U.S. patent application number 10/696722 was filed with the patent office on 2004-07-29 for pallet dispenser.
Invention is credited to Lancaster, Patrick R. III, Martin, Curtis W..
Application Number | 20040146390 10/696722 |
Document ID | / |
Family ID | 32312520 |
Filed Date | 2004-07-29 |
United States Patent
Application |
20040146390 |
Kind Code |
A1 |
Lancaster, Patrick R. III ;
et al. |
July 29, 2004 |
Pallet dispenser
Abstract
A pallet dispenser and a method for stripping a lowermost pallet
from a vertical stack of at least two pallets is disclosed. The
pallet dispenser includes a pallet magazine for containing the
vertical stack of pallets and a platform disposed below the pallet
magazine. The platform is configured to support the vertical stack
of pallets such that the lowermost pallet rests on the platform.
The pallet dispenser also includes a cantilevered pusher bar
configured to push the lowermost pallet from under the vertical
stack of pallets and out of the pallet magazine. In another
embodiment, the pallet dispenser may include motion means for
providing motion to the stack of pallets.
Inventors: |
Lancaster, Patrick R. III;
(Louisville, KY) ; Martin, Curtis W.; (New Albany,
IN) |
Correspondence
Address: |
Finnegan, Henderson, Farabow,
Garrett & Dunner, L.L.P.
1300 I Street, N.W.
Washington
DC
20005-3315
US
|
Family ID: |
32312520 |
Appl. No.: |
10/696722 |
Filed: |
October 30, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60422514 |
Oct 31, 2002 |
|
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|
Current U.S.
Class: |
414/797.4 |
Current CPC
Class: |
B65G 59/067 20130101;
B65G 57/03 20130101; B65G 2201/0267 20130101 |
Class at
Publication: |
414/797.4 |
International
Class: |
B65H 003/00 |
Claims
What is claimed is:
1. A pallet dispenser for stripping a lowermost pallet from a
vertical stack of at least two pallets, comprising: a pallet
magazine for storing a vertical stack of pallets; a platform
disposed below the pallet magazine, the platform being configured
to support the vertical stack of pallets, wherein the lowermost
pallet at least partially rests on the platform; and a cantilevered
pusher bar configured to push the lowermost pallet from under the
vertical stack of pallets and out of the pallet magazine.
2. The pallet dispenser of claim 1, wherein the pallet magazine
includes a front gap sized to allow passage of the lowermost
pallet.
3. The pallet dispenser of claim 2, wherein the pallet magazine
includes a rear gap sized to allow passage of the pusher bar.
4. The pallet dispenser of claim 3, wherein the pusher bar is
movable between a substantially vertical position and a
substantially horizontal position.
5. The pallet dispenser of claim 4, wherein when in the
substantially horizontal position, the cantilevered pusher bar is
movable through the rear gap of the magazine to the front gap.
6. The pallet dispenser of claim 1, wherein the cantilevered pusher
bar is configured to move, while in a resetting position, from a
position adjacent a front of the magazine to a position adjacent a
rear of the magazine.
7. The pallet dispenser of claim 6, wherein when in the resetting
position, the pusher arm is in a substantially vertical
position.
8. The pallet dispenser of claim 1, further including rotating
means for rotating the pusher bar about an axis to move the pusher
bar between a dispensing position and a resetting position.
9. The pallet dispenser of claim 8, wherein the dispensing position
is a substantially horizontal position, and the resetting position
is a substantially vertical position.
10. The pallet dispenser of claim 8, wherein the rotating means is
a motor operably associated with the pusher bar, for rotating the
pusher bar.
11. The pallet dispenser of claim 1, wherein the platform includes
a smooth metal plate.
12. The pallet dispenser of claim 1, wherein the platform includes
non-driven rollers.
13. The pallet dispenser of claim 1, further including means for
adjusting the size of an interior of the pallet magazine.
14. The pallet dispenser of claim 1, further including: a pusher
carrier rotatably attached to the pusher bar; and a pusher guide
configured to guide movement of the pusher carrier.
15. The pallet dispenser of claim 1, further including a palletizer
disposed adjacent the pallet dispenser, the pusher bar being
configured to push the pallet from the pallet magazine to the
palletizer.
16. The pallet dispenser of claim 1, further including motion means
for providing motion to the vertical stack of pallets in the
magazine.
17. The pallet dispenser of claim 16, wherein the motion means
includes at least a portion of the platform.
18. The pallet dispenser of claim 16, further including: a sensor
associated with the pusher bar, the sensor being adapted to
determine a jam condition of the lowermost pallet; and a controller
for activating the motion means when the sensor determines the jam
condition.
19. The pallet dispenser of claim 16, wherein the motion means
includes a motion bar extending through at least a portion of the
platform, and a motor for moving the motion bar.
20. The pallet dispenser of claim 19, wherein the motion means
further includes a motion shaft eccentrically attached to an output
shaft of the motor, the motion shaft also being attached to the
motion bar, such that the motion shaft drives the motion bar to
provide motion to the stack of pallets.
21. The pallet dispenser of claim 19, wherein the motion bar
includes rollers mounted thereon.
22. The pallet dispenser of claim 1, wherein the pallet magazine is
cantilevered.
23. A method of dispensing a lowermost pallet from a vertical stack
of pallets, comprising: placing a stack of pallets in a pallet
magazine; supporting the stack of pallets with a platform of the
magazine; and pushing a lowermost pallet of the stack of pallets
with a cantilevered pusher bar to strip the lowermost pallet from
the stack.
24. The method of claim 21, wherein pushing the lowermost pallet
includes pushing the lowermost pallet through a gap in the
magazine.
25. The method of claim 24, wherein pushing the lowermost pallet
includes pushing the pallet through a front gap in the
magazine.
26. The method of claim 25, wherein pushing the lowermost pallet
further includes moving the pusher arm through a rear gap in the
magazine.
27. The method of claim 23, further including the step of
restraining at least a portion of the stack of pallets in the
magazine with a wall of the magazine.
28. The method of claim 23, further including loosening the
lowermost pallet from the stack of pallets.
29. The method of claim 28, wherein loosening the lowermost pallet
includes activating a motion assembly to provide motion to the
stack of pallets.
30. The method of claim 23, further including providing motion to
the stack of pallets while pushing the lowermost pallet with the
cantilevered pusher arm.
31. The method of claim 30, further including sensing when the
lowermost pallet catches on a portion of at least one of another
pallet and the magazine.
32. The method of claim 31, further including providing motion to
the stack of pallets to loosen the lowermost pallet from the
stack.
33. The method of claim 29, wherein providing motion to the stack
of pallets includes moving at least a portion of the platform.
34. The method of claim 28, wherein providing motion to the stack
of pallets further includes moving to a motion bar, the motion bar
forming at least a portion of the platform.
35. The method of claim 34, wherein providing motion to the stack
of pallets further includes rotating a motion shaft associated with
the motion bar, to raise and lower the motion bar.
36. The method of claim 34, wherein providing motion to the stack
of pallets includes moving the motion bar in a circular motion to
provide the motion, the motion causing the lowermost pallet to move
in a substantially vertical direction.
37. The method of claim 23, further including: rotating the pusher
bar from a substantially horizontal dispensing position to a
resetting position; and moving the pusher bar from the front of the
pallet magazine to a home position at the rear of the pallet
magazine.
38. The method of claim 23, further including pushing the lowermost
pallet onto a palletizer.
39. A pallet dispenser for stripping a lowermost pallet from a
vertical stack of at least two pallets, comprising: a pallet
magazine for storing a vertical stack of pallets; a platform
disposed below the pallet magazine to support the stack of pallets;
pallet dispensing means for moving the lowermost pallet from a
bottom of the vertical stack and out of the pallet magazine; and
motion means for providing motion to the stack of pallets.
40. The pallet dispenser of claim 39, wherein the motion means is
operably associated with at least a portion of the platform.
41. The pallet dispenser of claim 39, wherein the platform includes
at least one smooth metal plate.
42. The pallet dispenser of claim 39, wherein the platform includes
non-driven rollers.
43. The pallet dispenser of claim 39, wherein the motion means
includes a motion bar extending through at least a portion of the
platform.
44. The pallet dispenser of claim 43, wherein the motion means
further includes a motor for driving the motion bar.
45. The pallet dispenser of claim 44, wherein the motion means
further includes a motion shaft eccentrically attached to an output
shaft of the motor, the motion shaft also being attached to the
motion bar, such that the motion shaft drives the motion bar to
provide motion to the stack of pallets.
46. The pallet dispenser of claim 43, wherein the motion bar
includes rollers mounted thereon.
