second lowermost pallet;
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b) activating the pivoting means, i.e. the small
cylinders, to pivot the fingers into engagement with the second
lowermost pallet;
c) activating the large cylinder 51 so as to raise
carriage members 38, 38 and concurrently the fingers and the
second pallet together with the stack of pallets located above
the second pallet, and support same over ground; and
d) removing the now unloaded lowermost pallet from under
the stack of pallets.
To insert or remove a pallet from the stack in the
methods described hereinabove, it is understood that either a
lift truck, a manual pushcart or any other suitable means can be
used.
The opened front face 30 of frame 22 allows access to
the stack of pallets to remove/insert a pallet therein. Thus,
opening 30 must be at least as wide as a pallet and at least
slightly higher than the thickness of a pallet, at the bottom
portion of the frame front face where the lowermost pallet is
located, to allow the inserting/removal of a pallet. It would
be possible to partly close with a frame front wall (not shown)
the front face 30 of frame 22, to frontwardly support the stack
of pallets, through this front wall would have to downwardly
extend short of the bottom portion of unit 20, to define an
opening having minimum dimensions as described hereinabove. In
the preferred mode to carry out the invention illustrated in the
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drawings, the upper rod 34 linking side walls 24, 26 has a
structural purpose, in that it helps to prevent accidental
spacing of side walls 24, 26.
Concerning marks 48 and 50, their relative position is
very important. Their purpose, as suggested in the description
of the process for inserting/removing a pallet in the stack of
pallets, is to allow a rather precise visual monitoring of the
vertical position of the pallet engaging fingers at all times,
and more particularly to monitor the position of the fingers
relative to the lowermost pallet and to the second lowermost
pallet. Indeed, with marks 48, 50, the operator is able to know
without looking at the pallet engaging fingers themselves where
they are positioned relative to the pallets. When the fingers
are positioned at their lowermost position (e.g. to engage the
lowermost pallet), the main large cylinder 51 is lowered to its
minimum height. The distance between movable mark 50 and
motionless mark 48 is then equal to the thickness of one pallet,
e.g. 5.5". If the fingers are raised until the two marks 48, 50
register with one another, then the fingers are aligned with the
second lowermost pallet. If the fingers are raised to their
uppermost position, i.e. until the movable mark 50 is located
higher than the motionless mark 48, then the space under the
fingers is equal to more than the thickness of a pallet (e.g. 8"
over its lowermost position). It is then possible to insert or
remove a pallet from under the stack of pallets, since there
CA 0221~7~9 1997-09-18
exists a play between it and the proximate, spaced, overlying
pallet, e.g. of approximately 2.5". This play allows:
a) a pallet to be inserted between the ground and the
overlying pallet stack without frictional engagement
therebetween; or
b) a pallet to be removed from under the overlying,
vertically spaced stack of pallets by slightly raising it over
ground, though short of the overlying stack of pallets, and then
pulling it out from under the stack of pallets, again without
any frictional engagement therebetween.
It is understood that marks 48, 50 are very helpful in
monitoring the vertical position of the pallet engaging fingers,
but that unit 20 can function without them, the operator then
having to visually evaluate the position of the pallet engaging
fingers relative to the two lowermost pallets in the pallet
stack.
With the pallet stacking and dispensing unit according
to the present invention, it can be seen that, during the pallet
inserting/dispensing operations, at no time does the controller
manually manipulate one or more pallets, and thus excess
physical strain or body wounds are very unlikely, if not
completely prevented.
Figures 9 to 11 show a second embodiment of the
invention. The pallet stacking and dispensing unit 120 of this
embodiment comprises an automated dispenser apparatus 121 for
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automatically dispensing a pallet out of unit 120.
More particularly, unit 120 comprises a frame 122
having two opposite side walls 124, 126 and a rear wall 128
integrally linking side walls 124, 126. Frame 122 defines an
opened front face 130, and opened upper and lower ends 132, 134.
The actuating means, the pivoting means, the pallet engaging
fingers, are all identical to the ones described in the first
embodiment.
Vertical slots 136, 136 and 138, 138 (with only the
ones located at the bottom part of side wall 124 being seen in
figure 9) which receive the pallet engaging fingers 140, 140 and
142, 142 are very short, just long enough to allow fingers 140,
142 to snugly fit therein and clear the area under frame lower
end 134. Frame 122 is mounted spacedly over ground on a number
of short posts 144, with one post 144a supporting the large rear
cylinder 146. As shown in the drawings, there is preferably
provided five posts 144, one at each corner of the substantially
rectangular frame 122, and one (144a) under cylinder 146 for
supporting same. Wide side openings are formed under side walls
124, 126 by the fact that it is mounted spacedly over ground,
with these openings being wider than the width of a pallet, for
reasons which will become obvious hereinafter.