47. The pallet dispenser of claim 39, further comprising: a sensor
associated with the pusher bar, the sensor being adapted to
determine a jam condition of the lowermost pallet; and a controller
for activating the motion means when the sensor determines the jam
condition.
48. The pallet dispenser of claim 39, wherein the pallet dispensing
means includes a pusher bar.
49. The pallet dispenser of claim 48, further including a
palletizer disposed adjacent the pallet dispenser, the pusher bar
being configured to push the lowermost pallet from the pallet
magazine to the palletizer.
50. The pallet dispenser of claim 48, wherein the pusher bar is a
cantilevered bar positioned adjacent to the pallet magazine.
51. The pallet dispenser of claim 50, further including rotating
means for rotating the pusher bar between a dispensing position and
a resetting position.
52. The pallet dispenser of claim 51, wherein the pusher arm, when
in the dispensing position, is in a substantially horizontal
position and the pusher arm, when in the resetting position, is in
a substantially vertical position.
53. The pallet dispenser of claim 48, wherein the pallet magazine
and the pusher bar are both cantilevered.
54. The pallet dispenser of claim 39, wherein the pallet magazine
includes a front gap sized to allow passage of the lowermost
pallet.
55. The pallet dispenser of claim 54, wherein the pallet magazine
includes a rear gap sized to allow passage of at least a portion of
the pallet dispensing means.
56. The pallet dispenser of claim 55, wherein the pallet dispensing
means is configured to move substantially horizontally through the
pallet magazine from the rear gap to the front gap.
57. The pallet dispenser of claim 39, wherein the pallet dispensing
means is cantilevered pusher bar and is configured to move while in
a resetting position from a front of the magazine to a rear of the
magazine.
58. The pallet dispenser of claim 57, wherein the resetting
position is substantially a vertical position.
59. A method of dispensing a lowermost pallet from a vertical stack
of pallets, comprising: placing a stack of pallets in a pallet
magazine; supporting the stack of pallets on a platform; providing
motion to at least a portion of the stack of pallets to reduce
friction between a lowermost pallet of the stack and the remainder
of the stack of pallets; and dispensing the lowermost pallet from
the pallet magazine.
60. The method of claim 59, further including the step of
restraining at least a portion of the stack of pallets in the
magazine with a wall of the magazine.
61. The method of claim 59, further including: sensing when the
lowermost pallet catches on another pallet; and loosening the
lowermost pallet from the stack of pallets.
62. The method of claim 61, wherein loosening includes providing
motion to the stack of pallets.
63. The method of claim 62, wherein providing motion to the stack
of pallets includes moving at least a portion of the platform.
64. The method of claim 61, wherein providing motion to the stack
of pallets further includes moving a motion bar, the motion bar
forming at least a portion of the platform.
65. The method of claim 59, wherein providing motion to the stack
of pallets includes moving at least a portion of the platform.
66. The method of claim 59, wherein providing motion to the stack
of pallets includes moving a motion bar in a circular motion.
67. The method of claim 59, wherein the dispensing step includes
pushing the lowermost pallet with a pusher bar.
68. The method of claim 67, further including, subsequent to the
dispensing step, rotating the pusher bar from a substantially
horizontal dispensing position to a resetting position; and
returning the pusher bar to a home position.
69. The method of claim 59, further including dispensing the
lowermost pallet from the pallet magazine to a palletizer.
70. An apparatus for building and wrapping a load, comprising: a
pallet dispenser including a pallet magazine for storing a vertical
stack of pallets, a platform disposed below the pallet magazine,
the platform being configured to support a stack of pallets,
wherein a lowermost pallet of the stack of pallets at least
partially rests on the platform, and a cantilevered pusher bar
configured to push the lowermost pallet from under the vertical
stack of pallets and out of the pallet magazine; means for building
a load on the dispensed pallet; a packaging material dispenser; and
means for providing relative rotation between the packaging
material dispenser and the load to wrap packaging material around
the load.
71. The apparatus of claim 70, wherein the means for building a
load is a palletizer.
72. The apparatus of claim 70, wherein the means for providing
relative rotation is a turntable.
73. The apparatus of claim 70, wherein the means for providing
relative rotation is a rotating arm.
74. The apparatus of claim 70, wherein the pallet dispenser further
includes motion means for providing motion to the stack of
pallets.
75. The apparatus of claim 74, wherein the pallet dispenser further
includes a motion bar, forming at least a portion of the
platform.
76. A palletizing system, comprising: a pallet dispenser including:
a pallet magazine for storing a vertical stack of pallets; a
platform disposed below the pallet magazine, the platform being
configured to support the stack of pallets, wherein the lowermost
pallet essentially rests on the platform; a cantilevered pusher bar
configured to push the lowermost pallet from under the vertical
stack of pallets and out of the pallet magazine; and a palletizer
disposed adjacent the pallet dispenser, the pusher bar being
configured to push a pallet of the stack of pallets from the pallet
magazine to a palletizer.
77. The palletizing system of claim 76, wherein the pallet magazine
is cantilevered.
78. The palletizing system of claim 76, wherein the platform
includes means for loosening the stack of vertical pallets.
79. The palletizing system of claim 78, wherein the means for
loosening is motion assembly configured to provide vibratory
motion.
80. A method for building and wrapping a load, comprising: placing
a stack of pallets in a pallet magazine; supporting the stack of
pallets on a platform; pushing a lowermost pallet of the stacked
pallets with a cantilevered pusher bar to strip the lowermost
pallet from the stack of pallets; building a load on the dispensed
pallet; providing relative rotation between a packaging material
dispenser and the load to wrap packaging material around the
load.
81. The method of claim 80, further including loosening the stack
of pallets while pushing the lowermost pallet with the cantilevered
pusher arm.
82. The method of claim 80, further including pushing the wrapped
load from a wrapping means with a second cantilevered pusher
arm.
83. An apparatus for dispensing a lowermost pallet from a vertical
stack of pallets, comprising: a pallet dispenser including a pallet
magazine for holding the stack of pallets, and a platform below the
pallet magazine for supporting the stack of pallets; and motion
assembly means associated with the platform of the pallet dispenser
for reducing friction between a lowermost pallet and the stack of
pallets.
84. The apparatus of claim 83, wherein the motion assembly means
includes a motion bar as a portion of the platform.
85. The apparatus of claim 83, further comprising means for pushing
the lowermost pallet from beneath the stack of pallets and out of
the dispenser.
86. The apparatus of claim 85, wherein the means for pushing
includes a cantilevered pusher arm.
87. The apparatus of claim 86, wherein the pusher arm is moveable
between a substantially vertical resetting position and a
substantially horizontal dispensing position.
88. The apparatus of claim 86, wherein the pusher arm includes a
pushing surface and a pallet stack supporting surface.
89. The apparatus of claim 88, wherein the pusher arm further
includes a rolling portion for supporting the stack of pallets.
90. A pallet dispenser for stripping a lowermost pallet from a
vertical stack of at least two pallets, comprising: a pallet
magazine configured to contain the vertical stack of pallets; and a
pusher bar configured to push a lowermost pallet from under the
vertical stack of pallets and out of the pallet magazine, wherein
the pusher bar also is configured to at least partially support the
weight of the pallets on the lowermost pallet to reduce the
friction between the lowermost pallet and the adjacent pallet in
the vertical stack of pallets.
91. The pallet dispenser of claim 90, wherein the pusher bar
includes a roller configured to contact the pallet directly above
the lowermost pallet in the vertical stack of pallets.
92. The pallet dispenser of claim 90, wherein the pusher bar
includes a tapered portion, a bottom of the tapered portion being
configured to have a height lower than a top of the lowermost
pallet, and the top of the tapered portion being configured to have
a height above the top of the lowermost pallet.
93. The pallet dispenser of claim 92, wherein the tapered portion
is configured to lift the vertical stack of pallets off the
lowermost pallet.
94. The pallet dispenser of claim 90, wherein the pusher bar is
configured to transfer at least a part of the weight of the stack
of pallets from off the lowermost pallet to the pusher bar.
95. The pallet dispenser of claim 90, wherein the roller supports
the weight of the pallet stack.
96. The pallet dispenser of claim 90, further comprising a wheel on
the pusher bar.
97. The pallet dispenser of claim 96, wherein the wheel on the
pusher bar is configured to support weight of the pusher bar and
weight of the pallets supported by the pusher arm.
98. The pallet dispenser of claim 97, wherein the wheel is disposed
at one end of the pusher bar.
99. The pallet dispenser of claim 96, further comprising a track
through the pallet magazine configured to support the wheel.
100. The pallet dispenser of claim 90, wherein the pusher bar
includes an angled portion, and a roller adjacent a top of the
angled portion.
101. The pallet dispenser of claim 90, further including a base for
supporting the vertical stack of pallets, the base including
rollers.
102. The pallet dispenser of claim 101, wherein the pallet magazine
is spaced from the base to create a gap, and wherein the magazine
includes walls configured to block the pallets above the lowermost
pallet from exiting the dispenser, the gap being sized to allow the
lowermost pallet to pass through the gap.
103. The pallet dispenser of claim 90; further including rotating
means for rotating the pusher bar about an axis to move the pusher
bar between a dispensing position and a resetting position, the
dispensing position being a substantially horizontal position, and
the resetting position being a substantially vertical position.
104. The pallet dispenser of claim 90, further comprising a
platform including at least one of a smooth metal plate and
non-driven rollers.
105. The pallet dispenser of claim 90, further including means for
adjusting the size of an interior of the pallet magazine.
106. The pallet dispenser of claim 90, wherein the pallet magazine
is a cantilevered pallet magazine.
107. The pallet dispenser of claim 90, further comprising: a sensor
associated with the pusher bar, the sensor being adapted to
determine a jam condition of the lowermost pallet.
108. The pallet dispenser of claim 90, further comprising motion
means for loosening the stack of pallets.
109. The pallet dispenser of claim 108, wherein the motion means
includes a motion bar extending through a platform that supports
the stack of pallets.
110. The pallet dispenser of claim 109, wherein the motion means
includes a motor for driving the motion bar.
111. A method of dispensing a lowermost pallet from a vertical
stack of at least two pallets, comprising: placing a stack of
pallets in a pallet magazine; pushing a lowermost pallet with a
pusher bar to strip the lowermost pallet from the stack of pallets;
and lifting the stacked pallets above the lowermost pallet with the
pusher bar to reduce the friction between the lowermost pallet and
the pallets above it.
112. The method of claim 111, further comprising transferring at
least a part of the weight of the stacked pallets on the lowermost
pallet to the pusher bar to reduce the friction between the
lowermost pallet and the pallet above it.
113. The method of claim 111, wherein lifting the stack of pallets
includes contacting the pallet directly above the lowermost pallet
in the vertical stack of pallets with a roller on the pusher
bar.
114. The method of claim 111, wherein the pusher bar includes a
tapered portion, the bottom of the tapered portion having a height
lower than the top of a lowermost pallet, and the top of the
tapered portion having a height above the top of the lowermost
pallet.
115. The method of claim 111, further comprising supporting at
least a part of the weight of the upper pallets on the pusher
bar.
116. The method of claim 111, wherein the pusher bar includes a
roller and the method further comprises supporting at least a part
of the weight of the pallet stack with the roller.
117. The method of claim 111, wherein the pusher bar is formed as a
wedge having an angled portion extending upward above the level of
the lowermost pallet to contact the pallet directly above the
lowermost pallet.
118. The method of claim 117, wherein the roller is disposed at a
top of the wedge.
119. The method of claim 111, further including a base for
supporting the stack of pallets, the base including one of rollers
and a platform.
120. The method of claim 119, further wherein the walls of the
pallet magazine are spaced from the base to create a gap, the
method further including restraining the pallet above the lowermost
pallet from dispensing from the dispenser.
121. The method of claim 111, further including: rotating the
pusher bar from a substantially horizontal dispensing position to a
substantially vertical resetting position; and returning the pusher
bar past the pallet magazine to a home position.
122. The method of claim 111, further including pushing the
lowermost pallet with the pusher bar to a palletizer.
123. An apparatus for building and wrapping a load, comprising: a
pallet dispenser, including, a pallet magazine for containing a
vertical stack of pallets, a pusher bar configured to push a
lowermost pallet from under the vertical stack of pallets and out
of the pallet magazine, wherein the pusher bar also is configured
to at least partially support the weight of the pallets on the
lowermost pallet to reduce the friction between the lowermost
pallet and the adjacent pallet in the vertical stack of pallets;
means for building a load on the dispensed pallet; and a packaging
material dispenser.
124. The apparatus of claim 123, further comprising means for
providing relative rotation between the packaging material
dispenser and the load to wrap packaging material around the
load.
125. The apparatus of claim 124, wherein the means for providing
relative rotation is a turntable.
126. The apparatus of claim 124, wherein the means for providing
relative rotation is a rotating arm.
127. The apparatus of claim 123, wherein the means for building a
load is a palletizer.
128. The apparatus of claim 123, wherein the pusher bar comprises a
roller configured to contact the pallet directly above the
lowermost pallet in the vertical stack of pallets.
129. The apparatus of claim 123, wherein the pusher bar includes a
tapered portion, a bottom of the tapered portion being configured
to have a height lower than a top of a lowermost pallet, and a top
of the tapered portion being configured to have a height above the
top of the lowermost pallet.
130. The apparatus of claim 129, wherein the tapered portion is
configured to lift the vertical stack of pallets off the lowermost
pallet.
131. The apparatus of claim 123, wherein the pusher bar is
configured to transfer at least a part of the weight of the stack
of pallets from off the lowermost pallet to the pusher bar.
132. The apparatus of claim 123, further comprising a wheel on the
pusher bar, and a track extending through the pallet magazine
configured to support the wheel.
133. A method for building and wrapping a load, comprising: placing
a stack of pallets in a pallet magazine; supporting the stack of
pallets on a platform; pushing a lowermost pallet of the stack of
pallets with a cantilevered pusher bar to strip the lowermost
pallet from the stack of pallets; building a load on the dispensed
pallet; providing relative rotation between a packaging material
dispenser and the load to wrap packaging material around the
load.
134. The method of claim 133, further including the step of
restraining the pallets of the stack of pallets that are above the
lowermost pallet from being dispensed from the magazine.
135. The method of claim 133, further including providing motion to
the stack of pallets while pushing the lowermost pallet with the
cantilevered pusher arm.
136. The method of claim 135, wherein the motion is vibratory
motion.
Description
[0001] This application claims priority under 35 U.S.C. .sctn. 119
based on U.S. Provisional Application No. 60/422,514, filed Oct.
31, 2002, the entire disclosure which is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] This invention relates to a pallet dispenser. More
particularly, this invention relates to a pallet dispenser for
dispensing pallets to a palletizer that builds loads on a
pallet.
BACKGROUND OF THE INVENTION
[0003] Manufacturing and delivery industries often load pallets
with products for ease of handling and delivery. Typically, a
manufacturing facility keeps a large number of pallets on hand to
be used for this handling and delivery. Pallet dispensers are often
used to store the pallets prior to their use. Pallet dispensers
feed empty pallets to palletizers for load building, and in some
cases, to wrapping systems for subsequent wrapping of the pallet
load.
[0004] Pallet dispensers typically operate by vertically separating
the lowermost pallet in a stack from the remainder of the stack of
pallets, and conveying the lowermost pallet from the bottom of the
stack. This vertical separation eliminates any friction between the
lowermost pallet and the remainder of the stack. One type of a
pallet dispenser inserts a securing device, such as forks,
pinwheels, or clamps, into the pallet located directly above the
lowermost pallet. The securing device is then used to raise the
stack of pallets off of the lowermost pallet. Finally, the
lowermost pallet is dispensed out from underneath the stack of
pallets.
[0005] Another type of a pallet dispenser inserts forks or other
securing devices into the pallet directly above the lowermost
pallet. However, instead of raising the stack of pallets off of the
lowermost pallet, as explained above, the stack of pallets is
suspended in place, while the lowermost pallet is lowered away from
the stack of pallets. The lowermost pallet is then conveyed from
the pallet dispenser. Vertically separating the lowermost pallet
from the stack of pallets eliminates the resistance and friction
between the stack and the lowermost pallet.
[0006] In order to dispense pallets of varying thickness, or
pallets of different dimensions, the above-described dispensers
require mechanical adjustment. If the thickness of the pallets
within a given stack varies, the height of the forks, pinwheels or
clamps must be adjusted to align them with the pallet directly
above the lowermost pallet. If the dimensions of the pallets vary,
the dispensers must be adjusted so that the forks or securing
devices still extend into the pallets. Accordingly, when frequent
changeover in pallet size is required, the dispensers have
downtime, decreasing efficiency in the loading of product.
[0007] Another type of pallet dispenser uses an endless conveyor to
push a pallet from the bottom of the stack of pallets. One drawback
to this type of system is that driving mechanisms are required
beneath the stack of pallets, thereby requiring the pallet
dispenser to be elevated above the ground. This reduces
accessibility to the dispenser when the dispenser is loaded by
hand, which may result in fewer pallets being loaded at any one
time.