Dispenser device 121 comprises a rail member 148
transversely installed under frame 122, parallel to rear wall
128 and adjacent thereto, rail member 148 being fixed to the
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three rear posts 144, 144, 144a, and vertically aligned with
rear wall 128. A dispenser arm member 150 is movable along rail
member 148, and is destined to sidewardly flatly engage the
lowermost pallet P' of the stack of pallets P (see figures 10
and 11). Indeed, once all the above-mentioned steps for
removing a pallet have been accomplished except for seizing the
pallet itself, the lowermost pallet rests on the ground, free of
the load of the spacedly overlying stack of pallets which is now
supported by fingers 140, 142. By raising fingers 140, 142 into
their upper position, a path is cleared for the transversal
course of dispenser arm member 150 which will move along rail
member 148, to flatly engage the lowermost pallet and slide the
latter out from under frame 122, as shown in figures 10 and 11.
The dispenser device 121 of this second embodiment can
thus dispense a pallet laterally out from under frame 122, for
example onto an endless conveyor belt.
Figure 12 shows a third embodiment of a pallet
stacking and dispensing unit 220 according to the invention.
Unit 220 is similar to the unit 120 of the second embodiment,
except that it comprises conveyor means 221 instead of the
dispenser arm member 150 and rail member 148 of the dispenser
device 121 of the second embodiment.
Conveyor means 221 are shown in this embodiment to be
a plurality of horizontally diposed, tangentially adjacent
though slightly spaced rollers 222 which will receive the
24
CA 0221~7~9 1997-09-18
lowermost pallet P' when it is dropped thereon by the actuating
means, once the fingers (not shown) disengage the pallet P'.
Thus, the pallet P' can be conveyed with the conveyor means 221
to a remote, suitable location, to be loaded with articles.
The rollers 222 can be electrically powered to roll
continuously to automatically convey the pallets to the said
remote location, or they can remain motionless until a person
manually pushes the pallet P' on them to move pallet P' without
having to lift it above ground.
The main advantages of the pallet stacking and
dispensing unit of the present invention, in all three
embodiments, are thus as follows:
a) the unit is self standing, and retrofit installation in
a warehouse is easily accomplished, without any modifications to
lS the warehouse floor or walls;
b) the unit is rather small, i.e. it does not take up much
space around an existing stack of pallets;
c) the unit prevents any manual handling of the pallets
during either the stacking operation or the dispensing operation
thereof, and thus excessive physical strain or wounds are very
unlikely, if not completely prevented;
d) the unit can be used with only minor modifications
thereto in combination with existing conveyor means - perhaps
only the distance between the supporting posts in the embodiment
of figure 12 may have to be adjusted to fit over existing
CA 0221~7~9 1997-09-18
conveyor means;
e) the unit is very easy to operate, since only two bi-
directional buttons (e.g. labelled "extract/retract") are
present in the first embodiment of the invention, i.e. one for
5large cylinder 51 and one for the simulatneously controlled
small cylinders 80, 80; moreover, the visual marks on the side
wall of the unit help the monitoring of the position of the
fingers and help prevent any height adjustment errors by the
operator during use;
10f) the unit is rather simple, in that it does not comprise
a large number of components, and thus the breakage of the unit
is less likely, and its maintenance is made easier; and
g) the production cost of the present unit is relatively
low, when compared to industrial-type units.
15It is understood that any minor modifications which do
not extend beyond the scope of the present invention are
considered to be included therein.
For example, a conveyor belt could be used instead of
rollers 222.
20Also, the frame could be made differently than with
full side wall panels. Indeed, a few vertical posts
transversely attached to one another would suffice.
It is also envisioned that the pallet engaging fingers
be manually operated, e.g. with a handle lever, which would
25lower the production cost of the unit due to the absence of the
26
CA 0221~7~9 1997-09-18
now useless small cylinders 80, 80.
Large, main cylinder 51 has been shown to be installed
under U-ch~pe~ lever 36, in all three embodiments. However, it
is envisioned that cylinder 51 could be mounted at any suitable
position. For example, a ceiling structure or panel could be
provided on top of frame 22, and cylinder 51 could then be
installed thereon. Of course, different actuating means would
then have to be provided, for example a cross-rod installed on
top of the cylinder piston and link at its two opposite ends to
the side rods which are attached to the carriage members. This
particular configuration would limit the number of pallets which
could be stacked in a particular unit due to the fixed ceiling
panel, but would reduce the floor area which is used by the
unit, since the large, main cylinder would overlie the frame
structure of the unit.
It is further understood that the pallet stacking and
dispensing unit could be designed to allow any one of the
stacked pallets to be engaged by the pallet engaging fingers, by
providing actuating means that are movable along the whole
height of the frame and by providing slots or similar through
ways that allow the fingers to be horizontally moved or pivoted
in their inner pallet engaging position at any vertical position
along the frame.