[0008] Another drawback to prior art pallet dispensers is that they
may be expensive to build, and therefore purchase. Because of this,
smaller manufactures may determine that pallet dispensing systems
are cost-prohibitive, and instead opt to not use dispensers at all.
Further, because of their complex nature, the above described
dispensers may be costly and difficult to maintain.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to pallet dispensers and
methods for dispensing a pallet from a pallet dispenser that
provides advantages and obviates a number of problems in earlier
dispensers and methods.
[0010] According to one aspect, the invention is directed to a
pallet dispenser for stripping a lowermost pallet from a vertical
stack of at least two pallets. It includes a pallet magazine for
storing the vertical stack of pallets, and a platform disposed
below the pallet magazine. The platform may be configured to
support the vertical stack of pallets.
[0011] In another aspect, a cantilevered pusher bar may be
configured to push the lowermost pallet from under the vertical
stack of pallets and out of the pallet magazine. In another aspect,
the pallet magazine may include a front gap sized to allow passage
of the lowermost pallet. It may also include a rear gap sized to
allow passage of the pusher bar. The pusher bar may be movable
between a substantially vertical position and a substantially
horizontal position. When in the substantially horizontal position,
the cantilevered pusher bar may be movable through the rear gap of
the magazine to the front gap. The cantilevered pusher bar may be
configured to move, while in a resetting position, from a position
adjacent a front of the magazine to a position adjacent a rear of
the magazine, and may be in a substantially vertical position.
[0012] In another aspect, rotating means for rotating the pusher
bar about an axis to move the pusher bar between a dispensing
position and a resetting position may be included. The rotating
means may be a motor operably associated with the pusher bar, for
rotating the pusher bar.
[0013] In another aspect, the platform may include a smooth metal
plate or may include non-driven rollers. The dispenser may also
include means for adjusting the size of an interior of the pallet
magazine.
[0014] In one aspect, a pusher carrier may be rotatably attached to
the pusher bar and a pusher guide may be configured to guide
movement of the pusher carrier. A palletizer may be disposed
adjacent the pallet dispenser. The pusher bar may be configured to
push the pallet from the pallet magazine to the palletizer.
[0015] In yet another aspect, motion means may provide motion to
the vertical stack of pallets in the magazine. It may include at
least a portion of the platform. A sensor may be associated with
the pusher bar, and may be adapted to determine a jam condition of
the lowermost pallet. A controller may activate the motion means
when the sensor determines the jam condition. The motion means may
include a motion bar extending through at least a portion of the
platform, and a motor for moving the motion bar. It may further
include a motion shaft eccentrically attached to an output shaft of
the motor. The motion shaft also may be attached to the motion bar,
such that the motion shaft drives the motion bar to provide motion
to the stack of pallets. The motion bar may include rollers mounted
thereon. In another aspect, the pallet magazine is
cantilevered.
[0016] In another aspect, it includes dispensing means for moving
the lowermost pallet from a bottom of the vertical stack and out of
the pallet magazine, and motion means for providing motion to the
stack of pallets. The motion means may be operably associated with
at least a portion of the platform. It may include a motion bar
extending through at least a portion of the platform.
[0017] In another aspect, a pusher bar configured to push a
lowermost pallet from under the vertical stack of pallets and out
of the pallet magazine, wherein the pusher bar also is configured
to at least partially support the weight of the pallets on the
lowermost pallet to reduce the friction between the lowermost
pallet and the adjacent pallet in the vertical stack of
pallets.
[0018] In one aspect, the pusher bar may include a roller
configured to contact the pallet directly above the lowermost
pallet in the vertical stack of pallets. It may also include a
tapered portion. A bottom of the tapered portion may be configured
to have a height lower than a top of the lowermost pallet, and a
top of the tapered portion may be configured to have a height above
the top of the lowermost pallet. The tapered portion may be
configured to lift the vertical stack of pallets off the lowermost
pallet. In another aspect, the pusher bar may be configured to
transfer at least a part of the weight of the stack of pallets from
off the lowermost pallet to the pusher bar.
[0019] In another aspect, the roller supports the weight of the
pallet stack. A wheel may be included on the pusher bar and may
support weight of the pusher bar and weight of the pallets
supported by the pusher arm. The wheel may be disposed at one end
of the pusher bar. A track through the pallet magazine may be
configured to support the wheel.
[0020] In another aspect, the pusher bar includes an angled portion
and a roller adjacent a top of the angled portion. In yet another
aspect, a base may support the vertical stack of pallets. It may
include rollers.
[0021] In another aspect of the invention, a method of dispensing a
lowermost pallet from a vertical stack of pallets is provided. It
includes placing a stack of pallets in a pallet magazine and
supporting the stack of pallets on a platform of the magazine. It
also includes pushing a lowermost pallet of the stack of pallets
with a cantilevered pusher bar to strip the lowermost pallet from
the stack. In one aspect, it includes loosening the lowermost
pallet from the stack of pallets.
[0022] In another aspect, motion is provided to the stack of
pallets to reduce the friction between a lowermost pallet of the
stack and the remainder of the stack of pallets, and the lowermost
pallet is dispensed from the pallet magazine.
[0023] In yet another aspect, the invention is directed to an
apparatus for building and wrapping a load. It may include a pallet
dispenser and means for building a load on the dispensed pallet. It
may also include a packaging material dispenser and means for
providing relative rotation between the packaging material
dispenser and the load to wrap packaging material around the
load.
[0024] In one aspect, the means for building a load is a
palletizer. The means for providing relative rotation may be a
turntable, and the means for providing relative rotation is a
rotating arm.
[0025] In another aspect, the invention is directed to a
palletizing system. It may include a pallet dispenser and a
palletizer disposed adjacent the pallet dispenser. The pusher bar
may be configured to push a pallet of the stack of pallets from the
pallet magazine to the palletizer. The means for loosening may be a
motion assembly configured to provide vibratory motion.
[0026] In yet another aspect, a method for building and wrapping a
load is disclosed. It includes pushing a lowermost pallet of the
stacked pallets with a cantilevered pusher bar to strip the
lowermost pallet from the stack of pallets. It also includes
building a load on the dispensed pallet and providing relative
rotation between a packaging material dispenser and the load to
wrap packaging material around the load. It may also include
loosening the stack of pallets while pushing the lowermost pallet
with the cantilevered pusher arm.
[0027] In yet another aspect, the invention is directed to an
apparatus for dispensing a lowermost pallet from a vertical stack
of pallets. It may include a pallet dispenser including a pallet
magazine for holding the stack of pallets, and a platform below the
pallet magazine and motion assembly means associated with the
platform of the pallet dispenser for reducing friction between a
lowermost pallet and the stack of pallets.
[0028] In yet another aspect, a method of dispensing a lowermost
pallet from a vertical stack of at least two pallets may include
lifting the stacked pallets above the lowermost pallet with the
pusher bar to reduce the friction between the lowermost pallet and
the pallets above it. In another aspect, the method may include
transferring at least a part of the weight of the stacked pallets
on the lowermost pallet to the pusher bar to reduce the friction
between the lowermost pallet and the pallet above it.
[0029] In another aspect, the method may include contacting the
pallet directly above the lowermost pallet in the vertical stack of
pallets with a roller on the pusher bar.
[0030] Additional objects and advantages of the invention will be
set forth in part in the description which follows, and in part
will be obvious from the description, or may be learned by practice
of the invention. The advantages of the invention will be realized
and attained by means of the elements and combinations particularly
pointed out in the appended claims.
[0031] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the invention, as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The foregoing and other features and advantages of the
invention will be apparent from the following more particular
description of the invention, as illustrated in the accompanying
drawings.
[0033] FIG. 1 is a pictorial representation showing an isometric
view of a load building and wrapping system incorporating a pallet
dispenser according to an aspect of the present invention.
[0034] FIG. 2 is a pictorial representation showing an isometric
view of a pallet dispenser according to an aspect of the present
invention.
[0035] FIG. 3 is schematic showing a rear view of a pallet
dispenser showing a pathway of movement of a pusher arm of the
pallet dispenser, according to one aspect of the invention.
[0036] FIG. 4 is an schematic showing a isometric view of a pusher
assembly of a palletizer according to one aspect of the present
invention.
[0037] FIG. 5 is a schematic showing a front view of the pusher
assembly of FIG. 4.
[0038] FIG. 6 is a pictorial representation showing an isometric
view of a motion assembly of a pallet dispenser according to an
aspect of the present invention.
[0039] FIG. 7 is a schematic of a cross-sectional view of the
motion assembly of FIG. 6.
[0040] FIG. 8 is a schematic showing an end view of motion and
output shafts of the motion assembly of FIGS. 6 and 7.
[0041] FIG. 9 is a schematic showing an end view of a motion bar of
the motion assembly of FIG. 6.
[0042] FIG. 10 is a schematic showing an isometric view of a pallet
dispenser according to one aspect of the present invention.
[0043] FIG. 11 is a block diagram of a controller and sensor
assembly used with a pallet dispenser according to one aspect of
the present invention.
[0044] FIG. 12 is a pictorial representation of a pallet dispenser
according to one aspect of the present invention.
[0045] FIG. 13 is a pictorial representation of a pusher arm
according to one aspect of the present invention.
[0046] FIGS. 14-18 are pictorial representations of side views
showing a pallet dispenser during operation according to one aspect
of the present invention.
[0047] FIG. 19 is a schematic of a top view of a pallet dispenser
according to one aspect of the present invention.
[0048] FIG. 20 is a schematic of a side view of the pallet
dispenser of FIG. 19.
DESCRIPTION OF THE EMBODIMENTS
[0049] Reference will now be made in detail to exemplary
embodiments of the invention, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers will be used throughout the drawings to refer to the same
or like parts.
[0050] The present invention is a pallet dispenser having a pallet
magazine and a platform for supporting pallets in the magazine. The
pallet dispenser provides pallets to a pallet loading system
without requiring expensive equipment to vertically separate the
stack of pallets by raising or suspending the stack of pallets off
of the lowermost pallet. Instead, the present invention may use a
cantilever pusher system to push the lowermost pallet from the
stack of pallets in the dispenser. Further, the present invention
does not need to rely upon pallets having uniform dimensions
because the pallet dispenser does not include elements that are
dependent upon the size of the pallets, such as forks or other
restraining systems that grip or extend into the pallets.
[0051] Finally, the present invention may include a cantilever or
side-mounted pushing system. Accordingly, the pallet dispenser of
the present invention may lie low on the ground, making it more
accessible than previous pallet dispensers, that have mechanisms
located below the stack of pallets. Accordingly, an operator may
more easily load the pallets, and ultimately, may be able to load a
higher number of pallets into the dispenser, improving
efficiency.
[0052] The present invention may also include a motion assembly for
providing motion to pallets in the magazine to reduce the
frictional forces between the lowermost pallet and the pallet
immediately above it. For example, during dispensing, the lowermost
pallet rubs against the pallet directly on top of it, as it is
pushed from the pallet magazine. Because pallets are frequently
reused, the pallets may have damaged boards or other anomalies,
including nails or warped deck boards that cause the lowermost
pallet to catch on the pallet directly above it, or vice versa.
Some embodiments of the present invention may enable the pallets to
"hop" over irregularities on adjacent pallets.
[0053] According to one aspect of the present invention, a pallet
dispenser is provided to supply pallets to a load building and
wrapping system. As shown in FIG. 1, a load building and wrapping
system 100 may include a pallet conveyer 115 for transporting
pallets between the pallet dispenser and a load building device,
such as a palletizer 120. The palletizer 120 may be used to load
product or packages onto an empty pallet and could be any
palletizer known in the art.
[0054] The load building and wrapping system 100 may also include a
packaging material dispenser 130. The packaging material dispenser
may be associated with the palletizer 120 forming a single unit, or
may be separate from the palletizer 120. As embodied herein, and
shown in FIG. 1, the packaging material dispenser 130 includes a
mast, on which a dispensing component may move. The packaging
material dispenser 130 dispenses a sheet of packaging material in a
web form, such as stretch-wrap packaging material. Various other
packaging materials, generally not considered to be stretch wrap
materials, such as netting, strapping, banding, and tape, can be
used as well. The packaging material dispenser 130 may be any
standard packaging material dispenser known in the art.
[0055] The load building and wrapping system 100 may also include
means for providing relative rotation between the dispenser and the
load to wrap packaging material around the sides of the load. As
embodied herein, and shown in FIG. 1, the means for providing
relative rotation may include a rotatable turntable 135.
Alternatively a wrapping arm or ring to rotate the dispenser around
the load may be provided.
[0056] The pallet conveyer 115 may include either driven or
non-driven rollers for advancing the pallet from the palletizer 120
to a load wrapping area, which may include the packaging material
dispenser 130 and turntable 135. Alternatively, the pallet conveyer
115 may use drag chains, belts, transfer ball bearings, or other
powered or non-powered low friction elements, including a smooth
surface.
[0057] As shown in FIGS. 1 and 2, a pallet dispenser 200 for
holding empty pallets is provided. The pallet dispenser 200 may
include a rectangular pallet magazine 201, a platform 214 below the
pallet magazine, and a pusher assembly 230 for pushing a pallet
from the magazine 201. The pallet dispenser 200 may include a front
dispensing end 202 facing the palletizer 120, and a rear end 203
opposite the dispensing end 202. The pallet dispenser 200 shown in
FIG. 1 includes a stack of pallets 152 in the dispenser 200. A
lowermost pallet 150 of the stack of pallets 152 is in a position
to be dispensed from the pallet dispenser 200.
[0058] Although the invention is described as a pallet dispenser
for dispensing a lowermost pallet from the pallet stack, the pallet
dispenser also could be configured to dispense any lower pallet
from the stack. A lower pallet is any pallet having another pallet
above it. In this application, wherever the term "lowermost" is
used, it is intended to include the bottom pallet of a stack, in
addition to a lower pallet that may not be the lowermost pallet,
but that has another pallet above it. For example, in one
embodiment, the pallet dispenser may be configured to dispense a
second lowermost pallet from the pallet stack.
[0059] The pallet dispenser 200 may include a footing bar 206 that
provides a stable framework for supporting the magazine 201 and the
platform 214. Vertical support bars 205 may extend from the footing
bar 206 to the magazine 201 to provide rigid support to the pallet
magazine 201. In one embodiment, the vertical support bars 205 and
the footing bar 206 are steel bars. However, the vertical support
bars 205 and the footing bar 206 could be formed of other materials
rigid enough to support and hold the pallet magazine 201 above the
platform 214. The vertical support bars 205 may be welded, bolted,
or otherwise attached to the footing bar 206.
[0060] As embodied herein, and shown in FIGS. 1 and 2, the pallet
magazine 201 may include four walls or sides 204, including
adjustable horizontal support bars 207 that may extend around three
of the sides 204. In the exemplary embodiment shown, the pallet
magazine 201 is a cantilevered magazine, meaning that at least one
side of the magazine is not supported from below. Instead, in this
embodiment, the cantilevered side is suspended by the adjustable
horizontal support bars 207, which provide support to, and suspend
the cantilevered pallet magazine 201. The adjustable horizontal
support bars 207 may be supported on a non-cantilever side by the
vertical support bars 205. The adjustable horizontal support bars
207 may be formed of steel, or other material rigid enough support
the cantilevered magazine without significant deformation.
[0061] In the exemplary embodiment shown in FIGS. 1 and 2, the
adjustable horizontal support bars 207 are located on three sides
of the pallet magazine 201. A loading side does not have the
adjustable horizontal support bars 207 and may be used to fill the
pallet magazine 201 with pallets 152. Because an adjustable
horizontal support bar 207 does not extend across the loading side,
a fork lift may be used to place a stack of pallets in the
magazine. However, it should be noted that the horizontal support
bars 207 could be on two sides, or all four sides of the pallet
magazine 201.
[0062] The adjustable horizontal support bars 207 may be nested
rails having a number of holes 214 formed within the rails. The
nested rails may be configured to slide relative to each other and
bolts may be inserted in the holes to secure the adjustable
horizontal support bars at a desired length. Accordingly, although
not required, the size of the interior of the pallet magazine 201
may be adjusted to make the magazine larger or smaller. Other
methods of adjusting the size of the interior of the pallet
magazine may be used, as would be apparent to one skilled in the
art.
[0063] The pallet magazine 201 may include corner panels at each
corner of the magazine 201. The corner panels, along with the
adjustable horizontal support bars 207, define the walls 204 and
the interior of the pallet magazine 201. The corner panels may
include cantilever corner panels 208 and non-cantilever corner
panels 210. The cantilever corner panels 208 may be located on a
side of the magazine 201 adjacent the pusher assembly 230 and are
suspended in the air by the adjustable horizontal support bars 207.
As such, the cantilever corner panels 208 are not supported from
below by the vertical support bars 205. The cantilever corner
panels 208 are suspended at a height that allows the pusher
assembly 230, located at the side of the magazine 201, to push a
pallet out from below the pallet magazine 201. The cantilever
corner panels 208 may be welded, screwed, bolted or otherwise fixed
to the adjustable horizontal support bars 207.
[0064] The non-cantilever corner panels 210 may be located on the
corners of the pallet dispenser 200 having the vertical support
bars 205. They may extend from the footing bar 206 vertically
upward, and provide additional support to the horizontal support
bars 207. Accordingly, these need not be suspended in the air, but
may be supported by either the footing bar 206, or the vertical
support bars 205. The corner panels 210 provide rigidity to the
interior of the pallet magazine 201, and may be formed of steel, or
other material, as would be apparent to one skilled in the art.
[0065] In the embodiment shown, the corner panels 208 and 210 cover
only the corners of the pallet magazine 201, rather than the sides
204, so that spaces are provided between each corner panel. The
spaces allow the corner panels 208 and 210 to be moved close
together by adjusting length of the adjustable horizontal support
bars 207, to define a small pallet magazine, without overlapping of
the corner panels. Likewise, the corner panels may be moved further
apart by extending the adjustable horizontal support bars 207.
Additionally, the spaces enable an operator to easily view the
stack of pallets in the magazine to determine whether the pallet
magazine should be refilled with empty pallets.
[0066] Due to its cantilevered structure, the pallet magazine 201
includes a front gap 240 and a rear gap 242 formed below the
cantilever corner panels 208. The rear gap 242 is sized to allow a
pushing element of the pusher assembly 230 to enter into and travel
through the pallet magazine 201. The front gap 240 is sized to
allow the lowermost pallet 150 from the stack of pallets 152 and
the pushing element to pass out of the magazine 201. The corner
panels 208 and 210 along the front gap 240 are positioned to
restrain all the pallets in the stack except the lowermost pallet.
Accordingly, the lowermost pallet is stripped out from underneath
the stack of pallets. The front and rear gaps could be gaps within
the range of about 4-7 inches, but could also be gaps having other
dimensions.
[0067] In the exemplary embodiment shown in FIGS. 1 and 2, the
corner panels 208 and 210 include flanged tops 212. The flanged
tops 212 extend from the top edges of the corner panels 208 and
210, and allow a user or operator to easily place empty pallets
into the pallet magazine 201 through the top. The flanged tops 212
align and guide the empty pallets into the pallet magazine 201.
[0068] The pallet dispenser 200 may include a platform 214 for
supporting a stack of pallets, such as stack of pallets 152. The
platform 214 may be positioned below the magazine 201 and may
includes floor panels 216. As shown in FIG. 2, the platform 214 may
include two floor panels 216. Alternatively, the platform 214 may
have one panel, or more than two panels. The floor panels 216 are
preferably smooth metal plates, allowing a pallet to slide on the
panels with a low amount of friction. Alternatively, the floor
panel 216 may include (or comprise) non-driven rollers or driven
rollers (or other elements of suitable material) as would be
apparent to one skilled in the art.
[0069] As shown in FIG. 2, a motion bar 218 extends between the
floor panels 216, and may form a part of the platform 214. The
motion bar 218 may operate with the floor panels 216 to support a
stack of pallets within the pallet magazine 201. Although only one
motion bar 218 is shown in the platform 214, additional motion bars
may be used. Furthermore, the size of the motion bar may be
increased or decreased, or the whole platform 214 may be the motion
bar 218.
[0070] Threaded bars 220 are associated with the platform 214 to
provide height and balance to the platform 214. Each floor panel
216 of the platform 214 may be associated with at least one of the
threaded bars 220, which may be rotated to adjust the height of the
platform 214 relative to the footing bar 206. The threaded bars 220
may be turned to raise or lower the platform 214 and to level or to
slant the platform 214 as desired.
[0071] The pusher assembly 230 may operate to provide the necessary
force to dispense a pallet from the pallet dispenser 200. It may
include a pusher arm 232, a pusher leg 234, and a pusher carrier
236. The pusher assembly 230 may be driven along a pusher guide
238, to push the pallet from the dispenser 200.
[0072] FIG. 3 is a rear view of the pallet dispenser 200. As shown,
the pusher arm 232 may be raised from a substantially horizontal
position or a dispensing position 260 to a substantially vertical
position or a resetting position 262. When in the resetting
position, the pusher arm 232 is returned from the front dispensing
end 202 of the pallet dispenser 200 to the rear end 203 after
dispensing a pallet, such as the lowermost pallet 150 of FIG. 1. It
should be noted that the resetting position 262 need not be
vertical, but need only be a position that allows the pusher arm to
move past the pallet magazine 201. Likewise, the dispensing
position 260 need not be horizontal, but could be any position that
allows the pusher arm 232 to contact and move the lowermost pallet
150 from the pallet magazine 201.
[0073] In operation, the pusher arm 232 pushes a lowermost pallet
150 from the pallet magazine 201. The pusher arm 232 is set at a
height such that it pushes only the lowermost pallet 150 from the
stack 152. In the dispensing position 260, it travels beneath the
cantilever corner panels 208 through the front and rear gaps 240
and 242 to dispense the lowermost pallet 150 from the stack of
pallets 152. The remainder of the stack of pallets may be
maintained within the pallet magazine 201 by the walls of the
cantilever corner panels 208 and/or the non-cantilever corner
panels 210.
[0074] After pushing the lowermost pallet 150 from the stack 152,
the pusher arm 232 may be rotated about a pivot from the dispensing
position 260 to the resetting position 262. In the resetting
position 262, the pusher arm 232 may be moved from the front of the
pallet magazine 202 to the rear of the pallet magazine 201. Once
the pusher arm 232 arrives at the rear of the pallet magazine 201,
it may be lowered from the resetting position 262 to the dispensing
position 260. At that time, it may be in the "home position," i.e.,
a position to dispense another pallet from the pallet magazine
201.
[0075] FIGS. 4 and 5 show an isometric view and a side view of the
pusher assembly 230 for moving the pallet between the pallet
magazine 201 and a load building surface of the palletizer 120. As
stated above, the pusher assembly 230 includes the pusher arm 232,
and a pusher carrier 236 that rides on a pusher guide 238. In the
exemplary embodiment shown, the pusher arm 232 is a rotating bar
mounted to a linear bearing, and may be driven along the pusher
guide 238. The pusher assembly 230 may be the pusher assembly
disclosed in U.S. application Ser. No. 09/985,156, filed Nov. 1,
2001, and titled "Method and Apparatus for Wrapping a Load," the
entire disclosure of which is incorporated in its entirety herein
by reference.
[0076] A motor 246 with an integrated gear box may be attached to
the pusher carrier 236 to drive the pusher arm 232 along the pusher
guide 238. In such an embodiment, the motor 246 drives rotation of
the pusher arm 232 about an axis determined by the pusher carrier
236. Thus, the pusher arm 232 may be moveable between the resetting
position 262 and the dispensing position 260.
[0077] As shown in FIGS. 4 and 5, the pusher arm 232 and the pusher
leg 234 form an "L" shape. The pusher leg 234 may be disposed upon
the pusher carrier 236. The pusher guide 238 may form a track for
the pusher carrier 236 which carries and moves the pusher arm 232.
The pusher arm 232 may be made of any material of sufficient
strength and rigidity to move pallets from the magazine, and could
be, for example, steel.
[0078] The pallet dispenser of the present invention does not use
expensive equipment to raise or lift the stack of pallets from the
lowermost pallet. Instead, the present invention uses a cantilever
pusher system 230 to push the lowermost pallet from the stack of
pallets. During dispensing, the lowermost pallet rubs against the
pallet directly on top of it, as it is pushed from the pallet
magazine 201. Because pallets are frequently reused, some may have
slight damage. This may cause the lowermost pallet to catch on the
pallet directly above it, or vice versa. In order to reduce the
chance of the pallets catching on each other, or alternatively, to
release the pallets from each other, a motion assembly may be
provided with the pallet dispenser 200 to reduce the friction
forces upon the lowermost pallet and enable the pallets to hop over
irregularities on adjacent pallets.
[0079] FIGS. 6-9 show one embodiment of a motion assembly 270. It
may be associated with the motion bar 218 of the platform 214, and
may be disposed below or adjacent to the platform 214. It may be
used to provide motion to a stack of pallets 152 in the pallet
magazine 201. This motion may be used to counteract the downward
force on the lowermost pallet from the vertical stack of pallets
152 by providing motion, such as, for example, vibration, to the
stack 152 to float the stack 152 above the lowermost pallet 150.
Accordingly, the friction between the lowermost pallet 150 and the
pallet above it is reduced. Furthermore, the friction between the
bottom or sides of the lowermost pallet 150 and the pallet
dispenser 200 is also reduced. The motion may be any motion that
will reduce the force from the stack on the lowermost pallet
including, for example, a vibratory motion or a slower, oscillating
motion.
[0080] The motion assembly 270 may be associated with the motion
bar 218, which preferably forms a part of the platform 214. As
shown in FIGS. 6-9, it may include a motion motor 272, a motion
shaft 276, and pillow bearings 280 located at one end of the motion
bar 218. It may include a motion linkage 288 at the other end of
the motion bar 218.
[0081] FIG. 6 shows the motor 272. It could be any standard motor
known in the art. In one embodiment, the motor 272 is a variable
speed DC motor manufactured by Baldor. It may include an output
shaft 274 that may be eccentrically associated with the motion
shaft 276. As the motor 272 turns the output shaft 274, the motion
shaft 276 eccentrically rotates, providing cyclic motion to the
motion bar 218. In the embodiments shown, the output shaft extends
through a platform support 278 on the underside of the platform
214. It provides stability to the motor 272 as it operates.
[0082] In another embodiment, the motion assembly 270 could include
a cam to raise or lower the motion bar 128, or alternatively, to
directly contact the lowermost pallet 150. In another embodiment, a
hydraulic or pneumatic cylinder is included for providing motion to
the motion bar 218. Other systems for providing motion to the
motion bar or to the pallet stack would be apparent to one skilled
in the art.
[0083] FIG. 7 is another view of the motion assembly 270. As shown
in FIG. 7, the output shaft 274 extends through the motion shaft
276. Pillow bearings 280 may connect the motion shaft 276 to a
support bar 282. It, in turn, may be connected to the motion bar
218. As the output shaft rotates, the motion shaft 276 rotates in
the pillow bearings 280 causing the motion bar 218 to move up and
down in a circular manner or eccentrically. However, for purposes
of the invention, the motion bar need not move in a circular
manner, but may move in other patterns, such as, for example, only
vertically, as would be apparent to one skilled in the art.
[0084] The motion bar 218 is placed to rise above the floor panels
216 of the platform 214 to provide motion to the lowermost pallet
on the platform 214. Accordingly, as the motion assembly 270
rotates the motion shaft 276, the motion bar 218 moves under and
against the stack of pallets in the pallet magazine 201. The
platform supports 618, and or additional supports and bearings 284
may be provided to support and to reduce flexing of the output
shaft 274. In one embodiment, the motion bar 218 is configured such
that roughly two-thirds of the movement of the motion bar occurs
below the platform 214 while one-third of the movement of the
motion bar 218 occurs above the platform 214.
[0085] FIG. 8 shows an end view of the motion shaft 276 and the
output shaft 274. The motion shaft 276 and the output shaft 274 are
keyed together by a key 286. The axis of the motion shaft 276 may
be offset from the axis of the output shaft 274 by about 3/8 of an
inch. However, as would be apparent to one skilled in the art,
other offset amounts could be used. By varying the amount of
offset, the motor speed, and/or the position of the motor 272, the
amount of motion to be transferred to the pallet stack can be
adjusted.
[0086] In another exemplary aspect, the motion bar 218 could be
associated with a hydraulic or pneumatic cylinder to provide the
motion to the motion bar 218. In this embodiment, the hydraulic or
pneumatic cylinder provides a vertical force against the motion bar
218 to pivot the motion bar 218 about a point, to raise and lower
the motion bar 218, or to otherwise provide motion to the motion
bar 218. Other systems of providing motion to the motion bar 218
may be used as would be apparent to one skilled in the art.
[0087] In the embodiment shown in FIGS. 6-9, the motion assembly
270 is connected to the motion bar 218 toward a dispensing end 202
of the motion bar 218. The dispensing end 202 is the end associated
with the dispensing end 202 of the pallet magazine 201. FIG. 9
shows an end view of the motion bar 218 at the rear end 203 of the
pallet magazine 201. Because the motion bar 218 may rotate in a
circular motion, the rear end of the motion bar 218 includes the
motion linkage 288 to accommodate this motion. The motion linkage
288 may include a bearing system having a bar bearing 290 and a
support bearing 294, connected to each other by spanning bars 292.
The support bearing 294 is attached to a fixed portion of the
pallet dispenser 200.
[0088] In one embodiment, the motion assembly 270 is associated
with the motion bar 218 such that each end of the motion bar
simultaneously moves or vibrates, or alternatively, vibrates in an
offset sinusoidal manner. In this embodiment, the output shaft of
the motor could be located centrally under the motion bar, and
bearing systems could be used on both ends. Other systems for
displacing or vibrating the whole motion bar 218 could be used, as
would be apparent to one skilled in the art.
[0089] Further, in one embodiment, the motion bar 218 is a single
floor panel comprising the whole platform 214, as shown in FIG. 10.
Accordingly, in this embodiment, the whole platform provides motion
to move or vibrate the stack of pallets 152. In another embodiment,
the platform includes two or more motion bars that may together
move or vibrate the pallet stack.
[0090] FIG. 11 is a block diagram showing a control system 296 for
the motion assembly 270 that may be used in the pallet dispenser
200. It includes a sensor 298 and a controller 300. It may be
associated with the motion motor 272 of the motion assembly 270.
The control system 296 may be used to activate, alter, or
deactivate the motion assembly 270 when the system determines that
the lowermost pallet is jammed or caught on the pallet above it.
The sensor may be associated with the pusher assembly 230, and may
be configured to detect when the load on the pusher arm 232 exceeds
a preset limit. The preset limit may be set to indicate that the
lowermost pallet has caught on the stack of pallets during
dispensing.
[0091] In one embodiment, the sensor 298 sends a signal to the
controller 300 which monitors the sensor 298. When the sensor
signal exceeds the preset limit, the controller 300 activates the
motion motor 272 to move the motion bar 218, thereby moving the
stack of pallets. Accordingly, in this embodiment, the motion
assembly 270 does not continuously operate but operates only when
the lowermost pallet is caught on the stack of pallets, as
determined by the sensor 298. In another embodiment, when the
signal exceeds the preset limit, the controller 300 sends a signal
to the motion motor 272 to either increase or decrease the motor
speed, in order to change the movement of the motion bar 218. In
still another embodiment, the motion assembly 270 is deactivated
when a sensor signal exceeds the preset limit, thereby shutting
down the dispenser.
[0092] The sensor 298 could be, for example, a current sensor
associated with the pusher carrier 236 to determine when the
current to the pusher carrier 236 exceeds a preset rating,
indicating the magnitude of the load against the pusher arm 232.
The controller 300 could be any standard controller known in the
art. Further, it may be associated with the motor 272 of the motion
assembly 270 to activate or deactivate the motor 272 as is known in
the art.
[0093] In another embodiment, the sensor 298 is a timer for
measuring the length of time taken to dispense a pallet from the
dispenser 200. In this embodiment, if the pallet is not dispensed,
as determined by the position of the pusher arm 232, within a
certain time, the controller 300 determines that the pallet must be
jammed, and will either shut down or provide a different motion to
the pallet.
[0094] In another embodiment, the motion assembly 270 may be
activated when the pusher arm 232 reaches a set position while
passing through the magazine. Likewise, the motion system 270 may
be deactivated when the pusher arm 232 reaches a different position
either in the magazine or after the pusher arm 232 has passed out
of the magazine 201. Alternatively, the motion system 270 may
include a timer that is activated at a preset position in the
dispensing process for a given time in the process.
[0095] FIGS. 12 and 13 show an another embodiment of the pallet
dispenser 200. In this embodiment, the pallet dispenser 200
includes a roller platform 310 and a pusher arm 332 having a pusher
arm body 312, an optional pusher roller 314, and a wheel 316.
[0096] The roller platform 310 may include either driven or
non-driven rollers 311. In one embodiment, the complete platform is
formed of rollers 311. In another embodiment, the roller platform
310 is formed of relatively narrow strips of rollers that may be
included on each side of the pallet magazine 201 to support the
sides of a lowermost pallet in the magazine 201. In the embodiment
shown, the roller platform 310 includes roller conveyers at each
side of the magazine 201. Other configurations could be included as
would be apparent to one skilled in the art.
[0097] In FIGS. 12 and 13, the pusher arm 332 is in the dispensing
position 260, at the rear end 203 of the pallet magazine 201. The
pusher arm 332 operates in substantially the same manner as
described above, pushing a lowermost pallet from the magazine
through a gap between the roller platform 310 and the magazine
walls 204. In this embodiment, the pusher arm body 312 of the
pusher arm 332 includes a taper surface 318, a pushing surface 320,
and a flat surface 322. The pushing surface 320 is configured to
face into the magazine 201, and is configured to directly contact a
pallet in the magazine 201. In this embodiment, the pushing surface
320 is a flat, substantially vertical surface. Other surface
configurations could be used as would be apparent to one skilled in
the art. The flat surface 322 may extend substantially horizontal
to the pallet magazine 201, and together with the pushing surface
320, may form an edge 324. In one embodiment, the edge 324, as well
as the flat surface 322 may be configured to have a height that is
substantially equal to or lower than the top of the lowermost
pallet. Accordingly, any pallet on the lowermost pallet would
extend above the flat surface 322 when the pusher arm 332 is
pushing the lowermost pallet from a stack of pallets.
[0098] The taper surface 318 may be formed adjacent to the flat
surface 320, and may extend at an angle from the flat surface 320.
In one embodiment, the taper surface 318 is angled between 15 and
40 degrees. In one embodiment, the taper surface 318 may be
configured to extend to a height that is higher than the top edge
of the lowermost pallet. It may operate as one side of wedge to
push a pallet on the lowermost pallet up as the pusher arm 332
moves through the pallet magazine 201.
[0099] In the embodiment shown in FIGS. 12 and 13, the pusher
roller 314 may be attached at the top of the taper surface 318. It
may be attached to each end of the pusher bar 332, and may be
configured to turn as the pusher bar 332 moves below the pallet
stack when pushing a lowermost pallet. The height of the pusher
roller 314 may be configured to be higher than the top of the
lowermost pallet, thereby coming into contact with the pallet above
the lowermost pallet, and possibly raising the platform above the
lowermost pallet, as the pusher arm 332 moves through the pallet
magazine 201.
[0100] The wheel 316 may be attached to the end of the pusher arm
332. Accordingly, in the embodiment shown, the weight of the pusher
arm 332 may be supported at both ends. The wheel 316 may be raised
and lowered into the dispensing position and the resetting position
with the pusher arm 332. The wheel 316 may be formed of any
material, but in this embodiment, along with the pusher arm 332, it
is preferably a relatively light material, enabling the pusher arm
332 to be easily moved from the dispensing position 260 to the
resetting position 262.
[0101] The pallet dispenser 200 may also include a track 326
extending through the pallet magazine 201. The track 326 may be any
surface sufficient to support the weight of the pusher arm 332 and
any weight supported by the pusher arm 332. In the embodiments
where the roller platform 310 includes a floor panel, the panel may
provide the support for the wheel 316, obviating any need for the
separate track 326.
[0102] The pusher arm 332 may reduce the friction between the
lowermost pallet and the pallet above it by separating the upper
pallet from the lowermost pallet. In one example, when the pusher
bar 332 pushes a lowermost pallet from the magazine 201, the taper
surface 318 contacts the pallet directly above the lowermost
pallet. As the pusher bar 332 continues to advance through the
magazine 201, the taper surface 318 may force the pallet stack
upward so that the pusher arm 332 may partially support the weight
of the pallet stack. As the pusher arm 332 moves further into the
pallet magazine 201, the weight of the pallet stack continues to
transfer from the lowermost pallet to the pusher arm 332. The wheel
316 on the track 326 becomes a support for the pusher arm 332. As
the weight of the pallet stack becomes supported by the pusher arm
332, the weight is taken off the lowermost stack, providing less
friction, and reducing the chance of interference with nails or
other anomalies on the pallets. Further, the lowermost pallet may
roll on the roller platform 310, further reducing friction between
the lowermost pallet and the platform.
[0103] If the pusher roller 314 is higher than the top of the taper
surface 318, the top of the taper surface 318 may not need to be
higher than the edge of the lowermost pallet because the pusher
roller 314, rather than the taper surface 318, may provide the lift
and contact with the pallet stack. Alternatively, the pusher arm
332 may include a pusher surface and a tapered surface.
Accordingly, there is no flat surface. In another alternative, the
pusher arm 332 may not include a taper surface, and be formed only
of a pusher roller 314 that is configured to support the weight of
the pallet stack when the lowermost pallet is being pushed.
[0104] As shown in FIGS. 12 and 13, the pusher arm 332 may be
driven by the pusher carrier 236 at one side. The wheel 316 may be
a non-driven wheel, and may serve to support the weight of the
pallet stack. Although the pusher bar 332 is supported and driven
at one side by the pusher carrier 236, in this embodiment, the
pusher arm 332 is not a cantilever arm, and therefore need not be
used on a cantilever type system. In one embodiment, the pusher arm
332 with the taper surface may be used in conjunction with the
motion assembly 270 described above.
[0105] According to one aspect of the invention a method for
dispensing a pallet from a pallet dispenser is provided. As shown
in FIG. 14, a lowermost pallet 150 of a pallet stack 152 is
provided in the pallet magazine 201. In FIGS. 14-18, the pallet
stack 152 is a single pallet stacked upon the lowermost pallet 150.
However, the pallet stack 152 could include any number of
additional pallets. As shown in FIG. 14, the pusher arm 232 is
disposed at the rear of the pallet magazine 201 in the dispensing
position 260.
[0106] In operation, the pusher arm 232 enters the pallet magazine
201 through the rear gap 242 and contacts the lowermost pallet 150.
As explained above with reference to FIGS. 4 and 5, the pusher arm
232 may be moved by the pusher carrier 236 along the pusher guide
238. The lowermost pallet 150 is pushed by the pusher arm 232
through the front gap 240 of the pallet magazine 201, as shown in
FIG. 15. The corner panels 208 and 210 restrain the stack of
pallets 152 from moving with the lowermost pallet 150, holding the
stack within the pallet magazine.
[0107] FIG. 16 shows the lowermost pallet 150 traveling out of the
front gap 240 of the pallet magazine 201. FIG. 17 shows the
lowermost pallet 150 completely dispensed from the pallet magazine
201. In this embodiment, the lowermost pallet 150 is pushed onto
the pallet conveyer 115 for loading by a palletizer. The stack of
pallets 152 drops down, and the next pallet on the stack is now in
the lowermost position in the pallet magazine 201.
[0108] As shown in FIG. 18, the pusher arm 232 is then raised from
the dispensing position 260 to the resetting position 262. Once the
pusher arm 232 is raised to the resetting position, the pusher
carrier 236 is moved along the pusher guide 238 from the dispensing
end 202 of the pallet magazine 201 to the rear end 203 of the
pallet magazine 201. At that location, the pusher arm 232 is
rotated from the resetting position 262 to the dispensing position
260, and is ready for additional dispensing.
[0109] The pallet 150 may now be in a loading position for loading
by a palletizer, such as the palletizer 120 described with
reference to FIG. 1. The palletizer could load the pallet 150 using
standard methods known in the art. The loaded pallet could then by
wrapped with packaging material using a packaging material
dispenser, such as the packaging material dispenser 130 described
with reference to FIG. 1.
[0110] FIG. 19 is a top view of another exemplary embodiment of the
pallet dispenser 200. The pallet dispenser 200 is adjacent to a
turntable 135. A packaging material dispenser (not shown) or
palletizer (not shown) may also be provided. In this embodiment,
the pallet dispenser 200 includes a pusher assembly 230 having a
dispenser pusher arm 232 and a turntable pusher arm 350. The pusher
assembly 230 pushes a lowermost pallet 150 from the pallet
dispenser 200 to the turntable 135. Simultaneously, the turntable
pusher arm 350 pushes a loaded palletized load 362 from the
turntable 135 to a load storage or pickup station 364. In this
embodiment, the dispenser pusher arm 232 and the turntable pusher
arm 350 operate in tandem along a common pusher carrier 236 on a
common pusher guide 238. Accordingly, when the pusher arms 232 and
350 are raised from a dispensing position 260 to a resetting
position 262, they move in concert.
[0111] In one embodiment, the distance from the turntable 135 to
the load pickup station 364 is further than the distance from the
pallet dispenser 200 to the turntable 135. In this embodiment, two
pusher carriers are provided, one for each pusher arm.
[0112] FIG. 20 shows a side view of the pallet dispensing system of
FIG. 19. In FIG. 20, the dispenser pusher arm 232 moves through the
pallet magazine 201 to push the lowermost pallet 150 to the
turntable 135 for loading. Simultaneously, a palletized load 362 is
moved from the turntable 135 to the load pickup station 364 by the
turntable pusher arm 350. Once on the turntable, a load is built on
the pallet. Subsequently, relative rotation is provided between the
dispenser (not shown) and the palletized load to wrap packaging
material around the sides of the load.
[0113] Other embodiments of the invention will be apparent to those
skilled in the art from consideration of the specification and
practice of the invention disclosed herein. It is intended that the
specification and examples be considered as exemplary only, with a
true scope and spirit of the invention being indicated by the
following claims.
* * * * *